WorldWideScience

Sample records for binaural task dynamic

  1. On the use of binaural recordings for dynamic binaural reproduction

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.; Christensen, Flemming

    Binaural recordings are considered applicable only for static binaural reproduction. That is, playback of binaural recordings can only reproduce the sound field captured for the fixed position and orientation of the recording head. However, given some conditions it is possible to use binaural...... recordings for the reproduction of binaural signals that change according to the listener actions, i.e. dynamic binaural reproduction. Here we examine the conditions that allow for such dynamic recording/playback configuration and discuss advantages and disadvantages. Analysis and discussion focus on two...... case studies of reproduction of background sound in a car interior and of the rowing sound captured from elite athletes....

  2. Microphone arrays and sound field decomposition for dynamic binaural recording

    OpenAIRE

    Bernschütz, Benjamin

    2016-01-01

    This thesis discusses a field-related recording technique based on microphone arrays and orthogonal sound field decomposition that delivers a suitable description for dynamic binaural reproduction. Dynamic binaural reproduction refers to a mostly headphone-based reproduction method that allows for presenting localizable virtual sources and accounts for the head movements of the recipient in order to decouple them from the spatial orientation of the virtual auditory scene. Increased source loc...

  3. Processing of Binaural Pitch Stimuli in Hearing-Impaired Listeners

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten

    2009-01-01

    binaural integration mechanisms. This study investigated to what extent basic auditory measures of binaural processing as well as cognitive abilities are correlated with the ability of hearing-impaired listeners to perceive binaural pitch. Subjects from three groups (1: normal-hearing; 2: cochlear...... masking level differences and binaural intelligibility level differences than subjects from group 1, but did not necessarily show reduced scores in a lexical decision task and a reading span test. Overall, these findings confirm that binaural pitch perception is either immediate or absent in hearing...... binaural processing, but not to imply reduced cognitive function....

  4. The technology of binaural listening

    CERN Document Server

    2013-01-01

    This book reports on the application of advanced models of the human binaural hearing system in modern technology, among others, in the following areas:  binaural analysis of aural scenes, binaural de-reverberation, binaural quality assessment of audio channels, loudspeakers and performance spaces, binaural perceptual coding, binaural processing in hearing aids and cochlea implants, binaural systems in robots, binaural/tactile human-machine interfaces, speech-intelligibility prediction in rooms and/or multi-speaker scenarios. An introduction to binaural modeling and an outlook to the future are provided. Further, the book features a MATLAB toolbox to enable readers to construct their own dedicated binaural models on demand.

  5. The impact of binaural beats on creativity

    Directory of Open Access Journals (Sweden)

    Susan A. Reedijk

    2013-11-01

    Full Text Available Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale – mood State questionnaire (PANAS-S and affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs. Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBR were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

  6. Evaluation of dynamic binaural reproduction system for live transmitted xylophone recording

    DEFF Research Database (Denmark)

    Madsen, Esben; Markovic, Milos; Olesen, Søren Krarup; Hoffmann, Pablo F.; Hammershøi, Dorte

    For a special teaching application of the telepresence research project BEAMING, a scenario of a remote teacher (the Visitor) teaching a local student to play a xylophone through an embodiment is defined. In order to achieve this, a system is required to record, transmit and render the sound of the...... xylophone to the teacher in a dynamic scene. In an implementation of such a system, the xylophone is recorded using a mono recording technique. The signal is then processed to spread out the sound of the distributed sound source as multiple point sources in the virtual scene experienced by the Visitor...... listener with a rendering using the described system. The evaluation is done with a basis in methods previously used for evaluating the subjective sensation of presence in virtual reality systems, mainly based on questionnaires....

  7. Binaural Loudness Constancy.

    Science.gov (United States)

    Culling, John F; Dare, Helen

    2016-01-01

    In binaural loudness summation, diotic presentation of a sound usually produces greater loudness than monaural presentation. However, experiments using loudspeaker presentation with and without earplugs find that magnitude estimates of loudness are little altered by the earplug, suggesting a form of loudness constancy. We explored the significance of controlling stimulation of the second ear using meatal occlusion as opposed to the deactivation of one earphone. We measured the point of subjective loudness equality (PSLE) for monaural vs. binaural presentation using an adaptive technique for both speech and noise. These stimuli were presented in a reverberant room over a loudspeaker to the right of the listener, or over lightweight headphones. Using the headphones, stimuli were either presented dry, or matched to those of the loudspeaker by convolution with impulse responses measured from the loudspeaker to the listener position, using an acoustic manikin. The headphone response was also compensated. Using the loudspeaker, monaural presentation was achieved by instructing the listener to block the left ear with a finger. Near perfect binaural loudness constancy was observed using loudspeaker presentation, while there was a summation effect of 3-6 dB for both headphone conditions. However, only partial constancy was observed when meatal occlusion was simulated. These results suggest that there may be contributions to binaural loudness constancy from residual low frequencies at the occluded ear as well as a cognitive element, which is activated by the knowledge that one ear is occluded. PMID:27080647

  8. Directional dependence of binaural loudness

    DEFF Research Database (Denmark)

    Ellermeier, Wolfgang; Sivonen, Ville Pekka

    2006-01-01

    of experiments determining the effect of sound incidence angle on loudness[1,2,3,4]. The basic experiment to be reported on here was conducted in an anechoic chamber, in which loudspeakers were mounted to present sounds from a number of directions both in the horizontal, and median planes. The...... subject’s task was to produce a loudness match to a frontal reference location, and matches were obtained via a two-interval adaptive forced-choice procedure. Narrow-band noises were used, in order to investigate the frequency-specific effects of direction on loudness. Furthermore, individual HRTFs were...... measured for each incidence angle, in order to relate the changes in actual at-ear exposure to the observed changes in loudness as a function of sound incidence. Combining the listening-test data with the physical measurements, an attempt was made to model the binaural summation underlying the directional...

  9. A new perspective on binaural integration using response time methodology: super capacity revealed in conditions of binaural masking release.

    Science.gov (United States)

    Lentz, Jennifer J; He, Yuan; Townsend, James T

    2014-01-01

    This study applied reaction-time based methods to assess the workload capacity of binaural integration by comparing reaction time (RT) distributions for monaural and binaural tone-in-noise detection tasks. In the diotic contexts, an identical tone + noise stimulus was presented to each ear. In the dichotic contexts, an identical noise was presented to each ear, but the tone was presented to one of the ears 180° out of phase with respect to the other ear. Accuracy-based measurements have demonstrated a much lower signal detection threshold for the dichotic vs. the diotic conditions, but accuracy-based techniques do not allow for assessment of system dynamics or resource allocation across time. Further, RTs allow comparisons between these conditions at the same signal-to-noise ratio. Here, we apply a reaction-time based capacity coefficient, which provides an index of workload efficiency and quantifies the resource allocations for single ear vs. two ear presentations. We demonstrate that the release from masking generated by the addition of an identical stimulus to one ear is limited-to-unlimited capacity (efficiency typically less than 1), consistent with less gain than would be expected by probability summation. However, the dichotic presentation leads to a significant increase in workload capacity (increased efficiency)-most specifically at lower signal-to-noise ratios. These experimental results provide further evidence that configural processing plays a critical role in binaural masking release, and that these mechanisms may operate more strongly when the signal stimulus is difficult to detect, albeit still with nearly 100% accuracy. PMID:25202254

  10. A New Perspective on Binaural Integration Using Response Time Methodology: Super Capacity Revealed in Conditions of Binaural Masking Release

    Directory of Open Access Journals (Sweden)

    Jennifer eLentz

    2014-08-01

    Full Text Available This study applied reaction-time based methods to assess the workload capacity of binaural integration by comparing reaction time distributions for monaural and binaural tone-in-noise detection tasks. In the diotic contexts, an identical tone + noise stimulus was presented to each ear. In the dichotic contexts, an identical noise was presented to each ear, but the tone was presented to one of the ears 180o out of phase with respect to the other ear. Accuracy-based measurements have demonstrated a much lower signal detection threshold for the dichotic versus the diotic conditions, but accuracy-based techniques do not allow for assessment of system dynamics or resource allocation across time. Further, reaction times allow comparisons between these conditions at the same signal-to-noise ratio. Here, we apply a reaction-time based capacity coefficient, which provides an index of workload efficiency and quantifies the resource allocations for single ear versus two ear presentations. We demonstrate that the release from masking generated by the addition of an identical stimulus to one ear is limited-to-unlimited capacity (efficiency typically less than 1, consistent with less gain than would be expected by probability summation. However, the dichotic presentation leads to a significant increase in workload capacity (increased efficiency – most specifically at lower signal-to-noise ratios. These experimental results provide further evidence that configural processing plays a critical role in binaural masking release, and that these mechanisms may operate more strongly when the signal stimulus is difficult to detect, albeit still with nearly 100% accuracy.

  11. Instructional Multiple Binaural Stethoscope

    OpenAIRE

    Catalina C. Platon

    2015-01-01

    The stethoscope is an acoustic medical device for auscultation where human ear plays significant part. Long before doctors practiced immediate auscultation meaning placing ear directly on patient’s body by Salinsky (1990), then monaural introduced by Laennec; later binaural, Comins’s invention and Cammann developed further. Several decades numerous innovations made predominantly over chestpiece some had drawbacks. Dr Littman introduced teaching stethoscope with two headset and ...

  12. The Effect of Asymmetrical Signal Degradation on Binaural Speech Recognition in Children and Adults.

    Science.gov (United States)

    Rothpletz, Ann M.; Tharpe, Anne Marie; Grantham, D. Wesley

    2004-01-01

    To determine the effect of asymmetrical signal degradation on binaural speech recognition, 28 children and 14 adults were administered a sentence recognition task amidst multitalker babble. There were 3 listening conditions: (a) monaural, with mild degradation in 1 ear; (b) binaural, with mild degradation in both ears (symmetric degradation); and…

  13. Instructional Multiple Binaural Stethoscope

    Directory of Open Access Journals (Sweden)

    Catalina C. Platon

    2015-12-01

    Full Text Available The stethoscope is an acoustic medical device for auscultation where human ear plays significant part. Long before doctors practiced immediate auscultation meaning placing ear directly on patient’s body by Salinsky (1990, then monaural introduced by Laennec; later binaural, Comins’s invention and Cammann developed further. Several decades numerous innovations made predominantly over chestpiece some had drawbacks. Dr Littman introduced teaching stethoscope with two headset and researcher utilized as prior art.Experimental research method used and the study aimed to determine accuracy and measurement of speed of the device in terms of systolic and diastolic blood pressure and acceptability of user. The subjects were 19 clients and 27 nursing students, government /private registered nurses. The device are comparable to single binaural stethoscope in accuracy performance; speed of sound, former is slightly higher than the latter but still considered as normal; the device are acceptable to users; the utility model have no significant difference in accuracy performance and speed measurements of systolic and diastolic. The utility model may be tried in any acoustic activities and may be pilot tested to the Universities animal science courses, veterinary medicine other Colleges of Nursing and all health allied courses.

  14. Binaural pitch perception in hearing-impaired listeners

    DEFF Research Database (Denmark)

    Dau, Torsten; Santurette, Sébastien; Strelcyk, Olaf

    2007-01-01

    When two white noises differing only in phase in a particular frequency range are presented simultaneously each to one of our ears, a pitch sensation may be perceived inside the head. This phenomenon, called ’binaural pitch’ or ’dichotic pitch’, can be produced by frequency-dependent interaural...... phasedifference patterns. The evaluation of these interaural phase differences depends on the functionality of the binaural auditory system and the spectro-temporal information at its input. A melody recognition task was performed in the present study using pure-tone stimuli and six different types of noises that...... can generate a binaural pitch sensation. Normal-hearing listeners and hearing-impaired listeners with different kinds of hearing impairment participated in the experiment....

  15. A new perspective on binaural integration using response time methodology: super capacity revealed in conditions of binaural masking release

    OpenAIRE

    Lentz, Jennifer J.; He, Yuan; Townsend, James T.

    2014-01-01

    This study applied reaction-time based methods to assess the workload capacity of binaural integration by comparing reaction time (RT) distributions for monaural and binaural tone-in-noise detection tasks. In the diotic contexts, an identical tone + noise stimulus was presented to each ear. In the dichotic contexts, an identical noise was presented to each ear, but the tone was presented to one of the ears 180° out of phase with respect to the other ear. Accuracy-based measurements have demon...

  16. A New Perspective on Binaural Integration Using Response Time Methodology: Super Capacity Revealed in Conditions of Binaural Masking Release

    OpenAIRE

    Jennifer Lentz; Townsend, James T.

    2014-01-01

    This study applied reaction-time based methods to assess the workload capacity of binaural integration by comparing reaction time distributions for monaural and binaural tone-in-noise detection tasks. In the diotic contexts, an identical tone + noise stimulus was presented to each ear. In the dichotic contexts, an identical noise was presented to each ear, but the tone was presented to one of the ears 180o out of phase with respect to the other ear. Accuracy-based measurements have demonstra...

  17. Spectral and binaural loudness summation for hearing-impaired listeners.

    Science.gov (United States)

    Oetting, Dirk; Hohmann, Volker; Appell, Jens-E; Kollmeier, Birger; Ewert, Stephan D

    2016-05-01

    Sensorineural hearing loss typically results in a steepened loudness function and a reduced dynamic range from elevated thresholds to uncomfortably loud levels for narrowband and broadband signals. Restoring narrowband loudness perception for hearing-impaired (HI) listeners can lead to overly loud perception of broadband signals and it is unclear how binaural presentation affects loudness perception in this case. Here, loudness perception quantified by categorical loudness scaling for nine normal-hearing (NH) and ten HI listeners was compared for signals with different bandwidth and different spectral shape in monaural and in binaural conditions. For the HI listeners, frequency- and level-dependent amplification was used to match the narrowband monaural loudness functions of the NH listeners. The average loudness functions for NH and HI listeners showed good agreement for monaural broadband signals. However, HI listeners showed substantially greater loudness for binaural broadband signals than NH listeners: on average a 14.1 dB lower level was required to reach "very loud" (range 30.8 to -3.7 dB). Overall, with narrowband loudness compensation, a given binaural loudness for broadband signals above "medium loud" was reached at systematically lower levels for HI than for NH listeners. Such increased binaural loudness summation was not found for loudness categories below "medium loud" or for narrowband signals. Large individual variations in the increased loudness summation were observed and could not be explained by the audiogram or the narrowband loudness functions. PMID:27006003

  18. Eye Movements Reveal Dynamics of Task Control

    Science.gov (United States)

    Mayr, Ulrich; Kuhns, David; Rieter, Miranda

    2013-01-01

    With the goal to determine the cognitive architecture that underlies flexible changes of control settings, we assessed within-trial and across-trial dynamics of attentional selection by tracking of eye movements in the context of a cued task-switching paradigm. Within-trial dynamics revealed a switch-induced, discrete delay in onset of…

  19. Testing the binaural equal-loudness-ratio hypothesis with hearing-impaired listeners1

    OpenAIRE

    Marozeau, Jeremy; Florentine, Mary

    2009-01-01

    The primary purpose of the present experiment was to test whether the binaural equal-loudness-ratio hypothesis (i.e., the loudness ratio between monaural and binaural tones presented at the same Sound Pressure Level, SPL, is independent of SPL) holds for hearing-impaired listeners with bilaterally symmetrical hearing losses. The outcome of this experiment provided a theoretical construct for modeling loudness-growth functions. A cross-modality matching task between string length and tones was...

  20. Cortical subnetwork dynamics during human language tasks.

    Science.gov (United States)

    Collard, Maxwell J; Fifer, Matthew S; Benz, Heather L; McMullen, David P; Wang, Yujing; Milsap, Griffin W; Korzeniewska, Anna; Crone, Nathan E

    2016-07-15

    Language tasks require the coordinated activation of multiple subnetworks-groups of related cortical interactions involved in specific components of task processing. Although electrocorticography (ECoG) has sufficient temporal and spatial resolution to capture the dynamics of event-related interactions between cortical sites, it is difficult to decompose these complex spatiotemporal patterns into functionally discrete subnetworks without explicit knowledge of each subnetwork's timing. We hypothesized that subnetworks corresponding to distinct components of task-related processing could be identified as groups of interactions with co-varying strengths. In this study, five subjects implanted with ECoG grids over language areas performed word repetition and picture naming. We estimated the interaction strength between each pair of electrodes during each task using a time-varying dynamic Bayesian network (tvDBN) model constructed from the power of high gamma (70-110Hz) activity, a surrogate for population firing rates. We then reduced the dimensionality of this model using principal component analysis (PCA) to identify groups of interactions with co-varying strengths, which we term functional network components (FNCs). This data-driven technique estimates both the weight of each interaction's contribution to a particular subnetwork, and the temporal profile of each subnetwork's activation during the task. We found FNCs with temporal and anatomical features consistent with articulatory preparation in both tasks, and with auditory and visual processing in the word repetition and picture naming tasks, respectively. These FNCs were highly consistent between subjects with similar electrode placement, and were robust enough to be characterized in single trials. Furthermore, the interaction patterns uncovered by FNC analysis correlated well with recent literature suggesting important functional-anatomical distinctions between processing external and self-produced speech. Our

  1. A high-density EEG investigation into steady state binaural beat stimulation.

    Directory of Open Access Journals (Sweden)

    Peter Goodin

    Full Text Available Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz or Beta (16 Hz frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

  2. A high-density EEG investigation into steady state binaural beat stimulation.

    Science.gov (United States)

    Goodin, Peter; Ciorciari, Joseph; Baker, Kate; Carey, Anne-Marie; Carrey, Anne-Marie; Harper, Michelle; Kaufman, Jordy

    2012-01-01

    Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz) or Beta (16 Hz) frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others. PMID:22496862

  3. Binaural loudness summation for directional sounds

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Ellermeier, Wolfgang

    2006-01-01

    binaural loudness summation of the at-ear signals. Even though the effects of HRTFs were taken into account, considerable individual differences in the binaural summation of loudness remained. In order to create conditions in which the directional at-ear changes were identical for all participants, the...

  4. Binaural Loudness Summation in the Hearing Impaired.

    Science.gov (United States)

    Hawkins, David B.; And Others

    1987-01-01

    Binaural loudness summation was measured using three different paradigms with 10 normally hearing and 20 bilaterally symmetrical high-frequency sensorineural hearing loss subjects. Binaural summation increased with presentation level using the loudness matching procedure, with values in the 6-10 dB range. Summation decreased with level using the…

  5. Control of earphone produced binaural signals

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Hoffmann, Pablo F.

    2011-01-01

    While most people keep a high attention to the significance of the binaural recording method, whether it is e.g. individual or non-individual (as e.g. artificial head recording), many pay less attention to the type of earphone used to reproduce the binaural signals, and to the accurate control of...

  6. Parametric binaural synthesis: Background, applications and standards

    NARCIS (Netherlands)

    Breebaart, D.J.; Nater, F.; Kohlrausch, A.G.

    2010-01-01

    The amount of information present in HRTFs and the required processing capabilities for real-time and inter-active binaural rendering have long been a challenge for many applications for binaural rendering. More recently, parametric methods to capture the perceptually-relevant information from HRTFs

  7. DYNAMIC TASK SCHEDULING ON MULTICORE AUTOMOTIVE ECUS

    Directory of Open Access Journals (Sweden)

    Geetishree Mishra

    2014-12-01

    Full Text Available Automobile manufacturers are controlled by stringent govt. regulations for safety and fuel emissions and motivated towards adding more advanced features and sophisticated applications to the existing electronic system. Ever increasing customer’s demands for high level of comfort also necessitate providing even more sophistication in vehicle electronics system. All these, directly make the vehicle software system more complex and computationally more intensive. In turn, this demands very high computational capability of the microprocessor used in electronic control unit (ECU. In this regard, multicore processors have already been implemented in some of the task rigorous ECUs like, power train, image processing and infotainment. To achieve greater performance from these multicore processors, parallelized ECU software needs to be efficiently scheduled by the underlaying operating system for execution to utilize all the computational cores to the maximum extent possible and meet the real time constraint. In this paper, we propose a dynamic task scheduler for multicore engine control ECU that provides maximum CPU utilization, minimized preemption overhead, minimum average waiting time and all the tasks meet their real time deadlines while compared to the static priority scheduling suggested by Automotive Open Systems Architecture (AUTOSAR

  8. Dynamic Task Scheduling on Multicore Automotive ECUs

    Directory of Open Access Journals (Sweden)

    Geetishree Mishra

    2014-12-01

    Full Text Available Automobile manufacturers are controlled by stringen t govt. regulations for safety and fuel emissions a nd motivated towards adding more advanced features and sophisticated applications to the existing electro nic system. Ever increasing customer’s demands for high level of comfort also necessitate providing even m ore sophistication in vehicle electronics system. All t hese, directly make the vehicle software system mor e complex and computationally more intensive. In turn , this demands very high computational capability o f the microprocessor used in electronic control unit (ECU. In this regard, multicore processors have already been implemented in some of the task rigoro us ECUs like, power train, image processing and infotainment. To achieve greater performance from t hese multicore processors, parallelized ECU softwar e needs to be efficiently scheduled by the underlayin g operating system for execution to utilize all the computational cores to the maximum extent possible and meet the real time constraint. In this paper, w e propose a dynamic task scheduler for multicore engi ne control ECU that provides maximum CPU utilization, minimized preemption overhead, minimum average waiting time and all the tasks meet their real time deadlines while compared to the static pr iority scheduling suggested by Automotive Open Syst ems Architecture (AUTOSAR.

  9. Dynamical Models of Task Organization in Social Insect Colonies.

    Science.gov (United States)

    Kang, Yun; Theraulaz, Guy

    2016-05-01

    The organizations of insect societies, such as division of labor, task allocation, collective regulation, mass action responses, have been considered as main reasons for the ecological success. In this article, we propose and study a general modeling framework that includes the following three features: (a) the average internal response threshold for each task (the internal factor); (b) social network communications that could lead to task switching (the environmental factor); and (c) dynamical changes of task demands (the external factor). Since workers in many social insect species exhibit age polyethism, we also extend our model to incorporate age polyethism in which worker task preferences change with age. We apply our general modeling framework to the cases of two task groups: the inside colony task versus the outside colony task. Our analytical study of the models provides important insights and predictions on the effects of colony size, social communication, and age-related task preferences on task allocation and division of labor in the adaptive dynamical environment. Our study implies that the smaller size colony invests its resource for the colony growth and allocates more workers in the risky tasks such as foraging while the larger colony shifts more workers to perform the safer tasks inside the colony. Social interactions among different task groups play an important role in shaping task allocation depending on the relative cost and demands of the tasks. PMID:27125656

  10. DYNAMIC TASK PARTITIONING MODEL IN PARALLEL COMPUTING

    Directory of Open Access Journals (Sweden)

    Javed Ali

    2012-04-01

    Full Text Available Parallel computing systems compose task partitioning strategies in a true multiprocessing manner. Such systems share the algorithm and processing unit as computing resources which leads to highly inter process communications capabilities. The main part of the proposed algorithm is resource management unit which performs task partitioning and co-scheduling .In this paper, we present a technique for integrated task partitioning and co-scheduling on the privately owned network. We focus on real-time and non preemptive systems. A large variety of experiments have been conducted on the proposed algorithm using synthetic and real tasks. Goal of computation model is to provide a realistic representation of the costs of programming The results show the benefit of the task partitioning. The main characteristics of our method are optimal scheduling and strong link between partitioning, scheduling and communication. Some important models for task partitioning are also discussed in the paper. We target the algorithm for task partitioning which improve the inter process communication between the tasks and use the recourses of the system in the efficient manner. The proposed algorithm contributes the inter-process communication cost minimization amongst the executing processes.

  11. Learning Probabilistic Relational Dynamics for Multiple Tasks

    OpenAIRE

    Deshpande, Ashwin; Milch, Brian; Zettlemoyer, Luke S.; Kaelbling, Leslie Pack

    2008-01-01

    The ways in which an agent's actions affect the world can often be modeled compactly using a set of relational probabilistic planning rules. This extended abstract addresses the problem of learning such rule sets for multiple related tasks. We take a hierarchical Bayesian approach, in which the system learns a prior distribution over rule sets. We present a class of prior distributions parameterized by a rule set prototype that is stochastically modified to produce a task-specific rule se...

  12. Better Decision Making in Complex, Dynamic Tasks

    Science.gov (United States)

    Qudrat-Ullah, Hassan

    Complex managerial problems abound. For instance, project costs continue to overrun, friendly fire events, where a fighter plane bombs its own troops on ground, appear unavoidable, and overexploitation of renewables continues unabated. In essence, managers and policymakers today face problems that are increasingly complex, and dynamic. Therefore, the need for effective and efficient decisional aids is always on the rise.

  13. Analysis and Modeling of Control Tasks in Dynamic Systems

    DEFF Research Database (Denmark)

    Ursem, Rasmus Kjær; Krink, Thiemo; Jensen, Mikkel Thomas;

    2002-01-01

    -case generators (TCGs), which requires a systematic analysis of dynamic optimization tasks. So far, only a few TCGs have been suggested. Our investigation leads to the conclusion that these TCGs are not capable of generating realistic dynamic benchmark tests. The result of our research is the design of a new TCG...

  14. Range dependent characteristics in the head-related transfer functions of a bat-head cast: part 2. Binaural characteristics

    International Nuclear Information System (INIS)

    Further innovations in bio-inspired engineering based on biosonar systems, such as bats, may arise from more detailed understanding of the underlying acoustic processes. This includes the range-dependent properties of bat heads and ears, particularly at the higher frequencies of bat vocalizations. In a companion paper Kim et al (2012 Bioinspir. Biomim.), range-dependent head-related transfer functions of a bat head cast were investigated up to 100 kHz at either ear (i.e. monaural features). The current paper extends this to consider range-dependent spectral and temporal disparities between the two ears (i.e. binaural features), using experimental data and a spherical model of a bat head to provide insights into the physical basis for these features. It was found that binaural temporal and high-frequency binaural spectral features are approximately independent of distance, having the effect of decreasing their angular resolution at close range. In contrast, low-frequency binaural spectral features are strongly distance-dependent, such that angular sensitivity can be maintained by lowering the frequency of the echolocation emission at close range. Together with the companion paper Kim et al, we speculate that distance-dependent low-frequency monaural and binaural features at short range might help explain why some species of bats that drop the frequency of their calls on target approach while approaching a target. This also provides an impetus for the design of effective emissions in sonar engineering applied to similar tasks. (paper)

  15. Beamforming under Quantization Errors in Wireless Binaural Hearing Aids

    Directory of Open Access Journals (Sweden)

    Kees Janse

    2008-09-01

    Full Text Available Improving the intelligibility of speech in different environments is one of the main objectives of hearing aid signal processing algorithms. Hearing aids typically employ beamforming techniques using multiple microphones for this task. In this paper, we discuss a binaural beamforming scheme that uses signals from the hearing aids worn on both the left and right ears. Specifically, we analyze the effect of a low bit rate wireless communication link between the left and right hearing aids on the performance of the beamformer. The scheme is comprised of a generalized sidelobe canceller (GSC that has two inputs: observations from one ear, and quantized observations from the other ear, and whose output is an estimate of the desired signal. We analyze the performance of this scheme in the presence of a localized interferer as a function of the communication bit rate using the resultant mean-squared error as the signal distortion measure.

  16. Beamforming under Quantization Errors in Wireless Binaural Hearing Aids

    Directory of Open Access Journals (Sweden)

    Srinivasan Sriram

    2008-01-01

    Full Text Available Improving the intelligibility of speech in different environments is one of the main objectives of hearing aid signal processing algorithms. Hearing aids typically employ beamforming techniques using multiple microphones for this task. In this paper, we discuss a binaural beamforming scheme that uses signals from the hearing aids worn on both the left and right ears. Specifically, we analyze the effect of a low bit rate wireless communication link between the left and right hearing aids on the performance of the beamformer. The scheme is comprised of a generalized sidelobe canceller (GSC that has two inputs: observations from one ear, and quantized observations from the other ear, and whose output is an estimate of the desired signal. We analyze the performance of this scheme in the presence of a localized interferer as a function of the communication bit rate using the resultant mean-squared error as the signal distortion measure.

  17. Comparison between bilateral cochlear implants and Neurelec Digisonic(®) SP Binaural cochlear implant: speech perception, sound localization and patient self-assessment.

    Science.gov (United States)

    Bonnard, Damien; Lautissier, Sylvie; Bosset-Audoit, Amélie; Coriat, Géraldine; Beraha, Max; Maunoury, Antoine; Martel, Jacques; Darrouzet, Vincent; Bébéar, Jean-Pierre; Dauman, René

    2013-01-01

    An alternative to bilateral cochlear implantation is offered by the Neurelec Digisonic(®) SP Binaural cochlear implant, which allows stimulation of both cochleae within a single device. The purpose of this prospective study was to compare a group of Neurelec Digisonic(®) SP Binaural implant users (denoted BINAURAL group, n = 7) with a group of bilateral adult cochlear implant users (denoted BILATERAL group, n = 6) in terms of speech perception, sound localization, and self-assessment of health status and hearing disability. Speech perception was assessed using word recognition at 60 dB SPL in quiet and in a 'cocktail party' noise delivered through five loudspeakers in the hemi-sound field facing the patient (signal-to-noise ratio = +10 dB). The sound localization task was to determine the source of a sound stimulus among five speakers positioned between -90° and +90° from midline. Change in health status was assessed using the Glasgow Benefit Inventory and hearing disability was evaluated with the Abbreviated Profile of Hearing Aid Benefit. Speech perception was not statistically different between the two groups, even though there was a trend in favor of the BINAURAL group (mean percent word recognition in the BINAURAL and BILATERAL groups: 70 vs. 56.7% in quiet, 55.7 vs. 43.3% in noise). There was also no significant difference with regard to performance in sound localization and self-assessment of health status and hearing disability. On the basis of the BINAURAL group's performance in hearing tasks involving the detection of interaural differences, implantation with the Neurelec Digisonic(®) SP Binaural implant may be considered to restore effective binaural hearing. Based on these first comparative results, this device seems to provide benefits similar to those of traditional bilateral cochlear implantation, with a new approach to stimulate both auditory nerves. PMID:23548561

  18. Dynamic Task Optimization in Remote Diabetes Monitoring Systems

    Science.gov (United States)

    Suh, Myung-kyung; Woodbridge, Jonathan; Moin, Tannaz; Lan, Mars; Alshurafa, Nabil; Samy, Lauren; Mortazavi, Bobak; Ghasemzadeh, Hassan; Bui, Alex; Ahmadi, Sheila; Sarrafzadeh, Majid

    2016-01-01

    Diabetes is the seventh leading cause of death in the United States, but careful symptom monitoring can prevent adverse events. A real-time patient monitoring and feedback system is one of the solutions to help patients with diabetes and their healthcare professionals monitor health-related measurements and provide dynamic feedback. However, data-driven methods to dynamically prioritize and generate tasks are not well investigated in the domain of remote health monitoring. This paper presents a wireless health project (WANDA) that leverages sensor technology and wireless communication to monitor the health status of patients with diabetes. The WANDA dynamic task management function applies data analytics in real-time to discretize continuous features, applying data clustering and association rule mining techniques to manage a sliding window size dynamically and to prioritize required user tasks. The developed algorithm minimizes the number of daily action items required by patients with diabetes using association rules that satisfy a minimum support, confidence and conditional probability thresholds. Each of these tasks maximizes information gain, thereby improving the overall level of patient adherence and satisfaction. Experimental results from applying EM-based clustering and Apriori algorithms show that the developed algorithm can predict further events with higher confidence levels and reduce the number of user tasks by up to 76.19 %.

  19. Prospective Memory and Task Interference in a Continuous Monitoring Dynamic Display Task

    Science.gov (United States)

    Loft, Shayne; Remington, Roger W.

    2010-01-01

    Theories and methods from the prospective memory literature were used to anticipate how individuals would maintain and retrieve intentions in a continuous monitoring dynamic display task. Participants accepted aircraft into sectors and detected aircraft conflicts during an air traffic control simulation. They were sometimes required to substitute…

  20. Loudness enhancement - Monaural, binaural, and dichotic

    Science.gov (United States)

    Elmasian, R.; Galambos, R.

    1975-01-01

    When one tone burst (T) precedes another (S) by 100 msec, variations in the intensity of T systematically influence the loudness of S. When T is more intense than S, S is increased; and when T is less intense, S loudness is decreased. This occurs in monaural, binaural, and dichotic paradigms of signal presentation. When T and S are presented to the same ear (monaural or binaural), there is more enhancement with less intersubject variability than when they are presented to different ears (dichotic paradigm). Monaural enhancements as large as 30 dB can readily be demonstrated, but decrements rarely exceed 5 dB. Possible physiological mechanisms are discussed for this loudness enhancement, which apparently shares certain characteristics with time-order error, assimilation, and temporal partial masking experiments.

  1. Analog VLSI model of binaural hearing

    OpenAIRE

    Mead, Carver A.; Arreguit, Xavier; Lazzaro, John

    1991-01-01

    The stereausis model of biological auditory processing was proposed as a representation that encodes both binaural and spectral information in a unified framework. We describe a working analog VLSI chip that implements this model of early auditory processing in the brain. The chip is a 100 000-transistor integrated circuit that computes the stereausis representation in real time, using continuous-time analog processing. The chip receives two audio inputs, representing sou...

  2. Distributed signal processing for binaural hearing aids

    OpenAIRE

    Roy, Olivier

    2008-01-01

    Over the last centuries, hearing aids have evolved from crude and bulky horn-shaped instruments to lightweight and almost invisible digital signal processing devices. While most of the research has focused on the design of monaural apparatus, the use of a wireless link has been recently advocated to enable data transfer between hearing aids such as to obtain a binaural system. The availability of a wireless link offers brand new perspectives but also poses great technical challenges. It requi...

  3. Heuristic Scheduling Algorithm Oriented Dynamic Tasks for Imaging Satellites

    Directory of Open Access Journals (Sweden)

    Maocai Wang

    2014-01-01

    Full Text Available Imaging satellite scheduling is an NP-hard problem with many complex constraints. This paper researches the scheduling problem for dynamic tasks oriented to some emergency cases. After the dynamic properties of satellite scheduling were analyzed, the optimization model is proposed in this paper. Based on the model, two heuristic algorithms are proposed to solve the problem. The first heuristic algorithm arranges new tasks by inserting or deleting them, then inserting them repeatedly according to the priority from low to high, which is named IDI algorithm. The second one called ISDR adopts four steps: insert directly, insert by shifting, insert by deleting, and reinsert the tasks deleted. Moreover, two heuristic factors, congestion degree of a time window and the overlapping degree of a task, are employed to improve the algorithm’s performance. Finally, a case is given to test the algorithms. The results show that the IDI algorithm is better than ISDR from the running time point of view while ISDR algorithm with heuristic factors is more effective with regard to algorithm performance. Moreover, the results also show that our method has good performance for the larger size of the dynamic tasks in comparison with the other two methods.

  4. Task-Based Cohesive Evolution of Dynamic Brain Networks

    Science.gov (United States)

    Davison, Elizabeth

    2014-03-01

    Applications of graph theory to neuroscience have resulted in significant progress towards a mechanistic understanding of the brain. Functional network representation of the brain has linked efficient network structure to psychometric intelligence and altered configurations with disease. Dynamic graphs provide us with tools to further study integral properties of the brain; specifically, the mathematical convention of hyperedges has allowed us to study the brain's cross-linked structure. Hyperedges capture the changes in network structure by identifying groups of brain regions with correlation patterns that change cohesively through time. We performed a hyperedge analysis on functional MRI data from 86 subjects and explored the cohesive evolution properties of their functional brain networks as they performed a series of tasks. Our results establish the hypergraph as a useful measure in understanding functional brain dynamics over tasks and reveal characteristic differences in the co-evolution structure of task-specific networks.

  5. Integrated Task and Data Parallel Support for Dynamic Applications

    Directory of Open Access Journals (Sweden)

    James M. Rehg

    1999-01-01

    Full Text Available There is an emerging class of real‐time interactive applications that require the dynamic integration of task and data parallelism. An example is the Smart Kiosk, a free‐standing computer device that provides information and entertainment to people in public spaces. The kiosk interface is computationally demanding: It employs vision and speech sensing and an animated graphical talking face for output. The computational demands of an interactive kiosk can vary widely with the number of customers and the state of the interaction. Unfortunately this makes it difficult to apply current techniques for integrated task and data parallel computing, which can produce optimal decompositions for static problems. Using experimental results from a color‐based people tracking module, we demonstrate the existence of a small number of distinct operating regimes in the kiosk application. We refer to this type of program behavior as constrained dynamism. An application exhibiting constrained dynamism can execute efficiently by dynamically switching among a small number of statically determined fixed data parallel strategies. We present a novel framework for integrating task and data parallelism for applications that exhibit constrained dynamism. Our solution has been implemented using Stampede, a cluster programming system developed at the Cambridge Research Laboratory.

  6. Exploiting Dynamic Workload Variation in Low Energy Preemptive Task Scheduling

    CERN Document Server

    Leung, Lap-Fai; Hu, Xiaobo Sharon

    2011-01-01

    A novel energy reduction strategy to maximally exploit the dynamic workload variation is proposed for the offline voltage scheduling of preemptive systems. The idea is to construct a fully-preemptive schedule that leads to minimum energy consumption when the tasks take on approximately the average execution cycles yet still guarantees no deadline violation during the worst-case scenario. End-time for each sub-instance of the tasks obtained from the schedule is used for the on-line dynamic voltage scaling (DVS) of the tasks. For the tasks that normally require a small number of cycles but occasionally a large number of cycles to complete, such a schedule provides more opportunities for slack utilization and hence results in larger energy saving. The concept is realized by formulating the problem as a Non-Linear Programming (NLP) optimization problem. Experimental results show that, by using the proposed scheme, the total energy consumption at runtime is reduced by as high as 60% for randomly generated task set...

  7. Relating binaural pitch perception to the individual listener's auditory profile

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten

    2012-01-01

    The ability of eight normal-hearing listeners and fourteen listeners with sensorineural hearing loss to detect and identify pitch contours was measured for binaural-pitch stimuli and salience-matched monaurally detectable pitches. In an effort to determine whether impaired binaural pitch percepti...

  8. Task-Phase-Specific Dynamics of Basal Forebrain Neuronal Ensembles

    Directory of Open Access Journals (Sweden)

    Douglas A Nitz

    2014-09-01

    Full Text Available Cortically projecting basal forebrain neurons play a critical role in learning and attention, and their degeneration accompanies age-related impairments in cognition. Despite the impressive anatomical and cell-type complexity of this system, currently available data suggest that basal forebrain neurons lack complexity in their response fields, with activity primarily reflecting only macro-level brain states such as sleep and wake, onset of relevant stimuli and/or reward obtainment. The current study examined the spiking activity of basal forebrain neuron populations across multiple phases of a selective attention task, addressing, in particular, the issue of complexity in ensemble firing patterns across time. Clustering techniques applied to the full population revealed a large number of distinct categories of task-phase-specific activity patterns. Unique population firing-rate vectors defined each task phase and most categories of task-phase-specific firing had counterparts with opposing firing patterns. An analogous set of task-phase-specific firing patterns was also observed in a population of posterior parietal cortex neurons. Thus, consistent with the known anatomical complexity, basal forebrain population dynamics are capable of differentially modulating their cortical targets according to the unique sets of environmental stimuli, motor requirements, and cognitive processes associated with different task phases.

  9. A Binaural Cochlear Implant Sound Coding Strategy Inspired by the Contralateral Medial Olivocochlear Reflex

    OpenAIRE

    Enrique A Lopez-Poveda; Eustaquio-Martín, Almudena; Stohl, Joshua S.; Wolford, Robert D.; Schatzer, Reinhold; Wilson, Blake S.

    2015-01-01

    Objectives: In natural hearing, cochlear mechanical compression is dynamically adjusted via the efferent medial olivocochlear reflex (MOCR). These adjustments probably help understanding speech in noisy environments and are not available to the users of current cochlear implants (CIs). The aims of the present study are to: (1) present a binaural CI sound processing strategy inspired by the control of cochlear compression provided by the contralateral MOCR in natural hearing; and (2) assess th...

  10. Maximally Stabilizing Task Release Control Policy for a Dynamical Queue

    OpenAIRE

    Savla, Ketan; Frazzoli, Emilio

    2009-01-01

    In this paper, we introduce a model of dynamical queue, in which the service time depends on the server utilization history. The proposed queueing model is motivated by widely accepted empirical laws describing human performance as a function of mental arousal. The objective of this paper is to design task release control policies that can stabilize the queue for the maximum possible arrival rate, assuming deterministic arrivals. First, we prove an upper bound on the maximum possible stabiliz...

  11. Efficient coding of spectrotemporal binaural sounds leads to emergence of the auditory space representation

    Directory of Open Access Journals (Sweden)

    Wiktor Mlynarski

    2014-03-01

    Full Text Available To date a number of studies have shown that receptive field shapes of early sensory neurons can be reproduced by optimizing coding efficiency of natural stimulus ensembles. A still unresolved question is whether the efficientcoding hypothesis explains formation of neurons which explicitly represent environmental features of different functional importance. This paper proposes that the spatial selectivity of higher auditory neurons emerges as a direct consequence of learning efficient codes for natural binaural sounds. Firstly, it is demonstrated that a linear efficient coding transform - Independent Component Analysis (ICA trained on spectrograms of naturalistic simulated binaural sounds extracts spatial information present in the signal. A simple hierarchical ICA extension allowing for decoding of sound position is proposed. Furthermore, it is shown that units revealing spatial selectivity can be learned from a binaural recording of a natural auditory scene. In both cases a relatively small subpopulation of learned spectrogram features suffices to perform accurate sound localization. Representation of the auditory space is therefore learned in a purely unsupervised way by maximizing the coding efficiency and without any task-specific constraints. This results imply that efficient coding is a useful strategy for learning structures which allow for making behaviorally vital inferences about the environment.

  12. Preserving binaural hearing of hearing impaired subjects with binaural noise reduction systems for hearing aids

    OpenAIRE

    Van den Bogaert, Tim; Wouters, Jan; Moonen, Marc

    2009-01-01

    Hearing aid users experience great difficulty in understanding speech in noisy environments. This has led to the introduction of noise reduction algorithms in hearing aids. The development of these algorithms is typically done monaurally. However, the human auditory system is a binaural system, which compares and combines the signals received by both ears to perceive a sound source as a single entity in space. Providing two monaural, independently operating, noise reduction sys...

  13. Physiological evidence of interpersonal dynamics in a cooperative production task

    DEFF Research Database (Denmark)

    Mønster, Dan; Håkonsson, Dorthe Døjbak; Eskildsen, Jacob Kjær;

    2016-01-01

    cooperative production task. Moreover, high team synchrony is found indicative of team cohesion, while low team synchrony is found indicative of a teams' decision to adopt a new behavior across multiple production sessions. We conclude that team-level measures of synchrony offer new and complementary......, however, has received comparatively little attention. In the present study, we investigate the coordination dynamics of multiple psychophysiological measures and their utility in capturing emotional dynamics in teams. We use data from an experiment where teams of three people built origami boats together...... in an assembly-line manner while their heart rate, skin conductance, and facial muscle activity were recorded. Our results show that physiological synchrony of skin conductance measures and eletromyographic measures of the corrugator supercilii develops spontaneously among team members during this...

  14. Dynamic Monitoring Reveals Motor Task Characteristics in Prehistoric Technical Gestures.

    Directory of Open Access Journals (Sweden)

    Johannes Pfleging

    Full Text Available Reconstructing ancient technical gestures associated with simple tool actions is crucial for understanding the co-evolution of the human forelimb and its associated control-related cognitive functions on the one hand, and of the human technological arsenal on the other hand. Although the topic of gesture is an old one in Paleolithic archaeology and in anthropology in general, very few studies have taken advantage of the new technologies from the science of kinematics in order to improve replicative experimental protocols. Recent work in paleoanthropology has shown the potential of monitored replicative experiments to reconstruct tool-use-related motions through the study of fossil bones, but so far comparatively little has been done to examine the dynamics of the tool itself. In this paper, we demonstrate that we can statistically differentiate gestures used in a simple scraping task through dynamic monitoring. Dynamics combines kinematics (position, orientation, and speed with contact mechanical parameters (force and torque. Taken together, these parameters are important because they play a role in the formation of a visible archaeological signature, use-wear. We present our new affordable, yet precise methodology for measuring the dynamics of a simple hide-scraping task, carried out using a pull-to (PT and a push-away (PA gesture. A strain gage force sensor combined with a visual tag tracking system records force, torque, as well as position and orientation of hafted flint stone tools. The set-up allows switching between two tool configurations, one with distal and the other one with perpendicular hafting of the scrapers, to allow for ethnographically plausible reconstructions. The data show statistically significant differences between the two gestures: scraping away from the body (PA generates higher shearing forces, but requires greater hand torque. Moreover, most benchmarks associated with the PA gesture are more highly variable than in

  15. Loudness enhancement: Monaural, binaural and dichotic

    Science.gov (United States)

    Elmasian, R. O.; Galambos, R.

    1975-01-01

    It is shown that when one tone burst precedes another by 100 msec variations in the intensity of the first systematically influences the loudness of second. When the first burst is more intense than the second, the second is increased and when the first burst is less intense, the loudness of the second is decreased. This occurs in monaural, binaural and dichotic paradigms of signal presentation. Where both bursts are presented to the same ear there is more enhancement with less intersubject variability than when they are presented to different ears. Monaural enhancements as large as 30 db can readily be demonstrated, but decrements rarely exceed 5 db. Possible physiological mechanisms are discussed for this loudness enhancement, which apparently shares certain characteristics with time-order-error, assimilation, and temporal partial masking experiments.

  16. Binaural dereverberation based on interaural coherence histograms

    DEFF Research Database (Denmark)

    Westermann, Adam; Buchholz, Jorg M.; Dau, Torsten

    2013-01-01

    A binaural dereverberation algorithm is presented that utilizes the properties of the interaural coherence (IC) inspired by the concepts introduced in Allen et al. [J. Acoust. Soc. Am. 62, 912-915 (1977)]. The algorithm introduces a non-linear sigmoidal coherence-to-gain mapping that is controlled...... by an online estimate of the present coherence statistics. The algorithm automatically adapts to a given acoustic environment and provides a stronger dereverberation effect than the original method presented in Allen et al. [J. Acoust. Soc. Am. 62, 912-915 (1977)] in most acoustic conditions. The...... Allen et al. were considered as reference systems. The results revealed that the proposed coherence-based approach is most successful in acoustic scenarios that exhibit a significant spread in the coherence distribution where direct sound and reverberation can be segregated. This dereverberation...

  17. Physiological evidence of interpersonal dynamics in a cooperative production task.

    Science.gov (United States)

    Mønster, Dan; Håkonsson, Dorthe Døjbak; Eskildsen, Jacob Kjær; Wallot, Sebastian

    2016-03-15

    Recent research suggests that shared behavioral dynamics during interpersonal interaction are indicative of subjective and objective outcomes of the interaction, such as feelings of rapport and success of performance. The role of shared physiological dynamics to quantify interpersonal interaction, however, has received comparatively little attention. In the present study, we investigate the coordination dynamics of multiple psychophysiological measures and their utility in capturing emotional dynamics in teams. We use data from an experiment where teams of three people built origami boats together in an assembly-line manner while their heart rate, skin conductance, and facial muscle activity were recorded. Our results show that physiological synchrony of skin conductance measures and eletromyographic measures of the corrugator supercilii develops spontaneously among team members during this cooperative production task. Moreover, high team synchrony is found indicative of team cohesion, while low team synchrony is found indicative of a teams' decision to adopt a new behavior across multiple production sessions. We conclude that team-level measures of synchrony offer new and complementary information compared to measures of individual levels of physiological activity. PMID:26773466

  18. Seeing is Believing: Formalising False-Belief Tasks in Dynamic Epistemic Logic

    DEFF Research Database (Denmark)

    Bolander, Thomas

    2014-01-01

    In this paper we show how to formalise false-belief tasks like the Sally-Anne task and the second-order chocolate task in Dynamic Epistemic Logic (DEL). False-belief tasks are used to test the strength of the Theory of Mind (ToM) of humans, that is, a human’s ability to attribute mental states to...

