WorldWideScience

Sample records for sequential time perception

  1. Enhancing sequential time perception and storytelling ability of deaf and hard of hearing children.

    Science.gov (United States)

    Ingber, Sara; Eden, Sigal

    2011-01-01

    A 3-month intervention was conducted to enhance the sequential time perception and storytelling ability of young children with hearing loss. The children were trained to arrange pictorial episodes of temporal scripts and tell the stories they created. Participants (N = 34, aged 4-7 years) were divided into 2 groups based on whether their spoken-language gap was more or less than 1 year compared to age norms. They completed A. Kaufman and N. Kaufman's (1983) picture series subtest and Guralnik's (1982) storytelling test at pretest and posttest. Measures demonstrated significant improvement in sequential time and storytelling achievement postintervention. Three of the examined demographic variables revealed correlations: Participants with genetic etiology showed greater improvement in time sequencing and storytelling than participants with unknown etiology; early onset of treatment correlated with better achievement in time sequencing; cochlear implant users showed greater storytelling improvement than hearing aid users.

  2. Multimodal sensory integration during sequential eating--linking chewing activity, aroma release, and aroma perception over time.

    Science.gov (United States)

    Leclercq, Ségolène; Blancher, Guillaume

    2012-10-01

    The respective effects of chewing activity, aroma release from a gelled candy, and aroma perception were investigated. Specifically, the study aimed at 1) comparing an imposed chewing and swallowing pattern (IP) and free protocol (FP) on panelists for in vivo measurements, 2) investigating carryover effects in sequential eating, and 3) studying the link between instrumental data and their perception counterpart. Chewing activity, in-nose aroma concentration, and aroma perception over time were measured by electromyography, proton transfer reaction-mass spectrometry, and time intensity, respectively. Model gel candies were flavored at 2 intensity levels (low-L and high-H). The panelists evaluated 3 sequences (H then H, H then L, and L then H) in duplicates with both IP and FP. They scored aroma intensity over time while their in-nose aroma concentrations and their chewing activity were measured. Overall, only limited advantages were found in imposing a chewing and swallowing pattern for instrumental and sensory data. In addition, the study highlighted the role of brain integration on perceived intensity and dynamics of perception, in the framework of sequential eating without rinsing. Because of the presence of adaptation phenomena, contrast effect, and potential taste and texture cross-modal interaction with aroma perception, it was concluded that dynamic in-nose concentration data provide only one part of the perception picture and therefore cannot be used alone in prediction models.

  3. The Effect of 3D Virtual Reality on Sequential Time Perception among Deaf and Hard-of-Hearing Children

    Science.gov (United States)

    Eden, Sigal

    2008-01-01

    Over the years deaf and hard-of-hearing children have been reported as having difficulty with time conception and, in particular, the proper arrangement of events in a logical, temporal order. The research examined whether deaf and hard-of-hearing children perceive a temporal sequence differently under different representational modes. We compared…

  4. Sequential motor skill: cognition, perception and action

    NARCIS (Netherlands)

    Ruitenberg, M.F.L.

    2013-01-01

    Discrete movement sequences are assumed to be the building blocks of more complex sequential actions that are present in our everyday behavior. The studies presented in this dissertation address the (neuro)cognitive underpinnings of such movement sequences, in particular in relationship to the role

  5. A continuous-time neural model for sequential action.

    Science.gov (United States)

    Kachergis, George; Wyatte, Dean; O'Reilly, Randall C; de Kleijn, Roy; Hommel, Bernhard

    2014-11-05

    Action selection, planning and execution are continuous processes that evolve over time, responding to perceptual feedback as well as evolving top-down constraints. Existing models of routine sequential action (e.g. coffee- or pancake-making) generally fall into one of two classes: hierarchical models that include hand-built task representations, or heterarchical models that must learn to represent hierarchy via temporal context, but thus far lack goal-orientedness. We present a biologically motivated model of the latter class that, because it is situated in the Leabra neural architecture, affords an opportunity to include both unsupervised and goal-directed learning mechanisms. Moreover, we embed this neurocomputational model in the theoretical framework of the theory of event coding (TEC), which posits that actions and perceptions share a common representation with bidirectional associations between the two. Thus, in this view, not only does perception select actions (along with task context), but actions are also used to generate perceptions (i.e. intended effects). We propose a neural model that implements TEC to carry out sequential action control in hierarchically structured tasks such as coffee-making. Unlike traditional feedforward discrete-time neural network models, which use static percepts to generate static outputs, our biological model accepts continuous-time inputs and likewise generates non-stationary outputs, making short-timescale dynamic predictions. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  6. THE DEVELOPMENT OF SPECIAL SEQUENTIALLY-TIMED

    Directory of Open Access Journals (Sweden)

    Stanislav LICHOROBIEC

    2016-06-01

    Full Text Available This article documents the development of the noninvasive use of explosives during the destruction of ice mass in river flows. The system of special sequentially-timed charges utilizes the increase in efficiency of cutting charges by covering them with bags filled with water, while simultaneously increasing the effect of the entire system of timed charges. Timing, spatial combinations during placement, and the linking of these charges results in the loosening of ice barriers on a frozen waterway, while at the same time regulating the size of the ice fragments. The developed charges will increase the operability and safety of IRS units.

  7. Time scale of random sequential adsorption.

    Science.gov (United States)

    Erban, Radek; Chapman, S Jonathan

    2007-04-01

    A simple multiscale approach to the diffusion-driven adsorption from a solution to a solid surface is presented. The model combines two important features of the adsorption process: (i) The kinetics of the chemical reaction between adsorbing molecules and the surface and (ii) geometrical constraints on the surface made by molecules which are already adsorbed. The process (i) is modeled in a diffusion-driven context, i.e., the conditional probability of adsorbing a molecule provided that the molecule hits the surface is related to the macroscopic surface reaction rate. The geometrical constraint (ii) is modeled using random sequential adsorption (RSA), which is the sequential addition of molecules at random positions on a surface; one attempt to attach a molecule is made per one RSA simulation time step. By coupling RSA with the diffusion of molecules in the solution above the surface the RSA simulation time step is related to the real physical time. The method is illustrated on a model of chemisorption of reactive polymers to a virus surface.

  8. Perception, time of perception, perception of the time

    Directory of Open Access Journals (Sweden)

    Barata, André

    2009-04-01

    Full Text Available From a conceptual point of view, time is independent of its experience. That is: it can be given a conceptual description of time without any reference to terms related to the subjective consciousness of time. But concerning a phenomenology of that subjective experience of time, it can it be showed that such experience of time is, in itself, temporal. The very same terms employed in a conceptual description of time – terms like “change” and “duration”– are implied in the phenomenological description of every perception, including perception of time. This authorizes a characterization of subjective time experience as subjective time. At last, based on temporal nature of perception of time, I will suggest an explanation for our common experience of asymmetries subjective time and objective time.Desde un punto de vista conceptual, el tiempo es independiente respecto de la experiencia del tiempo. Es decir: puede darse una descripción conceptual del tiempo sin referencia ninguna a términos relacionados con la conciencia subjetiva del tiempo. Pero en lo concerniente a una fenomenología de esa experiencia subjetiva del tiempo, puede revelarse que tal experiencia de tiempo es, ella en sí misma, temporal? Los mismísimos términos empleados en una descripción conceptual del tiempo, como “cambio” y “duración”, están implicados en la descripción fenomenológica de toda percepción, incluida la percepción del tiempo. Esto autoriza una caracterización de la experiencia subjetiva del tiempo como tiempo subjetivo. Finalmente, sobre la base de la naturaleza temporal de la percepción del tiempo, sugeriré una explicación racional de nuestra experiencia común de asimetrías entre el tiempo subjetivo y el tiempo objetivo.

  9. Sequential and Biomechanical Factors Constrain Timing and Motion in Tapping

    NARCIS (Netherlands)

    Loehr, J.D.; Palmer, C.

    2009-01-01

    The authors examined how timing accuracy in tapping sequences is influenced by sequential effects of preceding finger movements and biomechanical interdependencies among fingers. Skilled pianists tapped Sequences at 3 rates; in each sequence, a finger whose motion was more or less independent of

  10. Time Perception and Psychiatric Disorders

    Directory of Open Access Journals (Sweden)

    Hatice Ceviz

    2013-09-01

    Full Text Available Time perception is an ability which we use in every moment of daily life, that guides the formation and continuation of our behaviors and from an evolutionary perspective ensures survival. Internal clock models help us to understand time perception. Time perception is known to vary between individuals and particular situations. This variability is explained with the mechanisms which is associated with the processes related to attention, the speed of the internal clock and the memory unit. It is suggested that time perception is mainly associated with the activities of dopamine and acetylcholine. Some dopaminergic psychoactive substances like cocaine and amphetamine have all been shown to change time perception by increasing the speed of internal clock while on the other hand some antipsychotic drugs make an opposite change in time perception by descreasing the speed of the clock. Similarly, time perception is affected in some psychiatric disorders and an ethiopathological relationship between time perception disturbances and psychiatric disorders is suggested. In this article time perception changes in schizophrenia, attention deficit/hyperactivity syndrome, depression, anxiety disorders and personality disorders are briefly reviewed.

  11. Changes in risk perception over time

    International Nuclear Information System (INIS)

    Gomez, L.S.; Jenkins-Smith, H.C.; Miller, K.W.

    1992-01-01

    The focus of this paper is on changes in perceptions of the risks associated with nuclear waste management over time. In particular, we are interested in the kinds of change that take place when the management programs, and those who are charged with implementing them, are subject to intensive public debate over an extended period of time. We are undertaken an over-time study of perceived risks in Colorado and New Mexico by implementing sequential random household surveys in each state, timed at six month intervals. This study employs three of these surveys, spanning the period from summer, 1990 to summer, 1991. Using these data, we examine the dynamics that may underlie variations in perceived risks over time. In particular, our analysis is focused on changes in the roles played by (1) basic political orientations (i.e. political ideology) and (2) trust in those who advocate conflicting policy positions

  12. Perception, time of perception, perception of the time

    OpenAIRE

    Barata, André

    2009-01-01

    From a conceptual point of view, time is independent of its experience. That is: it can be given a conceptual description of time without any reference to terms related to the subjective consciousness of time. But concerning a phenomenology of that subjective experience of time, it can it be showed that such experience of time is, in itself, temporal. The very same terms employed in a conceptual description of time – terms like “change” and “duration”– are implied in the phenomenological desc...

  13. Sequentially firing neurons confer flexible timing in neural pattern generators

    International Nuclear Information System (INIS)

    Urban, Alexander; Ermentrout, Bard

    2011-01-01

    Neuronal networks exhibit a variety of complex spatiotemporal patterns that include sequential activity, synchrony, and wavelike dynamics. Inhibition is the primary means through which such patterns are implemented. This behavior is dependent on both the intrinsic dynamics of the individual neurons as well as the connectivity patterns. Many neural circuits consist of networks of smaller subcircuits (motifs) that are coupled together to form the larger system. In this paper, we consider a particularly simple motif, comprising purely inhibitory interactions, which generates sequential periodic dynamics. We first describe the dynamics of the single motif both for general balanced coupling (all cells receive the same number and strength of inputs) and then for a specific class of balanced networks: circulant systems. We couple these motifs together to form larger networks. We use the theory of weak coupling to derive phase models which, themselves, have a certain structure and symmetry. We show that this structure endows the coupled system with the ability to produce arbitrary timing relationships between symmetrically coupled motifs and that the phase relationships are robust over a wide range of frequencies. The theory is applicable to many other systems in biology and physics.

  14. Employees’ Perceptions of Corporate Social Responsibility and Job Performance: A Sequential Mediation Model

    Directory of Open Access Journals (Sweden)

    Inyong Shin

    2016-05-01

    Full Text Available In spite of the increasing importance of corporate social responsibility (CSR and employee job performance, little is still known about the links between the socially responsible actions of organizations and the job performance of their members. In order to explain how employees’ perceptions of CSR influence their job performance, this study first examines the relationships between perceived CSR, organizational identification, job satisfaction, and job performance, and then develops a sequential mediation model by fully integrating these links. The results of structural equation modeling analyses conducted for 250 employees at hotels in South Korea offered strong support for the proposed model. We found that perceived CSR was indirectly and positively associated with job performance sequentially mediated first through organizational identification and then job satisfaction. This study theoretically contributes to the CSR literature by revealing the sequential mechanism through which employees’ perceptions of CSR affect their job performance, and offers practical implications by stressing the importance of employees’ perceptions of CSR. Limitations of this study and future research directions are discussed.

  15. Sensory adaptation for timing perception.

    Science.gov (United States)

    Roseboom, Warrick; Linares, Daniel; Nishida, Shin'ya

    2015-04-22

    Recent sensory experience modifies subjective timing perception. For example, when visual events repeatedly lead auditory events, such as when the sound and video tracks of a movie are out of sync, subsequent vision-leads-audio presentations are reported as more simultaneous. This phenomenon could provide insights into the fundamental problem of how timing is represented in the brain, but the underlying mechanisms are poorly understood. Here, we show that the effect of recent experience on timing perception is not just subjective; recent sensory experience also modifies relative timing discrimination. This result indicates that recent sensory history alters the encoding of relative timing in sensory areas, excluding explanations of the subjective phenomenon based only on decision-level changes. The pattern of changes in timing discrimination suggests the existence of two sensory components, similar to those previously reported for visual spatial attributes: a lateral shift in the nonlinear transducer that maps relative timing into perceptual relative timing and an increase in transducer slope around the exposed timing. The existence of these components would suggest that previous explanations of how recent experience may change the sensory encoding of timing, such as changes in sensory latencies or simple implementations of neural population codes, cannot account for the effect of sensory adaptation on timing perception.

  16. "Time sequential high dose of Cytarabine in acute myelocytic leukemia "

    Directory of Open Access Journals (Sweden)

    Ghavamzadeh A

    2003-05-01

    Full Text Available Given preliminary evidence of timed, sequential chemotherapy of high dose cytosine arabinoside the current study was initiated to assess the side effects and efficacy of this regimen in patients with newly acute myelocytic leukemia (AML. Nineteen adults who referred to Hematology-Oncology and Bone Marrow Transplantation (BMT research center of Tehran University of Medical Sciences were enrolled in a trial from Aug 1999 to Nov 2000. All patients had a Karnofski classification above 60%. At this time induction therapy consisted of daunorubicin or idarubicin given at a dose of 60 mg/m² and 12 mg/m² IV respectively on days 1-3, and cytarabine (Ara-C 100 mg/m² intravenously by continuous infusion on days 1-7, followed by Ara-C 1000 mg/m² given on day 8-10 every 12 hours by IV infusion. Consolidation therapy started after 35th day. Of 19 fully evaluable patients, 10 patients achieved a complete remission, whereas 36.6% patients succumbed to death due to regeneration failure. The clinical data show that the overall survival rate from diagnosis 55.5% (95% CI, 30.8-78.5 at 6 months for the entire cohort of the patients. Disease free survival is also 50% (95% CI, 26-74. Mean duration of death due to treatment was 20 days (range 17-29 after beginning the regimen. Presenting WBC counts, French-American-British (FAB classification, sex and age were not useful prognostic variables. Fever, diarrhea, nausea and vomiting and GI hemorrhage were seen in 19, 6, 4, 7 patients respectively. It seems the 3+7+3 regimen is a promising approach for the AML patients regarding to high complete remission rate, but more supportive care should be considered. Furthermore any, benefit in long-term outcome can’t be determined regardless to the choice of post remission therapy (e.g., GCSF, appropriate antibiotics and etc.

  17. Disentangling beat perception from sequential learning and examining the influence of attention and musical abilities on ERP responses to rhythm.

    Science.gov (United States)

    Bouwer, Fleur L; Werner, Carola M; Knetemann, Myrthe; Honing, Henkjan

    2016-05-01

    Beat perception is the ability to perceive temporal regularity in musical rhythm. When a beat is perceived, predictions about upcoming events can be generated. These predictions can influence processing of subsequent rhythmic events. However, statistical learning of the order of sounds in a sequence can also affect processing of rhythmic events and must be differentiated from beat perception. In the current study, using EEG, we examined the effects of attention and musical abilities on beat perception. To ensure we measured beat perception and not absolute perception of temporal intervals, we used alternating loud and soft tones to create a rhythm with two hierarchical metrical levels. To control for sequential learning of the order of the different sounds, we used temporally regular (isochronous) and jittered rhythmic sequences. The order of sounds was identical in both conditions, but only the regular condition allowed for the perception of a beat. Unexpected intensity decrements were introduced on the beat and offbeat. In the regular condition, both beat perception and sequential learning were expected to enhance detection of these deviants on the beat. In the jittered condition, only sequential learning was expected to affect processing of the deviants. ERP responses to deviants were larger on the beat than offbeat in both conditions. Importantly, this difference was larger in the regular condition than in the jittered condition, suggesting that beat perception influenced responses to rhythmic events in addition to sequential learning. The influence of beat perception was present both with and without attention directed at the rhythm. Moreover, beat perception as measured with ERPs correlated with musical abilities, but only when attention was directed at the stimuli. Our study shows that beat perception is possible when attention is not directed at a rhythm. In addition, our results suggest that attention may mediate the influence of musical abilities on beat

  18. Perceptions of Time and Long Time Intervals

    Energy Technology Data Exchange (ETDEWEB)

    Drottz-Sjoeberg, Britt-Marie [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Psychology

    2006-09-15

    There are certainly many perspectives presented in the literature on time and time perception. This contribution has focused on perceptions of the time frames related to risk and danger of radiation from a planned Swedish repository for spent nuclear fuel. Respondents from two municipalities judged SSI's reviews of the entrepreneur's plans and work of high importance, and more important the closer to our time the estimate was given. Similarly were the consequences of potential leakage from a repository perceived as more serious the closer it would be to our time. Judgements of risks related to the storage of spent nuclear fuel were moderately large on the used measurement scales. Experts are experts because they have more knowledge, and in this context they underlined e.g. the importance of reviews of the radiation situation of time periods up to 100,000 years. It was of interest to note that 55% of the respondents from the municipalities did not believe that the future repository would leak radioactivity. They were much more pessimistic with respect to world politics, i.e. a new world war. However, with respect to the seriousness of the consequences given a leakage from the repository, the public group consistently gave high risk estimates, often significantly higher than those of the expert group. The underestimations of time estimates, as seen in the tasks of pinpointing historic events, provide examples of the difficulty of making estimations involving long times. Similar results showed that thinking of 'the future' most often involved about 30 years. On average, people reported memories of about 2.5 generations back in time, and emotional relationships stretching approximately 2.5 generations into the future; 94% of the responses, with respect to how many future generations one had an emotional relationship, were given in the range of 1-5 generations. Similarly, Svenson and Nilsson found the opinion that the current generations

  19. Perceptions of Time and Long Time Intervals

    International Nuclear Information System (INIS)

    Drottz-Sjoeberg, Britt-Marie

    2006-01-01

    There are certainly many perspectives presented in the literature on time and time perception. This contribution has focused on perceptions of the time frames related to risk and danger of radiation from a planned Swedish repository for spent nuclear fuel. Respondents from two municipalities judged SSI's reviews of the entrepreneur's plans and work of high importance, and more important the closer to our time the estimate was given. Similarly were the consequences of potential leakage from a repository perceived as more serious the closer it would be to our time. Judgements of risks related to the storage of spent nuclear fuel were moderately large on the used measurement scales. Experts are experts because they have more knowledge, and in this context they underlined e.g. the importance of reviews of the radiation situation of time periods up to 100,000 years. It was of interest to note that 55% of the respondents from the municipalities did not believe that the future repository would leak radioactivity. They were much more pessimistic with respect to world politics, i.e. a new world war. However, with respect to the seriousness of the consequences given a leakage from the repository, the public group consistently gave high risk estimates, often significantly higher than those of the expert group. The underestimations of time estimates, as seen in the tasks of pinpointing historic events, provide examples of the difficulty of making estimations involving long times. Similar results showed that thinking of 'the future' most often involved about 30 years. On average, people reported memories of about 2.5 generations back in time, and emotional relationships stretching approximately 2.5 generations into the future; 94% of the responses, with respect to how many future generations one had an emotional relationship, were given in the range of 1-5 generations. Similarly, Svenson and Nilsson found the opinion that the current generations' general responsibility for

  20. An accurate approximate solution of optimal sequential age replacement policy for a finite-time horizon

    International Nuclear Information System (INIS)

    Jiang, R.

    2009-01-01

    It is difficult to find the optimal solution of the sequential age replacement policy for a finite-time horizon. This paper presents an accurate approximation to find an approximate optimal solution of the sequential replacement policy. The proposed approximation is computationally simple and suitable for any failure distribution. Their accuracy is illustrated by two examples. Based on the approximate solution, an approximate estimate for the total cost is derived.

  1. Sequential specification of time-aware stream processing applications

    NARCIS (Netherlands)

    Geuns, S.J.; Hausmans, J.P.H.M.; Bekooij, Marco Jan Gerrit

    Automatic parallelization of Nested Loop Programs (NLPs) is an attractive method to create embedded real-time stream processing applications for multi-core systems. However, the description and parallelization of applications with a time dependent functional behavior has not been considered in NLPs.

  2. Unsupervised land cover change detection: meaningful sequential time series analysis

    CSIR Research Space (South Africa)

    Salmon, BP

    2011-06-01

    Full Text Available An automated land cover change detection method is proposed that uses coarse spatial resolution hyper-temporal earth observation satellite time series data. The study compared three different unsupervised clustering approaches that operate on short...

  3. Effects of neostriatal 6-OHDA lesion on performance in a rat sequential reaction time task.

    Science.gov (United States)

    Domenger, D; Schwarting, R K W

    2008-10-31

    Work in humans and monkeys has provided evidence that the basal ganglia, and the neurotransmitter dopamine therein, play an important role for sequential learning and performance. Compared to primates, experimental work in rodents is rather sparse, largely due to the fact that tasks comparable to the human ones, especially serial reaction time tasks (SRTT), had been lacking until recently. We have developed a rat model of the SRTT, which allows to study neural correlates of sequential performance and motor sequence execution. Here, we report the effects of dopaminergic neostriatal lesions, performed using bilateral 6-hydroxydopamine injections, on performance of well-trained rats tested in our SRTT. Sequential behavior was measured in two ways: for one, the effects of small violations of otherwise well trained sequences were examined as a measure of attention and automation. Secondly, sequential versus random performance was compared as a measure of sequential learning. Neurochemically, the lesions led to sub-total dopamine depletions in the neostriatum, which ranged around 60% in the lateral, and around 40% in the medial neostriatum. These lesions led to a general instrumental impairment in terms of reduced speed (response latencies) and response rate, and these deficits were correlated with the degree of striatal dopamine loss. Furthermore, the violation test indicated that the lesion group conducted less automated responses. The comparison of random versus sequential responding showed that the lesion group did not retain its superior sequential performance in terms of speed, whereas they did in terms of accuracy. Also, rats with lesions did not improve further in overall performance as compared to pre-lesion values, whereas controls did. These results support previous results that neostriatal dopamine is involved in instrumental behaviour in general. Also, these lesions are not sufficient to completely abolish sequential performance, at least when acquired

  4. Audio-visual speech perception in prelingually deafened Japanese children following sequential bilateral cochlear implantation.

    Science.gov (United States)

    Yamamoto, Ryosuke; Naito, Yasushi; Tona, Risa; Moroto, Saburo; Tamaya, Rinko; Fujiwara, Keizo; Shinohara, Shogo; Takebayashi, Shinji; Kikuchi, Masahiro; Michida, Tetsuhiko

    2017-11-01

    An effect of audio-visual (AV) integration is observed when the auditory and visual stimuli are incongruent (the McGurk effect). In general, AV integration is helpful especially in subjects wearing hearing aids or cochlear implants (CIs). However, the influence of AV integration on spoken word recognition in individuals with bilateral CIs (Bi-CIs) has not been fully investigated so far. In this study, we investigated AV integration in children with Bi-CIs. The study sample included thirty one prelingually deafened children who underwent sequential bilateral cochlear implantation. We assessed their responses to congruent and incongruent AV stimuli with three CI-listening modes: only the 1st CI, only the 2nd CI, and Bi-CIs. The responses were assessed in the whole group as well as in two sub-groups: a proficient group (syllable intelligibility ≥80% with the 1st CI) and a non-proficient group (syllable intelligibility effect in each of the three CI-listening modes. AV integration responses were observed in a subset of incongruent AV stimuli, and the patterns observed with the 1st CI and with Bi-CIs were similar. In the proficient group, the responses with the 2nd CI were not significantly different from those with the 1st CI whereas in the non-proficient group the responses with the 2nd CI were driven by visual stimuli more than those with the 1st CI. Our results suggested that prelingually deafened Japanese children who underwent sequential bilateral cochlear implantation exhibit AV integration abilities, both in monaural listening as well as in binaural listening. We also observed a higher influence of visual stimuli on speech perception with the 2nd CI in the non-proficient group, suggesting that Bi-CIs listeners with poorer speech recognition rely on visual information more compared to the proficient subjects to compensate for poorer auditory input. Nevertheless, poorer quality auditory input with the 2nd CI did not interfere with AV integration with binaural

  5. Time perception mechanisms at central nervous system

    Directory of Open Access Journals (Sweden)

    Rhailana Fontes

    2016-04-01

    Full Text Available The five senses have specific ways to receive environmental information and lead to central nervous system. The perception of time is the sum of stimuli associated with cognitive processes and environmental changes. Thus, the perception of time requires a complex neural mechanism and may be changed by emotional state, level of attention, memory and diseases. Despite this knowledge, the neural mechanisms of time perception are not yet fully understood. The objective is to relate the mechanisms involved the neurofunctional aspects, theories, executive functions and pathologies that contribute the understanding of temporal perception. Articles form 1980 to 2015 were searched by using the key themes: neuroanatomy, neurophysiology, theories, time cells, memory, schizophrenia, depression, attention-deficit hyperactivity disorder and Parkinson’s disease combined with the term perception of time. We evaluated 158 articles within the inclusion criteria for the purpose of the study. We conclude that research about the holdings of the frontal cortex, parietal, basal ganglia, cerebellum and hippocampus have provided advances in the understanding of the regions related to the perception of time. In neurological and psychiatric disorders, the understanding of time depends on the severity of the diseases and the type of tasks.

  6. Time Perception Mechanisms at Central Nervous System.

    Science.gov (United States)

    Fontes, Rhailana; Ribeiro, Jéssica; Gupta, Daya S; Machado, Dionis; Lopes-Júnior, Fernando; Magalhães, Francisco; Bastos, Victor Hugo; Rocha, Kaline; Marinho, Victor; Lima, Gildário; Velasques, Bruna; Ribeiro, Pedro; Orsini, Marco; Pessoa, Bruno; Leite, Marco Antonio Araujo; Teixeira, Silmar

    2016-04-01

    The five senses have specific ways to receive environmental information and lead to central nervous system. The perception of time is the sum of stimuli associated with cognitive processes and environmental changes. Thus, the perception of time requires a complex neural mechanism and may be changed by emotional state, level of attention, memory and diseases. Despite this knowledge, the neural mechanisms of time perception are not yet fully understood. The objective is to relate the mechanisms involved the neurofunctional aspects, theories, executive functions and pathologies that contribute the understanding of temporal perception. Articles form 1980 to 2015 were searched by using the key themes: neuroanatomy, neurophysiology, theories, time cells, memory, schizophrenia, depression, attention-deficit hyperactivity disorder and Parkinson's disease combined with the term perception of time. We evaluated 158 articles within the inclusion criteria for the purpose of the study. We conclude that research about the holdings of the frontal cortex, parietal, basal ganglia, cerebellum and hippocampus have provided advances in the understanding of the regions related to the perception of time. In neurological and psychiatric disorders, the understanding of time depends on the severity of the diseases and the type of tasks.

  7. Impact of sequential disorder on the scaling behavior of airplane boarding time

    Science.gov (United States)

    Baek, Yongjoo; Ha, Meesoon; Jeong, Hawoong

    2013-05-01

    Airplane boarding process is an example where disorder properties of the system are relevant to the emergence of universality classes. Based on a simple model, we present a systematic analysis of finite-size effects in boarding time, and propose a comprehensive view of the role of sequential disorder in the scaling behavior of boarding time against the plane size. Using numerical simulations and mathematical arguments, we find how the scaling behavior depends on the number of seat columns and the range of sequential disorder. Our results show that new scaling exponents can arise as disorder is localized to varying extents.

  8. Radio controlled detonators and sequential real time blast applications

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, T.; Laboz, J.M. [Delta Caps International, Nice (France)

    1995-12-31

    Among the numerous technical evolutions in the blasting environment the authors are going to describe below the concept of electronic detonator sequenced by radio waves, and also its numerous applications. Three major technologies are used in the initiation environment: fused-initiated detonators; electric detonators; and non-electric detonators. The last two technologies were made available under multiple variants. Two major innovations are going to substantially change the way traditional detonators operate: pyrotechnic delays are replaced by electronic delays (greater accuracy); and triggering orders, passing through a cable, is now replaced by radio-waves transmission (possibility to do real time delay pattern). Such a new product provided all the features offered by current detonators, but also allows mastering specific cases that were difficult to control with the current technology, such as: vibration control; underground blast; and building demolition.

  9. Worker's perceptions of time, time-use-attitudes and productivity

    OpenAIRE

    E. Ben-Baruch; C. P. H. Myburgh; E. C. Anderssen

    1991-01-01

    Decreasing productivity and increasing wage demands are singled out as being crucial problems facing the economy of South Africa. Changes in the time perceptions and time-use-attitudes of workers could play a decisive role in increasing productivity. The relationships between time perception, needs, motivation and productivity are analysed. Culture, tradition, economy, and environment lend a specific significance to these variables. Workers in a technological society should be guided to adapt...

  10. Real-time skin feature identification in a time-sequential video stream

    Science.gov (United States)

    Kramberger, Iztok

    2005-04-01

    Skin color can be an important feature when tracking skin-colored objects. Particularly this is the case for computer-vision-based human-computer interfaces (HCI). Humans have a highly developed feeling of space and, therefore, it is reasonable to support this within intelligent HCI, where the importance of augmented reality can be foreseen. Joining human-like interaction techniques within multimodal HCI could, or will, gain a feature for modern mobile telecommunication devices. On the other hand, real-time processing plays an important role in achieving more natural and physically intuitive ways of human-machine interaction. The main scope of this work is the development of a stereoscopic computer-vision hardware-accelerated framework for real-time skin feature identification in the sense of a single-pass image segmentation process. The hardware-accelerated preprocessing stage is presented with the purpose of color and spatial filtering, where the skin color model within the hue-saturation-value (HSV) color space is given with a polyhedron of threshold values representing the basis of the filter model. An adaptive filter management unit is suggested to achieve better segmentation results. This enables the adoption of filter parameters to the current scene conditions in an adaptive way. Implementation of the suggested hardware structure is given at the level of filed programmable system level integrated circuit (FPSLIC) devices using an embedded microcontroller as their main feature. A stereoscopic clue is achieved using a time-sequential video stream, but this shows no difference for real-time processing requirements in terms of hardware complexity. The experimental results for the hardware-accelerated preprocessing stage are given by efficiency estimation of the presented hardware structure using a simple motion-detection algorithm based on a binary function.