  19. Implante coclear Digisonic SP® Binaural: acesso coronal tunelizado Digisonic SP® Binaural cochlear implant: the coronal tunneled approach

    Directory of Open Access Journals (Sweden)

    Guilherme Machado de Carvalho

    2013-06-01

    Full Text Available O implante coclear é um grande avanço no tratamento da surdez. Há grandes evidências que a audição bilateral traz diversas vantagens ao ser humano e muito mais quando se trata de audição binaural. OBJETIVO: Este artigo tem por objetivo descrever o primeiro caso operado no Brasil, sendo o terceiro país das Américas (México e Colômbia a realizar, com implante binaural Neurelec Digisonic SP® demonstrando a técnica cirúrgica. MÉTODO: Descrição da técnica cirúrgica. RESULTADOS: Ver técnica cirúrgica. Procedimento ocorreu sem intercorrências. DISCUSSÃO: O efeito "squelch", a somação binaural, a localização da fonte sonora e o efeito sombra da cabeça são umas das principais razões que justificam a superioridade da reabilitação binaural. O custo do tratamento deve ser levado em conta em políticas de saúde pública. CONCLUSÃO: Custo do implante coclear é um dos grandes limitadores da bilateralidade na reabilitação desse grupo de pacientes, porém, com essa tecnologia, é possível solucionar esse problema, expondo o paciente a poucos riscos, com o uso de uma técnica cirúrgica pouco invasiva.Cochlear implants represent a significant breakthrough in the treatment of hearing loss. Evidence indicates bilateral hearing brings significant benefits to patients, particularly when binaural hearing is offered. OBJECTIVE: To describe the first case of implantation of a Digisonic SP® Binaural Neurelec device in Brazil (the third implant placed in the Americas, after Mexico and Colombia and the chosen surgical approach. METHOD: Description of a surgical approach. RESULTS: The procedure was successfully completed. DISCUSSION: The squelch effect, binaural summation, location of the sound source, and the shadow effect of the head are listed among the reasons to explain the superiority of binaural rehabilitation. Cost of treatment must be considered in the development of public health policies. CONCLUSION: The cost of cochlear

  20. A systematic study of binaural reproduction systems through loudspeakers

    DEFF Research Database (Denmark)

    Lacouture Parodi, Yesenia

    This Ph.D. thesis presents an investigation of the acoustical and psycho-acoustical characteristics of binaural reproduction systems through loudspeakers. The study was mainly focused on the characteristics of closely spaced loudspeakers – known as stereo-dipoles – when placed at different...... positions, e.g. in front of, above or in the back of the head. The main objective of this study is to set foundations for the design of a binaural reproduction system that is robust to head rotations and reduces front-back confusions. Different crosstalk cancellation techniques were investigated and their...... when the loudspeakers are placed above the head and that closely spaced loudspeakers are more robust to lateral displacements than wider span angles. Based on the results obtained from those experiments, a binaural reproduction system that uses three stereo-dipoles is proposed: one pair in front, on...

  1. Calibration aspects of binaural sound reproduction over insert earphones

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.; Markovic, Milos; Olesen, Søren Krarup; Madsen, Esben; Hammershøi, Dorte

    Earphones are nowadays widely adopted for the reproduction of audio material in mobile multimedia and communication platforms, e.g. smartphones. Reproduction of high-quality spatial sound on such platforms can dramatically improve their applicability, and since two channels are always available in...... earphone-based reproduction, binaural reproduction can be applied directly. This paper is concerned with the theoretical and practical aspects relevant to the correct reproduction of binaural signals over insert earphones. To this purpose, a theoretical model originally developed to explain the acoustic...

  2. Acceptability of binaural hearing aids: a cross-over study.

    OpenAIRE

    Stephens, S D; Callaghan, D E; Hogan, S.; Meredith, R.; Rayment, A; Davis, A

    1991-01-01

    Using screening questionnaires we were able to detect individuals aged 50-65 years with hearing disability in a general practice population. Those who had better ear hearing levels of 30 dB or worse were invited to take place in a cross-over study comparing the acceptability of a monaural or binaural hearing-aid fitting. Fifty-five per cent ultimately opted for a binaural fitting and had greater hearing disability and worse mean hearing levels than those who opted for a monaural fitting. They...

  3. Binaural pitch perception in normal-hearing and hearing-impaired listeners

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten

    2007-01-01

    pitches. For the normal-hearing listeners, all types of binaural pitches could be perceived immediately and were musical. The hearing-impaired listeners could be divided into three groups based on their results: (a) some perceived all types of binaural pitches, but with decreased salience or musicality......The effects of hearing impairment on the perception of binaural-pitch stimuli were investigated. Several experiments were performed with normal-hearing and hearing-impaired listeners, including detection and discrimination of binaural pitch, and melody recognition using different types of binaural...... compared to normal-hearing listeners; (b) some could only perceive the strongest pitch types; (c) some were unable to perceive any binaural pitch at all. The performance of the listeners was not correlated with audibility. Additional experiments investigated the correlation between performance in binaural...

  4. Effects of a standing and three dynamic workstations on computer task performance and cognitive function tests

    NARCIS (Netherlands)

    Commissaris, D.A.C.M.; Könemann, R.; Hiemstra-van Mastrigt, S.; Burford, E.M.; Botter, J.; Douwes, M.; Ellegast, R.P.

    2014-01-01

    Sedentary work entails health risks. Dynamic (or active) workstations, at which computer tasks can be combined with physical activity, may reduce the risks of sedentary behaviour. The aim of this study was to evaluate short term task performance while working on three dynamic workstations: a treadmi

  5. The developmental dynamics of task-avoidant behavior and math performance in kindergarten and elementary school

    OpenAIRE

    Hirvonen, Riikka; Tolvanen, Asko; Aunola, Kaisa; Nurmi, Jari-Erik

    2012-01-01

    Besides cognitive factors, children's learning at school may be influenced by more dynamic phenomena, such as motivation and achievement-related task-avoidant behavior. The present study examined the developmental dynamics of task-avoidant behavior and math performance from kindergarten to Grade 4. A total of 225 children were tested for their arithmetic skills in kindergarten and in Grades 1, 2, and 4 of elementary school. Children's task-avoidant behavior in learning situations was rated by...

  6. The effects on dynamic balance of dual-tasking using smartphone functions

    OpenAIRE

    Hyong, In Hyouk

    2015-01-01

    [Purpose] This study aimed to compare dynamic balance with respect to completing a single task while not using smartrphone function and completing two task while using different smartphone functions, therby preventing falls or injuries resulting from completion of dual tasks. [Subjects and Methods] The subjects of this study were 36 healthy males and females. The experiment was conducted for five situations: a Star Excursion Balance Test (SEBT) was performed (1) during single-tasking without ...

  7. Dynamic Task Scheduling Algorithm based on Ant Colony Scheme

    Directory of Open Access Journals (Sweden)

    Kamolov Nizomiddin Baxodirjonovich

    2015-08-01

    Full Text Available Many scientific applications running in Cloud Computing system are workflow applications that contains large number of tasks and in which tasks are connected by precedence relations. Efficient scheduling the workflow tasks become a challenging issue in Cloud Computing environments because the scheduling decides performance of the applications. Unfortunately, finding the optimal scheduling is known as NP-hard. Ant Colony Optimization algorithm can be applied to design efficient scheduling algorithms. Previous scheduling algorithms that use Ant Colony mechanism lack rapid adaptivity. This paper proposes a task scheduling algorithm that uses a modified Ant Colony Optimization. The modified version uses probability in order for ants to decide target machine. The proposed task scheduling algorithm is implemented in WorkflowSim in order to measure performance. The experimental results show that the proposed scheduling algorithm reduce average makespan to about 6.4% compared to a scheduling algorithm that uses basic Ant Colony Optimization scheme.

  8. Binaural technology for e.g. rendering auditory virtual environments

    DEFF Research Database (Denmark)

    Hammershøi, Dorte

    2008-01-01

    acknowledge his efforts in understanding the binaural hearing and the significance of inter-aural differences, appreciation is also in place for his evaluation of localization with identical ear input signals. The relations between the hearing's "directional" bands and the transfer functions‘ "boosted" bands...

  9. Efficiency of brainwave entrainment by binaural beats in reducing anxiety

    Directory of Open Access Journals (Sweden)

    Ahmad Alipoor

    2014-04-01

    Full Text Available Background: Anxiety is a fundamental phenomenon that is a common symptom in all mental disorders. The aim of the present study was to assess the effect of brainwave entrainment on anxiety reduction using binaural beats. Methods: In this experimental double-blind study, 30 employees were selected from an engineering research firm through random sampling and replacement and divided into two groups: control group and experimental group. All participants completed the Spielberger’s State-Trait Anxiety Inventory (STAI. Then, the experimental group listened to binaural beats which was recorded on a non-vocal piece of music for 4 weeks, 3 sessions each week. Each session lasted about 20 minutes. At the same time, the control group listened to the background music without any entrainment sound. At the end, both groups completed the anxiety questionnaire and the anxiety scores of both groups obtained before and after intervention were analyzed by ANCOVA. Results: The findings showed that the brainwave entrainment using binaural beats led to the significant reduction of state anxiety (P<0.001 and trait anxiety (P<0.018. Conclusion: Brainwave entrainment using binaural beats is an effective factor in decreasing state and trait anxiety; so, it can be used to reduce anxiety in mental health centers.

  10. A Heart for Interaction: Shared Physiological Dynamics and Behavioral Coordination in a Collective, Creative Construction Task

    OpenAIRE

    Fusaroli, Riccardo; Bjørndahl, Johanne S.; Roepstorff, Andreas; Tylén, Kristian

    2015-01-01

    Interpersonally shared physiological dynamics are increasingly argued to underlie rapport, empathy and even team performance. Inspired by the model of interpersonal synergy, we critically investigate the presence, temporal development, possible mechanisms and impact of shared interpersonal heart rate dynamics during individual and collective creative LEGO construction tasks. In Study 1 we show how shared HR dynamics are driven by a plurality of sources including task constraints and behaviora...

  11. Modeling dynamic tactical behaviors in COMBATXXI using Hierarchical Task Networks

    OpenAIRE

    Donaldson, Michael J.

    2014-01-01

    Approved for public release; distribution is unlimited Defining accurate representations of group behaviors in simulations is an expensive, time-consuming task. One reason for this is that previously produced behaviors are often not reusable within other scenarios or simulations. Using Hierarchical Task Networks (HTNs) to model military behaviors is a promising technique for addressing this problem. HTNs provide a methodology for linking tactical behaviors, and offer a potential system for...

  12. Effects of a standing and three dynamic workstations on computer task performance and cognitive function tests.

    Science.gov (United States)

    Commissaris, Dianne A C M; Könemann, Reinier; Hiemstra-van Mastrigt, Suzanne; Burford, Eva-Maria; Botter, Juliane; Douwes, Marjolein; Ellegast, Rolf P

    2014-11-01

    Sedentary work entails health risks. Dynamic (or active) workstations, at which computer tasks can be combined with physical activity, may reduce the risks of sedentary behaviour. The aim of this study was to evaluate short term task performance while working on three dynamic workstations: a treadmill, an elliptical trainer, a bicycle ergometer and a conventional standing workstation. A standard sitting workstation served as control condition. Fifteen Dutch adults performed five standardised but common office tasks in an office-like laboratory setting. Both objective and perceived work performance were measured. With the exception of high precision mouse tasks, short term work performance was not affected by working on a dynamic or a standing workstation. The participant's perception of decreased performance might complicate the acceptance of dynamic workstations, although most participants indicate that they would use a dynamic workstation if available at the workplace. PMID:24951234

  13. Relating the absence of binaural pitch percept to retro-cochlear impairment

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten

    that the salience of binaural pitch was affected by hearing impairment. Specifically, for subjects with a sensorineural impairment, binaural pitch perception was weaker than the normal-hearing average but the pitch sensation was immediately present. In contrast, no binaural pitch sensation at all was......Binaural pitch stimuli, created by introducing an interaural phase difference over a narrow band of otherwise diotic white noise, produce an immediate tonal sensation with a pitch close to the centre of the phase-shifted band. In Santurette and Dau [Hear. Res. 223(1-2):29-47, 2007], it was shown...... cognitive abilities, were obtained in order to investigate the correlation between these outcomes and results from the binaural pitch test. As no spectral cues are provided by binaural pitch stimuli, their perception is expected to heavily depend on the acuity of fine structure coding and the accuracy of...

  14. The dynamics of development on the Dimensional Change Card Sorting task

    NARCIS (Netherlands)

    B.M.C.W. van Bers; I. Visser; T.J.P. van Schijndel; D.J. Mandell; M.E.J. Raijmakers

    2011-01-01

    A widely used paradigm to study cognitive flexibility in preschoolers is the Dimensional Change Card Sorting (DCCS) task. The developmental dynamics of DCCS performance was studied in a cross-sectional design (N = 93, 3 to 5 years of age) using a computerized version of the standard DCCS task. A mod

  15. Binaural loudness summation for speech presented via earphones and loudspeaker with and without visual cuesa)

    OpenAIRE

    Epstein, Michael; Florentine, Mary

    2012-01-01

    Preliminary data [M. Epstein and M. Florentine, Ear. Hear. 30, 234–237 (2009)] obtained using speech stimuli from a visually present talker heard via loudspeakers in a sound-attenuating chamber indicate little difference in loudness when listening with one or two ears (i.e., significantly reduced binaural loudness summation, BLS), which is known as “binaural loudness constancy.” These data challenge current understanding drawn from laboratory measurements that indicate a tone presented binaur...

  16. Auditory cortical processing: Binaural interaction in healthy and ROBO1-deficient subjects

    OpenAIRE

    LamminmÀki, Satu

    2012-01-01

    Two functioning ears provide clear advantages over monaural listening. During natural binaural listening, robust brain-level interaction occurs between the slightly different inputs from the left and the right ear. Binaural interaction requires convergence of inputs from the two ears somewhere in the auditory system, and it therefore relies on midline crossing of auditory pathways, a fundamental property of the mammalian central nervous system. Binaural interaction plays a significant ro...

  17. A High-Density EEG Investigation into Steady State Binaural Beat Stimulation

    OpenAIRE

    Goodin, Peter; Ciorciari, Joseph; Baker, Kate; Carrey, Anne-Marie; Harper, Michelle; Kaufman, Jordy

    2012-01-01

    Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation...

  18. Are binaural recordings needed for subjective and objective annoyance assessment of traffic noise?

    DEFF Research Database (Denmark)

    Rodríguez, Estefanía Cortés; Song, Wookeun; Brunskog, Jonas; Jeong, Cheol-Ho; Poulsen, Torben; Manvell, Douglas

    2011-01-01

    environmental noise than the A-weighted equivalent sound pressure level. This study examined whether the use of binaural recordings of sound events improves the correlation between the objective metrics and the perceived annoyance, particularly for road traffic noise. Metrics based on measurement with a single...... microphone and on binaural sound field recordings have been examined and compared. In order to acquire data for the subjective perception of annoyance, a series of listening tests has been carried out. It is concluded that binaural loudness metrics from binaural recordings are better correlated with the...

  19. Task-related Functional Connectivity Dynamics in a Block-designed Visual Experiment

    Directory of Open Access Journals (Sweden)

    Xin Di

    2015-09-01

    Full Text Available Studying task modulations of brain connectivity using functional magnetic resonance imaging (fMRI is critical to understand brain functions that support cognitive and affective processes. Existing methods such as psychophysiological interaction (PPI and dynamic causal modelling (DCM usually implicitly assume that the connectivity patterns are stable over a block-designed task with identical stimuli. However, this assumption lacks empirical verification on high-temporal resolution fMRI data with reliable data-driven analysis methods. The present study performed a detailed examination of dynamic changes of functional connectivity (FC in a simple block-designed visual checkerboard experiment with a sub-second sampling rate (TR = 0.645 s by estimating time-varying correlation coefficient (TVCC between BOLD responses of different brain regions. We observed reliable task-related FC changes (i.e., FCs were transiently decreased after task onset and went back to the baseline afterward among several visual regions of the bilateral middle occipital gyrus (MOG and the bilateral fusiform gyrus (FuG. Importantly, only the FCs between higher visual regions (MOG and lower visual regions (FuG exhibited such dynamic patterns. The results suggested that simply assuming a sustained FC during a task block may be insufficient to capture distinct task-related FC changes. The investigation of FC dynamics in tasks could improve our understanding of condition shifts and the coordination between different activated brain regions.

  20. Dynamic Multi-objective task scheduling in Cloud Computing based on Modified particle swarm optimization

    Directory of Open Access Journals (Sweden)

    A.I.Awad

    2015-09-01

    Full Text Available Task scheduling is one of the most important research topics in Cloud Computing environment. Dynamic Multi-objective task scheduling in Cloud Computing are proposed by using modified particle swarm optimization. This paper presents efficient allocation of tasks to available virtual machine in user level base on different parameters such as reliability, time, cost and load balancing of virtual machine. Agent used to create dynamic system. We propose mathematical model multi-objective Load Balancing Mutation particle swarm optimization (MLBMPSO to schedule and allocate tasks to resource. MLBMPSO considers two objective functions to minimize round trip time and total cost. Reliability can be achieved in system by getting task failure to allocate and reschedule with available resource based on load of virtual machine. Experimental results demonstrated that MLBMPSO outperformed the other algorithms in time and cost.

  1. Dynamics of task-set carry-over: evidence from eye-movement analyses.

    Science.gov (United States)

    Kikumoto, Atsushi; Hubbard, Jason; Mayr, Ulrich

    2016-06-01

    Trial-to-trial carry-over of task sets (i.e., task-set inertia) is often considered as a primary reason for task-switch costs. Yet, we know little about the dynamics of such carry-over effects, in particular how much they are driven by the most recent trial rather than characterized by a more continuous memory gradient. Using eye-tracking, we examined in a 3-task, switching paradigm whether there is a greater probability of non-target fixations to stimuli associated with the previously relevant attentional set than to those associated with the less-recent set. Indeed, we found strong evidence for more interference (expressed in terms of non-target fixations) from recent than from less-recent tasks and that in particular the interference from pre-switch trials contributed substantially to the overall pattern of response-time switch costs. Moreover, task-set carry-over was dominated by the most-recent trial when subjects could expect task repetitions (with a 33 % switch rate). In comparison, when tasks were selected randomly (with a 66 % switch rate), interference from the most recent trial decreased, whereas interference from less-recent trials increased. In sum, carry-over interference dynamics were characterized both by a gradual recency gradient and expectations about task-transition probabilities. Beyond that, there was little evidence for a unique role of the most-recent trial. PMID:26415999

  2. Monitoring cognitive and emotional processes through pupil and cardiac response during dynamic versus logical task.

    Science.gov (United States)

    Causse, Mickaël; Sénard, Jean-Michel; Démonet, Jean François; Pastor, Josette

    2010-06-01

    The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required; in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task performance and task related psychological stress is often ignored. We compared physiological parameters recorded on 24 healthy subjects facing two neuropsychological tasks: a dynamic task that require problem solving in a world that continually evolves over time and a logical task representative of cognitive processes performed by operators facing everyday problem solving. Results showed that the mean pupil diameter change was higher during the dynamic task; conversely, the heart rate was more elevated during the logical task. Finally, the systolic blood pressure seemed to be strongly sensitive to psychological stress. A better taking into account of the precise influence of a given cognitive activity and both workload and related task-induced psychological stress during task performance is a promising way to better monitor operators in complex working situations to detect mental overload or pejorative stress factor of error. PMID:19816770

  3. Miniature Quad-rotor Dynamics Modeling & Guidance for Vision-based Target Tracking Control Tasks

    OpenAIRE

    Barrientos Cruz, Antonio; Colorado Montaño, Julián

    2009-01-01

    This paper presents the dynamics modeling and the control & guidance architecture for specific target tracking indoors tasks using a miniature quad-rotor. Our objective is to develop a testbed using Matlab for experimentation and simulation of dynamics, control and guidance methods within a strong interplay between the hardware on board and software provisioned.

  4. Effect of dual task type on gait and dynamic stability during stair negotiation at different inclinations.

    Science.gov (United States)

    Madehkhaksar, Forough; Egges, Arjan

    2016-01-01

    Stair gait is a common daily activity with great potential risk for falls. Stairs have varying inclinations and people may perform other tasks concurrently with stair gait. This study investigated dual-task interference in the context of complex gait tasks, such as stair gait at different inclinations, a topic about which little is understood. We examined how secondary cognitive and manual tasks interfere with stair gait when a person concurrently performed tasks at different levels of complexity. Gait kinematic data and secondary task performance measures were obtained from fifteen healthy young males while ascending and descending a four-step staircase at three inclinations (17.7°, 29.4°, and 41.5°) as well as level walking. They performed a cognitive task, 'backward digit recall', a manual task, 'carrying a cup of water' and a combination of the two tasks. Gait performance and dynamic stability were assessed by gait speed and whole body center of mass (COM) range of motion in the medial-lateral direction, respectively. No significant effect of the gait task on the cognitive task performance was observed. In contrast, stair walking adversely affected the performance of the manual task compared to level walking. Overall, more difficult postural and secondary tasks resulted in a decrease in gait speed and variation in COM displacement within normal range. Results suggest that COM displacement and gait alterations might be adopted to enhance the stability, and optimize the secondary task performance while walking under challenging circumstances. Our findings are useful for balance and gait evaluation, and for future falls prediction. PMID:26410477

  5. The effects on dynamic balance of dual-tasking using smartphone functions.

    Science.gov (United States)

    Hyong, In Hyouk

    2015-02-01

    [Purpose] This study aimed to compare dynamic balance with respect to completing a single task while not using smartrphone function and completing two task while using different smartphone functions, therby preventing falls or injuries resulting from completion of dual tasks. [Subjects and Methods] The subjects of this study were 36 healthy males and females. The experiment was conducted for five situations: a Star Excursion Balance Test (SEBT) was performed (1) during single-tasking without a smartphone and during dual-tasking with a smartphone, (2) when listening to music using a smartphone, (3) when sending message using a smartphone, (4) when surfing the web using a smartphone, and (5) when playing a game using a smartphone. The condition were the same for all five experimentes. Random selection was done to prevent learing. All experiments were conducted three times, and the averaged values were used for analysis. The SEBT was performed in three directions: anterior, posterolateral, and posterormedial. In consideration the differences in leg length of the subjects, their actual leg length were measured to be used as percentages. Their leg length was measured from the anterior superior iliac spine of the femur to the medial malleolus. [Results] Compared with single task not done using a smartphone, dynamic balance statistically significantly changed for dual tasks done using a smartphone in all three directions. Dynamic balance decreased in all three directions when playing games, sending messages, web surfing, and listening to music. [Conclusion] Completing two tasks using a smartphone reduced cognitive ability, decreasing dynamic balance. Therefore, performing a single task rather than using the diverse functions of a smartphone while walking or working is considered a factor that can prevent falls and injuries. PMID:25729208

  6. Detection and identification of monaural and binaural pitch contours in dyslexic listeners

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten; Poelmans, Hanne;

    2010-01-01

    found that a majority of dyslexic subjects were unable to hear binaural pitch, the latter obtained a clear response of dyslexic listeners to Huggins’ pitch (HP) (Cramer and Huggins, 1958). The present study clarified whether impaired binaural pitch perception is found in dyslexia. Results from a pitch...

  7. Sound Source Distance Estimation in Rooms based on Statistical Properties of Binaural Signals

    DEFF Research Database (Denmark)

    Georganti, Eleftheria; May, Tobias; van de Par, Steven;

    2013-01-01

    A novel method for the estimation of the distance of a sound source from binaural speech signals is proposed. The method relies on several statistical features extracted from such signals and their binaural cues. Firstly, the standard deviation of the difference of the magnitude spectra of the left...

  8. Office task effects on comfort and body dynamics in five dynamic office chairs

    NARCIS (Netherlands)

    Groenesteijn, L.; Ellegast, R.P.; Keller, K.; Krause, F.; Berger, H.; Looze, M.P.de

    2012-01-01

    In the present study, we investigated the effect of office tasks on posture and movements in field settings, and the comfort rating for chair characteristics and correlation with type of task. The tasks studied were: computer work, telephoning, desk work and conversation. Postures, movements, chair

  9. Dynamic task allocation in multi-hop multimedia wireless sensor networks with low mobility.

    OpenAIRE

    Klaus Moessner; Serdar Vural; Yichao Jin; Alexander Gluhak

    2013-01-01

    This paper presents a task allocation-oriented framework to enable efficient in-network processing and cost-effective multi-hop resource sharing for dynamic multi-hop multimedia wireless sensor networks with low node mobility, e.g., pedestrian speeds. The proposed system incorporates a fast task reallocation algorithm to quickly recover from possible network service disruptions, such as node or link failures. An evolutional self-learning mechanism based on a genetic algorithm continuously ada...

  10. Solar dynamic heat rejection technology. Task 1: System concept development

    Science.gov (United States)

    Gustafson, Eric; Carlson, Albert W.

    1987-01-01

    The results are presented of a concept development study of heat rejection systems for Space Station solar dynamic power systems. The heat rejection concepts are based on recent developments in high thermal transport capacity heat pipe radiators. The thermal performance and weights of each of the heat rejection subsystems is addressed in detail, and critical technologies which require development tests and evaluation for successful demonstration are assessed and identified. Baseline and several alternate heat rejection system configurations and optimum designs are developed for both Brayton and Rankine cycles. The thermal performance, mass properties, assembly requirements, reliability, maintenance requirements and life cycle cost are determined for each configuration. A specific design was then selected for each configuration which represents an optimum design for that configuration. The final recommendations of heat rejection system configuration for either the Brayton or Rankine cycles depend on the priorities established for the evaluation criteria.

  11. Better decision making in complex, dynamic tasks training with human-facilitated interactive learning environments

    CERN Document Server

    Qudrat-Ullah, Hassan

    2015-01-01

    This book describes interactive learning environments (ILEs) and their underlying concepts. It explains how ILEs can be used to improve the decision-making process and how these improvements can be empirically verified. The objective of this book is to enhance our understanding of and to gain insights into the process by which human facilitated ILEs are effectively designed and used in improving users’ decision making in complex, dynamic tasks. This book is divided into four major parts. Part I serves as an introduction to the importance and complexity of decision making in dynamic tasks. Part II provides background material, drawing upon relevant literature, for the development of an integrated process model on the effectiveness of human facilitated ILEs in improving decision making in dynamic tasks. Part III focuses on the design, development, and application of FishBankILE in laboratory experiments to gather empirical evidence for the validity of the process model. Finally, part IV presents a comprehensi...

  12. Setup for demonstrating interactive binaural synthesis for telepresence applications

    DEFF Research Database (Denmark)

    Madsen, Esben; Olesen, Søren Krarup; Markovic, Milos;

    2011-01-01

    this system as well as interfaces to relevant parts of the complete system, including tracking and network streaming. In the demonstration, the Visitor is wearing headphones and a microphone. At the Destination, the two Locals are both wearing a microphone, while the Visitor is represented using a....... The combined system was evaluated by the user experience at the demonstration, with the overall conclusion that interactive binaural synthesis is an important aspect of a fully immersive telepresence application and that we should continue in this direction examining different approaches....

  13. Comparisons between Binaural In-situ Recordings and Auralizations

    DEFF Research Database (Denmark)

    Saher, Konca; Rindel, Jens Holger; Nijs, Lau

    2006-01-01

    The doctoral research of ‘Prediction and Assessment of Acoustical Quality in Living-rooms for People with Intellectual Disabilities’ in Delft University of Technology investigates, among other issues, the applicability and verification of auralization as a quality assessment tool in acoustical...... are discussed. The results indicate that although auralizations and binaural recordings evoke different aural perception auralization is a strong tool to assess the acoustical environment before the space is built. Two commercial programs are used for the auralizations. (ODEON and CATT-Acoustics)...

  14. Principles of modulation processing in monaural vs. binaural hearing

    DEFF Research Database (Denmark)

    Piechowiak, Tobias

    2005-01-01

    channels as a detection cue. Durlach [1] introduced the equalization-cancellation (EC) approach as an across-channel mechanism for explaining BMLD and it was recently used to quantitatively account for many binaural listening experiments. Buus [2] was the first to suggest that an EC-type mechanism could...... also be appropriate to account for CMR. However, it was never tested if such an approach is able to quantitatively predict CMR. The aim of the present study is to introduce an EC type model in monaural modulation processing and to test it with a certain stimulus configuration....

  15. Age-Related Shifts in Brain Activity Dynamics during Task Switching

    OpenAIRE

    Jimura, Koji; Braver, Todd S.

    2009-01-01

    Cognitive aging studies have suggested that older adults show declines in both sustained and transient cognitive control processes. However, previous neuroimaging studies have primarily focused on age-related change in the magnitude, but not temporal dynamics, of brain activity. The present study compared brain activity dynamics in healthy old and young adults during task switching. A mixed blocked/event-related functional magnetic resonance imaging design enabled separation of transient and ...

  16. The effect of cochlear nonlinearities on binaural masking level differences

    DEFF Research Database (Denmark)

    Le Goff, Nicolas; Kohlrausch, Armin

    the difference in BMLD between the symmetric and the two asymmetric conditions is constant, in line with the experimental data. Conclusion A model was proposed to account for the effect of level asymmetry on BMLD. The modeling results suggest that cochlear nonlinearites affect the analysis of binaural......Background The binaural masking level difference (BMLD) has been shown to be constant (10−15dB) for masker spectrum levels from 70dB/Hz down to 30−40dB/Hz and to gradually decrease with lower levels (McFadden, 1968; Hall and Harvey, 1984). The decrease at low levels was larger in an asymmetric...... levels between 50 and -10dB/Hz. The difference in BMLD between the two conditions gradually increased with decreasing masker level from 50 to 20dB/Hz and remained constant between 20 and -10dB/Hz. The proposed model could account for these data. A model analysis suggested that the increase in BMLD...

  17. Binaural cues provide for a release from informational masking.

    Science.gov (United States)

    Tolnai, Sandra; Dolležal, Lena-Vanessa; Klump, Georg M

    2015-10-01

    Informational masking (IM) describes the insensitivity of detecting a change in sound features in a complex acoustical environment when such a change could easily be detected in the absence of distracting sounds. IM occurs because of the similarity between deviant sound and distracting sounds (so-called similarity-based IM) and/or stimulus uncertainty stemming from trial-to-trial variability (so-called uncertainty-based IM). IM can be abolished if similarity-based or uncertainty-based IM are minimized. Here, we modulated similarity-based IM using binaural cues. Standard/deviant tones and distracting tones were presented sequentially, and level-increment thresholds were measured. Deviant tones differed from standard tones by a higher sound level. Distracting tones covered a wide range of levels. Standard/deviant tones and distracting tones were characterized by their interaural time difference (ITD), interaural level difference (ILD), or both ITD and ILD. The larger the ITD or ILD was, the better similarity-based IM was overcome. If both interaural differences were applied to standard/deviant tones, the release from IM was larger than when either interaural difference was used. The results show that binaural cues are potent cues to abolish similarity-based IM and that the auditory system makes use of multiple available cues. PMID:26413722

  18. Learning to Manage Intergroup Dynamics in Changing Task Environments: An Experiential Exercise

    Science.gov (United States)

    Hunsaker, Phillip L.

    2004-01-01

    This article describes an exercise that allows participants to experience the challenges of managing intergroup behavior as an organization's task environment grows and becomes more complex. The article begins with a brief review of models and concepts relating to intergroup dynamics, intergroup conflict, and interventions for effectively managing…

  19. Binaural release from masking with single- and multi-electrode stimulation in children with cochlear implants.

    Science.gov (United States)

    Todd, Ann E; Goupell, Matthew J; Litovsky, Ruth Y

    2016-07-01

    Cochlear implants (CIs) provide children with access to speech information from a young age. Despite bilateral cochlear implantation becoming common, use of spatial cues in free field is smaller than in normal-hearing children. Clinically fit CIs are not synchronized across the ears; thus binaural experiments must utilize research processors that can control binaural cues with precision. Research to date has used single pairs of electrodes, which is insufficient for representing speech. Little is known about how children with bilateral CIs process binaural information with multi-electrode stimulation. Toward the goal of improving binaural unmasking of speech, this study evaluated binaural unmasking with multi- and single-electrode stimulation. Results showed that performance with multi-electrode stimulation was similar to the best performance with single-electrode stimulation. This was similar to the pattern of performance shown by normal-hearing adults when presented an acoustic CI simulation. Diotic and dichotic signal detection thresholds of the children with CIs were similar to those of normal-hearing children listening to a CI simulation. The magnitude of binaural unmasking was not related to whether the children with CIs had good interaural time difference sensitivity. Results support the potential for benefits from binaural hearing and speech unmasking in children with bilateral CIs. PMID:27475132

  20. The window of my eyes: Task disengagement and mental fatigue covary with pupil dynamics.

    Science.gov (United States)

    Hopstaken, Jesper F; van der Linden, Dimitri; Bakker, Arnold B; Kompier, Michiel A J

    2015-09-01

    Although mental fatigue is a complex, multi-facetted state that involves changes in motivation, cognition, and mood, one of its main characteristics is reduced task engagement. Despite its relevance for performance and safety, knowledge about the underlying neurocognitive processes in mental fatigue is still limited. Inspired by the idea that central norepinephrine plays an important role in regulating task engagement, we test a set of predictions that have been derived from recent studies that relate pupil dynamics to the levels of norepinephrine in the brain. Participants worked on a 2-back task for 2h while we used pupil measures to further explore the link between task engagement and the effects of mental fatigue. We hypothesized that baseline pupil diameter and stimulus-evoked pupil dilations decrease with increasing fatigue. Also, because previous studies have shown that the effects of fatigue are reversible by increasing the task rewards, we hypothesized that increasing the task rewards after 2h on the task would restore these pupil measures to pre-fatigue levels. While we did not find a decrease in baseline pupil diameter, we found that increasing mental fatigue coincided with diminished stimulus-evoked pupil dilation. Also, we confirmed that when sufficient rewards were presented to a fatigued individual, the pupil dilations could be restored. This supports the view that motivational factors are important in predicting engagement versus disengagement during fatigue. PMID:26196899

  1. A machine-hearing system exploiting head movements for binaural sound localisation in reverberant conditions

    DEFF Research Database (Denmark)

    May, Tobias; Ma, Ning; Wierstorf, Hagen;

    2015-01-01

    investigated the influence of different head movement strategies on binaural sound localisation. A machine-hearing system that exploits a multi-step head rotation strategy for sound localisation was found to produce the best performance in simulated reverberant acoustic space. This paper also reports the......This paper is concerned with machine localisation of multiple active speech sources in reverberant environments using two (binaural) microphones. Such conditions typically present a problem for ‘classical’ binaural models. Inspired by the human ability to utilise head movements, the current study...

  2. Intelligent robot control using an adaptive critic with a task control center and dynamic database

    Science.gov (United States)

    Hall, E. L.; Ghaffari, M.; Liao, X.; Alhaj Ali, S. M.

    2006-10-01

    The purpose of this paper is to describe the design, development and simulation of a real time controller for an intelligent, vision guided robot. The use of a creative controller that can select its own tasks is demonstrated. This creative controller uses a task control center and dynamic database. The dynamic database stores both global environmental information and local information including the kinematic and dynamic models of the intelligent robot. The kinematic model is very useful for position control and simulations. However, models of the dynamics of the manipulators are needed for tracking control of the robot's motions. Such models are also necessary for sizing the actuators, tuning the controller, and achieving superior performance. Simulations of various control designs are shown. Also, much of the model has also been used for the actual prototype Bearcat Cub mobile robot. This vision guided robot was designed for the Intelligent Ground Vehicle Contest. A novel feature of the proposed approach is that the method is applicable to both robot arm manipulators and robot bases such as wheeled mobile robots. This generality should encourage the development of more mobile robots with manipulator capability since both models can be easily stored in the dynamic database. The multi task controller also permits wide applications. The use of manipulators and mobile bases with a high-level control are potentially useful for space exploration, certain rescue robots, defense robots, and medical robotics aids.

  3. Age-related shifts in brain activity dynamics during task switching.

    Science.gov (United States)

    Jimura, Koji; Braver, Todd S

    2010-06-01

    Cognitive aging studies have suggested that older adults show declines in both sustained and transient cognitive control processes. However, previous neuroimaging studies have primarily focused on age-related change in the magnitude, but not temporal dynamics, of brain activity. The present study compared brain activity dynamics in healthy old and young adults during task switching. A mixed blocked/event-related functional magnetic resonance imaging design enabled separation of transient and sustained neural activity associated with cognitive control. Relative to young adults, older adults exhibited not only decreased sustained activity in the anterior prefrontal cortex (aPFC) during task-switching blocks but also increased transient activity on task-switch trials. Another pattern of age-related shift in dynamics was present in the lateral PFC (lPFC) and posterior parietal cortex (PPC), with younger adults showing a cue-related response during task-switch trials in lPFC and PPC, whereas older adults exhibited switch-related activation during the cue period in PPC only. In all 3 regions, these qualitatively distinct patterns of brain activity predicted qualitatively distinct patterns of behavioral performance across the 2 age groups. Together, these results suggest that older adults may shift from a proactive to reactive cognitive control strategy as a means of retaining relatively preserved behavioral performance in the face of age-related neurocognitive changes. PMID:19805420

  4. Multiple Computing Task Scheduling Method Based on Dynamic Data Replication and Hierarchical Strategy

    Directory of Open Access Journals (Sweden)

    Xiang Zhou

    2014-02-01

    Full Text Available As for the problem of how to carry out task scheduling and data replication effectively in the grid and to reduce task’s execution time, this thesis proposes the task scheduling algorithm and the optimum dynamic data replication algorithm and builds a scheme to effectively combine these two algorithms. First of all, the scheme adopts the ISS algorithm considering the number of tasks waiting queue, the location of task demand data and calculation capacity of site by adopting the method of network structure’s hierarchical scheduling to calculate the cost of comprehensive task with the proper weight efficiency and search out the best compute node area. And then the algorithm of ODHRA is adopted to analyze the data transmission time, memory access latency, waiting copy requests in the queue and the distance between nodes, choose out the best replications location in many copies combined with copy placement and copy management to reduce the file access time. The simulation results show that the proposed scheme compared with other algorithm has better performance in terms of average task execution time. 

  5. Internal representation of task rules by recurrent dynamics: the importance of the diversity of neural responses

    Directory of Open Access Journals (Sweden)

    Xiao-Jing Wang

    2010-10-01

    Full Text Available Neural activity of behaving animals, especially in the prefrontal cortex, is highly heterogeneous, with selective responses to diverse aspects of the executed task. We propose a general model of recurrent neural networks that perform complex rule-based tasks, and we show that the diversity of neuronal responses plays a fundamental role when the behavioral responses are context dependent. Specifically, we found that when the inner mental states encoding the task rules are represented by stable patterns of neural activity (attractors of the neural dynamics, the neurons must be selective for combinations of sensory stimuli and inner mental states. Such mixed selectivity is easily obtained by neurons that connect with random synaptic strengths both to the recurrent network and to neurons encoding sensory inputs. The number of randomly connected neurons needed to solve a task is on average only three times as large as the number of neurons needed in a network designed ad hoc. Moreover, the number of needed neurons grows only linearly with the number of task-relevant events and mental states, provided that each neuron responds to a large proportion of events (dense/distributed coding. A biologically realistic implementation of the model captures several aspects of the activity recorded from monkeys performing context dependent tasks. Our findings explain the importance of the diversity of neural responses and provide us with simple and general principles for designing attractor neural networks that perform complex computation.

  6. Dynamic trajectory of multiple single-unit activity during working memory task in rats

    Directory of Open Access Journals (Sweden)

    Xiaofan eZhang

    2015-09-01

    Full Text Available Working memory plays an important role in complex cognitive tasks. A popular theoretical view is that attracting properties of neuronal dynamics underlie cognitive processing. The question raised here as to how the attracting dynamics evolve in working memory. To address this issue, we investigated the multiple single-unit activity dynamics in rat medial prefrontal cortex (mPFC during a Y-maze working memory task. The approach worked by reconstructing state space from delays of the original single-unit firing rate variables, which were further analyzed using kernel principal component analysis (KPCA. Then the neural trajectories were obtained to visualize the multi¬ple single-unit activity. Furthermore, the maximal Lyapunov exponent (MLE was calculated to quantitatively evaluate the neural trajectories during the working memory task. The results showed that the neuronal activity produced stable and reproducible neural trajectories in the correct trials while showed irregular trajectories in the incorrect trials, which may establish a link between the neurocognitive process and behavioral performance in working memory. The MLEs significantly increased during working memory in the correctly performed trials, indicating an increased divergence of the neural trajectories. In the incorrect trials, the MLEs were nearly 0 and remained unchanged during the task. Taken together, the trial-specific neural trajectory provides an effective way to track the instantaneous state of the neuronal ensemble during the working memory task and offers valuable insights into working memory function. The MLE describes the changes of neural dynamics in working memory and may reflect different neuronal ensemble states in working memory.

  7. Binaural advantages in users of bimodal and bilateral cochlear implant devices

    OpenAIRE

    Kokkinakis, Kostas; Pak, Natalie

    2013-01-01

    This paper investigates to what extent users of bilateral and bimodal fittings should expect to benefit from all three different binaural advantages found to be present in normal-hearing listeners. Head-shadow and binaural squelch are advantages occurring under spatially separated speech and noise, while summation emerges when speech and noise coincide in space. For 14 bilateral or bimodal listeners, speech reception thresholds in the presence of four-talker babble were measured in sound-fiel...

  8. Advantages of Binaural Amplification to Acceptable Noise Level of Directional Hearing Aid Users

    OpenAIRE

    Kim, Ja-Hee; Lee, Jae Hee; Lee, Ho-Ki

    2014-01-01

    Objectives The goal of the present study was to examine whether Acceptable Noise Levels (ANLs) would be lower (greater acceptance of noise) in binaural listening than in monaural listening condition and also whether meaningfulness of background speech noise would affect ANLs for directional microphone hearing aid users. In addition, any relationships between the individual binaural benefits on ANLs and the individuals' demographic information were investigated. Methods Fourteen hearing aid us...

  9. Binaural Unmasking of Multi-channel Stimuli in Bilateral Cochlear Implant Users

    OpenAIRE

    Van Deun, Lieselot; Van Wieringen, Astrid; Francart, Tom; Büchner, Andreas; Lenarz, Thomas; Wouters, Jan

    2011-01-01

    Previous work suggests that bilateral cochlear implant users are sensitive to interaural cues if experimental speech processors are used to preserve accurate interaural information in the electrical stimulation pattern. Binaural unmasking occurs in adults and children when an interaural delay is applied to the envelope of a high-rate pulse train. Nevertheless, for speech perception, binaural unmasking benefits have not been demonstrated consistently, even with coordinated stimulation at both ...

  10. The tuning of human motor response to risk in a dynamic environment task.

    Directory of Open Access Journals (Sweden)

    Amber Dunning

    Full Text Available The role of motor uncertainty in discrete or static space tasks, such as pointing tasks, has been investigated in many experiments. These studies have shown that humans hold an internal representation of intrinsic and extrinsic motor uncertainty and compensate for this variability when planning movement. The aim of this study was to investigate how humans respond to uncertainties during movement execution in a dynamic environment despite indeterminate knowledge of the outcome of actions. Additionally, the role of errors, or lack thereof, in predicting risk was examined. In the experiment, subjects completed a driving simulation game on a two-lane road. The road contained random curves so that subjects were forced to use sensory feedback to complete the task and could not rely only on motor planning. Risk was manipulated by using horizontal perturbations to create the illusion of driving on a bumpy road, thereby imposing motor uncertainty, and altering the cost function of the road. Results suggest continual responsiveness to cost and uncertainty in a dynamic task and provide evidence that subjects avoid risk even in the absence of errors. The results suggest that humans tune their statistical motor behavior based on cost, taking into account probabilities of possible outcomes in response to environmental uncertainty.

  11. Dynamic Task Allocation in Multi-Hop Multimedia Wireless Sensor Networks with Low Mobility

    Directory of Open Access Journals (Sweden)

    Klaus Moessner

    2013-10-01

    Full Text Available This paper presents a task allocation-oriented framework to enable efficient in-network processing and cost-effective multi-hop resource sharing for dynamic multi-hop multimedia wireless sensor networks with low node mobility, e.g., pedestrian speeds. The proposed system incorporates a fast task reallocation algorithm to quickly recover from possible network service disruptions, such as node or link failures. An evolutional self-learning mechanism based on a genetic algorithm continuously adapts the system parameters in order to meet the desired application delay requirements, while also achieving a sufficiently long network lifetime. Since the algorithm runtime incurs considerable time delay while updating task assignments, we introduce an adaptive window size to limit the delay periods and ensure an up-to-date solution based on node mobility patterns and device processing capabilities. To the best of our knowledge, this is the first study that yields multi-objective task allocation in a mobile multi-hop wireless environment under dynamic conditions. Simulations are performed in various settings, and the results show considerable performance improvement in extending network lifetime compared to heuristic mechanisms. Furthermore, the proposed framework provides noticeable reduction in the frequency of missing application deadlines.

  12. Multi-Satellite Scheduling Approach for Dynamic Areal Tasks Triggered by Emergent Disasters

    Science.gov (United States)

    Niu, X. N.; Zhai, X. J.; Tang, H.; Wu, L. X.

    2016-06-01

    The process of satellite mission scheduling, which plays a significant role in rapid response to emergent disasters, e.g. earthquake, is used to allocate the observation resources and execution time to a series of imaging tasks by maximizing one or more objectives while satisfying certain given constraints. In practice, the information obtained of disaster situation changes dynamically, which accordingly leads to the dynamic imaging requirement of users. We propose a satellite scheduling model to address dynamic imaging tasks triggered by emergent disasters. The goal of proposed model is to meet the emergency response requirements so as to make an imaging plan to acquire rapid and effective information of affected area. In the model, the reward of the schedule is maximized. To solve the model, we firstly present a dynamic segmenting algorithm to partition area targets. Then the dynamic heuristic algorithm embedding in a greedy criterion is designed to obtain the optimal solution. To evaluate the model, we conduct experimental simulations in the scene of Wenchuan Earthquake. The results show that the simulated imaging plan can schedule satellites to observe a wider scope of target area. We conclude that our satellite scheduling model can optimize the usage of satellite resources so as to obtain images in disaster response in a more timely and efficient manner.

  13. Static and dynamic posterior cingulate cortex nodal topology of default mode network predicts attention task performance.

    Science.gov (United States)

    Lin, Pan; Yang, Yong; Jovicich, Jorge; De Pisapia, Nicola; Wang, Xiang; Zuo, Chun S; Levitt, James Jonathan

    2016-03-01

    Characterization of the default mode network (DMN) as a complex network of functionally interacting dynamic systems has received great interest for the study of DMN neural mechanisms. In particular, understanding the relationship of intrinsic resting-state DMN brain network with cognitive behaviors is an important issue in healthy cognition and mental disorders. However, it is still unclear how DMN functional connectivity links to cognitive behaviors during resting-state. In this study, we hypothesize that static and dynamic DMN nodal topology is associated with upcoming cognitive task performance. We used graph theory analysis in order to understand better the relationship between the DMN functional connectivity and cognitive behavior during resting-state and task performance. Nodal degree of the DMN was calculated as a metric of network topology. We found that the static and dynamic posterior cingulate cortex (PCC) nodal degree within the DMN was associated with task performance (Reaction Time). Our results show that the core node PCC nodal degree within the DMN was significantly correlated with reaction time, which suggests that the PCC plays a key role in supporting cognitive function. PMID:25904156

  14. Task 7a: Dynamic analysis of Paks NPP structures reactor building

    International Nuclear Information System (INIS)

    This report describes dynamic response calculation of the NPP Paks, reactor building to the full scale blast testing. All calculations described in this report have been elaborated within the scope of IAEA co-ordinated research - Benchmark Study for for seismic analysis/testing of NPPs type WWER - Task 7a - Dynamic Analysis of PAKS NPP structures, i.e. reactor building. The input in the form of time history of velocities or accelerations on the free field caused by blast testing was only available for the participants of the task No.7a. The aim of this task is to calculate the dynamic response to the blast load in the form of floor response spectra in selected nodes of the structure without knowing the measured data. The data measured by the full scale blast test are published and the results of different calculations compared. The following structures were taken into account: turbine hall, intermediate multi-storey building, lateral multi-storey building, reactor building, ventilation center and condenser towers

  15. Binaural Fusion and Listening Effort in Children Who Use Bilateral Cochlear Implants: A Psychoacoustic and Pupillometric Study

    OpenAIRE

    Steel, Morrison M.; Papsin, Blake C.; Karen A Gordon

    2015-01-01

    Bilateral cochlear implants aim to provide hearing to both ears for children who are deaf and promote binaural/spatial hearing. Benefits are limited by mismatched devices and unilaterally-driven development which could compromise the normal integration of left and right ear input. We thus asked whether children hear a fused image (ie. 1 vs 2 sounds) from their bilateral implants and if this "binaural fusion" reduces listening effort. Binaural fusion was assessed by asking 25 deaf children wit...

  16. Binaural Hearing and Lateralisation: the Perception of Interaural Differences of Amplitude and Time.

    Science.gov (United States)

    Shackleton, Trevor Maxwell

    Available from UMI in association with The British Library. The perception of the direction of a sound source in the horizontal plane is largely dependent upon the relative arrival times of salient points in the waveform and upon the difference in amplitude at the two ears. Other effects such as binaural release from masking are mediated mainly by the percept of lateralisation. In an extensive literature review the major experiments in binaural unmasking, discrimination and lateralisation are introduced and the most influential binaural detection and lateralisation models discussed. It is argued that these models are all cross-correlation mechanisms operating upon the differences between the firing patterns of the two auditory nerves. A study of the response of the binaural system to changes in its input would be a critical test of such models, so an experiment to measure the threshold of a static tone in noise with temporally varying interaural phase was performed. The results suggest that binaural processing is slow. The extent of lateralisation of bandpass (10%) filtered clicks of both low and high frequencies was studied with various interaural time and amplitude differences. A novel feature of the research, apart from the scaling technique used, was that subjects were encouraged to listen for multiple images. These experiments are sensitive to the breakdown of sensory fusion, and so pose a severe test for binaural models. Very similar results at both low- (250 Hz) and high- (8000 Hz) frequencies suggest a common lateralisation mechanism operating primarily upon interaural onset time differences. A binaural model is proposed which extends existing cross-correlation models. Included is an auditory nerve model which adapts and saturates. The other new element is coincidence detectors with significant (1 ms) integration times, which more closely represent the temporal integration properties of real neural networks. The inclusion of the auditory nerve model is very

  17. 一种基于PVM的主动的任务动态调度策略%A PVM-Based Active Dynamic Task Scheduling Strategy

    Institute of Scientific and Technical Information of China (English)

    朱世进; 李毅; 周明天; 王月

    2000-01-01

    This paper introduces a new PVM-based active dynamic task schcduling strategy. This strategy makes node machine to play an active role in task scheduling. In this way,task scheduling can take full account of loading of node machine and distribute tasks according to this strategy. So we can fulfill load balancing for system and avoid extra burden due to task migration.

  18. Dynamic Scheduling of Skippable Periodic Tasks With Energy Efficiency In Weakly Hard Real-Time System

    Directory of Open Access Journals (Sweden)

    Santhi Baskaran

    2010-12-01

    Full Text Available Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling (DVS allows a processor to dynamically change speed and voltage at run time, thereby saving energy by spreading run cycles into idle time.Knowing when to use full power and when not, requires the cooperation of the operating system scheduler. Usually, higher processor voltage and frequency leads to higher system throughput whileenergy reduction can be obtained using lower voltage and frequency. Instead of lowering processorvoltage and frequency as much as possible, energy efficient real-time scheduling adjusts voltage andfrequency according to some optimization criteria, such as low energy consumption or high throughput,while it meets the timing constraints of the real-time tasks. As the quantity and functional complexity ofbattery powered portable devices continues to raise, energy efficient design of such devices has becomeincreasingly important. Many real-time scheduling algorithms have been developed recently to reduceenergy consumption in the portable devices that use DVS capable processors. Extensive power awarescheduling techniques have been published for energy reduction, but most of them have been focusedsolely on reducing the processor energy consumption. While the processor is one of the major powerhungry units in the system, other peripherals such as network interface card, memory banks, disks alsoconsume significant amount of power. Dynamic Power Down (DPD technique is used to reduce energyconsumption by shutting down the processing unit and peripheral devices, when the system is idle. Threealgorithms namely Red Tasks Only (RTO, Blue When Possible (BWP and Red as Late as Possible (RLPare proposed in the literature to schedule the real-time tasks in Weakly-hard real

  19. Selecting a Dynamic Simulation Modeling Method for Health Care Delivery Research—Part 2: Report of the ISPOR Dynamic Simulation Modeling Emerging Good Practices Task Force

    NARCIS (Netherlands)

    Marshall, Deborah A.; Burgos-Liz, Lina; IJzerman, M.J.; Crown, William; Padula, William V.; Wong, Peter K.; Pasupathy, Kalyan S.; Higashi, Mitchell K.; Osgood, Nathaniel D.

    2015-01-01

    In a previous report, the ISPOR Task Force on Dynamic Simulation Modeling Applications in Health Care Delivery Research Emerging Good Practices introduced the fundamentals of dynamic simulation modeling and identified the types of health care delivery problems for which dynamic simulation modeling c

  20. Numerical simulation of gas dynamics and heat exchange tasks in fuel assemblies of the nuclear reactors

    International Nuclear Information System (INIS)

    This report presents a PC-based program for solution gas dynamics and heat exchange mathematical tasks in fuel assemblies of the fast-neutron nuclear reactors. A fuel assembly consisting of bulk heat-generating elements, which are integrated together by the system of supply and pressure manifolds, is examined. Spherical heat-generating microelements, which contain nuclear fuel, are pulled into the heat-generating elements. Gaseous coolant proceed from supply manifolds to heat-generating elements, where it withdraws the nuclear reaction heat and assembles in pressure manifolds

  1. Subjective diffuseness of music signals convolved with binaural impulse responses

    Science.gov (United States)

    Shimokura, Ryota; Tronchin, Lamberto; Cocchi, Alessandro; Soeta, Yoshiharu

    2011-07-01

    The spatial impression of sound in a hall can be quantified using sound field factors such as the interaural cross-correlation coefficient (IACC) calculated from binaural impulse response (BIR), henceforth denoted by IACC IR. The subjective diffuseness for the listener is a spatial attribute which depends on factors associated both with the source signal and with the actual sound field, and is quantified using the IACC of the signal received by the listener, henceforth denoted by IACC SR. Therefore, the subjective diffuseness in a given hall may change with the music. The aims of this study are to estimate the IACC SR from the IACC IR and the factors, which is obtained from autocorrelation function (ACF) of music signal, and to evaluate the subjective diffuseness by these factors. First, the relationship between the IACC IR and IACC SR was investigated. Second, subjective diffuseness was measured by a psycho-acoustical experiment. As a result, the IACC SR could be estimated from the IACC IR of the BIR and the effective duration ( τe) from the ACF of music signal. It was found that the effects of BIRs on subjective diffuseness could be evaluated by IACC IR for almost all subjects, while the effects of music signals could be evaluated by the τe and the width of the peak at τ=0 ( Wϕ(0) ) of the ACF.

  2. Capturing blocked-entrance binaural signals from open-entrance recordings

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Hoffmann, Pablo F.; Olesen, Søren Krarup;

    2008-01-01

    Binaural recordings enable us to capture all sound attributes including spatial information, room effect, and source characteristics in a given environment. It has been shown that blocked-entrance binaural recordings provide advantages over open-entrance recordings, primarily because the blocked-...... context. To this purpose, equalization filters are derived from the ratio between blocked and open ear canal transfer functions. Different transfer-function measuring techniques and inverse filtering methods are evaluated.......Binaural recordings enable us to capture all sound attributes including spatial information, room effect, and source characteristics in a given environment. It has been shown that blocked-entrance binaural recordings provide advantages over open-entrance recordings, primarily because the blocked......-entrance recordings is not influenced by the ear canal acoustics of the individual for which it is recorded. However, blocking the ear canal for recoding imposes an obvious disruption to normal hearing conditions, which may be unacceptable for applications in which binaural audio capturing is desired but without...

  3. Dynamic Scheduling of Skippable Periodic Tasks with Energy Efficiency in Weakly Hard Real-Time System

    CERN Document Server

    Baskaran, Santhi

    2010-01-01

    Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling (DVS) allows a processor to dynamically change speed and voltage at run time, thereby saving energy by spreading run cycles into idle time. Knowing when to use full power and when not, requires the cooperation of the operating system scheduler. Usually, higher processor voltage and frequency leads to higher system throughput while energy reduction can be obtained using lower voltage and frequency. Instead of lowering processor voltage and frequency as much as possible, energy efficient real-time scheduling adjusts voltage and frequency according to some optimization criteria, such as low energy consumption or high throughput, while it meets the timing constraints of the real-time tasks. As the quantity and functional complexity of battery powered porta...

  4. Identifying the processes underpinning anticipation and decision-making in a dynamic time-constrained task.

    Science.gov (United States)

    Roca, André; Ford, Paul R; McRobert, Allistair P; Mark Williams, A

    2011-08-01

    A novel, representative task was used to examine skill-based differences in the perceptual and cognitive processes underlying performance on a dynamic, externally paced task. Skilled and less skilled soccer players were required to move and interact with life-size, action sequences involving 11 versus 11 soccer situations filmed from the perspective of a central defender in soccer. The ability of participants to anticipate the intentions of their opponents and to make decisions about how they should respond was measured across two separate experiments. In Experiment 1, visual search behaviors were examined using an eye-movement registration system. In Experiment 2, retrospective verbal reports of thinking were gathered from a new sample of skilled and less skilled participants. Skilled participants were more accurate than less skilled participants at anticipating the intentions of opponents and in deciding on an appropriate course of action. The skilled players employed a search strategy involving more fixations of shorter duration in a different sequential order and toward more disparate and informative locations in the display when compared with the less skilled counterparts. The skilled players generated a greater number of verbal report statements with a higher proportion of evaluation, prediction, and planning statements than the less skilled players, suggesting they employed more complex domain-specific memory representations to solve the task. Theoretical, methodological, and practical implications are discussed. PMID:21305386

  5. Aging and the complexity of center of pressure in static and dynamic postural tasks.

    Science.gov (United States)

    Ko, Ji-Hyun; Newell, Karl M

    2016-01-01

    The experiment was set-up to investigate the hypothesis that there is an age-related bi-directional change in complexity of the center of pressure (COP) depending on postural task demands. Healthy young (19-28 year) and old (65-74 year) adults were instructed to match, in two 25s trials for each condition, the COP with constant and sine-wave targets at 2 levels (5 and 40%) of the maximal COP distance (MCD). The root mean square error of COP increased with aging in both MCD levels and tasks. Multi-scale entropy (MSE) and detrended fluctuation analysis showed that the complexity of COP in the old adults was lower compared to the young in the constant target, whereas it was higher in the sine-wave target. The task dependent age-related bi-directional change of COP complexity is counter to the hypothesis of a universal loss of complexity with aging but shows that there is loss of adaptive change in complexity driven by the COP dynamics. PMID:26549788

  6. Dynamic and task-dependent encoding of speech and voice by phase reorganization of cortical oscillations.

    Science.gov (United States)

    Bonte, Milene; Valente, Giancarlo; Formisano, Elia

    2009-02-11

    Speech and vocal sounds are at the core of human communication. Cortical processing of these sounds critically depends on behavioral demands. However, the neurocomputational mechanisms enabling this adaptive processing remain elusive. Here we examine the task-dependent reorganization of electroencephalographic responses to natural speech sounds (vowels /a/, /i/, /u/) spoken by three speakers (two female, one male) while listeners perform a one-back task on either vowel or speaker identity. We show that dynamic changes of sound-evoked responses and phase patterns of cortical oscillations in the alpha band (8-12 Hz) closely reflect the abstraction and analysis of the sounds along the task-relevant dimension. Vowel categorization leads to a significant temporal realignment of responses to the same vowel, e.g., /a/, independent of who pronounced this vowel, whereas speaker categorization leads to a significant temporal realignment of responses to the same speaker, e.g., speaker 1, independent of which vowel she/he pronounced. This transient and goal-dependent realignment of neuronal responses to physically different external events provides a robust cortical coding mechanism for forming and processing abstract representations of auditory (speech) input. PMID:19211877

  7. Binaurality and azimuth tun-ing of neurons in the auditorycortex of the big brown bat

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By using a combined closed and free-field stimulation system, binaurality and azimuth tuning of the neurons in the auditory cortex of the big brown bat, Eptesicus fuscus, were studied. A variety of azimuth-tuning functions were demonstrated for the binaural neurons. The large majority of EE (contralateral and ipsilateral excitatory) neurons exhibited azimuth selectivity with the best azimuths (BA) at contralateral 30(- 40(, some at ipsilateral 20(-40( and preferred azimuth ranges (PAR, response amplitude ≥75% of maximum) between 8( and 40(. Sound source azimuths strongly modulate spike counts with a mean modulation depth of 83.8% for EE neurons. EI (contralateral excitatory and ipsilateral inhibitory) neurons have simple azimuth tuning with BA located at contralateral 20(-40( and a broad PAR ranged from 30( to 55(. The present results suggest that azimuth-tuning characteristics of binaural neurons in the auditory cortex of the bat are of significance for acoustic behaviour.

  8. Sex differences in performance and hemispheric organization for a nonverbal auditory task.

    Science.gov (United States)

    McRoberts, G W; Sanders, B

    1992-02-01

    Musically experienced and inexperienced men and women discriminated among fundamental-frequency contours presented either binaurally (i.e., same contour to both ears) or dichotically (i.e., different contours to each ear). On two separate occasions, males made significantly fewer errors than did females in the binaural condition, but not in the dichotic condition. Subjects with prior musical experience were superior to musically naive subjects in both conditions. The dichotic pitch task produced a left-ear advantage, which was unrelated to gender or musical experience. The results suggest that the male advantage on the binaural task reflects a sex difference in the coordination of the two hemispheres during conjoint processing of the same stimuli rather than a difference in the direction or degree of hemispheric specialization for these stimuli. PMID:1549430

  9. The suppression of scale-free fMRI brain dynamics across three different sources of effort: aging, task novelty and task difficulty.

    Science.gov (United States)

    Churchill, Nathan W; Spring, Robyn; Grady, Cheryl; Cimprich, Bernadine; Askren, Mary K; Reuter-Lorenz, Patricia A; Jung, Mi Sook; Peltier, Scott; Strother, Stephen C; Berman, Marc G

    2016-01-01

    There is growing evidence that fluctuations in brain activity may exhibit scale-free ("fractal") dynamics. Scale-free signals follow a spectral-power curve of the form P(f ) ∝ f(-β), where spectral power decreases in a power-law fashion with increasing frequency. In this study, we demonstrated that fractal scaling of BOLD fMRI signal is consistently suppressed for different sources of cognitive effort. Decreases in the Hurst exponent (H), which quantifies scale-free signal, was related to three different sources of cognitive effort/task engagement: 1) task difficulty, 2) task novelty, and 3) aging effects. These results were consistently observed across multiple datasets and task paradigms. We also demonstrated that estimates of H are robust across a range of time-window sizes. H was also compared to alternative metrics of BOLD variability (SDBOLD) and global connectivity (Gconn), with effort-related decreases in H producing similar decreases in SDBOLD and Gconn. These results indicate a potential global brain phenomenon that unites research from different fields and indicates that fractal scaling may be a highly sensitive metric for indexing cognitive effort/task engagement. PMID:27498696

  10. A Link Loss Model for the On-body Propagation Channel for Binaural Hearing Aids

    OpenAIRE

    Chandra, Rohit; Johansson, Anders J.

    2013-01-01

    Binaural hearing aids communicate with each other through a wireless link for synchronization. A propagation model is needed to estimate the ear-to-ear link loss for such binaural hearing aids. The link loss is a critical parameter in a link budget to decide the sensitivity of the transceiver. In this paper, we have presented a model for the deterministic component of the ear-to-ear link loss. The model takes into account the dominant paths having most of the power of the creeping wave from t...

  11. Inferring reward prediction errors in patients with schizophrenia: a dynamic reward task for reinforcement learning

    Directory of Open Access Journals (Sweden)

    Chia-Tzu eLi

    2014-11-01

    Full Text Available Abnormalities in the dopamine system have long been implicated in explanations of reinforcement learning and psychosis. The updated reward prediction error (RPE—a discrepancy between the predicted and actual rewards—is thought to be encoded by dopaminergic neurons. Dysregulation of dopamine systems could alter the appraisal of stimuli and eventually lead to schizophrenia. Accordingly, the measurement of RPE provides a potential behavioral index for the evaluation of brain dopamine activity and psychotic symptoms. Here, we assess two features potentially crucial to the RPE process, namely belief formation and belief perseveration, via a probability learning task and reinforcement-learning modeling. Forty-five patients with schizophrenia (26 high-psychosis and 19 low-psychosis, based on their p1 and p3 scores in the positive-symptom subscales of the Positive and Negative Syndrome Scale (PANSS and 24 controls were tested in a feedback-based dynamic reward task for their RPE-related decision making. While task scores across the three groups were similar, matching law analysis revealed that the reward sensitivities of both psychosis groups were lower than that of controls. Trial-by-trial data were further fit with a reinforcement learning model using the Bayesian estimation approach. Model fitting results indicated that both psychosis groups tend to update their reward values more rapidly than controls. Moreover, among the three groups, high-psychosis patients had the lowest degree of choice perseveration. Lumping patients’ data together, we also found that patients’ perseveration appears to be negatively correlated (p = .09, trending towards significance with their PANSS p1+p3 scores. Our method provides an alternative for investigating reward-related learning and decision making in basic and clinical settings.

  12. Detection and identification of monaural and binaural pitch contours in dyslexic listeners

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Poelmans, Hanne; Luts, Heleen;

    2010-01-01

    dyslexic listeners to Huggins' pitch (HP). The present study clarified whether impaired binaural pitch perception is found in dyslexia. Results from a pitch contour identification test, performed in 31 dyslexic listeners and 31 matched controls, clearly showed that dyslexics perceived HP as well as the...

  13. A subjective evaluation of the minimum channel separation for reproducing binaural signals over loudspeakers

    DEFF Research Database (Denmark)

    Lacouture Parodi, Yesenia; Rubak, Per

    2011-01-01

    While there are a variety of methods and tradeoffs for creating the necessary crosstalk cancellation when reproducing a binaural signal through loudspeakers in a real environment, there are no studies that reveal the minimum required crosstalk. In the current study the authors simulated varying d...

  14. Using task dynamics to quantify the affordances of throwing for long distance and accuracy.

    Science.gov (United States)

    Wilson, Andrew D; Weightman, Andrew; Bingham, Geoffrey P; Zhu, Qin

    2016-07-01

    In 2 experiments, the current study explored how affordances structure throwing for long distance and accuracy. In Experiment 1, 10 expert throwers (from baseball, softball, and cricket) threw regulation tennis balls to hit a vertically oriented 4 ft × 4 ft target placed at each of 9 locations (3 distances × 3 heights). We measured their release parameters (angle, speed, and height) and showed that they scaled their throws in response to changes in the target's location. We then simulated the projectile motion of the ball and identified a continuous subspace of release parameters that produce hits to each target location. Each subspace describes the affordance of our target to be hit by a tennis ball moving in a projectile motion to the relevant location. The simulated affordance spaces showed how the release parameter combinations required for hits changed with changes in the target location. The experts tracked these changes in their performance and were successful in hitting the targets. We next tested unusual (horizontal) targets that generated correspondingly different affordance subspaces to determine whether the experts would track the affordance to generate successful hits. Do the experts perceive the affordance? They do. In Experiment 2, 5 cricketers threw to hit either vertically or horizontally oriented targets and successfully hit both, exhibiting release parameters located within the requisite affordance subspaces. We advocate a task dynamical approach to the study of affordances as properties of objects and events in the context of tasks as the future of research in this area. (PsycINFO Database Record PMID:26766510

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

    DEFF Research Database (Denmark)

    Malling, Anne Sofie Bøgh; Jensen, Bente Rona

    2016-01-01

    , the aim was to study the effect of motor intensive training performed in a safe anti-gravity environment using lower-body positive pressure (LBPP) technology on performance during dynamic balance related tasks. Thirteen male PDP went through an 8-week control period followed by 8 weeks of motor...

  16. Individual differences and workload effects on strategy adoption in a dynamic task.

    Science.gov (United States)

    Moon, Jungaa; Betts, Shawn; Anderson, John R

    2013-09-01

    The current study investigated the effects of individual differences and workload on strategy adaptivity in a complex, dynamic task called the Space Fortress game (Donchin, 1989). Participants learned to use a strategy of flying a ship in circles around the fortress in a standard game environment. Once they mastered the strategy, they were assigned to different workload conditions and transferred to a nonstandard environment in which a strong wind was introduced that made it more difficult to achieve a circular orbit. About half of the participants continued with their prior circular strategy while the rest adopted a novel strategy that achieved comparable performance with less effort. With this novel strategy, rather than trying to complete orbits they flew into the wind and then allowed the wind to blow them back to achieve a pendulum-like path. Participants without a working-memory load were more likely to adopt the new strategy. Participants were also more likely to adopt the new strategy if their pattern of behavior exposed them more often to the potential of drifting with the wind. The results indicate that spontaneous changes in strategy occur when people are exposed to the potential of a new strategy and have the cognitive resources to understand its potential. PMID:23831665

  17. Biomechanical loading of the shoulder complex and lumbosacral joints during dynamic cart pushing task.

    Science.gov (United States)

    Nimbarte, Ashish D; Sun, Yun; Jaridi, Majid; Hsiao, Hongwei

    2013-09-01

    The primary objective of this study was to quantify the effect of dynamic cart pushing exertions on the biomechanical loading of shoulder and low back. Ten participants performed cart pushing tasks on flat (0°), 5°, and 10° ramped walkways at 20 kg, 30 kg, and 40 kg weight conditions. An optoelectronic motion capturing system configured with two force plates was used for the kinematic and ground reaction force data collection. The experimental data was modeled using AnyBody modeling system to compute three-dimensional peak reaction forces at the shoulder complex (sternoclavicular, acromioclavicular, and glenohumeral) and low back (lumbosacral) joints. The main effect of walkway gradient and cart weight, and gradient by weight interaction on the biomechanical loading of shoulder complex and low back joints was statistically significant (all p distraction loading of glenohumeral joint and inferosuperior loading of the acromioclavicular joint may contribute to the risk of work-related low back and shoulder musculoskeletal disorder with prolonged and repetitive use of carts. PMID:23566675

  18. Binaural fusion and listening effort in children who use bilateral cochlear implants: a psychoacoustic and pupillometric study.

    Directory of Open Access Journals (Sweden)

    Morrison M Steel

    Full Text Available Bilateral cochlear implants aim to provide hearing to both ears for children who are deaf and promote binaural/spatial hearing. Benefits are limited by mismatched devices and unilaterally-driven development which could compromise the normal integration of left and right ear input. We thus asked whether children hear a fused image (ie. 1 vs 2 sounds from their bilateral implants and if this "binaural fusion" reduces listening effort. Binaural fusion was assessed by asking 25 deaf children with cochlear implants and 24 peers with normal hearing whether they heard one or two sounds when listening to bilaterally presented acoustic click-trains/electric pulses (250 Hz trains of 36 ms presented at 1 Hz. Reaction times and pupillary changes were recorded simultaneously to measure listening effort. Bilaterally implanted children heard one image of bilateral input less frequently than normal hearing peers, particularly when intensity levels on each side were balanced. Binaural fusion declined as brainstem asymmetries increased and age at implantation decreased. Children implanted later had access to acoustic input prior to implantation due to progressive deterioration of hearing. Increases in both pupil diameter and reaction time occurred as perception of binaural fusion decreased. Results indicate that, without binaural level cues, children have difficulty fusing input from their bilateral implants to perceive one sound which costs them increased listening effort. Brainstem asymmetries exacerbate this issue. By contrast, later implantation, reflecting longer access to bilateral acoustic hearing, may have supported development of auditory pathways underlying binaural fusion. Improved integration of bilateral cochlear implant signals for children is required to improve their binaural hearing.

  19. A Distributed Cooperative Dynamic Task Planning Algorithm for Multiple Satellites Based on Multi-agent Hybrid Learning

    Institute of Scientific and Technical Information of China (English)

    WANG Chong; LI Jun; JING Ning; WANG Jun; CHEN Hao

    2011-01-01

    Traditionally,heuristic re-planning algorithms are used to tackle the problem of dynamic task planning for multiple satellites.However,the traditional heuristic strategies depend on the concrete tasks,which often affect the result's optimality.Noticing that the historical information of cooperative task planning will impact the latter planning results,we propose a hybrid learning algorithrn for dynamic multi-satellite task planning,which is based on the multi-agent reinforcement learning of policy iteration and the transfer learning.The reinforcement learning strategy of each satellite is described with neural networks.The policy neural network individuals with the best topological structure and weights are found by applying co-evolutionary search iteratively.To avoid the failure of the historical learning caused by the randomly occurring observation requests,a novel approach is proposed to balance the quality and efficiency of the task planning,which converts the historical leaming strategy to the current initial learning strategy by applying the transfer learning algorithm.The simulations and analysis show the feasibility and adaptability of the proposed approach especially for the situation with randomly occurring observation requests.

  20. Dynamically Allocated Hub in Task-Evoked Network Predicts the Vulnerable Prefrontal Locus for Contextual Memory Retrieval in Macaques.

    Directory of Open Access Journals (Sweden)

    Takahiro Osada

    2015-06-01

    Full Text Available Neuroimaging and neurophysiology have revealed that multiple areas in the prefrontal cortex (PFC are activated in a specific memory task, but severity of impairment after PFC lesions is largely different depending on which activated area is damaged. The critical relationship between lesion sites and impairments has not yet been given a clear mechanistic explanation. Although recent works proposed that a whole-brain network contains hubs that play integrative roles in cortical information processing, this framework relying on an anatomy-based structural network cannot account for the vulnerable locus for a specific task, lesioning of which would bring impairment. Here, we hypothesized that (i activated PFC areas dynamically form an ordered network centered at a task-specific "functional hub" and (ii the lesion-effective site corresponds to the "functional hub," but not to a task-invariant "structural hub." To test these hypotheses, we conducted functional magnetic resonance imaging experiments in macaques performing a temporal contextual memory task. We found that the activated areas formed a hierarchical hub-centric network based on task-evoked directed connectivity, differently from the anatomical network reflecting axonal projection patterns. Using a novel simulated-lesion method based on support vector machine, we estimated severity of impairment after lesioning of each area, which accorded well with a known dissociation in contextual memory impairment in macaques (impairment after lesioning in area 9/46d, but not in area 8Ad. The predicted severity of impairment was proportional to the network "hubness" of the virtually lesioned area in the task-evoked directed connectivity network, rather than in the anatomical network known from tracer studies. Our results suggest that PFC areas dynamically and cooperatively shape a functional hub-centric network to reallocate the lesion-effective site depending on the cognitive processes, apart from

  1. Skill biased technical change: panel evidence of task orientation, wage effects, and labor dynamics

    OpenAIRE

    Ross, Matthew

    2014-01-01

    Existing empirical analyses of Skill Biased Technical Change focus on examining repeated cross-sections of individuals holding occupational task measures fixed. That approach cannot explore how wages respond to temporal variation in task orientation. This analysis examines wage effects using a synthetic panel of occupational task measures constructed from 17 releases of the O*NET database. This synthetic panel is combined with a panel of individual workers. Cross-occupational estimates that c...

  2. The CAVA corpus: synchronised stereoscopic and binaural datasets with head movements

    OpenAIRE

    Arnaud, Elise; Christensen, Heidi; Lu, Yan-Chen; Barker, Jon; Khalidov, Vasil; Hansard, Miles; Holveck, Bertrand; Mathieu, Herve; Narasimha, Ramya; Taillant, Elise; Forbes, Florence; Horaud, Radu

    2008-01-01

    International audience This paper describes the acquisition and content of a new multi-modal database. Some tools for making use of the data streams are also presented. The Computational Audio- Visual Analysis (CAVA) database is a unique collection of three synchronised data streams obtained from a binaural microphone pair, a stereoscopic camera pair and a head tracking device. All recordings are made from the perspective of a person; i.e. what would a human with natural head movements see...

  3. Improving speech intelligibility for binaural voice transmission under disturbing noise and reverberation using virtual speaker lateralization

    OpenAIRE

    A.L. Padilla Ortiz; F. Orduña-Bustamante

    2015-01-01

    Subjective speech intelligibility tests were carried out in order to investigate strategies to improve speech intelligibility in binaural voice transmission when listening from different azimuth angles under adverse listening conditions. Phonetically balanced bi-syllable meaningful words in Spanish were used as speech material. The speech signal was played back through headphones, undisturbed, and also with the addition of high levels of disturbing noise or reverberation, with a signal to ...

  4. ROBUST LOCALISATION OF MULTIPLE SPEAKERS EXPLOITING HEAD MOVEMENTS AND MULTI-CONDITIONAL TRAINING OF BINAURAL CUES

    DEFF Research Database (Denmark)

    May, Tobias; Ma, Ning; Brown, Guy

    2015-01-01

    differences (ITDs) and interaural level dif- ferences (ILDs) in the front and rear hemifield, a machine hearing system is presented which combines supervised learning of binaural cues using multi-conditional training (MCT) with a head movement strategy. A systematic evaluation showed that this approach...... substan- tially reduced the amount of front-back confusions in challenging acoustic scenarios. Moreover, the system was able to generalise to a variety of different acoustic conditions not seen during training....

  5. Improvements in speech perception and sound localization in hearing aids using binaural multichannel Wiener filtering

    OpenAIRE

    Van den Bogaert, Tim; Doclo, Simon; Wouters, Jan; Moonen, Marc

    2008-01-01

    Multi-microphone noise reduction algorithms are commonly implemented in modern hearing aids to improve speech intelligibility in noisy environments. The development of these algorithms has mostly focused on monaural systems. The human auditory system is a binaural system which compares and combines the signals received by both ears to perceive and localize a single sound source. Providing two monaural, independently operating, noise reduction systems (a bilateral configuration) to the hearing...

  6. A Link Loss Model for the On-body Propagation Channel for Binaural Hearing Aids

    CERN Document Server

    Chandra, Rohit

    2013-01-01

    Binaural hearing aids communicate with each other through a wireless link for synchronization. A propagation model is needed to estimate the ear-to-ear link loss for such binaural hearing aids. The link loss is a critical parameter in a link budget to decide the sensitivity of the transceiver. In this paper, we have presented a model for the deterministic component of the ear-to-ear link loss. The model takes into account the dominant paths having most of the power of the creeping wave from the transceiver in one ear to the transceiver in other ear and the effect of the protruding part of the outer ear called pinna. Simulations are done to validate the model using in-the-ear (ITE) placement of antennas at 2.45 GHz on two heterogeneous phantoms of different age-group and body size. The model agrees with the simulations. The ear-to-ear link loss between the antennas for the binaural hearing aids in the homogeneous SAM phantom is compared with a heterogeneous phantom. It is found that the absence of the pinna an...

  7. Towards a cognitive robotics methodology for reward-based decision-making: dynamical systems modelling of the Iowa Gambling Task

    Science.gov (United States)

    Lowe, Robert; Ziemke, Tom

    2010-09-01

    The somatic marker hypothesis (SMH) posits that the role of emotions and mental states in decision-making manifests through bodily responses to stimuli of import to the organism's welfare. The Iowa Gambling Task (IGT), proposed by Bechara and Damasio in the mid-1990s, has provided the major source of empirical validation to the role of somatic markers in the service of flexible and cost-effective decision-making in humans. In recent years the IGT has been the subject of much criticism concerning: (1) whether measures of somatic markers reveal that they are important for decision-making as opposed to behaviour preparation; (2) the underlying neural substrate posited as critical to decision-making of the type relevant to the task; and (3) aspects of the methodological approach used, particularly on the canonical version of the task. In this paper, a cognitive robotics methodology is proposed to explore a dynamical systems approach as it applies to the neural computation of reward-based learning and issues concerning embodiment. This approach is particularly relevant in light of a strongly emerging alternative hypothesis to the SMH, the reversal learning hypothesis, which links, behaviourally and neurocomputationally, a number of more or less complex reward-based decision-making tasks, including the 'A-not-B' task - already subject to dynamical systems investigations with a focus on neural activation dynamics. It is also suggested that the cognitive robotics methodology may be used to extend systematically the IGT benchmark to more naturalised, but nevertheless controlled, settings that might better explore the extent to which the SMH, and somatic states per se, impact on complex decision-making.

  8. Novel Modeling of Task vs. Rest Brain State Predictability Using a Dynamic Time Warping Spectrum: Comparisons and Contrasts with Other Standard Measures of Brain Dynamics

    Science.gov (United States)

    Dinov, Martin; Lorenz, Romy; Scott, Gregory; Sharp, David J.; Fagerholm, Erik D.; Leech, Robert

    2016-01-01

    Dynamic time warping, or DTW, is a powerful and domain-general sequence alignment method for computing a similarity measure. Such dynamic programming-based techniques like DTW are now the backbone and driver of most bioinformatics methods and discoveries. In neuroscience it has had far less use, though this has begun to change. We wanted to explore new ways of applying DTW, not simply as a measure with which to cluster or compare similarity between features but in a conceptually different way. We have used DTW to provide a more interpretable spectral description of the data, compared to standard approaches such as the Fourier and related transforms. The DTW approach and standard discrete Fourier transform (DFT) are assessed against benchmark measures of neural dynamics. These include EEG microstates, EEG avalanches, and the sum squared error (SSE) from a multilayer perceptron (MLP) prediction of the EEG time series, and simultaneously acquired FMRI BOLD signal. We explored the relationships between these variables of interest in an EEG-FMRI dataset acquired during a standard cognitive task, which allowed us to explore how DTW differentially performs in different task settings. We found that despite strong correlations between DTW and DFT-spectra, DTW was a better predictor for almost every measure of brain dynamics. Using these DTW measures, we show that predictability is almost always higher in task than in rest states, which is consistent to other theoretical and empirical findings, providing additional evidence for the utility of the DTW approach. PMID:27242502

  9. Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance

    Science.gov (United States)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, "interactive alignment" and "interpersonal synergy", and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy…

  10. Investigating conversational dynamics: Interactive alignment, Interpersonal synergy, and collective task performance

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, interactive alignment and interpersonal synergy, and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between...

  11. Acquisition and production of skilled behavior in dynamic decision-making tasks

    Science.gov (United States)

    Kirlik, Alex

    1992-01-01

    Detailed summaries of two NASA-funded research projects are provided. The first project was an ecological task analysis of the Star Cruiser model. Star Cruiser is a psychological model designed to test a subject's level of cognitive activity. Ecological task analysis is used as a framework to predict the types of cognitive activity required to achieve productive behavior and to suggest how interfaces can be manipulated to alleviate certain types of cognitive demands. The second project is presented in the form of a thesis for the Masters Degree. The thesis discusses the modeling of decision-making through the use of neural network and genetic-algorithm machine learning technologies.

  12. A Heart for Interaction: Shared Physiological Dynamics and Behavioral Coordination in a Collective, Creative Construction Task

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Stege Bjørndahl, Johanne; Roepstorff, Andreas;

    2016-01-01

    Interpersonally shared physiological dynamics are increasingly argued to underlie rapport, empathy and even team performance. Inspired by the model of interpersonal synergy, we critically investigate the presence, temporal development, possible mechanisms and impact of shared interpersonal heart ...... in our study, our results warrant not to consider HR dynamics a general driving mechanism of social coordination. Behavioral coordination - on the other hand - seems to be more informative of both shared physiological dynamics and collective experience....

  13. Computer modeling of tasks in dynamics of viscoelastic thin-walled elements in structures of variable thickness

    Directory of Open Access Journals (Sweden)

    R.A. Abdikarimov

    2014-08-01

    Full Text Available The paper presents a numerical method and algorithm for solving tasks in dynamics of viscoelastic thin-walled elements in structures of variable thickness. The equations of motion concerning deflections are described by partial integro-differential equations (PIDE. Using Bubnov-Galerkin’s method, based on the polynomial approximation of deflections, the task is limited to the study of the system of ordinary IDEs, where the independent variable is time. The solution to the system of IDEs is obtained by the offered numerical method, which results into the algorithm of the numerical solution and the program in the Delphi algorithmic language. The study of nonlinear vibrations of thin-walled elements in structures, allowing for variable thickness in the geometrical nonlinear statement, has enabled revealing a number of mechanical effects. Depending on physico-mechanical and geometrical parameters of the considered viscoelastic thin-walled elements in structures, the authors reccommend how to use the rigidity of the system.

  14. A Nonverbal Phoneme Deletion Task Administered in a Dynamic Assessment Format

    Science.gov (United States)

    Gillam, Sandra Laing; Fargo, Jamison; Foley, Beth; Olszewski, Abbie

    2011-01-01

    Purpose: The purpose of the project was to design a nonverbal dynamic assessment of phoneme deletion that may prove useful with individuals who demonstrate complex communication needs (CCN) and are unable to communicate using natural speech or who present with moderate-severe speech impairments. Method: A nonverbal dynamic assessment of phoneme…

  15. A Binaural Cochlear Implant Sound Coding Strategy Inspired by the Contralateral Medial Olivocochlear Reflex

    Science.gov (United States)

    Eustaquio-Martín, Almudena; Stohl, Joshua S.; Wolford, Robert D.; Schatzer, Reinhold; Wilson, Blake S.

    2016-01-01

    Objectives: In natural hearing, cochlear mechanical compression is dynamically adjusted via the efferent medial olivocochlear reflex (MOCR). These adjustments probably help understanding speech in noisy environments and are not available to the users of current cochlear implants (CIs). The aims of the present study are to: (1) present a binaural CI sound processing strategy inspired by the control of cochlear compression provided by the contralateral MOCR in natural hearing; and (2) assess the benefits of the new strategy for understanding speech presented in competition with steady noise with a speech-like spectrum in various spatial configurations of the speech and noise sources. Design: Pairs of CI sound processors (one per ear) were constructed to mimic or not mimic the effects of the contralateral MOCR on compression. For the nonmimicking condition (standard strategy or STD), the two processors in a pair functioned similarly to standard clinical processors (i.e., with fixed back-end compression and independently of each other). When configured to mimic the effects of the MOCR (MOC strategy), the two processors communicated with each other and the amount of back-end compression in a given frequency channel of each processor in the pair decreased/increased dynamically (so that output levels dropped/increased) with increases/decreases in the output energy from the corresponding frequency channel in the contralateral processor. Speech reception thresholds in speech-shaped noise were measured for 3 bilateral CI users and 2 single-sided deaf unilateral CI users. Thresholds were compared for the STD and MOC strategies in unilateral and bilateral listening conditions and for three spatial configurations of the speech and noise sources in simulated free-field conditions: speech and noise sources colocated in front of the listener, speech on the left ear with noise in front of the listener, and speech on the left ear with noise on the right ear. In both bilateral and

  16. 4D time-frequency representation for binaural speech signal processing

    Science.gov (United States)

    Mikhael, Raed; Szu, Harold H.

    2006-04-01

    Hearing is the ability to detect and process auditory information produced by the vibrating hair cilia residing in the corti of the ears to the auditory cortex of the brain via the auditory nerve. The primary and secondary corti of the brain interact with one another to distinguish and correlate the received information by distinguishing the varying spectrum of arriving frequencies. Binaural hearing is nature's way of employing the power inherent in working in pairs to process information, enhance sound perception, and reduce undesired noise. One ear might play a prominent role in sound recognition, while the other reinforces their perceived mutual information. Developing binaural hearing aid devices can be crucial in emulating the working powers of two ears and may be a step closer to significantly alleviating hearing loss of the inner ear. This can be accomplished by combining current speech research to already existing technologies such as RF communication between PDAs and Bluetooth. Ear Level Instrument (ELI) developed by Micro-tech Hearing Instruments and Starkey Laboratories is a good example of a digital bi-directional signal communicating between a PDA/mobile phone and Bluetooth. The agreement and disagreement of arriving auditory information to the Bluetooth device can be classified as sound and noise, respectively. Finding common features of arriving sound using a four coordinate system for sound analysis (four dimensional time-frequency representation), noise can be greatly reduced and hearing aids would become more efficient. Techniques developed by Szu within an Artificial Neural Network (ANN), Blind Source Separation (BSS), Adaptive Wavelets Transform (AWT), and Independent Component Analysis (ICA) hold many possibilities to the improvement of acoustic segmentation of phoneme, all of which will be discussed in this paper. Transmitted and perceived acoustic speech signal will improve, as the binaural hearing aid will emulate two ears in sound

  17. A robust certification service for highly dynamic MANET in emergency tasks

    DEFF Research Database (Denmark)

    Ge, M; Lam, K Y; Gollmann, Dieter;

    2009-01-01

    In emergency tasks, cross-agency operations being carried out in disaster-hit areas require some supporting communication system for command and control. Mobile Ad hoc Network (MANET) is a very suitable way to meet such communication requirements since it can function without any pre-installed co......In emergency tasks, cross-agency operations being carried out in disaster-hit areas require some supporting communication system for command and control. Mobile Ad hoc Network (MANET) is a very suitable way to meet such communication requirements since it can function without any pre......-installed communication infrastructure. Owing to potential threats in the field environment and the unique features of MANET (e.g. the open nature of wireless links and the absence of security infrastructure), security of communications over MANET is a serious issue that is typically addressed by asymmetric cryptographic...

  18. Technical and perceptual issues on head-related transfer functions sets for use in binaural synthesis

    DEFF Research Database (Denmark)

    Toledo, Daniela

    of binaural synthesis in providing a realistic and/or convincing virtual sonic experience relies largely on technical and perceptual issues inherent to the HRTFs and their use, particularly on how well the spectral features of the HRTFs used match those of the listener. This PhD thesis focused on...... identifying the spectral features that cue sound localization in the mid-sagittal plane. Listening tests were conducted from which groups of individual and non-individual HRTFs that evoked the same direction were obtained. Analysis of these HRTFs suggested that the relevant spectral cues covered a broad range...

  19. Blind estimation of the number of speech source in reverberant multisource scenarios based on binaural signals

    DEFF Research Database (Denmark)

    May, Tobias; van de Par, Steven

    2012-01-01

    In this paper we present a new approach for estimating the number of active speech sources in the presence of interfering noise sources and reverberation. First, a binaural front-end is used to detect the spatial positions of all active sound sources, resulting in a binary mask for each candidate...... on a support vector machine (SVM) classifier. A systematic analysis shows that the proposed algorithm is able to blindly determine the number and the corresponding spatial positions of speech sources in multisource scenarios and generalizes well to unknown acoustic conditions...

  20. Monitoring Cognitive and Emotional Processes Through Pupil and Cardiac Response During Dynamic Versus Logical Task

    OpenAIRE

    Causse, Mickael; Senard, Jean-Michel; Démonet, Jean François; Pastor, Josette

    2010-01-01

    The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required; in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task perfo...

  1. Dynamic task-specific brain network connectivity in children with severe reading difficulties

    OpenAIRE

    Vourkas, Michael; Micheloyannis, Sifis; Simos, Panagiotis G.; Rezaie, Roozbeh; Fletcher, Jack M.; Cirino, Paul T.; Andrew C. Papanicolaou

    2010-01-01

    We investigated patterns of sensor-level functional connectivity derived from single-trial whole-head magnetoencephalography data during a pseudoword reading and a letter-sound naming task in children with reading difficulties (RD) and children with no reading impairments (NI). The Phase Lag Index (PLI), a linear and nonlinear estimator, computed for each pair of sensors, was used to construct graphs and obtain estimates of local and global network efficiency according to graph theory. In the...

  2. Movement generation using dynamical systems: a humanoid robot performing a drumming task

    OpenAIRE

    Degallier, Sarah; Santos, Cristina; Righetti, Ludovic; Ijspeert, Auke

    2006-01-01

    The online generation of trajectories in humanoid robots remains a difficult problem. In this contribution, we present a system that allows the superposition, and the switch between, discrete and rhythmic movements. Our approach uses nonlinear dynamical systems for generating trajectories online and in real time. Our goal is to make use of attractor properties of dynamical systems in order to provide robustness against small perturbations and to enable online modulation of the trajector...

  3. ERP correlates of auditory goal-directed behavior of younger and older adults in a dynamic speech perception task.

    Science.gov (United States)

    Getzmann, Stephan; Falkenstein, Michael; Wascher, Edmund

    2015-02-01

    The ability to understand speech under adverse listening conditions deteriorates with age. In addition to genuine hearing deficits, age-related declines in attentional and inhibitory control are assumed to contribute to these difficulties. Here, the impact of task-irrelevant distractors on speech perception was studied in 28 younger and 24 older participants in a simulated "cocktail party" scenario. In a two-alternative forced-choice word discrimination task, the participants responded to a rapid succession of short speech stimuli ("on" and "off") that was presented at a frequent standard location or at a rare deviant location in silence or with a concurrent distractor speaker. Behavioral responses and event-related potentials (mismatch negativity MMN, P3a, and reorienting negativity RON) were analyzed to study the interplay of distraction, orientation, and refocusing in the presence of changes in target location. While shifts in target location decreased performance of both age groups, this effect was more pronounced in the older group. Especially in the distractor condition, the electrophysiological measures indicated a delayed attention capture and a delayed re-focussing of attention toward the task-relevant stimulus feature in the older group, relative to the young group. In sum, the results suggest that a delay in the attention switching mechanism contribute to the age-related difficulties in speech perception in dynamic listening situations with multiple speakers. PMID:25447300

  4. Task and context sensitive optimization of gripper design using dynamic grasp simulation

    DEFF Research Database (Denmark)

    Wolniakowski, Adam; Jørgensen, Jimmy Alison; Miatliuk, Konstantsin;

    2015-01-01

    In this work, we present a generic approach to optimize the design of a parametrized robot gripper including both gripper parameters and parameters of the finger geometry. We demonstrate our gripper optimization on a parallel jaw type gripper which we have parametrized in a 11 dimensional space. We...... furthermore present a parametrization of the grasping task and context, which is essential as input to the computation of gripper performance. We exemplify the feasibility of our approach by computing several optimized grippers on a real world industrial object in three different scenarios....

  5. Hip External Rotator Strength Is Associated With Better Dynamic Control of the Lower Extremity During Landing Tasks.

    Science.gov (United States)

    Malloy, Philip J; Morgan, Alexander M; Meinerz, Carolyn M; Geiser, Christopher F; Kipp, Kristof

    2016-01-01

    The purpose of this study was to determine the association between hip strength and lower extremity kinematics and kinetics during unanticipated single-leg landing and cutting tasks in collegiate female soccer players. Twenty-three National Collegiate Athletic Association division I female soccer players were recruited for strength testing and biomechanical analysis. Maximal isometric hip abduction and external rotation strength were measured using a hand-held dynamometer and expressed as muscle torque (force × femoral length) and normalized to body weight. Three-dimensional lower extremity kinematics and kinetics were assessed with motion analysis and force plates, and an inverse dynamics approach was used to calculate net internal joint moments that were normalized to body weight. Greater hip external rotator strength was significantly associated with greater peak hip external rotation moments (r = 0.47; p = 0.021), greater peak knee internal rotation moments (r = 0.41; p = 0.048), greater hip frontal plane excursion (r = 0.49; p = 0.017), and less knee transverse plane excursion (r = -0.56; p = 0.004) during unanticipated single-leg landing and cutting tasks. In addition, a statistical trend was detected between hip external rotator strength and peak hip frontal plane moments (r = 0.39; p = 0.06). The results suggest that females with greater hip external rotator strength demonstrate better dynamic control of the lower extremity during unanticipated single-leg landing and cutting tasks and provide further support for the link between hip strength and lower extremity landing mechanics. PMID:26110347

  6. Using a binaural biomimetic array to identify bottom objects ensonified by echolocating dolphins

    Science.gov (United States)

    Heiweg, D.A.; Moore, P.W.; Martin, S.W.; Dankiewicz, L.A.

    2006-01-01

    The development of a unique dolphin biomimetic sonar produced data that were used to study signal processing methods for object identification. Echoes from four metallic objects proud on the bottom, and a substrate-only condition, were generated by bottlenose dolphins trained to ensonify the targets in very shallow water. Using the two-element ('binaural') receive array, object echo spectra were collected and submitted for identification to four neural network architectures. Identification accuracy was evaluated over two receive array configurations, and five signal processing schemes. The four neural networks included backpropagation, learning vector quantization, genetic learning and probabilistic network architectures. The processing schemes included four methods that capitalized on the binaural data, plus a monaural benchmark process. All the schemes resulted in above-chance identification accuracy when applied to learning vector quantization and backpropagation. Beam-forming or concatenation of spectra from both receive elements outperformed the monaural benchmark, with higher sensitivity and lower bias. Ultimately, best object identification performance was achieved by the learning vector quantization network supplied with beam-formed data. The advantages of multi-element signal processing for object identification are clearly demonstrated in this development of a first-ever dolphin biomimetic sonar. ?? 2006 IOP Publishing Ltd.

  7. Dynamic Programming for Re-Mapping Noisy Fixations in Translation Tasks

    DEFF Research Database (Denmark)

    Carl, Michael

    2013-01-01

    possible fixated symbols, including those on the line above and below the naïve fixation mapping. In a second step a dynamic programming algorithm applies a number of heuristics to find the best path through the lattice, based on the probable distance in characters, in words and in pixels between...