  11. Audience Perceptions of Family Viewing Time

    Science.gov (United States)

    Fontes, Brian F.; And Others

    1977-01-01

    Discusses a survey on Family Viewing Time designed to determine audience reactions to program content including violent and sexual content, audience perceptions of the suitability of program offerings for family viewing, and audience viewing habits with respect to Family Viewing Time. (MH)

  12. The emotional body and time perception.

    Science.gov (United States)

    Droit-Volet, Sylvie; Gil, Sandrine

    2016-01-01

    We examined the effects of emotional bodily expressions on the perception of time. Participants were shown bodily expressions of fear, happiness and sadness in a temporal bisection task featuring different stimulus duration ranges. Stimulus durations were judged to be longer for bodily expressions of fear than for those of sadness, whereas no significant difference was observed between sad and happy postures. In addition, the magnitude of the lengthening effect of fearful versus sad postures increased with duration range. These results suggest that the perception of fearful bodily expressions increases the level of arousal which, in turn, speeds up the internal clock system underlying the representation of time. The effect of bodily expressions on time perception is thus consistent with findings for other highly arousing emotional stimuli, such as emotional facial expressions.

  13. The Neuromagnetic Dynamics of Time Perception

    OpenAIRE

    Carver, Frederick W.; Elvevåg, Brita; Altamura, Mario; Weinberger, Daniel R.; Coppola, Richard

    2012-01-01

    Examining real-time cortical dynamics is crucial for understanding time perception. Using magnetoencephalography we studied auditory duration discrimination of short (.5 s) versus a pitch control. Time-frequency analysis of event-related fields showed widespread beta-band (13-30 Hz) desynchronization during all tone presentations. Synthetic aperture magnetometry indicated automatic primarily sensorimotor responses in short and pitch conditions, with activation specific to timing in bilateral ...

  14. Effect of visual perception training combined with total nutrition meal sequential therapy on myopic amblyopia in preschool children

    Directory of Open Access Journals (Sweden)

    Hong Chen

    2017-12-01

    Full Text Available AIM: To observe the therapeutic effect of visual perception training combined with total nutrition meal sequential therapy in the treatment of myopic amblyopia. METHODS: Totally 73 children(135 eyeswith myopic amblyopia were divided into control group(36 cases, 67 eyesand treatment group(37 cases, 68 eyesaccording to random number table. The control group were treated with traditional spectaculars and grating covering combined with fine eyesight training; the treatment group were treated with visual perception training combined with total nutrient meal sequential therapy. The visual acuity, diopter and average diopter of two groups were compared before and after treatment at 3, 6mo and 1a. The curative effect of two groups of children was compared after 1a treatment. And the adverse reactions were recorded in two groups during the treatment period. The recurrence rate of amblyopia in 1a follow-up was compared between two groups. RESULTS: The difference of visual acuity between two groups was not significant at 3mo(P>0.05. The visual acuity of the treatment group was significantly higher than that of the control group at 6mo and 1a(PP>0.05, but the average annual refractive changes in the treatment group were significantly lower than that in the control group(PPPCONCLUSION: Visual perception training combined with total nutrition meal sequential therapy in the treatment of myopic amblyopia in preschool children can significantly improve patients' visual acuity, reduce the average annual diopter changes, improve the therapeutic effect, reduce the recurrence rate of amblyopia.

  15. On the Relationship between Memory and Perception: Sequential Dependencies in Recognition Memory Testing

    Science.gov (United States)

    Malmberg, Kenneth J.; Annis, Jeffrey

    2012-01-01

    Many models of recognition are derived from models originally applied to perception tasks, which assume that decisions from trial to trial are independent. While the independence assumption is violated for many perception tasks, we present the results of several experiments intended to relate memory and perception by exploring sequential…

  16. The relative timing between eye and hand rapid sequential pointing is affected by time pressure, but not by advance knowledge

    NARCIS (Netherlands)

    Deconinck, F.; van Polanen, V.; Savelsbergh, G.J.P.; Bennett, S.

    2011-01-01

    The present study examined the effect of timing constraints and advance knowledge on eye-hand coordination strategy in a sequential pointing task. Participants were required to point at two successively appearing targets on a screen while the inter-stimulus interval (ISI) and the trial order were

  17. Time perception and time perspective differences between adolescents and adults.

    Science.gov (United States)

    Siu, Nicolson Y F; Lam, Heidi H Y; Le, Jacqueline J Y; Przepiorka, Aneta M

    2014-09-01

    The present experiment aimed to investigate the differences in time perception and time perspective between subjects representing two developmental stages, namely adolescence and middle adulthood. Twenty Chinese adolescents aged 15-25 and twenty Chinese adults aged 35-55 participated in the study. A time discrimination task and a time reproduction task were implemented to measure the accuracy of their time perception. The Zimbardo Time Perspective Inventory (Short-Form) was adopted to assess their time orientation. It was found that adolescents performed better than adults in both the time discrimination task and the time reproduction task. Adolescents were able to differentiate different time intervals with greater accuracy and reproduce the target duration more precisely. For the time reproduction task, it was also found that adults tended to overestimate the duration of the target stimuli while adolescents were more likely to underestimate it. As regards time perspective, adults were more future-oriented than adolescents, whereas adolescents were more present-oriented than adults. No significant relationship was found between time perspective and time perception. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Network structure and travel time perception.

    Science.gov (United States)

    Parthasarathi, Pavithra; Levinson, David; Hochmair, Hartwig

    2013-01-01

    The purpose of this research is to test the systematic variation in the perception of travel time among travelers and relate the variation to the underlying street network structure. Travel survey data from the Twin Cities metropolitan area (which includes the cities of Minneapolis and St. Paul) is used for the analysis. Travelers are classified into two groups based on the ratio of perceived and estimated commute travel time. The measures of network structure are estimated using the street network along the identified commute route. T-test comparisons are conducted to identify statistically significant differences in estimated network measures between the two traveler groups. The combined effect of these estimated network measures on travel time is then analyzed using regression models. The results from the t-test and regression analyses confirm the influence of the underlying network structure on the perception of travel time.

  19. [Time perception in depressed and manic patients].

    Science.gov (United States)

    Zhao, Qi-yuan; Ji, Yi-fu; Wang, Kai; Zhang, Lei; Liu, Ping; Jiang, Yu-bao

    2010-02-02

    To investigate the time perception in affective disorders by using neuropsychological tests and to try to elucidate its neurobiochemical mechanism. Using a time reproduction task, a comparative study was conducted for 28 depressive patients, 22 manic patients, and 26 age and education level matched healthy persons as healthy controls. Both depressive patients and manic patients are abnormal (P reproduction task in patients were not related to age, education, duration of illness, number of admission (P > 0.05), but had some relation to severity of illness.And the results were positively correlated with the score of HAMD in depressive patients (six times: r = 0.44, 0.46, 0.73, 0.61, 0.55, 0.50, P < 0.05), but negatively with the score of BRMS in manic patients (six times: r = -0.57, -0.54, -0.71, -0.69, -0.80, -0.71, P < 0.05). Emotion will affect one's time perception. And the neurotransmitter in brain may participate in the processes of time perception.

  20. Robust real-time pattern matching using bayesian sequential hypothesis testing.

    Science.gov (United States)

    Pele, Ofir; Werman, Michael

    2008-08-01

    This paper describes a method for robust real time pattern matching. We first introduce a family of image distance measures, the "Image Hamming Distance Family". Members of this family are robust to occlusion, small geometrical transforms, light changes and non-rigid deformations. We then present a novel Bayesian framework for sequential hypothesis testing on finite populations. Based on this framework, we design an optimal rejection/acceptance sampling algorithm. This algorithm quickly determines whether two images are similar with respect to a member of the Image Hamming Distance Family. We also present a fast framework that designs a near-optimal sampling algorithm. Extensive experimental results show that the sequential sampling algorithm performance is excellent. Implemented on a Pentium 4 3 GHz processor, detection of a pattern with 2197 pixels, in 640 x 480 pixel frames, where in each frame the pattern rotated and was highly occluded, proceeds at only 0.022 seconds per frame.

  1. The Influence of Odors on Time Perception

    OpenAIRE

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

    2016-01-01

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

  2. The influence of musical training on the perception of sequentially presented mistuned harmonics

    NARCIS (Netherlands)

    Burns, E.M.; Houtsma, A.J.M.

    1999-01-01

    The question of whether musical scales have developed from a processing advantage for frequency ratios based on small integers, i.e., ratios derived from relationships among harmonically related tones, is widely debated in musicology and music perception. In the extreme position, this processing

  3. Insurance-markets Equilibrium with Sequential Non-convex Straight-time and Over-time Labor Supply

    OpenAIRE

    Vasilev, Aleksandar

    2016-01-01

    This note describes the lottery- and insurance-market equilibrium in an economy with non-convex straight-time and overtime employment. In contrast to Hansen and Sargent (1988), the overtime-decision is a sequential one. This requires two separate insurance market to operate, one for straight-time work, and one for overtime. In addi- tion, given that the labor choice for regular and overtime hours is made in succession, the insurance market for overtime needs to open once the insurance market ...

  4. A sequential threshold cure model for genetic analysis of time-to-event data

    DEFF Research Database (Denmark)

    Ødegård, J; Madsen, Per; Labouriau, Rodrigo S.

    2011-01-01

    In analysis of time-to-event data, classical survival models ignore the presence of potential nonsusceptible (cured) individuals, which, if present, will invalidate the inference procedures. Existence of nonsusceptible individuals is particularly relevant under challenge testing with specific...... pathogens, which is a common procedure in aquaculture breeding schemes. A cure model is a survival model accounting for a fraction of nonsusceptible individuals in the population. This study proposes a mixed cure model for time-to-event data, measured as sequential binary records. In a simulation study...... survival data were generated through 2 underlying traits: susceptibility and endurance (risk of dying per time-unit), associated with 2 sets of underlying liabilities. Despite considerable phenotypic confounding, the proposed model was largely able to distinguish the 2 traits. Furthermore, if selection...

  5. Time and time again: risk perceptions by experts, legislators and the public over time

    International Nuclear Information System (INIS)

    Paris, I.; Mays, C.; Sugier, N.

    1998-01-01

    This paper explores the hypothesis that a very different curve in perceptions of managed technological risks may be observed over time in experts, political decision makers, and the general public. Experts may have high risk perceptions during the phase of technology development, with the outcome of risk-reducing design. Members of the public, in their role as consumers, may perceive new technologies as very risky until such time as they have become integrated into everyday practice. At that time, with feedback from experience, risk perceptions may rise again in experts. The perceptions of legislators may respond to those expressed by either or both groups. Economic and social theories of risk perception are cited to construct the curve of risk perception for each group. (authors)

  6. Simulation Study of Real Time 3-D Synthetic Aperture Sequential Beamforming for Ultrasound Imaging

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Rasmussen, Morten Fischer; Stuart, Matthias Bo

    2014-01-01

    in the main system. The real-time imaging capability is achieved using a synthetic aperture beamforming technique, utilizing the transmit events to generate a set of virtual elements that in combination can generate an image. The two core capabilities in combination is named Synthetic Aperture Sequential......This paper presents a new beamforming method for real-time three-dimensional (3-D) ultrasound imaging using a 2-D matrix transducer. To obtain images with sufficient resolution and contrast, several thousand elements are needed. The proposed method reduces the required channel count from...... Beamforming (SASB). Simulations are performed to evaluate the image quality of the presented method in comparison to Parallel beamforming utilizing 16 receive beamformers. As indicators for image quality the detail resolution and Cystic resolution are determined for a set of scatterers at a depth of 90mm...

  7. Ego Depletion in Real-Time: An Examination of the Sequential-Task Paradigm.

    Science.gov (United States)

    Arber, Madeleine M; Ireland, Michael J; Feger, Roy; Marrington, Jessica; Tehan, Joshua; Tehan, Gerald

    2017-01-01

    Current research into self-control that is based on the sequential task methodology is currently at an impasse. The sequential task methodology involves completing a task that is designed to tax self-control resources which in turn has carry-over effects on a second, unrelated task. The current impasse is in large part due to the lack of empirical research that tests explicit assumptions regarding the initial task. Five studies test one key, untested assumption underpinning strength (finite resource) models of self-regulation: Performance will decline over time on a task that depletes self-regulatory resources. In the aftermath of high profile replication failures using a popular letter-crossing task and subsequent criticisms of that task, the current studies examined whether depletion effects would occur in real time using letter-crossing tasks that did not invoke habit-forming and breaking, and whether these effects were moderated by administration type (paper and pencil vs. computer administration). Sample makeup and sizes as well as response formats were also varied across the studies. The five studies yielded a clear and consistent pattern of increasing performance deficits (errors) as a function of time spent on task with generally large effects and in the fifth study the strength of negative transfer effects to a working memory task were related to individual differences in depletion. These results demonstrate that some form of depletion is occurring on letter-crossing tasks though whether an internal regulatory resource reservoir or some other factor is changing across time remains an important question for future research.

  8. Ego Depletion in Real-Time: An Examination of the Sequential-Task Paradigm

    Directory of Open Access Journals (Sweden)

    Madeleine M. Arber

    2017-09-01

    Full Text Available Current research into self-control that is based on the sequential task methodology is currently at an impasse. The sequential task methodology involves completing a task that is designed to tax self-control resources which in turn has carry-over effects on a second, unrelated task. The current impasse is in large part due to the lack of empirical research that tests explicit assumptions regarding the initial task. Five studies test one key, untested assumption underpinning strength (finite resource models of self-regulation: Performance will decline over time on a task that depletes self-regulatory resources. In the aftermath of high profile replication failures using a popular letter-crossing task and subsequent criticisms of that task, the current studies examined whether depletion effects would occur in real time using letter-crossing tasks that did not invoke habit-forming and breaking, and whether these effects were moderated by administration type (paper and pencil vs. computer administration. Sample makeup and sizes as well as response formats were also varied across the studies. The five studies yielded a clear and consistent pattern of increasing performance deficits (errors as a function of time spent on task with generally large effects and in the fifth study the strength of negative transfer effects to a working memory task were related to individual differences in depletion. These results demonstrate that some form of depletion is occurring on letter-crossing tasks though whether an internal regulatory resource reservoir or some other factor is changing across time remains an important question for future research.

  9. Time-Sequential Working Wavelength-Selective Filter for Flat Autostereoscopic Displays

    Directory of Open Access Journals (Sweden)

    René de la Barré

    2017-02-01

    Full Text Available A time-sequential working, spatially-multiplexed autostereoscopic 3D display design consisting of a fast switchable RGB-color filter array and a fast color display is presented. The newly-introduced 3D display design is usable as a multi-user display, as well as a single-user system. The wavelength-selective filter barrier emits the light from a larger aperture than common autostereoscopic barrier displays with similar barrier pitch and ascent. Measurements on a demonstrator with commercial display components, simulations and computational evaluations have been carried out to describe the proposed wavelength-selective display design in static states and to show the weak spots of display filters in commercial displays. An optical modelling of wavelength-selective barriers has been used for instance to calculate the light ray distribution properties of that arrangement. In the time-sequential implementation, it is important to avoid that quick eye or eyelid movement leads to visible color artifacts. Therefore, color filter cells, switching faster than conventional LC display cells, must distribute directed light from different primaries at the same time, to create a 3D presentation. For that, electric tunable liquid crystal Fabry–Pérot color filters are presented. They switch on-off the colors red, green and blue in the millisecond regime. Their active areas consist of a sub-micrometer-thick nematic layer sandwiched between dielectric mirrors and indium tin oxide (ITO-electrodes. These cells shall switch narrowband light of red, green or blue. A barrier filter array for a high resolution, glasses-free 3D display has to be equipped with several thousand switchable filter elements having different color apertures.

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

    Science.gov (United States)

    Moehler, Tobias; Fiehler, Katja

    2015-11-01

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

  11. A sequential model to link contextual risk, perception and public support for flood adaptation policy.

    Science.gov (United States)

    Shao, Wanyun; Xian, Siyuan; Lin, Ning; Small, Mitchell J

    2017-10-01

    The economic damage from coastal flooding has dramatically increased over the past several decades, owing to rapid development in shoreline areas and possible effects of climate change. To respond to these trends, it is imperative for policy makers to understand individuals' support for flood adaptation policy. Using original survey data for all coastal counties of the United States Gulf Coast merged with contextual data on flood risk, this study investigates coastal residents' support for two adaptation policy measures: incentives for relocation and funding for educational programs on emergency planning and evacuation. Specifically, this study explores the interactive relationships among contextual flood risks, perceived flood risks and policy support for flood adaptation, with the effects of social-demographic variables being controlled. Age, gender, race and partisanship are found to significantly affect individuals' policy support for both adaptation measures. The contextual flooding risks, indicated by distance from the coast, maximum wind speed and peak height of storm surge associated with the last hurricane landfall, and percentage of high-risk flood zone per county, are shown to impact one's perceptions of risk, which in turn influence one's support for both policy measures. The key finding -risk perception mediates the impact of contextual risk conditions on public support for flood management policies - highlights the need to ensure that the public is well informed by the latest scientific, engineering and economic knowledge. To achieve this, more information on current and future flood risks and options available for mitigation as well as risk communication tools are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    2008-01-01

    We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the 'extended lead time'. The derived performance measures...

  13. Worker's perceptions of time, time-use-attitudes and productivity

    Directory of Open Access Journals (Sweden)

    E. Ben-Baruch

    1991-06-01

    Full Text Available Decreasing productivity and increasing wage demands are singled out as being crucial problems facing the economy of South Africa. Changes in the time perceptions and time-use-attitudes of workers could play a decisive role in increasing productivity. The relationships between time perception, needs, motivation and productivity are analysed. Culture, tradition, economy, and environment lend a specific significance to these variables. Workers in a technological society should be guided to adapt to and live by the value system needed to uphold productivity. Opsomming Voortdurende afnemende produktiwiteit teenoor looneise wat styg, is een van die kritieke probleme waarmee die Suid-Afrikaanse ekonomie gekonfronteer word. Die verandering van werkers se tydpersepsie en verandering van houdinge teenoor die benutting van tyd kan deurslaggewend in die verhoging van produktiwiteit wees. In die lig hiervan is die verwantskap tussen tydpersepsie, behoeftes, motivering en prodrktiwiteit ondersoek. In die ontleding word aandag geskenk aan die invloed wat kultuur, tradisie, ekonomie en die omgewing op hierdie veranderlikes het. Opieiding in 'n tegnologiese samelewmg behoort daarop gerig te wees om 'n waardesisteem by werkers te laat ontwikkel wat produktiwiteit kan bevorder.

  14. [Dynamic Attending Binds Time and Rhythm Perception].

    Science.gov (United States)

    Kuroda, Tsuyoshi; Ono, Fuminori; Kadota, Hiroshi

    2017-11-01

    Relations between time and rhythm perception are discussed in this review of psychophysical research relevant to the multiple-look effect and dynamic-attending theory. Discrimination of two neighboring intervals that are marked by three successive sounds is improved when the presentation of the first (standard, S) interval is repeated before that of the second (comparison, C), as SSSSC. This improvement in sensitivity, called the multiple-look effect, occurs because listeners (1) perceive regular rhythm during the repetition of the standard interval, (2) predict the timing of subsequent sounds, and (3) detect sounds that are deviated from the predicted timing. The dynamic-attending theory attributes such predictions to the entrainment of attentional rhythms. An endogenous attentional rhythm is synchronized with the periodic succession of sounds marking the repeated standard. The standard and the comparison are discriminated on the basis of whether the ending marker of the comparison appears at the peak of the entrained attentional rhythm. This theory is compatible with the findings of recent neurophysiological studies that relate temporal prediction to neural oscillations.

  15. Note: Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    We show that well-known textbook formulae for determining the optimal base stock of the inventory system with continuous review and constant lead time can easily be extended to the case with periodic review and stochastic, sequential lead times. The provided performance measures and conditions...

  16. Perception is more than time delays

    NARCIS (Netherlands)

    Pala, O.; Rouwette, E.A.J.A.

    2013-01-01

    In this paper, we look at the way perceptions – a vital component of any decision-making process – are modeled in System Dynamics (SD) models. SD models include perceptions as a factor translating actual into observed conditions. System dynamicists assume that true conditions are not available to

  17. Patient specific dynamic geometric models from sequential volumetric time series image data.

    Science.gov (United States)

    Cameron, B M; Robb, R A

    2004-01-01

    Generating patient specific dynamic models is complicated by the complexity of the motion intrinsic and extrinsic to the anatomic structures being modeled. Using a physics-based sequentially deforming algorithm, an anatomically accurate dynamic four-dimensional model can be created from a sequence of 3-D volumetric time series data sets. While such algorithms may accurately track the cyclic non-linear motion of the heart, they generally fail to accurately track extrinsic structural and non-cyclic motion. To accurately model these motions, we have modified a physics-based deformation algorithm to use a meta-surface defining the temporal and spatial maxima of the anatomic structure as the base reference surface. A mass-spring physics-based deformable model, which can expand or shrink with the local intrinsic motion, is applied to the metasurface, deforming this base reference surface to the volumetric data at each time point. As the meta-surface encompasses the temporal maxima of the structure, any extrinsic motion is inherently encoded into the base reference surface and allows the computation of the time point surfaces to be performed in parallel. The resultant 4-D model can be interactively transformed and viewed from different angles, showing the spatial and temporal motion of the anatomic structure. Using texture maps and per-vertex coloring, additional data such as physiological and/or biomechanical variables (e.g., mapping electrical activation sequences onto contracting myocardial surfaces) can be associated with the dynamic model, producing a 5-D model. For acquisition systems that may capture only limited time series data (e.g., only images at end-diastole/end-systole or inhalation/exhalation), this algorithm can provide useful interpolated surfaces between the time points. Such models help minimize the number of time points required to usefully depict the motion of anatomic structures for quantitative assessment of regional dynamics.

  18. Time perception, pacing and exercise intensity: maximal exercise distorts the perception of time

    OpenAIRE

    Edwards, A. M.; McCormick, A.

    2017-01-01

    Introduction\\ud \\ud Currently there are no data examining the impact of exercise on the perception of time, which is surprising as optimal competitive performance is dependent on accurate pacing using knowledge of time elapsed.\\ud \\ud \\ud Methods\\ud \\ud With institutional ethics approval, 12 recreationally active adult participants (f = 7, m = 5) undertook both 30 s Wingate cycles and 20 min (1200 s) rowing ergometer bouts as short and long duration self-paced exercise trials, in each of thre...

  19. Time sequential single photon emission computed tomography studies in brain tumour using thallium-201

    International Nuclear Information System (INIS)

    Ueda, Takashi; Kaji, Yasuhiro; Wakisaka, Shinichiro; Watanabe, Katsushi; Hoshi, Hiroaki; Jinnouchi, Seishi; Futami, Shigemi

    1993-01-01

    Time sequential single photon emission computed tomography (SPECT) studies using thallium-201 were performed in 25 patients with brain tumours to evaluate the kinetics of thallium in the tumour and the biological malignancy grade preoperatively. After acquisition and reconstruction of SPECT data from 1 min post injection to 48 h (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 15-20 min, followed by 4-6, 24 and 48 h), the thallium uptake ratio in the tumour versus the homologous contralateral area of the brain was calculated and compared with findings of X-ray CT, magnetic resonance imaging, cerebral angiography and histological investigations. Early uptake of thallium in tumours was related to tumour vascularity and the disruption of the blood-brain barrier. High and rapid uptake and slow reduction of thallium indicated a hypervascular malignant tumour; however, high and rapid uptake but rapid reduction of thallium indicated a hypervascular benign tumour, such as meningioma. Hypovascular and benign tumours tended to show low uptake and slow reduction of thallium. Long-lasting retention or uptake of thallium indicates tumour malignancy. (orig.)

  20. Time perception: the bad news and the good

    Science.gov (United States)

    Matthews, William J; Meck, Warren H

    2014-01-01

    Time perception is fundamental and heavily researched, but the field faces a number of obstacles to theoretical progress. In this advanced review, we focus on three pieces of ‘bad news’ for time perception research: temporal perception is highly labile across changes in experimental context and task; there are pronounced individual differences not just in overall performance but in the use of different timing strategies and the effect of key variables; and laboratory studies typically bear little relation to timing in the ‘real world’. We describe recent examples of these issues and in each case offer some ‘good news’ by showing how new research is addressing these challenges to provide rich insights into the neural and information-processing bases of timing and time perception. PMID:25210578

  1. On the Cyclotomic Quantum Algebra of Time Perception

    OpenAIRE

    Planat, Michel

    2004-01-01

    I develop the idea that time perception is the quantum counterpart to time measurement. Phase-locking and prime number theory were proposed as the unifying concepts for understanding the optimal synchronization of clocks and their 1/f frequency noise. Time perception is shown to depend on the thermodynamics of a quantum algebra of number and phase operators already proposed for quantum computational tasks, and to evolve according to a Hamiltonian mimicking Fechner's law. The mathematics is Bo...

  2. Inhomogeneities detection in annual precipitation time series in Portugal using direct sequential simulation

    Science.gov (United States)

    Caineta, Júlio; Ribeiro, Sara; Costa, Ana Cristina; Henriques, Roberto; Soares, Amílcar

    2014-05-01

    Climate data homogenisation is of major importance in monitoring climate change, the validation of weather forecasting, general circulation and regional atmospheric models, modelling of erosion, drought monitoring, among other studies of hydrological and environmental impacts. This happens because non-climate factors can cause time series discontinuities which may hide the true climatic signal and patterns, thus potentially bias the conclusions of those studies. In the last two decades, many methods have been developed to identify and remove these inhomogeneities. One of those is based on geostatistical simulation (DSS - direct sequential simulation), where local probability density functions (pdf) are calculated at candidate monitoring stations, using spatial and temporal neighbouring observations, and then are used for detection of inhomogeneities. This approach has been previously applied to detect inhomogeneities in four precipitation series (wet day count) from a network with 66 monitoring stations located in the southern region of Portugal (1980-2001). This study revealed promising results and the potential advantages of geostatistical techniques for inhomogeneities detection in climate time series. This work extends the case study presented before and investigates the application of the geostatistical stochastic approach to ten precipitation series that were previously classified as inhomogeneous by one of six absolute homogeneity tests (Mann-Kendall test, Wald-Wolfowitz runs test, Von Neumann ratio test, Standard normal homogeneity test (SNHT) for a single break, Pettit test, and Buishand range test). Moreover, a sensibility analysis is implemented to investigate the number of simulated realisations that should be used to accurately infer the local pdfs. Accordingly, the number of simulations per iteration is increased from 50 to 500, which resulted in a more representative local pdf. A set of default and recommended settings is provided, which will help

  3. Perceptions and experiences of a gender gap at a Canadian research institute and potential strategies to mitigate this gap: a sequential mixed-methods study.

    Science.gov (United States)

    Mascarenhas, Alekhya; Moore, Julia E; Tricco, Andrea C; Hamid, Jemila; Daly, Caitlin; Bain, Julie; Jassemi, Sabrina; Kiran, Tara; Baxter, Nancy; Straus, Sharon E

    2017-01-01

    The gender gap in academia is long-standing. Failure to ensure that our academic faculty reflect our student pool and national population deprives Canada of talent. We explored the gender distribution and perceptions of the gender gap at a Canadian university-affiliated, hospital-based research institute. We completed a sequential mixed-methods study. In phase 1, we used the research institute's registry of scientists (1999-2014) and estimated overall prevalence of a gender gap and the gap with respect to job description (e.g., associate v. full-time) and research discipline. In phase 2, we conducted qualitative interviews to provide context for phase 1 data. Both purposive and snowball sampling were used for recruitment. The institute included 30.1% ( n = 62) women and 69.9% ( n = 144) men, indicating a 39.8% gender gap. Most full-time scientists (60.3%, n = 70) were clinicians; there were 54.2% more male than female clinician scientists. Ninety-five percent of basic scientists were men, indicating a 90.5% gap. Seven key themes emerged from 21 interviews, including perceived impact of the gender gap, factors perceived to influence the gap, recruitment trends, presence of institutional support, mentorship and suggestions to mitigate the gap. Several factors were postulated to contribute to the gender gap, including unconscious bias in hiring. A substantial gender gap exists within this research institute. Participants identified strategies to address this gap, such as establishing transparent search processes, providing opportunities for informal networking and mentorship of female scientists and establishing institutional support for work-life balance.

  4. Timed sequential chemotherapy of cytoxan-refractory multiple myeloma with cytoxan and adriamycin based on induced tumor proliferation.

    Science.gov (United States)

    Karp, J E; Humphrey, R L; Burke, P J

    1981-03-01

    Malignant plasma cell proliferation and induced humoral stimulatory activity (HSA) occur in vivo at a predictable time following drug administration. Sequential sera from 11 patients with poor-risk multiple myeloma (MM) undergoing treatment with Cytoxan (CY) 2400 mq/sq m were assayed for their in vitro effects on malignant bone marrow plasma cell tritiated thymidine (3HTdR) incorporation. Peak HSA was detected day 9 following CY. Sequential changes in marrow malignant plasma cell 3HTdR-labeling indices (LI) paralleled changes in serum activity, with peak LI occurring at the time of peak HS. An in vitro model of chemotherapy demonstrated that malignant plasma cell proliferation was enhanced by HSA, as determined by 3HTdR incorporation assay, 3HTdR LI, and tumor cells counts, and that stimulated plasma cells were more sensitive to cytotoxic effects of adriamycin (ADR) than were cells cultured in autologous pretreatment serum. Based on these studies, we designed a clinical trial to treat 12 CY-refractory poor-risk patients with MM in which ADR (60 mg/sq m) was administered at the time of peak HSA and residual tumor cell LI (day 9) following initial CY, 2400 mg/m (CY1ADR9). Eight of 12 (67%) responded to timed sequential chemotherapy with a greater than 50% decrement in monoclonal protein marker and a median survival projected to be greater than 8 mo duration (range 4-21+ mo). These clinical results using timed sequential CY1ADR9 compare favorably with results obtained using ADR in nonsequential chemotherapeutic regimens.