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

    Science.gov (United States)

    Malling, Anne Sofie B; Jensen, Bente R

    2016-01-01

    Recent studies indicate that the effect of training on motor performance in persons with Parkinson's disease (PDP) is dependent on motor intensity. However, training of high motor intensity can be hard to apply in PDP due to e.g. bradykinesia, rigidity, tremor and postural instability. Therefore, the aim was to study the effect of motor intensive training performed in a safe anti-gravity environment using lower-body positive pressure (LBPP) technology on performance during dynamic balance related tasks. Thirteen male PDP went through an 8-week control period followed by 8 weeks of motor intensive antigravity training. Seventeen healthy males constituted a control group (CON). Performance during a five repetition sit-to-stand test (STS; sagittal plane) and a dynamic postural balance test (DPB; transversal plane) was evaluated. Effect measures were completion time, functional rates of force development, directional changes and force variance. STS completion time improved by 24% to the level of CON which was explained by shorter sitting-time and standing-time and larger numeric rate of force change during lowering to the chair, indicating faster vertical directional change and improved relaxation. DPB completion time tended to improve and was accompanied by improvements of functional medial and lateral rates of force development and higher vertical force variance during DPB. Our results suggest that the performance improvements may relate to improved inter-limb coordination. It is concluded that 8 weeks of motor intensive training in a safe LBPP environment improved performance during dynamic balance related tasks in PDP. PMID:26444077

  9. Dynamic simulation of task constrained of a rigid-flexible manipulator

    Directory of Open Access Journals (Sweden)

    Atef A. Ata

    2008-11-01

    Full Text Available A rigid-flexible manipulator may be assigned tasks in a moving environment where the winds or vibrations affect the position and/or orientation of surface of operation. Consequently, losses of the contact and perhaps degradation of the performance may occur as references are changed. When the environment is moving, knowledge of the angle ? between the contact surface and the horizontal is required at every instant. In this paper, different profiles for the time varying angle ? are proposed to investigate the effect of this change into the contact force and the joint torques of a rigid-flexible manipulator. The coefficients of the equation of the proposed rotating surface are changing with time to determine the new X and Y coordinates of the moving surface as the surface rotates.

  10. A Binaural CI Research Platform for Oticon Medical SP/XP Implants Enabling ITD/ILD and Variable Rate Processing.

    Science.gov (United States)

    Backus, B; Adiloğlu, K; Herzke, T

    2015-01-01

    We present the first portable, binaural, real-time research platform compatible with Oticon Medical SP and XP generation cochlear implants. The platform consists of (a) a pair of behind-the-ear devices, each containing front and rear calibrated microphones, (b) a four-channel USB analog-to-digital converter, (c) real-time PC-based sound processing software called the Master Hearing Aid, and (d) USB-connected hardware and output coils capable of driving two implants simultaneously. The platform is capable of processing signals from the four microphones simultaneously and producing synchronized binaural cochlear implant outputs that drive two (bilaterally implanted) SP or XP implants. Both audio signal preprocessing algorithms (such as binaural beamforming) and novel binaural stimulation strategies (within the implant limitations) can be programmed by researchers. When the whole research platform is combined with Oticon Medical SP implants, interaural electrode timing can be controlled on individual electrodes to within ±1 µs and interaural electrode energy differences can be controlled to within ±2%. Hence, this new platform is particularly well suited to performing experiments related to interaural time differences in combination with interaural level differences in real-time. The platform also supports instantaneously variable stimulation rates and thereby enables investigations such as the effect of changing the stimulation rate on pitch perception. Because the processing can be changed on the fly, researchers can use this platform to study perceptual changes resulting from different processing strategies acutely. PMID:26721923

  11. The across frequency independence of equalization of interaural time delay in the equalization-cancellation model of binaural unmasking

    Science.gov (United States)

    Akeroyd, Michael A.

    2004-08-01

    The equalization stage in the equalization-cancellation model of binaural unmasking compensates for the interaural time delay (ITD) of a masking noise by introducing an opposite, internal delay [N. I. Durlach, in Foundations of Modern Auditory Theory, Vol. II., edited by J. V. Tobias (Academic, New York, 1972)]. Culling and Summerfield [J. Acoust. Soc. Am. 98, 785-797 (1995)] developed a multi-channel version of this model in which equalization was ``free'' to use the optimal delay in each channel. Two experiments were conducted to test if equalization was indeed free or if it was ``restricted'' to the same delay in all channels. One experiment measured binaural detection thresholds, using an adaptive procedure, for 1-, 5-, or 17-component tones against a broadband masking noise, in three binaural configurations (N0S180, N180S0, and N90S270). The thresholds for the 1-component stimuli were used to normalize the levels of each of the 5- and 17-component stimuli so that they were equally detectable. If equalization was restricted, then, for the 5- and 17-component stimuli, the N90S270 and N180S0 configurations would yield a greater threshold than the N0S180 configurations. No such difference was found. A subsequent experiment measured binaural detection thresholds, via psychometric functions, for a 2-component complex tone in the same three binaural configurations. Again, no differential effect of configuration was observed. An analytic model of the detection of a complex tone showed that the results were more consistent with free equalization than restricted equalization, although the size of the differences was found to depend on the shape of the psychometric function for detection.

  12. Selecting a dynamic simulation modeling method for health care delivery research-part 2: report of the ISPOR Dynamic Simulation Modeling Emerging Good Practices Task Force.

    Science.gov (United States)

    Marshall, Deborah A; Burgos-Liz, Lina; IJzerman, Maarten J; Crown, William; Padula, William V; Wong, Peter K; Pasupathy, Kalyan S; Higashi, Mitchell K; Osgood, Nathaniel D

    2015-03-01

    In a previous report, the ISPOR Task Force on Dynamic Simulation Modeling Applications in Health Care Delivery Research Emerging Good Practices introduced the fundamentals of dynamic simulation modeling and identified the types of health care delivery problems for which dynamic simulation modeling can be used more effectively than other modeling methods. The hierarchical relationship between the health care delivery system, providers, patients, and other stakeholders exhibits a level of complexity that ought to be captured using dynamic simulation modeling methods. As a tool to help researchers decide whether dynamic simulation modeling is an appropriate method for modeling the effects of an intervention on a health care system, we presented the System, Interactions, Multilevel, Understanding, Loops, Agents, Time, Emergence (SIMULATE) checklist consisting of eight elements. This report builds on the previous work, systematically comparing each of the three most commonly used dynamic simulation modeling methods-system dynamics, discrete-event simulation, and agent-based modeling. We review criteria for selecting the most suitable method depending on 1) the purpose-type of problem and research questions being investigated, 2) the object-scope of the model, and 3) the method to model the object to achieve the purpose. Finally, we provide guidance for emerging good practices for dynamic simulation modeling in the health sector, covering all aspects, from the engagement of decision makers in the model design through model maintenance and upkeep. We conclude by providing some recommendations about the application of these methods to add value to informed decision making, with an emphasis on stakeholder engagement, starting with the problem definition. Finally, we identify areas in which further methodological development will likely occur given the growing "volume, velocity and variety" and availability of "big data" to provide empirical evidence and techniques

  13. Temporal Dynamics of Task Switching and Abstract-Concept Learning in Pigeons

    Directory of Open Access Journals (Sweden)

    Thomas Alexander Daniel

    2015-09-01

    Full Text Available The current study examined whether pigeons could learn to use abstract concepts as the basis for conditionally switching behavior as a function of time. Using a mid-session reversal task, experienced pigeons were trained to switch from matching-to-sample (MTS to non-matching-to-sample (NMTS conditional discriminations within a session. One group had prior training with MTS, while the other had prior training with NMTS. Over training, stimulus set size was progressively doubled from 3 to 6 to 12 stimuli to promote abstract concept development. Prior experience had an effect on the initial learning at each of the set sizes but by the end of training there were no group differences, as both groups showed similar within-session linear matching functions. After acquiring the 12-item set, abstract-concept learning was tested by placing novel stimuli at the beginning and end of a test session. Prior matching and non-matching experience affected transfer behavior. The matching experienced group transferred to novel stimuli in both the matching and non-matching portion of the sessions using a matching rule. The non-matching experienced group transferred to novel stimuli in both portions of the session using a non-matching rule. The representations used as the basis for mid-session reversal of the conditional discrimination behaviors and subsequent transfer behavior appears to have different temporal sources. The implications for the flexibility and organization of complex behaviors are considered.

  14. Brain-wave Dynamics Related to Cognitive Tasks and Neurofeedback Information Flow

    Science.gov (United States)

    Pop-Jordanova, Nada; Pop-Jordanov, Jordan; Dimitrovski, Darko; Markovska, Natasa

    2003-08-01

    Synchronization of oscillating neuronal discharges has been recently correlated to the moment of perception and the ensuing motor response, with transition between these two cognitive acts "through cellular mechanisms that remain to be established"[1]. Last year, using genetic strategies, it was found that the switching off persistent electric activity in the brain blocks memory recall [2]. On the other hand, analyzing mental-neural information flow, the nobelist Eccles has formulated a fundamental hypotheses that mental events may change the probability of quantum vesicular emissions of transmitters analogously to probability functions of quantum mechanics [3]. Applying the advanced quantum modeling to molecular rotational states exposed to electric activity in brain cells, we found that the probability of transitions does not depend on the field amplitude, suggesting the electric field frequency as the possible information-bearing physical quantity [4]. In this paper, an attempt is made to inter-correlate the above results on frequency aspects of neural transitions induced by cognitive tasks. Furthermore, considering the consecutive steps of mental-neural information flow during the biofeedback training to normalize EEG frequencies, the rationales for neurofeedback efficiency have been deduced.

  15. Dynamic sequence analysis of a decision making task of multielement target tracking and its usage as a learning method

    Science.gov (United States)

    Kang, Ziho

    This dissertation is divided into four parts: 1) Development of effective methods for comparing visual scanning paths (or scanpaths) for a dynamic task of multiple moving targets, 2) application of the methods to compare the scanpaths of experts and novices for a conflict detection task of multiple aircraft on radar screen, 3) a post-hoc analysis of other eye movement characteristics of experts and novices, and 4) finding out whether the scanpaths of experts can be used to teach the novices. In order to compare experts' and novices' scanpaths, two methods are developed. The first proposed method is the matrix comparisons using the Mantel test. The second proposed method is the maximum transition-based agglomerative hierarchical clustering (MTAHC) where comparisons of multi-level visual groupings are held out. The matrix comparison method was useful for a small number of targets during the preliminary experiment, but turned out to be inapplicable to a realistic case when tens of aircraft were presented on screen; however, MTAHC was effective with large number of aircraft on screen. The experiments with experts and novices on the aircraft conflict detection task showed that their scanpaths are different. The MTAHC result was able to explicitly show how experts visually grouped multiple aircraft based on similar altitudes while novices tended to group them based on convergence. Also, the MTAHC results showed that novices paid much attention to the converging aircraft groups even if they are safely separated by altitude; therefore, less attention was given to the actual conflicting pairs resulting in low correct conflict detection rates. Since the analysis showed the scanpath differences, experts' scanpaths were shown to novices in order to find out its effectiveness. The scanpath treatment group showed indications that they changed their visual movements from trajectory-based to altitude-based movements. Between the treatment and the non-treatment group, there were no

  16. Update report on fracture flow in saturated tuff: Dynamic transport task for the Nevada Nuclear Waste Investigations

    International Nuclear Information System (INIS)

    This report summarizes the results of continuing experiments on the behavior of tracers during fracture flow in saturated, welded tuff. These experiments were completed during the past year as part of the Dynamic Transport Task of geochemical investigations for the Yucca Mountain Project sponsored by the US Department of Energy. These experiments are designed to investigate the effects of fluid movement in fractures when coupled with matrix diffusion and sorption but isolated from the effects of capillary suction and two-phase flow characteristic of unsaturated conditions. The experiments reported here are continuations of experimental efforts reported previously. The behavior of three tracers [HTO (tritiated water), TcO4- (pertechnetate), and sulforhodamine B dye] have been investigated during flow through a saturated column of densely welded tuff from the Topopah Spring Member of the Paintbrush Tuff, Yucca Mountain, Nye County, southern Nevada. 31 refs., 26 figs., 2 tabs

  17. Electrophysiological and psychophysical asymmetries in sensitivity to interaural correlation gaps and implications for binaural integration time.

    Science.gov (United States)

    Lüddemann, Helge; Kollmeier, Birger; Riedel, Helmut

    2016-02-01

    Brief deviations of interaural correlation (IAC) can provide valuable cues for detection, segregation and localization of acoustic signals. This study investigated the processing of such "binaural gaps" in continuously running noise (100-2000 Hz), in comparison to silent "monaural gaps", by measuring late auditory evoked potentials (LAEPs) and perceptual thresholds with novel, iteratively optimized stimuli. Mean perceptual binaural gap duration thresholds exhibited a major asymmetry: they were substantially shorter for uncorrelated gaps in correlated and anticorrelated reference noise (1.75 ms and 4.1 ms) than for correlated and anticorrelated gaps in uncorrelated reference noise (26.5 ms and 39.0 ms). The thresholds also showed a minor asymmetry: they were shorter in the positive than in the negative IAC range. The mean behavioral threshold for monaural gaps was 5.5 ms. For all five gap types, the amplitude of LAEP components N1 and P2 increased linearly with the logarithm of gap duration. While perceptual and electrophysiological thresholds matched for monaural gaps, LAEP thresholds were about twice as long as perceptual thresholds for uncorrelated gaps, but half as long for correlated and anticorrelated gaps. Nevertheless, LAEP thresholds showed the same asymmetries as perceptual thresholds. For gap durations below 30 ms, LAEPs were dominated by the processing of the leading edge of a gap. For longer gap durations, in contrast, both the leading and the lagging edge of a gap contributed to the evoked response. Formulae for the equivalent rectangular duration (ERD) of the binaural system's temporal window were derived for three common window shapes. The psychophysical ERD was 68 ms for diotic and about 40 ms for anti- and uncorrelated noise. After a nonlinear Z-transform of the stimulus IAC prior to temporal integration, ERDs were about 10 ms for reference correlations of ±1 and 80 ms for uncorrelated reference. Hence, a physiologically motivated

  18. Interaction learning for dynamic movement primitives used in cooperative robotic tasks

    DEFF Research Database (Denmark)

    Kulvicius, Tomas; Biehl, Martin; Aein, Mohamad Javad;

    2013-01-01

    Abstract Since several years dynamic movement primitives (DMPs) are more and more getting into the center of interest for flexible movement control in robotics. In this study we introduce sensory feedback together with a predictive learning mechanism which allows tightly coupled dual-agent systems...... to learn an adaptive, sensor-driven interaction based on DMPs. The coupled conventional (no-sensors, no learning) DMP-system automatically equilibrates and can still be solved analytically allowing us to derive conditions for stability. When adding adaptive sensor control we can show that both agents learn...... to cooperate. Simulations as well as real-robot experiments are shown. Interestingly, all these mechanisms are entirely based on low level interactions without any planning or cognitive component....

  19. Hawaii energy strategy project 2: Fossil energy review. Task 1: World and regional fossil energy dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Breazeale, K. [ed.; Isaak, D.T.; Yamaguchi, N.; Fridley, D.; Johnson, C.; Long, S.

    1993-12-01

    This report in the Hawaii Energy Strategy Project examines world and regional fossil energy dynamics. The topics of the report include fossil energy characteristics, the world oil industry including reserves, production, consumption, exporters, importers, refining, products and their uses, history and trends in the global oil market and the Asia-Pacific market; world gas industry including reserves, production, consumption, exporters, importers, processing, gas-based products, international gas market and the emerging Asia-Pacific gas market; the world coal industry including reserves, classification and quality, utilization, transportation, pricing, world coal market, Asia-Pacific coal outlook, trends in Europe and the Americas; and environmental trends affecting fossil fuels. 132 figs., 46 tabs.

  20. Understanding and Mastering Dynamics in Computing Grids Processing Moldable Tasks with User-Level Overlay

    CERN Document Server

    Moscicki, Jakub Tomasz

    Scientic communities are using a growing number of distributed systems, from lo- cal batch systems, community-specic services and supercomputers to general-purpose, global grid infrastructures. Increasing the research capabilities for science is the raison d'^etre of such infrastructures which provide access to diversied computational, storage and data resources at large scales. Grids are rather chaotic, highly heterogeneous, de- centralized systems where unpredictable workloads, component failures and variability of execution environments are commonplace. Understanding and mastering the hetero- geneity and dynamics of such distributed systems is prohibitive for end users if they are not supported by appropriate methods and tools. The time cost to learn and use the interfaces and idiosyncrasies of dierent distributed environments is another challenge. Obtaining more reliable application execution times and boosting parallel speedup are important to increase the research capabilities of scientic communities. L...

  1. Lateral reflections are favorable in concert halls due to binaural loudness.

    Science.gov (United States)

    Lokki, Tapio; Pätynen, Jukka

    2011-11-01

    A recent study on perceptual difference in simulated concert halls showed that a concert hall renders stronger sound with more bass when the temporal envelope of a signal is preserved in the reflections [Lokki et al., J. Acoust. Soc. Am. 129, EL223-EL228 (2011)]. In the same study the lateral reflections were shown to contribute to the perceived envelopment and openness. Moreover, the listening test results suggest that lateral reflections contribute to perception of sound source distance. Here, it is shown that lateral reflections are beneficial due to their increasing effect on binaural loudness-the phenomenon known well in psychoacoustics, but not in architectural acoustics. The reflections from the side are amplified more than median plane reflections, in particular at high frequencies, due to the shape of the human head. PMID:22088039

  2. Intelligibility for Binaural Speech with Discarded Low-SNR Speech Components.

    Science.gov (United States)

    Schoenmaker, Esther; van de Par, Steven

    2016-01-01

    Speech intelligibility in multitalker settings improves when the target speaker is spatially separated from the interfering speakers. A factor that may contribute to this improvement is the improved detectability of target-speech components due to binaural interaction in analogy to the Binaural Masking Level Difference (BMLD). This would allow listeners to hear target speech components within specific time-frequency intervals that have a negative SNR, similar to the improvement in the detectability of a tone in noise when these contain disparate interaural difference cues. To investigate whether these negative-SNR target-speech components indeed contribute to speech intelligibility, a stimulus manipulation was performed where all target components were removed when local SNRs were smaller than a certain criterion value. It can be expected that for sufficiently high criterion values target speech components will be removed that do contribute to speech intelligibility. For spatially separated speakers, assuming that a BMLD-like detection advantage contributes to intelligibility, degradation in intelligibility is expected already at criterion values below 0 dB SNR. However, for collocated speakers it is expected that higher criterion values can be applied without impairing speech intelligibility. Results show that degradation of intelligibility for separated speakers is only seen for criterion values of 0 dB and above, indicating a negligible contribution of a BMLD-like detection advantage in multitalker settings. These results show that the spatial benefit is related to a spatial separation of speech components at positive local SNRs rather than to a BMLD-like detection improvement for speech components at negative local SNRs. PMID:27080648

  3. A Sparsity-Based Approach to 3D Binaural Sound Synthesis Using Time-Frequency Array Processing

    Directory of Open Access Journals (Sweden)

    Spors Sascha

    2010-01-01

    Full Text Available Localization of sounds in physical space plays a very important role in multiple audio-related disciplines, such as music, telecommunications, and audiovisual productions. Binaural recording is the most commonly used method to provide an immersive sound experience by means of headphone reproduction. However, it requires a very specific recording setup using high-fidelity microphones mounted in a dummy head. In this paper, we present a novel processing framework for binaural sound recording and reproduction that avoids the use of dummy heads, which is specially suitable for immersive teleconferencing applications. The method is based on a time-frequency analysis of the spatial properties of the sound picked up by a simple tetrahedral microphone array, assuming source sparseness. The experiments carried out using simulations and a real-time prototype confirm the validity of the proposed approach.

  4. Benefits to Speech Perception in Noise From the Binaural Integration of Electric and Acoustic Signals in Simulated Unilateral Deafness

    OpenAIRE

    Ma, Ning; Morris, Saffron; Kitterick, Pádraig Thomas

    2015-01-01

    Objectives: This study used vocoder simulations with normal-hearing (NH) listeners to (1) measure their ability to integrate speech information from an NH ear and a simulated cochlear implant (CI), and (2) investigate whether binaural integration is disrupted by a mismatch in the delivery of spectral information between the ears arising from a misalignment in the mapping of frequency to place. Design: Eight NH volunteers participated in the study and listened to sentences embedded in backgrou...

  5. Dynamic modulation of local population activity by rhythm phase in human occipital cortex during a visual search task

    Directory of Open Access Journals (Sweden)

    Kai J Miller

    2010-10-01

    Full Text Available Brain rhythms are more than just passive phenomena in visual cortex. For the first time, we show that the physiology underlying brain rhythms actively suppresses and releases cortical areas on a second-to-second basis during visual processing. Furthermore, their influence is specific at the scale of individual gyri. We quantified the interaction between broadband spectral change and brain rhythms on a second-to-second basis in electrocorticographic (ECoG measurement of brain surface potentials in five human subjects during a visual search task. Comparison of visual search epochs with a blank screen baseline revealed changes in the raw potential, the amplitude of rhythmic activity, and in the decoupled broadband spectral amplitude. We present new methods to characterize the intensity and preferred phase of coupling between broadband power and band-limited rhythms, and to estimate the magnitude of rhythm-to-broadband modulation on a trial-by-trial basis. These tools revealed numerous coupling motifs between the phase of low frequency (δ, θ, α, β, and γ band rhythms and the amplitude of broadband spectral change. In the θ and β ranges, the coupling of phase to broadband change is dynamic during visual processing, decreasing in some occipital areas and increasing in others, in a gyrally specific pattern. Finally, we demonstrate that the rhythms interact with one another across frequency ranges, and across cortical sites.

  6. Task-Related Dynamic Division of Labor Between Anterior Temporal and Lateral Occipital Cortices in Representing Object Size

    Science.gov (United States)

    2016-01-01

    top-down” cognitive state of an observer changes the dynamic interaction between different subregions of the ventral temporal cortex. Using inhibitory neurostimulation combined with a novel paradigm, we demonstrate a flexible division of labor in the neurocognitive architecture that underpins size knowledge: the lateral occipital cortex codes perceptually based aspects (statistical visual configuration of small/large objects), whereas the anterior temporal lobe represents semantically based aspects (object identity), with their involvement interactively weighted by task demand. The interactive nature of the ventral temporal cortex highlights how top-down modulation constrains and shapes neural representations in the visual system. PMID:27122025

  7. Modality-specific spectral dynamics in response to visual and tactile sequential shape information processing tasks: An MEG study using multivariate pattern classification analysis.

    Science.gov (United States)

    Gohel, Bakul; Lee, Peter; Jeong, Yong

    2016-08-01

    Brain regions that respond to more than one sensory modality are characterized as multisensory regions. Studies on the processing of shape or object information have revealed recruitment of the lateral occipital cortex, posterior parietal cortex, and other regions regardless of input sensory modalities. However, it remains unknown whether such regions show similar (modality-invariant) or different (modality-specific) neural oscillatory dynamics, as recorded using magnetoencephalography (MEG), in response to identical shape information processing tasks delivered to different sensory modalities. Modality-invariant or modality-specific neural oscillatory dynamics indirectly suggest modality-independent or modality-dependent participation of particular brain regions, respectively. Therefore, this study investigated the modality-specificity of neural oscillatory dynamics in the form of spectral power modulation patterns in response to visual and tactile sequential shape-processing tasks that are well-matched in terms of speed and content between the sensory modalities. Task-related changes in spectral power modulation and differences in spectral power modulation between sensory modalities were investigated at source-space (voxel) level, using a multivariate pattern classification (MVPC) approach. Additionally, whole analyses were extended from the voxel level to the independent-component level to take account of signal leakage effects caused by inverse solution. The modality-specific spectral dynamics in multisensory and higher-order brain regions, such as the lateral occipital cortex, posterior parietal cortex, inferior temporal cortex, and other brain regions, showed task-related modulation in response to both sensory modalities. This suggests modality-dependency of such brain regions on the input sensory modality for sequential shape-information processing. PMID:27134037

  8. Studies on Bilateral Cochlear Implants at the University of Wisconsin’s Binaural Hearing and Speech Lab

    OpenAIRE

    Litovsky, Ruth Y.; Goupell, Matthew J.; Godar, Shelly; Grieco-Calub, Tina; Jones, Gary L.; Garadat, Soha N.; Agrawal, Smita; Kan, Alan; Todd, Ann; Hess, Christi; Misurelli, Sara

    2012-01-01

    This report highlights research projects relevant to binaural and spatial hearing in adults and children. In the past decade we have made progress in understanding the impact of bilateral cochlear implants (BiCIs) on performance in adults and children. However, BiCI users typically do not perform as well as normal hearing (NH) listeners. In this paper we describe the benefits from BiCIs compared with a single CI, focusing on measures of spatial hearing and speech understanding in noise. We hi...

  9. The binaural free field hearing threshold for pure tones from 125 Hz to 16 kHz

    DEFF Research Database (Denmark)

    Poulsen, Torben; Han, Loc A

    2000-01-01

    The binaural free field hearing threshold for pure tones has been measured for thirty-one otologically normal test subjects in the age range 18 to 25 years. The frequencies were 0.125, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 9, 10, 11.2, 12.5, 14 and 16 kHz. The signal duration was 1 s measured...... the free field hearing threshold. At 1500 Hz a small local peak in the threshold is seen which is not reflected in the present standards.PACS 43.66 Cb; 43.66 Pn...

  10. Scheduling PVM Tasks

    Institute of Scientific and Technical Information of China (English)

    鞠九滨; 王勇; 等

    1997-01-01

    This paper describes a PVM task scheduler designed and implemented by the authors.The scheduler supports selecting idle workstations,scheduling pool tasks and dynamically produced subtasks.It can improve resource utilization,reduce job response time and simplify programming.

  11. The neural dynamics of stimulus and response conflict processing as a function of response complexity and task demands.

    Science.gov (United States)

    Donohue, Sarah E; Appelbaum, Lawrence G; McKay, Cameron C; Woldorff, Marty G

    2016-04-01

    Both stimulus and response conflict can disrupt behavior by slowing response times and decreasing accuracy. Although several neural activations have been associated with conflict processing, it is unclear how specific any of these are to the type of stimulus conflict or the amount of response conflict. Here, we recorded electrical brain activity, while manipulating the type of stimulus conflict in the task (spatial [Flanker] versus semantic [Stroop]) and the amount of response conflict (two versus four response choices). Behaviorally, responses were slower to incongruent versus congruent stimuli across all task and response types, along with overall slowing for higher response-mapping complexity. The earliest incongruency-related neural effect was a short-duration frontally-distributed negativity at ~200 ms that was only present in the Flanker spatial-conflict task. At longer latencies, the classic fronto-central incongruency-related negativity 'Ninc' was observed for all conditions, but was larger and ~100 ms longer in duration with more response options. Further, the onset of the motor-related lateralized readiness potential (LRP) was earlier for the two vs. four response sets, indicating that smaller response sets enabled faster motor-response preparation. The late positive complex (LPC) was present in all conditions except the two-response Stroop task, suggesting this late conflict-related activity is not specifically related to task type or response-mapping complexity. Importantly, across tasks and conditions, the LRP onset at or before the conflict-related Ninc, indicating that motor preparation is a rapid, automatic process that interacts with the conflict-detection processes after it has begun. Together, these data highlight how different conflict-related processes operate in parallel and depend on both the cognitive demands of the task and the number of response options. PMID:26827917

  12. Functional segregation of monaural and binaural selectivity in the pallid bat auditory cortex.

    Science.gov (United States)

    Razak, Khaleel A

    2016-07-01

    Different fields of the auditory cortex can be distinguished by the extent and level tolerance of spatial selectivity. The mechanisms underlying the range of spatial tuning properties observed across cortical fields are unclear. Here, this issue was addressed in the pallid bat because its auditory cortex contains two segregated regions of response selectivity that serve two different behaviors: echolocation for obstacle avoidance and localization of prey-generated noise. This provides the unique opportunity to examine mechanisms of spatial properties in two functionally distinct regions. Previous studies have shown that spatial selectivity of neurons in the region selective for noise (noise-selective region, NSR) is level tolerant and shaped by interaural level difference (ILD) selectivity. In contrast, spatial selectivity of neurons in the echolocation region ('FM sweep-selective region' or FMSR) is strongly level dependent with many neurons responding to multiple distinct spatial locations for louder sounds. To determine the mechanisms underlying such level dependence, frequency, azimuth, rate-level responses and ILD selectivity were measured from the same FMSR neurons. The majority (∼75%) of FMSR neurons were monaural (ILD insensitive). Azimuth tuning curves expanded or split into multiple peaks with increasing sound level in a manner that was predicted by the rate-level response of neurons. These data suggest that azimuth selectivity of FMSR neurons depends more on monaural ear directionality and rate-level responses. The pallid bat cortex utilizes segregated monaural and binaural regions to process echoes and prey-generated noise. Together the pallid bat FMSR/NSR data provide mechanistic explanations for a broad range of spatial tuning properties seen across species. PMID:27233917

  13. Dual-microphone and binaural noise reduction techniques for improved speech intelligibility by hearing aid users

    Science.gov (United States)

    Yousefian Jazi, Nima

    Spatial filtering and directional discrimination has been shown to be an effective pre-processing approach for noise reduction in microphone array systems. In dual-microphone hearing aids, fixed and adaptive beamforming techniques are the most common solutions for enhancing the desired speech and rejecting unwanted signals captured by the microphones. In fact, beamformers are widely utilized in systems where spatial properties of target source (usually in front of the listener) is assumed to be known. In this dissertation, some dual-microphone coherence-based speech enhancement techniques applicable to hearing aids are proposed. All proposed algorithms operate in the frequency domain and (like traditional beamforming techniques) are purely based on the spatial properties of the desired speech source and does not require any knowledge of noise statistics for calculating the noise reduction filter. This benefit gives our algorithms the ability to address adverse noise conditions, such as situations where interfering talker(s) speaks simultaneously with the target speaker. In such cases, the (adaptive) beamformers lose their effectiveness in suppressing interference, since the noise channel (reference) cannot be built and updated accordingly. This difference is the main advantage of the proposed techniques in the dissertation over traditional adaptive beamformers. Furthermore, since the suggested algorithms are independent of noise estimation, they offer significant improvement in scenarios that the power level of interfering sources are much more than that of target speech. The dissertation also shows the premise behind the proposed algorithms can be extended and employed to binaural hearing aids. The main purpose of the investigated techniques is to enhance the intelligibility level of speech, measured through subjective listening tests with normal hearing and cochlear implant listeners. However, the improvement in quality of the output speech achieved by the

  14. Windowed correlation: a suitable tool for providing dynamic fMRI-based functional connectivity neurofeedback on task difficulty.

    Directory of Open Access Journals (Sweden)

    Anna Zilverstand

    Full Text Available The goal of neurofeedback training is to provide participants with relevant information on their ongoing brain processes in order to enable them to change these processes in a meaningful way. Under the assumption of an intrinsic brain-behavior link, neurofeedback can be a tool to guide a participant towards a desired behavioral state, such as a healthier state in the case of patients. Current research in clinical neuroscience regarding the most robust indicators of pathological brain processes in psychiatric and neurological disorders indicates that fMRI-based functional connectivity measures may be among the most important biomarkers of disease. The present study therefore investigated the general potential of providing fMRI neurofeedback based on functional correlations, computed from short-window time course data at the level of single task periods. The ability to detect subtle changes in task performance with block-wise functional connectivity measures was evaluated based on imaging data from healthy participants performing a simple motor task, which was systematically varied along two task dimensions representing two different aspects of task difficulty. The results demonstrate that fMRI-based functional connectivity measures may provide a better indicator for an increase in overall (motor task difficulty than activation level-based measures. Windowed functional correlations thus seem to provide relevant and unique information regarding ongoing brain processes, which is not captured equally well by standard activation level-based neurofeedback measures. Functional connectivity markers, therefore, may indeed provide a valuable tool to enhance and monitor learning within an fMRI neurofeedback setup.

  15. Dynamic navigation simulation of an articulated multi-link arm for in-vessel inspection tasks in a Tokamak

    International Nuclear Information System (INIS)

    This paper is part of the remote handling (RH) activities towards preparedness for the future fusion machines. The aim of the R and D program performed is to demonstrate the feasibility of the inspection tasks inside the Vacuum Vessel. Due to the toroidal geometry and huge dimensions of the Vacuum Vessel, there is an inevitable need of a precise and fast automated articulated inspection system that can perform the required inspection tasks without damaging the surface and to maintain the machine availability for the maximum time. When considering generic Tokamak relevant conditions, the set of major challenges for the Remote Equipment is to sustain the severe operating conditions: ultra high vacuum, temperature and tritium level. The limited number of machine access ports and the very constrained environment complicate the introduction of a robot into the machine. The Multi Link inspection arm is required to be deployed in the bounded environment inside the Tokamak Vessel. This paper presents the development of software for implementation of autonomous navigation motion control algorithms based design simulations for the inspection Arm for routine inspection tasks, navigation to the targeted coordinates inside the Vessel, clash avoidance and to perform other auxiliary mechanical tasks. The software is also capable to store the joints and frame locations at every interval which can be used for the real time control application. The developed software has the flexibility to work with any number of links and joints. (author)

  16. Auto-adaptative Robot-aided Therapy based in 3D Virtual Tasks controlled by a Supervised and Dynamic Neuro-Fuzzy System

    Directory of Open Access Journals (Sweden)

    Luis Daniel Lledó

    2015-03-01

    Full Text Available This paper presents an application formed by a classification method based on the architecture of ART neural network (Adaptive Resonance Theory and the Fuzzy Set Theory to classify physiological reactions in order to automatically and dynamically adapt a robot-assisted rehabilitation therapy to the patient needs, using a three-dimensional task in a virtual reality system. Firstly, the mathematical and structural model of the neuro-fuzzy classification method is described together with the signal and training data acquisition. Then, the virtual designed task with physics behavior and its development procedure are explained. Finally, the general architecture of the experimentation for the auto-adaptive therapy is presented using the classification method with the virtual reality exercise.

  17. Predicting binaural speech intelligibility using the signal-to-noise ratio in the envelope power spectrum domain.

    Science.gov (United States)

    Chabot-Leclerc, Alexandre; MacDonald, Ewen N; Dau, Torsten

    2016-07-01

    This study proposes a binaural extension to the multi-resolution speech-based envelope power spectrum model (mr-sEPSM) [Jørgensen, Ewert, and Dau (2013). J. Acoust. Soc. Am. 134, 436-446]. It consists of a combination of better-ear (BE) and binaural unmasking processes, implemented as two monaural realizations of the mr-sEPSM combined with a short-term equalization-cancellation process, and uses the signal-to-noise ratio in the envelope domain (SNRenv) as the decision metric. The model requires only two parameters to be fitted per speech material and does not require an explicit frequency weighting. The model was validated against three data sets from the literature, which covered the following effects: the number of maskers, the masker types [speech-shaped noise (SSN), speech-modulated SSN, babble, and reversed speech], the masker(s) azimuths, reverberation on the target and masker, and the interaural time difference of the target and masker. The Pearson correlation coefficient between the simulated speech reception thresholds and the data across all experiments was 0.91. A model version that considered only BE processing performed similarly (correlation coefficient of 0.86) to the complete model, suggesting that BE processing could be considered sufficient to predict intelligibility in most realistic conditions. PMID:27475146

  18. Neural-network-based two-loop control of robotic manipulators including actuator dynamics in task space

    Institute of Scientific and Technical Information of China (English)

    Liangyong WANG; Tianyou CHAI; Zheng FANG

    2009-01-01

    A neural-network-based motion controller in task space is presented in this paper. The proposed controller is addressed as a two-loop cascade control scheme. The outer loop is given by kinematic control in the task space. It provides a joint velocity reference signal to the inner one. The inner loop implements a velocity servo loop at the robot joint level. A radial basis function network (RBFN) is integrated with proportional-integral (PI) control to construct a velocity tracking control scheme for the inner loop. Finally, a prototype technology based control system is designed for a robotic manipulator. The proposed control scheme is applied to the robotic manipulator. Experimental results confirm the validity of the proposed control scheme by comparing it with other control strategies.

  19. Subject-Specific Tendon-Aponeurosis Definition in Hill-Type Model Predicts Higher Muscle Forces in Dynamic Tasks

    OpenAIRE

    Gerus, Pauline; Rao, Guillaume; Berton, Eric

    2012-01-01

    Neuromusculoskeletal models are a common method to estimate muscle forces. Developing accurate neuromusculoskeletal models is a challenging task due to the complexity of the system and large inter-subject variability. The estimation of muscles force is based on the mechanical properties of tendon-aponeurosis complex. Most neuromusculoskeletal models use a generic definition of the tendon-aponeurosis complex based on in vitro test, perhaps limiting their validity. Ultrasonography allows subjec...

  20. Interferência binaural no processo de seleção e adaptação de próteses auditivas: revisão sistemática

    OpenAIRE

    Milena Manoel Azevedo; Ana Valéria de Almeida Vaucher; Mariana Teixeira Duarte; Eliara Pinto Vieira Biaggio; Maristela Julio Costa

    2013-01-01

    O tema deste estudo é a interferência binaural e tem como objetivo descrever, por meio de revisão teórica, o fenômeno caracterizado por interferência binaural. Será realizada revisão sistemática por meio de pesquisa nas bases de dados LILACS, MEDLINE, PUBMED e SCIELO. O fenômeno interferência binaural é uma realidade relatada na literatura, que precisa ser investigado. Pode se confirmar por testes específicos de processamento auditivo, o mais descrito foi o dicótico de dígitos.

  1. New evidence for strategic differences between static and dynamic search tasks: An individual observer analysis of eye movements

    Directory of Open Access Journals (Sweden)

    Christopher eDickinson

    2013-01-01

    Full Text Available Two experiments are reported that further explore the processes underlying dynamic search. In Experiment 1, observers’ oculomotor behavior was monitored while they searched for a randomly oriented T among oriented L distractors under static and dynamic viewing conditions. Despite similar search slopes, eye movements were less frequent and more spatially constrained under dynamic viewing relative to static, with misses also increasing more with target eccentricity in the dynamic condition. These patterns suggest that dynamic search involves a form of sit-and-wait strategy in which search is restricted to a small group of items surrounding fixation. To evaluate this interpretation, we developed a computational model of a sit-and-wait process hypothesized to underlie dynamic search. In Experiment 2 we tested this model by varying fixation position in the display and found that display positions optimized for a sit-and-wait strategy resulted in higher d' values relative to a less optimal location. We conclude that different strategies, and therefore underlying processes, are used to search static and dynamic displays.

  2. Changes in regional cerebral blood flow during auditory cognitive tasks

    International Nuclear Information System (INIS)

    In order to investigate the relation between auditory cognitive function and regional brain activation, we measured the changes in the regional cerebral blood flow (CBF) using positron emission tomography (PET) during the 'odd-ball' paradigm in ten normal healthy volunteers. The subjects underwent 3 tasks, twice for each, while the evoked potential was recorded. In these tasks, the auditory stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB from the earphones. Task A: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to only hear. Task B: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to push the button on detecting a tone. Task C: the stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB with a frequency of 1000 Hz (non-target) in 80% and 2000 Hz (target) in 20% at random, and the subject was instructed to push the button on detecting a target tone. The event related potential (P300) was observed in task C (Pz: 334.3±19.6 msec). At each task, the CBF was measured using PET with i.v. injection of 1.5 GBq of O-15 water. The changes in CBF associated with auditory cognition was evaluated by the difference between the CBF images in task C and B. Localized increase was observed in the anterior cingulate cortex (in all subjects), the bilateral associate auditory cortex, the prefrontal cortex and the parietal cortex. The latter three areas had a large individual variation in the location of foci. These results suggested the role of those cortical areas in auditory cognition. The anterior cingulate was most activated (15.0±2.24% of global CBF). This region was not activated in the condition of task B minus task A. The anterior cingulate is a part of Papez's circuit that is related to memory and other higher cortical function. These results suggested that this area may play an important role in cognition as well as in attention. (author)

  3. Developing a dynamic geometry task platform for accessing students' perceptions of geometric properties through analysis of example spaces

    OpenAIRE

    Lee, Man-sang, Arthur; 李文生

    2015-01-01

    Geometry learning at the junior secondary level should focus on the connection between students’ intuitive, spatial thinking and formal, deductive reasoning. It is crucial for students at this stage to develop abstract concepts based on knowledge of and reasoning with geometric properties. Dynamic geometry tools are promising resources in classroom teaching for enriching students’ experience in geometry. Studies about students’ learning with dynamic geometry tools usually focus on the lon...

  4. Comparison of proximally versus distally placed spatially distributed sequential stimulation electrodes in a dynamic knee extension task

    Directory of Open Access Journals (Sweden)

    Marco Laubacher

    2016-06-01

    Full Text Available Spatially distributed sequential stimulation (SDSS has demonstrated substantial power output and fatigue benefits compared to single electrode stimulation (SES in the application of functional electrical stimulation (FES. This asymmetric electrode setup brings new possibilities but also new questions since precise placement of the electrodes is one critical factor for good muscle activation. The aim of this study was to compare the power output, fatigue and activation properties of proximally versus distally placed SDSS electrodes in an isokinetic knee extension task simulating knee movement during recumbent cycling. M. vastus lateralis and medialis of seven able-bodied subjects were stimulated with rectangular bi-phasic pulses of constant amplitude of 40 mA and at an SDSS frequency of 35 Hz for 6 min on both legs with both setups (i.e. n=14. Torque was measured during knee-extension movement by a dynamometer at an angular velocity of 110 deg/s. Mean power, peak power and activation time were calculated and compared for the initial and final stimulation phases, together with an overall fatigue index. Power output values (Pmean, Ppeak were scaled to a standardised reference input pulse width of 100 μs (Pmean,s, Ppeak,s. The initial evaluation phase showed no significant differences between the two setups for all outcome measures. Ppeak and Ppeak,s were both significantly higher in the final phase for the distal setup (25.4 ± 8.1 W vs. 28.2 ± 6.2 W, p=0.0062 and 34.8 ± 9.5 W vs. 38.9 ± 6.7 W, p=0.021, respectively. With distal SDSS, there was modest evidence of higher Pmean and Pmean,s (p=0.071, p=0.14, respectively but of longer activation time (p=0.096. The rate of fatigue was similar for both setups. For practical FES applications, distal placement of the SDSS electrodes is preferable.

  5. Effect of monaural and binaural stimulation on cytoplasmic RNA content in cells of the central nucleus of the cat inferior colliculus.

    Science.gov (United States)

    Shmigidina, G N

    1981-01-01

    A cytophotometric study of sections stained with gallocyanin and chrome alum showed that monaural stimulation for 2 h and binaural stimulation for 1.5 h with rhythmic noise signals led to a marked increase in the cytoplasmic RNA content per cell in the principal and large multipolar neurons of the dorsal and ventral parts of the ventrolateral region of the central nucleus of the inferior colliculus. The increase in cytoplasmic RNA content in the principal cells of the ipsi- and contralateral parts of this nucleus relative to the stimulated ear in the case of monaural stimulation and the increase in RNA content in response to binaural stimulation suggests a uniform distribution of bilaterally converging connections from the lower nuclei of the auditory system on the principal cells. The increase in cytoplasmic RNA in the large multipolar cells of the contralateral central nucleus in response to monaural stimulation is evidence of the predominantly contralateral projection to these cells. The results are evidence of convergence of binaural influences on the principal and large multipolar cells of the central nucleus of the inferior colliculus. PMID:6173796

  6. CEINMS: A toolbox to investigate the influence of different neural control solutions on the prediction of muscle excitation and joint moments during dynamic motor tasks.

    Science.gov (United States)

    Pizzolato, Claudio; Lloyd, David G; Sartori, Massimo; Ceseracciu, Elena; Besier, Thor F; Fregly, Benjamin J; Reggiani, Monica

    2015-11-01

    Personalized neuromusculoskeletal (NMS) models can represent the neurological, physiological, and anatomical characteristics of an individual and can be used to estimate the forces generated inside the human body. Currently, publicly available software to calculate muscle forces are restricted to static and dynamic optimisation methods, or limited to isometric tasks only. We have created and made freely available for the research community the Calibrated EMG-Informed NMS Modelling Toolbox (CEINMS), an OpenSim plug-in that enables investigators to predict different neural control solutions for the same musculoskeletal geometry and measured movements. CEINMS comprises EMG-driven and EMG-informed algorithms that have been previously published and tested. It operates on dynamic skeletal models possessing any number of degrees of freedom and musculotendon units and can be calibrated to the individual to predict measured joint moments and EMG patterns. In this paper we describe the components of CEINMS and its integration with OpenSim. We then analyse how EMG-driven, EMG-assisted, and static optimisation neural control solutions affect the estimated joint moments, muscle forces, and muscle excitations, including muscle co-contraction. PMID:26522621

  7. The Impact of Task Demands on Fixation-Related Brain Potentials during Guided Search

    Science.gov (United States)

    Ahrens, Barry; Connolly, Patrick

    2016-01-01

    Recording synchronous data from EEG and eye-tracking provides a unique methodological approach for measuring the sensory and cognitive processes of overt visual search. Using this approach we obtained fixation related potentials (FRPs) during a guided visual search task specifically focusing on the lambda and P3 components. An outstanding question is whether the lambda and P3 FRP components are influenced by concurrent task demands. We addressed this question by obtaining simultaneous eye-movement and electroencephalographic (EEG) measures during a guided visual search task while parametrically modulating working memory load using an auditory N-back task. Participants performed the guided search task alone, while ignoring binaurally presented digits, or while using the auditory information in a 0, 1, or 2-back task. The results showed increased reaction time and decreased accuracy in both the visual search and N-back tasks as a function of auditory load. Moreover, high auditory task demands increased the P3 but not the lambda latency while the amplitude of both lambda and P3 was reduced during high auditory task demands. The results show that both early and late stages of visual processing indexed by FRPs are significantly affected by concurrent task demands imposed by auditory working memory. PMID:27286248

  8. The binaural free field hearing threshold for pure tones from 125 Hz to 16 kHz

    DEFF Research Database (Denmark)

    Poulsen, Torben; Han, Loc A

    2000-01-01

    The binaural free field hearing threshold for pure tones has been measured for thirty-one otologically normal test subjects in the age range 18 to 25 years. The frequencies were 0.125, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 9, 10, 11.2, 12.5, 14 and 16 kHz. The signal duration was 1 s measured...... between the half amplitude points of the rise and fall course. The pure tone signals were generated from disk files. The thresholds were determined with the Bracketing Method (ISO 8253-1) using a step size of 5 dB. The results are in good agreement with ISO 389-7 and with other recent determinations of...... the free field hearing threshold. At 1500 Hz a small local peak in the threshold is seen which is not reflected in the present standards.PACS 43.66 Cb; 43.66 Pn...

  9. The observation of theta wave modulation on brain training by 5 Hz-binaural beat stimulation in seven days.

    Science.gov (United States)

    Yamsa-Ard, Traisak; Wongsawat, Yodchanan

    2015-08-01

    Traditional buddhist meditation method maybe easy for someone with high experience. However, for the beginner, it is very difficult to keep mental concentration with the tradition way for more than 5 minutes. This research aims to observe effect of the new method for meditation in various analysis methods. A piano music mixed with a 5 Hz (theta band enhancement) binaural beat frequency was used to modulate the brain signals continuously for 7 days. Male of the average age of 33.5±3.84 and female of the average age of 28.6±2.49 were participated. All participants were acquired EEGs twice, before the experiment and seven days after the experiment. We also proposed the observations on the changes of absolute powers, relative powers and brain connectivity (coherence) of the participants. After seven days of training, the absolute power, relative power, and coherence were clearly closer to the normative database. We can initially say that the recommended meditation method can efficiently mimic the effect of having the traditional buddhist meditation on enhancing the delta and theta powers in the brain. PMID:26737822

  10. A new asymmetric directional microphone algorithm with automatic mode-switching ability for binaural hearing support devices.

    Science.gov (United States)

    Kim, Jinryoul; Nam, Kyoung Won; Yook, Sunhyun; Jang, Dong Pyo; Kim, In Young; Hong, Sung Hwa

    2015-06-01

    For hearing support devices, it is important to minimize the negative effect of ambient noises for speech recognition but also, at the same time, supply natural ambient sounds to the hearing-impaired person. However, conventional fixed bilateral asymmetric directional microphone (DM) algorithms cannot perform in such a way when the DM-mode device and a dominant noise (DN) source are placed on the same lateral hemisphere. In this study, a new binaural asymmetric DM algorithm that can overcome the defects of conventional algorithms is proposed. The proposed algorithm can estimate the position of a specific DN in the 90°-270° range and switch directional- and omnidirectional-mode devices automatically if the DM-mode device and the DN are placed in opposite lateral hemispheres. Computer simulation and KEMAR mannequin recording tests demonstrated that the performance of the conventional algorithm deteriorated when the DM-mode device and the DN were placed in the opposite hemisphere; in contrast, the performance of the proposed algorithm was consistently maintained regardless of directional variations in the DN. Based on these experimental results, the proposed algorithm may be able to improve speech quality and intelligibility for hearing-impaired persons who have similar degrees of hearing impairment in both ears. PMID:25597956

  11. Evaluation of a dual-channel full dynamic range compression system for people with sensorineural hearing loss.

    Science.gov (United States)

    Moore, B C; Johnson, J S; Clark, T M; Pluvinage, V

    1992-10-01

    This article describes an evaluation of an in the ear hearing aid, which applies fast-acting full dynamic range compression independently in two frequency bands. This can compensate for the loudness recruitment typically associated with sensorineural hearing loss. The crossover frequency between the two bands and the gain and compression ratio in each band are programmable to suit the individual patient. Twenty subjects with moderate sensorineural hearing loss were tested in a counterbalanced order using the aid programmed as a linear amplifier (condition L) and as a two-band compressor (condition C). All subjects were fitted binaurally. Subjects were also tested without hearing aids (condition U) and using the hearing aids that they normally wore (condition Own). Speech intelligibility was measured in quiet at three sound levels (50, 65, and 80 dB SPL), and speech reception thresholds (SRTs) in 12-talker babble were measured under monaurally and binaurally aided conditions, with the speech and babble both coincident and spatially separated. In condition C, speech intelligibility in quiet was high at all sound levels. Speech intelligibility at the two lower levels decreased in condition L, and decreased still further in conditions Own and U. Condition C gave, on average, better speech intelligibility in babble (lower SRTs) than conditions L, Own, or U. The advantage of condition C over condition L varied across subjects and was correlated with the dynamic range for tones at high frequencies; small dynamic ranges were associated with greater benefit from compression. A significant advantage for binaural aiding was found both when the speech and noise were spatially separated and when they were coincident. The binaural advantage was similar for the C and L conditions, indicating that the independent compression at the two ears did not adversely affect the use of binaural cues. Questionnaires on the subjects' experiences with the aids in everyday life indicated that

  12. Spatial and temporal dynamics of visual search tasks distinguish subtypes of unilateral spatial neglect: Comparison of two cases with viewer-centered and stimulus-centered neglect.

    Science.gov (United States)

    Mizuno, Katsuhiro; Kato, Kenji; Tsuji, Tetsuya; Shindo, Keiichiro; Kobayashi, Yukiko; Liu, Meigen

    2016-08-01

    We developed a computerised test to evaluate unilateral spatial neglect (USN) using a touchscreen display, and estimated the spatial and temporal patterns of visual search in USN patients. The results between a viewer-centered USN patient and a stimulus-centered USN patient were compared. Two right-brain-damaged patients with USN, a patient without USN, and 16 healthy subjects performed a simple cancellation test, the circle test, a visuomotor search test, and a visual search test. According to the results of the circle test, one USN patient had stimulus-centered neglect and a one had viewer-centered neglect. The spatial and temporal patterns of these two USN patients were compared. The spatial and temporal patterns of cancellation were different in the stimulus-centered USN patient and the viewer-centered USN patient. The viewer-centered USN patient completed the simple cancellation task, but paused when transferring from the right side to the left side of the display. Unexpectedly, this patient did not exhibit rightward attention bias on the visuomotor and visual search tests, but the stimulus-centered USN patient did. The computer-based assessment system provided information on the dynamic visual search strategy of patients with USN. The spatial and temporal pattern of cancellation and visual search were different across the two patients with different subtypes of neglect. PMID:26059555

  13. Simulating the Emergence of Task Rotation

    OpenAIRE

    Kees Zoethout; Wander Jager; Eric Molleman

    2006-01-01

    In work groups, task rotation may decrease the negative consequences of boredom and lead to a better task performance. In this paper we use multi agent simulation to study several organisation types in which task rotation may or may not emerge. By looking at the development of expertise and motivation of the different agents and their performance as a function of self-organisation, boredom, and task rotation frequency, we describe the dynamics of task rotation. The results show that systems i...

  14. Relating hearing loss and executive functions to hearing aid users’ preference for, and speech recognition with, different combinations of binaural noise reduction and microphone directionality

    Directory of Open Access Journals (Sweden)

    Tobias eNeher

    2014-12-01

    Full Text Available Knowledge of how executive functions relate to preferred hearing aid (HA processing is sparse and seemingly inconsistent with related knowledge for speech recognition outcomes. This study thus aimed to find out if (1 performance on a measure of reading span (RS is related to preferred binaural noise reduction (NR strength, (2 similar relations exist for two different, nonverbal measures of executive function, (3 pure-tone average hearing loss (PTA, signal-to-noise ratio (SNR, and microphone directionality (DIR also influence preferred NR strength, and (4 preference and speech recognition outcomes are similar. Sixty elderly HA users took part. Six HA conditions consisting of omnidirectional or cardioid microphones followed by inactive, moderate, or strong binaural NR as well as linear amplification were tested. Outcome was assessed at fixed SNRs using headphone simulations of a frontal target talker in a busy cafeteria. Analyses showed positive effects of active NR and DIR on preference, and negative and positive effects of, respectively, strong NR and DIR on speech recognition. Also, while moderate NR was the most preferred NR setting overall, preference for strong NR increased with SNR. No relation between RS and preference was found. However, larger PTA was related to weaker preference for inactive NR and stronger preference for strong NR for both microphone modes. Equivalent (but weaker relations between worse performance on one nonverbal measure of executive function and the HA conditions without DIR were found. For speech recognition, there were relations between HA condition, PTA, and RS, but their pattern differed from that for preference. Altogether, these results indicate that, while moderate NR works well in general, a notable proportion of HA users prefer stronger NR. Furthermore, PTA and executive functions can account for some of the variability in preference for, and speech recognition with, different binaural NR and DIR settings.

  15. Developmental Dynamics between Children's Externalizing Problems, Task-Avoidant Behavior, and Academic Performance in Early School Years: A 4-Year Follow-Up

    Science.gov (United States)

    Metsäpelto, Riitta-Leena; Pakarinen, Eija; Kiuru, Noona; Poikkeus, Anna-Maija; Lerkkanen, Marja-Kristiina; Nurmi, Jari-Erik

    2015-01-01

    This longitudinal study investigated the associations among children's externalizing problems, task-avoidant behavior, and academic performance in early school years. The participants were 586 children (43% girls, 57% boys). Data pertaining to externalizing problems (teacher ratings) and task-avoidant behaviors (mother and teacher ratings) were…

  16. Short-term learning of a visually guided power-grip task is associated with dynamic changes in EEG oscillatory activity

    OpenAIRE

    Kranczioch, C.; Athanassiou, S.; Shen, S; G. Gao; A. Sterr

    2008-01-01

    Objective: Performing a motor task after a period of training has been associated with reduced cortical activity and changes in oscillatory brain activity. Little is known about whether learning also affects the neural network associated with motor preparation and post movement processes. Here we investigate how short-term motor learning affects oscillatory brain activity during the preparation, execution, and post-movement stage of a force-feedback task. Methods: Participants performed a vis...

  17. Structure-based modeling of head-related transfer functions towards interactive customization of binaural sound systems

    Science.gov (United States)

    Gupta, Navarun

    2003-10-01

    One of the most popular techniques for creating spatialized virtual sounds is based on the use of Head-Related Transfer Functions (HRTFs). HRTFs are signal processing models that represent the modifications undergone by the acoustic signal as it travels from a sound source to each of the listener's eardrums. These modifications are due to the interaction of the acoustic waves with the listener's torso, shoulders, head and pinnae, or outer ears. As such, HRTFs are somewhat different for each listener. For a listener to perceive synthesized 3-D sound cues correctly, the synthesized cues must be similar to the listener's own HRTFs. One can measure individual HRTFs using specialized recording systems, however, these systems are prohibitively expensive and restrict the portability of the 3-D sound system. HRTF-based systems also face several computational challenges. This dissertation presents an alternative method for the synthesis of binaural spatialized sounds. The sound entering the pinna undergoes several reflective, diffractive and resonant phenomena, which determine the HRTF. Using signal processing tools, such as Prony's signal modeling method, an appropriate set of time delays and a resonant frequency were used to approximate the measured Head-Related Impulse Responses (HRIRs). Statistical analysis was used to find out empirical equations describing how the reflections and resonances are determined by the shape and size of the pinna features obtained from 3D images of 15 experimental subjects modeled in the project. These equations were used to yield "Model HRTFs" that can create elevation effects. Listening tests conducted on 10 subjects show that these model HRTFs are 5% more effective than generic HRTFs when it comes to localizing sounds in the frontal plane. The number of reversals (perception of sound source above the horizontal plane when actually it is below the plane and vice versa) was also reduced by 5.7%, showing the perceptual effectiveness of this

  18. As good as the real thing? Performance differences for live versus recorded stimuli in an everyday listening task

    DEFF Research Database (Denmark)

    Kirkwood, Brent Christopher

    In an attempt to understand the influence of stimulus presentation method for a typical everyday listening task, test subject performance in a dropped-rod length-estimate experiment was compared for three cases: 1) live presentation of stimuli, 2) playback of binaural stimuli as recorded from an...... surfaces. This experiment was performed to assess the significance of the presentation technique and to better understand the underlying acoustic structure important for length perception. Normal-hearing test subjects were seated facing away from an acoustically transparent but visually opaque screen. Test...... to a just-reachable distance between it and a stationary surface. In an attempt to make the task as natural as possible, the recording, playback, and live presentation of the stimuli all occurred in the same acoustically-normal room. Recordings were made in a position typical of where the test...

  19. As good as the real thing? Performance differences for live versus recorded stimuli in an everyday listening task

    DEFF Research Database (Denmark)

    Kirkwood, Brent Christopher

    2005-01-01

    In an attempt to understand the influence of stimulus presentation method for a typical everyday listening task, test subject performance in a dropped-rod length-estimate experiment was compared for three cases: 1) live presentation of stimuli, 2) playback of binaural stimuli as recorded from an...... surfaces. This experiment was performed to assess the significance of the presentation technique and to better understand the underlying acoustic structure important for length perception. Normal-hearing test subjects were seated facing away from an acoustically transparent but visually opaque screen. Test...... to a just-reachable distance between it and a stationary surface. In an attempt to make the task as natural as possible, the recording, playback, and live presentation of the stimuli all occurred in the same acoustically-normal room. Recordings were made in a position typical of where the test...

  20. Task inhibition and task repetition in task switching

    OpenAIRE

    Philipp, A; Koch, I.

    2006-01-01

    To explore the effect of exogenous processes on cognitive control, we used a cueing task-switching paradigm with two spatial judgement tasks and added an irrelevant colour attribute to the task-relevant spatial attribute of the target. The colour was not related to any specific Stimulus-Response relation in the tasks. A correlation was created between stimulus colour and task identity. This correlation was strong but imperfect in Experiment 1 and perfect in Experiment 2. As a result of the co...

  1. A task control architecture for autonomous robots

    Science.gov (United States)

    Simmons, Reid; Mitchell, Tom

    1990-01-01

    An architecture is presented for controlling robots that have multiple tasks, operate in dynamic domains, and require a fair degree of autonomy. The architecture is built on several layers of functionality, including a distributed communication layer, a behavior layer for querying sensors, expanding goals, and executing commands, and a task level for managing the temporal aspects of planning and achieving goals, coordinating tasks, allocating resources, monitoring, and recovering from errors. Application to a legged planetary rover and an indoor mobile manipulator is described.

  2. Multi-agent tasks scheduling system in software defined networks

    International Nuclear Information System (INIS)

    In this paper a multi-agent tasks scheduling system in software defined networks is considered. This system is designed for distribution simulation and tasks implementation on computational resources including network dynamic characteristics and topology.

  3. INCIDENCIA DE TAREAS DE APRENDIZAJE EN LA DINÁMICA DEL INTERÉS. UN ESTUDIO EN EDUCACIÓN TECNOLÓGICA (INCIDENCE OF LEARNING TASKS IN THE DYNAMICS OF INTEREST. A STUDY IN TECHNOLOGICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    Hirigoyen María Amelia

    2011-04-01

    findings from a descriptive, instructional designs based on the impact of tasks considered the Science-Technology-Society-Environment (contextualized tasks and those who did not (not contextualized tasks, the dynamics of students' interest in the subject Technology Education. That is to say, we aimed to analyze and discuss whether the proposed tasks produced a greater or lesser interest in the students for their achievement. Data were collected through classroom observations, which responded to the qualitative paradigm of research, conducted in 2009. We worked with students in sixth grade, freshman and junior year and with their teachers in the city of Rio Cuarto (Cordoba, Argentina and in a nearby locality. The results confirmed that the contextualized tasks that were included in the content of technology (biotechnology, greenhouse, etc. To pose problems related to scientific, social and environmental generated interest among students. However, the study showed that contextualize the work was not always sufficient and necessary factors were linked to the promotion of interest-called situational interest factors, such as mode of presentation of tasks, explanations of the goals of the tasks and feedback on its realization, etc. Thus, we identified indicators of student interest (request for assistance, consultation questions, showing progress, permanence tasks, etc. and situational interest factors already mentioned. Consideration of situational interest and the contextualization of the tasks in the teaching of technology becomes important to promote the interests of individual students.

  4. Heuristic Based Task Scheduling In Grid

    Directory of Open Access Journals (Sweden)

    Manpreet Singh

    2012-09-01

    Full Text Available Grid computing is concerned with coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organizations. Efficient scheduling of complex applications in a grid environment reveals several challenges due to its high heterogeneity, dynamic behavior and space shared utilization. Objectives of scheduling algorithms are increase in system throughput, efficiency and reduction in task completion time. The main focus of this paper is to highlight the merits of resource and task selection technique based on certain heuristics.

  5. Sound source localization based on binaural cross-correlation functions%基于双耳互相关函数的声源定位算法

    Institute of Scientific and Technical Information of China (English)

    万新旺; 吴镇扬

    2011-01-01

    为了提高受生物启发的定位算法的定位成功率,提出了一种基于双耳互相关函数的声源定位算法.该算法包括2个阶段:离线阶段和在线阶段.在离线阶段,测量与头相关脉冲响应(HRIR),并计算所有HRIR的双耳互相关函数(BCCF).当处于在线阶段时,首先,计算接收信号的BCCF;然后,计算接收信号的BCCF与所有HRIR的BCCF之间的Pearson相关系数;最后,将最大的Pearson相关系数对应的方位作为估计的声源方位.实验结果表明,在有2个声源同时存在的情况下,相对于互通道(cross-channel)定位算法,该算法把主峰定位成功率和次峰定位成功率分别提高了约1.64%和26.48%.%To improve the successful localization rate of the biologically inspired sound source localization method, a sound source localization algorithm based on binaural cross-correlation functions is proposed. The proposed method contains two phases: offline phase and online phase. During the offline phase, the head-related impulse responses (HRIR) are measured, and the binaural cross-correlation functions (BCCF) of the HRIRs are calculated. During the online phase, first, the BCCF of the received signals is computed; then Pearson correlation coefficient between the BCCF of the received signals and that of the HRIRs are calculated; finally, the azimuth corresponding to the largest Pearson correlation coefficient is regarded as the azimuth of the sound source. The experimental results show that when two sound sources are simultaneously present, compared with the cross-channel sound source localization method, the proposed algorithm increases the successful localization rate of the main peak and that of the second peak by about 1.64% and 26.48% , respectively.

  6. Task-level control for autonomous robots

    Science.gov (United States)

    Simmons, Reid

    1994-01-01

    Task-level control refers to the integration and coordination of planning, perception, and real-time control to achieve given high-level goals. Autonomous mobile robots need task-level control to effectively achieve complex tasks in uncertain, dynamic environments. This paper describes the Task Control Architecture (TCA), an implemented system that provides commonly needed constructs for task-level control. Facilities provided by TCA include distributed communication, task decomposition and sequencing, resource management, monitoring and exception handling. TCA supports a design methodology in which robot systems are developed incrementally, starting first with deliberative plans that work in nominal situations, and then layering them with reactive behaviors that monitor plan execution and handle exceptions. To further support this approach, design and analysis tools are under development to provide ways of graphically viewing the system and validating its behavior.

  7. Multi-granularity dynamic access control model based on tasks and roles%基于任务和角色的多粒度动态访问控制模型

    Institute of Scientific and Technical Information of China (English)

    彭佳玮; 孙国强; 杨少友

    2016-01-01

    To resolve the problems existing in the traditional access control model,an improved model called multi-granularity dynamic access control model based on tasks and roles (MG-TRBAC)was present.A supervision mechanism concept was added based on the TRBAC model,roles and tasks were dynamically managed and associated to improve the rigor,security,and initia-tive of access control.To make the multi-granularity access authorization more flexible,the authorization process was decom-posed into page level,function level and data level,and a new strategy module associating with the authorization of data layer for data accessing was added.The implementation of the model in a proj ect shows that the model can effectively meet the needs of the project for access control,verifying the feasibility of the model.%对传统的访问控制模型存在的问题进行分析,提出一种基于任务和角色的多粒度动态访问控制模型 (MG-TR-BAC).在TRBAC模型基础上新增监管机制概念,通过对角色和任务进行约束管理和动态关联,提升访问控制的严密性、安全性和主动性;将授权过程分解为页面、功能、数据3个层次,新增数据访问策略模块与数据层授权关联,实现更加灵活的多粒度访问授权.项目实现结果表明,该模型能够有效满足项目对访问控制的需求,体现了模型的可行性.

  8. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  9. Doubling the task - Effects of task switching during simultaneous control of multiple airports

    OpenAIRE

    Schneider, Norbert; Moehlenbrink, Christoph; Andrea, Kiesel

    2011-01-01

    Research on remote tower control solutions for small airports raised the question whether it is possible for an air traffic controller to control multiple airports simultaneously. This simultaneous control would require the air traffic controller to switch between task sets of two airports. Therefore it is important to analyse the factors influencing task switching in these dynamic multiple task environments and how they are affecting the air traffic controller. A human-in-the-loop microwo...

  10. Launching Complex Tasks

    Science.gov (United States)

    Jackson, Kara J.; Shahan, Emily C.; Gibbons, Lynsey K.; Cobb, Paul A.

    2012-01-01

    Mathematics lessons can take a variety of formats. In this article, the authors discuss lessons organized around complex mathematical tasks. These lessons usually unfold in three phases. First, the task is introduced to students. Second, students work on solving the task. Third, the teacher "orchestrates" a concluding whole-class discussion in…

  11. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  12. Coordination and Multi-Tasking Using EMT

    OpenAIRE

    Rabinovich, Zinovi; Pochter, Nir; Rosenschein, Jeffrey S.

    2008-01-01

    We introduce a multi-model variant of the EMT-based control algorithm. The new algorithm, MM-EMT, is capable of balancing several control tasks expressed using separate dynamic models with a common action space. Such multiple models are common in both single-agent environments, when the agent has multiple tasks to achieve, and in team activities, when agent actions affect both the local agent’s task as well as the overall team’s coordination. To demonstrate the behaviour that MM-EMT engenders...

  13. Psychophysiological reactivity to auditory Binaural Beats stimulation in the alpha and theta EEG brain-wave frequency bands: A randomized, double–blind and placebo–controlled study in human healthy young adult subjects

    OpenAIRE

    Pfaff, Hans Uwe

    2014-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Psicología, Departamento de Psicología Biológica y de la Salud. Fecha de lectura: 25-06-2014 Binaural beats are an acoustical illusion of the perception of a “virtual” third tone, fluctuating (i.e. beating) in its volume evoked by two carrier–sinusoids of same amplitudes, but slightly different frequencies f1 and f2, presented by stereo-headphones. Although this illusion was discovered as early as 1839 ...

  14. Transport Task Force Leadership, Task 4

    International Nuclear Information System (INIS)

    The Transport Task Force (TTF) was initiated as a broad-based US magnetic fusion community activity during the fall of 1988 to focus attention on and encourage development of an increased understanding of anomalous transport in tokamaks. The overall TTF goal is to make progress on Characterizing, Understanding and Identifying how to Reduce plasma transport in tokamaks -- to CUIR transport

  15. A Brief Analysis of Communication Tasks in Task- based Teaehing

    Institute of Scientific and Technical Information of China (English)

    Xu Xiaoying

    2011-01-01

    Task -Based Language Teaching (TBLT) aims at proving opportunities for the learners to experiment with and explore both spoken and written language through learning activities. This passage further exam if the following four communicative tasks jigsaw tasks, role - play tasks, problem solving tasks, and information gap tasks can assist classroom learning.

  16. Brain network adaptability across task states.

    Directory of Open Access Journals (Sweden)

    Elizabeth N Davison

    2015-01-01

    Full Text Available Activity in the human brain moves between diverse functional states to meet the demands of our dynamic environment, but fundamental principles guiding these transitions remain poorly understood. Here, we capitalize on recent advances in network science to analyze patterns of functional interactions between brain regions. We use dynamic network representations to probe the landscape of brain reconfigurations that accompany task performance both within and between four cognitive states: a task-free resting state, an attention-demanding state, and two memory-demanding states. Using the formalism of hypergraphs, we identify the presence of groups of functional interactions that fluctuate coherently in strength over time both within (task-specific and across (task-general brain states. In contrast to prior emphases on the complexity of many dyadic (region-to-region relationships, these results demonstrate that brain adaptability can be described by common processes that drive the dynamic integration of cognitive systems. Moreover, our results establish the hypergraph as an effective measure for understanding functional brain dynamics, which may also prove useful in examining cross-task, cross-age, and cross-cohort functional change.

  17. Microscopic prediction of speech intelligibility in spatially distributed speech-shaped noise for normal-hearing listeners.

    Science.gov (United States)

    Geravanchizadeh, Masoud; Fallah, Ali

    2015-12-01

    A binaural and psychoacoustically motivated intelligibility model, based on a well-known monaural microscopic model is proposed. This model simulates a phoneme recognition task in the presence of spatially distributed speech-shaped noise in anechoic scenarios. In the proposed model, binaural advantage effects are considered by generating a feature vector for a dynamic-time-warping speech recognizer. This vector consists of three subvectors incorporating two monaural subvectors to model the better-ear hearing, and a binaural subvector to simulate the binaural unmasking effect. The binaural unit of the model is based on equalization-cancellation theory. This model operates blindly, which means separate recordings of speech and noise are not required for the predictions. Speech intelligibility tests were conducted with 12 normal hearing listeners by collecting speech reception thresholds (SRTs) in the presence of single and multiple sources of speech-shaped noise. The comparison of the model predictions with the measured binaural SRTs, and with the predictions of a macroscopic binaural model called extended equalization-cancellation, shows that this approach predicts the intelligibility in anechoic scenarios with good precision. The square of the correlation coefficient (r(2)) and the mean-absolute error between the model predictions and the measurements are 0.98 and 0.62 dB, respectively. PMID:26723354

  18. Task Description Language

    Science.gov (United States)

    Simmons, Reid; Apfelbaum, David

    2005-01-01

    Task Description Language (TDL) is an extension of the C++ programming language that enables programmers to quickly and easily write complex, concurrent computer programs for controlling real-time autonomous systems, including robots and spacecraft. TDL is based on earlier work (circa 1984 through 1989) on the Task Control Architecture (TCA). TDL provides syntactic support for hierarchical task-level control functions, including task decomposition, synchronization, execution monitoring, and exception handling. A Java-language-based compiler transforms TDL programs into pure C++ code that includes calls to a platform-independent task-control-management (TCM) library. TDL has been used to control and coordinate multiple heterogeneous robots in projects sponsored by NASA and the Defense Advanced Research Projects Agency (DARPA). It has also been used in Brazil to control an autonomous airship and in Canada to control a robotic manipulator.

  19. Dynamic Task Scheduling on Multicore Automotive ECUs

    OpenAIRE

    Geetishree Mishra; K.S.Gurumurthy

    2014-01-01

    Automobile manufacturers are controlled by stringen t govt. regulations for safety and fuel emissions a nd motivated towards adding more advanced features and sophisticated applications to the existing electro nic system. Ever increasing customer’s demands for high level of comfort also necessitate providing even m ore sophistication in vehicle electronics system. All t hese, directly make the vehicle software system mor e co...

  20. Dynamics of Wood Chip Storage: Task I

    Energy Technology Data Exchange (ETDEWEB)

    Sworden, P. G.

    1982-08-01

    The purpose of this report is to document Dow Corning's decision making process in establishing a fuelwood supply and procurement system with emphasis on how this relates to private forest landowners. The report will provide background on the decision to investigate wood energy systems and key management questions in that decision process. Information used to answer the key management questions will be high-lighted and its usefulness documented, including resource assessment and requirements. The report will discuss the development and implementation of the landowner assistance program and supplier-producer program. At the end of the report, Dow Corning's experiences will be summarized and some conclusions drawn concerning the success of the program.

  1. Task-Driven Dynamic Text Summarization

    Science.gov (United States)

    Workman, Terri Elizabeth

    2011-01-01

    The objective of this work is to examine the efficacy of natural language processing (NLP) in summarizing bibliographic text for multiple purposes. Researchers have noted the accelerating growth of bibliographic databases. Information seekers using traditional information retrieval techniques when searching large bibliographic databases are often…

  2. Learning one task by interleaving practice with another task

    OpenAIRE

    Szpiro, Sarit; Wright, Beverly A.; Carrasco, Marisa

    2014-01-01

    Perceptual learning is a sustainable improvement in performance on a perceptual task following training. A hallmark of perceptual learning is task specificity – after participants have trained on and learned a particular task, learning rarely transfers to another task, even with identical stimuli. Accordingly, it is assumed that performing a task throughout training is a requirement for learning to occur on that specific task. Thus, interleaving training trials of a target task, with those of...

  3. Spatial dependency between task positive and task negative networks

    OpenAIRE

    Leech, Robert; Scott, Gregory; Carhart-Harris, Robin; Turkheimer, Federico; Taylor-Robinson, Simon D; Sharp, David J.

    2013-01-01

    Functional neuroimaging reveals both increases (task-positive) and decreases (task-negative) in neural activation with many tasks. Many studies show a temporal relationship between task positive and task negative networks that is important for efficient cognitive functioning. Here we provide evidence for a spatial relationship between task positive and negative networks. There are strong spatial similarities between many reported task negative brain networks, termed the default mode network, ...

  4. Studying Different Tasks of Implicit Learning across Multiple Test Sessions Conducted on the Web

    OpenAIRE

    Sævland, Werner; Norman, Elisabeth

    2016-01-01

    Implicit learning is usually studied through individual performance on a single task, with the most common tasks being the Serial Reaction Time (SRT) task, the Dynamic System Control (DSC) task, and Artificial Grammar Learning (AGL). Few attempts have been made to compare performance across different implicit learning tasks within the same study. The current study was designed to explore the relationship between performance on the DSC Sugar factory task and the Alternating Serial Reaction Tim...

  5. Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

    OpenAIRE

    Čeko, Marta; Gracely, John L.; Fitzcharles, Mary-Ann; Seminowicz, David A.; Schweinhardt, Petra; Bushnell, M. Catherine

    2015-01-01

    In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or “negative” [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether ...

  6. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo;

    2015-01-01

    fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...... introductory to specialized, and from authoritative to speculative or opinionated, when to show what sources of information? How does the information seeking process evolve and what are relevant differences between different stages? With complex task and search process management, blending searching, browsing...

  7. Is Task-Irrelevant Learning Really Task-Irrelevant?

    OpenAIRE

    Seitz, Aaron R.; Watanabe, Takeo

    2008-01-01

    In the present study we address the question of whether the learning of task-irrelevant stimuli found in the paradigm of task-irrelevant learning (TIPL) [1]–[9] is truly task irrelevant. To test the hypothesis that associations that are beneficial to task-performance may develop between the task-relevant and task-irrelevant stimuli, or the task-responses and the task-irrelevant stimuli, we designed a new procedure in which correlations between the presentation of task-irrelevant motion stimul...

  8. Data analysis tasks: BATSE

    Science.gov (United States)

    Paciesas, William S.

    1993-01-01

    Miscellaneous tasks related to the operation of, and analysis of data from, the Burst and Transient Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) were performed. The results are summarized and relevant references are included.

  9. Rostering and Task Scheduling

    DEFF Research Database (Denmark)

    Dohn, Anders Høeg

    rostering process is non-trivial and especially when service is required around the clock, rostering may involve considerable effort from a designated planner. Therefore, in order to minimize costs and overstaffing, to maximize the utilization of available staff, and to ensure a high level of satisfaction...... among the employees, sophisticated scheduling methods are required. When approaching the day of operation, the detail level of the planning becomes finer. With a given allocation of shifts to employees, the focus is turned to tasks scheduling within those shifts. The objective is to assign as much work...... as possible to the available staff, while respecting various requirements and rules and while including possible transportation time between tasks. This thesis presents a number of industrial applications in rostering and task scheduling. The applications exist within various contexts in health care...

  10. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 3-5, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  11. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  12. Performing Task Integration

    DEFF Research Database (Denmark)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

    In the paper, we deal with how to organize work for cross-professional knowledge sharing. We do so inspired by relational coordination theory, which is affiliated with positive organizational scholarship. Relational coordination theory is constituted by a combination of relationships marked 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...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

  13. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld;

    2014-01-01

    only standard components in the prototype, the optimal light distribution for the purpose of meeting the requirements could not be obtained . The light distribution was approximated to the requirements by using combinations of different beam shaping lenses. A final product would benefit from custom...... made lenses, capable of providing the desired light distribution. The user test shows that when working with general lighti ng of 100 lx in the room the developed task lig ht with its wide light distribution provides flexibility in choosing a reading task area on the desk and provides more visibility...

  14. Assessing L2 Task Performance: Understanding Effects of Task Design

    Science.gov (United States)

    Tavakoli, Parvaneh

    2009-01-01

    The overarching aim of the research reported here was to investigate the effects of task structure and storyline complexity of oral narrative tasks on second language task performance. Participants were 60 Iranian language learners of English who performed six narrative tasks of varying degree of structure and storyline complexity in an assessment…

  15. A Daunting Task Still

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZHIPING

    2010-01-01

    @@ Despite steady economic growth for three decades, China is still a developing country facing daunting poverty alleviation tasks. According to the poverty line of 1,196 yuan ($176) per capita net income in a year set in March 2009, the country still has a poverty population of more than 40 million, mainly living in rural areas.

  16. Creating Positive Task Constraints

    Science.gov (United States)

    Mally, Kristi K.

    2006-01-01

    Constraints are characteristics of the individual, the task, or the environment that mold and shape movement choices and performances. Constraints can be positive--encouraging proficient movements or negative--discouraging movement or promoting ineffective movements. Physical educators must analyze, evaluate, and determine the effect various…

  17. Task 1 quarternary tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1994-12-31

    Activities on the task of quarternary tectonics for the Yucca Mountain Site investigations are described. Technical topics include: A preliminary reveiw of Bare Mountain Trench; A preliminary detailed lineament map of the Southwestern part of the proposed repository; A discussion on the 1994 Double Spring Flat, Nevada earthquake; and evidence for temporal clustering.

  18. Microprocessor multi-task monitor

    International Nuclear Information System (INIS)

    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

  19. Microprocessor multi-task monitor

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. The sequential logic model to solve the multi-Agent dynamic cooperative tasks of complex self-adaptive system%复杂自适应系统的MAS动态协作任务求解时序逻辑模型

    Institute of Scientific and Technical Information of China (English)

    蒋伟进; 张莲梅; 史德嘉

    2012-01-01

    借鉴组织学思想将自适应系统中的自主运行单元抽象为Agent,把复杂自适应系统视为多Agent组织,从时间和状态角度对复杂动态系统的行为进行描述,提出了基于时序活动逻辑的多Agent动态协作任务求解自适应机制和构造模型;分析了任务求解BDI Agent的信念、愿望、意图的产生过程和实现方法,建立了协商推理的语义规则和行为规则,给出了协作群组的选择算法.并从任务求解Agent的心智变化角度,描述了动态协作任务求解模型实现的六个阶段:任务动态分配、协作意愿产生、协作群体生成、共同计划制定、协作群体行动和结果评估.通过在MAGE等平台上实验和仿真测试,验证了方法的可行性和有效性.%Solving dynamic complex problem is difficult in the theory and applied research of artificial intelligence and complex adaptive systems. Idea from histology is that the auto-run unit in self-adaptive system is abstracted to be Agent, the complex adaptive system is considered as a multi-Agent tissue. The behavior of complex dynamic systems in time and space is described. The adaptive mechanisms and structure model of solving multi-Agent dynamic cooperative tasks based on sequential active logic are proposed. The production process and realization of BDI belief, desire, intention of solving task are analyzed. The semantic rules and action rules of cooperative deduction is builded. The selection algorithm of cooperative groups is given. From the mind change of task solving Agent, the paper describes the six stages to realize the solving model of dynamic cooperative tasks. The six stages are dynamic allocation of tasks, collaboration will produce, generate collaborative groups, common planning making, collaborative groups action and evaluation of results. Experiments and simulation on MAGE and other platforms prove the feasibility and effectiveness of our proposed approaches.

  1. Event Related Potentials (ERPs) in Elementary Cognitive Tasks Reflect Task Difficulty and Task Threshold.

    Science.gov (United States)

    Caryl, P. G.; Harper, Alison

    1996-01-01

    Effects on the event-related potential (ERP) waveform of differences in stimuli (task difficulty) and threshold were studied with 35 undergraduates performing a visual inspection time task and 30 performing a pitch discrimination task. In both tasks, ERP differences related to threshold were temporally localized differences in waveform shape. (SLD)

  2. Analysis of operators' diagnosis tasks based on cognitive process

    International Nuclear Information System (INIS)

    Diagnosis tasks in nuclear power plants characterized as high-dynamic uncertainties are complex reasoning tasks. Diagnosis errors are the main causes for the error of commission. Firstly, based on mental model theory and perception/action cycle theory, a cognitive model for analyzing operators' diagnosis tasks is proposed. Then, the model is used to investigate a trip event which occurred at crystal river nuclear power plant. The application demonstrates typical cognitive bias and mistakes which operators may make when performing diagnosis tasks. They mainly include the strong confirmation tendency, difficulty to produce complete hypothesis sets, group mindset, non-systematic errors in hypothesis testing, and etc. (authors)

  3. Multi-tasking and the Returns to Experience

    OpenAIRE

    Parama Chaudhury

    2010-01-01

    In this paper, I study how an increase in the use of new work practices that involve multi-tasking has affected the returns to experience.  If each task in a job has a concave learning curve, then increasing the number of tasks may increase the returns to experience.  Using the Panel Study of Income Dynamics, I provide evidence for the fact that successive cohorts have greater returns to experience.  Next, I construct proxies for multi-tasking using Paul Osterman's 1992 survey of workplace pr...

  4. PRI: An Periodically Receiver-Initiated Task Scheduling Algorithm

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Task scheduling is a key problem for the distributed computation. This thesis analyzes receiver-initiated(RI) task scheduling algorithm, finds its weakness and presents an improved algorithm-PRI algorithm. This algorithm schedules the concurrent tasks onto network of workstation dynamically at runtime, and initiates task scheduling by the node of low load. The threshold on each node can be modified according to the system information which is periodically detected. Meanwhile, the detecting period can be adjusted in terms of the change of the system state. The result of the experiments shows that the PRI algorithm is superior to the RI algorithm.

  5. Force-Field Compensation in a Manual Tracking Task

    OpenAIRE

    Valentina Squeri; Lorenzo Masia; Maura Casadio; Pietro Morasso; Elena Vergaro

    2010-01-01

    This study addresses force/movement control in a dynamic "hybrid" task: the master sub-task is continuous manual tracking of a target moving along an eight-shaped Lissajous figure, with the tracking error as the primary performance index; the slave sub-task is compensation of a disturbing curl viscous field, compatibly with the primary performance index. The two sub-tasks are correlated because the lateral force the subject must exert on the eight-shape must be proportional to the longitudina...

  6. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all......, the paper is an investigation into how various (mundane) organizing devices interact with, influence, and shape particular organizational practices which are assumed to perform the well-functioning welfare state....

  7. Task analysis and support for problem solving tasks

    International Nuclear Information System (INIS)

    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)

  8. Futures Trading: Task Analysis

    Czech Academy of Sciences Publication Activity Database

    Zeman, Jan

    Praha: UTIA AV ČR, v.v.i, - DAR, 2009 - (Janžura; Ivánek). s. 38-38 [5th International Workshop on Data – Algorithms – Decision Making. 29.11.2009-01.12.2009, Plzeň] Institutional research plan: CEZ:AV0Z10750506 Keywords : decision making * futures trading * optimization Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2009/AS/zeman-futures trading task analysis .pdf

  9. Features or tasks?

    DEFF Research Database (Denmark)

    Heilesen, Simon

    In this paper for the Workshop on Human-computer interaction and e-learning, NordiCHI 2002, the author argues that in developing innovative E-learning systems, especially if constructivist pedagogy is to be applied, it will be useful to model the user interface on the often complex tasks that the...... user has to perform rather than just focusing on technical features (and adapting system use to them)....

  10. 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.

  11. The Nexus task-parallel runtime system

    Energy Technology Data Exchange (ETDEWEB)

    Foster, I.; Tuecke, S. [Argonne National Lab., IL (United States); Kesselman, C. [Caltech, Pasadena, CA (United States). Beckman Institute

    1994-12-31

    A runtime system provides a parallel language compiler with an interface to the low-level facilities required to support interaction between concurrently executing program components. Nexus is a portable runtime system for task-parallel programming languages. Distinguishing features of Nexus include its support for multiple threads of control, dynamic processor acquisition, dynamic address space creation, a global memory model via interprocessor references, and asynchronous events. In addition, it supports heterogeneity at multiple levels, allowing a single computation to utilize different programming languages, executables, processors, and network protocols. Nexus is currently being used as a compiler target for two task-parallel languages: Fortran M and Compositional C++. In this paper, we present the Nexus design, outline techniques used to implement Nexus on parallel computers, show how it is used in compilers, and compare its performance with that of another runtime system.

  12. Mobile Thread Task Manager

    Science.gov (United States)

    Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

    2013-01-01

    The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

  13. Gap Task Force

    CERN Multimedia

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  14. Urban task force

    Directory of Open Access Journals (Sweden)

    Grubović Ljiljana V.

    2002-01-01

    Full Text Available The Urban Task Force Report has brought to our attention, that English towns and cities today require a new renaissance. The comprehensive planning has retarded urban living (Urban Renaissance, Sharing the Vision 01.99, 1999. Forty percent of inner-urban housing stock is subsidized 'social' housing. A review of the demographic and development trends have lead to the UK Government’s new urban policy that prioritizes the regeneration of towns and cities by building on recycled urban land and protecting the countryside. As result, Urban Task Force (UTF was founded the with the following aims To identify causes of urban decline in England; To recommend practical solutions how to bring people back into cities; To establish a new vision for urban regeneration based on the principles of design excellence, social well being and environmental responsibility within a viable economic and legislative framework (Urban Task Force, 1999:1. This paper represents the analysis of the economic and political effects of the program and its viability.

  15. The task force process

    International Nuclear Information System (INIS)

    This paper focuses on the unique aspects of the Fernald Citizens Task Force process that have contributed to a largely successful public participation effort at Fernald. The Fernald Citizens Task Force passed quickly by many procedural issues. Instead, the Task Force concentrated on (a) educating itself about the site, its problems, and possible solutions, and (b) choosing a directed way to approach its mandate: To make recommendations on several open-quotes big pictureclose quotes issues, including future use of the site, cleanup levels, waste disposition, and cleanup priorities. This paper presents the approach used at Fernald for establishing and running a focused site-specific advisory board, the key issues that have been faced, and how these issues were resolved. The success of Fernald in establishing a strong and functioning site-specific advisory board serves as a useful model for other DOE facilities, although the Fernald model is just one of many approaches that can be taken. However, the approach presented here has worked extremely well for Fernald

  16. Task-specific effects of reward on task switching.

    Science.gov (United States)

    Umemoto, Akina; Holroyd, Clay B

    2015-07-01

    Although cognitive control and reinforcement learning have been researched extensively over the last few decades, only recently have studies investigated their interrelationship. An important unanswered question concerns how the control system decides what task to execute and how vigorously to carry out the task once selected. Based on a recent theory of control formulated according to principles of hierarchical reinforcement learning, we asked whether rewards can affect top-down control over task performance at the level of task representation. Participants were rewarded for correctly performing only one of two tasks in a standard task-switching experiment. Reaction times and error rates were lower for the reinforced task compared to the non-reinforced task. Moreover, the switch cost in error rates for the non-reinforced task was significantly larger compared to the reinforced task, especially for trials in which the imperative stimulus afforded different responses for the two tasks, resulting in a "non-paradoxical" asymmetric switch cost. These findings suggest that reinforcement at the task level resulted in greater application of top-down control rather than in stronger stimulus-response pathways for the rewarded task. PMID:24984832

  17. Cognitive task load analysis : Allocating tasks and designing support

    OpenAIRE

    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 percentage time occupied, this theory distinguishes two load factors that affect cognitive task performance and mental effort: the level of information processing and the number of task-set switches. Re...

  18. Task Assignment Heuristics for Parallel and Distributed CFD Applications

    Science.gov (United States)

    Lopez-Benitez, Noe; Djomehri, M. Jahed; Biswas, Rupak

    2003-01-01

    This paper proposes a task graph (TG) model to represent a single discrete step of multi-block overset grid computational fluid dynamics (CFD) applications. The TG model is then used to not only balance the computational workload across the overset grids but also to reduce inter-grid communication costs. We have developed a set of task assignment heuristics based on the constraints inherent in this class of CFD problems. Two basic assignments, the smallest task first (STF) and the largest task first (LTF), are first presented. They are then systematically costs. To predict the performance of the proposed task assignment heuristics, extensive performance evaluations are conducted on a synthetic TG with tasks defined in terms of the number of grid points in predetermined overlapping grids. A TG derived from a realistic problem with eight million grid points is also used as a test case.

  19. Quarternary tectonics, Task 1

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1993-09-30

    Activities conducted for the evaluation of the geology and seismotectonics stability of Yucca Mountain as a potential site for the underground disposal of high-level radioactive wastes continued. Tasks concerned with quaternary tectonics include: scheduling of photography of Little Skull Mountain area; the collection and dating of rock varnish samples from the 1932 Cedar Mountain earthquake area for carbon 14 AMS and cation-ratio analysis; collection of samples for thermoluminescence dating from the 1932 Cedar Mountain earthquake area; mapping of the northern area of Crater Flat; and surveying of the May 17, 1993 Eureka the Valley earthquake area.

  20. Social Pressures and Task Performance

    OpenAIRE

    Shearer, Greg

    2013-01-01

    Previous research has demonstrated the impact of the actions of others on task performance – citing that both social acceptance and ostracism can increase task performance (Lustenberger & Jagacinski, 2010; Jamieson et. al., 2010). In this study, the relationship between social inclusion/ostracism and performance on a verbal comprehension task is investigated in an attempt to discover which is more potent in influencing task performance. Two forms of social conditioning are used; face-to-face ...

  1. Biology task group

    International Nuclear Information System (INIS)

    The accomplishments of the task group studies over the past year are reviewed. The purposes of biological investigations, in the context of subseabed disposal, are: an evaluation of the dose to man; an estimation of effects on the ecosystem; and an estimation of the influence of organisms on and as barriers to radionuclide migration. To accomplish these ends, the task group adopted the following research goals: (1) acquire more data on biological accumulation of specific radionuclides, such as those of Tc, Np, Ra, and Sr; (2) acquire more data on transfer coefficients from sediment to organism; (3) Calculate mass transfer rates, construct simple models using them, and estimate collective dose commitment; (4) Identify specific pathways or transfer routes, determine the rates of transfer, and make dose limit calculations with simple models; (5) Calculate dose rates to and estimate irradiation effects on the biota as a result of waste emplacement, by reference to background irradiation calculations. (6) Examine the effect of the biota on altering sediment/water radionuclide exchange; (7) Consider the biological data required to address different accident scenarios; (8) Continue to provide the basic biological information for all of the above, and ensure that the system analysis model is based on the most realistic and up-to-date concepts of marine biologists; and (9) Ensure by way of free exchange of information that the data used in any model are the best currently available

  2. Skill Components of Task Analysis

    Science.gov (United States)

    Adams, Anne E.; Rogers, Wendy A.; Fisk, Arthur D.

    2013-01-01

    Some task analysis methods break down a task into a hierarchy of subgoals. Although an important tool of many fields of study, learning to create such a hierarchy (redescription) is not trivial. To further the understanding of what makes task analysis a skill, the present research examined novices' problems with learning Hierarchical Task…

  3. Reverse-Engineering Communication Tasks

    Science.gov (United States)

    Lamber, Craig

    2004-01-01

    This article introduces an approach to planning sequences of communication tasks that require learners to become personally involved in their learning. By drawing on their own ideas and experiences, as a product of earlier tasks in a given sequence, learners generate the content and resource material on which subsequent tasks operate. The article…

  4. Task Analysis Technologies at KSC

    Science.gov (United States)

    Carstens, Deborah S.

    2003-01-01

    Project objective: (1) Form an integrated team of NASA. USA, Boeing, and Dynacs researches. (2) Create a user friendly software prototype that assists an analyst in performing a human factors process failure modes and effects analysis (HF-PFMEA). (3)Perform four task analyses on center: cargo late access task analysis (NASA/Boeing team); payload test and verification system task analysis (NASA/Boeing team); slammer cover installation operations task analysis (NASA/USA team); ATDC LOX pump acceptance test procedure task analysis (NASA/Dynacs team).

  5. Selection of maintenance tasks

    International Nuclear Information System (INIS)

    Two methodologies for maintenance task selection, Reliability Centre Maintenance (RCM) and Degradation Mode Analysis (DMA), are compared with regard to application in the nuclear industry and potential for application at CANDU nuclear power plants. RCM is the favoured one of the two methodologies. It is more thorough than DMA, is well supported within the US nuclear industry, and - with experience in application - is gaining cost effectiveness. There is interest in the use of RCM in other nations, including France and Japan, and it is already being implemented at Bruce A NGS and Bruce B NGS in Canada. DMA lags behind RCM in development and currently there is little experience to support claims of major benefits at reduced cost. Significant advantages over RCM need to be demonstrated if DMA is to gain acceptance in the nuclear industry. (author). 41 refs., 7 tabs., 8 figs

  6. AMU NEXRAD Exploitation Task

    Science.gov (United States)

    Lambert, Winifred C.; Wheeler, Mark M.

    1997-01-01

    This report documents the results of the Applied Meteorology Unit's NEXRAD Exploitation Task. The objectives of this task are to determine what radar signatures are present prior to and at the time of convection initiation, and to determine radar signatures which will help distinguish whether the ensuing convection will become severe. Radar data from the WSR-88D radar located at NWS Melbourne (WSR-88D/KMLB) were collected between June and September 1995, and 16 convective case studies were analyzed for which the radar was operating during the entire period of interest. All WSR-88D/KMLB products were scrutinized for their utility in detecting convection initiation and severe storm signatures. Through process of elimination, it was found that the 0.5 deg reflectivity product with the lowest reflectivity values displayed is the best product to monitor for convection initiation signatures. Seven meteorological features associated with the initiation of deep convection were identified: the Merritt Island and Indian River convergence zones, interlake convergence, horizontal convective rolls, the sea breeze, storm outflow boundaries, and fires. Their reflectivity values ranged from -5 to 20 dBZ. Of the three severe weather phenomena (winds greater than or equal to 50 kts, tornado, 3/4 inch hail), high wind events due to microbursts were most common in the data set. It was found that the values and trends of composite reflectivity, vertically integrated liquid, and core aspect ratio were key indicators of the potential of a cell to produce a microburst. The data were not analyzed for the other two severe weather phenomena because they rarely occurred during the data collection period. This report also includes suggestions for new WSR-88D products, summaries of ongoing research aimed at creating new products, and explicit recommended procedures for detecting convection initiation and severe storm signatures in the radar data using the currently available technology.

  7. Planning Educational Task

    OpenAIRE

    Burgos, Daniel; van Nimwegen, Christof

    2006-01-01

    Open Universiteit (Educational Technology Expertise Centre, Development Programme)(OUNL) and Utrecht Universiteit (Institute of information and computing sciences, Center for content and knowledge engineering)(UU) have carried out an experiment about user´s behaviour, adaptive learning and planning capacity facing a Management Educational Game. This game will also provide adaptive learning module with dynamic parallel feedback that will support the gaming flow and the reading of final results...

  8. Real-time multi-task operators support system

    International Nuclear Information System (INIS)

    The development in computer software and hardware technology and information processing as well as the accumulation in the design and feedback from Nuclear Power Plant (NPP) operation created a good opportunity to develop an integrated Operator Support System. The Real-time Multi-task Operator Support System (RMOSS) has been built to support the operator's decision making process during normal and abnormal operations. RMOSS consists of five system subtasks such as Data Collection and Validation Task (DCVT), Operation Monitoring Task (OMT), Fault Diagnostic Task (FDT), Operation Guideline Task (OGT) and Human Machine Interface Task (HMIT). RMOSS uses rule-based expert system and Artificial Neural Network (ANN). The rule-based expert system is used to identify the predefined events in static conditions and track the operation guideline through data processing. In dynamic status, Back-Propagation Neural Network is adopted for fault diagnosis, which is trained with the Genetic Algorithm. Embedded real-time operation system VxWorks and its integrated environment Tornado II are used as the RMOSS software cross-development. VxGUI is used to design HMI. All of the task programs are designed in C language. The task tests and function evaluation of RMOSS have been done in one real-time full scope simulator. Evaluation results show that each task of RMOSS is capable of accomplishing its functions. (authors)

  9. Towards Proactive Policies supporting Event-based Task Delegation

    OpenAIRE

    Gaaloul, Khaled; Miseldine, Philip; Charoy, François

    2009-01-01

    International audience Delegation mechanisms are receiving increasing interest from the research community. Task delegation is a mechanism that supports organisational flexibility in the human-centric workflow systems, and ensures delegation of authority in access control systems. In this paper, we consider task delegation as an advanced security mechanism supporting policy decision. We define an approach to support dynamic delegation of authority within an access control framework. The no...