  5. Neural Networks for Time Perception and Working Memory

    Science.gov (United States)

    Üstün, Sertaç; Kale, Emre H.; Çiçek, Metehan

    2017-01-01

    Time is an important concept which determines most human behaviors, however questions remain about how time is perceived and which areas of the brain are responsible for time perception. The aim of this study was to evaluate the relationship between time perception and working memory in healthy adults. Functional magnetic resonance imaging (fMRI) was used during the application of a visual paradigm. In all of the conditions, the participants were presented with a moving black rectangle on a gray screen. The rectangle was obstructed by a black bar for a time period and then reappeared again. During different conditions, participants (n = 15, eight male) responded according to the instructions they were given, including details about time and the working memory or dual task requirements. The results showed activations in right dorsolateral prefrontal and right intraparietal cortical networks, together with the anterior cingulate cortex (ACC), anterior insula and basal ganglia (BG) during time perception. On the other hand, working memory engaged the left prefrontal cortex, ACC, left superior parietal cortex, BG and cerebellum activity. Both time perception and working memory were related to a strong peristriate cortical activity. On the other hand, the interaction of time and memory showed activity in the intraparietal sulcus (IPS) and posterior cingulate cortex (PCC). These results support a distributed neural network based model for time perception and that the intraparietal and posterior cingulate areas might play a role in the interface of memory and timing. PMID:28286475

  6. A Robust Real Time Direction-of-Arrival Estimation Method for Sequential Movement Events of Vehicles.

    Science.gov (United States)

    Liu, Huawei; Li, Baoqing; Yuan, Xiaobing; Zhou, Qianwei; Huang, Jingchang

    2018-03-27

    Parameters estimation of sequential movement events of vehicles is facing the challenges of noise interferences and the demands of portable implementation. In this paper, we propose a robust direction-of-arrival (DOA) estimation method for the sequential movement events of vehicles based on a small Micro-Electro-Mechanical System (MEMS) microphone array system. Inspired by the incoherent signal-subspace method (ISM), the method that is proposed in this work employs multiple sub-bands, which are selected from the wideband signals with high magnitude-squared coherence to track moving vehicles in the presence of wind noise. The field test results demonstrate that the proposed method has a better performance in emulating the DOA of a moving vehicle even in the case of severe wind interference than the narrowband multiple signal classification (MUSIC) method, the sub-band DOA estimation method, and the classical two-sided correlation transformation (TCT) method.

  7. Dedicated workspaces: Faster resumption times and reduced cognitive load in sequential multitasking

    DEFF Research Database (Denmark)

    Jeuris, Steven; Bardram, Jakob Eyvind

    2016-01-01

    Studies show that virtual desktops have become a widespread approach to window management within desktop environments. However, despite their success, there is no experimental evidence of their effect on multitasking. In this paper, we present an experimental study incorporating 16 participants...... to perform the same tasks. Results show that adopting virtual desktops as dedicated workspaces allows for faster task resumption (10 s faster on average) and reduced cognitive load during sequential multitasking. Within our experiment the majority of users already benefited from using dedicated workspaces...

  8. Motor timing deficits in sequential movements in Parkinson disease are related to action planning: a motor imagery study.

    Directory of Open Access Journals (Sweden)

    Laura Avanzino

    Full Text Available Timing of sequential movements is altered in Parkinson disease (PD. Whether timing deficits in internally generated sequential movements in PD depends also on difficulties in motor planning, rather than merely on a defective ability to materially perform the planned movement is still undefined. To unveil this issue, we adopted a modified version of an established test for motor timing, i.e. the synchronization-continuation paradigm, by introducing a motor imagery task. Motor imagery is thought to involve mainly processes of movement preparation, with reduced involvement of end-stage movement execution-related processes. Fourteen patients with PD and twelve matched healthy volunteers were asked to tap in synchrony with a metronome cue (SYNC and then, when the tone stopped, to keep tapping, trying to maintain the same rhythm (CONT-EXE or to imagine tapping at the same rhythm, rather than actually performing it (CONT-MI. We tested both a sub-second and a supra-second inter-stimulus interval between the cues. Performance was recorded using a sensor-engineered glove and analyzed measuring the temporal error and the interval reproduction accuracy index. PD patients were less accurate than healthy subjects in the supra-second time reproduction task when performing both continuation tasks (CONT-MI and CONT-EXE, whereas no difference was detected in the synchronization task and on all tasks involving a sub-second interval. Our findings suggest that PD patients exhibit a selective deficit in motor timing for sequential movements that are separated by a supra-second interval and that this deficit may be explained by a defect of motor planning. Further, we propose that difficulties in motor planning are of a sufficient degree of severity in PD to affect also the motor performance in the supra-second time reproduction task.

  9. Time Slices: What Is the Duration of a Percept?

    Directory of Open Access Journals (Sweden)

    Michael H Herzog

    2016-04-01

    Full Text Available We experience the world as a seamless stream of percepts. However, intriguing illusions and recent experiments suggest that the world is not continuously translated into conscious perception. Instead, perception seems to operate in a discrete manner, just like movies appear continuous although they consist of discrete images. To explain how the temporal resolution of human vision can be fast compared to sluggish conscious perception, we propose a novel conceptual framework in which features of objects, such as their color, are quasi-continuously and unconsciously analyzed with high temporal resolution. Like other features, temporal features, such as duration, are coded as quantitative labels. When unconscious processing is "completed," all features are simultaneously rendered conscious at discrete moments in time, sometimes even hundreds of milliseconds after stimuli were presented.

  10. Employee perceptions of managers' leadership over time.

    Science.gov (United States)

    Palm, Kristina; Ullström, Susanne; Sandahl, Christer; Bergman, David

    2015-01-01

    This paper aims to explore if and how employees in a healthcare organisation perceive changes in their managers' leadership behaviour over time. An interview study was conducted with employees whose managers had participated in a two-year leadership development programme offered by their employer, Healthcare Provision Stockholm County. Qualitative content analysis was applied, and the interview discussions focused on areas in which the majority of the informants perceived that a change had occurred over time and their answers were relatively consistent. The majority of employees did discern changes in their managers' leadership over time, and, with very few exceptions, these changes were described as improvements. The knowledge that employees perceived changes in their managers' leadership supports investments in leadership development through courses, programmes or other initiatives. The present findings contribute to a deeper empirical understanding of leadership as it is practised over time in everyday contexts among employees in healthcare organisations.

  11. Career Expectations and Perceptions of Part-Time MBA Students

    Science.gov (United States)

    Fish, Lynn A.; Fish, Lauren A.

    2010-01-01

    In the U.S., part-time MBA students regard work/life balance as the critical factor that drives career expectations and perceptions. Job aspects and benefits/compensation closely follow in importance, while employee relations are valued less. Within work/life balance, students value job location, travel time, and telecommuting. Promotional…

  12. Retrospective time perception in Korsakoff's syndrome

    NARCIS (Netherlands)

    El Haj, M.; Nandrino, J.L.; Kessels, R.P.C.; Matton, C.; Bacquet, J.E.; Urso, L.; Antoine, P.

    2017-01-01

    The authors investigated retrospective timing in participants with Korsakoff's syndrome. Patients were assessed on four retrospective tasks on which they were instructed to read three-digit numbers aloud (15 seconds), fill connected squares (30 seconds), decide whether words were abstract or

  13. Temporal cognition: Connecting subjective time to perception, attention, and memory.

    Science.gov (United States)

    Matthews, William J; Meck, Warren H

    2016-08-01

    Time is a universal psychological dimension, but time perception has often been studied and discussed in relative isolation. Increasingly, researchers are searching for unifying principles and integrated models that link time perception to other domains. In this review, we survey the links between temporal cognition and other psychological processes. Specifically, we describe how subjective duration is affected by nontemporal stimulus properties (perception), the allocation of processing resources (attention), and past experience with the stimulus (memory). We show that many of these connections instantiate a "processing principle," according to which perceived time is positively related to perceptual vividity and the ease of extracting information from the stimulus. This empirical generalization generates testable predictions and provides a starting-point for integrated theoretical frameworks. By outlining some of the links between temporal cognition and other domains, and by providing a unifying principle for understanding these effects, we hope to encourage time-perception researchers to situate their work within broader theoretical frameworks, and that researchers from other fields will be inspired to apply their insights, techniques, and theorizing to improve our understanding of the representation and judgment of time. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. Odors bias time perception in visual and auditory modalities

    Directory of Open Access Journals (Sweden)

    Zhenzhu eYue

    2016-04-01

    Full Text Available Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 ms or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor. The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a

  15. Odors Bias Time Perception in Visual and Auditory Modalities.

    Science.gov (United States)

    Yue, Zhenzhu; Gao, Tianyu; Chen, Lihan; Wu, Jiashuang

    2016-01-01

    Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal) were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor). The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a framework of

  16. Early lymphocyte recovery after intensive timed sequential chemotherapy for acute myelogenous leukemia: peripheral oligoclonal expansion of regulatory T cells.

    Science.gov (United States)

    Kanakry, Christopher G; Hess, Allan D; Gocke, Christopher D; Thoburn, Christopher; Kos, Ferdynand; Meyer, Christian; Briel, Janet; Luznik, Leo; Smith, B Douglas; Levitsky, Hyam; Karp, Judith E

    2011-01-13

    Few published studies characterize early lymphocyte recovery after intensive chemotherapy for acute myelogenous leukemia (AML). To test the hypothesis that lymphocyte recovery mirrors ontogeny, we characterized early lymphocyte recovery in 20 consecutive patients undergoing induction timed sequential chemotherapy for newly diagnosed AML. Recovering T lymphocytes were predominantly CD4(+) and included a greatly expanded population of CD3(+)CD4(+)CD25(+)Foxp3(+) T cells. Recovering CD3(+)CD4(+)CD25(+)Foxp3(+) T cells were phenotypically activated regulatory T cells and showed suppressive activity on cytokine production in a mixed lymphocyte reaction. Despite an initial burst of thymopoiesis, most recovering regulatory T cells were peripherally derived. Furthermore, regulatory T cells showed marked oligoclonal skewing, suggesting that their peripheral expansion was antigen-driven. Overall, lymphocyte recovery after chemotherapy differs from ontogeny, specifically identifying a peripherally expanded oligoclonal population of activated regulatory T lymphocytes. These differences suggest a stereotyped immunologic recovery shared by patients with newly diagnosed AML after induction timed sequential chemotherapy. Further insight into this oligoclonal regulatory T-cell population will be fundamental toward developing effective immunomodulatory techniques to improve survival for patients with AML.

  17. A meta-analysis of response-time tests of the sequential two-systems model of moral judgment.

    Science.gov (United States)

    Baron, Jonathan; Gürçay, Burcu

    2017-05-01

    The (generalized) sequential two-system ("default interventionist") model of utilitarian moral judgment predicts that utilitarian responses often arise from a system-two correction of system-one deontological intuitions. Response-time (RT) results that seem to support this model are usually explained by the fact that low-probability responses have longer RTs. Following earlier results, we predicted response probability from each subject's tendency to make utilitarian responses (A, "Ability") and each dilemma's tendency to elicit deontological responses (D, "Difficulty"), estimated from a Rasch model. At the point where A = D, the two responses are equally likely, so probability effects cannot account for any RT differences between them. The sequential two-system model still predicts that many of the utilitarian responses made at this point will result from system-two corrections of system-one intuitions, hence should take longer. However, when A = D, RT for the two responses was the same, contradicting the sequential model. Here we report a meta-analysis of 26 data sets, which replicated the earlier results of no RT difference overall at the point where A = D. The data sets used three different kinds of moral judgment items, and the RT equality at the point where A = D held for all three. In addition, we found that RT increased with A-D. This result holds for subjects (characterized by Ability) but not for items (characterized by Difficulty). We explain the main features of this unanticipated effect, and of the main results, with a drift-diffusion model.

  18. A Sequential, Implicit, Wavelet-Based Solver for Multi-Scale Time-Dependent Partial Differential Equations

    Directory of Open Access Journals (Sweden)

    Donald A. McLaren

    2013-04-01

    Full Text Available This paper describes and tests a wavelet-based implicit numerical method for solving partial differential equations. Intended for problems with localized small-scale interactions, the method exploits the form of the wavelet decomposition to divide the implicit system created by the time-discretization into multiple smaller systems that can be solved sequentially. Included is a test on a basic non-linear problem, with both the results of the test, and the time required to calculate them, compared with control results based on a single system with fine resolution. The method is then tested on a non-trivial problem, its computational time and accuracy checked against control results. In both tests, it was found that the method requires less computational expense than the control. Furthermore, the method showed convergence towards the fine resolution control results.

  19. Perception of short time scale intervals in a hypnotic virtuoso

    NARCIS (Netherlands)

    Noreika, Valdas; Falter, Christine M.; Arstila, Valtteri; Wearden, John H.; Kallio, Sakari

    2012-01-01

    Previous studies showed that hypnotized individuals underestimate temporal intervals in the range of several seconds to tens of minutes. However, no previous work has investigated whether duration perception is equally disorderly when shorter time intervals are probed. In this study, duration

  20. A diagnostic tool on time perception of children with ADHD

    NARCIS (Netherlands)

    Gongsook, P.; Peijnenborgh, J.; Sallustro, C.; Spek, van der E.D.; Hu, J.; Bellotti, F.; Rauterberg, G.W.M.; Hendriksen, J.G.M.; De Gloria, A.

    2014-01-01

    ADHD is among the most common childhood developmental disorder which may affect the school achievements. Children with ADHD may show symptoms of time perception problems. Although ADHD is a clinical diagnosis with several approaches, no diagnostic tool has been designed to detect the symptoms of

  1. Changes of peritoneal transport parameters with time on dialysis: assessment with sequential peritoneal equilibration test.

    Science.gov (United States)

    Waniewski, Jacek; Antosiewicz, Stefan; Baczynski, Daniel; Poleszczuk, Jan; Pietribiasi, Mauro; Lindholm, Bengt; Wankowicz, Zofia

    2017-10-27

    Sequential peritoneal equilibration test (sPET) is based on the consecutive performance of the peritoneal equilibration test (PET, 4-hour, glucose 2.27%) and the mini-PET (1-hour, glucose 3.86%), and the estimation of peritoneal transport parameters with the 2-pore model. It enables the assessment of the functional transport barrier for fluid and small solutes. The objective of this study was to check whether the estimated model parameters can serve as better and earlier indicators of the changes in the peritoneal transport characteristics than directly measured transport indices that depend on several transport processes. 17 patients were examined using sPET twice with the interval of about 8 months (230 ± 60 days). There was no difference between the observational parameters measured in the 2 examinations. The indices for solute transport, but not net UF, were well correlated between the examinations. Among the estimated parameters, a significant decrease between the 2 examinations was found only for hydraulic permeability LpS, and osmotic conductance for glucose, whereas the other parameters remained unchanged. These fluid transport parameters did not correlate with D/P for creatinine, although the decrease in LpS values between the examinations was observed mostly for patients with low D/P for creatinine. We conclude that changes in fluid transport parameters, hydraulic permeability and osmotic conductance for glucose, as assessed by the pore model, may precede the changes in small solute transport. The systematic assessment of fluid transport status needs specific clinical and mathematical tools beside the standard PET tests.

  2. Activation time and material stiffness of sequential removable orthodontic appliances. Part 2: Dental improvements.

    Science.gov (United States)

    Clements, Karen Michelle; Bollen, Anne-Marie; Huang, Greg; King, Greg; Hujoel, Philippe; Ma, Tsun

    2003-11-01

    Fifty-one patients were enrolled in this study to explore the treatment effects of material stiffness and frequency of appliance change when using clear, sequential, removable appliances (aligners). Patients were stratified based on pretreatment peer assessment rating (PAR) scores and need for extractions. They were randomized into 4 treatment protocols: 1-week activation with soft material, 1-week activation with hard material, 2-week activation with soft material, and 2-week activation with hard material. Patients continued with their protocols until either the series of aligners was completed, or until it was determined that the aligner was not fitting well (study end point). Weighted PAR score and average incisor irregularity (AII) indexes were used to measure pretreatment and end-point study models, and average improvement was compared among the 4 groups. In addition to the evaluation of the 4 treatment groups, comparisons were made of the individual components of the PAR score to determine which occlusal components experienced the most correction with the aligners. The percentages and absolute extraction space closures were evaluated, and papillary bleeding scores before and during treatment were compared. Although no statistical difference was observed between the 4 treatment groups, a trend was noted with the 2-week frequency having a larger percentage of reduction in weighted PAR and AII scores, and greater extraction space closure. Anterior alignment was the most improved component, and buccal occlusion was the least improved. When analyzed by type of extraction, incisor extraction sites had a significantly greater percentage of closure than either maxillary or mandibular premolar extraction sites. A statistically significant decrease in mean average papillary bleeding score was found during treatment when compared with pretreatment scores, although this difference was not clinically significant.

  3. Disentangling beat perception from sequential learning and examining the influence of attention and musical abilities on ERP responses to rhythm

    NARCIS (Netherlands)

    Bouwer, F.L.; Werner, C.M.; Knetemann, M.; Honing, H.

    Beat perception is the ability to perceive temporal regularity in musical rhythm. When a beat is perceived, predictions about upcoming events can be generated. These predictions can influence processing of subsequent rhythmic events. However, statistical learning of the order of sounds in a sequence

  4. Psychological Perception of Space and Time in the Historical Process

    Directory of Open Access Journals (Sweden)

    Konstantin V. Minyar-Beloruchev

    2015-06-01

    Full Text Available The paper is devoted to psychological aspects and psychological perception of spatial and temporal dimensions of the historical process. Space and time do not exist separately, they are closely interconnected: everything that happens in history has certain spatial and temporal position. From historical perspective spatial characteristics of a particular territory are twofold: territory’s psychical position remains unperturbed, while its political status and national affiliation are revised in the course of time. Territories vary in their value: the most valuable objects of physical environment such as sea-coasts, courses and estuaries of rivers, mineral deposits, industrial regions, etc. serve as objects of contention on the international arena, while areas that do not possess such characteristics can be of no interest to international actors. Historical time does not necessarily coincide with chronological time. For example, according to Eric Hobsbawm, the so-called long Nineteenth Century lasted from 1789 to 1914, while the short Twentieth Century lasted only from 1914 to 1991. Psychological time should also be taken into account – perception of relation between past, present, and future developments, as well as perception of chronological intervals within which certain historical developments take place. Time sets chronological framework for the historical process, it can be both cyclical and linear at the same time. Progress in transportation and communication leads to the situation where linear characteristics of space and time remain the same, while space compresses and time accelerates: movement of physical objects and information transfer take less and less time. Such process was ushered in during the Nineteenth Century (Transportation and Communication Revolutions and it accelerated in the Twentieth and Twenty-First Centuries. Present wars can last only months and days, not years; negotiations are conducted directly by chief

  5. Time-sequential observation of spindle and phragmoplast orientation in BY-2 cells with altered cortical actin microfilament patterning.

    Science.gov (United States)

    Kojo, Kei H; Yasuhara, Hiroki; Hasezawa, Seiichiro

    2014-01-01

    Precise division plane determination is essential for plant development. At metaphase, a dense actin microfilament meshwork appears on both sides of the cell center, forming a characteristic cortical actin microfilament twin peak pattern in BY-2 cells. We previously reported a strong correlation between altered cortical actin microfilament patterning and an oblique mitotic spindle orientation, implying that these actin microfilament twin peaks play a role in the regulation of mitotic spindle orientation. In the present study, time-sequential observation was used to reveal the progression from oblique phragmoplast to oblique cell plate orientation in cells with altered cortical actin microfilament patterning. In contrast to cells with normal actin microfilament twin peaks, oblique phragmoplast reorientation was rarely observed in cells with altered cortical actin microfilament patterning. These results support the important roles of cortical actin microfilament patterning in division plane orientation.

  6. Sequential Specification of Time-aware Stream Processing Applications (Extended Abstract)

    NARCIS (Netherlands)

    Geuns, S.J.; Hausmans, J.P.H.M.; Bekooij, Marco Jan Gerrit

    2012-01-01

    Automatic parallelization of Nested Loop Programs (NLPs) is an attractive method to create embedded real-time stream processing applications for multi-core systems. However, the description and parallelization of applications with a time dependent functional behavior has not been considered in NLPs.

  7. Time optimization of 90Sr measurements: Sequential measurement of multiple samples during ingrowth of 90Y

    International Nuclear Information System (INIS)

    Holmgren, Stina; Tovedal, Annika; Björnham, Oscar; Ramebäck, Henrik

    2016-01-01

    The aim of this paper is to contribute to a more rapid determination of a series of samples containing 90 Sr by making the Cherenkov measurement of the daughter nuclide 90 Y more time efficient. There are many instances when an optimization of the measurement method might be favorable, such as; situations requiring rapid results in order to make urgent decisions or, on the other hand, to maximize the throughput of samples in a limited available time span. In order to minimize the total analysis time, a mathematical model was developed which calculates the time of ingrowth as well as individual measurement times for n samples in a series. This work is focused on the measurement of 90 Y during ingrowth, after an initial chemical separation of strontium, in which it is assumed that no other radioactive strontium isotopes are present. By using a fixed minimum detectable activity (MDA) and iterating the measurement time for each consecutive sample the total analysis time will be less, compared to using the same measurement time for all samples. It was found that by optimization, the total analysis time for 10 samples can be decreased greatly, from 21 h to 6.5 h, when assuming a MDA of 1 Bq/L and at a background count rate of approximately 0.8 cpm. - Highlights: • An approach roughly a factor of three more efficient than an un-optimized method. • The optimization gives a more efficient use of instrument time. • The efficiency increase ranges from a factor of three to 10, for 10 to 40 samples.

  8. Sequential processing of quantitative phase images for the study of cell behaviour in real-time digital holographic microscopy.

    Science.gov (United States)

    Zikmund, T; Kvasnica, L; Týč, M; Křížová, A; Colláková, J; Chmelík, R

    2014-11-01

    Transmitted light holographic microscopy is particularly used for quantitative phase imaging of transparent microscopic objects such as living cells. The study of the cell is based on extraction of the dynamic data on cell behaviour from the time-lapse sequence of the phase images. However, the phase images are affected by the phase aberrations that make the analysis particularly difficult. This is because the phase deformation is prone to change during long-term experiments. Here, we present a novel algorithm for sequential processing of living cells phase images in a time-lapse sequence. The algorithm compensates for the deformation of a phase image using weighted least-squares surface fitting. Moreover, it identifies and segments the individual cells in the phase image. All these procedures are performed automatically and applied immediately after obtaining every single phase image. This property of the algorithm is important for real-time cell quantitative phase imaging and instantaneous control of the course of the experiment by playback of the recorded sequence up to actual time. Such operator's intervention is a forerunner of process automation derived from image analysis. The efficiency of the propounded algorithm is demonstrated on images of rat fibrosarcoma cells using an off-axis holographic microscope. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  9. Sequential double excitations from linear-response time-dependent density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera, Martín A.; Ratner, Mark A.; Schatz, George C., E-mail: g-schatz@northwestern.edu [Department of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208 (United States); Chen, Lin X. [Department of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208 (United States); Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Ave., Lemont, Illinois 60439 (United States)

    2016-05-28

    Traditional UV/vis and X-ray spectroscopies focus mainly on the study of excitations starting exclusively from electronic ground states. However there are many experiments where transitions from excited states, both absorption and emission, are probed. In this work we develop a formalism based on linear-response time-dependent density functional theory to investigate spectroscopic properties of excited states. We apply our model to study the excited-state absorption of a diplatinum(II) complex under X-rays, and transient vis/UV absorption of pyrene and azobenzene.

  10. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: an interrupted time series over a 10-year period

    NARCIS (Netherlands)

    Helder, Onno K.; Brug, Johannes; van Goudoever, Johannes B.; Looman, Caspar W. N.; Reiss, Irwin K. M.; Kornelisse, René F.

    2014-01-01

    Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. An observational study with an interrupted time series

  11. Predicting the Location and Time of Mobile Phone Users by Using Sequential Pattern Mining Techniques

    DEFF Research Database (Denmark)

    Ozer, Mert; Keles, Ilkcan; Toroslu, Hakki

    2016-01-01

    In recent years, using cell phone log data to model human mobility patterns became an active research area. This problem is a challenging data mining problem due to huge size and non-uniformity of the log data, which introduces several granularity levels for the specification of temporal...... and spatial dimensions. This paper focuses on the prediction of the location of the next activity of the mobile phone users. There are several versions of this problem. In this work, we have concentrated on the following three problems: predicting the location and the time of the next user activity...... the success of these methods with real data obtained from one of the largest mobile phone operators in Turkey. Our results are very encouraging, since we were able to obtain quite high accuracy results under small prediction sets....

  12. When Time Flies: How Abstract and Concrete Mental Construal Affect the Perception of Time

    Science.gov (United States)

    Hansen, Jochim; Trope, Yaacov

    2013-01-01

    Time is experienced as passing more quickly the more changes happen in a situation. The present research tested the idea that time perception depends on the level of construal of the situation. Building on previous research showing that concrete rather than abstract mental construal causes people to perceive more variations in a given situation,…

  13. Prospective and retrospective time perception are related to mental time travel: evidence from Alzheimer's disease.

    Science.gov (United States)

    El Haj, Mohamad; Moroni, Christine; Samson, Séverine; Fasotti, Luciano; Allain, Philippe

    2013-10-01

    Unlike prospective time perception paradigms, in which participants are aware that they have to estimate forthcoming time, little is known about retrospective time perception in normal aging and Alzheimer's disease (AD). Our paper addresses this shortcoming by comparing prospective and retrospective time estimation in younger adults, older adults, and AD patients. In four prospective tasks (lasting 30s, 60s, 90s, or 120s) participants were asked to read a series of numbers and to provide a verbal estimation of the reading time. In four other retrospective tasks, they were not informed about time judgment until they were asked to provide a verbal estimation of four elapsed time intervals (lasting 30s, 60s, 90s, or 120s). AD participants gave shorter verbal time estimations than older adults and younger participants did, suggesting that time is perceived to pass quickly in these patients. For all participants, the duration of the retrospective tasks was underestimated as compared to the prospective tasks and both estimations were shorter than the real time interval. Prospective time estimation was further correlated with mental time travel, as measured with the Remember/Know paradigm. Mental time travel was even higher correlated with retrospective time estimation. Our findings shed light on the relationship between time perception and the ability to mentally project oneself into time, two skills contributing to human memory functioning. Finally, time perception deficits, as observed in AD patients, can be interpreted in terms of dramatic changes occurring in frontal lobes and hippocampus. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. The Perception of Time: Influences on Physical and Mental Health

    Directory of Open Access Journals (Sweden)

    Cristián Rodrigo Oyanadel Véliz

    2011-01-01

    Full Text Available With a broad understanding of time perception, the dimensions positive past, negative past, fatalistic present, hedonistic present and future were grouped in profiles to assess relations with physical and mental health. Using a quasi-experimental design, 50 subjects matched for age and sex completed the Zimbardo Time Perspective Inventory and the SF-36, with 3 measures of time estimation. Pearson correlations and ANOVA showed significant relationships between dimensions, physical and mental health, and estimation. Three profiles were obtained, with the balanced one (BTP having the best health indicators. These results support the idea that it is good to have a balanced profile that implies a positive attitude to the past, future orientation, and enjoying pleasant experiences. Also, health is influenced by time estimation

  15. Age, time period, and birth cohort differences in self-esteem: Reexamining a cohort-sequential longitudinal study.

    Science.gov (United States)

    Twenge, Jean M; Carter, Nathan T; Campbell, W Keith

    2017-05-01

    Orth, Trzesniewski, and Robins (2010) concluded that the nationally representative Americans' Changing Lives (ACL) cohort-sequential study demonstrated moderate to large age differences in self-esteem, and no birth cohort (generational) differences in the age trajectory. In a reanalysis of these data using 2 different statistical techniques, we find significant increases in self-esteem that could be attributed to birth cohort or time period. First, hierarchical linear modeling analyses with birth cohort as a continuous variable (vs. the multiple group formulation used by Orth et al.) find that birth cohort has a measurable influence on self-esteem through its interaction with age. Participants born in later years (e.g., 1960) were higher in self-esteem and were more likely to increase in self-esteem as they aged than participants born in earlier years (e.g., 1920). However, the estimated age trajectory up to age 60 is similar in Orth et al.'s results and in the results from our analyses including cohort. Second, comparing ACL respondents of the same age in 1986 versus 2002 (a time-lag design) yields significant birth cohort differences in self-esteem, with 2002 participants of the same age higher in self-esteem than those in 1986. Combined with some previous studies finding significant increases in self-esteem and positive self-views over time, these results suggest that cultural change in the form of cohort and time period cannot be ignored as influences in cross-sectional and longitudinal studies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Time perception and dynamics of facial expressions of emotions.

    Directory of Open Access Journals (Sweden)

    Sophie L Fayolle

    Full Text Available Two experiments were run to examine the effects of dynamic displays of facial expressions of emotions on time judgments. The participants were given a temporal bisection task with emotional facial expressions presented in a dynamic or a static display. Two emotional facial expressions and a neutral expression were tested and compared. Each of the emotional expressions had the same affective valence (unpleasant, but one was high-arousing (expressing anger and the other low-arousing (expressing sadness. Our results showed that time judgments are highly sensitive to movements in facial expressions and the emotions expressed. Indeed, longer perceived durations were found in response to the dynamic faces and the high-arousing emotional expressions compared to the static faces and low-arousing expressions. In addition, the facial movements amplified the effect of emotions on time perception. Dynamic facial expressions are thus interesting tools for examining variations in temporal judgments in different social contexts.

  17. Feel the Time. Time Perception as a Function of Interoceptive Processing

    Directory of Open Access Journals (Sweden)

    Daniele Di Lernia

    2018-03-01

    Full Text Available The nature of time is rooted in our body. Constellations of impulses arising from the flesh constantly create our interoceptive perception and, in turn, the unfolding of these perceptions defines human awareness of time. This study explored the connection between time perception and interoception and proposes the Interoceptive Buffer saturation (IBs index. IBs evaluates subjects’ ability to process salient stimuli from the body by measuring subjective distortions of interoceptive time perception, i.e., the estimated duration of tactile interoceptive stimulations. Thirty female healthy subjects were recruited through consecutive sampling and assessed for common variables related to interoceptive alterations: depressive symptoms (Beck Depression Inventory, BDI-II, eating disorders (EDI-3 risk, and anxiety levels (State Trait Anxiety Inventory, STAI. Interoceptive cardiac accuracy (IAc was assessed as well. Subjects performed verbal time estimation of interoceptive stimuli (IBs delivered using a specifically designed interoceptive tactile stimulator, as well as verbal time estimation of visual and auditory stimuli. Results showed that IBs index positively correlated with IAc, and negatively with EDI-3 Drive for Thinness (DT risk subscale. Moreover, IBs index was positively predicted by IAc, and negatively predicted by DT and somatic factors of depression. Our results suggest that underestimations in interoceptive time perception are connected to different psychological conditions characterized by a diminished processing of high salience stimuli from the body. Conversely, overestimations of the duration of interoceptive stimuli appear to be function of subjects’ ability to correctly perceive their own bodily information. Evidence supported IBs index, fostering the concept of interoceptive treatments for clinical purposes.

  18. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: An interrupted time series over a 10-year period

    NARCIS (Netherlands)

    Helder, O.K.; Brug, J.; van Goudoever, J.B.; Looman, C.W.N.; Reiss, I.K.M.; Kornelisse, R.F.

    2014-01-01

    Background Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. Methods An observational study with an interrupted

  19. The Perception of Time While Perceiving Dynamic Emotional Faces

    Directory of Open Access Journals (Sweden)

    Wang On eLi

    2015-08-01

    Full Text Available Emotion plays an essential role in the perception of time such that time is perceived to fly when events are enjoyable, while unenjoyable moments are perceived to drag. Previous studies have reported a time-drag effect when participants are presented with emotional facial expressions, regardless of the emotion presented. This effect can hardly be explained by induced emotion given the heterogeneous nature of emotional expressions. We conducted two experiments (n=44 & n=39 to examine the cognitive mechanism underlying this effect by presenting dynamic sequences of emotional expressions to participants. Each sequence started with a particular expression, then morphed to another. The presentation of dynamic facial expressions allows a comparison between the time-drag effect of homogeneous pairs of emotional expressions sharing similar valence and arousal to heterogeneous pairs. Sequences of seven durations (400ms, 600ms, 800ms, 1,000ms, 1,200ms, 1,400ms, 1,600ms were presented to participants, who were asked to judge whether the sequences were closer to 400ms or 1,600ms in a two-alternative forced choice task. The data were then collated according to conditions and fit into cumulative Gaussian curves to estimate the point of subjective equivalence indicating the perceived duration of 1,000ms. Consistent with previous reports, a feeling of time dragging is induced regardless of the sequence presented, such that 1,000ms is perceived to be longer than 1,000ms. In addition, dynamic facial expressions exert a greater effect on perceived time drag than static expressions. The effect is most prominent when the dynamics involve an angry face or a change in valence. The significance of this sensitivity is discussed in terms of emotion perception and its evolutionary significance for our attention mechanism.

  20. Academic Workload and Working Time: Retrospective Perceptions versus Time-Series Data

    Science.gov (United States)

    Kyvik, Svein

    2013-01-01

    The purpose of this article is to examine the validity of perceptions by academic staff about their past and present workload and working hours. Retrospective assessments are compared with time-series data. The data are drawn from four mail surveys among academic staff in Norwegian universities undertaken in the period 1982-2008. The findings show…

  1. FIRST TIME ONLINE LEARNERS’ PERCEPTIONS OF SUPPORT SERVICES PROVIDED

    Directory of Open Access Journals (Sweden)

    Stephanie HUNTE

    2012-04-01

    Full Text Available The number of online continuous education and training initiatives continues to increase in Caribbean Small Island Developing States (SIDS and by extension, the number of adult learners who are unfamiliar with the peculiarities of the online teaching and learning environment. The extent to which these learners can derive maximum benefit from these initiatives depends on the rate at which they can adapt to the new circumstances and, as a result, function effectively in this type of teaching and learning environment. To this end, while supporting learners is recognized as a critical success factor little has been explored or documented specific to the Caribbean-SIDS context. The purpose of this study therefore was to describe the support services provided first time online learners in the context of Caribbean-SIDS and examine what if any benefit learners derived from them through their perceptions of these services. The findings reveal that participants’ overall perception of the support services was high. They also reveal that although participants’ awareness of ongoing support services was variable, their rating of the need for and importance of this type of support was also high. The findings suggest that providing support for first time online learners in the context of Caribbean SIDS positively impacts their performance in the online teaching and learning environment.

  2. As time goes by: Oxytocin influences the subjective perception of time in a social context.

    Science.gov (United States)

    Colonnello, Valentina; Domes, Gregor; Heinrichs, Markus

    2016-06-01

    Time perception depends on an event's emotional relevance to the beholder; a subjective time dilation effect is associated with self-relevant, emotionally salient stimuli. Previous studies have revealed that oxytocin modulates the salience of social stimuli and attention to social cues. However, whether the oxytocin system is involved in human subjective time perception is unknown. The aim of the present study was to investigate whether increased oxytocin levels would induce a time dilation effect for self-relevant, positive social cues. In a double-blind, placebo-controlled, between-subject design, heterosexual men were administered intranasal oxytocin or placebo. After about 50min, participants completed a time-bisection task in which they estimated lengths of exposure to happy female faces (self-relevant positive stimuli, based on sexual orientation), emotionally neutral and negative female faces (control), and happy, neutral, and negative male faces (control). Oxytocin induced a subjective time dilation effect for happy female faces and a time compression effect for happy male faces. Our results provide evidence that oxytocin influences time perception, a primary form of human subjectivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Sequential injection analysis for automation of the Winkler methodology, with real-time SIMPLEX optimization and shipboard application

    Energy Technology Data Exchange (ETDEWEB)

    Horstkotte, Burkhard; Tovar Sanchez, Antonio; Duarte, Carlos M. [Department of Global Change Research, IMEDEA (CSIC-UIB) Institut Mediterrani d' Estudis Avancats, Miquel Marques 21, 07190 Esporles (Spain); Cerda, Victor, E-mail: Victor.Cerda@uib.es [University of the Balearic Islands, Department of Chemistry Carreterra de Valldemossa km 7.5, 07011 Palma de Mallorca (Spain)

    2010-01-25

    A multipurpose analyzer system based on sequential injection analysis (SIA) for the determination of dissolved oxygen (DO) in seawater is presented. Three operation modes were established and successfully applied onboard during a research cruise in the Southern ocean: 1st, in-line execution of the entire Winkler method including precipitation of manganese (II) hydroxide, fixation of DO, precipitate dissolution by confluent acidification, and spectrophotometric quantification of the generated iodine/tri-iodide (I{sub 2}/I{sub 3}{sup -}), 2nd, spectrophotometric quantification of I{sub 2}/I{sub 3}{sup -} in samples prepared according the classical Winkler protocol, and 3rd, accurate batch-wise titration of I{sub 2}/I{sub 3}{sup -} with thiosulfate using one syringe pump of the analyzer as automatic burette. In the first mode, the zone stacking principle was applied to achieve high dispersion of the reagent solutions in the sample zone. Spectrophotometric detection was done at the isobestic wavelength 466 nm of I{sub 2}/I{sub 3}{sup -}. Highly reduced consumption of reagents and sample compared to the classical Winkler protocol, linear response up to 16 mg L{sup -1} DO, and an injection frequency of 30 per hour were achieved. It is noteworthy that for the offline protocol, sample metering and quantification with a potentiometric titrator lasts in general over 5 min without counting sample fixation, incubation, and glassware cleaning. The modified SIMPLEX methodology was used for the simultaneous optimization of four volumetric and two chemical variables. Vertex calculation and consequent application including in-line preparation of one reagent was carried out in real-time using the software AutoAnalysis. The analytical system featured high signal stability, robustness, and a repeatability of 3% RSD (1st mode) and 0.8% (2nd mode) during shipboard application.

  4. Sequential injection analysis for automation of the Winkler methodology, with real-time SIMPLEX optimization and shipboard application

    International Nuclear Information System (INIS)

    Horstkotte, Burkhard; Tovar Sanchez, Antonio; Duarte, Carlos M.; Cerda, Victor

    2010-01-01

    A multipurpose analyzer system based on sequential injection analysis (SIA) for the determination of dissolved oxygen (DO) in seawater is presented. Three operation modes were established and successfully applied onboard during a research cruise in the Southern ocean: 1st, in-line execution of the entire Winkler method including precipitation of manganese (II) hydroxide, fixation of DO, precipitate dissolution by confluent acidification, and spectrophotometric quantification of the generated iodine/tri-iodide (I 2 /I 3 - ), 2nd, spectrophotometric quantification of I 2 /I 3 - in samples prepared according the classical Winkler protocol, and 3rd, accurate batch-wise titration of I 2 /I 3 - with thiosulfate using one syringe pump of the analyzer as automatic burette. In the first mode, the zone stacking principle was applied to achieve high dispersion of the reagent solutions in the sample zone. Spectrophotometric detection was done at the isobestic wavelength 466 nm of I 2 /I 3 - . Highly reduced consumption of reagents and sample compared to the classical Winkler protocol, linear response up to 16 mg L -1 DO, and an injection frequency of 30 per hour were achieved. It is noteworthy that for the offline protocol, sample metering and quantification with a potentiometric titrator lasts in general over 5 min without counting sample fixation, incubation, and glassware cleaning. The modified SIMPLEX methodology was used for the simultaneous optimization of four volumetric and two chemical variables. Vertex calculation and consequent application including in-line preparation of one reagent was carried out in real-time using the software AutoAnalysis. The analytical system featured high signal stability, robustness, and a repeatability of 3% RSD (1st mode) and 0.8% (2nd mode) during shipboard application.

  5. Visual Timing of Structured Dance Movements Resembles Auditory Rhythm Perception

    Science.gov (United States)

    Su, Yi-Huang; Salazar-López, Elvira

    2016-01-01

    Temporal mechanisms for processing auditory musical rhythms are well established, in which a perceived beat is beneficial for timing purposes. It is yet unknown whether such beat-based timing would also underlie visual perception of temporally structured, ecological stimuli connected to music: dance. In this study, we investigated whether observers extracted a visual beat when watching dance movements to assist visual timing of these movements. Participants watched silent videos of dance sequences and reproduced the movement duration by mental recall. We found better visual timing for limb movements with regular patterns in the trajectories than without, similar to the beat advantage for auditory rhythms. When movements involved both the arms and the legs, the benefit of a visual beat relied only on the latter. The beat-based advantage persisted despite auditory interferences that were temporally incongruent with the visual beat, arguing for the visual nature of these mechanisms. Our results suggest that visual timing principles for dance parallel their auditory counterparts for music, which may be based on common sensorimotor coupling. These processes likely yield multimodal rhythm representations in the scenario of music and dance. PMID:27313900

  6. Time perception, attention, and memory: a selective review.

    Science.gov (United States)

    Block, Richard A; Gruber, Ronald P

    2014-06-01

    This article provides a selective review of time perception research, mainly focusing on the authors' research. Aspects of psychological time include simultaneity, successiveness, temporal order, and duration judgments. In contrast to findings at interstimulus intervals or durations less than 3.0-5.0 s, there is little evidence for an "across-senses" effect of perceptual modality (visual vs. auditory) at longer intervals or durations. In addition, the flow of time (events) is a pervasive perceptual illusion, and we review evidence on that. Some temporal information is encoded All rights reserved. relatively automatically into memory: People can judge time-related attributes such as recency, frequency, temporal order, and duration of events. Duration judgments in prospective and retrospective paradigms reveal differences between them, as well as variables that moderate the processes involved. An attentional-gate model is needed to account for prospective judgments, and a contextual-change model is needed to account for retrospective judgments. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Sequential Banking.

    OpenAIRE

    Bizer, David S; DeMarzo, Peter M

    1992-01-01

    The authors study environments in which agents may borrow sequentially from more than one leader. Although debt is prioritized, additional lending imposes an externality on prior debt because, with moral hazard, the probability of repayment of prior loans decreases. Equilibrium interest rates are higher than they would be if borrowers could commit to borrow from at most one bank. Even though the loan terms are less favorable than they would be under commitment, the indebtedness of borrowers i...

  8. Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment.

    Science.gov (United States)

    Glicksohn, Joseph; Berkovich-Ohana, Aviva; Mauro, Federica; Ben-Soussan, Tal D

    2017-01-01

    The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min), followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP) task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log-log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as "the sensation of time disappeared," their TP data could not be linearized using a log-log plot, hence indicating that for these

  9. Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment

    Directory of Open Access Journals (Sweden)

    Joseph Glicksohn

    2017-10-01

    Full Text Available The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min, followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log–log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as “the sensation of time disappeared,” their TP data could not be linearized using a log–log plot, hence

  10. Integration time for the perception of depth from motion parallax.

    Science.gov (United States)

    Nawrot, Mark; Stroyan, Keith

    2012-04-15

    The perception of depth from relative motion is believed to be a slow process that "builds-up" over a period of observation. However, in the case of motion parallax, the potential accuracy of the depth estimate suffers as the observer translates during the viewing period. Our recent quantitative model for the perception of depth from motion parallax proposes that relative object depth (d) can be determined from retinal image motion (dθ/dt), pursuit eye movement (dα/dt), and fixation distance (f) by the formula: d/f≈dθ/dα. Given the model's dynamics, it is important to know the integration time required by the visual system to recover dα and dθ, and then estimate d. Knowing the minimum integration time reveals the incumbent error in this process. A depth-phase discrimination task was used to determine the time necessary to perceive depth-sign from motion parallax. Observers remained stationary and viewed a briefly translating random-dot motion parallax stimulus. Stimulus duration varied between trials. Fixation on the translating stimulus was monitored and enforced with an eye-tracker. The study found that relative depth discrimination can be performed with presentations as brief as 16.6 ms, with only two stimulus frames providing both retinal image motion and the stimulus window motion for pursuit (mean range=16.6-33.2 ms). This was found for conditions in which, prior to stimulus presentation, the eye was engaged in ongoing pursuit or the eye was stationary. A large high-contrast masking stimulus disrupted depth-discrimination for stimulus presentations less than 70-75 ms in both pursuit and stationary conditions. This interval might be linked to ocular-following response eye-movement latencies. We conclude that neural mechanisms serving depth from motion parallax generate a depth estimate much more quickly than previously believed. We propose that additional sluggishness might be due to the visual system's attempt to determine the maximum dθ/dα ratio

  11. Abrupt category shifts during real-time person perception.

    Science.gov (United States)

    Freeman, Jonathan B

    2014-02-01

    Previous studies have suggested that real-time person perception relies on continuous competition, in which partially active categories smoothly compete over time. Here, two studies demonstrated the involvement of a different kind of competition. In Study 1, before participants selected the correct sex category for morphed faces, their mouse trajectories often exhibited a continuous attraction toward the incorrect category that increased with sex-category ambiguity, indicating continuous competition. On other trials, however, trajectories initially pursued the incorrect category and then abruptly redirected toward the correct category, suggesting early incorrect category activation that was rapidly reversed later in processing. These abrupt category reversals also increased with ambiguity. In Study 2, participants were presented with faces containing a sex-typical or sex-atypical hair cue, in a context in which the norm was either sex-typical targets (normative context) or sex-atypical targets (counternormative context). Sex-atypical targets induced greater competition in the normative context, but sex-typical targets induced greater competition in the counternormative context. Together, these results demonstrate that categorizing others involves both smooth competition and abrupt category shifts, and that these flexibly adapt to the social context.

  12. Is seeing believing? Perceptions of wildfire risk over time

    Science.gov (United States)

    Patricia A. Champ; Hannah Brenkert-Smith

    2016-01-01

    Ongoing challenges to understanding how hazard exposure and disaster experiences influence perceived risk lead us to ask: Is seeing believing? We approach risk perception by attending to two components of overall risk perception: perceived probability of an event occurring and perceived consequences if an event occurs. Using a two-period longitudinal data set...

  13. Time perception and psychopathology: Influence of time perspective on quality of life of severe mental illness.

    Science.gov (United States)

    Oyanadel, Cristián; Buela-Casal, Gualberto

    2014-01-01

    The study of time perception and mental illness has given priority to time estimation over time perspective. Considering Zimbardo’s theory on five dimensions of time perspective, and balanced time perspective profile, this study has aimed to compare people with severe mental illness (SMI) and healthy people, with measurements of time perspective and time estimation and to assess whether the time perspective profile influences the quality of life in people with SMI. Using a quasi-experimental design, a clinical group (n=167) corresponding to four samples of severe mental disorders (major depression, bipolar disorder, schizophrenia and personality disorders) and healthy people (n=167) were compared in their performance regarding time perspective and time estimation. After, the clinical sample was grouped according to their deviation from the balanced time perspective profile (DBTP) and negative profile (DNTP). These groups were evaluated with health measures and time estimation tasks. Through the ANOVA, it can be seen that the time perspective profile affects health measurements. There are significant differences between the clinical sample and controls regarding time perspective and time estimation. Within the group of patients, it was observed that those who were closer to the BTP profile had better physical health, and less hopelessness (ptime perspective in the assessment, treatment and quality of life of people with SMI.

  14. Perceptions of Life Changes: An Alternate Measure of Aging through Time.

    Science.gov (United States)

    Suggs, Patricia K.; Kivett, Vira R.

    Retrospective strategies measuring perceived life changes over time can further the advancement of life span developmental research. Researchers have neglected the individual's perception of his/her life changes over time. This study attempts to determine discriminators of change over time as operationalized by perceptions of change. Subjects…

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

    Directory of Open Access Journals (Sweden)

    Meredith S Berry

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

  16. Noninferiority, randomized, controlled trial comparing embryo development using media developed for sequential or undisturbed culture in a time-lapse setup.

    Science.gov (United States)

    Hardarson, Thorir; Bungum, Mona; Conaghan, Joe; Meintjes, Marius; Chantilis, Samuel J; Molnar, Laszlo; Gunnarsson, Kristina; Wikland, Matts

    2015-12-01

    To study whether a culture medium that allows undisturbed culture supports human embryo development to the blastocyst stage equivalently to a well-established sequential media. Randomized, double-blinded sibling trial. Independent in vitro fertilization (IVF) clinics. One hundred twenty-eight patients, with 1,356 zygotes randomized into two study arms. Embryos randomly allocated into two study arms to compare embryo development on a time-lapse system using a single-step medium or sequential media. Percentage of good-quality blastocysts on day 5. Percentage of day 5 good-quality blastocysts was 21.1% (standard deviation [SD] ± 21.6%) and 22.2% (SD ± 22.1%) in the single-step time-lapse medium (G-TL) and the sequential media (G-1/G-2) groups, respectively. The mean difference (-1.2; 95% CI, -6.0; 3.6) between the two media systems for the primary end point was less than the noninferiority margin of -8%. There was a statistically significantly lower number of good-quality embryos on day 3 in the G-TL group [50.7% (SD ± 30.6%) vs. 60.8% (SD ± 30.7%)]. Four out of the 11 measured morphokinetic parameters were statistically significantly different for the two media used. The mean levels of ammonium concentration in the media at the end of the culture period was statistically significantly lower in the G-TL group as compared with the G-2 group. We have shown that a single-step culture medium supports blastocyst development equivalently to established sequential media. The ammonium concentrations were lower in the single-step media, and the measured morphokinetic parameters were modified somewhat. NCT01939626. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Sequential Dependencies in Driving

    Science.gov (United States)

    Doshi, Anup; Tran, Cuong; Wilder, Matthew H.; Mozer, Michael C.; Trivedi, Mohan M.

    2012-01-01

    The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find…

  18. Oscillatory phase dynamics in neural entrainment underpin illusory percepts of time.

    Science.gov (United States)

    Herrmann, Björn; Henry, Molly J; Grigutsch, Maren; Obleser, Jonas

    2013-10-02

    Neural oscillatory dynamics are a candidate mechanism to steer perception of time and temporal rate change. While oscillator models of time perception are strongly supported by behavioral evidence, a direct link to neural oscillations and oscillatory entrainment has not yet been provided. In addition, it has thus far remained unaddressed how context-induced illusory percepts of time are coded for in oscillator models of time perception. To investigate these questions, we used magnetoencephalography and examined the neural oscillatory dynamics that underpin pitch-induced illusory percepts of temporal rate change. Human participants listened to frequency-modulated sounds that varied over time in both modulation rate and pitch, and judged the direction of rate change (decrease vs increase). Our results demonstrate distinct neural mechanisms of rate perception: Modulation rate changes directly affected listeners' rate percept as well as the exact frequency of the neural oscillation. However, pitch-induced illusory rate changes were unrelated to the exact frequency of the neural responses. The rate change illusion was instead linked to changes in neural phase patterns, which allowed for single-trial decoding of percepts. That is, illusory underestimations or overestimations of perceived rate change were tightly coupled to increased intertrial phase coherence and changes in cerebro-acoustic phase lag. The results provide insight on how illusory percepts of time are coded for by neural oscillatory dynamics.

  19. Time perception in patients with major depressive disorder during vagus nerve stimulation.

    Science.gov (United States)

    Biermann, T; Kreil, S; Groemer, T W; Maihöfner, C; Richter-Schmiedinger, T; Kornhuber, J; Sperling, W

    2011-07-01

    Affective disorders may affect patients' time perception. Several studies have described time as a function of the frontal lobe. The activating eff ects of vagus nerve stimulation on the frontal lobe might also modulate time perception in patients with major depressive disorder (MDD). Time perception was investigated in 30 patients with MDD and in 7 patients with therapy-resistant MDD. In these 7 patients, a VNS system was implanted and time perception was assessed before and during stimulation. A time estimation task in which patients were asked "How many seconds have passed?" tested time perception at 4 defined time points (34 s, 77 s, 192 s and 230 s). The differences between the estimated and actual durations were calculated and used for subsequent analysis. Patients with MDD and healthy controls estimated the set time points relatively accurately. A general linear model revealed a significant main eff ect of group but not of age or sex. The passing of time was perceived as significantly slower in patients undergoing VNS compared to patients with MDD at all time points (T34: t = − 4.2; df = 35; p differences in time perception with regard to age, sex or polarity of depression (uni- or bipolar). VNS is capable of changing the perception of time. This discovery furthers the basic research on circadian rhythms in patients with psychiatric disorders.

  20. Linguistic Means of Depersonalization and Dematerialization in the Descriptions of Subjective Perception of Time

    Directory of Open Access Journals (Sweden)

    Ella V. Nesterik

    2013-01-01

    Full Text Available This article analyses linguistic means of depersonalization and dematerialization in the descriptions of subjective perception of time by characters, detects functions, fulfilled by them in such contexts. Subjective perception of time is considered as a text category and is studied in terms of text linguistics

  1. Operational reliability evaluation of restructured power systems with wind power penetration utilizing reliability network equivalent and time-sequential simulation approaches

    DEFF Research Database (Denmark)

    Ding, Yi; Cheng, Lin; Zhang, Yonghong

    2014-01-01

    In the last two decades, the wind power generation has been rapidly and widely developed in many regions and countries for tackling the problems of environmental pollution and sustainability of energy supply. However, the high share of intermittent and fluctuating wind power production has also...... and reserve provides, fast reserve providers and transmission network in restructured power systems. A contingency management schema for real time operation considering its coupling with the day-ahead market is proposed. The time-sequential Monte Carlo simulation is used to model the chronological...

  2. Multi-agent sequential hypothesis testing

    KAUST Repository

    Kim, Kwang-Ki K.; Shamma, Jeff S.

    2014-01-01

    incorporate costs of taking private/public measurements, costs of time-difference and disagreement in actions of agents, and costs of false declaration/choices in the sequential hypothesis testing. The corresponding sequential decision processes have well

  3. A real-time comparison between direct control, sequential pattern recognition control and simultaneous pattern recognition control using a Fitts' law style assessment procedure.

    Science.gov (United States)

    Wurth, Sophie M; Hargrove, Levi J

    2014-05-30

    Pattern recognition (PR) based strategies for the control of myoelectric upper limb prostheses are generally evaluated through offline classification accuracy, which is an admittedly useful metric, but insufficient to discuss functional performance in real time. Existing functional tests are extensive to set up and most fail to provide a challenging, objective framework to assess the strategy performance in real time. Nine able-bodied and two amputee subjects gave informed consent and participated in the local Institutional Review Board approved study. We designed a two-dimensional target acquisition task, based on the principles of Fitts' law for human motor control. Subjects were prompted to steer a cursor from the screen center of into a series of subsequently appearing targets of different difficulties. Three cursor control systems were tested, corresponding to three electromyography-based prosthetic control strategies: 1) amplitude-based direct control (the clinical standard of care), 2) sequential PR control, and 3) simultaneous PR control, allowing for a concurrent activation of two degrees of freedom (DOF). We computed throughput (bits/second), path efficiency (%), reaction time (second), and overshoot (%)) and used general linear models to assess significant differences between the strategies for each metric. We validated the proposed methodology by achieving very high coefficients of determination for Fitts' law. Both PR strategies significantly outperformed direct control in two-DOF targets and were more intuitive to operate. In one-DOF targets, the simultaneous approach was the least precise. The direct control was efficient in one-DOF targets but cumbersome to operate in two-DOF targets through a switch-depended sequential cursor control. We designed a test, capable of comprehensively describing prosthetic control strategies in real time. When implemented on control subjects, the test was able to capture statistically significant differences (p

  4. Engaging narratives evoke similar neural activity and lead to similar time perception.

    Science.gov (United States)

    Cohen, Samantha S; Henin, Simon; Parra, Lucas C

    2017-07-04

    It is said that we lose track of time - that "time flies" - when we are engrossed in a story. How does engagement with the story cause this distorted perception of time, and what are its neural correlates? People commit both time and attentional resources to an engaging stimulus. For narrative videos, attentional engagement can be represented as the level of similarity between the electroencephalographic responses of different viewers. Here we show that this measure of neural engagement predicted the duration of time that viewers were willing to commit to narrative videos. Contrary to popular wisdom, engagement did not distort the average perception of time duration. Rather, more similar brain responses resulted in a more uniform perception of time across viewers. These findings suggest that by capturing the attention of an audience, narrative videos bring both neural processing and the subjective perception of time into synchrony.

  5. Exploring the Effects of Working Memory on Time Perception in Attention Deficit Hyperactivity Disorder.

    Science.gov (United States)

    Lee, Hom-Yi; Yang, En-Lin

    2018-01-01

    Children with attention deficit hyperactivity disorder (ADHD) are often reported to have deficits of time perception. However, there is a strong relation between performance on tasks of working memory and time perception. Thus, it is possible that the poor performance of children with ADHD on time perception results from their deficit of working memory. In this study, the working memory of participants was separately assessed; therefore, we could explore the relationship between working memory and time perception of children with ADHD. Fifty-six children with ADHD and those of healthy controls completed tasks measuring working memory and time perception. The results showed that the time discrimination ability of children with ADHD was poorer than that of controls. However, there was a strong association between time perception and working memory. After controlling working memory and intelligence, the time discrimination ability of children with ADHD was not significantly poorer than that of controls. We suggest that there is an interdependent relationship between time perception and working memory for children with ADHD.

  6. Is Part-Time Child Care Surrogate Parenting? Parents' Perceptions.

    Science.gov (United States)

    Rana, Avis

    The purpose of this survey and report is to gain information about parental planning for child-rearing when the mother is employed. This study is intended to explore mothers' perceptions of possible delegation of some basic child-rearing functions during the mothers' absence for employment. Comparison of the child care arrangements which the…

  7. Modelling travel time perception in transport mode choices

    NARCIS (Netherlands)

    Varotto, S.F.; Glerum, A.; Stathopoulos, A.; Bierlaire, M.; Longo, G.

    2015-01-01

    Travel behaviour models typically rely on data afflicted by errors, in perception (e.g., over/under-estimation by traveller) and measurement (e.g., software or researcher imputation error). Such errors are shown to have a relevant impact on model outputs. So far a comprehensive framework to deal

  8. Dedicated clock/timing-circuit theories of time perception and timed performance

    NARCIS (Netherlands)

    van Rijn, Hedderik; Gu, Bon-Mi; Meck, Warren H

    2014-01-01

    Scalar Timing Theory (an information-processing version of Scalar Expectancy Theory) and its evolution into the neurobiologically plausible Striatal Beat-Frequency (SBF) theory of interval timing are reviewed. These pacemaker/accumulator or oscillation/coincidence detection models are then

  9. Dedicated clock/timing-circuit theories of time perception and timed performance.

    Science.gov (United States)

    van Rijn, Hedderik; Gu, Bon-Mi; Meck, Warren H

    2014-01-01

    Scalar Timing Theory (an information-processing version of Scalar Expectancy Theory) and its evolution into the neurobiologically plausible Striatal Beat-Frequency (SBF) theory of interval timing are reviewed. These pacemaker/accumulator or oscillation/coincidence detection models are then integrated with the Adaptive Control of Thought-Rational (ACT-R) cognitive architecture as dedicated timing modules that are able to make use of the memory and decision-making mechanisms contained in ACT-R. The different predictions made by the incorporation of these timing modules into ACT-R are discussed as well as the potential limitations. Novel implementations of the original SBF model that allow it to be incorporated into ACT-R in a more fundamental fashion than the earlier simulations of Scalar Timing Theory are also considered in conjunction with the proposed properties and neural correlates of the "internal clock".

  10. A research on motion design for APP's loading pages based on time perception

    Science.gov (United States)

    Cao, Huai; Hu, Xiaoyun

    2018-04-01

    Due to restrictions caused by objective reasons like network bandwidth, hardware performance and etc., waiting is still an inevitable phenomenon that appears in our using mobile-terminal products. Relevant researches show that users' feelings in a waiting scenario can affect their evaluations on the whole product and services the product provides. With the development of user experience and inter-facial design subjects, the role of motion effect in the interface design has attracted more and more scholars' attention. In the current studies, the research theory of motion design in a waiting scenario is imperfect. This article will use the basic theory and experimental research methods of cognitive psychology to explore the motion design's impact on user's time perception when users are waiting for loading APP pages. Firstly, the article analyzes the factors that affect waiting experience of loading APP pages based on the theory of time perception, and then discusses motion design's impact on the level of time-perception when loading pages and its design strategy. Moreover, by the operation analysis of existing loading motion designs, the article classifies the existing loading motions and designs an experiment to verify the impact of different types of motions on the user's time perception. The result shows that the waiting time perception of mobile's terminals' APPs is related to the loading motion types, the combination type of loading motions can effectively shorten the waiting time perception as it scores a higher mean value in the length of time perception.

  11. Perceptions of public transport travel time and their effect on choice-sets among car drivers

    NARCIS (Netherlands)

    N.J.A. van Exel (Job); P. Rietveld (Piet)

    2010-01-01

    textabstractCar drivers' perceptions of the quality of alternative travel modes have been identified as a barrier for including these alternatives in their choice sets. The present study investigated the accuracy of car drivers' perceptions of public transport (PT) travel time and the potential

  12. Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research

    OpenAIRE

    Harper, Liam D.; Fothergill, Melissa; West, Daniel J.; Stevenson, Emma; Russell, Mark

    2016-01-01

    Qualitative research investigating soccer practitioners’ perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time reg...

  13. The Perception of Time: Basic Research and Some Potential Links to the Study of Language

    Science.gov (United States)

    Wearden, J. H.

    2008-01-01

    The article first discusses some recent work in time perception--in particular the distinction among prospective timing, retrospective timing, and passage of time judgments. The history and application of an "internal clock" model as an explanation of prospective timing performance is reviewed and contrasted with the different mechanisms needed…

  14. [Physician and autonomy: on time perception and job satisfaction].

    Science.gov (United States)

    Huisman, Frank G

    2015-01-01

    Is it true that haste is sneaking into medicine? In this article, it is argued that it mainly concerns the perception of being rushed, which is caused by a loss of autonomy of the modern physician. In the fifties, physicians were busy as well, but because they enjoyed a greater degree of autonomy compared to their contemporary colleagues, they did not experience this in a negative way. Due to increased bureaucracy and the introduction of market dynamics, the medical profession has lost autonomy, which in turn led to a loss of job satisfaction.