  10. TRACE Project. Deliverable 3.4. Driving Task-Related Factors

    OpenAIRE

    Naing, C.; Hill, J.; Maguire, M.; Schick, S.; Eggers, A.; Pastor, C. (Carlos); Van Elslande, P.; Fouquet, K.; Banos, A.; PLAZA, J; Tomasch, E.; Hell, W.

    2008-01-01

    Rapport de recherche Driving task-related factors by definition are 'directly and causally contributing to the accident occurrence, very specific and detailed, are short-term lasting or dynamic in nature, and refer to the actual conditions of the components'. The aim was to analyse specific driving task-related factors to investigate how these type of factors affect the driver undertaking their tasks within driving. A selection of driving task-related factors were chosen and analysed using...

  11. Analysis of Brain Cognitive State for Arithmetic Task and Motor Task Using Electroencephalography Signal

    Directory of Open Access Journals (Sweden)

    R Kalpana

    2013-08-01

    Full Text Available To localize the brain dynamics for cognitive processes from EEG signature has been a challenging taskfrom last two decades. In this paper we explore the spatial-temporal correlations of brain electricalneuronal activity for cognitive task such as Arithmetic and Motor Task using 3D cortical distributionmethod. Ten healthy right handed volunteers participated in the experiment. EEG signal was acquiredduring resting state with eyes open and eyes closed; performing motor task and arithmetic calculations.The signal was then computed for three dimensional cortical distributions on realistic head model withMNI152 template using standardized low resolution brain electromagnetic tomography (sLORETA. Thiswas followed by an appropriate standardization of the current density, producing images of electricneuronal activity without localization bias. Neuronal generators responsible for cognitive state such asArithmetic Task and Motor Task were localized. The result was correlated with the previous neuroimaging(fMRI study investigation. Hence our result directed that the neuronal activity from EEG signal can bedemonstrated in cortical level with good spatial resolution. 3D cortical distribution method, thus, may beused to obtain both spatial and temporal information from EEG signal and may prove to be a significanttechnique to investigate the cognitive functions in mental health and brain dysfunctions. Also, it may behelpful for brain/human computer interfacing.

  12. 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. PMID:7760291

  13. 设计有活力的学习任务--谈职校学生学习兴趣的激发%Design a Dynamic Learning Tasks---Talk about Vocational Schools Stimulate Students Interest in Learning

    Institute of Scientific and Technical Information of China (English)

    徐兴振

    2014-01-01

    The task is to learn by an objective prerequisite and three objective elements integration, it is the precondition of teaching design, is also the process of building hardware platform and extract the valuable knowledge and skills, based on respect for students' learning behavior, meet the demand of students information, so as to stimulate students’ interest in learning.%学习任务是由一个客观前提以及三个客观要素整合而成,它是教学设计的前提,同时也是搭建硬件平台的过程并提炼出有价值的知识点与技能点,以此为基础尊重学生的学习行为,满足学生的资讯需求,从而激发学生的学习兴趣。

  14. Task Models in the Digital Ocean

    Science.gov (United States)

    DiCerbo, Kristen E.

    2014-01-01

    The Task Model is a description of each task in a workflow. It defines attributes associated with that task. The creation of task models becomes increasingly important as the assessment tasks become more complex. Explicitly delineating the impact of task variables on the ability to collect evidence and make inferences demands thoughtfulness from…

  15. Task Switching: A PDP Model

    Science.gov (United States)

    Gilbert, Sam J.; Shallice, Tim

    2002-01-01

    When subjects switch between a pair of stimulus-response tasks, reaction time is slower on trial N if a different task was performed on trial N--1. We present a parallel distributed processing (PDP) model that simulates this effect when subjects switch between word reading and color naming in response to Stroop stimuli. Reaction time on "switch…

  16. Cosmetology Series. Duty Task List.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains the occupational duty/task lists for three occupations in the cosmetology series. Each occupation is divided into a number of duties. A separate page for each duty in the occupation lists the tasks in that duty along with its code number and columns to indicate whether that particular duty has been taught and to provide…

  17. A Synthetic Heuristic Algorithm for Independent Task Scheduling in Cloud Systems

    Directory of Open Access Journals (Sweden)

    Arash Ghorbannia Delavar

    2011-11-01

    Full Text Available In this paper, we present a synthetic method based on genetic algorithm, for independent task scheduling in cloud computing systems. Task scheduling is a major issue in large-scale distributed systems that impresses on system performance. For some reasons such as heterogeneous and dynamic features in cloud environment, task scheduling has appeared as a NP-complete problem. Our proposed algorithm (SHIS, by some goal oriented operations such as, making an optimize initial population, dual step evaluation, and also, running the tasks by a special ordering considering resource load balancing and quality of service, achieves the optimize makespan. It also decreases the probability of task failure rate on running, based on the resource failure frequency rate, and also decreases the task starvation problem. It supports the scheduling for new entered tasks in system by a dynamic method. The experimental results show that the proposed method solution is better than the other studied algorithms.

  18. The Pragian-Emsian strata of Kitab Reserve and Barrandian Area: The 2008 SDS research task on magnetic susceptibility logs and their stratigraphic correlation by means of the dynamic time warping techniques

    Czech Academy of Sciences Publication Activity Database

    Hladil, Jindřich; Vondra, Martin; Slavík, Ladislav; Koptíková, Leona; Čejchan, Petr; Vích, Robert

    -, č. 26 (2011), s. 54-56. ISSN 2074-7268 R&D Projects: GA AV ČR IAAX00130702 Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z20670512 Keywords : dynamic time warping * magnetic suscpetibility * stratigraphy * Lower Devonian Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://unica2.unica.it/sds/images/SDS26%20-%202011.pdf

  19. Concert halls with strong lateral reflections enhance musical dynamics.

    Science.gov (United States)

    Pätynen, Jukka; Tervo, Sakari; Robinson, Philip W; Lokki, Tapio

    2014-03-25

    One of the most thrilling cultural experiences is to hear live symphony-orchestra music build up from a whispering passage to a monumental fortissimo. The impact of such a crescendo has been thought to depend only on the musicians' skill, but here we show that interactions between the concert-hall acoustics and listeners' hearing also play a major role in musical dynamics. These interactions contribute to the shoebox-type concert hall's established success, but little prior research has been devoted to dynamic expression in this three-part transmission chain as a complete system. More forceful orchestral playing disproportionately excites high frequency harmonics more than those near the note's fundamental. This effect results in not only more sound energy, but also a different tone color. The concert hall transmits this sound, and the room geometry defines from which directions acoustic reflections arrive at the listener. Binaural directional hearing emphasizes high frequencies more when sound arrives from the sides of the head rather than from the median plane. Simultaneously, these same frequencies are emphasized by higher orchestral-playing dynamics. When the room geometry provides reflections from these directions, the perceived dynamic range is enhanced. Current room-acoustic evaluation methods assume linear behavior and thus neglect this effect. The hypothesis presented here is that the auditory excitation by reflections is emphasized with an orchestra forte most in concert halls with strong lateral reflections. The enhanced dynamic range provides an explanation for the success of rectangularly shaped concert-hall geometry. PMID:24591584

  20. The Adaptation of Dynamic Test Using the Inventory of Piaget's Developmental Task (IPDT): An Initial Validation and Application%“儿童认知发展水平诊断工具”动态测验的初步编制与应用

    Institute of Scientific and Technical Information of China (English)

    张丽锦; 陈亮; 方富熹

    2011-01-01

    To understand children's cognitive development, there is an increasing need for developing and validating assessment and diagnostic methods in both research and education practices. The conventional static tests focus on a particular state of ability development, rather than children's potential ability. Building on Vygotsky's concept of "Zone of Proximal Development (ZPD)", dynamic testing has the potential to detect latent capacity of development, thus providing a way to more comprehensively assess children's cognitive capacity. Most of dynamic tests were usually adaptations of classical intelligence test tasks, exploring children's latent capacity by dynamic assessment method. So, the purpose of the current study was to develop and standardize a new dynamic test based on conservation and relation domain assessment adapted from the Inventory of Piaget's Developmental Tasks (IPDT), and to examine the validity of this new dynamic test with a sample of children with relatively low academic achievement.To validate the new dynamic test, fifty-four eight or nine years old children were randomly selected from the third grade in two public elementary schools. The dynamic testing involved four stages: pretest, intervention, modifiable, and posttest; each with a different set of testing questions. In accordance with their test performance, the participants also received six different levels of clues, developed based on theories of cognitive development as well as prior dynamic tests in other domains. The results showed that with the incremental steps of intervention in response children's performance, their performance gradually improved, providing some initial evidence for the validity of this new test.The validated dynamic test was first administered to two groups of eight and nine years old children: theexperimental group (n = 35) children with relatively lower academic achievement, and the control group (n = 33) with relatively moderate levels of academic achievement

  1. 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.

  2. Computer-Related Task Performance

    DEFF Research Database (Denmark)

    Longstreet, Phil; Xiao, Xiao; Sarker, Saonee

    2016-01-01

    's CSE is often a cumbersome process. Thus, we introduce the theoretical concept of self-prophecy (SP) and examine how this social influence strategy can be used to improve computer-related task performance. Two experiments are conducted to examine the influence of SP on task performance. Results show......The existing information system (IS) literature has acknowledged computer self-efficacy (CSE) as an important factor contributing to enhancements in computer-related task performance. However, the empirical results of CSE on performance have not always been consistent, and increasing an individual...

  3. Multiple paths in complex tasks

    Science.gov (United States)

    Galanter, Eugene; Wiegand, Thomas; Mark, Gloria

    1987-01-01

    The relationship between utility judgments of subtask paths and the utility of the task as a whole was examined. The convergent validation procedure is based on the assumption that measurements of the same quantity done with different methods should covary. The utility measures of the subtasks were obtained during the performance of an aircraft flight controller navigation task. Analyses helped decide among various models of subtask utility combination, whether the utility ratings of subtask paths predict the whole tasks utility rating, and indirectly, whether judgmental models need to include the equivalent of cognitive noise.

  4. Employee Involvement, Technology and Job Tasks

    OpenAIRE

    Green, Francis

    2009-01-01

    Using new job requirements data for Britain I show that there has been a rise in various forms of communication tasks: influencing and literacy tasks have grown especially fast, as have self-planning tasks. External communication tasks, and numerical tasks have also become more important, but physical tasks have largely remained unchanged. Although the classification of tasks as programmable or otherwise is found to be problematic, computer use accounts for much of the changed use of generic ...

  5. Task preparation processes related to reward prediction precede those related to task-difficulty expectation

    Science.gov (United States)

    Schevernels, Hanne; Krebs, Ruth M.; Santens, Patrick; Woldorff, Marty G.; Boehler, C. Nico

    2013-01-01

    Recently, attempts have been made to disentangle the neural underpinnings of preparatory processes related to reward and attention. Functional magnetic resonance imaging (fMRI) research showed that neural activity related to the anticipation of reward and to attentional demands invokes neural activity patterns featuring large-scale overlap, along with some differences and interactions. Due to the limited temporal resolution of fMRI, however, the temporal dynamics of these processes remain unclear. Here, we report an event-related potentials (ERP) study in which cued attentional demands and reward prospect were combined in a factorial design. Results showed that reward prediction dominated early cue processing, as well as the early and later parts of the contingent negative variation (CNV) slow-wave ERP component that has been associated with task-preparation processes. Moreover these reward-related electrophysiological effects correlated across participants with response-time speeding on reward-prospect trials. In contrast, cued attentional demands affected only the later part of the CNV, with the highest amplitudes following cues predicting high-difficulty potential-reward targets, thus suggesting maximal task preparation when the task requires it and entails reward prospect. Consequently, we suggest that task-preparation processes triggered by reward can arise earlier, and potentially more directly, than strategic top-down aspects of preparation based on attentional demands. PMID:24064071

  6. Task-space sensory feedback control of robot manipulators

    CERN Document Server

    Cheah, Chien Chern

    2015-01-01

    This book presents recent advances in robot control theory on task space sensory feedback control of robot manipulators. By using sensory feedback information, the robot control systems are robust to various uncertainties in modelling and calibration errors of the sensors. Several sensory task space control methods that do not require exact knowledge of either kinematics or dynamics of robots, are presented. Some useful methods such as approximate Jacobian control, adaptive Jacobian control, region control and multiple task space regional feedback are included. These formulations and methods give robots a high degree of flexibility in dealing with unforeseen changes and uncertainties in its kinematics and dynamics, which is similar to human reaching movements and tool manipulation. It also leads to the solution of several long-standing problems and open issues in robot control, such as force control with constraint uncertainty, control of multi-fingered robot hand with uncertain contact points, singularity i...

  7. Microgravity Science and Applications Program tasks, 1987 revision

    Science.gov (United States)

    1988-01-01

    A compilation is presented of the active research tasks as of the end of the FY87 of the Microgravity Science and Applications Program, NASA-Office of Space Science and Applications, involving several NASA centers and other organizations. An overview is provided of the program scope for managers and scientists in industry, university, and government communities. An introductory description is provided of the program along with the strategy and overall goal, identification of the organizational structures and people involved, and a description of each task. A list of recent publications is also provided. The tasks are grouped into six major categories: Electronic Materials; Solidification of Metals, Alloys, and Composites; Fluid Dynamics and Transport Phenomena; Biotechnology; Glasses and Ceramics; and Combustion. Other categories include Experimental Technology, General Studies and Surveys; Foreign Government Affiliations; Industrial Affiliations; and Physics and Chemistry Experiments (PACE). The tasks are divided into ground based and flight experiments.

  8. Microgravity Science and Applications Program tasks, 1990 revision

    Science.gov (United States)

    1991-01-01

    The active research tasks as of the end of the fiscal year 1990 sponsored by the Microgravity Science and Applications Division of the NASA Office of Space Science and Applications are compiled. The purpose is to provide an overview of the program scope for managers and scientists in industry, university, and government communities. The report includes an introductory description of the program, the strategy and overall goal; an index of principle investigators; and a description of each task. A list of recent publications is also provided. The tasks are grouped into six major categories: electronic materials; solidification of metals, alloys, and composites; fluid dynamics and transport phenomena; biotechnology; glasses and ceramics; combustion; experimental technology; facilities; and Physics And Chemistry Experiments (PACE). The tasks are divided into ground-based and flight experiments.

  9. Microgravity Science and Applications Program tasks, 1988 revision

    Science.gov (United States)

    1989-01-01

    The active research tasks as of the end of the fiscal year 1988 of the Microgravity Science and Applications Program, NASA-Office of Space Science and Applications, involving several NASA centers and other organizations are compiled. The purpose is to provide an overview of the program scope for managers and scientists in industry, university, and government communities. Also included are an introductory description of the program, the strategy and overall goal, identification of the organizational structures and people involved, and a description of each task. A list of recent publications is provided. The tasks are grouped into six major categories: electronic materials; solidification of metals, alloys, and composites; fluid dynamics and transport phenomena; biotechnology; glasses and ceramics; and combustion. Other categories include experimental technology, general studies and surveys; foreign government affiliations; industrial affiliations; and Physics And Chemistry Experiments (PACE). The tasks are divided into ground-based and flight experiments.

  10. Transfer of training from one working memory task to another: behavioural and neural evidence

    OpenAIRE

    Beatty, Erin L.; Oshin Vartanian

    2015-01-01

    N-back working memory (WM) tasks necessitate the maintenance and updating of dynamic rehearsal sets during performance. The delayed matching-to-sample (dMTS) task is another WM task, which in turn involves the encoding, maintenance, and retrieval of stimulus representations in sequential order. Because both n-back and dMTS engage WM function, we hypothesized that compared to a control task not taxing WM, training on the n-back task would be associated with better performance on dMTS by virtue...

  11. Task Analysis of Shuttle Entry and Landing Activities

    Science.gov (United States)

    Holland, Albert W.; Vanderark, Stephen T.

    1993-01-01

    The Task Analysis of Shuttle Entry and Landing (E/L) Activities documents all tasks required to land the Orbiter following an STS mission. In addition to analysis of tasks performed, task conditions are described, including estimated time for completion, altitude, relative velocity, normal and lateral acceleration, location of controls operated or monitored, and level of g's experienced. This analysis precedes further investigations into potential effects of zero g on piloting capabilities for landing the Orbiter following long-duration missions. This includes, but is not limited to, researching the effects of extended duration missions on piloting capabilities. Four primary constraints of the analysis must be clarified: (1) the analysis depicts E/L in a static manner--the actual process is dynamic; (2) the task analysis was limited to a paper analysis, since it was not feasible to conduct research in the actual setting (i.e., observing or filming duration an actual E/L); (3) the tasks included are those required for E/L during nominal, daylight conditions; and (4) certain E/L tasks will vary according to the flying style of each commander.

  12. Integrating Task and Data Parallelism

    OpenAIRE

    Massingill, Berna

    1993-01-01

    Many models of concurrency and concurrent programming have been proposed; most can be categorized as either task-parallel (based on functional decomposition) or data-parallel (based on data decomposition). Task-parallel models are most effective for expressing irregular computations; data-parallel models are most effective for expressing regular computations. Some computations, however, exhibit both regular and irregular aspects. For such computations, a better programming model is one that i...

  13. SENSEVAL-2 Japanese Translation Task

    OpenAIRE

    Kurohashi, Sadao; Uchimoto, Kiyotaka

    2003-01-01

    This paper describes the Senseval-2 Japanese translation task. In this task, word senses are defined according to distinct translations in a given target language. A translation memory (TM) was constructed which contains, for each Japanese head word, a list of typical Japanese expressions and their English translations. For each test word instance, participants were required to submit the TM record best approximating that usage, or alternatively, actual target word translations. There were 9 ...

  14. Annual Progress report - General Task

    Energy Technology Data Exchange (ETDEWEB)

    Wesnousky, S.G.

    1993-09-30

    This report provides a summary of progress for the project {open_quotes}Evaluation of the Geologic Relations and Seismotectonic Stability of the Yucca Mountain Area, Nevada Nuclear Waste Site Investigation (NNWSI).{close_quotes} A similar report was previously provided for the period of 1 October 1991 to 30 September 1992. The report initially covers the activities of the General Task and is followed by sections that describe the progress of the other ongoing tasks.

  15. Adaptive Algorithm For Identification Of The Environment Parameters In Contact Tasks

    International Nuclear Information System (INIS)

    An adaptive algorithm for identification of the unknown parameters of the dynamic environment in contact tasks is proposed in this paper using the augmented least square estimation method. An approximate environment digital simulator for the continuous environment dynamics is derived, i.e. a discrete transfer function which has the approximately the same characteristics as the continuous environment dynamics is found. For solving this task a method named hold equivalence is used. The general model of the environment dynamics is given and the case when the environment dynamics is represented by second order models with parameter uncertainties is considered. (Author)

  16. Age-related Multiscale Changes in Brain Signal Variability in Pre-task versus Post-task Resting-state EEG.

    Science.gov (United States)

    Wang, Hongye; McIntosh, Anthony R; Kovacevic, Natasa; Karachalios, Maria; Protzner, Andrea B

    2016-07-01

    Recent empirical work suggests that, during healthy aging, the variability of network dynamics changes during task performance. Such variability appears to reflect the spontaneous formation and dissolution of different functional networks. We sought to extend these observations into resting-state dynamics. We recorded EEG in young, middle-aged, and older adults during a "rest-task-rest" design and investigated if aging modifies the interaction between resting-state activity and external stimulus-induced activity. Using multiscale entropy as our measure of variability, we found that, with increasing age, resting-state dynamics shifts from distributed to more local neural processing, especially at posterior sources. In the young group, resting-state dynamics also changed from pre- to post-task, where fine-scale entropy increased in task-positive regions and coarse-scale entropy increased in the posterior cingulate, a key region associated with the default mode network. Lastly, pre- and post-task resting-state dynamics were linked to performance on the intervening task for all age groups, but this relationship became weaker with increasing age. Our results suggest that age-related changes in resting-state dynamics occur across different spatial and temporal scales and have consequences for information processing capacity. PMID:26942319

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

    OpenAIRE

    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 se...

  18. Human capital accumulation and the transition from specialization to multi-tasking

    OpenAIRE

    Boucekkine, Raouf; Crifo, Patricia

    2003-01-01

    This paper provides theoretical foundations to the contemporaneous increase in computer usage, human capital and multi-tasking observed in many OECD countries during the 1990s. The links between work organization, technology and human capital is modelled by establishing the conditions under which firms allocate the workers time among several productive tasks. Organizational change is then analysed in a dynamic perspective as the transition from specialization towards multi-tasking emphasizing...

  19. Human Capital Accumulation and the Transition from Specialisation to Multi-tasking

    OpenAIRE

    Raouf, BOUCEKKINE; Patricia, CRIFO

    2003-01-01

    This paper provides theoretical foundations to the contemporaneous increase in computer usage, human capital and multi-tasking observed in many OECD countries during the 1990s. The links between work organization, technology and human capital is modelled by establishing the conditions under which firms allocate the workers’ time among several productive tasks. Organizational change is then analysed in a dynamic perspective as the transition from specialization towards multi-tasking emphasizin...

  20. Capability-based task allocation in emergency-response environments: a coalition-formation approach

    OpenAIRE

    FATEMI, Afsaneh; Zamanifar, Kamran; NEMATBAKHSH, Naser

    2013-01-01

    This paper addresses coalition formation, based on agent capabilities, centered on task allocation in emergency-response environments (EREs). EREs are environments that need fast task completion as their main requirement. We propose a team-based organization model, based on an existing organization model for adaptive complex systems. The model has some key characteristics that are beneficial for EREs: agents act in dynamic, open domains; agents collaborate in completing group tasks;...

  1. Graphical programming of telerobotic tasks

    International Nuclear Information System (INIS)

    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

  2. Novice supervisors' tasks and training

    DEFF Research Database (Denmark)

    Nielsen, Jan; Jacobsen, Claus Haugaard; Mathiesen, Birgit Bork

    2012-01-01

    The debut as a clinical supervisor is still rather unknown. The aim of this study is to explore what kind of tasks novice supervisors undertake and how they are prepared for these. During 2009–2010, 350 Danish clinical psychologists have responded to the Development of Psychotherapists Common Core...... Questionnaire covering a wide range of items on professional development, experience, and practice. In this paper we focus on background data (experience, training and practice), specifically the tasks and training of the respondents as novice supervisors. The results show, that a majority of novice supervisors...... were confronted with complicated jobs, e.g., group, internal and interdisciplinary supervision, but were not prepared, i.e. trained, prior to these tasks. These findings imply that more training is needed for novice supervisors. Preferably, this training should be introduced before, or at least...

  3. Number & operations task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the number & operations concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are problems involving place value, fractions, addition, subtraction and using money. The combined task & drill sheets offer spac

  4. Improving load balance with flexibly assignable tasks

    Energy Technology Data Exchange (ETDEWEB)

    Pinar, Ali; Hendrickson, Bruce

    2003-09-09

    In many applications of parallel computing, distribution ofthe data unambiguously implies distribution of work among processors. Butthere are exceptions where some tasks can be assigned to one of severalprocessors without altering the total volume of communication. In thispaper, we study the problem of exploiting this flexibility in assignmentof tasks to improve load balance. We first model the problem in terms ofnetwork flow and use combinatorial techniques for its solution. Ourparametric search algorithms use maximum flow algorithms for probing on acandidate optimal solution value. We describe two algorithms to solve theassignment problem with \\logW_T and vbar P vbar probe calls, w here W_Tand vbar P vbar, respectively, denote the total workload and number ofproce ssors. We also define augmenting paths and cuts for this problem,and show that anyalgorithm based on augmenting paths can be used to findan optimal solution for the task assignment problem. We then consideracontinuous version of the problem, and formulate it as a linearlyconstrained optimization problem, i.e., \\min\\|Ax\\|_\\infty,\\; {\\rms.t.}\\;Bx=d. To avoid solving an intractable \\infty-norm optimization problem,we show that in this case minimizing the 2-norm is sufficient to minimizethe \\infty-norm, which reduces the problem to the well-studiedlinearly-constrained least squares problem. The continuous version of theproblem has the advantage of being easily amenable to parallelization.Our experiments with molecular dynamics and overlapped domaindecomposition applications proved the effectiveness of our methods withsignificant improvements in load balance. We also discuss how ourtechniques can be enhanced for heterogeneous systems.

  5. Human interaction with an intelligent computer in multi-task situations

    Science.gov (United States)

    Rouse, W. B.

    1975-01-01

    A general formulation of human decision making in multiple task situations is presented. It includes a description of the state, event, and action space in which the multiple task supervisor operates. A specific application to a failure detection and correction situation is discussed and results of a simulation experiment presented. Issues considered include static vs. dynamic allocation of responsibility and competitive vs. cooperative intelligence.

  6. Force-field compensation in a manual tracking task.

    Directory of Open Access Journals (Sweden)

    Valentina Squeri

    Full Text Available This study addresses force/movement control in a dynamic "hybrid" task: the master sub-task is continuous manual tracking of a target moving along an eight-shaped Lissajous figure, with the tracking error as the primary performance index; the slave sub-task is compensation of a disturbing curl viscous field, compatibly with the primary performance index. The two sub-tasks are correlated because the lateral force the subject must exert on the eight-shape must be proportional to the longitudinal movement speed in order to perform a good tracking. The results confirm that visuo-manual tracking is characterized by an intermittent control mechanism, in agreement with previous work; the novel finding is that the overall control patterns are not altered by the presence of a large deviating force field, if compared with the undisturbed condition. It is also found that the control of interaction-forces is achieved by a combination of arm stiffness properties and direct force control, as suggested by the systematic lateral deviation of the trajectories from the nominal path and the comparison between perturbed trials and catch trials. The coordination of the two sub-tasks is quickly learnt after the activation of the deviating force field and is achieved by a combination of force and the stiffness components (about 80% vs. 20%, which is a function of the implicit accuracy of the tracking task.

  7. Task management in the new ATLAS production system

    International Nuclear Information System (INIS)

    This document describes the design of the new Production System of the ATLAS experiment at the LHC [1]. The Production System is the top level workflow manager which translates physicists' needs for production level processing and analysis into actual workflows executed across over a hundred Grid sites used globally by ATLAS. As the production workload increased in volume and complexity in recent years (the ATLAS production tasks count is above one million, with each task containing hundreds or thousands of jobs) there is a need to upgrade the Production System to meet the challenging requirements of the next LHC run while minimizing the operating costs. In the new design, the main subsystems are the Database Engine for Tasks (DEFT) and the Job Execution and Definition Interface (JEDI). Based on users' requests, DEFT manages inter-dependent groups of tasks (Meta-Tasks) and generates corresponding data processing workflows. The JEDI component then dynamically translates the task definitions from DEFT into actual workload jobs executed in the PanDA Workload Management System [2]. We present the requirements, design parameters, basics of the object model and concrete solutions utilized in building the new Production System and its components.

  8. SitLog: A Programming Language for Service Robot Tasks

    Directory of Open Access Journals (Sweden)

    Luis A. Pineda

    2013-10-01

    Full Text Available In this paper we present SitLog: a declarative situation-oriented logical language for programming situated service robot tasks. The formalism is task and domain independent, and can be used in a wide variety of settings. SitLog can also be seen as a behaviour engineering specification and interpretation formalism to support action selection by autonomous agents during the execution of complex tasks. The language combines the recursive transition network formalism, extended with functions to express dynamic and contextualized task structures, with a functional language to express control and content information. The SitLog interpreter is written in Prolog and SitLog’s programs follow closely the Prolog notation, permitting the declarative specification and direct interpretation of complex applications in a modular and compact form. We discuss the structure and representation of service robot tasks in practical settings and how these can be expressed in SitLog. The present framework has been tested in the service robot Golem-II+ using the specification and programming of the typical tasks which require completion in the RoboCup@Home Competition.

  9. ELIRF at MEDIAEVAL 2013: Spoken Web Search Task

    OpenAIRE

    Gómez Adrian, Jon Ander; Hurtado Oliver, Lluis Felip; Calvo Lance, Marcos; Sanchís Arnal, Emilio

    2013-01-01

    In this paper, we present the systems that the Natural Lan- guage Engineering and Pattern Recognition group (ELiRF) has submitted to the MediaEval 2013 Spoken Web Search task. All of them are based on a Subsequence Dynamic Time Warping algorithm and are zero-resources systems. Spanish Government [TIN2011-28169-C05] FPU [ AP2010-4193] Gómez Adrian, JA.; Hurtado Oliver, LF.; Calvo Lance, M.; Sanchís Arnal, E. (2013). ELIRF at MEDIAEVAL 2013: Spoken Web Search Task. Multimed...

  10. Task-driven dictionary learning.

    Science.gov (United States)

    Mairal, Julien; Bach, Francis; Ponce, Jean

    2012-04-01

    Modeling data with linear combinations of a few elements from a learned dictionary has been the focus of much recent research in machine learning, neuroscience, and signal processing. For signals such as natural images that admit such sparse representations, it is now well established that these models are well suited to restoration tasks. In this context, learning the dictionary amounts to solving a large-scale matrix factorization problem, which can be done efficiently with classical optimization tools. The same approach has also been used for learning features from data for other purposes, e.g., image classification, but tuning the dictionary in a supervised way for these tasks has proven to be more difficult. In this paper, we present a general formulation for supervised dictionary learning adapted to a wide variety of tasks, and present an efficient algorithm for solving the corresponding optimization problem. Experiments on handwritten digit classification, digital art identification, nonlinear inverse image problems, and compressed sensing demonstrate that our approach is effective in large-scale settings, and is well suited to supervised and semi-supervised classification, as well as regression tasks for data that admit sparse representations. PMID:21808090

  11. Interpretation Tasks for Grammar Teaching.

    Science.gov (United States)

    Ellis, Rod

    1995-01-01

    The traditional approach to grammar teaching provides learners with opportunities to produce specific grammatical structures. This article explores an alternative approach, one based on interpreting input. The rationale for the approach is discussed, as are the principles for designing interpretation tasks for grammar teaching. (Contains 35…

  12. Solution of mine hydrogeology tasks

    International Nuclear Information System (INIS)

    Solution of mine hydrogeology tasks, by complexing natural isotope and man-made indicator methods in combination with traditional hydrogeologic, hydrogeochemical and geophysical studies is considered. Examples of studying water inflows to quarry and tunnel by determination of isotope composition and a complex of isotope-indicator methods respectively are presented. 48 refs.; 74 figs.; 22 tabs

  13. Use cases versus task descriptions

    DEFF Research Database (Denmark)

    Lauesen, Søren; Kuhail, Mohammad Amin

    2011-01-01

    without specifying a dialog. [Contribution] It turned out that the traditional use cases covered the customer's needs poorly in areas where improvement was important but diffi-cult. Use cases also restricted the solution space severely. Tasks didn't have these problems and allowed an easy comparison...

  14. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  15. 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 ...

  16. A framework for cognitive task analysis in systems design

    International Nuclear Information System (INIS)

    The present rapid development if advanced information technology and its use for support of operators of complex technical systems are changing the content of task analysis towards the analysis of mental activities in decision making. Automation removes the humans from routine tasks, and operators are left with disturbance control and critical diagnostic tasks, for which computers are suitable for support, if it is possible to match the computer strategies and interface formats dynamically to the requirements of the current task by means of an analysis of the cognitive task. Such a cognitive task analysis will not aim at a description of the information processes suited for particular control situations. It will rather aim at an analysis in order to identify the requirements to be considered along various dimensions of the decision tasks, in order to give the user - i.e. a decision maker - the freedom to adapt his performance to system requirements in a way which matches his process resources and subjective preferences. To serve this purpose, a number of analyses at various levels are needed to relate the control requirements of the system to the information processes and to the processing resources offered by computers and humans. The paper discusses the cognitive task analysis in terms of the following domains: The problem domain, which is a representation of the functional properties of the system giving a consistent framework for identification of the control requirements of the system; the decision sequences required for typical situations; the mental strategies and heuristics which are effective and acceptable for the different decision functions; and the cognitive control mechanisms used, depending upon the level of skill which can/will be applied. Finally, the end-users' criteria for choice of mental strategies in the actual situation are considered, and the need for development of criteria for judging the ultimate user acceptance of computer support is

  17. Masonry: Task Analyses. Competency-Based Education.

    Science.gov (United States)

    Henrico County Public Schools, Glen Allen, VA. Virginia Vocational Curriculum Center.

    These task analyses are designed to be used in combination with the "Trade and Industrial Education Service Area Resource" in order to implement competency-based education in the masonry program in Virginia. The task analysis document contains the task inventory, suggested task sequence lists, and content outlines for the secondary courses Masonry…

  18. Cosmetology: Task Analyses. Competency-Based Education.

    Science.gov (United States)

    Henrico County Public Schools, Glen Allen, VA. Virginia Vocational Curriculum Center.

    These task analyses are designed to be used in combination with the "Trade and Industrial Education Service Area Resource" in order to implement competency-based education in the cosmetology program in Virginia. The task analysis document contains the task inventory, suggested task sequence lists, and content outlines for the secondary courses…

  19. A Convex Formulation for Learning Task Relationships in Multi-Task Learning

    CERN Document Server

    Zhang, Yu

    2012-01-01

    Multi-task learning is a learning paradigm which seeks to improve the generalization performance of a learning task with the help of some other related tasks. In this paper, we propose a regularization formulation for learning the relationships between tasks in multi-task learning. This formulation can be viewed as a novel generalization of the regularization framework for single-task learning. Besides modeling positive task correlation, our method, called multi-task relationship learning (MTRL), can also describe negative task correlation and identify outlier tasks based on the same underlying principle. Under this regularization framework, the objective function of MTRL is convex. For efficiency, we use an alternating method to learn the optimal model parameters for each task as well as the relationships between tasks. We study MTRL in the symmetric multi-task learning setting and then generalize it to the asymmetric setting as well. We also study the relationships between MTRL and some existing multi-task ...

  20. A microprocessor multi-task monitor

    International Nuclear Information System (INIS)

    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 millisecond

  1. Public venture capital in Germany: task force or forced task?

    OpenAIRE

    Schilder, Dirk

    2006-01-01

    This paper deals with the question of whether public venture capital (VC) is performing its task properly, taking a look at how public VC companies' selection process, investment behavior, and consulting services reflect goals that differ from those of private VC firms. The results present evidence that public VC firms deliver a different market segment than their private counterparts; for example, their selection process and syndication behavior reveal their predominant goal of promoting the...

  2. Working-Memory Load and Temporal Myopia in Dynamic Decision Making

    Science.gov (United States)

    Worthy, Darrell A.; Otto, A. Ross; Maddox, W. Todd

    2012-01-01

    We examined the role of working memory (WM) in dynamic decision making by having participants perform decision-making tasks under single-task or dual-task conditions. In 2 experiments participants performed dynamic decision-making tasks in which they chose 1 of 2 options on each trial. The decreasing option always gave a larger immediate reward…

  3. Distractor onset but not preparation time affects the frequency of task confusions in task switching

    OpenAIRE

    Steinhauser, Marco; Gade, Miriam

    2015-01-01

    When participants rapidly switch between tasks that share the same stimuli and responses, task confusions (i.e., the accidental application of the wrong task) can occur. The present study investigated whether these task confusions result from failures of endogenous control (i.e., from ineffective task preparation) or from failures of exogenous control (i.e., from stimulus-induced task conflicts). The frequency of task confusions was estimated by considering the relative proportion of distract...

  4. Task Selection for Bandit-Based Task Assignment in Heterogeneous Crowdsourcing

    OpenAIRE

    Zhang, Hao; Sugiyama, Masashi

    2015-01-01

    Task selection (picking an appropriate labeling task) and worker selection (assigning the labeling task to a suitable worker) are two major challenges in task assignment for crowdsourcing. Recently, worker selection has been successfully addressed by the bandit-based task assignment (BBTA) method, while task selection has not been thoroughly investigated yet. In this paper, we experimentally compare several task selection strategies borrowed from active learning literature, and show that the ...

  5. Stochastic tasks: difficulty and Levin search

    OpenAIRE

    Hernández Orallo, José

    2015-01-01

    We establish a setting for asynchronous stochastic tasks that account for episodes, rewards and responses, and, most especially, the computational complexity of the algorithm behind an agent solving a task. This is used to determine the difficulty of a task as the (logarithm of the) number of computational steps required to acquire an acceptable policy for the task, which includes the exploration of policies and their verification. We also analyse instance difficulty, task c...

  6. Evaluating the Semantic Web: A Task-Based Approach

    Science.gov (United States)

    Sabou, Marta; Gracia, Jorge; Angeletou, Sofia; D'Aquin, Mathieu; Motta, Enrico

    The increased availability of online knowledge has led to the design of several algorithms that solve a variety of tasks by harvesting the Semantic Web, i.e., by dynamically selecting and exploring a multitude of online ontologies. Our hypothesis is that the performance of such novel algorithms implicitly provides an insight into the quality of the used ontologies and thus opens the way to a task-based evaluation of the Semantic Web. We have investigated this hypothesis by studying the lessons learnt about online ontologies when used to solve three tasks: ontology matching, folksonomy enrichment, and word sense disambiguation. Our analysis leads to a suit of conclusions about the status of the Semantic Web, which highlight a number of strengths and weaknesses of the semantic information available online and complement the findings of other analysis of the Semantic Web landscape.

  7. SWIFT: task-based hydrodynamics and gravity for cosmological simulations

    CERN Document Server

    Theuns, Tom; Schaller, Matthieu; Gonnet, Pedro

    2015-01-01

    Simulations of galaxy formation follow the gravitational and hydrodynamical interactions between gas, stars and dark matter through cosmic time. The huge dynamic range of such calculations severely limits strong scaling behaviour of the community codes in use, with load-imbalance, cache inefficiencies and poor vectorisation limiting performance. The new swift code exploits task-based parallelism designed for many-core compute nodes interacting via MPI using asynchronous communication to improve speed and scaling. A graph-based domain decomposition schedules interdependent tasks over available resources. Strong scaling tests on realistic particle distributions yield excellent parallel efficiency, and efficient cache usage provides a large speed-up compared to current codes even on a single core. SWIFT is designed to be easy to use by shielding the astronomer from computational details such as the construction of the tasks or MPI communication. The techniques and algorithms used in SWIFT may benefit other compu...

  8. Study on Real-time Task Scheduling Policy for Automated Testing of Spacecraft

    Directory of Open Access Journals (Sweden)

    Li Guoxin

    2013-05-01

    Full Text Available Spacecraft testing is an important phase of developing a spacecraft. As the test task requests in spacecraft testing have dynamic, real-time and resource constraints characteristics, it need further research on requests scheduling policy. Based on the EDF scheduling model, this study apprehends the dynamic, real timing and communicating resource limitation in automated testing of application-level device gateway in spacecraft subsystem in its design of a multiple-factor based PRI ascertain method and put forward a scheduling policy of multithreading under resource limitation. Test results show that this policy better assures scheduling effect with effectivescheduling of each parallel testing task under different task densities.

  9. Task duration in contextual interference.

    Science.gov (United States)

    Smith, Peter J K

    2002-12-01

    Duration of practice trial on a pursuit rotor task in contextual interference was investigated. Participants practiced at each of 4 angular velocities, with 24 participants completing 28 trials lasting 20 sec., and 24 participants completing 112 trials of 5 sec. Half of the participants in each trial-duration condition practiced in a blocked format and half practiced in a random format. After random practice posttest performance was better than blocked practice when practice-trial duration was 20 sec., but worse when practice-trial duration was 5 sec. This result is not consistent with theoretical explanations of the contextual interference effect and is discussed with reference to the task characteristics and demands of the pursuit rotor. PMID:12578255

  10. Task Specialization, Immigration, and Wages

    OpenAIRE

    Peri, Giovanni; Sparber, Chad

    2008-01-01

    Many workers with low levels of educational attainment immigrated to the United States in recent decades. Large inflows of less-educated immigrants would reduce wages paid to comparably-educated native-born workers if the two groups are perfectly substitutable in production. In a simple model exploiting comparative advantage, however, we show that if less-educated foreign and native-born workers specialize in performing different tasks, immigration will cause natives to reallocate their...

  11. Fuel oil quality task force

    Energy Technology Data Exchange (ETDEWEB)

    Laisy, J.; Turk, V. [R.W. Beckett Corp., Elyria, OH (United States)

    1997-09-01

    In April, 1996, the R.W. Beckett Corporation became aware of a series of apparently unrelated symptoms that made the leadership of the company concerned that there could be a fuel oil quality problem. A task force of company employees and industry consultants was convened to address the topic of current No. 2 heating oil quality and its effect on burner performance. The task force studied changes in fuel oil specifications and trends in properties that have occurred over the past few years. Experiments were performed at Beckett and Brookhaven National Laboratory to understand the effect of changes in some fuel oil properties. Studies by other groups were reviewed, and field installations were inspected to gain information about the performance of fuel oil that is currently being used in the U.S. and Canada. There was a special concern about the use of red dye in heating oils and the impact of sulfur levels due to the October, 1993 requirement of low sulfur (<0.05%) for on-highway diesel fuel. The results of the task force`s efforts were published in July, 1996. The primary conclusion of the task force was that there is not a crisis or widespread general problem with fuel oil quality. Localized problems that were seen may have been related to refinery practices and/or non-traditional fuel sources. System cleanliness is very important and the cause of many oil burner system problems. Finally, heating oil quality should get ongoing careful attention by Beckett engineering personnel and heating oil industry groups.

  12. Multi-Task Collaboration CPS Modeling Based on Immune Feedback

    Directory of Open Access Journals (Sweden)

    Haiying Li

    2013-09-01

    Full Text Available In this paper, a dynamic multi-task collaboration CPS control model based on the self-adaptive immune feedback is proposed and implemented in the smart home environment. First, the internal relations between CPS and the biological immune system are explored via their basic theories. Second, CPS control mechanism is elaborated through the analysis of CPS control structure. Finally, a comprehensive strategy for support is introduced into multi-task collaboration to improve the dynamic cognitive ability. At the same time, the performance of parameters is correspondingly increased by the operator of the antibody concentration and the selective pressure. Furthermore, the model has been put into service in the smart home laboratory. The experimental results show that this model can integrate user’s needs into the environment for properly regulating the home environment.

  13. 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 measures…

  14. Task appraisals, emotions, and performance goal orientation.

    Science.gov (United States)

    Fisher, Cynthia D; Minbashian, Amirali; Beckmann, Nadin; Wood, Robert E

    2013-03-01

    We predict real-time fluctuations in employees' positive and negative emotions from concurrent appraisals of the immediate task situation and individual differences in performance goal orientation. Task confidence, task importance, positive emotions, and negative emotions were assessed 5 times per day for 3 weeks in an experience sampling study of 135 managers. At the within-person level, appraisals of task confidence, task importance, and their interaction predicted momentary positive and negative emotions as hypothesized. Dispositional performance goal orientation was expected to moderate emotional reactivity to appraisals of task confidence and task importance. The hypothesized relationships were significant in the case of appraisals of task importance. Those high on performance goal orientation reacted to appraisals of task importance with stronger negative and weaker positive emotions than those low on performance goal orientation. PMID:23276116

  15. Software-based Approximate Computation Of Signal Processing Tasks

    OpenAIRE

    Anastasia, D.

    2012-01-01

    This thesis introduces a new dimension in performance scaling of signal processing systems by proposing software frameworks that achieve increased processing throughput when producing approximate results. The first contribution of this work is a new theory for accelerated computation of multimedia processing based on the concept of tight packing (Chapter 2). Usage of this theory accelerates small-dynamic-range linear signal processing tasks (such as convolution and transform decomposition) th...

  16. 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.

  17. Self-Paced Multi-Task Learning

    OpenAIRE

    Li, Changsheng; Wei, Fan; Yan, Junchi; Dong, Weishan; Liu, Qingshan; Zha, Hongyuan

    2016-01-01

    In this paper, we propose a novel multi-task learning (MTL) framework, called Self-Paced Multi-Task Learning (SPMTL). Different from previous works treating all tasks and instances equally when training, SPMTL attempts to jointly learn the tasks by taking into consideration the complexities of both tasks and instances. This is inspired by the cognitive process of human brain that often learns from the easy to the hard. We construct a compact SPMTL formulation by proposing a new task-oriented ...

  18. [Plasma properties research: Task 3

    International Nuclear Information System (INIS)

    The principal research activities of the Magneto-Fluid Dynamics Division relate to magnetic fusion plasma physics. In addition, there is a modest amount of work in closely related areas, including space plasma physics, fluid dynamics, and dynamical systems. Members of the Magneto-Fluid Dynamics Division maintain close contacts with fusion researchers in the US and abroad. Some of the work of the Division is clearly directed towards ITER and TPX, while other problems relate to the broader development of fusion plasma physics and to the support of other issues arising in the many experimental programs. Topics of some note in the last year that are discussed in this report are: Application of sophisticated statistical techniques to tokamak data reduction, including time series analysis of TFTR fluctuation data and spline analysis of profile data. Continuing development of edge plasma and divertor modelling, including initial ergodic divertor studies. Analysis of energetic fusion products losses from TFTR plasmas. Examination of anomalous transport in dynamical systems induced by chaotic-like Hamiltonian motion. Numerical simulation of the development of singular MHD equilibria. Exploration of the validity of moment expansions of kinetic equations for weakly collisional systems. Studies of RF- and ripple-induced helium ash removal. Ballooning mode studies in fluids and rotating stars. Studies in dynamical systems, including explosive instabilities, development of chaos, and motion of collisionless particles in a domain with overlapping islands

  19. Static and dynamic task mapping onto network on chip multiprocessors

    Directory of Open Access Journals (Sweden)

    Freddy Bolaños-Martínez

    2014-01-01

    Full Text Available Las redes en circuito integrado (NoC representan un importante paradigma de uso creciente para los sistemas multiprocesador en circuito integrado (MPSoC, debido a su flexibilidad y escalabilidad. Las estrategias de tolerancia a fallos han venido adquiriendo importancia, a medida que los procesos de manufactura incursionan en dimensiones por debajo del micrómetro y la complejidad de los diseños aumenta. Este artículo describe un algoritmo de aprendizaje incremental basado en población (PBIL, orientado a optimizar el proceso de mapeo en tiempo de diseño, así como a encontrar soluciones de mapeo óptimas en tiempo de ejecución, para hacer frente a fallos de único nodo en la red. En ambos casos, los objetivos de optimización corresponden al tiempo de ejecución de las aplicaciones y al ancho de banda pico que aparece en la red. Las simulaciones se basaron en un algoritmo de ruteo XY determinístico, operando sobre una topología de malla 2D para la NoC. Los resultados obtenidos son prometedores. El algoritmo propuesto exhibe un desempeño superior a otras técnicas reportadas cuando el tamaño del problema aumenta.

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

    Directory of Open Access Journals (Sweden)

    Emma Salo

    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.

  1. Impedance learning for robotic contact tasks using natural actor-critic algorithm.

    Science.gov (United States)

    Kim, Byungchan; Park, Jooyoung; Park, Shinsuk; Kang, Sungchul

    2010-04-01

    Compared with their robotic counterparts, humans excel at various tasks by using their ability to adaptively modulate arm impedance parameters. This ability allows us to successfully perform contact tasks even in uncertain environments. This paper considers a learning strategy of motor skill for robotic contact tasks based on a human motor control theory and machine learning schemes. Our robot learning method employs impedance control based on the equilibrium point control theory and reinforcement learning to determine the impedance parameters for contact tasks. A recursive least-square filter-based episodic natural actor-critic algorithm is used to find the optimal impedance parameters. The effectiveness of the proposed method was tested through dynamic simulations of various contact tasks. The simulation results demonstrated that the proposed method optimizes the performance of the contact tasks in uncertain conditions of the environment. PMID:19696001

  2. 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…

  3. Task descriptions versus use cases

    DEFF Research Database (Denmark)

    Lauesen, Søren; Kuhail, Mohammad Amin

    2011-01-01

    Use cases are widely used as a substantial part of requirements, also when little programming is expected (COTS-based systems, Commercial-Off-The-Shelf). Are use cases effective as requirements? To answer this question, we invited professionals and researchers to specify requirements for the same...... project: Acquire a new system to support a hotline. Among the 15 replies, eight used traditional use cases that specified a dialog between user and system. Seven used a related technique, task description, which specified the customer’s needs without specifying a dialog. It also allowed the analyst to...