  15. Time perception among the youth and its implication for industry: An exploratory study

    Directory of Open Access Journals (Sweden)

    GG Rousseau

    2004-04-01

    Full Text Available The main objective of this exploratory study was to investigate perceived cultural differences in the perception of time among the youth and its implications for time management and productivity regarding future employment in industry. The study further sought to develop a reliable instrument for measuring time perception across cultures.  A non-probability convenience sample (N=467 was drawn from English, Afrikaans and Xhosa speaking respondents, aged 13 to 18 years.  Results confirmed four factors: time allocation, time economy, time attitudes and scheduling of tasks.  Significant differences between age, language and gender groups on time perception were observed.  These findings have implications for time management training among the youth as well as for industry seeking employees who can perform tasks with speed and efficiency.  Further refinement of the instrument in follow-up studies is essential.

  16. Yeast Monitoring of Wine Mixed or Sequential Fermentations Made by Native Strains from D.O. “Vinos de Madrid” Using Real-Time Quantitative PCR

    Science.gov (United States)

    García, Margarita; Esteve-Zarzoso, Braulio; Crespo, Julia; Cabellos, Juan M.; Arroyo, Teresa

    2017-01-01

    There is an increasing trend toward understanding the impact of non-Saccharomyces yeasts on the winemaking process. Although Saccharomyces cerevisiae is the predominant species at the end of fermentation, it has been recognized that the presence of non-Saccharomyces species during alcoholic fermentation can produce an improvement in the quality and complexity of the final wines. A previous work was developed for selecting the best combinations between S. cerevisiae and five non-Saccharomyces (Torulaspora delbrueckii, Schizosaccharomyces pombe, Candida stellata, Metschnikowia pulcherrima, and Lachancea thermotolorans) native yeast strains from D.O. “Vinos de Madrid” at the laboratory scale. The best inoculation strategies between S. cerevisiae and non-Saccharomyces strains were chosen to analyze, by real-time quantitative PCR (qPCR) combined with the use of specific primers, the dynamics of inoculated populations throughout the fermentation process at the pilot scale using the Malvar white grape variety. The efficiency of the qPCR system was verified independently of the samples matrix, founding the inoculated yeast species throughout alcoholic fermentation. Finally, we can validate the positive effect of selected co-cultures in the Malvar wine quality, highlighting the sequential cultures of T. delbrueckii CLI 918/S. cerevisiae CLI 889 and C. stellata CLI 920/S. cerevisiae CLI 889 and, mixed and sequential cultures of L. thermotolerans 9-6C combined with S. cerevisiae CLI 889. PMID:29326669

  17. Yeast Monitoring of Wine Mixed or Sequential Fermentations Made by Native Strains from D.O. “Vinos de Madrid” Using Real-Time Quantitative PCR

    Directory of Open Access Journals (Sweden)

    Margarita García

    2017-12-01

    Full Text Available There is an increasing trend toward understanding the impact of non-Saccharomyces yeasts on the winemaking process. Although Saccharomyces cerevisiae is the predominant species at the end of fermentation, it has been recognized that the presence of non-Saccharomyces species during alcoholic fermentation can produce an improvement in the quality and complexity of the final wines. A previous work was developed for selecting the best combinations between S. cerevisiae and five non-Saccharomyces (Torulaspora delbrueckii, Schizosaccharomyces pombe, Candida stellata, Metschnikowia pulcherrima, and Lachancea thermotolorans native yeast strains from D.O. “Vinos de Madrid” at the laboratory scale. The best inoculation strategies between S. cerevisiae and non-Saccharomyces strains were chosen to analyze, by real-time quantitative PCR (qPCR combined with the use of specific primers, the dynamics of inoculated populations throughout the fermentation process at the pilot scale using the Malvar white grape variety. The efficiency of the qPCR system was verified independently of the samples matrix, founding the inoculated yeast species throughout alcoholic fermentation. Finally, we can validate the positive effect of selected co-cultures in the Malvar wine quality, highlighting the sequential cultures of T. delbrueckii CLI 918/S. cerevisiae CLI 889 and C. stellata CLI 920/S. cerevisiae CLI 889 and, mixed and sequential cultures of L. thermotolerans 9-6C combined with S. cerevisiae CLI 889.

  18. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: an interrupted time series over a 10-year period.

    Science.gov (United States)

    Helder, Onno K; Brug, Johannes; van Goudoever, Johannes B; Looman, Caspar W N; Reiss, Irwin K M; Kornelisse, René F

    2014-07-01

    Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. An observational study with an interrupted time series analysis of the occurrence of NBSI was performed in very low-birth weight (VLBW) infants. Interventions consisted of an education program, gain-framed screen saver messages, and an infection prevention week with an introduction on consistent glove use. A total of 1,964 VLBW infants admitted between January 1, 2002, and December 31, 2011, were studied. The proportion of infants with ≥1 NBSI decreased from 47.6%-21.2% (P Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  19. Relationship between Time Perception and Kirton's Adaption-Innovation Inventory.

    Science.gov (United States)

    Walling, M.; And Others

    Time production is an experimental paradigm that compares the accuracy with which a subject can produce a specified time interval relative to actual clock time. Higgins (1987) found that subjects perceived the passage of time as faster or slower, compared to actual time, as an interrelation of personality characteristics and experimental…

  20. Sequential Participation in a Multi-Institutional Mock Oral Examination Is Associated With Improved American Board of Surgery Certifying Examination First-Time Pass Rate.

    Science.gov (United States)

    Fingeret, Abbey L; Arnell, Tracey; McNelis, John; Statter, Mindy; Dresner, Lisa; Widmann, Warren

    We sought to determine whether sequential participation in a multi-institutional mock oral examination affected the likelihood of passing the American Board of Surgery Certifying Examination (ABSCE) in first attempt. Residents from 3 academic medical centers were able to participate in a regional mock oral examination in the fall and spring of their fourth and fifth postgraduate year from 2011 to 2014. Candidate׳s highest composite score of all mock orals attempts was classified as risk for failure, intermediate, or likely to pass. Factors including United States Medical Licensing Examination steps 1, 2, and 3, number of cases logged, American Board of Surgery In-Training Examination performance, American Board of Surgery Qualifying Examination (ABSQE) performance, number of attempts, and performance in the mock orals were assessed to determine factors predictive of passing the ABSCE. A total of 128 mock oral examinations were administered to 88 (71%) of 124 eligible residents. The overall first-time pass rate for the ABSCE was 82%. There was no difference in pass rates between participants and nonparticipants. Of them, 16 (18%) residents were classified as at risk, 47 (53%) as intermediate, and 25 (29%) as likely to pass. ABSCE pass rate for each group was as follows: 36% for at risk, 84% for intermediate, and 96% for likely pass. The following 4 factors were associated with first-time passing of ABSCE on bivariate analysis: mock orals participation in postgraduate year 4 (p = 0.05), sequential participation in mock orals (p = 0.03), ABSQE performance (p = 0.01), and best performance on mock orals (p = 0.001). In multivariable logistic regression, the following 3 factors remained associated with ABSCE passing: ABSQE performance, odds ratio (OR) = 2.9 (95% CI: 1.3-6.1); mock orals best performance, OR = 1.7 (1.2-2.4); and participation in multiple mock oral examinations, OR = 1.4 (1.1-2.7). Performance on a multi-institutional mock oral examination can identify

  1. Time Spent, Workload, and Student and Faculty Perceptions in a Blended Learning Environment

    Science.gov (United States)

    Schumacher, Christie; Arif, Sally

    2016-01-01

    Objective. To evaluate student perception and time spent on asynchronous online lectures in a blended learning environment (BLE) and to assess faculty workload and perception. Methods. Students (n=427) time spent viewing online lectures was measured in three courses. Students and faculty members completed a survey to assess perceptions of a BLE. Faculty members recorded time spent creating BLEs. Results. Total time spent in the BLE was less than the allocated time for two of the three courses by 3-15%. Students preferred online lectures for their flexibility, students’ ability to apply information learned, and congruence with their learning styles. Faculty members reported the BLE facilitated higher levels of learning during class sessions but noted an increase in workload. Conclusion. A BLE increased faculty workload but was well received by students. Time spent viewing online lectures was less than what was allocated in two of the three courses. PMID:27667839

  2. Motion perception and driving: predicting performance through testing and shortening braking reaction times through training.

    Science.gov (United States)

    Wilkins, Luke; Gray, Rob; Gaska, James; Winterbottom, Marc

    2013-12-30

    A driving simulator was used to examine the relationship between motion perception and driving performance. Although motion perception test scores have been shown to be related to driving safety, it is not clear which combination of tests are the best predictors and whether motion perception training can improve driving performance. In experiment 1, 60 younger drivers (22.4 ± 2.5 years) completed three motion perception tests (2-dimensional [2D] motion-defined letter [MDL] identification, 3D motion in depth sensitivity [MID], and dynamic visual acuity [DVA]) followed by two driving tests (emergency braking [EB] and hazard perception [HP]). In experiment 2, 20 drivers (21.6 ± 2.1 years) completed 6 weeks of motion perception training (using the MDL, MID, and DVA tests), while 20 control drivers (22.0 ± 2.7 years) completed an online driving safety course. The EB performance was measured before and after training. In experiment 1, MDL (r = 0.34) and MID (r = 0.46) significantly correlated with EB score. The change in DVA score as a function of target speed (i.e., "velocity susceptibility") was correlated most strongly with HP score (r = -0.61). In experiment 2, the motion perception training group had a significant decrease in brake reaction time on the EB test from pre- to posttreatment, while there was no significant change for the control group: t(38) = 2.24, P = 0.03. Tests of 3D motion perception are the best predictor of EB, while DVA velocity susceptibility is the best predictor of hazard perception. Motion perception training appears to result in faster braking responses.

  3. Dynamic analysis of mental sweating of eccrine sweat gland of human fingertip by time-sequential piled-up en face optical coherence tomography images.

    Science.gov (United States)

    Ohmi, Masato; Wada, Yuki

    2016-08-01

    In this paper, we demonstrate dynamic analysis of mental sweating for sound stimulus of a few tens of eccrine sweat glands by the time-sequential piled-up en face optical coherence tomography (OCT) images with the frame spacing of 3.3 sec. In the experiment, the amount of excess sweat can be evaluated simultaneously for a few tens of sweat glands by piling up of all the en face OCT images. Non-uniformity was observed in mental sweating where the amount of sweat in response to sound stimulus is different for each sweat gland. Furthermore, the amount of sweat is significantly increased in proportion to the strength of the stimulus.

  4. Determinants and stability over time of perception of health risks related to mobile phone base stations

    DEFF Research Database (Denmark)

    Kowall, Bernd; Breckenkamp, Jürgen; Blettner, Maria

    2012-01-01

    about other environmental and health risks, is associated with psychological strain, and is stable on the individual level over time. METHODS: Self-administered questionnaires filled in by 3,253 persons aged 15-69 years in 2004 and 2006 in Germany. RESULTS: Risk perception of MPBS was strongly......OBJECTIVE: Perception of possible health risks related to mobile phone base stations (MPBS) is an important factor in citizens' opposition against MPBS and is associated with health complaints. The aim of the present study is to assess whether risk perception of MPBS is associated with concerns...... in 2004 expressed these concerns again 2 years later, the corresponding figure for attribution of health complaints to MPBS was 31.3%. CONCLUSION: Risk perception of MPBS is strongly associated with general concern, anxiety, depression, and stress, and rather instable over time....

  5. The influence of social stress on time perception and psychophysiological reactivity.

    Science.gov (United States)

    van Hedger, Kathryne; Necka, Elizabeth A; Barakzai, Anam K; Norman, Greg J

    2017-05-01

    Time perception is a fundamental component of everyday life. Although time can be measured using standard units, the relationship between an individual's experience of perceived time and a standard unit is highly sensitive to context. Stressful and threatening stimuli have been previously shown to produce time distortion effects, such that individuals perceive the stimuli as lasting for different amounts of time as compared to a standard unit. As a highly social species, humans are acutely sensitive to social stressors; however, time distortion effects have not been studied in the context of social stress. We collected psychophysiological (electrocardiogram and impedance cardiography) and time perception data before, during, and after a modified version of the Trier Social Stress Test for 42 participants. Based on prior theories and evidence from the time perception literature, we hypothesized that experiencing a stressful event would result in time distortion. This hypothesis was supported by the data, with individuals on average reproducing short and long duration negative and positive stimuli as lasting longer after experiencing social stress, t(41) = -3.55, p = .001, and t(41) = -4.12, p social stress. These findings are in line with some other studies of time distortion, and provide evidence for the interoceptive salience model of time perception. Implications for mechanisms of time distortion are discussed. © 2017 Society for Psychophysiological Research.

  6. Is the perception of time pressure a barrier to healthy eating and physical activity among women?

    Science.gov (United States)

    Welch, Nicky; McNaughton, Sarah A; Hunter, Wendy; Hume, Clare; Crawford, David

    2009-07-01

    To describe the proportion of women reporting time is a barrier to healthy eating and physical activity, the characteristics of these women and the perceived causes of time pressure, and to examine associations between perceptions of time as a barrier and consumption of fruit, vegetables and fast food, and physical activity. A cross-sectional survey of food intake, physical activity and perceived causes of time pressure. A randomly selected community sample. A sample of 1580 women self-reported their food intake and their perceptions of the causes of time pressure in relation to healthy eating. An additional 1521 women self-reported their leisure-time physical activity and their perceptions of the causes of time pressure in relation to physical activity. Time pressure was reported as a barrier to healthy eating by 41% of the women and as a barrier to physical activity by 73%. Those who reported time pressure as a barrier to healthy eating were significantly less likely to meet fruit, vegetable and physical activity recommendations, and more likely to eat fast food more frequently. Women reporting time pressure as a barrier to healthy eating and physical activity are less likely to meet recommendations than are women who do not see time pressure as a barrier. Further research is required to understand the perception of time pressure issues among women and devise strategies to improve women's food and physical activity behaviours.

  7. On-line sequential injection-capillary electrophoresis for near-real-time monitoring of extracellular lactate in cell culture flasks.

    Science.gov (United States)

    Alhusban, Ala A; Gaudry, Adam J; Breadmore, Michael C; Gueven, Nuri; Guijt, Rosanne M

    2014-01-03

    Cell culture has replaced many in vivo studies because of ethical and regulatory measures as well as the possibility of increased throughput. Analytical assays to determine (bio)chemical changes are often based on end-point measurements rather than on a series of sequential determinations. The purpose of this work is to develop an analytical system for monitoring cell culture based on sequential injection-capillary electrophoresis (SI-CE) with capacitively coupled contactless conductivity detection (C(4)D). The system was applied for monitoring lactate production, an important metabolic indicator, during mammalian cell culture. Using a background electrolyte consisting of 25mM tris(hydroxymethyl)aminomethane, 35mM cyclohexyl-2-aminoethanesulfonic acid with 0.02% poly(ethyleneimine) (PEI) at pH 8.65 and a multilayer polymer coated capillary, lactate could be resolved from other compounds present in media with relative standard deviations 0.07% for intraday electrophoretic mobility and an analysis time of less than 10min. Using the human embryonic kidney cell line HEK293, lactate concentrations in the cell culture medium were measured every 20min over 3 days, requiring only 8.73μL of sample per run. Combining simplicity, portability, automation, high sample throughput, low limits of detection, low sample consumption and the ability to up- and outscale, this new methodology represents a promising technique for near real-time monitoring of chemical changes in diverse cell culture applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. [Time perception, maternal tasks, and maternal role behavior among pregnant Japanese women].

    Science.gov (United States)

    Yamamoto, A

    1996-01-01

    The relationship of time perception, maternal tasks, and maternal role behavior was examined in 140 pregnant Japanese women with a short-term longitudinal design. A model developed by Rubin provided the conceptual framework for this research. The Time Perception Scale. Time Production Method, and the Prefatory Maternal Response measured the study variables. Study results revealed significant differences in duration of time, time production, maternal-fetal attachment, and maternal role behavior before and after quickening(fetal movement)occurred. Medium to strong positive relationships among time orientation, maternal-fetal attachment, gratification, and maternal role behavior were found before and after movement. After quickening, a weak relationship between time orientation and duration was found. After controlling maternal-fetal attachment and gratification in pregnancy and maternal role, orientation in time perception accounted for significant amounts of variance in maternal role behavior before and after fetal movement. Results show that the process of becoming a mother, which started before quickening, increased in magnitude after fetal movement. The function of fetal movement is important in developing motherhood. In the process of becoming a mother, cognitive, emotional, and behavioral aspects in becoming a mother are inseparable from each other. Future orientation of time perception contributes to development of maternal role behavior. Having a future orientation during pregnancy may indicate hope or positive expectation. Based on these findings, several recommendations were proposed: (a)to study further the general process of becoming a mother and the role of time perception in developing motherhood, (b)to disseminate information to the general public about the process in development of motherhood, (c)to construct theory to explain the process of becoming a mother, and(d)to conduct future research to clarify the construct of time perception and attachment.

  9. A unified model of time perception accounts for duration-based and beat-based timing mechanisms

    Directory of Open Access Journals (Sweden)

    Sundeep eTeki

    2012-01-01

    Full Text Available Accurate timing is an integral aspect of sensory and motor processes such as the perception of speech and music and the execution of skilled movement. Neuropsychological studies of time perception in patient groups and functional neuroimaging studies of timing in normal participants suggest common neural substrates for perceptual and motor timing. A timing system is implicated in core regions of the motor network such as the cerebellum, inferior olive, basal ganglia, pre-supplementary and supplementary motor area, pre-motor cortex and higher regions such as the prefrontal cortex.In this article, we assess how distinct parts of the timing system subserve different aspects of perceptual timing. We previously established brain bases for absolute, duration-based timing and relative, beat-based timing in the olivocerebellar and striato-thalamo-cortical circuits respectively (Teki et al., 2011. However, neurophysiological and neuroanatomical studies provide a basis to suggest that timing functions of these circuits may not be independent.Here, we propose a unified model of time perception based on coordinated activity in the core striatal and olivocerebellar networks that are interconnected with each other and the cerebral cortex th

  10. Examining the Relationship between Stress and Time Perception

    Science.gov (United States)

    2001-02-20

    felt as ifan experience or moment in time happened before ( Deja vu )? a Frequently a Sometimes o Rarely a Never 35. If you want to wake up in the...Point Enter 5 for Blur Enter 6 for Other 126 13. Have you ever felt as ifan experience or moment in time happened before ( Deja vu )? o Frequently...think about time? o Line o Arrow o Circle o Point o Blur o Other 13. Have you ever felt as if an experience or moment in time happened before ( Deja

  11. The time course of natural scene perception with reduced attention.

    Science.gov (United States)

    Groen, Iris I A; Ghebreab, Sennay; Lamme, Victor A F; Scholte, H Steven

    2016-02-01

    Attention is thought to impose an informational bottleneck on vision by selecting particular information from visual scenes for enhanced processing. Behavioral evidence suggests, however, that some scene information is extracted even when attention is directed elsewhere. Here, we investigated the neural correlates of this ability by examining how attention affects electrophysiological markers of scene perception. In two electro-encephalography (EEG) experiments, human subjects categorized real-world scenes as manmade or natural (full attention condition) or performed tasks on unrelated stimuli in the center or periphery of the scenes (reduced attention conditions). Scene processing was examined in two ways: traditional trial averaging was used to assess the presence of a categorical manmade/natural distinction in event-related potentials, whereas single-trial analyses assessed whether EEG activity was modulated by scene statistics that are diagnostic of naturalness of individual scenes. The results indicated that evoked activity up to 250 ms was unaffected by reduced attention, showing intact categorical differences between manmade and natural scenes and strong modulations of single-trial activity by scene statistics in all conditions. Thus initial processing of both categorical and individual scene information remained intact with reduced attention. Importantly, however, attention did have profound effects on later evoked activity; full attention on the scene resulted in prolonged manmade/natural differences, increased neural sensitivity to scene statistics, and enhanced scene memory. These results show that initial processing of real-world scene information is intact with diminished attention but that the depth of processing of this information does depend on attention. Copyright © 2016 the American Physiological Society.

  12. Action and Perception Are Temporally Coupled by a Common Mechanism That Leads to a Timing Misperception

    Science.gov (United States)

    Astefanoaei, Corina; Daye, Pierre M.; FitzGibbon, Edmond J.; Creanga, Dorina-Emilia; Rufa, Alessandra; Optican, Lance M.

    2015-01-01

    We move our eyes to explore the world, but visual areas determining where to look next (action) are different from those determining what we are seeing (perception). Whether, or how, action and perception are temporally coordinated is not known. The preparation time course of an action (e.g., a saccade) has been widely studied with the gap/overlap paradigm with temporal asynchronies (TA) between peripheral target onset and fixation point offset (gap, synchronous, or overlap). However, whether the subjects perceive the gap or overlap, and when they perceive it, has not been studied. We adapted the gap/overlap paradigm to study the temporal coupling of action and perception. Human subjects made saccades to targets with different TAs with respect to fixation point offset and reported whether they perceived the stimuli as separated by a gap or overlapped in time. Both saccadic and perceptual report reaction times changed in the same way as a function of TA. The TA dependencies of the time change for action and perception were very similar, suggesting a common neural substrate. Unexpectedly, in the perceptual task, subjects misperceived lights overlapping by less than ∼100 ms as separated in time (overlap seen as gap). We present an attention-perception model with a map of prominence in the superior colliculus that modulates the stimulus signal's effectiveness in the action and perception pathways. This common source of modulation determines how competition between stimuli is resolved, causes the TA dependence of action and perception to be the same, and causes the misperception. PMID:25632126

  13. Catch the wave! Time-window sequential analysis of alertness stimulation in individuals with profound intellectual and multiple disabilities

    NARCIS (Netherlands)

    Munde, V. S.; Vlaskamp, C.; Maes, B.; Ruijssenaars, A. J. J. M.

    BackgroundWhile optimally activities are provided at those moments when the individual with profound intellectual and multiple disabilities (PIMD) is focused on the environment' or alert', detailed information about the impact that the design and timing of the activity has on alertness is lacking.

  14. Relativity theory and time perception: single or multiple clocks?

    Science.gov (United States)

    Buhusi, Catalin V; Meck, Warren H

    2009-07-22

    Current theories of interval timing assume that humans and other animals time as if using a single, absolute stopwatch that can be stopped or reset on command. Here we evaluate the alternative view that psychological time is represented by multiple clocks, and that these clocks create separate temporal contexts by which duration is judged in a relative manner. Two predictions of the multiple-clock hypothesis were tested. First, that the multiple clocks can be manipulated (stopped and/or reset) independently. Second, that an event of a given physical duration would be perceived as having different durations in different temporal contexts, i.e., would be judged differently by each clock. Rats were trained to time three durations (e.g., 10, 30, and 90 s). When timing was interrupted by an unexpected gap in the signal, rats reset the clock used to time the "short" duration, stopped the "medium" duration clock, and continued to run the "long" duration clock. When the duration of the gap was manipulated, the rats reset these clocks in a hierarchical order, first the "short", then the "medium", and finally the "long" clock. Quantitative modeling assuming re-allocation of cognitive resources in proportion to the relative duration of the gap to the multiple, simultaneously timed event durations was used to account for the results. These results indicate that the three event durations were effectively timed by separate clocks operated independently, and that the same gap duration was judged relative to these three temporal contexts. Results suggest that the brain processes the duration of an event in a manner similar to Einstein's special relativity theory: A given time interval is registered differently by independent clocks dependent upon the context.

  15. Relativity theory and time perception: single or multiple clocks?

    Directory of Open Access Journals (Sweden)

    Catalin V Buhusi

    2009-07-01

    Full Text Available Current theories of interval timing assume that humans and other animals time as if using a single, absolute stopwatch that can be stopped or reset on command. Here we evaluate the alternative view that psychological time is represented by multiple clocks, and that these clocks create separate temporal contexts by which duration is judged in a relative manner. Two predictions of the multiple-clock hypothesis were tested. First, that the multiple clocks can be manipulated (stopped and/or reset independently. Second, that an event of a given physical duration would be perceived as having different durations in different temporal contexts, i.e., would be judged differently by each clock.Rats were trained to time three durations (e.g., 10, 30, and 90 s. When timing was interrupted by an unexpected gap in the signal, rats reset the clock used to time the "short" duration, stopped the "medium" duration clock, and continued to run the "long" duration clock. When the duration of the gap was manipulated, the rats reset these clocks in a hierarchical order, first the "short", then the "medium", and finally the "long" clock. Quantitative modeling assuming re-allocation of cognitive resources in proportion to the relative duration of the gap to the multiple, simultaneously timed event durations was used to account for the results.These results indicate that the three event durations were effectively timed by separate clocks operated independently, and that the same gap duration was judged relative to these three temporal contexts. Results suggest that the brain processes the duration of an event in a manner similar to Einstein's special relativity theory: A given time interval is registered differently by independent clocks dependent upon the context.

  16. Exploring the effects of adolescent perceptions of parenting in free time and gender on adolescent motivation in free time

    Science.gov (United States)

    Clifton E., Jr. Watts; Linda L. Caldwell

    2007-01-01

    This study examined how gender and perceptions of parenting related to adolescent motivation during free-time. The sample consisted of 377 ninthgraders from high schools in eastern Massachusetts. Significant gender differences were found for rules enacted, with females reporting more rules in place than males. When examining the relationship between parenting practices...

  17. Selective, Embedded, Just-In-Time Specialization (SEJITS): Portable Parallel Performance from Sequential, Productive, Embedded Domain-Specific Languages

    Science.gov (United States)

    2012-12-01

    approaches to speaker diarization become fast enough to obviate further research in offline approaches. (We have not yet investigated what components of the...Evans, Corinne Fredouille, G Friedland, and O Vinyals. Speaker diarization : A review of recent research. Accepted for publication in ”IEEE Transactions...implementation from [32]. (b) Diarizer application performance as a multiple of real time; “100×” means that 1 second of audio can be processed in 1/100

  18. Time-dependent quantum transport through an interacting quantum dot beyond sequential tunneling: second-order quantum rate equations

    International Nuclear Information System (INIS)

    Dong, B; Ding, G H; Lei, X L

    2015-01-01

    A general theoretical formulation for the effect of a strong on-site Coulomb interaction on the time-dependent electron transport through a quantum dot under the influence of arbitrary time-varying bias voltages and/or external fields is presented, based on slave bosons and the Keldysh nonequilibrium Green's function (GF) techniques. To avoid the difficulties of computing double-time GFs, we generalize the propagation scheme recently developed by Croy and Saalmann to combine the auxiliary-mode expansion with the celebrated Lacroix's decoupling approximation in dealing with the second-order correlated GFs and then establish a closed set of coupled equations of motion, called second-order quantum rate equations (SOQREs), for an exact description of transient dynamics of electron correlated tunneling. We verify that the stationary solution of our SOQREs is able to correctly describe the Kondo effect on a qualitative level. Moreover, a comparison with other methods, such as the second-order von Neumann approach and Hubbard-I approximation, is performed. As illustrations, we investigate the transient current behaviors in response to a step voltage pulse and a harmonic driving voltage, and linear admittance as well, in the cotunneling regime. (paper)

  19. Time Perception in Severe Traumatic Brain Injury Patients: A Study Comparing Different Methodologies

    Science.gov (United States)

    Mioni, G.; Mattalia, G.; Stablum, F.

    2013-01-01

    In this study, we investigated time perception in patients with traumatic brain injury (TBI). Fifteen TBI patients and 15 matched healthy controls participated in the study. Participants were tested with durations above and below 1s on three different temporal tasks that involved time reproduction, production, and discrimination tasks. Data…

  20. First-time mothers' breast-feeding maintenance: role of experiences and changes in maternal perceptions.

    Science.gov (United States)

    Schafer, Ellen J; Campo, Shelly; Colaizy, Tarah T; Mulder, Pamela J; Breheny, Patrick; Ashida, Sato

    2017-12-01

    Breast-feeding initiation rates have increased in the USA; however, maintenance of breast-feeding for recommended durations is low. The objective of the present study was to identify factors that may facilitate breast-feeding for longer durations among first-time mothers, including physiological and social experiences and changes in maternal perceptions. Survival analysis and linear regression methods were used to explore the relationship between experiences and breast-feeding duration, and the possible mediating effect of changes in maternal perceptions. Secondary data from the Infant Feeding Practices Study II, conducted in the USA between 2005 and 2007. Data from 762 first-time mothers who ever breast-fed were analysed. Experiencing trouble with baby's latch, problems with milk flow/supply and painful breast-feeding were significantly associated with breast-feeding duration (64, 26 and 36 % shorter duration, respectively). Meanwhile, positive changes in perception with respect to breast-feeding self-efficacy, opinion about infant feeding and belief about breast milk were associated with 16-27 % longer duration. Furthermore, changes in perception were observed to partially mediate the impact of physiological experiences on breast-feeding duration. Perceptions of breast-feeding self-efficacy, beliefs and opinions can change over time and are influenced by breast-feeding experiences. The combined effect of experience and perception plays a key role in influencing breast-feeding duration. Future research should explore interventions to maintain or improve these perceptions while accounting for physiological experiences to support breast-feeding for recommended durations among first-time mothers.

  1. Effects of fitness and self-confidence on time perception during exertion

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Full Text Available Aims: Human physical and psychological features influence perceptions of the environment during activity. If during exercise an individual over-estimates time, they may interpret this as spending longer than necessary under a potentially aversive state of exertion. This may in turn decrease one’s sense of exercise success and tendency to persevere with exercise. We tested if experimentally manipulating sense of exercise self-efficacy would affect time perception during standardised physical exertion. Method: Exercise Self-Efficacy (ESE of 18 -73 year olds (N=51 was measured before and after an exercise challenge of moderate intensity. Height, weight and body fat composition were measured before participants were randomly allocated to one of three groups. After a 4-minute treadmill fitness test, participants were presented with either bogus feedback about their performance (positive or negative or no feedback (control. Before and during exercise, participants estimated a prescribed 2-minute time interval. Ratings of perceived exertion were also measured periodically. Results: Feedback on performance had no significant effect on time perception, even when controlling for individual exertion level. Reported ESE was also unaffected by whether someone received positive, negative or no feedback. Age was again found to be significantly correlated with VO2max, r(51 = .62, p < .001, but in contrast to prior findings, estimates of general fitness such as VO2max, BMI and waist circumference were unrelated to changes in time perception due to exertion. Conclusions: These findings failed to support prior findings and anecdotal evidence suggesting that exertion might alter one’s perception of time. We also failed to find any support for effects on ESE when participants were given explicit performance feedback. Finally, participants’ physical characteristics appear to be unrelated to time perception whilst exercising at moderate intensity.