  4. Reactor safety - an international task

    International Nuclear Information System (INIS)

    The dimensions and the significance of the task of ensuring reactor safety can be defined on the basis of experiences gained from Harrisburg and Chernobyl. The countries that use nuclear energy are tied together to a community by virtue of the risk they share. Therefore the GRS is working in close cooperation with the EC, OECD, IAEO and COMECON. This results in safety examinations of the Greifswald reactor, safety analyses of nuclear reactors in Germany, France and the USA and also considerations on the safety demands to be placed on new reactor concepts. (DG)

  5. TASKS OF THE "INTENSIVE READING"

    Institute of Scientific and Technical Information of China (English)

    伍向梅

    1984-01-01

    @@ To Chinese students who are learning English as a foreign language, the "intensive reading" course is of great practical value,especially in the intermediate stage,i.e.senior-middle school or the second or third year in college. "Intensive reading"implies the recognition of the configuration, pronunciation, grammatical inflexion and structure of words, sentences, paragraphs, and the whole text. It strength ens listening and speaking, affords language, content, and models for writing.It helps the student lay a solid foundation of the language. Thus, the tasks assigned to the "intensive reading" are worth studying.

  6. Computability and dynamical systems

    OpenAIRE

    Buescu, Jorge; Graça, Daniel; Zhong, Ning

    2011-01-01

    In this paper we explore results that establish a link between dynamical systems and computability theory (not numerical analysis). In the last few decades, computers have increasingly been used as simulation tools for gaining insight into dynamical behavior. However, due to the presence of errors inherent in such numerical simulations, with few exceptions, computers have not been used for the nobler task of proving mathematical results. Nevertheless, there have been some recen...

  7. EFFORTS Sub-task report on task 4.2: Cold forming

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Christensen, Thomas Vennick; Bay, Niels

    1999-01-01

    Task 4.2 is a sub-task of task 4: Physical modelling validation. In sub-task 4.2 experimental analysis of cold forming as regards form filling, interface stresses and forces and moments using sof model materials have been carried out.......Task 4.2 is a sub-task of task 4: Physical modelling validation. In sub-task 4.2 experimental analysis of cold forming as regards form filling, interface stresses and forces and moments using sof model materials have been carried out....

  8. U.S. Preventive Services Task Force

    Science.gov (United States)

    ... Public Comment In an effort to make the U.S. Preventive Services Task Force (USPSTF) recommendations clearer and ... Current as of: May 2016 Internet Citation: Home . U.S. Preventive Services Task Force. June 2016. http://www. ...

  9. Planning in Markov Stochastic Task Domains

    Directory of Open Access Journals (Sweden)

    Yong Lin

    2010-10-01

    Full Text Available In decision theoretic planning, a challenge for Markov decision processes (MDPs and partially observable Markov decision processes (POMDPs is, many problem domains contain big state spaces and complex tasks, which will result in poor solution performance. We develop a task analysis and modeling (TAM approach, in which the (POMDP model is separated into a task view and an action view. In the task view, TAM models the problem domain using a task equivalence model, with task-dependent abstract states and observations. We provide a learning algorithm to obtain the parameter values of task equivalence models. We present three typical examples to explain the TAM approach. Experimental results indicate our approach can greatly improve the computational capacity of task planning in Markov stochastic domains.

  10. Multi-task Sequence to Sequence Learning

    OpenAIRE

    Luong, Minh-Thang; Le, Quoc V.; Sutskever, Ilya; Vinyals, Oriol; Kaiser, Lukasz

    2015-01-01

    Sequence to sequence learning has recently emerged as a new paradigm in supervised learning. To date, most of its applications focused on only one task and not much work explored this framework for multiple tasks. This paper examines three multi-task learning (MTL) settings for sequence to sequence models: (a) the oneto-many setting - where the encoder is shared between several tasks such as machine translation and syntactic parsing, (b) the many-to-one setting - useful when only the decoder ...

  11. An overview of task order 10

    Energy Technology Data Exchange (ETDEWEB)

    Rousculp, Christopher L [Los Alamos National Laboratory

    2011-01-12

    Task Order 10 formalizes a collaboration in high explosive pulsed power (HEPP) experiments between LANL and VNIIEF. The focus is the VNIIEF disk explosive magnetic generator (DEMG) technology. The task order outlines a sequence of tasks and deliverables culminating in an experiment which takes place in the US utilizing US explosives and a Russian DEMG. This talk summarizes task order 10. It gives a brief history and present status in terms of the proposed high pressure EOS experiment (ALT-3).

  12. Task Complexity and Second Language Narrative Discourse.

    Science.gov (United States)

    Robinson, Peter

    1995-01-01

    Examines differences in oral narrative discourse of adult second-language learners of English on narrative tasks simulating the ability to describe events in the Here-and-Now versus the There-and-Then. Results indicate that complex tasks elicit less fluent, but more accurate and complex narration than do simpler tasks. (90 references) (Author/CK)

  13. Task Manager for the Motorola 6800

    International Nuclear Information System (INIS)

    A nucleus of multi-tasking operating systems has been implemented on a Motorola 6800 microprocessor. This control structure, called a Task Manager, is appropriate for those real-time systems which are required to handle several different asynchronous events. The general concept of a Task Manager is described. A specific implementation for a Motorola 6800 microprocessor is given and its usage defined

  14. Working Memory Costs of Task Switching

    Science.gov (United States)

    Liefooghe, Baptist; Barrouillet, Pierre; Vandierendonck, Andre; Camos, Valerie

    2008-01-01

    Although many accounts of task switching emphasize the importance of working memory as a substantial source of the switch cost, there is a lack of evidence demonstrating that task switching actually places additional demands on working memory. The present study addressed this issue by implementing task switching in continuous complex span tasks…

  15. Human Performance on the Temporal Bisection Task

    Science.gov (United States)

    Kopec, Charles D.; Brody, Carlos D.

    2010-01-01

    The perception and processing of temporal information are tasks the brain must continuously perform. These include measuring the duration of stimuli, storing duration information in memory, recalling such memories, and comparing two durations. How the brain accomplishes these tasks, however, is still open for debate. The temporal bisection task,…

  16. Machine learning analysis of binaural rowing sounds

    DEFF Research Database (Denmark)

    Johard, Leonard; Ruffaldi, Emanuele; Hoffmann, Pablo F.;

    2011-01-01

    Techniques for machine hearing are increasing their potentiality due to new application domains. In this work we are addressing the analysis of rowing sounds in natural context for the purpose of supporting a training system based on virtual environments. This paper presents the acquisition metho...... methodology and the evaluation of different machine learning techniques for classifying rowing-sound data. We see that a combination of principal component analysis and shallow networks perform equally well as deep architectures, while being much faster to train....

  17. Machine Learning Analysis of Binaural Rowing Sounds

    OpenAIRE

    Filippeschi Alessandro; Hoffmann Pablo; Ruffaldi Emanuele; Johard Leonard

    2011-01-01

    Techniques for machine hearing are increasing their potentiality due to new application domains. In this work we are addressing the analysis of rowing sounds in natural context for the purpose of supporting a training system based on virtual environments. This paper presents the acquisition methodology and the evaluation of different machine learning techniques for classifying rowing-sound data. We see that a combination of principal component analysis and shallow networks perform equally wel...

  18. Machine Learning Analysis of Binaural Rowing Sounds

    Directory of Open Access Journals (Sweden)

    Filippeschi Alessandro

    2011-12-01

    Full Text Available Techniques for machine hearing are increasing their potentiality due to new application domains. In this work we are addressing the analysis of rowing sounds in natural context for the purpose of supporting a training system based on virtual environments. This paper presents the acquisition methodology and the evaluation of different machine learning techniques for classifying rowing-sound data. We see that a combination of principal component analysis and shallow networks perform equally well as deep architectures, while being much faster to train.

  19. Binaural processing by the gecko auditory periphery

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob; Tang, Ye Zhong; Carr, Catherine E

    2011-01-01

    Tokay gecko with neurophysiological recordings from the auditory nerve. Laser vibrometry shows that their ear is a two-input system with approximately unity interaural transmission gain at the peak frequency (around 1.6 kHz). Median interaural delays are 260 μs, almost three times larger than predicted...... from gecko head size, suggesting interaural transmission may be boosted by resonances in the large, open mouth cavity (Vossen et al., 2010). Auditory nerve recordings are sensitive to both interaural time differences (ITD) and interaural level differences (ILD), reflecting the acoustical interactions...

  20. Robust visual tracking via structured multi-task sparse learning

    KAUST Repository

    Zhang, Tianzhu

    2012-11-09

    In this paper, we formulate object tracking in a particle filter framework as a structured multi-task sparse learning problem, which we denote as Structured Multi-Task Tracking (S-MTT). Since we model particles as linear combinations of dictionary templates that are updated dynamically, learning the representation of each particle is considered a single task in Multi-Task Tracking (MTT). By employing popular sparsity-inducing lp,q mixed norms (specifically p∈2,∞ and q=1), we regularize the representation problem to enforce joint sparsity and learn the particle representations together. As compared to previous methods that handle particles independently, our results demonstrate that mining the interdependencies between particles improves tracking performance and overall computational complexity. Interestingly, we show that the popular L1 tracker (Mei and Ling, IEEE Trans Pattern Anal Mach Intel 33(11):2259-2272, 2011) is a special case of our MTT formulation (denoted as the L11 tracker) when p=q=1. Under the MTT framework, some of the tasks (particle representations) are often more closely related and more likely to share common relevant covariates than other tasks. Therefore, we extend the MTT framework to take into account pairwise structural correlations between particles (e.g. spatial smoothness of representation) and denote the novel framework as S-MTT. The problem of learning the regularized sparse representation in MTT and S-MTT can be solved efficiently using an Accelerated Proximal Gradient (APG) method that yields a sequence of closed form updates. As such, S-MTT and MTT are computationally attractive. We test our proposed approach on challenging sequences involving heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that S-MTT is much better than MTT, and both methods consistently outperform state-of-the-art trackers. © 2012 Springer Science+Business Media New York.

  1. Assessing Cognitive Load on Web Search Tasks

    CERN Document Server

    Gwizdka, Jacek

    2010-01-01

    Assessing cognitive load on web search is useful for characterizing search system features and search tasks with respect to their demands on the searcher's mental effort. It is also helpful for examining how individual differences among searchers (e.g. cognitive abilities) affect the search process. We examined cognitive load from the perspective of primary and secondary task performance. A controlled web search study was conducted with 48 participants. The primary task performance components were found to be significantly related to both the objective and the subjective task difficulty. However, the relationship between objective and subjective task difficulty and the secondary task performance measures was weaker than expected. The results indicate that the dual-task approach needs to be used with caution.

  2. Collaborative construction using chat in different tasks

    Directory of Open Access Journals (Sweden)

    Néstor Roselli

    2011-06-01

    Full Text Available The objective of this research was to characterize the chat collaborative interaction of two partners in six kinds of cognitive tasks. The central hypothesis was that the task nature determines a particular kind of collaborative interaction. The six tasks tested were: to solve a logical problem, to compose a story, to read a data table, to rank opinions, to bring a scientific explanation of a domestic situation, to interpret the signification of a literature text. The 11 dyads of the sample were formed by university students. Results show significant differences between the tasks concerning the sociocognitive interaction, specially the logical-intelligent tasks related the open-interpretative tasks. Finally, there is a great difference between tasks in the personal evaluation of the difficulty and interest of each one.

  3. Garbage Collection Scheduling of Aperiodic Tasks

    Institute of Scientific and Technical Information of China (English)

    Ning Zhang; Guang-Ze Xiong

    2009-01-01

    In the previous work of garbage collection (GC) models, scheduling analysis was given based on an assumption that there were no aperiodic mutator tasks. However, it is not true in practical real-time systems. The GC algorithm which can schedule aperiodic tasks is proposed, and the variance of live memory is analyzed. In this algorithm, active tasks are deferred to be processed by GC until the states of tasks become inactive, and the saved sporadic server time can be used to schedule aperiodic tasks. Scheduling the sample task sets demonstrates that this algorithm in this paper can schedule aperiodic tasks and decrease GC work. Thus, the GC algorithm proposed is more flexible and portable.

  4. 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,…

  5. 78 FR 27969 - Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2013-05-13

    ... Program Office, Office of Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control... Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health... Prevention (CDC) announces the next meeting of the Community Preventive Services Task Force (Task Force)....

  6. 77 FR 56845 - Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2012-09-14

    ... and Analysis Program Office, Office of Surveillance, Epidemiology, and Laboratory Services, Centers... Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health... Prevention (CDC) announces the next meeting of the Community Preventive Services Task Force (Task Force)....

  7. 78 FR 2996 - Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2013-01-15

    ... and Analysis Program Office, Office of Surveillance, Epidemiology, and Laboratory Services, Centers... Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health... Prevention (CDC) announces the next meeting of the Community Preventive Services Task Force (Task Force)....

  8. 78 FR 63208 - UPDATE-Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2013-10-23

    ... Epidemiology, Analysis, and Library Services; Center for Surveillance, Epidemiology and Laboratory Services... Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of... Force (Task Force). The in-person Task Force meeting is being replaced by an abbreviated conference...

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

    Science.gov (United States)

    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…

  10. 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.…

  11. Core Task and Organizational Reality

    DEFF Research Database (Denmark)

    Vikkelsø, Signe

    2015-01-01

    Reflecting a wider trend in the social sciences, the field of organization studies has adopted an increasingly general and metaphysical vocabulary to guide and frame its analyses of life and dynamics in organizations. Where classic organizational analyses would describe organizations in terms of ...... and intervene into the practical reality of organizations. It further argues that a discipline's core objects are not anachronisms to be discarded with, but crucial for specifying reality in ways that have proven practically relevant and still are....

  12. 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

  13. Assessing Task Migration Impact on Embedded Soft Real-Time Streaming Multimedia Applications

    Directory of Open Access Journals (Sweden)

    Alimonda Andrea

    2008-01-01

    Full Text Available Abstract Multiprocessor systems on chips (MPSoCs are envisioned as the future of embedded platforms such as game-engines, smart-phones and palmtop computers. One of the main challenge preventing the widespread diffusion of these systems is the efficient mapping of multitask multimedia applications on processing elements. Dynamic solutions based on task migration has been recently explored to perform run-time reallocation of task to maximize performance and optimize energy consumption. Even if task migration can provide high flexibility, its overhead must be carefully evaluated when applied to soft real-time applications. In fact, these applications impose deadlines that may be missed during the migration process. In this paper we first present a middleware infrastructure supporting dynamic task allocation for NUMA architectures. Then we perform an extensive characterization of its impact on multimedia soft real-time applications using a software FM Radio benchmark.

  14. A Proof of Concept for Optimizing Task Parallelism by Locality Queues

    CERN Document Server

    Wittmann, Markus

    2009-01-01

    Task parallelism as employed by the OpenMP task construct, although ideal for tackling irregular problems or typical producer/consumer schemes, bears some potential for performance bottlenecks if locality of data access is important, which is typically the case for memory-bound code on ccNUMA systems. We present a programming technique which ameliorates adverse effects of dynamic task distribution by sorting tasks into locality queues, each of which is preferably processed by threads that belong to the same locality domain. Dynamic scheduling is fully preserved inside each domain, and is preferred over possible load imbalance even if non-local access is required. The effectiveness of the approach is demonstrated using a blocked six-point stencil solver as a toy model.

  15. Task-and-role-based access-control model for computational grid

    Institute of Scientific and Technical Information of China (English)

    LONG Tao; HONG Fan; WU Chi; SUN Ling-li

    2007-01-01

    Access control in a grid environment is a challenging issue because the heterogeneous nature and independent administration of geographically dispersed resources in grid require access control to use fine-grained policies. We established a task-and-role-based access-control model for computational grid (CG-TRBAC model), integrating the concepts of role-based access control (RBAC) and task-based access control (TBAC). In this model, condition restrictions are defined and concepts specifically tailored to Workflow Management System are simplified or omitted so that role assignment and security administration fit computational grid better than traditional models; permissions are mutable with the task status and system variables, and can be dynamically controlled. The CG-TRBAC model is proved flexible and extendible. It can implement different control policies. It embodies the security principle of least privilege and executes active dynamic authorization. A task attribute can be extended to satisfy different requirements in a real grid system.

  16. Assessing Task Migration Impact on Embedded Soft Real-Time Streaming Multimedia Applications

    Directory of Open Access Journals (Sweden)

    Andrea Acquaviva

    2008-01-01

    Full Text Available Multiprocessor systems on chips (MPSoCs are envisioned as the future of embedded platforms such as game-engines, smart-phones and palmtop computers. One of the main challenge preventing the widespread diffusion of these systems is the efficient mapping of multitask multimedia applications on processing elements. Dynamic solutions based on task migration has been recently explored to perform run-time reallocation of task to maximize performance and optimize energy consumption. Even if task migration can provide high flexibility, its overhead must be carefully evaluated when applied to soft real-time applications. In fact, these applications impose deadlines that may be missed during the migration process. In this paper we first present a middleware infrastructure supporting dynamic task allocation for NUMA architectures. Then we perform an extensive characterization of its impact on multimedia soft real-time applications using a software FM Radio benchmark.

  17. A Spatial Queuing-Based Algorithm for Multi-Robot Task Allocation

    Directory of Open Access Journals (Sweden)

    William Lenagh

    2015-08-01

    Full Text Available Multi-robot task allocation (MRTA is an important area of research in autonomous multi-robot systems. The main problem in MRTA is to allocate a set of tasks to a set of robots so that the tasks can be completed by the robots while ensuring that a certain metric, such as the time required to complete all tasks, or the distance traveled, or the energy expended by the robots is reduced. We consider a scenario where tasks can appear dynamically and a task needs to be performed by multiple robots to be completed. We propose a new algorithm called SQ-MRTA (Spatial Queueing-MRTA that uses a spatial queue-based model to allocate tasks between robots in a distributed manner. We have implemented the SQ-MRTA algorithm on accurately simulated models of Corobot robots within the Webots simulator for different numbers of robots and tasks and compared its performance with other state-of-the-art MRTA algorithms. Our results show that the SQ-MRTA algorithm is able to scale up with the number of tasks and robots in the environment, and it either outperforms or performs comparably with respect to other distributed MRTA algorithms.

  18. Dynamic reweighting of three modalities for sensor fusion.

    Science.gov (United States)

    Hwang, Sungjae; Agada, Peter; Kiemel, Tim; Jeka, John J

    2014-01-01

    We simultaneously perturbed visual, vestibular and proprioceptive modalities to understand how sensory feedback is re-weighted so that overall feedback remains suited to stabilizing upright stance. Ten healthy young subjects received an 80 Hz vibratory stimulus to their bilateral Achilles tendons (stimulus turns on-off at 0.28 Hz), a ± 1 mA binaural monopolar galvanic vestibular stimulus at 0.36 Hz, and a visual stimulus at 0.2 Hz during standing. The visual stimulus was presented at different amplitudes (0.2, 0.8 deg rotation about ankle axis) to measure: the change in gain (weighting) to vision, an intramodal effect; and a change in gain to vibration and galvanic vestibular stimulation, both intermodal effects. The results showed a clear intramodal visual effect, indicating a de-emphasis on vision when the amplitude of visual stimulus increased. At the same time, an intermodal visual-proprioceptive reweighting effect was observed with the addition of vibration, which is thought to change proprioceptive inputs at the ankles, forcing the nervous system to rely more on vision and vestibular modalities. Similar intermodal effects for visual-vestibular reweighting were observed, suggesting that vestibular information is not a "fixed" reference, but is dynamically adjusted in the sensor fusion process. This is the first time, to our knowledge, that the interplay between the three primary modalities for postural control has been clearly delineated, illustrating a central process that fuses these modalities for accurate estimates of self-motion. PMID:24498252

  19. Dynamic reweighting of three modalities for sensor fusion.

    Directory of Open Access Journals (Sweden)

    Sungjae Hwang

    Full Text Available We simultaneously perturbed visual, vestibular and proprioceptive modalities to understand how sensory feedback is re-weighted so that overall feedback remains suited to stabilizing upright stance. Ten healthy young subjects received an 80 Hz vibratory stimulus to their bilateral Achilles tendons (stimulus turns on-off at 0.28 Hz, a ± 1 mA binaural monopolar galvanic vestibular stimulus at 0.36 Hz, and a visual stimulus at 0.2 Hz during standing. The visual stimulus was presented at different amplitudes (0.2, 0.8 deg rotation about ankle axis to measure: the change in gain (weighting to vision, an intramodal effect; and a change in gain to vibration and galvanic vestibular stimulation, both intermodal effects. The results showed a clear intramodal visual effect, indicating a de-emphasis on vision when the amplitude of visual stimulus increased. At the same time, an intermodal visual-proprioceptive reweighting effect was observed with the addition of vibration, which is thought to change proprioceptive inputs at the ankles, forcing the nervous system to rely more on vision and vestibular modalities. Similar intermodal effects for visual-vestibular reweighting were observed, suggesting that vestibular information is not a "fixed" reference, but is dynamically adjusted in the sensor fusion process. This is the first time, to our knowledge, that the interplay between the three primary modalities for postural control has been clearly delineated, illustrating a central process that fuses these modalities for accurate estimates of self-motion.

  20. The task complexity experiment 2003/2004

    International Nuclear Information System (INIS)

    The purpose of this experiment was to explore how additional tasks added to base case scenarios affected the operators' performance of the main tasks. These additional tasks were in different scenario variants intended to cause high time pressure, high information load, and high masking. The experiment was run in Halden Man-Machine Laboratory's BWR simulator. Seven crews participated, each for one week. There were three operators in each crew. Five main types of scenarios and 20 scenario variants were run. The data from the experiment were analysed by completion time for important actions and by in-depth qualitative analyses of the crews' communications. The results showed that high time pressure decreased some of the crews' performance in the scenarios. When a crew had problems in solving a task for which the time pressure was high, they had even more problems in solving other important tasks. High information load did not affect the operators' performance much and in general the crews were very good at selecting the most important tasks in the scenarios. The scenarios that included both high time pressure and high information load resulted in more reduced performance for the crews compared to the scenarios that only included high time pressure. The total amount of tasks to do and information load to attend to seemed to affect the crews' performance. To solve the scenarios with high time pressure well, it was important to have good communication and good allocation of tasks within the crew. Furthermore, the results showed that scenarios with an added complex, masked task created problems for some crews when solving a relatively simple main task. Overall, the results confirmed that complicating, but secondary tasks, that are not normally taken into account when modelling the primary tasks in a PRA scenario can adversely affect the performance of the main tasks modelled in the PRA scenario. (Author)

  1. Training recurrent neural networks with sparse, delayed rewards for flexible decision tasks

    OpenAIRE

    Miconi, Thomas

    2015-01-01

    Recurrent neural networks in the chaotic regime exhibit complex dynamics reminiscent of high-level cortical activity during behavioral tasks. However, existing training methods for such networks are either biologically implausible, or require a real-time continuous error signal to guide the learning process. This is in contrast with most behavioral tasks, which only provide time-sparse, delayed rewards. Here we show that a biologically plausible reward-modulated Hebbian learning algorithm, pr...

  2. Stability and task complexity: a neural network model of genetic assimilation

    OpenAIRE

    Watson, J.; Geard, N; Wiles, J

    2002-01-01

    Since Hinton and Nowlan introduced the Baldwin effect to the evolutionary computation community, agent-based studies of genetic assimilation have uncovered many details of the dynamic processes involved. In a previous paper, we demonstrated genetic assimilation with a simple food/toxin discrimination task using neural network agents that could evolve their learning rate. The study reported in this paper investigated the genetic assimilation of more complex learning tasks. Kauffman's NK landsc...

  3. Interaction between articulatory gestures and inner speech in a counting task

    OpenAIRE

    Hadian Cefidekhanie, Ali; Savariaux, Christophe; Sato, Marc; Schwartz, Jean-Luc

    2014-01-01

    Interaction between covert and overt orofacial gestures has been poorly studied apart from old and rather qualitative experiments. The question deserves special interest in the context of the debate between auditory and motor theories of speech perception, where dual tasks may be of great interest. It is shown here that dynamic mandible and lips movement produced by a participant result in strong and stable perturbations to an inner speech counting task that has to be realized at the same tim...

  4. A Research of Task-based Language Teaching Applied to the College Oral English Teaching

    Institute of Scientific and Technical Information of China (English)

    王景琦; 祝菁

    2016-01-01

    Task-based Language Teaching has been greatly applied to college English teaching after the traditional “PPP”teaching approach. The key links in TBLT are assignment, development and inspection of tasks. With the main method, interactive communication,“students-centered ” is stressed, and students' subjective dynamics is fully exerted. Class time can be effectively used and students' communicative ability is cultivated with the improvement of oral expression ability.

  5. Do Cost Functions for Tracking Error Generalize across Tasks with Different Noise Levels?

    OpenAIRE

    Sensinger, Jonathon; Aleman-Zapata, Adrian; Englehart, Kevin

    2015-01-01

    Control of human-machine interfaces are well modeled by computational control models, which take into account the behavioral decisions people make in estimating task dynamics and state for a given control law. This control law is optimized according to a cost function, which for the sake of mathematical tractability is typically represented as a series of quadratic terms. Recent studies have found that people actually use cost functions for reaching tasks that are slightly different than a qu...

  6. Self-organized criticality and learning a new coordination task.

    Science.gov (United States)

    Liu, Yeou-Teh; Luo, Zong-Yi; Mayer-Kress, Gottfried; Newell, Karl M

    2012-02-01

    The purpose of this study was to investigate the hypothesis that a self-organized criticality (SOC) practice condition would have a higher improvement rate in performance outcome than a typical progressive difficulty of practice regimen. The roller ball task was used where participants undergo a phase transition from failure to successful performance after sufficient practice. The findings from two experiments showed that the SOC condition had the fastest rate of improvement and the highest performance success level. The success probability in the SOC practice regime was close to the theoretically predicted value of 50%. It appears that the SOC practice condition - by scaling task difficulty to skill level in a self-controlled adaptive strategy - facilitates the learning of new movement coordination pattern by keeping the participant close to the parameter region of the transition of the movement dynamics. PMID:21831466

  7. 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.

  8. Unnecessary work tasks and mental health

    DEFF Research Database (Denmark)

    Madsen, Ida E H; Tripathi, Manisha; Borritz, Marianne;

    2014-01-01

    is modified by sex, age, occupational position, and baseline mental health status. METHODS: The data were obtained from self-administered questionnaires from 1351 Danish human service workers in three waves of data-collection during 1999-2005. We measured unnecessary work tasks by a single item, and assessed......OBJECTIVES: According to the "stress-as-offense-to-self" perspective, work tasks that are considered unnecessary or unreasonable - so-called "illegitimate work tasks" - are likely to elicit stress-reactions. Previous studies, mostly cross-sectional, have shown that illegitimate tasks are associated...... with increased self-reported stress, cortisol, and counterproductive work behavior. In this article, we examine the prospective association between unnecessary work tasks, one type of illegitimate work tasks, and mental health among Danish human service workers. Further, we explore whether this association...

  9. An informal analysis of flight control tasks

    Science.gov (United States)

    Andersen, George J.

    1991-01-01

    Issues important in rotorcraft flight control are discussed. A perceptual description is suggested of what is believed to be the major issues in flight control. When the task is considered of a pilot controlling a helicopter in flight, the task is decomposed in several subtasks. These subtasks include: (1) the control of altitude, (2) the control of speed, (3) the control of heading, (4) the control of orientation, (5) the control of flight over obstacles, and (6) the control of flight to specified positions in the world. The first four subtasks can be considered to be primary control tasks as they are not dependent on any other subtasks. However, the latter two subtasks can be considered hierarchical tasks as they are dependent on other subtasks. For example, the task of flight control over obstacles can be decomposed as a task requiring the control of speed, altitude, and heading. Thus, incorrect control of altitude should result in poor control of flight over an obstacle.

  10. Overview of job and task analysis

    International Nuclear Information System (INIS)

    During the past few years the nuclear industry has become concerned with predicting human performance in nuclear power plants. One of the best means available at the present time to make sure that training, procedures, job performance aids and plant hardware match the capabilities and limitations of personnel is by performing a detailed analysis of the tasks required in each job position. The approved method for this type of analysis is referred to as job or task analysis. Job analysis is a broader type of analysis and is usually thought of in terms of establishing overall performance objectives, and in establishing a basis for position descriptions. Task analysis focuses on the building blocks of task performance, task elements, and places them within the context of specific performance requirements including time to perform, feedback required, special tools used, and required systems knowledge. The use of task analysis in the nuclear industry has included training validation, preliminary risk screening, and procedures development

  11. Task-Driven Activity Reduces the Cortical Activity Space of the Brain: Experiment and Whole-Brain Modeling.

    OpenAIRE

    Adrián Ponce-Alvarez; He, Biyu J.; Patric Hagmann; Gustavo Deco

    2015-01-01

    How a stimulus or a task alters the spontaneous dynamics of the brain remains a fundamental open question in neuroscience. One of the most robust hallmarks of task/stimulus-driven brain dynamics is the decrease of variability with respect to the spontaneous level, an effect seen across multiple experimental conditions and in brain signals observed at different spatiotemporal scales. Recently, it was observed that the trial-to-trial variability and temporal variance of functional magnetic reso...

  12. Expressing Coarse-Grain Dependencies Among Tasks in Shared Memory Programs

    DEFF Research Database (Denmark)

    Larsen, Per; Karlsson, Sven; Madsen, Jan

    2011-01-01

    Designers of embedded systems face tight constraints on resources, response time and cost. The ability to analyze embedded systems is essential to timely delivery of new designs. Many analysis techniques model parallel programs as task graphs. Task graphs capture the worst-case execution times...... dependencies that do not occur at runtime. This lets tools compute more accurate task graphs from the annotated code. The correct use of the directives cannot be verified at compile time. Therefore, the check for correct use is done at runtime—not unlike dynamic array bounds checking in many languages...

  13. CDTOM: A Context-driven Task-oriented Middleware for Pervasive Homecare Environment

    Directory of Open Access Journals (Sweden)

    Hongbo Ni

    2011-02-01

    Full Text Available With the growing number of the elderly, we see a greater demand for home care, and the vision of pervasive computing is also floating into the domain of the household that aims to build a smart homewhich can assist inhabitants (users to live more conveniently and harmoniously. Such health-care pervasive applications in smart home should focus on the inhabitant’s goal or task in diverse situations,rather than the various complex devices and services. The core challenge for homecare design is to perceive the environment and assess occurring situations, thus allowing systems to behave intelligently according to the user’s intent. Due to the dynamic and heterogeneous nature of pervasive computing environment, it is difficult for an average user to obtain right information and service and in right place at right time. This paper proposes a context-driven task-oriented middleware (CDTOM to meet the challenge. The most important component is its task model that provides an adequate high-level description of user-oriented tasks and their related contexts. Leveraging the model multiple entities can easilyexchange, share and reuse their knowledge. Based on the hierarchy of task ontology, a novel task recognition approach using CBR (case-based reasoning is presented and the performance of taskrecognition is evaluated by task number, context size and time costing. Moreover, a dynamic mechanism for mapping the recognized task and services is also discussed. Finally, we present the design and implementation of our task supporting system (TSS to aid an inhabitant’s tasks in light of his lifestyle and environment conditions in pervasive homecare environment, and the results of the prototype system show that our middleware approach achieves good efficiency of context management and good accuracy ofuser’s activity inference, and can improve efficiently quality of user’s life.

  14. Task repetition and second language speech processing

    OpenAIRE

    Lambert, Craig; Kormos, Judit; Minn, Danny

    2016-01-01

    This study examines the relationship between the repetition of oral monologue tasks and immediate gains in L2 fluency. It considers the effect of aural-oral task repetition on speech rate, frequency of clause-final and mid-clause filled pauses, and overt self-repairs across different task types and proficiency levels and relates these findings to specific stages of L2 speech production (conceptualization, formulation and monitoring). Thirty-two Japanese learners of English sampled at three le...

  15. Simultaneous Acquisition of Task and Feedback Models

    OpenAIRE

    Lopes, Manuel; Cederborg, Thomas; Oudeyer, Pierre-Yves

    2011-01-01

    International audience We present a system to learn task representations from ambiguous feedback. We consider an inverse reinforcement learner that receives feedback from a teacher with an unknown and noisy protocol. The system needs to estimate simultaneously what the task is (i.e. how to find a compact representation to the task goal), and how the teacher is providing the feedback. We further explore the problem of ambiguous protocols by considering that the words used by the teacher hav...

  16. Scheduling Independent Tasks with Voltage Overscaling

    OpenAIRE

    Cavelan, Aurélien; Robert, Yves; Sun, Hongyang; Vivien, Frédéric

    2015-01-01

    In this paper, we discuss several scheduling algorithms to execute independent tasks with voltage overscaling. Given a frequency to execute the tasks, operating at a voltage below threshold leads to significant energy savings but also induces timing errors. A verification mechanism must be enforced to detect these errors. Contrarily to fail-stop or silent errors, timing errors are deterministic (but unpredictable). For each task, the general strategy is to select a voltage for execution, to c...

  17. Predictive performance models and multiple task performance

    Science.gov (United States)

    Wickens, Christopher D.; Larish, Inge; Contorer, Aaron

    1989-01-01

    Five models that predict how performance of multiple tasks will interact in complex task scenarios are discussed. The models are shown in terms of the assumptions they make about human operator divided attention. The different assumptions about attention are then empirically validated in a multitask helicopter flight simulation. It is concluded from this simulation that the most important assumption relates to the coding of demand level of different component tasks.

  18. Assessing Cognitive Load on Web Search Tasks

    OpenAIRE

    Gwizdka, Jacek

    2010-01-01

    Assessing cognitive load on web search is useful for characterizing search system features and search tasks with respect to their demands on the searcher's mental effort. It is also helpful for examining how individual differences among searchers (e.g. cognitive abilities) affect the search process. We examined cognitive load from the perspective of primary and secondary task performance. A controlled web search study was conducted with 48 participants. The primary task performance components...

  19. Common EEG features for behavioral estimation in disparate, real-world tasks.

    Science.gov (United States)

    Touryan, Jon; Lance, Brent J; Kerick, Scott E; Ries, Anthony J; McDowell, Kaleb

    2016-02-01

    In this study we explored the potential for capturing the behavioral dynamics observed in real-world tasks from concurrent measures of EEG. In doing so, we sought to develop models of behavior that would enable the identification of common cross-participant and cross-task EEG features. To accomplish this we had participants perform both simulated driving and guard duty tasks while we recorded their EEG. For each participant we developed models to estimate their behavioral performance during both tasks. Sequential forward floating selection was used to identify the montage of independent components for each model. Linear regression was then used on the combined power spectra from these independent components to generate a continuous estimate of behavior. Our results show that oscillatory processes, evidenced in EEG, can be used to successfully capture slow fluctuations in behavior in complex, multi-faceted tasks. The average correlation coefficients between the actual and estimated behavior was 0.548 ± 0.117 and 0.701 ± 0.154 for the driving and guard duty tasks respectively. Interestingly, through a simple clustering approach we were able to identify a number of common components, both neural and eye-movement related, across participants and tasks. We used these component clusters to quantify the relative influence of common versus participant-specific features in the models of behavior. These findings illustrate the potential for estimating complex behavioral dynamics from concurrent measures from EEG using a finite library of universal features. PMID:26748290

  20. Feasibility of the adaptive and automatic presentation of tasks (ADAPT system for rehabilitation of upper extremity function post-stroke

    Directory of Open Access Journals (Sweden)

    Choi Younggeun

    2011-08-01

    Full Text Available Abstract Background Current guidelines for rehabilitation of arm and hand function after stroke recommend that motor training focus on realistic tasks that require reaching and manipulation and engage the patient intensively, actively, and adaptively. Here, we investigated the feasibility of a novel robotic task-practice system, ADAPT, designed in accordance with such guidelines. At each trial, ADAPT selects a functional task according to a training schedule and with difficulty based on previous performance. Once the task is selected, the robot picks up and presents the corresponding tool, simulates the dynamics of the tasks, and the patient interacts with the tool to perform the task. Methods Five participants with chronic stroke with mild to moderate impairments (> 9 months post-stroke; Fugl-Meyer arm score 49.2 ± 5.6 practiced four functional tasks (selected out of six in a pre-test with ADAPT for about one and half hour and 144 trials in a pseudo-random schedule of 3-trial blocks per task. Results No adverse events occurred and ADAPT successfully presented the six functional tasks without human intervention for a total of 900 trials. Qualitative analysis of trajectories showed that ADAPT simulated the desired task dynamics adequately, and participants reported good, although not excellent, task fidelity. During training, the adaptive difficulty algorithm progressively increased task difficulty leading towards an optimal challenge point based on performance; difficulty was then continuously adjusted to keep performance around the challenge point. Furthermore, the time to complete all trained tasks decreased significantly from pretest to one-hour post-test. Finally, post-training questionnaires demonstrated positive patient acceptance of ADAPT. Conclusions ADAPT successfully provided adaptive progressive training for multiple functional tasks based on participant's performance. Our encouraging results establish the feasibility of ADAPT; its

  1. The core task in project management

    OpenAIRE

    Rennels, Julie Lina; Prip, Mathias Nissen; Maansen, Simon Hornung

    2016-01-01

    The main focus of this thesis is the core task concept and how it has been integrated in the public sector. The core task brings new ideas to the table in form of new management techniques and provides a different focus on values in the public sector. The key elements of the core task is trust and acknowledgement throughout the organization. In relation to this, the idea is to examine the solving of the core task, and how this affects an actual interorganizational collaboration, and what oppo...

  2. Analysis of Task-based Syllabus

    Institute of Scientific and Technical Information of China (English)

    马进胜

    2011-01-01

    Task-based language teaching is very popular in the modem English teaching.It is based on the Task-based Syllabus.Taskbased Syllabus focuses on the learners' communicative competence,which stresses learning by doing.From the theoretical assumption and definitions of the task,the paper analysizes the components of the task,then points out the merits and demerits of the syllabus.By this means the paper may give some tips to teachers and students when they use the tsk-based language teaching.

  3. Guessing versus Choosing an Upcoming Task.

    Science.gov (United States)

    Kleinsorge, Thomas; Scheil, Juliane

    2016-01-01

    We compared the effects of guessing vs. choosing an upcoming task. In a task-switching paradigm with four tasks, two groups of participants were asked to either guess or choose which task will be presented next under otherwise identical conditions. The upcoming task corresponded to participants' guesses or choices in 75 % of the trials. However, only participants in the Choosing condition were correctly informed about this, whereas participants in the Guessing condition were told that tasks were determined at random. In the Guessing condition, we replicated previous findings of a pronounced reduction of switch costs in case of incorrect guesses. This switch cost reduction was considerably less pronounced with denied choices in the Choosing condition. We suggest that in the Choosing condition, the signaling of prediction errors associated with denied choices is attenuated because a certain proportion of denied choices is consistent with the overall representation of the situation as conveyed by task instructions. In the Guessing condition, in contrast, the mismatch of guessed and actual task is resolved solely on the level of individual trials by strengthening the representation of the actual task. PMID:27047423

  4. Task oriented evaluation system for maintenance robots

    International Nuclear Information System (INIS)

    The adaptability evaluation of maintenance robots to autonomous plants has been discussed. In this paper, a new concept of autonomous plant with maintenance robots are introduced, and a framework of autonomous maintenance system is proposed. Then, task-oriented evaluation of robot arms is discussed for evaluating their adaptability to maintenance tasks, and a new criterion called operability is proposed for adaptability evaluation. The task-oriented evaluation system is implemented and applied to structural design of robot arms. Using genetic algorithm, an optimal structure adaptable to a pump disassembly task is obtained. (author)

  5. Task Release Control for Decision Making Queues

    CERN Document Server

    Srivastava, Vaibhav; Bullo, Francesco; Langbort, Cédric

    2010-01-01

    We consider the optimal duration allocation in a decision making queue. Decision making tasks arrive at a given rate to a human operator. The correctness of the decision made by human evolves as a sigmoidal function of the duration allocated to the task. Each task in the queue loses its value continuously. We elucidate on this trade-off and determine optimal policies for the human operator. We show the optimal policy requires the human to drop some tasks. We present a receding horizon optimization strategy, and compare it with the greedy policy.

  6. Task 7c: Worm tank

    International Nuclear Information System (INIS)

    Worm tank has a unique shape. In the seismic design of a worm tank, it is desirable to clear the behavior of the worm tank under the seismic loading. We assumed that there are two phenomena in the seismic behavior of the worm tank same as the behavior of the cylindrical and rectangular tanks. One is a sloshing behavior of the water and another is the dynamic response of the worm tank. In this study, we investigate the dynamic characteristics of the worm tank during the strong earthquakes. We conducted the vibration tests to clarify the seismic behaviors of the worm tanks and obtained the valuable data to verify the analytical method. It was found that the natural frequency can be calculated using the eigenvalue formula of the cylindrical and rectangular tanks. Lower modes of the worm tank are identical with that of the rectangular tank. We can estimate the surface behavior and the impact mode using the data of the rectangular tank. (author)

  7. 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…

  8. Dual-Task Processing When Task 1 Is Hard and Task 2 Is Easy: Reversed Central Processing Order?

    Science.gov (United States)

    Leonhard, Tanja; Fernandez, Susana Ruiz; Ulrich, Rolf; Miller, Jeff

    2011-01-01

    Five psychological refractory period (PRP) experiments were conducted with an especially time-consuming first task (Experiments 1, 3, and 5: mental rotation; Experiments 2 and 4: memory scanning) and with equal emphasis on the first task and on the second (left-right tone judgment). The standard design with varying stimulus onset asynchronies…

  9. Drug and alcohol task force

    Energy Technology Data Exchange (ETDEWEB)

    Gordey, T. [ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Sunstrum, M. [Enform, Calgary, AB (Canada)

    2006-07-01

    Worker absenteeism due to substance abuse costs the Alberta economy approximately $720 million a year. It is estimated that 20 per cent of all drivers in fatal crashes were using alcohol, and the use of cannabis and cocaine in Alberta has more than doubled over the last 15 years. In addition, 1 in 10 Alberta workers have reported using alcohol while at work and 4 per cent have reported using alcohol 4 hours prior to coming to work during the previous 12 months. In an effort to ensure appropriate health and safety for workers in the Canadian petroleum industry, 6 trade associations in the sector have joined together as the Enform Alcohol and Drug Initiative and are now working to develop a common approach to drug and alcohol guidelines and workplace rules. The task group will determine if existing policies and guidelines are sufficient to ensure a safe workplace and will consider standardizing the testing, application and rehabilitation of workers with respect to the use of drugs and alcohol. In the past, disciplinary actions have often been reversed because employers have not been consistent or did not follow established alcohol and drug policies or test to specific standards. Various work rules for inappropriate alcohol and drug use were reviewed, as well as education and communication strategies regarding policy content. Standards for testing criteria were discussed, as well as issues concerning duty-to-accommodate circumstances. An excerpt of concentration standards was presented. It was concluded that a matrix for companies to assess and determine safety sensitive positions is needed. refs., tabs., figs.

  10. Synchronizing Parallel Tasks Using STM

    Directory of Open Access Journals (Sweden)

    Ryan Saptarshi Ray

    2015-03-01

    Full Text Available The past few years have marked the start of a historic transition from sequential to parallel computation. The necessity to write parallel programs is increasing as systems are getting more complex while processor speed increases are slowing down. Current parallel programming uses low-level programming constructs like threads and explicit synchronization using locks to coordinate thread execution. Parallel programs written with these constructs are difficult to design, program and debug. Also locks have many drawbacks which make them a suboptimal solution. One such drawback is that locks should be only used to enclose the critical section of the parallel-processing code. If locks are used to enclose the entire code then the performance of the code drastically decreases. Software Transactional Memory (STM is a promising new approach to programming shared-memory parallel processors. It is a concurrency control mechanism that is widely considered to be easier to use by programmers than locking. It allows portions of a program to execute in isolation, without regard to other, concurrently executing tasks. A programmer can reason about the correctness of code within a transaction and need not worry about complex interactions with other, concurrently executing parts of the program. If STM is used to enclose the entire code then the performance of the code is the same as that of the code in which STM is used to enclose the critical section only and is far better than code in which locks have been used to enclose the entire code. So STM is easier to use than locks as critical section does not need to be identified in case of STM. This paper shows the concept of writing code using Software Transactional Memory (STM and the performance comparison of codes using locks with those using STM. It also shows why the use of STM in parallel-processing code is better than the use of locks.

  11. TASK 2: QUENCH ZONE SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Fusselman, Steve

    2015-09-30

    Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. A key feature of the AR gasifier design is the transition from the gasifier outlet into the quench zone, where the raw syngas is cooled to ~ 400°C by injection and vaporization of atomized water. Earlier pilot plant testing revealed a propensity for the original gasifier outlet design to accumulate slag in the outlet, leading to erratic syngas flow from the outlet. Subsequent design modifications successfully resolved this issue in the pilot plant gasifier. In order to gain greater insight into the physical phenomena occurring within this zone, AR developed a cold flow simulation apparatus with Coanda Research & Development with a high degree of similitude to hot fire conditions with the pilot scale gasifier design, and capable of accommodating a scaled-down quench zone for a demonstration-scale gasifier. The objective of this task was to validate similitude of the cold flow simulation model by comparison of pilot-scale outlet design performance, and to assess demonstration scale gasifier design feasibility from testing of a scaled-down outlet design. Test results did exhibit a strong correspondence with the two pilot scale outlet designs, indicating credible similitude for the cold flow simulation device. Testing of the scaled-down outlet revealed important considerations in the design and operation of the demonstration scale gasifier, in particular pertaining to the relative momentum between the downcoming raw syngas and the sprayed quench water and associated impacts on flow patterns within the quench zone. This report describes key findings from the test program, including assessment of pilot plant configuration simulations relative to actual

  12. Drug and alcohol task force

    International Nuclear Information System (INIS)

    Worker absenteeism due to substance abuse costs the Alberta economy approximately $720 million a year. It is estimated that 20 per cent of all drivers in fatal crashes were using alcohol, and the use of cannabis and cocaine in Alberta has more than doubled over the last 15 years. In addition, 1 in 10 Alberta workers have reported using alcohol while at work and 4 per cent have reported using alcohol 4 hours prior to coming to work during the previous 12 months. In an effort to ensure appropriate health and safety for workers in the Canadian petroleum industry, 6 trade associations in the sector have joined together as the Enform Alcohol and Drug Initiative and are now working to develop a common approach to drug and alcohol guidelines and workplace rules. The task group will determine if existing policies and guidelines are sufficient to ensure a safe workplace and will consider standardizing the testing, application and rehabilitation of workers with respect to the use of drugs and alcohol. In the past, disciplinary actions have often been reversed because employers have not been consistent or did not follow established alcohol and drug policies or test to specific standards. Various work rules for inappropriate alcohol and drug use were reviewed, as well as education and communication strategies regarding policy content. Standards for testing criteria were discussed, as well as issues concerning duty-to-accommodate circumstances. An excerpt of concentration standards was presented. It was concluded that a matrix for companies to assess and determine safety sensitive positions is needed. refs., tabs., figs

  13. Achieving Reliability in Master-worker Computing via Evolutionary Dynamics

    OpenAIRE

    Christoforou, Evgenia; Fernández Anta, Antonio; Georgiou, Chryssis; Mosteiro, Miguel A.; Sánchez, Angel

    2012-01-01

    This work considers Internet-based task computations in which a master process assigns tasks, over the Internet, to rational workers and collect their responses. The objective is for the master to obtain the correct task outcomes. For this purpose we formulate and study the dynamics of evolution of Internet-based master-worker computations through reinforcement learning.

  14. Computer support for cooperative tasks in Mission Operations Centers

    Science.gov (United States)

    Fox, Jeffrey; Moore, Mike

    1994-01-01

    Traditionally, spacecraft management has been performed by fixed teams of operators in Mission Operations Centers. The team cooperatively: (1) ensures that payload(s) on spacecraft perform their work; and (2) maintains the health and safety of the spacecraft through commanding and monitoring the spacecraft's subsystems. In the future, the task demands will increase and overload the operators. This paper describes the traditional spacecraft management environment and describes a new concept in which groupware will be used to create a Virtual Mission Operations Center. Groupware tools will be used to better utilize available resources through increased automation and dynamic sharing of personnel among missions.