  2. Philosophy in contemporary time: Relevance vs. Public perception ...

    African Journals Online (AJOL)

    What is the relevance of philosophy in this contemporary time? Philosophy is viewed by many people as an irrelevant discipline- one of no social and/or practical significance. It is sometimes seen also as an abstract and drab enterprise fit only for the intellectuals. Overtime also, philosophy has come to be perceived as ...

  3. The hunt for the perfect discounting function and a reckoning of time perception.

    Science.gov (United States)

    Namboodiri, Vijay Mk; Hussain Shuler, Marshall G

    2016-10-01

    Making decisions that factor the cost of time is fundamental to survival. Yet, while it is readily appreciated that our perception of time is intimately involved in this process, theories regarding intertemporal decision-making and theories regarding time perception are treated, largely, independently. Even within these respective domains, models providing good fits to data fail to provide insight as to why, from a normative sense, those fits should take their apparent form. Conversely, normative models that proffer a rationalization for why an agent should weigh options in a particular way, or to perceive time in a particular way, fail to account for the full body of well-established experimental evidence. Here we review select, yet key advances in our understanding, identifying conceptual breakthroughs in the fields of intertemporal decision-making and in time perception, as well as their limits and failings in the face of hard-won experimental observation. On this background of accrued knowledge, a new conception unifying the domains of decision-making and time perception is put forward (Training-Integrated Maximization of Reinforcement Rate, TIMERR) to provide a better fit to observations and a more parsimonious reckoning of why we make choices, and thereby perceive time, the way we do. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Analysis of bus passenger comfort perception based on passenger load factor and in-vehicle time.

    Science.gov (United States)

    Shen, Xianghao; Feng, Shumin; Li, Zhenning; Hu, Baoyu

    2016-01-01

    Although bus comfort is a crucial indicator of service quality, existing studies tend to focus on passenger load and ignore in-vehicle time, which can also affect passengers' comfort perception. Therefore, by conducting surveys, this study examines passengers' comfort perception while accounting for both factors. Then, using the survey data, it performs a two-way analysis of variance and shows that both in-vehicle time and passenger load significantly affect passenger comfort. Then, a bus comfort model is proposed to evaluate comfort level, followed by a sensitivity analysis. The method introduced in this study has theoretical implications for bus operators attempting to improve bus service quality.

  5. Uncertainty Expressions in Accounting Standards: is there any effect of time in the differences of perception?

    Directory of Open Access Journals (Sweden)

    Rodrigo Fernandes Malaquias

    2017-04-01

    Full Text Available This paper examines whether differences in the perception of uncertainty expressions persist over time. The empirical analysis of this question involved two approaches: quantitative (with tests to compare means, medians, regression analysis with ordinary least squares and quantile regression, and qualitative, with interviews. Principal findings are that the differences in the perceptions of participants with respect to uncertainty expressions were not statistically significant, which differs from the findings reported in previous studies. This may be indicative of a tendency toward elimination of potential differences in the interpretation of accounting standards over time.

  6. Temporal regularity of the environment drives time perception

    OpenAIRE

    van Rijn, H; Rhodes, D; Di Luca, M

    2016-01-01

    It’s reasonable to assume that a regularly paced sequence should be perceived as regular, but here we show that perceived regularity depends on the context in which the sequence is embedded. We presented one group of participants with perceptually regularly paced sequences, and another group of participants with mostly irregularly paced sequences (75% irregular, 25% regular). The timing of the final stimulus in each sequence could be var- ied. In one experiment, we asked whether the last stim...

  7. Opposite Distortions in Interval Timing Perception for Visual and Auditory Stimuli with Temporal Modulations.

    Science.gov (United States)

    Yuasa, Kenichi; Yotsumoto, Yuko

    2015-01-01

    When an object is presented visually and moves or flickers, the perception of its duration tends to be overestimated. Such an overestimation is called time dilation. Perceived time can also be distorted when a stimulus is presented aurally as an auditory flutter, but the mechanisms and their relationship to visual processing remains unclear. In the present study, we measured interval timing perception while modulating the temporal characteristics of visual and auditory stimuli, and investigated whether the interval times of visually and aurally presented objects shared a common mechanism. In these experiments, participants compared the durations of flickering or fluttering stimuli to standard stimuli, which were presented continuously. Perceived durations for auditory flutters were underestimated, while perceived durations of visual flickers were overestimated. When auditory flutters and visual flickers were presented simultaneously, these distortion effects were cancelled out. When auditory flutters were presented with a constantly presented visual stimulus, the interval timing perception of the visual stimulus was affected by the auditory flutters. These results indicate that interval timing perception is governed by independent mechanisms for visual and auditory processing, and that there are some interactions between the two processing systems.

  8. Efficient constraint-based Sequential Pattern Mining (SPM algorithm to understand customers’ buying behaviour from time stamp-based sequence dataset

    Directory of Open Access Journals (Sweden)

    Niti Ashish Kumar Desai

    2015-12-01

    Full Text Available Business Strategies are formulated based on an understanding of customer needs. This requires development of a strategy to understand customer behaviour and buying patterns, both current and future. This involves understanding, first how an organization currently understands customer needs and second predicting future trends to drive growth. This article focuses on purchase trend of customer, where timing of purchase is more important than association of item to be purchased, and which can be found out with Sequential Pattern Mining (SPM methods. Conventional SPM algorithms worked purely on frequency identifying patterns that were more frequent but suffering from challenges like generation of huge number of uninteresting patterns, lack of user’s interested patterns, rare item problem, etc. Article attempts a solution through development of a SPM algorithm based on various constraints like Gap, Compactness, Item, Recency, Profitability and Length along with Frequency constraint. Incorporation of six additional constraints is as well to ensure that all patterns are recently active (Recency, active for certain time span (Compactness, profitable and indicative of next timeline for purchase (Length―Item―Gap. The article also attempts to throw light on how proposed Constraint-based Prefix Span algorithm is helpful to understand buying behaviour of customer which is in formative stage.

  9. Discrimination between sequential and simultaneous virtual channels with electrical hearing

    OpenAIRE

    Landsberger, David; Galvin, John J.

    2011-01-01

    In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation mode...

  10. Time perception, impulsivity, emotionality, and personality in self-harming borderline personality disorder patients.

    Science.gov (United States)

    Berlin, Heather A; Rolls, Edmund T

    2004-08-01

    To investigate how time perception may contribute to the symptoms of self-harming Borderline Personality Disorder (BPD) patients, 19 self-harming BPD inpatients and 39 normal controls were given measures of time perception, impulsivity, personality, emotion, and BPD characteristics. A test sensitive to orbitofrontal cortex (OFC) function ("Frontal" Behavior Questionnaire) was also administered, as the OFC has been associated with impulsivity and time perception. BPD patients produced less time than controls, and this correlated with impulsiveness and other characteristics commonly associated with BPD. BPD patients were also less conscientious, extraverted, and open to experience, as well as more impulsive (self-report and behaviorally), emotional, neurotic, and reported more BPD characteristics, compared to controls. The results suggest that some of these core characteristics of BPD may be on a continuum with the normal population and, impulsivity in particular, may be related to time perception deficits (i.e., a faster subjective sense of time). Finally, BPD patients scored higher on the Frontal Behavior Questionnaire, suggesting that some symptoms of the BPD syndrome may be related to problems associated with the OFC. A control spatial working memory task (SWM) revealed that SWM deficits could not explain any of the BPD patients' poor performance. While impulsivity was correlated with time perception across all participants, emotionality, introversion, and lack of openness to experience were not. This suggests that different symptoms of the borderline personality syndrome may be separable, and therefore, related to different cognitive deficits, and potentially to different brain systems. This may have important implications for treatment strategies for BPD.

  11. Nurses' perception of time availability in patient communication in Hong Kong.

    Science.gov (United States)

    Chan, Engle A; Jones, Aled; Fung, Sylvia; Wu, Sui Chu

    2012-04-01

    To explore nurses' perceptions of their patient communication in practice and to identify their ways of communicating. Nurse theorists and clinicians are aware of the importance of nurse-patient communication in providing patient-centred care. However, barriers remain that prevent nurses from implementing quality/effective communication, and time is often viewed as a critical variable. Continuous emphasis on efficiency contravenes patient-centred care, warranting a re-examination of nurses' perception of time in nurse-patient communication. Focus group interviews were adopted. Thirty-nine registered nurses participated. Interviews were tape-recorded, transcribed and translated, and data were analysed using thematic analysis to identify codes, categories and themes/patterns. Three themes were identified regarding nurses' perception of communication with time: (1) Patterns of communication. (2) Routine scheduled communication vs. meeting individuals' needs. (3) Saving time through communication. Patterns of communication, based on participants' criteria such as the purpose, who initiated it, the nature of communication, expectation to perform, therapeutic value and relation with time were explicated. By integrating communication into routines as intended actions, nurses demonstrate that communication and relationship building with patients take no extra time. Good communication and good relationships help nurses save time. Nurses' communication behaviour is closely related to their perception of communication. This study suggests the need for a paradigm shift in thinking about communication as requiring time. Additionally, nurses should recognise the value of short, iterative interaction and chit-chat as quality communication for knowing their patients and providing patient-centred care. Nurses should think beyond time in the discourse of effective nurse-patient communication, as it often relates to manpower. An understanding of how nurses perceive their time

  12. Two-dimensional Shear Wave Elastography on Conventional Ultrasound Scanners with Time Aligned Sequential Tracking (TAST) and Comb-push Ultrasound Shear Elastography (CUSE)

    Science.gov (United States)

    Song, Pengfei; Macdonald, Michael C.; Behler, Russell H.; Lanning, Justin D.; Wang, Michael H.; Urban, Matthew W.; Manduca, Armando; Zhao, Heng; Callstrom, Matthew R.; Alizad, Azra; Greenleaf, James F.; Chen, Shigao

    2014-01-01

    Two-dimensional (2D) shear wave elastography presents 2D quantitative shear elasticity maps of tissue, which are clinically useful for both focal lesion detection and diffuse disease diagnosis. Realization of 2D shear wave elastography on conventional ultrasound scanners, however, is challenging due to the low tracking pulse-repetition-frequency (PRF) of these systems. While some clinical and research platforms support software beamforming and plane wave imaging with high PRF, the majority of current clinical ultrasound systems do not have the software beamforming capability, which presents a critical challenge for translating the 2D shear wave elastography technique from laboratory to clinical scanners. To address this challenge, this paper presents a Time Aligned Sequential Tracking (TAST) method for shear wave tracking on conventional ultrasound scanners. TAST takes advantage of the parallel beamforming capability of conventional systems and realizes high PRF shear wave tracking by sequentially firing tracking vectors and aligning shear wave data in the temporal direction. The Comb-push Ultrasound Shear Elastography (CUSE) technique was used to simultaneously produce multiple shear wave sources within the field-of-view (FOV) to enhance shear wave signal-to-noise-ratio (SNR) and facilitate robust reconstructions of 2D elasticity maps. TAST and CUSE were realized on a conventional ultrasound scanner (the General Electric LOGIQ E9). A phantom study showed that the shear wave speed measurements from the LOGIQ E9 were in good agreement to the values measured from other 2D shear wave imaging technologies. An inclusion phantom study showed that the LOGIQ E9 had comparable performance to the Aixplorer (Supersonic Imagine) in terms of bias and precision in measuring different sized inclusions. Finally, in vivo case analysis of a breast with a malignant mass, and a liver from a healthy subject demonstrated the feasibility of using the LOGIQ E9 for in vivo 2D shear wave

  13. Attention Switching during Scene Perception: How Goals Influence the Time Course of Eye Movements across Advertisements

    Science.gov (United States)

    Wedel, Michel; Pieters, Rik; Liechty, John

    2008-01-01

    Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a…

  14. Bullying Behavior, Parents' Work Hours and Early Adolescents' Perceptions of Time Spent with Parents

    Science.gov (United States)

    Christie-Mizell, C. Andre; Keil, Jacqueline M.; Laske, Mary Therese; Stewart, Jennifer

    2011-01-01

    This research investigates the relationships among bullying behavior, mother's and father's work hours, and early adolescents' perceptions of whether they spend sufficient time with their parents. In cross-sectional models, we find maternal work hours are modestly associated with increases in bullying behavior. However, in more rigorous change…

  15. On the relation between texture perception and fundamental mechanical parameters for liquids and time dependent solids

    NARCIS (Netherlands)

    Vliet, van T.

    2002-01-01

    Abstract Aspects of the relationship between texture perception in the mouth and fundamental mechanical parameters for liquids and time dependent solids are discussed. The emphasis is on the physical side of the relation. The importance is stressed of the incorporation of a thorough knowledge of

  16. Time Perception: Modality and Duration Effects in Attention-Deficit/Hyperactivity Disorder (ADHD)

    Science.gov (United States)

    Toplak, Maggie E.; Tannock, Rosemary

    2005-01-01

    Time perception performance was systematically investigated in adolescents with and without attention-deficit/hyperactivity disorder (ADHD). Specifically, the effects of manipulating modality (auditory and visual) and length of duration (200 and 1000 ms) were examined. Forty-six adolescents with ADHD and 44 controls were administered four duration…

  17. A general theory of intertemporal decision-making and the perception of time

    Directory of Open Access Journals (Sweden)

    Vijay Mohan eK Namboodiri

    2014-02-01

    Full Text Available Animals and humans make decisions based on their expected outcomes. Since relevant outcomes are often delayed, perceiving delays and choosing between earlier versus later rewards (intertemporal decision-making is an essential component of animal behavior. The myriad observations made in experiments studying intertemporal decision-making and time perception have not yet been rationalized within a single theory. Here we present a theory—Training-Integrated Maximized Estimation of Reinforcement Rate (TIMERR—that explains a wide variety of behavioral observations made in intertemporal decision-making and the perception of time. Our theory postulates that animals make intertemporal choices to optimize expected reward rates over a limited temporal window which includes a past integration interval—over which experienced reward rate is estimated—as well as the expected delay to future reward. Using this theory, we derive mathematical expressions for both the subjective value of a delayed reward and the subjective representation of the delay. A unique contribution of our work is in finding that the past integration interval directly determines the steepness of temporal discounting and the nonlinearity of time perception. In so doing, our theory provides a single framework to understand both intertemporal decision-making and time perception.

  18. Teachers' Perceptions of Full- and Part-Time Nurses at School

    Science.gov (United States)

    Biag, Manuelito; Srivastava, Ashini; Landau, Melinda; Rodriguez, Eunice

    2015-01-01

    Teachers and school nurses partner together to help ensure students stay healthy and engaged in school. The purpose of this study is to generate a deeper understanding of teachers' perceptions on the benefits and challenges of working with full- or part-time school nurses. We conducted a qualitative analysis of open-ended survey responses from 129…

  19. A general theory of intertemporal decision-making and the perception of time.

    Science.gov (United States)

    Namboodiri, Vijay M K; Mihalas, Stefan; Marton, Tanya M; Hussain Shuler, Marshall G

    2014-01-01

    Animals and humans make decisions based on their expected outcomes. Since relevant outcomes are often delayed, perceiving delays and choosing between earlier vs. later rewards (intertemporal decision-making) is an essential component of animal behavior. The myriad observations made in experiments studying intertemporal decision-making and time perception have not yet been rationalized within a single theory. Here we present a theory-Training-Integrated Maximized Estimation of Reinforcement Rate (TIMERR)-that explains a wide variety of behavioral observations made in intertemporal decision-making and the perception of time. Our theory postulates that animals make intertemporal choices to optimize expected reward rates over a limited temporal window which includes a past integration interval-over which experienced reward rate is estimated-as well as the expected delay to future reward. Using this theory, we derive mathematical expressions for both the subjective value of a delayed reward and the subjective representation of the delay. A unique contribution of our work is in finding that the past integration interval directly determines the steepness of temporal discounting and the non-linearity of time perception. In so doing, our theory provides a single framework to understand both intertemporal decision-making and time perception.

  20. A sequential logic circuit for coincidences randomly distributed in 'time' and 'duration', with selection and total sampling

    International Nuclear Information System (INIS)

    Carnet, Bernard; Delhumeau, Michel

    1971-06-01

    The principles of binary analysis applied to the investigation of sequential circuits were used to design a two way coincidence circuit whose input may be, random or periodic variables of constant or variable duration. The output signal strictly reproduces the characteristics of the input signal triggering the coincidence. A coincidence between input signals does not produce any output signal if one of the signals has already triggered the output signal. The characteristics of the output signal in relation to those of the input signal are: minimum time jitter, excellent duration reproducibility and maximum efficiency. Some rules are given for achieving these results. The symmetry, transitivity and non-transitivity characteristics of the edges on the primitive graph are analyzed and lead to some rules for positioning the states on a secondary graph. It is from this graph that the equations of the circuits can be calculated. The development of the circuit and its dynamic testing are discussed. For this testing, the functioning of the circuit is simulated by feeding into the input randomly generated signals

  1. The effects of quantity and depth of processing on children's time perception.

    Science.gov (United States)

    Arlin, M

    1986-08-01

    Two experiments were conducted to investigate the effects of quantity and depth of processing on children's time perception. These experiments tested the appropriateness of two adult time-perception models (attentional and storage size) for younger ages. Children were given stimulus sets of equal time which varied by level of processing (deep/shallow) and quantity (list length). In the first experiment, 28 children in Grade 6 reproduced presentation times of various quantities of pictures under deep (living/nonliving categorization) or shallow (repeating label) conditions. Students also compared pairs of durations. In the second experiment, 128 children in Grades K, 2, 4, and 6 reproduced presentation times under similar conditions with three or six pictures and with deep or shallow processing requirements. Deep processing led to decreased estimation of time. Higher quantity led to increased estimation of time. Comparative judgments were influenced by quantity. The interaction between age and depth of processing was significant. Older children were more affected by depth differences than were younger children. Results were interpreted as supporting different aspects of each adult model as explanations of children's time perception. The processing effect supported the attentional model and the quantity effect supported the storage size model.

  2. “Childhood overweight and obesity: maternal perceptions of the time for engaging in child weight management”

    OpenAIRE

    Warschburger, Petra; Kröller, Katja

    2012-01-01

    Abstract Background There is an increasing awareness of the impact of parental risk perception on the weight course of the child and the parent’s readiness to engage in preventive efforts, but only less is known about factors related to the parental perception of the right time for the implementation of preventive activities. The aim of this study was to examine parental perceptions of the appropriate time to engage in child weight management strategies, and the factors associated with differ...

  3. Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research.

    Directory of Open Access Journals (Sweden)

    Liam D Harper

    Full Text Available Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63% either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50% and do not (50% account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk

  4. Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research.

    Science.gov (United States)

    Harper, Liam D; Fothergill, Melissa; West, Daniel J; Stevenson, Emma; Russell, Mark

    2016-01-01

    Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery

  5. Job quality of short-time workers and perception and support from their managers

    OpenAIRE

    坂爪, 洋美

    2017-01-01

    The purpose of this study was to clarify the relationship between the characteristics of job quality that short-time workers occupied and the managers’ perception and support whose member has used short-time working hour system. A total of 559 first-line managers who has a member using short-time working hour system completed a web-based survey assessing job quality of short-time workers , the risk of using short-timeworking hour system, career perspective of short-time workers, and the suppo...

  6. Obliteration dynamics in cerebral arteriovenous malformations after cyberknife radiosurgery: quantification with sequential nidus volumetry and 3-tesla 3-dimensional time-of-flight magnetic resonance angiography.

    Science.gov (United States)

    Wowra, Berndt; Muacevic, Alexander; Tonn, Jörg-Christian; Schoenberg, Stefan O; Reiser, Maximilian; Herrmann, Karin A

    2009-02-01

    To investigate the time-dependent obliteration of cerebral arteriovenous malformations (cAVM) after CyberKnife radiosurgery (CKRS) (Accuray, Inc., Sunnyvale, CA) by means of sequential 3-T, 3-dimensional (3D), time-of-flight (TOF) magnetic resonance angiography (MRA), and volumetry of the arteriovenous malformation (AVM) nidus. In this prospective study, 3D TOF MRA was performed on 20 patients with cAVMs treated by single-fraction CKRS. Three-dimensional TOF MRA was performed on a 3-T, 32-channel magnetic resonance scanner (Magnetom TIM Trio; Siemens Medical Solutions, Erlangen, Germany) with isotropic voxel size at a spatial resolution of 0.6 x 0.6 x 0.6 mm3. The time-dependent relative decay of the transnidal blood flow evidenced by 3D TOF MRA was referred to as "obliteration dynamics." Volumetry of the nidus size was performed with OsiriX imaging software (OsiriX Foundation, Geneva, Switzerland). All patients had 3 to 4 follow-up examinations at 3- to 6-month intervals over a minimum follow-up period of 9 months. Subtotal obliteration was determined if the residual nidus volume was 5% or less of the initial nidus volume. Stata/IC software (Version 10.0; Stata Corp., College Station, TX) was used for statistical analysis and to identify potential factors of AVM obliteration. Regarding their clinical status, case history, and pretreatments, the participants of this study represent difficult-to-treat cAVM patients. The median nidus volume was 1.8 mL (range, 0.4-12.5 mL); the median minimum dose prescribed to the nidus was 22 Gy (range, 16-24 Gy) delivered to the 67% isodose line (range, 55-80%). CKRS was well tolerated, with complications in 2 patients. No further hemorrhages occurred after RS, except 1 small and clinically inapparent incident. The median follow-up period after RS was 25.0 months (range, 11.7-36.8 months). After RS, a statistically significant obliteration was observed in all patients. However, the obliteration dynamics of the cAVMs showed a

  7. Timing in audiovisual speech perception: A mini review and new psychophysical data.

    Science.gov (United States)

    Venezia, Jonathan H; Thurman, Steven M; Matchin, William; George, Sahara E; Hickok, Gregory

    2016-02-01

    Recent influential models of audiovisual speech perception suggest that visual speech aids perception by generating predictions about the identity of upcoming speech sounds. These models place stock in the assumption that visual speech leads auditory speech in time. However, it is unclear whether and to what extent temporally-leading visual speech information contributes to perception. Previous studies exploring audiovisual-speech timing have relied upon psychophysical procedures that require artificial manipulation of cross-modal alignment or stimulus duration. We introduce a classification procedure that tracks perceptually relevant visual speech information in time without requiring such manipulations. Participants were shown videos of a McGurk syllable (auditory /apa/ + visual /aka/ = perceptual /ata/) and asked to perform phoneme identification (/apa/ yes-no). The mouth region of the visual stimulus was overlaid with a dynamic transparency mask that obscured visual speech in some frames but not others randomly across trials. Variability in participants' responses (~35 % identification of /apa/ compared to ~5 % in the absence of the masker) served as the basis for classification analysis. The outcome was a high resolution spatiotemporal map of perceptually relevant visual features. We produced these maps for McGurk stimuli at different audiovisual temporal offsets (natural timing, 50-ms visual lead, and 100-ms visual lead). Briefly, temporally-leading (~130 ms) visual information did influence auditory perception. Moreover, several visual features influenced perception of a single speech sound, with the relative influence of each feature depending on both its temporal relation to the auditory signal and its informational content.

  8. Timing in Audiovisual Speech Perception: A Mini Review and New Psychophysical Data

    Science.gov (United States)

    Venezia, Jonathan H.; Thurman, Steven M.; Matchin, William; George, Sahara E.; Hickok, Gregory

    2015-01-01

    Recent influential models of audiovisual speech perception suggest that visual speech aids perception by generating predictions about the identity of upcoming speech sounds. These models place stock in the assumption that visual speech leads auditory speech in time. However, it is unclear whether and to what extent temporally-leading visual speech information contributes to perception. Previous studies exploring audiovisual-speech timing have relied upon psychophysical procedures that require artificial manipulation of cross-modal alignment or stimulus duration. We introduce a classification procedure that tracks perceptually-relevant visual speech information in time without requiring such manipulations. Participants were shown videos of a McGurk syllable (auditory /apa/ + visual /aka/ = perceptual /ata/) and asked to perform phoneme identification (/apa/ yes-no). The mouth region of the visual stimulus was overlaid with a dynamic transparency mask that obscured visual speech in some frames but not others randomly across trials. Variability in participants' responses (∼35% identification of /apa/ compared to ∼5% in the absence of the masker) served as the basis for classification analysis. The outcome was a high resolution spatiotemporal map of perceptually-relevant visual features. We produced these maps for McGurk stimuli at different audiovisual temporal offsets (natural timing, 50-ms visual lead, and 100-ms visual lead). Briefly, temporally-leading (∼130 ms) visual information did influence auditory perception. Moreover, several visual features influenced perception of a single speech sound, with the relative influence of each feature depending on both its temporal relation to the auditory signal and its informational content. PMID:26669309

  9. EEG correlates of cognitive time scales in the Necker-Zeno model for bistable perception.

    Science.gov (United States)

    Kornmeier, J; Friedel, E; Wittmann, M; Atmanspacher, H

    2017-08-01

    The Necker-Zeno model of bistable perception provides a formal relation between the average duration of meta-stable percepts (dwell times T) of ambiguous figures and two other basic time scales (t 0 , ΔT) underlying cognitive processing. The model predicts that dwell times T covary with t 0 , ΔT or both. We tested this prediction by exploiting that observers, in particular experienced meditators, can volitionally control dwell times T. Meditators and non-meditators observed bistable Necker cubes either passively or tried to hold their current percept. The latencies of a centro-parietal event-related potential (CPP) were recorded as a physiological correlate of t 0 . Dwell times T and the CPP latencies, correlated with t 0 , differed between conditions and observer groups, while ΔT remained constant in the range predicted by the model. The covariation of CPP latencies and dwell times, as well as their quadratic functional dependence extends previous psychophysical confirmation of the Necker-Zeno model to psychophysiological measures. Copyright © 2017. Published by Elsevier Inc.

  10. Evaluation of ceiling lifts: transfer time, patient comfort and staff perceptions.

    Science.gov (United States)

    Alamgir, Hasanat; Li, Olivia Wei; Yu, Shicheng; Gorman, Erin; Fast, Catherine; Kidd, Catherine

    2009-09-01

    Mechanical lifting devices have been developed to reduce healthcare worker injuries related to patient handling. The purpose of this study was to evaluate ceiling lifts in comparison to floor lifts based on transfer time, patient comfort and staff perceptions in three long-term care facilities with varying ceiling lift coverage. The time required to transfer or reposition patients along with patient comfort levels were recorded for 119 transfers. Transfers performed with ceiling lifts required on average less time (bed to chair transfers: 156.9 seconds for ceiling lift, 273.6 seconds for floor lift) and were found to be more comfortable for patients. In the three facilities, 143 healthcare workers were surveyed on their perceptions of patient handling tasks and equipment. For both transferring and repositioning tasks, staff preferred to use ceiling lifts and also found them to be less physically demanding. Further investigation is needed on repositioning tasks to ensure safe practice.

  11. Adaptive sequential controller

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawi, Mohamed A. (Renton, WA); Xing, Jian (Seattle, WA); Butler, Nicholas G. (Newberg, OR); Rodriguez, Alonso (Pasadena, CA)

    1994-01-01

    An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

  12. Adaptive sequential controller

    Science.gov (United States)

    El-Sharkawi, Mohamed A.; Xing, Jian; Butler, Nicholas G.; Rodriguez, Alonso

    1994-01-01

    An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

  13. Multi-agent sequential hypothesis testing

    KAUST Repository

    Kim, Kwang-Ki K.

    2014-12-15

    This paper considers multi-agent sequential hypothesis testing and presents a framework for strategic learning in sequential games with explicit consideration of both temporal and spatial coordination. The associated Bayes risk functions explicitly incorporate costs of taking private/public measurements, costs of time-difference and disagreement in actions of agents, and costs of false declaration/choices in the sequential hypothesis testing. The corresponding sequential decision processes have well-defined value functions with respect to (a) the belief states for the case of conditional independent private noisy measurements that are also assumed to be independent identically distributed over time, and (b) the information states for the case of correlated private noisy measurements. A sequential investment game of strategic coordination and delay is also discussed as an application of the proposed strategic learning rules.

  14. A neuroeconomic theory of rational addiction and nonlinear time-perception.

    Science.gov (United States)

    Takahashi, Taiki

    2011-01-01

    Neuroeconomic conditions for "rational addiction" (Becker & Murphy 1988) have been unknown. This paper derived the conditions for "rational addiction" by utilizing a nonlinear time-perception theory of "hyperbolic" discounting, which is mathematically equivalent to the q-exponential intertemporal choice model based on Tsallis' statistics. It is shown that (i) Arrow-Pratt measure for temporal cognition corresponds to the degree of irrationality (i.e., Prelec's "decreasing impatience" parameter of temporal discounting) and (ii) rationality in addicts is controlled by a nondimensionalization parameter of the logarithmic time-perception function. Furthermore, the present theory illustrates the possibility that addictive drugs increase impulsivity via dopaminergic neuroadaptation without increasing irrationality. Future directions in the application of the model to studies in neuroeconomics are discussed.

  15. Who acts more like a game theorist? Group and indivdual play in a sequential market game and the effect of the time horizon

    NARCIS (Netherlands)

    Müller, W.; Tan, F.

    2013-01-01

    Previous experimental results on one-shot sequential two-player games show that group decisions are closer to the subgame-perfect Nash equilibrium than individual decisions. We extend the analysis of intergroup versus interindividual decision-making by running both one-shot and repeated sessions of

  16. Discrimination between sequential and simultaneous virtual channels with electrical hearing.

    Science.gov (United States)

    Landsberger, David; Galvin, John J

    2011-09-01

    In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation modes. For sequential VCs, the interpulse interval (IPI) varied between 0.0 and 1.8 ms. All stimuli were presented at comfortably loud, loudness-balanced levels at a 250 pulse per second per electrode (ppse) stimulation rate. On average, CI subjects were able to reliably discriminate between sequential and simultaneous VCs. While there was no significant effect of IPI or stimulation mode on VC discrimination, some subjects exhibited better VC discrimination with BP + 1 stimulation. Subjects' discrimination between sequential and simultaneous VCs was correlated with electrode discrimination, suggesting that spatial selectivity may influence perception of sequential VCs. To maintain equal loudness, sequential VC amplitudes were nearly double those of simultaneous VCs, presumably resulting in a broader spread of excitation. These results suggest that perceptual differences between simultaneous and sequential VCs might be explained by differences in the spread of excitation. © 2011 Acoustical Society of America

  17. Endogenous sequential cortical activity evoked by visual stimuli.

    Science.gov (United States)

    Carrillo-Reid, Luis; Miller, Jae-Eun Kang; Hamm, Jordan P; Jackson, Jesse; Yuste, Rafael

    2015-06-10

    Although the functional properties of individual neurons in primary visual cortex have been studied intensely, little is known about how neuronal groups could encode changing visual stimuli using temporal activity patterns. To explore this, we used in vivo two-photon calcium imaging to record the activity of neuronal populations in primary visual cortex of awake mice in the presence and absence of visual stimulation. Multidimensional analysis of the network activity allowed us to identify neuronal ensembles defined as groups of cells firing in synchrony. These synchronous groups of neurons were themselves activated in sequential temporal patterns, which repeated at much higher proportions than chance and were triggered by specific visual stimuli such as natural visual scenes. Interestingly, sequential patterns were also present in recordings of spontaneous activity without any sensory stimulation and were accompanied by precise firing sequences at the single-cell level. Moreover, intrinsic dynamics could be used to predict the occurrence of future neuronal ensembles. Our data demonstrate that visual stimuli recruit similar sequential patterns to the ones observed spontaneously, consistent with the hypothesis that already existing Hebbian cell assemblies firing in predefined temporal sequences could be the microcircuit substrate that encodes visual percepts changing in time. Copyright © 2015 Carrillo-Reid et al.

  18. The real-time link between person perception and action: brain potential evidence for dynamic continuity.

    Science.gov (United States)

    Freeman, Jonathan B; Ambady, Nalini; Midgley, Katherine J; Holcomb, Phillip J

    2011-01-01

    Using event-related potentials, we investigated how the brain extracts information from another's face and translates it into relevant action in real time. In Study 1, participants made between-hand sex categorizations of sex-typical and sex-atypical faces. Sex-atypical faces evoked negativity between 250 and 550 ms (N300/N400 effects), reflecting the integration of accumulating sex-category knowledge into a coherent sex-category interpretation. Additionally, the lateralized readiness potential revealed that the motor cortex began preparing for a correct hand response while social category knowledge was still gradually evolving in parallel. In Study 2, participants made between-hand eye-color categorizations as part of go/no-go trials that were contingent on a target's sex. On no-go trials, although the hand did not actually move, information about eye color partially prepared the motor cortex to move the hand before perception of sex had finalized. Together, these findings demonstrate the dynamic continuity between person perception and action, such that ongoing results from face processing are immediately and continuously cascaded into the motor system over time. The preparation of action begins based on tentative perceptions of another's face before perceivers have finished interpreting what they just saw. © 2010 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business

  19. Self-motion perception: assessment by real-time computer-generated animations

    Science.gov (United States)

    Parker, D. E.; Phillips, J. O.

    2001-01-01

    We report a new procedure for assessing complex self-motion perception. In three experiments, subjects manipulated a 6 degree-of-freedom magnetic-field tracker which controlled the motion of a virtual avatar so that its motion corresponded to the subjects' perceived self-motion. The real-time animation created by this procedure was stored using a virtual video recorder for subsequent analysis. Combined real and illusory self-motion and vestibulo-ocular reflex eye movements were evoked by cross-coupled angular accelerations produced by roll and pitch head movements during passive yaw rotation in a chair. Contrary to previous reports, illusory self-motion did not correspond to expectations based on semicircular canal stimulation. Illusory pitch head-motion directions were as predicted for only 37% of trials; whereas, slow-phase eye movements were in the predicted direction for 98% of the trials. The real-time computer-generated animations procedure permits use of naive, untrained subjects who lack a vocabulary for reporting motion perception and is applicable to basic self-motion perception studies, evaluation of motion simulators, assessment of balance disorders and so on.

  20. Timescale- and Sensory Modality-Dependency of the Central Tendency of Time Perception.

    Science.gov (United States)

    Murai, Yuki; Yotsumoto, Yuko

    2016-01-01

    When individuals are asked to reproduce intervals of stimuli that are intermixedly presented at various times, longer intervals are often underestimated and shorter intervals overestimated. This phenomenon may be attributed to the central tendency of time perception, and suggests that our brain optimally encodes a stimulus interval based on current stimulus input and prior knowledge of the distribution of stimulus intervals. Two distinct systems are thought to be recruited in the perception of sub- and supra-second intervals. Sub-second timing is subject to local sensory processing, whereas supra-second timing depends on more centralized mechanisms. To clarify the factors that influence time perception, the present study investigated how both sensory modality and timescale affect the central tendency. In Experiment 1, participants were asked to reproduce sub- or supra-second intervals, defined by visual or auditory stimuli. In the sub-second range, the magnitude of the central tendency was significantly larger for visual intervals compared to auditory intervals, while visual and auditory intervals exhibited a correlated and comparable central tendency in the supra-second range. In Experiment 2, the ability to discriminate sub-second intervals in the reproduction task was controlled across modalities by using an interval discrimination task. Even when the ability to discriminate intervals was controlled, visual intervals exhibited a larger central tendency than auditory intervals in the sub-second range. In addition, the magnitude of the central tendency for visual and auditory sub-second intervals was significantly correlated. These results suggest that a common modality-independent mechanism is responsible for the supra-second central tendency, and that both the modality-dependent and modality-independent components of the timing system contribute to the central tendency in the sub-second range.

  1. Timescale- and Sensory Modality-Dependency of the Central Tendency of Time Perception.

    Directory of Open Access Journals (Sweden)

    Yuki Murai

    Full Text Available When individuals are asked to reproduce intervals of stimuli that are intermixedly presented at various times, longer intervals are often underestimated and shorter intervals overestimated. This phenomenon may be attributed to the central tendency of time perception, and suggests that our brain optimally encodes a stimulus interval based on current stimulus input and prior knowledge of the distribution of stimulus intervals. Two distinct systems are thought to be recruited in the perception of sub- and supra-second intervals. Sub-second timing is subject to local sensory processing, whereas supra-second timing depends on more centralized mechanisms. To clarify the factors that influence time perception, the present study investigated how both sensory modality and timescale affect the central tendency. In Experiment 1, participants were asked to reproduce sub- or supra-second intervals, defined by visual or auditory stimuli. In the sub-second range, the magnitude of the central tendency was significantly larger for visual intervals compared to auditory intervals, while visual and auditory intervals exhibited a correlated and comparable central tendency in the supra-second range. In Experiment 2, the ability to discriminate sub-second intervals in the reproduction task was controlled across modalities by using an interval discrimination task. Even when the ability to discriminate intervals was controlled, visual intervals exhibited a larger central tendency than auditory intervals in the sub-second range. In addition, the magnitude of the central tendency for visual and auditory sub-second intervals was significantly correlated. These results suggest that a common modality-independent mechanism is responsible for the supra-second central tendency, and that both the modality-dependent and modality-independent components of the timing system contribute to the central tendency in the sub-second range.

  2. The influence of hallucination proneness and social threat on time perception.

    Science.gov (United States)

    Coy, Abbie L; Hutton, Samuel B

    2013-01-01

    Individuals with schizophrenia frequently report disturbances in time perception, but the precise nature of such deficits and their relation to specific symptoms of the disorder is unclear. We sought to determine the relationship between hallucination proneness and time perception in healthy individuals, and whether this relationship is moderated by hypervigilance to threat-related stimuli. 206 participants completed the Revised Launay-Slade Hallucination Scale (LSHS-R) and a time reproduction task in which, on each trial, participants viewed a face (happy, angry, neutral, or fearful) for between 1 and 5 s and then reproduced the time period with a spacebar press. High LSHS-R scores were associated with longer time estimates, but only during exposure to angry faces. A factor analysis of LSHS-R scores identified a factor comprising items related to reality monitoring, and this factor was most associated with the longer time estimates. During exposure to potential threat in the environment, duration estimates increase with hallucination proneness. The experience of feeling exposed to threat for longer may serve to maintain a state of hypervigilance which has been shown previously to be associated with positive symptoms of schizophrenia.

  3. Functional development of fronto-striato-parietal networks associated with time perception

    Directory of Open Access Journals (Sweden)

    Anna eSmith

    2011-11-01

    Full Text Available Compared to our understanding of the functional maturation of executive functions, little is known about the neurofunctional development of perceptive functions. Time perception develops during late adolescence, underpinning many functions including motor and verbal processing, as well as late maturing higher order cognitive skills such as forward planning and future-related decision-making. Nothing, however, is known about the neurofunctional changes associated with time perception from childhood to adulthood. Using functional magnetic resonance imaging we explored the effects of age on the brain activation and functional connectivity of 32 male participants from 10 to 53 years of age during a time discrimination task that required the discrimination of temporal intervals of seconds differing by several hundred milliseconds. Increasing development was associated with progressive activation increases within left lateralised dorsolateral and inferior fronto-parieto-striato-thalamic brain regions. Furthermore, despite comparable task performance, adults showed increased functional connectivity between inferior/dorsolateral interhemispheric fronto-frontal activation as well as between inferior fronto-parietal regions compared with adolescents. Activation in caudate, specifically, was associated with both increasing age and better temporal discrimination. Progressive decreases in activation with age were observed in ventromedial prefrontal cortex, limbic regions and cerebellum. The findings demonstrate age-dependent developmentally dissociated neural networks for time discrimination. With increasing age there is progressive recruitment of later maturing left hemispheric and lateralised fronto-parieto-striato-thalamic networks, known to mediate time discrimination in adults, while earlier developing brain regions such as ventromedial prefrontal cortex, limbic and paralimbic areas and cerebellum subserve fine-temporal processing functions in children

  4. Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

    Directory of Open Access Journals (Sweden)

    Marjolijn Hoekert

    Full Text Available In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms. Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction, revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become

  5. Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

    Science.gov (United States)

    Hoekert, Marjolijn; Bais, Leonie; Kahn, René S; Aleman, André

    2008-05-21

    In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS) to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms). Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction), revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become more apparent half

  6. Re-designing the everyday; The use and perception of time among cancer patients combining work and treatment

    DEFF Research Database (Denmark)

    Hauge, Bettina

    2016-01-01

    cancer patients performing their jobs while going through demanding treatment programs found time as their main motive for working while being seriously ill. Actions at work point to a time ahead, so by taking part in the time at the workplace they were inscribed in a future presently under pressure...... by their cancer diagnosis. The article describes how cancer struck women and men perceived time in their different life-worlds, at work, at home on temporary sick leave, and at the hospital, and it shows how these perceptions changed during the process of recovery.To these people time appeared in three forms......: A time beyond control, realizing that they had cancer; taking control of time, discovering that they could go to work; the time of the future, which was their new perception of time as cured. This new perception of time reflected the incidental discovery of the cancer, realizing life as coincidental...

  7. The clocks and the perception of time in the 18th century society

    Science.gov (United States)

    Cardinal, Catherine

    The ownership of clocks and watches became widespread in 18th century society, particularly amongst the wealthy classes. They liked the decorative appearance, practical advantages, and social prestige which those objects conferred. The use of 'mechanized' time in the towns supplanted the age old reliance on time as dictated by nature and the Church. New temporal reference points gave the day its rhythm. Data from that era (correspondence, memoirs, newspapers, engravings, and paintings) make it possible to catch a glimpse of the influence of clocks on the perception of time. From the beginning of the 'mechanized time' era, efforts to improve the accuracy and the technical performance of mechanisms were made. The importance of such a precise time measurement in every day life is considered.

  8. Sequential charged particle reaction

    International Nuclear Information System (INIS)

    Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo

    2004-01-01

    The effective cross sections for producing the sequential reaction products in F82H, pure vanadium and LiF with respect to the 14.9-MeV neutron were obtained and compared with the estimation ones. Since the sequential reactions depend on the secondary charged particles behavior, the effective cross sections are corresponding to the target nuclei and the material composition. The effective cross sections were also estimated by using the EAF-libraries and compared with the experimental ones. There were large discrepancies between estimated and experimental values. Additionally, we showed the contribution of the sequential reaction on the induced activity and dose rate in the boundary region with water. From the present study, it has been clarified that the sequential reactions are of great importance to evaluate the dose rates around the surface of cooling pipe and the activated corrosion products. (author)

  9. Face perception is tuned to horizontal orientation in the N170 time window.

    Science.gov (United States)

    Jacques, Corentin; Schiltz, Christine; Goffaux, Valerie

    2014-02-07

    The specificity of face perception is thought to reside both in its dramatic vulnerability to picture-plane inversion and its strong reliance on horizontally oriented image content. Here we asked when in the visual processing stream face-specific perception is tuned to horizontal information. We measured the behavioral performance and scalp event-related potentials (ERP) when participants viewed upright and inverted images of faces and cars (and natural scenes) that were phase-randomized in a narrow orientation band centered either on vertical or horizontal orientation. For faces, the magnitude of the inversion effect (IE) on behavioral discrimination performance was significantly reduced for horizontally randomized compared to vertically or nonrandomized images, confirming the importance of horizontal information for the recruitment of face-specific processing. Inversion affected the processing of nonrandomized and vertically randomized faces early, in the N170 time window. In contrast, the magnitude of the N170 IE was much smaller for horizontally randomized faces. The present research indicates that the early face-specific neural representations are preferentially tuned to horizontal information and offers new perspectives for a description of the visual information feeding face-specific perception.

  10. Perceptions of work-time and leisure-time among managers and field staff in a UK primary health care trust.

    Science.gov (United States)

    Brown, Reva Berman; Adebayo, Shirley A

    2004-09-01

    The aims of the research were to explore the issues around the perception of District Nurses in an inner London Primary Health Care Trust of their use of work-time and leisure-time, and to reveal how the boundaries between these two aspects can become blurred and impinge on each other. Time use is helpful in considerations of wider issues such as satisfaction at work and work-life balance. The data were collected by a questionnaire to seek the views of managers and field staff on issues such as the impact on the quality of patient care of the nurses' perception of work-time and leisure-time. The research identified the different perception of "work-time" that employees have in relation to their place within the hierarchical structure. The findings answered the question of whether time is perceived differently, dependent on one's occupation within the Trust.

  11. Self-Motion Perception: Assessment by Real-Time Computer Generated Animations

    Science.gov (United States)

    Parker, Donald E.

    1999-01-01

    Our overall goal is to develop materials and procedures for assessing vestibular contributions to spatial cognition. The specific objective of the research described in this paper is to evaluate computer-generated animations as potential tools for studying self-orientation and self-motion perception. Specific questions addressed in this study included the following. First, does a non- verbal perceptual reporting procedure using real-time animations improve assessment of spatial orientation? Are reports reliable? Second, do reports confirm expectations based on stimuli to vestibular apparatus? Third, can reliable reports be obtained when self-motion description vocabulary training is omitted?

  12. Tourist Perceptions On Supporting Infrastructure Facilities And Climate-Based Visiting Time Of Ngebel Lake, Ponorogo

    Directory of Open Access Journals (Sweden)

    Ardhila Ayu Prasetyowati

    2014-04-01

    Full Text Available This study aims to analyze the tourists’ perception about the importance and satisfaction on the product of fisheries tourism, and to assess the visiting time of tourist based on climate conditions. The research was conducted in May to June 2013 in Ngebel Lake, Ponorogo. We used descriptive quantitative approach, with 45 respondents. Data collected from interview, questionnaire and observation. Analytical methods were used to determine the perception of tourists on the satisfaction and interest in fisheries tourism products, i.e. Importance Performance Analysis (IPA. We also used Tourism Climate Index (TCI to determine the visiting time of tourist. The results show the value of satisfaction and tourist interest is low, therefore the improvement of several aspects become important. It is encompasses: a the existence of parking area; b the condition of Ngebel Lake; c planning and management system, the condition of the local community; and d activities of fish course restaurant and fish farming system of floating net cages. TCI value indicates ideal conditions for tourists traveled in Ngebel Lake is in November (convenience index value of 106, in December (97 and in April (94. This appropriate time to visit Ngebel Lake is expected to create a good impression for the tourists and enjoy the various fisheries activities in Ngebel Lake. Keywords: Importance Performance Analysis, Ngebel Lake, Tourist Climate Index

  13. Action during body perception: processing time affects self-other correspondences.

    Science.gov (United States)

    Reed, Catherine L; McGoldrick, John E

    2007-01-01

    The accurate perception of other people and their postures is essential for functioning in a social world. Our own bodies organize information from others to help us respond appropriately by creating self-other mappings between bodies. In this study, we investigated mechanisms involved in the processing of self-other correspondences. Reed and Farah (1995) showed that a multimodal, articulated body representation containing the spatial relations among parts of the human body was accessed by both viewing another's body and moving one's own. Use of one part of the body representation facilitated the perception of homologous areas of other people's bodies, suggesting that inputs from both the self and other activated the shared body representation. Here we investigated whether this self-other correspondence produced rapid facilitation or required additional processing time to resolve competing inputs for a shared body representation. Using a modified Reed and Farah dual-task paradigm, we found that processing time influenced body-position memory: an interaction between body-part moved and body-part attended revealed a relative facilitation effect at the 5 s ISI, but interference at the 2 s ISI. Our results suggest that effective visual-motor integration from the self and other requires time to activate shared portions of the spatial body representation.

  14. An Algorithm of Traffic Perception of DDoS Attacks against SOA Based on Time United Conditional Entropy

    Directory of Open Access Journals (Sweden)

    Yuntao Zhao

    2016-01-01

    Full Text Available DDoS attacks can prevent legitimate users from accessing the service by consuming resource of the target nodes, whose availability of network and service is exposed to a significant threat. Therefore, DDoS traffic perception is the premise and foundation of the whole system security. In this paper the method of DDoS traffic perception for SOA network based on time united conditional entropy was proposed. According to many-to-one relationship mapping between the source IP address and destination IP addresses of DDoS attacks, traffic characteristics of services are analyzed based on conditional entropy. The algorithm is provided with perception ability of DDoS attacks on SOA services by introducing time dimension. Simulation results show that the novel method can realize DDoS traffic perception with analyzing abrupt variation of conditional entropy in time dimension.

  15. The color red distorts time perception for men, but not for women.

    Science.gov (United States)

    Shibasaki, Masahiro; Masataka, Nobuo

    2014-07-31

    We investigated the effect of the color red on time perception using a temporal bisection task with human adults. The results showed that the perceived duration of a red screen was longer than was that of a blue screen. However, the results reflected sex differences; men, but not women, overestimated the duration of the red screen. Additionally, the reaction times to a red screen were faster than those to a blue screen, and we found a significant correlation between reaction time and the tendency to overestimate the duration of a red screen. Participants who reacted quickly to a red screen overestimated its duration. These results are discussed within the context of recent studies indicating that the color red exerts certain special psychological effects on human behavior.

  16. Time perception and reproduction in young adults with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Barkley, R A; Murphy, K R; Bush, T

    2001-07-01

    Adults with attention deficit hyperactivity disorder (ADHD; n = 104) were compared with a control group (n = 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than did the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors.

  17. Time, costs and farmers’ perceptions: The case of livestock service delivery in tamilnadu

    Directory of Open Access Journals (Sweden)

    G kathiravan

    2011-10-01

    Full Text Available A study was undertaken in southern peninsular State of India, the Tamil Nadu State, (i to ascertain the time costs of animal health care and bovine breeding services, and (ii to comprehend the perceptions of farmers on the livestock services rendered by different service providers. The districts of the state were categorized as 'Livestock Developed' (LD and 'Livestock Under Developed' (LUD based on initial base line developed. Travel, waiting and service time were among the primary non-price factors that affected service quality. Average travel time was highest for visiting the public veterinary centre in both LUD (23.05 min. and LD (21.32 min. districts. Waiting time with regard to veterinarians providing home services in LUD districts was highest (23.01 min., followed by public veterinary centre services at LUD districts (22.35 min., home services by para-veterinarians (22.01 min. and public veterinary centre services at LD districts (20.10 min.. Both travel and waiting time were much higher in case of breeding services compared to curative services, which could be due to the fact that the farmers preferred Artificial Insemination (AI over its close substitute, the natural service. However, the service time was relatively less in case of insemination services vis-à-vis curative services both in LUD and LD districts. The quality perceptions of farmers on livestock services revealed that the home services rendered by veterinarians as the best one (0.83, followed by private veterinary clinics (0.75, home services by para-veterinarians (0.74, public veterinary centres (0.64 and co-operative veterinary centres (0.48. [Vet. World 2011; 4(5.000: 209-212

  18. General anesthesia alters time perception by phase shifting the circadian clock.

    Science.gov (United States)

    Cheeseman, James F; Winnebeck, Eva C; Millar, Craig D; Kirkland, Lisa S; Sleigh, James; Goodwin, Mark; Pawley, Matt D M; Bloch, Guy; Lehmann, Konstantin; Menzel, Randolf; Warman, Guy R

    2012-05-01

    Following general anesthesia, people are often confused about the time of day and experience sleep disruption and fatigue. It has been hypothesized that these symptoms may be caused by general anesthesia affecting the circadian clock. The circadian clock is fundamental to our well-being because it regulates almost all aspects of our daily biochemistry, physiology, and behavior. Here, we investigated the effects of the most common general anesthetic, isoflurane, on time perception and the circadian clock using the honeybee (Apis mellifera) as a model. A 6-h daytime anesthetic systematically altered the time-compensated sun compass orientation of the bees, with a mean anticlockwise shift in vanishing bearing of 87° in the Southern Hemisphere and a clockwise shift in flight direction of 58° in the Northern Hemisphere. Using the same 6-h anesthetic treatment, time-trained bees showed a delay in the start of foraging of 3.3 h, and whole-hive locomotor-activity rhythms were delayed by an average of 4.3 h. We show that these effects are all attributable to a phase delay in the core molecular clockwork. mRNA oscillations of the central clock genes cryptochrome-m and period were delayed by 4.9 and 4.3 h, respectively. However, this effect is dependent on the time of day of administration, as is common for clock effects, and nighttime anesthesia did not shift the clock. Taken together, our results suggest that general anesthesia during the day causes a persistent and marked shift of the clock effectively inducing "jet lag" and causing impaired time perception. Managing this effect in humans is likely to help expedite postoperative recovery.

  19. Perception of neighborhood safety and screen time in adolescents from Curitiba, Brazil.

    Science.gov (United States)

    Prado, Crisley Vanessa; Rech, Cassiano Ricardo; Hino, Adriano Akira Ferreira; Reis, Rodrigo Siqueira

    2017-01-01

    To analyze the association between perceptions of neighborhood safety (PNS) and screen time among adolescents and to assess the moderating effects of sex, age and socioeconomic status. A cross-sectional study with school survey was conducted in Curitiba, Brazil. First, six schools (three public and three private) were intentionally selected. Next, one class within each educational level (from the sixth year of elementary school to the third year of high school) was randomly selected. PNS was assessed using a NEWS-Y scale, and daily screen time was defined as the time spent watching TV/videos/DVDs, playing video games and using the Internet. Multinomial logistic regression models were used to test the association between PNS and screen time, adjusting for the confounding variables. The sample included 776 adolescents (boys and girls), aged between 11 and 18 years old. Perceived crime was associated with time playing video games among older teenagers (p < 0.05). Pedestrian and traffic safety was inversely associated with time playing video games among adolescents with high socioeconomic status (p < 0.05). The association between PNS and screen time is complex among adolescents and varies according to sociodemographic variables and the screen time outcome (TV/videos/DVDs, video games and the Internet).

  20. A Desire for Growth: Online Full-Time Faculty's Perceptions of Evaluation Processes

    Directory of Open Access Journals (Sweden)

    Meredith DeCosta

    2015-07-01

    Full Text Available Post-secondary educational institutions use various means to evaluate the teaching performance of faculty members. There are benefits to effective faculty evaluation, including advancing the scholarship of teaching and learning, as well as improving the functionality and innovation of courses, curriculum, departments, and ultimately the broader community (Boyer, 1990; Glassick, Huber, & Maeroff, 1997. While there is a body of research related to the evaluation of faculty in traditional settings, there have been fewer studies examining online faculty members’ perceptions of evaluation processes. Further, due to the growth of online education, the existing evaluation scales, including those used in traditional settings, have been questioned (Berk, 2013; Hathorn & Hathorn, 2010; Rothman, Romeo, Brennan, & Mitchell, 2011. This qualitative study examines one university’s online full-time faculty and their perceptions of the tools and processes used to evaluate their teaching. Through a systematic content analysis of survey data, findings indicate that online faculty members have a desire to grow as instructors, infrequently focusing on modality or job expectations as a means for growth. Participants expressed an interest in holistic, descriptive evaluation feedback by a range of stakeholders, particularly those with content knowledge. Study findings have implications for administrators and other stakeholders related to online full-time faculty, including the processes and documents through which they are evaluated.

  1. A Desire for Growth: Online Full-Time Faculty's Perceptions of Evaluation Processes

    Directory of Open Access Journals (Sweden)

    Meredith DeCosta

    2016-07-01

    Full Text Available College and universities evaluate the teaching performance of faculty members in a variety of ways. Benefits to effective faculty evaluation include advancing the scholarship of teaching and learning, as well as improving the functionality and innovation of courses, curriculum, departments, and ultimately the broader community (Boyer, 1990; Glassick, Huber, & Maeroff, 1997. While there is ample research related to the evaluation of faculty in traditional settings, there have been fewer studies examining online faculty members’ perceptions of evaluation processes. Further, due to the growth of online education, the existing evaluation scales, including those used in traditional settings, have been called into question (Berk, 2013; Hathorn & Hathorn, 2010; Rothman, Romeo, Brennan, & Mitchell, 2011. This qualitative study examines one university’s online full-time faculty and their perceptions of the tools and processes used to evaluate their teaching. Through a systematic qualitative content analysis of survey data, findings indicate that online faculty members have a desire to grow as instructors, focusing little on modality or task-oriented expectations as a means for growth. Participants expressed an interest in holistic, descriptive evaluation feedback by a range of stakeholders, particularly those with content knowledge. Study findings have implications for administrators and other stakeholders related to online full-time faculty, including the processes and documents through which they are evaluated.

  2. Just-in-Time Teaching in undergraduate physics courses: Implementation, learning, and perceptions

    Science.gov (United States)

    Dwyer, Jessica Hewitt

    Regardless of discipline, a decades-long battle has ensued within nearly every classroom in higher education: instructors getting students to come to class prepared to learn. In response to this clash between teacher expectations and frequent student neglect, a group of four physics education researchers developed a reformed instructional strategy called Just-in-Time Teaching (JiTT). This dissertation investigates the following three areas: 1) the fidelity with which undergraduate physics instructors implement JiTT, 2) whether student performance predicts student perception of their instructor's fidelity of JiTT implementation, and 3) whether student perception of their instructor's fidelity of JiTT implementation correlates with student views of their physics course. A blend of quantitative data (e.g., students grades, inventory scores, and questionnaire responses) are integrated with qualitative data (e.g., individual faculty interviews, student focus group discussions, and classroom observations). This study revealed no statistically significant relationship between instructors who spent time on a predefined JiTT critical component and their designation as a JiTT user or non-user. While JiTT users implemented the pedagogy in accordance with the creators' intended ideal vision, many also had trouble reconciling personal concerns about their role as a JiTT adopter and the anticipated demand of the innovation. I recommend that this population of faculty members can serve as a JiTT model for other courses, disciplines, and/or institutions. Student performance was not a predictor of student perception instructor fidelity of JiTT implementation. Additionally, the majority of students in this study reported they read their textbook prior to class and that JiTT assignments helped them prepare for in-class learning. I found evidence that exposure to the JiTT strategy may correlate with a more favorable student view of their physics course. Finally, according to students

  3. Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder.

    Science.gov (United States)

    Delphi, Maryam; Lotfi, M-Yones; Moossavi, Abdollah; Bakhshi, Enayatollah; Banimostafa, Maryam

    2017-09-01

    Previous studies have shown that interaural-time-difference (ITD) training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV). We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder. The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months' follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software. Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001). The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months' follow-up (P=0.212). The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

  4. Sequential stochastic optimization

    CERN Document Server

    Cairoli, Renzo

    1996-01-01

    Sequential Stochastic Optimization provides mathematicians and applied researchers with a well-developed framework in which stochastic optimization problems can be formulated and solved. Offering much material that is either new or has never before appeared in book form, it lucidly presents a unified theory of optimal stopping and optimal sequential control of stochastic processes. This book has been carefully organized so that little prior knowledge of the subject is assumed; its only prerequisites are a standard graduate course in probability theory and some familiarity with discrete-paramet

  5. When and How-long: A unified approach for time perception

    Directory of Open Access Journals (Sweden)

    Michail eManiadakis

    2016-03-01

    Full Text Available The representation of the environment assumes the encoding of four basic dimensions in the brain, that is the 3D space and time. The vital role of time for cognition is a topic that recently attracted gradually increasing research interest. Surprisingly, the scientific community investigating mind-time interactions has mainly focused on interval timing, paying less attention on the encoding and processing of distant moments. The present work highlights two basic capacities that are necessary for developing temporal cognition in artificial systems. In particular, the seamless integration of agents in the environment assumes they are able to consider when events have occurred and how long they have lasted. This information, although rather standard in humans, is largely missing from artificial cognitive systems. In the present work we consider how a time perception model that is based on neural networks and the Streatal Beat Frequency (SBF theory is extended in a way that besides the duration of events, facilitates the encoding of the time of occurrence in memory. The extended model is capable to support skills assumed in temporal cognition and answer time-related questions about the unfolded events.

  6. Rapid and acute effects of estrogen on time perception in male and female rats

    Directory of Open Access Journals (Sweden)

    Kristen ePleil

    2011-10-01

    Full Text Available Sex differences in the rapid and acute effects of estrodiol on time perception were investigated in adult male and female Sprague-Dawley rats. Because estrodiol has been shown to increase striatal dopamine release, it may be able to modify time perception and timed performance by increasing the speed of an internal clock in a manner similar to indirect dopamine agonists such as amphetamine and cocaine. Two groups of females (neonatally estradiol-treated/adult ovariectomized and neonatally oil-treated/adult ovariectomized and 2 groups of males (neonatally castrated and adult castrated were trained in a 2 s vs. 8 s duration bisection procedure and tested using intermediate signal durations. After obtaining oil-injected baseline psychometric functions over several days, rats were administered 5μg of estradiol for 4 days and behaviorally evaluated 30 min following each injection. This oil-estradiol administration cycle was subsequently repeated 3 times following the re-establishment of baseline training. Results revealed significant sex differences in the initial baseline functions that were not modifiable by organizational hormones, with males’ duration bisection functions shifted horizontally to the left of females’. Upon the first administration of estradiol, females, but not males, showed a significant, transient leftward shift in their bisection functions, indicative of an increase in clock speed. After extensive retraining in the duration bisection procedure, rats that were exposed to gonadal hormones during the first week of life showed a significant rightward shift in their bisection functions on the fourth day of estradiol administration during each cycle, suggesting a decrease in clock speed. Taken together, our results support the view that there are multiple mechanisms of estrogens’ action in the striatum that modulate dopaminergic activity and are differentially organized by gonadal steroids during early brain development.

  7. Congenital Amusia in linguistic and non-linguistic pitch perception - What behavior and reaction times reveal

    NARCIS (Netherlands)

    Pfeifer, J.; Hamann, S.; Exter, M.; Campbell, N.; Gibbon, D.; Hirst, D.

    2014-01-01

    Congenital Amusia is a developmental disorder that has a negative influence on pitch perception. While it used to be described as a disorder of musical pitch perception, recent studies indicate that congenital amusics also show deficits in linguistic pitch perception. This study investigates the

  8. Computer/Mobile Device Screen Time of Children and Their Eye Care Behavior: The Roles of Risk Perception and Parenting.