  15. SOCIAL MEDIA MINING SHARED TASK WORKSHOP.

    Science.gov (United States)

    Sarker, Abeed; Nikfarjam, Azadeh; Gonzalez, Graciela

    2016-01-01

    Social media has evolved into a crucial resource for obtaining large volumes of real-time information. The promise of social media has been realized by the public health domain, and recent research has addressed some important challenges in that domain by utilizing social media data. Tasks such as monitoring flu trends, viral disease outbreaks, medication abuse, and adverse drug reactions are some examples of studies where data from social media have been exploited. The focus of this workshop is to explore solutions to three important natural language processing challenges for domain-specific social media text: (i) text classification, (ii) information extraction, and (iii) concept normalization. To explore different approaches to solving these problems on social media data, we designed a shared task which was open to participants globally. We designed three tasks using our in-house annotated Twitter data on adverse drug reactions. Task 1 involved automatic classification of adverse drug reaction assertive user posts; Task 2 focused on extracting specific adverse drug reaction mentions from user posts; and Task 3, which was slightly ill-defined due to the complex nature of the problem, involved normalizing user mentions of adverse drug reactions to standardized concept IDs. A total of 11 teams participated, and a total of 24 (18 for Task 1, and 6 for Task 2) system runs were submitted. Following the evaluation of the systems, and an assessment of their innovation/novelty, we accepted 7 descriptive manuscripts for publication--5 for Task 1 and 2 for Task 2. We provide descriptions of the tasks, data, and participating systems in this paper. PMID:26776221

  16. Different neuroplasticity for task targets and distractors.

    Directory of Open Access Journals (Sweden)

    Elsie Y Spingath

    Full Text Available Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from

  17. Evaluation of 2 cognitive abilities tests in a dual-task environment

    Science.gov (United States)

    Vidulich, M. A.; Tsang, P. S.

    1986-01-01

    Most real world operators are required to perform multiple tasks simultaneously. In some cases, such as flying a high performance aircraft or trouble shooting a failing nuclear power plant, the operator's ability to time share or process in parallel" can be driven to extremes. This has created interest in selection tests of cognitive abilities. Two tests that have been suggested are the Dichotic Listening Task and the Cognitive Failures Questionnaire. Correlations between these test results and time sharing performance were obtained and the validity of these tests were examined. The primary task was a tracking task with dynamically varying bandwidth. This was performed either alone or concurrently with either another tracking task or a spatial transformation task. The results were: (1) An unexpected negative correlation was detected between the two tests; (2) The lack of correlation between either test and task performance made the predictive utility of the tests scores appear questionable; (3) Pilots made more errors on the Dichotic Listening Task than college students.

  18. Studying different tasks of implicit learning across multiple test sessions conducted on the web

    Directory of Open Access Journals (Sweden)

    Werner eSævland

    2016-06-01

    Full Text Available Implicit learning is usually studied through individual performance on a single task, with the most common tasks being Serial Reaction Time task (SRT; Nissen and Bullemer, 1987, Dynamic System Control task (DSC; (Berry and Broadbent, 1984 and artificial Grammar Learning task (AGL; (Reber, 1967. Few attempts have been made to compare performance across different implicit learning tasks within the same experiment. The current experiment was designed study the relationship between performance on the DSC Sugar factory task (Berry and Broadbent, 1984 and the Alternating Serial Reaction Time task (ASRT; (Howard and Howard, 1997. We also addressed another limitation to traditional implicit learning experiments, namely that implicit learning is usually studied in laboratory settings over a restricted time span lasting for less than an hour (Berry and Broadbent, 1984; Nissen and Bullemer, 1987; Reber, 1967. In everyday situations, implicit learning is assumed to involve a gradual accumulation of knowledge across several learning episodes over a larger time span (Norman and Price, 2012. One way to increase the ecological validity of implicit learning experiments could be to present the learning material repeatedly across shorter experimental sessions (Howard and Howard, 1997; Cleeremans and McClelland, 1991. This can most easily be done by using a web-based setup that participants can access from home. We therefore created an online web-based system for measuring implicit learning that could be administered in either single or multiple sessions. Participants (n = 66 were assigned to either a single-session or a multi-session condition. Learning and the degree of conscious awareness of the learned regularities was compared across condition (single vs. multiple sessions and tasks (DSC vs. ASRT. Results showed that learning on the two tasks was not related. However, participants in the multiple sessions condition did show greater improvements in reaction

  19. Adaptation to (non)valent task disturbance.

    Science.gov (United States)

    Kunde, Wilfried; Augst, Susanne; Kleinsorge, Thomas

    2012-12-01

    The cognitive system adapts to disturbances caused by task-irrelevant information. For example, interference due to irrelevant spatial stimulation (e.g., the spatial Simon effect) typically diminishes right after a spatially incongruent event. These adaptation effects reflect processes that help to overcome the impact of task-irrelevant information. Interference with (or interruption of) task processing can also result from valent (i.e., positive or negative) stimuli, such as in the "affective Simon" task. In the present study, we tested whether the resolution of valence-based task disturbances generalizes to the resolution of other cognitive (spatial) types of interference, and vice versa. Experiments 1 and 2 explored the interplay of adaptation effects triggered by spatial and affective interference. Incongruent spatial information modified the spatial Simon effect but not affective interference effects, whereas incongruent affective information modified affective interference effects to some extent, but not spatial Simon effects. In Experiment 3, we investigated the interplay of adaptation effects triggered by spatial interference and by the interruption of task processing from valent information that did not overlap with the main task ("emotional Stroop" effect). Again we observed domain-specific adaptation for the spatial Simon effect but found no evidence for cross-domain modulations. We assume that the processes used to resolve task disturbance from irrelevant affective and spatial information operate in largely independent manners. PMID:22936069

  20. Optimization: Old Dogs and New Tasks

    Science.gov (United States)

    Kaplan, Jennifer J.; Otten, Samuel

    2012-01-01

    This article introduces an optimization task with a ready-made motivating question that may be paraphrased as follows: "Are you smarter than a Welsh corgi?" The authors present the task along with descriptions of the ways in which two groups of students approached it. These group vignettes reveal as much about the nature of calculus students'…

  1. What Writing Tasks Do TESOL Professors Require?

    Science.gov (United States)

    Cho, Hyonsuk

    2014-01-01

    Previous studies about writing assignments in higher education have explained that the library research paper, report on experiment, summary, and article/book review were the most common writing assignment tasks assigned across disciplines. No previous studies have explored writing tasks in the TESOL discipline at a national level. In this study…

  2. Cross Cultural Task Cards: Social Studies.

    Science.gov (United States)

    Quinn, Jeanette; Carty, Elaine

    Twenty cross-cultural learning tasks focus on concepts developed through units on food, clothing, shelter, and natural resources. The tasks progress from simple to complex. They focus on concepts and vocabulary on culture, beginning with a discussion of housing and clothing and concluding with discussions on slavery and the Bill of Rights. Each…

  3. A Hybrid Task Scheduling Algorithm in Grid

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan-mei; CAO Huai-hu; YU Zhen-wei

    2006-01-01

    Task scheduling in Grid has been proved to be NP- complete problem. In this paper, to solve this problem, a Hybrid Task Scheduling Algorithm in Grid (HTS) has been presented, which joint the advantages of Ant Colony and Genetic Algorithm.Compared with the related work, the result shows that the HTS algorithm significantly surpasses the previous approaches in schedule length ratio and speedup.

  4. Machine Tool Series. Duty Task List.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This task list is intended for use in planning and/or evaluating a competency-based course to prepare machine tool, drill press, grinding machine, lathe, mill, and/or power saw operators. The listing is divided into six sections, with each one outlining the tasks required to perform the duties that have been identified for the given occupation.…

  5. Pleasantness of Creative Tasks and Creative Performance

    Science.gov (United States)

    Zenasni, Franck; Lubart, Todd

    2011-01-01

    To examine the impact of emotion on creative potential, experimental studies have typically focused on the impact of induced or spontaneous mood states on creative performance. In this report the relationship between the perceived pleasantness of tasks (using divergent thinking and story writing tasks) and creative performance was examined.…

  6. A Bilingual Advantage in Task Switching

    Science.gov (United States)

    Prior, Anat; MacWhinney, Brian

    2010-01-01

    This study investigated the possibility that lifelong bilingualism may lead to enhanced efficiency in the ability to shift between mental sets. We compared the performance of monolingual and fluent bilingual college students in a task-switching paradigm. Bilinguals incurred reduced switching costs in the task-switching paradigm when compared with…

  7. Students' Views of Example Generation Tasks

    Science.gov (United States)

    Breen, Sinead; O'Shea, Ann; Pfeiffer, Kirsten

    2016-01-01

    We report here on students' views of example generation tasks assigned to them in two first year undergraduate Calculus courses. The design and use of such tasks was undertaken as part of a project which aimed to afford students opportunities to develop their thinking skills and their conceptual understanding. In interviews with 10 students, we…

  8. The Keck Task Library (KTL)

    Science.gov (United States)

    Lupton, W. F.; Conrad, A. R.

    1992-01-01

    KTL is a set of routines which eases the job of writing applications which must interact with a variety of underlying sub-systems (known as services). A typical application is an X Window user interface coordinating telescope and instruments. In order to connect to a service, application code specifies a service name--typically an instrument name--and a style, which defines the way in which the application will interact with the service. Two styles are currently supported: keyword, where the application reads and writes named keywords and the resulting inter-task message traffic is hidden; and message, where the application deals directly with messages. The keyword style is intended mainly for user interfaces, and the message style is intended mainly for lower-level applications. KTL applications are event driven: a typical application first connects to all its desired services, then expresses interest in specified events. The application then enters an event dispatch loop in which it waits for events and calls the appropriate service's event-handling routine. Each event is associated with a call-back routine which is invoked when the event occurs. Call-back routines may (and typically do) interact with other sub-systems and KTL provides the means of doing so without blocking the application (vital for X Window user interfaces). This approach is a marriage of ideas culled from the X window, ADAM, Keck instrument, and Keck telescope control systems. A novel feature of KTL is that it knows nothing about any services or styles. Instead it defines a generic set of routines which must be implemented by all services and styles (essentially open(), ioctl(), read(), write(), event(), and close()) and activates sharable libraries at run-time. Services have been implemented (in both keyword and message styles) for HIRES (the Keck high resolution echelle spectrograph built by Lick Observatory), LWS (the Keck long wavelength spectrometer built by UC San Diego), and the Keck

  9. Task-specific dystonia: pathophysiology and management.

    Science.gov (United States)

    Sadnicka, Anna; Kassavetis, Panagiotis; Pareés, Isabel; Meppelink, Anne Marthe; Butler, Katherine; Edwards, Mark

    2016-09-01

    Task-specific dystonia is a form of isolated focal dystonia with the peculiarity of being displayed only during performance of a specific skilled motor task. This distinctive feature makes task-specific dystonia a particularly mysterious and fascinating neurological condition. In this review, we cover phenomenology and its increasingly broad-spectrum risk factors for the disease, critically review pathophysiological theories and evaluate current therapeutic options. We conclude by highlighting the unique features of task-specific dystonia within the wider concept of dystonia. We emphasise the central contribution of environmental risk factors, and propose a model by which these triggers may impact on the motor control of skilled movement. By viewing task-specific dystonia through this new lens which considers the disorder a modifiable disorder of motor control, we are optimistic that research will yield novel therapeutic avenues for this highly motivated group of patients. PMID:26818730

  10. Task mapping for non-contiguous allocations.

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Vitus Joseph; Bunde, David P. [Knox College, Galesburg, IL; Ebbers, Johnathan [Knox College, Galesburg, IL; Price, Nicholas W. [Knox College, Galesburg, IL; Swank, Matthew [Knox College, Galesburg, IL; Feer, Stefan P. [3M Health Information Systems, Inc., Wallingford, CT; Rhodes, Zachary D. [Allstate Corporation, Northbrook, IL

    2013-02-01

    This paper examines task mapping algorithms for non-contiguously allocated parallel jobs. Several studies have shown that task placement affects job running time for both contiguously and non-contiguously allocated jobs. Traditionally, work on task mapping either uses a very general model where the job has an arbitrary communication pattern or assumes that jobs are allocated contiguously, making them completely isolated from each other. A middle ground between these two cases is the mapping problem for non-contiguous jobs having a specific communication pattern. We propose several task mapping algorithms for jobs with a stencil communication pattern and evaluate them using experiments and simulations. Our strategies improve the running time of a MiniApp by as much as 30% over a baseline strategy. Furthermore, this improvement increases markedly with the job size, demonstrating the importance of task mapping as systems grow toward exascale.

  11. Learning to Model Task-Oriented Attention.

    Science.gov (United States)

    Zou, Xiaochun; Zhao, Xinbo; Wang, Jian; Yang, Yongjia

    2016-01-01

    For many applications in graphics, design, and human computer interaction, it is essential to understand where humans look in a scene with a particular task. Models of saliency can be used to predict fixation locations, but a large body of previous saliency models focused on free-viewing task. They are based on bottom-up computation that does not consider task-oriented image semantics and often does not match actual eye movements. To address this problem, we collected eye tracking data of 11 subjects when they performed some particular search task in 1307 images and annotation data of 2,511 segmented objects with fine contours and 8 semantic attributes. Using this database as training and testing examples, we learn a model of saliency based on bottom-up image features and target position feature. Experimental results demonstrate the importance of the target information in the prediction of task-oriented visual attention. PMID:27247561

  12. Reconsideration of the simulated work task situation

    DEFF Research Database (Denmark)

    Borlund, Pia; Schneider, Jesper Wiborg

    2010-01-01

    ’ of the simulated work task situations, which is emphasised through the need for tailoring of the simulated work task situations towards the group of study participant to ensure the depicted situations are realistic and interesting from the participants’ point of view. Likewise it seems that the......The present paper reports on the initial study and the preliminary findings of how the concept of simulated work task situation is reported used in the research literature. The overall objective of the study is in a systematic manner to learn how and for what types of evaluations the concept is...... applied. In particular we are interested to learn whether the recommendations for how to apply simulated work task situations are followed. The preliminary findings indicate a need for clarifications of the recommendations of how to use simulated work task situations. Particularly with respect to ‘realism...

  13. Error Sonification of a Complex Motor Task

    Directory of Open Access Journals (Sweden)

    Riener Robert

    2011-12-01

    Full Text Available Visual information is mainly used to master complex motor tasks. Thus, additional information providing augmented feedback should be displayed in other modalities than vision, e.g. hearing. The present work evaluated the potential of error sonification to enhance learning of a rowing-type motor task. In contrast to a control group receiving self-controlled terminal feedback, the experimental group could not significantly reduce spatial errors. Thus, motor learning was not enhanced by error sonification, although during the training the participant could benefit from it. It seems that the motor task was too slow, resulting in immediate corrections of the movement rather than in an internal representation of the general characteristics of the motor task. Therefore, further studies should elaborate the impact of error sonification when general characteristics of the motor tasks are already known.

  14. Learning to Model Task-Oriented Attention

    Science.gov (United States)

    Zou, Xiaochun; Zhao, Xinbo; Wang, Jian; Yang, Yongjia

    2016-01-01

    For many applications in graphics, design, and human computer interaction, it is essential to understand where humans look in a scene with a particular task. Models of saliency can be used to predict fixation locations, but a large body of previous saliency models focused on free-viewing task. They are based on bottom-up computation that does not consider task-oriented image semantics and often does not match actual eye movements. To address this problem, we collected eye tracking data of 11 subjects when they performed some particular search task in 1307 images and annotation data of 2,511 segmented objects with fine contours and 8 semantic attributes. Using this database as training and testing examples, we learn a model of saliency based on bottom-up image features and target position feature. Experimental results demonstrate the importance of the target information in the prediction of task-oriented visual attention. PMID:27247561

  15. Learning to Model Task-Oriented Attention

    Directory of Open Access Journals (Sweden)

    Xiaochun Zou

    2016-01-01

    Full Text Available For many applications in graphics, design, and human computer interaction, it is essential to understand where humans look in a scene with a particular task. Models of saliency can be used to predict fixation locations, but a large body of previous saliency models focused on free-viewing task. They are based on bottom-up computation that does not consider task-oriented image semantics and often does not match actual eye movements. To address this problem, we collected eye tracking data of 11 subjects when they performed some particular search task in 1307 images and annotation data of 2,511 segmented objects with fine contours and 8 semantic attributes. Using this database as training and testing examples, we learn a model of saliency based on bottom-up image features and target position feature. Experimental results demonstrate the importance of the target information in the prediction of task-oriented visual attention.

  16. EVA Task Timing and Timeline Planning

    Science.gov (United States)

    Looper, Christopher A.; Ney, Zane A.

    2007-01-01

    EVA timeline development occurs using task execution data generated through underwater training and simulation. This project collected task time data during final training events for several Space Shuttle and International Space Station missions and compared like task time data collected during on-orbit execution. Analysis was performed to compare types of activities and times required for each looking specifically for how activities can be accurately trained from a timeline planning perspective. The data revealed two significant aspects of flight timeline planning; Zero-g task times will match training times for activities that can be accurately simulated with appropriate fidelity hardware; and not all activities can be simulated sufficiently to produce training task times that will reflect required zero-g times. An approach for timeline planning utilizing this knowledge is also presented.

  17. Robot Task Commander with Extensible Programming Environment

    Science.gov (United States)

    Hart, Stephen W (Inventor); Yamokoski, John D. (Inventor); Wightman, Brian J (Inventor); Dinh, Duy Paul (Inventor); Gooding, Dustin R (Inventor)

    2014-01-01

    A system for developing distributed robot application-level software includes a robot having an associated control module which controls motion of the robot in response to a commanded task, and a robot task commander (RTC) in networked communication with the control module over a network transport layer (NTL). The RTC includes a script engine(s) and a GUI, with a processor and a centralized library of library blocks constructed from an interpretive computer programming code and having input and output connections. The GUI provides access to a Visual Programming Language (VPL) environment and a text editor. In executing a method, the VPL is opened, a task for the robot is built from the code library blocks, and data is assigned to input and output connections identifying input and output data for each block. A task sequence(s) is sent to the control module(s) over the NTL to command execution of the task.

  18. Analysis of the Discontinuities in Prioritized Tasks-Space Control Under Discrete Task Scheduling Operations

    OpenAIRE

    Keith, François; Wieber, Pierre-Brice; Mansard, Nicolas; Kheddar, Abderrahmane

    2011-01-01

    International audience This paper examines the control continuity in hierarchical task-space controllers. While the continuity is ensured for any a priori fixed number of tasks -even in ill-conditioned configurations-, the control resulting from a hierarchical stack-of-task computation may not be continuous under some discrete events. In particular, we study how the continuity of the stack-of-task control computation is affected under discreet scheduling operations such as on-the-fly prior...

  19. Secondary-task effects on sequence learning.

    Science.gov (United States)

    Heuer, H; Schmidtke, V

    1996-01-01

    With a repeated sequence of stimuli, performance in a serial reaction-time task improves more than with a random sequence. The difference has been taken as a measure of implicit sequence learning. Implicit sequence learning is impaired when a secondary task is added to the serial RT task. In the first experiment, secondary-task effects on different types of sequences were studied to test the hypothesis that the learning of unique sequences (where each sequence element has a unique relation to the following one) is not impaired by the secondary task, while the learning of ambiguous sequences is. The sequences were random up to a certain order of sequential dependencies, where they became deterministic. Contrary to the hypothesis, secondary-task effects on the learning of unique sequences were as strong or stronger than such effects on the learning of ambiguous sequences. In the second experiment a hybrid sequence (with unique as well as ambiguous transitions) was used with different secondary tasks. A visuo-spatial and a verbal memory task did not interfere with the learning of the sequence, but interference was observed with an auditory go/no-go task in which high- and low-pitched tones were presented after each manual response and a foot pedal had to be pressed in response to high-pitched tones. Thus, interference seems to be specific to certain secondary tasks and may be related to memory processes (but most likely not to visuo-spatial and verbal memory) or to the organizations of sequences, consistent with previous suggestions. PMID:8810586

  20. Team-computer interfaces in complex task environments

    Energy Technology Data Exchange (ETDEWEB)

    Terranova, M.

    1990-09-01

    This research focused on the interfaces (media of information exchange) teams use to interact about the task at hand. This report is among the first to study human-system interfaces in which the human component is a team, and the system functions as part of the team. Two operators dynamically shared a simulated fluid flow process, coordinating control and failure detection responsibilities through computer-mediated communication. Different computer interfaces representing the same system information were used to affect the individual operators' mental models of the process. Communication was identified as the most critical variable, consequently future research is being designed to test effective modes of communication. The results have relevance for the development of team-computer interfaces in complex systems in which responsibility must be shared dynamically among all members of the operation.

  1. Cognitive Complexity of Mathematics Instructional Tasks in a Taiwanese Classroom: An Examination of Task Sources

    Science.gov (United States)

    Hsu, Hui-Yu; Silver, Edward A.

    2014-01-01

    We examined geometric calculation with number tasks used within a unit of geometry instruction in a Taiwanese classroom, identifying the source of each task used in classroom instruction and analyzing the cognitive complexity of each task with respect to 2 distinct features: diagram complexity and problem-solving complexity. We found that…

  2. Achievement Goals in a Presentation Task: Performance Expectancy, Achievement Goals, State Anxiety, and Task Performance

    Science.gov (United States)

    Tanaka, Ayumi; Takehara, Takuma; Yamauchi, Hirotsugu

    2006-01-01

    The aims of the study were to test the linkages between achievement goals to task performance, as mediated by state anxiety arousal. Performance expectancy was also examined as antecedents of achievement goals. A presentation task in a computer practice class was used as achievement task. Fifty-three undergraduates (37 females and 16 males) were…

  3. 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…

  4. Musing on the Use of Dynamic Software and Mathematics Epistemology

    Science.gov (United States)

    Santos-Trigo, Manuel; Reyes-Rodriguez, Aaron; Espinosa-Perez, Hugo

    2007-01-01

    Different computational tools may offer teachers and students distinct opportunities in representing, exploring and solving mathematical tasks. In this context, we illustrate that the use of dynamic software (Cabri Geometry) helped high school teachers to think of and represent a particular task dynamically. In this process, the teachers had the…

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

    Directory of Open Access Journals (Sweden)

    Jutta eKray

    2013-12-01

    Full Text Available 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.

  6. Robust visual tracking via multi-task sparse learning

    KAUST Repository

    Zhang, Tianzhu

    2012-06-01

    In this paper, we formulate object tracking in a particle filter framework as a multi-task sparse learning problem, which we denote as Multi-Task Tracking (MTT). Since we model particles as linear combinations of dictionary templates that are updated dynamically, learning the representation of each particle is considered a single task in MTT. By employing popular sparsity-inducing p, q mixed norms (p D; 1), we regularize the representation problem to enforce joint sparsity and learn the particle representations together. As compared to previous methods that handle particles independently, our results demonstrate that mining the interdependencies between particles improves tracking performance and overall computational complexity. Interestingly, we show that the popular L 1 tracker [15] is a special case of our MTT formulation (denoted as the L 11 tracker) when p q 1. The learning problem can be efficiently solved using an Accelerated Proximal Gradient (APG) method that yields a sequence of closed form updates. As such, MTT is computationally attractive. We test our proposed approach on challenging sequences involving heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that MTT methods consistently outperform state-of-the-art trackers. © 2012 IEEE.

  7. Hand Interface in Traditional Modeling and Animation Tasks

    Institute of Scientific and Technical Information of China (English)

    孙汉秋

    1996-01-01

    3-D task space in modeling and animation is usually reduced to the separate control dimensions supported by conventional interactive devices.This limitation maps only partial view of the problem to the device space at a time,and results in tedious and unnatural interface of control.This paper uses the DataGlove interface for modeling and animating scene behaviors.The modeling interface selects,scales,rotates,translates,copies and deletes the instances of the primitives.These basic modeling processes are directly performed in the task space,using hand shapes and motions.Hand shapes are recognized as discrete states that trigger the commands,and hand motion are mapped to the movement of a selected instance.The interactions through hand interface place the user as a participant in the process of behavior simulation.Both event triggering and role switching of hand are experimented in simulation.The event mode of hand triggers control signals or commands through a menu interface.The object mode of hand simulates itself as an object whose appearance or motion influences the motions of other objects in scene.The involvement of hand creates a diversity of dynamic situations for testing variable scene behaviors.Our experiments have shown the potential use of this interface directly in the 3-D modeling and animation task space.

  8. Nintendo Wii Balance Board is sensitive to effects of visual tasks on standing sway in healthy elderly adults.

    Science.gov (United States)

    Koslucher, Frank; Wade, Michael G; Nelson, Brent; Lim, Kelvin; Chen, Fu-Chen; Stoffregen, Thomas A

    2012-07-01

    Research has shown that the Nintendo Wii Balance Board (WBB) can reliably detect the quantitative kinematics of the center of pressure in stance. Previous studies used relatively coarse manipulations (1- vs. 2-leg stance, and eyes open vs. closed). We sought to determine whether the WBB could reliably detect postural changes associated with subtle variations in visual tasks. Healthy elderly adults stood on a WBB while performing one of two visual tasks. In the Inspection task, they maintained their gaze within the boundaries of a featureless target. In the Search task, they counted the occurrence of designated target letters within a block of text. Consistent with previous studies using traditional force plates, the positional variability of the center of pressure was reduced during performance of the Search task, relative to movement during performance of the Inspection task. Using detrended fluctuation analysis, a measure of movement dynamics, we found that COP trajectories were more predictable during performance of the Search task than during performance of the Inspection task. The results indicate that the WBB is sensitive to subtle variations in both the magnitude and dynamics of body sway that are related to variations in visual tasks engaged in during stance. The WBB is an inexpensive, reliable technology that can be used to evaluate subtle characteristics of body sway in large or widely dispersed samples. PMID:22748469

  9. Improved intertask coordination after extensive dual-task practice

    OpenAIRE

    Liepelt, R.; Strobach, T.; Frensch, P.; Schubert, T.

    2011-01-01

    This study examines whether an improved intertask coordination skill is acquired during extensive dual-task training and whether it can be transferred to a new dual-task situation. Participants practised a visual–manual task and an auditory–vocal task. These tasks were trained in two groups matched in dual-task performance measures before practice: a single-task practice group and a hybrid practice group (including single-task and dual-task practice). After practice, the single-task practice ...

  10. Dynamic multi DAG scheduling algorithm for optical grid environment

    Science.gov (United States)

    Zhu, Liying; Sun, Zhenyu; Guo, Wei; Jin, Yaohui; Sun, Weiqiang; Hu, Weisheng

    2007-11-01

    Facing the evolvement of the Optical Grid technology, dynamic task scheduling can largely improve the efficiency of the Grid environment under the real circumstances. We propose a Serve On Time (SOT) algorithm - based on the idea of combining all the dynamic multi tasks so that all the tasks will obtain the rights to be served as soon as possible. We then introduce the basic First Come First Serve (FCFS) algorithm. A simulation will show the advantage of SOT.

  11. Dual Task Impairments in Vascular Dementia

    Directory of Open Access Journals (Sweden)

    Kate Inasaridze

    2010-01-01

    Full Text Available Several studies have shown that people with Alzheimer's disease (AD demonstrate difficulties in doing two things at once or 'dual-tasking' and that this dual task impairment is insensitive to normal ageing, chronic depression or prodromal conditions like Mild Cognitive Impairment. It is not known, however, if this impairment is specific to AD, or also present in other dementias, such as vascular dementia (VaD. In this study 15 people with VaD, 25 healthy age-matched and 25 healthy young controls were assessed using a paper and pencil dual tasking paradigm and several measures of working and episodic memory. Age had no effect on dual task performance, but the VaD patients demonstrated a significant impairment in dual tasking ability. Performance on the memory measures was instead affected by age with a further deterioration in the VaD patients. Both dual tasking and memory ability were significantly correlated with disease severity, as assessed by the MMSE. These results indicate that performance on the dual task could be a specific indicator of pathological ageing.

  12. Stability control during the performance of a simultaneous obstacle avoidance and auditory Stroop task.

    Science.gov (United States)

    Worden, Timothy A; Vallis, Lori Ann

    2016-02-01

    Navigation through complex environments requires a greater degree of control and attentional resources from the central nervous system to ensure postural stability and efficient goal completion as compared to quiet standing or unobstructed walking. Furthermore, when a cognitive task is also performed in a dual-task scenario, additional resources may be required. The purpose of the current study was to examine the effects of performing a concurrent cognitive (auditory Stroop task) and complex locomotor task (with a stationary or dynamic obstacle) on frontal plane stability control quantified using a margin of stability (MOS) measure. Fourteen healthy young adults performed 40 dual-task trials (randomized in a balanced design for auditory Stroop congruency and obstacle movement). Results indicated that frontal plane MOS was greatest for the obstacle crossing step and was greater for the dynamic obstacle as compared to the stationary obstacle. Conversely, frontal plane MOS was the smallest for the pre-crossing step, indicating that this point in the obstacle stepping strategy may be the least stable. No effect of cognitive task difficulty was observed for any of the experimental conditions, providing support for a 'posture-first' strategy. These findings suggest that an increase in stability is prioritized for the obstacle crossing step, potentially at the expense of reduced stability in the step immediately preceding the obstacle. These results have implications for better understanding how the CNS controls stability at different events during the obstacle crossing strategy in a complex environment. PMID:26487180

  13. Task Allocation and Path Planning for Collaborative Autonomous Underwater Vehicles Operating through an Underwater Acoustic Network

    Directory of Open Access Journals (Sweden)

    Yueyue Deng

    2013-01-01

    Full Text Available Dynamic and unstructured multiple cooperative autonomous underwater vehicle (AUV missions are highly complex operations, and task allocation and path planning are made significantly more challenging under realistic underwater acoustic communication constraints. This paper presents a solution for the task allocation and path planning for multiple AUVs under marginal acoustic communication conditions: a location-aided task allocation framework (LAAF algorithm for multitarget task assignment and the grid-based multiobjective optimal programming (GMOOP mathematical model for finding an optimal vehicle command decision given a set of objectives and constraints. Both the LAAF and GMOOP algorithms are well suited in poor acoustic network condition and dynamic environment. Our research is based on an existing mobile ad hoc network underwater acoustic simulator and blind flooding routing protocol. Simulation results demonstrate that the location-aided auction strategy performs significantly better than the well-accepted auction algorithm developed by Bertsekas in terms of task-allocation time and network bandwidth consumption. We also demonstrate that the GMOOP path-planning technique provides an efficient method for executing multiobjective tasks by cooperative agents with limited communication capabilities. This is in contrast to existing multiobjective action selection methods that are limited to networks where constant, reliable communication is assumed to be available.

  14. A Scheduling Algorithm for Cloud Computing System Based on the Driver of Dynamic Essential Path

    Science.gov (United States)

    Xie, Zhiqiang; Shao, Xia; Xin, Yu

    2016-01-01

    To solve the problem of task scheduling in the cloud computing system, this paper proposes a scheduling algorithm for cloud computing based on the driver of dynamic essential path (DDEP). This algorithm applies a predecessor-task layer priority strategy to solve the problem of constraint relations among task nodes. The strategy assigns different priority values to every task node based on the scheduling order of task node as affected by the constraint relations among task nodes, and the task node list is generated by the different priority value. To address the scheduling order problem in which task nodes have the same priority value, the dynamic essential long path strategy is proposed. This strategy computes the dynamic essential path of the pre-scheduling task nodes based on the actual computation cost and communication cost of task node in the scheduling process. The task node that has the longest dynamic essential path is scheduled first as the completion time of task graph is indirectly influenced by the finishing time of task nodes in the longest dynamic essential path. Finally, we demonstrate the proposed algorithm via simulation experiments using Matlab tools. The experimental results indicate that the proposed algorithm can effectively reduce the task Makespan in most cases and meet a high quality performance objective. PMID:27490901

  15. Energy-efficient scheduling for hybrid tasks in control devices for the Internet of Things.

    Science.gov (United States)

    Gao, Zhigang; Wu, Yifan; Dai, Guojun; Xia, Haixia

    2012-01-01

    In control devices for the Internet of Things (IoT), energy is one of the critical restriction factors. Dynamic voltage scaling (DVS) has been proved to be an effective method for reducing the energy consumption of processors. This paper proposes an energy-efficient scheduling algorithm for IoT control devices with hard real-time control tasks (HRCTs) and soft real-time tasks (SRTs). The main contribution of this paper includes two parts. First, it builds the Hybrid tasks with multi-subtasks of different function Weight (HoW) task model for IoT control devices. HoW describes the structure of HRCTs and SRTs, and their properties, e.g., deadlines, execution time, preemption properties, and energy-saving goals, etc. Second, it presents the Hybrid Tasks' Dynamic Voltage Scaling (HTDVS) algorithm. HTDVS first sets the slowdown factors of subtasks while meeting the different real-time requirements of HRCTs and SRTs, and then dynamically reclaims, reserves, and reuses the slack time of the subtasks to meet their ideal energy-saving goals. Experimental results show HTDVS can reduce energy consumption about 10%-80% while meeting the real-time requirements of HRCTs, HRCTs help to reduce the deadline miss ratio (DMR) of systems, and HTDVS has comparable performance with the greedy algorithm and is more favorable to keep the subtasks' ideal speeds. PMID:23112659

  16. Optimal control model of arm configuration in a reaching task

    Science.gov (United States)

    Yamaguchi, Gary T.; Kakavand, Ali

    1996-05-01

    It was hypothesized that the configuration of the upper limb during a hand static positioning task could be predicted using a dynamic musculoskeletal model and an optimal control routine. Both rhesus monkey and human upper extremity models were formulated, and had seven degrees of freedom (7-DOF) and 39 musculotendon pathways. A variety of configurations were generated about a physiologically measured configuration using the dynamic models and perturbations. The pseudoinverse optimal control method was applied to compute the minimum cost C at each of the generated configurations. Cost function C is described by the Crowninshield-Brand (1981) criterion which relates C (the sum of muscle stresses squared) to the endurance time of a physiological task. The configuration with the minimum cost was compared to the configurations chosen by one monkey (four trials) and by eight human subjects (eight trials each). Results are generally good, but not for all joint angles, suggesting that muscular effort is likely to be one major factor in choosing a preferred static arm posture.

  17. 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

    correction were used to evaluate sex differences. RESULTS: Statistically significant (p<0.05) sex 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......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 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...

  18. Computerized management of plant intervention tasks

    International Nuclear Information System (INIS)

    The concept of 'computerized management' of plant intervention tasks was developed by TRACTEBEL in 1983 for the Belgian power plants of ELECTRABEL. The main objective of the 'Computerized Management of Plant Intervention Tasks' is to help the staff of a nuclear or a conventional power plant in planning, organizing, and carrying out any (preventive or corrective) maintenance task. It consists of a group of interconnected functional modules acting on a unique and homogeneous data base. A short description of 3 modules is given, i.e., the 'User' Module, the 'Equipment' Module and the 'Periodic Procedure' Module. (Z.S.)

  19. Effort - Final technical report on task 3

    DEFF Research Database (Denmark)

    Bay, Niels; Henningsen, Poul; Eriksen, Morten; Lindegren, Maria

    The present report is documentation for the work carried out at DTU on the Brite/Euram project No. BE96-3340, contract No. BRPR-CT97-0398, with the title Enhanced Framework for forging design using reliable three-dimensional simulation (EFFORTS). The objective of task 3 is to determine data on the...... tool/workpiece interface conditions. The task includes the following four sub-tasks: Subtask 3.1 Simulative testing of friction in cold forming Subtask 3.2 Simulative testing of friction in warm and hot forming Subtask 3.3 Validation of measured friction values by process tests Subtask 3.4 Heat...

  20. Learning to Model Task-Oriented Attention

    OpenAIRE

    Xiaochun Zou; Xinbo Zhao; Jian Wang; Yongjia Yang

    2016-01-01

    For many applications in graphics, design, and human computer interaction, it is essential to understand where humans look in a scene with a particular task. Models of saliency can be used to predict fixation locations, but a large body of previous saliency models focused on free-viewing task. They are based on bottom-up computation that does not consider task-oriented image semantics and often does not match actual eye movements. To address this problem, we collected eye tracking data of 11 ...

  1. An approach to elemental task learning

    Energy Technology Data Exchange (ETDEWEB)

    Belmans, P

    1990-01-01

    In this article we deal with the automated learning of tasks by a robotic system through observation of a human operator. Particularly, we explain what is meant by a learning ability in autonomous robots and in teleoperation systems, where several operators and several machines may work in cooperation to perform tasks. We discuss different approaches to learning in these systems and outline the features of the models they are based upon. This leads us to choose an analytical model suited for tasks analysis. We then present the software architecture for our proposed approach and show the first results obtained on sample tests. 5 refs., 9 figs.

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

    OpenAIRE

    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...

  3. Higher, faster, stronger: the effect of dynamic stimuli on response preparation and CNV amplitude.

    Science.gov (United States)

    Linssen, A M W; Sambeth, A; Riedel, W J; Vuurman, E F P M

    2013-01-15

    The contingent negative variation (CNV) is a slow negative shift in the electroencephalogram (EEG), observed during response preparation. To optimalize the CNV paradigm, this study developed a task using dynamic stimuli and next combined this task with a Go/No-go test. In the first experiment, 19 healthy volunteers were subjected to the classic Traffic light (TL) task and the new dynamic Lines task. In the Lines task, response time was faster and CNV amplitude was larger compared to the TL task. In the second experiment, 20 healthy participants were tested on a Go/No-go version of the Lines task. Response times increased as the probability of response requirement decreased. CNV amplitude was larger when probability of response requirement was higher. In conclusion, the dynamic task promotes response preparation. The new tasks may be especially valuable in groups with attention difficulties (i.e. elderly or ADHD patients). PMID:23041181

  4. Multiobjective Resource-Constrained Project Scheduling with a Time-Varying Number of Tasks

    Directory of Open Access Journals (Sweden)

    Manuel Blanco Abello

    2014-01-01

    Full Text Available In resource-constrained project scheduling (RCPS problems, ongoing tasks are restricted to utilizing a fixed number of resources. This paper investigates a dynamic version of the RCPS problem where the number of tasks varies in time. Our previous work investigated a technique called mapping of task IDs for centroid-based approach with random immigrants (McBAR that was used to solve the dynamic problem. However, the solution-searching ability of McBAR was investigated over only a few instances of the dynamic problem. As a consequence, only a small number of characteristics of McBAR, under the dynamics of the RCPS problem, were found. Further, only a few techniques were compared to McBAR with respect to its solution-searching ability for solving the dynamic problem. In this paper, (a the significance of the subalgorithms of McBAR is investigated by comparing McBAR to several other techniques; and (b the scope of investigation in the previous work is extended. In particular, McBAR is compared to a technique called, Estimation Distribution Algorithm (EDA. As with McBAR, EDA is applied to solve the dynamic problem, an application that is unique in the literature.

  5. Interaction between articulatory gestures and inner speech in a counting task.

    Science.gov (United States)

    Cefidekhanie, Ali Hadian; Savariaux, Christophe; Sato, Marc; Schwartz, Jean-Luc

    2014-10-01

    Interaction between covert and overt orofacial gestures has been poorly studied apart from old and rather qualitative experiments. The question deserves special interest in the context of the debate between auditory and motor theories of speech perception, where dual tasks may be of great interest. It is shown here that dynamic mandible and lips movement produced by a participant result in strong and stable perturbations to an inner speech counting task that has to be realized at the same time, while static orofacial configurations and static or dynamic manual actions produce no perturbation. This enables the authors to discuss how such kinds of orofacial perturbations could be introduced in dual task paradigms to assess the role of motor processes in speech perception. PMID:25324087

  6. Marital Satisfaction, Job Satisfaction, and Task Distribution in the Homemaker Job

    Science.gov (United States)

    Gross, Ronald H.; Arvey, Richard D.

    1977-01-01

    Serveral facets of the homemaker job were analyzed in terms of the dynamic relationship between husband and wife. Husband and wife pairs (N=71) completed a questionnaire which assessed satisfaction with the homemaker job, marital satisfaction, distribution of responsibility for homemaker tasks between husband and wife, and other variables. (Author)

  7. Non-stationary strategies in the resources allocation task of IT project

    OpenAIRE

    Гриша, Олена Василівна

    2011-01-01

    Article deals with distributing of labour resources of IT project choosing of the non-stationary mixed strategy. The simulation model of research of credible implementation of project is given in the conditions of action of factor of novelty of executable works, changes maturity of command and dynamics of risks. The task of optimization of the non-stationary mixed strategy is decided.

  8. The Impact of Task Type and Cognitive Style on Vocabulary Learning

    Science.gov (United States)

    Nezhad, Gholam Reza Haji Pour; Shokrpour, Nasrin

    2012-01-01

    Vocabulary knowledge influences the learners' performance so remarkably that success in all language skills is closely related to it. This vital role necessitates studies focusing on the most effective programs of teaching vocabulary. In this study, we aimed to explore the impact of static versus dynamic task type and the possible interaction with…

  9. Pyramid Lake Task Force : Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Pyramid Lake Task Force was created to address Pyramid Lake’s recession and recommend possible solutions that would consider both the needs for preserving the...

  10. Task-based Research and Language Pedagogy.

    Science.gov (United States)

    Ellis, Rod

    2000-01-01

    Examines theoretical views of language use, learning, and teaching that underlie the work on tasks. Two broad and disparate views are identified: the psycholinguistic perspective and a perspective based on sociocultural theory. (Author/VWL)

  11. Enhanced Memetic Algorithm for Task Scheduling

    Science.gov (United States)

    Padmavathi, S.; Shalinie, S. Mercy; Someshwar, B. C.; Sasikumar, T.

    Scheduling tasks onto the processors of a parallel system is a crucial part of program parallelization. Due to the NP-hardness of the task scheduling problem, scheduling algorithms are based on heuristics that try to produce good rather than optimal schedules. This paper proposes a Memetic algorithm with Tabu search and Simulated Annealing as local search for solving Task scheduling problem considering communication contention. This problem consists of finding a schedule for a general task graph to be executed on a cluster of workstations and hence the schedule length can be minimized. Our approach combines local search (by self experience) and global search (by neighboring experience) possessing high search efficiency. The proposed approach is compared with existing list scheduling heuristics. The numerical results clearly indicate that our proposed approach produces solutions which are closer to optimality and/or better quality than the existing list scheduling heuristics.

  12. Decision Making System for Operative Tasks

    OpenAIRE

    Shakah, G.; Krasnoproshin, V. V.; Valvachev, A. N.

    2009-01-01

    Actual problems of construction of computer systems for operative tasks of decision making are considered. possibilities of solving the problems on the basis of the theory of active systems (tas) are investigated.

  13. Task force report on computerized tomographic scanners

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    Computerized axial tomography (CAT) scanning was the focus of a task force established by the Bergen-Passaic Health Systems Agency in New Jersey. The task force reviewed the literature on CAT technology and its applications, surveyed four northeastern hospitals with operating CAT scanning installations, and created three working subcommittees which produced written reports. It was agreed by task force members that certain criteria should be used when evaluating applications for CAT scanners, e.g., service area, staff resources, emergency room activity, radiotherapy, 24-hour scanner coverage, the medically indigent, and cost. Overall, it was determined that CAT is a proven diagnostic tool of significant value and that it should be available to residents of the Bergen-Passaic health service area. Since the CAT field is rapidly evolving and changing, however, it was not possible to define quantitatively the long-term need for and supply of CAT scanners in the region. Appendixes present supporting data on the task force findings.

  14. An ergonomic task analysis of spinal anaesthesia.

    LENUS (Irish Health Repository)

    Ajmal, Muhammad

    2009-12-01

    Ergonomics is the study of physical interaction between humans and their working environment. The objective of this study was to characterize the performance of spinal anaesthesia in an acute hospital setting, applying ergonomic task analysis.

  15. A Task-driven Grammar Refactoring Algorithm

    Directory of Open Access Journals (Sweden)

    Ivan Halupka

    2012-01-01

    Full Text Available This paper presents our proposal and the implementation of an algorithm for automated refactoring of context-free grammars. Rather than operating under some domain-specific task, in our approach refactoring is perfomed on the basis of a refactoring task defined by its user. The algorithm and the corresponding refactoring system are called mARTINICA. mARTINICA is able to refactor grammars of arbitrary size and structural complexity. However, the computation time needed to perform a refactoring task with the desired outcome is highly dependent on the size of the grammar. Until now, we have successfully performed refactoring tasks on small and medium-size grammars of Pascal-like languages and parts of the Algol-60 programming language grammar. This paper also briefly introduces the reader to processes occurring in grammar refactoring, a method for describing desired properties that a refactored grammar should fulfill, and there is a discussion of the overall significance of grammar refactoring.

  16. Electrophysiological Evidence for Domain-general Processes in Task-switching

    Directory of Open Access Journals (Sweden)

    Mariagrazia eCapizzi

    2016-03-01

    Full Text Available The ability to flexibly switch between tasks is a hallmark of cognitive control. Despite previous studies that have investigated whether different task-switching types would be mediated by distinct or overlapping neural mechanisms, no definitive consensus has been reached on this question yet. Here, we aimed at directly addressing this issue by recording the event-related potentials (ERPs elicited by two types of task-switching occurring in the context of spatial and verbal cognitive domains. Source analysis was also applied to the ERP data in order to track the spatial dynamics of brain activity underlying task-switching abilities. In separate blocks of trials, participants had to perform either spatial or verbal switching tasks both of which employed the same type of stimuli. The ERP analysis, which was carried out through a channel- and time-uninformed mass univariate approach, showed no significant differences between the spatial and verbal domains in the modulation of switch and repeat trials. Specifically, relative to repeat trials, switch trials in both domains were associated with a first larger positivity developing over left parieto-occipital electrodes and with a subsequent larger negativity distributed over mid-left fronto-central sites. The source analysis reconstruction for the two ERP components complemented these findings by highlighting the involvement of left-lateralized prefrontal areas in task-switching. Overall, our results join and extend recent research confirming the existence of left-lateralized domain-general task-switching processes.

  17. Electrophysiological Evidence for Domain-General Processes in Task-Switching.

    Science.gov (United States)

    Capizzi, Mariagrazia; Ambrosini, Ettore; Arbula, Sandra; Mazzonetto, Ilaria; Vallesi, Antonino

    2016-01-01

    The ability to flexibly switch between tasks is a hallmark of cognitive control. Despite previous studies that have investigated whether different task-switching types would be mediated by distinct or overlapping neural mechanisms, no definitive consensus has been reached on this question yet. Here, we aimed at directly addressing this issue by recording the event-related potentials (ERPs) elicited by two types of task-switching occurring in the context of spatial and verbal cognitive domains. Source analysis was also applied to the ERP data in order to track the spatial dynamics of brain activity underlying task-switching abilities. In separate blocks of trials, participants had to perform either spatial or verbal switching tasks both of which employed the same type of stimuli. The ERP analysis, which was carried out through a channel- and time-uninformed mass univariate approach, showed no significant differences between the spatial and verbal domains in the modulation of switch and repeat trials. Specifically, relative to repeat trials, switch trials in both domains were associated with a first larger positivity developing over left parieto-occipital electrodes and with a subsequent larger negativity distributed over mid-left fronto-central sites. The source analysis reconstruction for the two ERP components complemented these findings by highlighting the involvement of left-lateralized prefrontal areas in task-switching. Overall, our results join and extend recent research confirming the existence of left-lateralized domain-general task-switching processes. PMID:27047366

  18. Load Balancing in Cloud Computing Environment Using Improved Weighted Round Robin Algorithm for Nonpreemptive Dependent Tasks.

    Science.gov (United States)

    Devi, D Chitra; Uthariaraj, V Rhymend

    2016-01-01

    Cloud computing uses the concepts of scheduling and load balancing to migrate tasks to underutilized VMs for effectively sharing the resources. The scheduling of the nonpreemptive tasks in the cloud computing environment is an irrecoverable restraint and hence it has to be assigned to the most appropriate VMs at the initial placement itself. Practically, the arrived jobs consist of multiple interdependent tasks and they may execute the independent tasks in multiple VMs or in the same VM's multiple cores. Also, the jobs arrive during the run time of the server in varying random intervals under various load conditions. The participating heterogeneous resources are managed by allocating the tasks to appropriate resources by static or dynamic scheduling to make the cloud computing more efficient and thus it improves the user satisfaction. Objective of this work is to introduce and evaluate the proposed scheduling and load balancing algorithm by considering the capabilities of each virtual machine (VM), the task length of each requested job, and the interdependency of multiple tasks. Performance of the proposed algorithm is studied by comparing with the existing methods. PMID:26955656

  19. An Architecture for Robot Assemblt Task Planning

    DEFF Research Database (Denmark)

    Sun, Hongyan

    1999-01-01

    This paper discusses an integrated robot assembly task planning system architecture. In such an integrated system, the robot motion commands produced from the planning system can be validated before done-loading for actual execution.......This paper discusses an integrated robot assembly task planning system architecture. In such an integrated system, the robot motion commands produced from the planning system can be validated before done-loading for actual execution....

  20. Extended task space control for robotic manipulators

    Science.gov (United States)

    Backes, Paul G.; Long, Mark K.

    1993-03-01

    The invention is a method of operating a robot in successive sampling intervals to perform a task. The robot is comprised of joints and joint actuators, which make use of actuator control loops. The actuators decompose the task into behavior forces that are comprised of accelerations, velocities, and positions of robotic behaviors. The actuator accelerations, velocities, and positions of the current sampling interval are stored for use during the next sampling interval.