    Science.gov (United States)

    Chang, Fong-Ching; Chiu, Chiung-Hui; Chen, Ping-Hung; Miao, Nae-Fang; Chiang, Jeng-Tung; Chuang, Hung-Yi

    2018-03-01

    This study assessed the computer/mobile device screen time and eye care behavior of children and examined the roles of risk perception and parental practices. Data were obtained from a sample of 2,454 child-parent dyads recruited from 30 primary schools in Taipei city and New Taipei city, Taiwan, in 2016. Self-administered questionnaires were collected from students and parents. Fifth-grade students spend more time on new media (computer/smartphone/tablet: 16 hours a week) than on traditional media (television: 10 hours a week). The average daily screen time (3.5 hours) for these children exceeded the American Academy of Pediatrics recommendations (≤2 hours). Multivariate analysis results showed that after controlling for demographic factors, the parents with higher levels of risk perception and parental efficacy were more likely to mediate their child's eye care behavior. Children who reported lower academic performance, who were from non-intact families, reported lower levels of risk perception of mobile device use, had parents who spent more time using computers and mobile devices, and had lower levels of parental mediation were more likely to spend more time using computers and mobile devices; whereas children who reported higher academic performance, higher levels of risk perception, and higher levels of parental mediation were more likely to engage in higher levels of eye care behavior. Risk perception by children and parental practices are associated with the amount of screen time that children regularly engage in and their level of eye care behavior.

  9. Perception of CPR quality: Influence of CPR feedback, Just-in-Time CPR training and provider role.

    Science.gov (United States)

    Cheng, Adam; Overly, Frank; Kessler, David; Nadkarni, Vinay M; Lin, Yiqun; Doan, Quynh; Duff, Jonathan P; Tofil, Nancy M; Bhanji, Farhan; Adler, Mark; Charnovich, Alex; Hunt, Elizabeth A; Brown, Linda L

    2015-02-01

    Many healthcare providers rely on visual perception to guide cardiopulmonary resuscitation (CPR), but little is known about the accuracy of provider perceptions of CPR quality. We aimed to describe the difference between perceived versus measured CPR quality, and to determine the impact of provider role, real-time visual CPR feedback and Just-in-Time (JIT) CPR training on provider perceptions. We conducted secondary analyses of data collected from a prospective, multicenter, randomized trial of 324 healthcare providers who participated in a simulated cardiac arrest scenario between July 2012 and April 2014. Participants were randomized to one of four permutations of: JIT CPR training and real-time visual CPR feedback. We calculated the difference between perceived and measured quality of CPR and reported the proportion of subjects accurately estimating the quality of CPR within each study arm. Participants overestimated achieving adequate chest compression depth (mean difference range: 16.1-60.6%) and rate (range: 0.2-51%), and underestimated chest compression fraction (0.2-2.9%) across all arms. Compared to no intervention, the use of real-time feedback and JIT CPR training (alone or in combination) improved perception of depth (pCPR quality was poor for chest compression depth (0-13%), rate (5-46%) and chest compression fraction (60-63%). Perception of depth is more accurate in CPR providers versus team leaders (27.8% vs. 7.4%; p=0.043) when using real-time feedback. Healthcare providers' visual perception of CPR quality is poor. Perceptions of CPR depth are improved by using real-time visual feedback and with prior JIT CPR training. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Using Zebra-speech to study sequential and simultaneous speech segregation in a cochlear-implant simulation.

    Science.gov (United States)

    Gaudrain, Etienne; Carlyon, Robert P

    2013-01-01

    Previous studies have suggested that cochlear implant users may have particular difficulties exploiting opportunities to glimpse clear segments of a target speech signal in the presence of a fluctuating masker. Although it has been proposed that this difficulty is associated with a deficit in linking the glimpsed segments across time, the details of this mechanism are yet to be explained. The present study introduces a method called Zebra-speech developed to investigate the relative contribution of simultaneous and sequential segregation mechanisms in concurrent speech perception, using a noise-band vocoder to simulate cochlear implants. One experiment showed that the saliency of the difference between the target and the masker is a key factor for Zebra-speech perception, as it is for sequential segregation. Furthermore, forward masking played little or no role, confirming that intelligibility was not limited by energetic masking but by across-time linkage abilities. In another experiment, a binaural cue was used to distinguish the target and the masker. It showed that the relative contribution of simultaneous and sequential segregation depended on the spectral resolution, with listeners relying more on sequential segregation when the spectral resolution was reduced. The potential of Zebra-speech as a segregation enhancement strategy for cochlear implants is discussed.

  11. Sequential memory: Binding dynamics

    Science.gov (United States)

    Afraimovich, Valentin; Gong, Xue; Rabinovich, Mikhail

    2015-10-01

    Temporal order memories are critical for everyday animal and human functioning. Experiments and our own experience show that the binding or association of various features of an event together and the maintaining of multimodality events in sequential order are the key components of any sequential memories—episodic, semantic, working, etc. We study a robustness of binding sequential dynamics based on our previously introduced model in the form of generalized Lotka-Volterra equations. In the phase space of the model, there exists a multi-dimensional binding heteroclinic network consisting of saddle equilibrium points and heteroclinic trajectories joining them. We prove here the robustness of the binding sequential dynamics, i.e., the feasibility phenomenon for coupled heteroclinic networks: for each collection of successive heteroclinic trajectories inside the unified networks, there is an open set of initial points such that the trajectory going through each of them follows the prescribed collection staying in a small neighborhood of it. We show also that the symbolic complexity function of the system restricted to this neighborhood is a polynomial of degree L - 1, where L is the number of modalities.

  12. Mining compressing sequential problems

    NARCIS (Netherlands)

    Hoang, T.L.; Mörchen, F.; Fradkin, D.; Calders, T.G.K.

    2012-01-01

    Compression based pattern mining has been successfully applied to many data mining tasks. We propose an approach based on the minimum description length principle to extract sequential patterns that compress a database of sequences well. We show that mining compressing patterns is NP-Hard and

  13. Art Perception in the Museum: How We Spend Time and Space in Art Exhibitions.

    Science.gov (United States)

    Carbon, Claus-Christian

    2017-01-01

    Aesthetics research aiming at understanding art experience is an emerging field; however, most research is conducted in labs without access to real artworks, without the social context of a museum and without the presence of other persons. The present article replicates and complements key findings of art perception in museum contexts. When observing museum visitors ( N  = 225; 126 female, M (age) = 43.3 years) while perceiving a series of six Gerhard Richter paintings of various sizes (0.26-3.20 sq. m) in a temporary art exhibition in January and February 2015 showing 28 paintings in total, we revealed patterns compatible to previous research. The mean time taken in viewing artworks was much longer than was mostly realized in lab contexts, here 32.9 s ( Mdn  = 25.4 s). We were also able to replicate visitors spending more time on viewing artworks when attending in groups of people. Additionally, we uncovered a close positive relationship ( r 2  = .929) between canvas size and viewing distance, ranging on average between 1.49 and 2.12 m ( M  = 1.72 m). We also found that more than half of the visitors returned to paintings, especially those people who had not previously paid too much attention at the initial viewing. After adding the times of returning viewers, each picture was viewed longer than had been estimated in previous research ( M  = 50.5 s, Mdn  = 43.0 s). Results are discussed in the context of current art perception theories, focusing on the need for the ecologically valid testing of artworks in aesthetics research.

  14. Art Perception in the Museum: How We Spend Time and Space in Art Exhibitions

    Directory of Open Access Journals (Sweden)

    Claus-Christian Carbon

    2017-02-01

    Full Text Available Aesthetics research aiming at understanding art experience is an emerging field; however, most research is conducted in labs without access to real artworks, without the social context of a museum and without the presence of other persons. The present article replicates and complements key findings of art perception in museum contexts. When observing museum visitors (N = 225; 126 female, M(age = 43.3 years while perceiving a series of six Gerhard Richter paintings of various sizes (0.26–3.20 sq. m in a temporary art exhibition in January and February 2015 showing 28 paintings in total, we revealed patterns compatible to previous research. The mean time taken in viewing artworks was much longer than was mostly realized in lab contexts, here 32.9 s (Mdn = 25.4 s. We were also able to replicate visitors spending more time on viewing artworks when attending in groups of people. Additionally, we uncovered a close positive relationship (r2 = .929 between canvas size and viewing distance, ranging on average between 1.49 and 2.12 m (M = 1.72 m. We also found that more than half of the visitors returned to paintings, especially those people who had not previously paid too much attention at the initial viewing. After adding the times of returning viewers, each picture was viewed longer than had been estimated in previous research (M = 50.5 s, Mdn = 43.0 s. Results are discussed in the context of current art perception theories, focusing on the need for the ecologically valid testing of artworks in aesthetics research.

  15. Music, emotion, and time perception: the influence of subjective emotional valence and arousal?

    Science.gov (United States)

    Droit-Volet, Sylvie; Ramos, Danilo; Bueno, José L. O.; Bigand, Emmanuel

    2013-01-01

    The present study used a temporal bisection task with short (2 s) stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow) (Experiment 1) or their instrumentation (orchestral vs. piano pieces). The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant) vs. atonal (unpleasant) versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music. PMID:23882233

  16. Music, Emotion and Time Perception: The influence of subjective emotional valence and arousal?

    Directory of Open Access Journals (Sweden)

    SYLVIE eDROIT-VOLET

    2013-07-01

    Full Text Available The present study used a temporal bisection task with short (< 2 s and long (> 2 s stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow (Experiment 1 or their instrumentation (orchestral vs. piano pieces. The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant versus atonal (unpleasant versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music.

  17. Music, emotion, and time perception: the influence of subjective emotional valence and arousal?

    Science.gov (United States)

    Droit-Volet, Sylvie; Ramos, Danilo; Bueno, José L O; Bigand, Emmanuel

    2013-01-01

    The present study used a temporal bisection task with short (2 s) stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow) (Experiment 1) or their instrumentation (orchestral vs. piano pieces). The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant) vs. atonal (unpleasant) versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music.

  18. Sequential series for nuclear reactions

    International Nuclear Information System (INIS)

    Izumo, Ko

    1975-01-01

    A new time-dependent treatment of nuclear reactions is given, in which the wave function of compound nucleus is expanded by a sequential series of the reaction processes. The wave functions of the sequential series form another complete set of compound nucleus at the limit Δt→0. It is pointed out that the wave function is characterized by the quantities: the number of degrees of freedom of motion n, the period of the motion (Poincare cycle) tsub(n), the delay time t sub(nμ) and the relaxation time tausub(n) to the equilibrium of compound nucleus, instead of the usual quantum number lambda, the energy eigenvalue Esub(lambda) and the total width GAMMAsub(lambda) of resonance levels, respectively. The transition matrix elements and the yields of nuclear reactions also become the functions of time given by the Fourier transform of the usual ones. The Poincare cycles of compound nuclei are compared with the observed correlations among resonance levels, which are about 10 -17 --10 -16 sec for medium and heavy nuclei and about 10 -20 sec for the intermediate resonances. (auth.)

  19. On disturbed time continuity in schizophrenia: an elementary impairment in visual perception?

    Directory of Open Access Journals (Sweden)

    Anne eGiersch

    2013-05-01

    Full Text Available Schizophrenia is associated with a series of visual perception impairments, which might impact on the patients’ every day life and be related to clinical symptoms. However, the heterogeneity of the visual disorders make it a challenge to understand both the mechanisms and the consequences of these impairments, i.e. the way patients experience the outer world. Based on earlier psychiatry literature, we argue that issues regarding time might shed a new light on the disorders observed in patients with schizophrenia. We will briefly review the mechanisms involved in the sense of time continuity and clinical evidence that they are impaired in patients with schizophrenia. We will then summarize a recent experimental approach regarding the coding of time-event structure in time, namely the ability to discriminate between simultaneous and asynchronous events. The use of an original method of analysis allowed us to distinguish between explicit and implicit judgements of synchrony. We showed that for SOAs below 20 ms neither patients nor controls fuse events in time. On the contrary subjects distinguish events at an implicit level even when judging them as synchronous. In addition, the implicit responses of patients and controls differ qualitatively. It is as if controls always put more weight on the last occurred event, whereas patients have a difficulty to follow events in time at an implicit level. In patients, there is a clear dissociation between results at short and large asynchronies, that suggest selective mechanisms for the implicit coding of time-event structure. These results might explain the disruption of the sense of time continuity in patients. We argue that this line of research might also help us to better understand the mechanisms of the visual impairments in patients and how they see their environment.

  20. Environment perception and leisure-time physical activity in Portuguese high school students

    Directory of Open Access Journals (Sweden)

    Rita Pereira

    2018-06-01

    Full Text Available This study aims to analyze the association between perceived environmental factors and leisure-time physical activity (PA among adolescents of both genders. Data were collected in autumn of 2011 from 866 adolescents (412 girls and 454 boys 12- to 18-years-old, from four Portuguese cities. Perception of environmental factors was assessed by Assessing Levels of Physical Activity and Fitness (ALPHA questionnaire (Spittaels et al., 2010, IJBNPA. PA was assessed by a questionnaire that evaluated PA during leisure-time and participants were assigned into the following categories: sedentary; low active; moderate active; and very active. Boys presented higher levels of structured PA, frequency and intensity of PA, and level of sport competition than girls (p<0.001. Distance to local facilities (p=0.001 for girls; p<0.001 for boys and home environment (p=0.004 for girls; p=0.015 for boys were negatively associated with PA. Total, cycling and walking infrastructures (p<0.001, as well as cycling and walking network (p=0.049 and connectivity (p=0.034 showed a positive association with PA in boys. Analysis of variance showed significant differences between girls' PA regarding aesthetics (p=0.013, study environment (p=0.023, home environment (p=0.014 and whether it is pleasant or not (p=0.023. Differences between boys' PA were observed for distance to local facilities (p=0.003, total, cycling and walking infrastructures (p<0.001 and home environment (p=0.002. This study results support that some environmental factors are associated with adolescents' PA levels, with relevant differences between genders. Therefore, these gender differences must be taken into account, in order to increase levels of PA in Portuguese youth, especially in girls. Keywords: Environment perception, Physical activity, Adolescents, ALPHA questionnaire

  1. Perception of Time, Creative Attitudes, and Adoption of Innovations: A Cross-Cultural Study from Chinese and US College Students

    Directory of Open Access Journals (Sweden)

    Seung-Hee Lee

    2016-11-01

    Full Text Available This study explores how earlier (vs. later adopters of innovation differ in time perception and creative attitudes, comparing Chinese and US college students. Research on the perception of time and creative attitudes is useful to understand how sustainability and creative collaboration might work together. Various relationships exist between different levels of innovation adoption groups and creative attitudes or perceptions of time. We found that earlier adopters scored higher on economic time and future time orientation. This may indicate that earlier adopters are sensitive about their planned schedule. Also, earlier adopters with a future time orientation are forward-thinking and anticipate the introduction of new styles, items, or events in the future. We also find that Chinese (vs. US participants scored higher on creative capacity and creative collaboration but did not differ in general creative attitudes or creative risk-taking. For all participants from these two countries, earlier adopters (vs. later scored higher on all aspects of creative attitudes. This study suggests academic and practical implications regarding sustainability issues. From an academic perspective, this study adds a new perspective to the literature about the relationships among time of adoption, time perception, creative attitudes, and cultural values, and is especially useful for how these four variables influence sustainability. From a practitioner perspective, this study provides information of how consumer values and attitudes in a developing economy (China and a developed economy (US might facilitate open innovation and induce sustainability.

  2. Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits.

    Science.gov (United States)

    Righi, Stefania; Galli, Luca; Paganini, Marco; Bertini, Elisabetta; Viggiano, Maria Pia; Piacentini, Silvia

    2016-01-01

    Huntington's disease (HD) primarily affects striatum and prefrontal dopaminergic circuits which are fundamental neural correlates of the timekeeping mechanism. The few studies on HD mainly investigated motor timing performance in second durations. The present work explored time perception in early-to-moderate symptomatic HD patients for seconds and milliseconds with the aim to clarify which component of the scalar expectancy theory (SET) is mainly responsible for HD timing defect. Eleven HD patients were compared to 11 controls employing two separate temporal bisection tasks in second and millisecond ranges. Our results revealed the same time perception deficits for seconds and milliseconds in HD patients. Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits. Furthermore, both the non-systematical defect of temporal sensitivity and the main impairment of timing performance in the extreme value of the psychophysical curves suggested an HD deficit in the memory component of the SET. This result was further confirmed by the significant correlations between time perception performance and long-term memory test scores. Our findings added important preliminary data for both a deeper comprehension of HD time-keeping deficits and possible implications on neuro-rehabilitation practices.

  3. Different Perceptions of Time Passage Among Older People: A Comparative Study in Terms of Age and Gender

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Nazari

    2016-04-01

    Conclusion: Research findings indicate that age affects time perception so that perceived time in the elderly people is shorter than the real physical time. Our findings also showed that if sources pay less attention to the passage of time or the memory capacity declines, the time estimation will be less. Based on cognitive changes in old age, the cognitive abilities of older people were found to decrease with increasing age. As the accurate processing of time intervals relates to memory capacity and attention, the changes in any cognitive process could affect the differences in the perception of time. Probably due to these factors, the reproduction of time in the older people shortens.

  4. Associations of American Indian children's screen-time behavior with parental television behavior, parental perceptions of children's screen time, and media-related resources in the home.

    Science.gov (United States)

    Barr-Anderson, Daheia J; Fulkerson, Jayne A; Smyth, Mary; Himes, John H; Hannan, Peter J; Holy Rock, Bonnie; Story, Mary

    2011-09-01

    American Indian children have high rates of overweight and obesity, which may be partially attributable to screen-time behavior. Young children's screen-time behavior is strongly influenced by their environment and their parents' behavior. We explored whether parental television watching time, parental perceptions of children's screen time, and media-related resources in the home are related to screen time (ie, television, DVD/video, video game, and computer use) among Oglala Lakota youth residing on or near the Pine Ridge Reservation in South Dakota. We collected baseline data from 431 child and parent/caregiver pairs who participated in Bright Start, a group-randomized, controlled, school-based obesity prevention trial to reduce excess weight gain. Controlling for demographic characteristics, we used linear regression analysis to assess associations between children's screen time and parental television watching time, parental perceptions of children's screen time, and availability of media-related household resources. The most parsimonious model for explaining child screen time included the children's sex, parental body mass index, parental television watching time, how often the child watched television after school or in the evening, parental perception that the child spent too much time playing video games, how often the parent limited the child's television time, and the presence of a VCR/DVD player or video game player in the home (F(7,367) = 14.67; P strategy for reducing overweight and obesity in American Indian children.

  5. Real-time multiple human perception with color-depth cameras on a mobile robot.

    Science.gov (United States)

    Zhang, Hao; Reardon, Christopher; Parker, Lynne E

    2013-10-01

    The ability to perceive humans is an essential requirement for safe and efficient human-robot interaction. In real-world applications, the need for a robot to interact in real time with multiple humans in a dynamic, 3-D environment presents a significant challenge. The recent availability of commercial color-depth cameras allow for the creation of a system that makes use of the depth dimension, thus enabling a robot to observe its environment and perceive in the 3-D space. Here we present a system for 3-D multiple human perception in real time from a moving robot equipped with a color-depth camera and a consumer-grade computer. Our approach reduces computation time to achieve real-time performance through a unique combination of new ideas and established techniques. We remove the ground and ceiling planes from the 3-D point cloud input to separate candidate point clusters. We introduce the novel information concept, depth of interest, which we use to identify candidates for detection, and that avoids the computationally expensive scanning-window methods of other approaches. We utilize a cascade of detectors to distinguish humans from objects, in which we make intelligent reuse of intermediary features in successive detectors to improve computation. Because of the high computational cost of some methods, we represent our candidate tracking algorithm with a decision directed acyclic graph, which allows us to use the most computationally intense techniques only where necessary. We detail the successful implementation of our novel approach on a mobile robot and examine its performance in scenarios with real-world challenges, including occlusion, robot motion, nonupright humans, humans leaving and reentering the field of view (i.e., the reidentification challenge), human-object and human-human interaction. We conclude with the observation that the incorporation of the depth information, together with the use of modern techniques in new ways, we are able to create an

  6. Successful Combination of Sequential Gene Therapy and Rescue Allo-HSCT in Two Children with X-CGD - Importance of Timing.

    Science.gov (United States)

    Siler, Ulrich; Paruzynski, Anna; Holtgreve-Grez, Heidi; Kuzmenko, Elena; Koehl, Ulrike; Renner, Eleonore D; Alhan, Canan; de Loosdrecht, Arjan A van; Schwäble, Joachim; Pfluger, Thomas; Tchinda, Joelle; Schmugge, Markus; Jauch, Anna; Naundorf, Sonja; Kühlcke, Klaus; Notheis, Gundula; Güngor, Tayfun; Kalle, Christof V; Schmidt, Manfred; Grez, Manuel; Seger, Reinhard; Reichenbach, Janine

    2015-01-01

    We report on a series of sequential events leading to long-term survival and cure of pediatric X-linked chronic granulomatous disease (X-CGD) patients after gamma-retroviral gene therapy (GT) and rescue HSCT. Due to therapyrefractory life-threatening infections requiring hematopoietic stem cell transplantation (HSCT) but absence of HLAidentical donors, we treated 2 boys with X-CGD by GT. Following GT both children completely resolved invasive Aspergillus nidulans infections. However, one child developed dual insertional activation of ecotropic viral integration site 1 (EVI1) and signal transducer and activator of transcription 3 (STAT3) genes, leading to myelodysplastic syndrome (MDS) with monosomy 7. Despite resistance to mismatched allo-HSCT with standard myeloablative conditioning, secondary intensified rescue allo-HSCT resulted in 100 % donor chimerism and disappearance of MDS. The other child did not develop MDS despite expansion of a clone with a single insertion in the myelodysplasia syndrome 1 (MDS1) gene and was cured by early standard allo-HSCT. The slowly developing dominance of clones harboring integrations in MDS1-EVI1 may guide clinical intervention strategies, i.e. early rescue allo-HSCT, prior to malignant transformation. GT was essential for both children to survive and to clear therapy-refractory infections, and future GT with safer lentiviral self-inactivated (SIN) vectors may offer a therapeutic alternative for X-CGD patients suffering from life-threatening infections and lacking HLA-identical HSC donors.

  7. Forced Sequence Sequential Decoding

    DEFF Research Database (Denmark)

    Jensen, Ole Riis

    In this thesis we describe a new concatenated decoding scheme based on iterations between an inner sequentially decoded convolutional code of rate R=1/4 and memory M=23, and block interleaved outer Reed-Solomon codes with non-uniform profile. With this scheme decoding with good performance...... is possible as low as Eb/No=0.6 dB, which is about 1.7 dB below the signal-to-noise ratio that marks the cut-off rate for the convolutional code. This is possible since the iteration process provides the sequential decoders with side information that allows a smaller average load and minimizes the probability...... of computational overflow. Analytical results for the probability that the first Reed-Solomon word is decoded after C computations are presented. This is supported by simulation results that are also extended to other parameters....

  8. Sequential Power-Dependence Theory

    NARCIS (Netherlands)

    Buskens, Vincent; Rijt, Arnout van de

    2008-01-01

    Existing methods for predicting resource divisions in laboratory exchange networks do not take into account the sequential nature of the experimental setting. We extend network exchange theory by considering sequential exchange. We prove that Sequential Power-Dependence Theory—unlike

  9. Modelling sequentially scored item responses

    NARCIS (Netherlands)

    Akkermans, W.

    2000-01-01

    The sequential model can be used to describe the variable resulting from a sequential scoring process. In this paper two more item response models are investigated with respect to their suitability for sequential scoring: the partial credit model and the graded response model. The investigation is

  10. Physical activity and sedentary time: male perceptions in a university work environment.

    Science.gov (United States)

    George, Emma S; Kolt, Gregory S; Rosenkranz, Richard R; Guagliano, Justin M

    2014-03-01

    Promoting physical activity and reducing sedentary time in males can be challenging, and interventions tailored specifically for males are limited. Understanding male perceptions of physical activity and sedentary behavior is important to inform development of relevant interventions, especially for males working in an office setting. As part of a larger intervention study to increase physical activity and reduce sedentary time, male university employees aged 35 to 64 years were invited to partake in focus groups to discuss benefits, motivators, and barriers related to physical activity and sedentary time. Five semistructured focus group sessions, ranging from 50 to 70 minutes in duration, were conducted on two campuses at an Australian university. A total of 15 participants (9 academic/faculty staff and 6 professional staff), with a mean (± SD) age of 46.1 (±8.0) years took part in the study. Health and family were commonly discussed motivators for physical activity, whereas time constraints and work commitments were major barriers to physical activity participation. Sedentary time was a perceived "by-product" of participants' university employment, as a substantial proportion of their days were spent sitting, primarily at a computer. Participants believed that physical activity should be recognized as a legitimate activity at work, embedded within the university culture and endorsed using a top-down approach. It is important to encourage breaks in sedentary time and recognize physical activity as a legitimate health-promoting activity that is supported and encouraged during working hours. These findings can be used as a platform from which to develop targeted strategies to promote physical activity in male university employees.

  11. Forced Sequence Sequential Decoding

    DEFF Research Database (Denmark)

    Jensen, Ole Riis; Paaske, Erik

    1998-01-01

    We describe a new concatenated decoding scheme based on iterations between an inner sequentially decoded convolutional code of rate R=1/4 and memory M=23, and block interleaved outer Reed-Solomon (RS) codes with nonuniform profile. With this scheme decoding with good performance is possible as low...... as Eb/N0=0.6 dB, which is about 1.25 dB below the signal-to-noise ratio (SNR) that marks the cutoff rate for the full system. Accounting for about 0.45 dB due to the outer codes, sequential decoding takes place at about 1.7 dB below the SNR cutoff rate for the convolutional code. This is possible since...... the iteration process provides the sequential decoders with side information that allows a smaller average load and minimizes the probability of computational overflow. Analytical results for the probability that the first RS word is decoded after C computations are presented. These results are supported...

  12. Involving young people in decision making about sequential cochlear implantation.

    Science.gov (United States)

    Ion, Rebecca; Cropper, Jenny; Walters, Hazel

    2013-11-01

    The National Institute for Health and Clinical Excellence guidelines recommended young people who currently have one cochlear implant be offered assessment for a second, sequential implant, due to the reported improvements in sound localization and speech perception in noise. The possibility and benefits of group information and counselling assessments were considered. Previous research has shown advantages of group sessions involving young people and their families and such groups which also allow young people opportunity to discuss their concerns separately to their parents/guardians are found to be 'hugely important'. Such research highlights the importance of involving children in decision-making processes. Families considering a sequential cochlear implant were invited to a group information/counselling session, which included time for parents and children to meet separately. Fourteen groups were held with approximately four to five families in each session, totalling 62 patients. The sessions were facilitated by the multi-disciplinary team, with a particular psychological focus in the young people's session. Feedback from families has demonstrated positive support for this format. Questionnaire feedback, to which nine families responded, indicated that seven preferred the group session to an individual session and all approved of separate groups for the child and parents/guardians. Overall the group format and psychological focus were well received in this typically surgical setting and emphasized the importance of involving the young person in the decision-making process. This positive feedback also opens up the opportunity to use a group format in other assessment processes.

  13. Group-sequential analysis may allow for early trial termination

    DEFF Research Database (Denmark)

    Gerke, Oke; Vilstrup, Mie H; Halekoh, Ulrich

    2017-01-01

    BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG-PET/CT mea......BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG...

  14. Effects of psilocybin on time perception and temporal control of behaviour in humans.

    Science.gov (United States)

    Wittmann, Marc; Carter, Olivia; Hasler, Felix; Cahn, B Rael; Grimberg, Ulrike; Spring, Philipp; Hell, Daniel; Flohr, Hans; Vollenweider, Franz X

    2007-01-01

    Hallucinogenic psilocybin is known to alter the subjective experience of time. However, there is no study that systematically investigated objective measures of time perception under psilocybin. Therefore, we studied dose-dependent effects of the serotonin (5-HT)2A/1A receptor agonist psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine) on temporal processing, employing tasks of temporal reproduction, sensorimotor synchronization and tapping tempo. To control for cognitive and subjective changes, we assessed spatial working memory and conscious experience. Twelve healthy human volunteers were tested under placebo, medium (115 microg/kg), and high (250 microg/kg) dose conditions, in a double-blind experimental design. Psilocybin was found to significantly impair subjects' ability to (1) reproduce interval durations longer than 2.5 sec, (2) to synchronize to inter-beat intervals longer than 2 sec and (3) caused subjects to be slower in their preferred tapping rate. These objective effects on timing performance were accompanied by working-memory deficits and subjective changes in conscious state, namely increased reports of 'depersonalization' and 'derealization' phenomena including disturbances in subjective 'time sense.' Our study is the first to systematically assess the impact of psilocybin on timing performance on standardized measures of temporal processing. Results indicate that the serotonin system is selectively involved in duration processing of intervals longer than 2 to 3 seconds and in the voluntary control of the speed of movement. We speculate that psilocybin's selective disruption of longer intervals is likely to be a product of interactions with cognitive dimensions of temporal processing -presumably via 5-HT2A receptor stimulation.

  15. Perceptions of Pediatric Nephrologists regarding Timing of Dialysis Initiation in Children in Canada

    Directory of Open Access Journals (Sweden)

    Jeremy A. Saban

    2016-07-01

    Full Text Available Background: Significant practice variation exists in Canada with respect to timing of dialysis initiation in children. In the absence of evidence to guide practice, physicians' perceptions may significantly influence decision-making. Objective: The objectives of this study are to (1 evaluate Canadian pediatric nephrologists' perceptions regarding dialysis initiation in children with chronic kidney disease (CKD and (2 determine the factors guiding practice that may contribute to practice variation across Canada. Design: This study was a cross-sectional online survey. Setting: This study was done in academic pediatric nephrology centers in Canada. Participants: The participants of this study are pediatric nephrologists. Measurements and methods: An anonymous web-based survey was administered to pediatric nephrologists in Canada to evaluate perspectives and practice patterns regarding timing of dialysis initiation. We also explored the importance of estimated glomerular filtration rate (eGFR vs. symptoms and the role of patient and provider factors influencing decisions. Results: Thirty-five nephrologists (59 % completed the survey. Most respondents care for advanced CKD patients in a multidisciplinary clinic (86 % and no centers have a formal policy on timing of dialysis initiation. Seventy-five percent of centers follow 30 patients. Discussions about dialysis initiation are generally informal (75 % and the decision to start is made by the nephrologist (37 % or a team (57 %. Fifty percent agreed GFR was important when deciding when to initiate dialysis, 41 % were neutral, and 9 % disagreed. Variability exists in the threshold that nephrologists considered early (vs. late dialysis initiation: >20 (21 %, >15 (38 %, >12 (26 %, and >10 ml/min/1.73 m 2 (12 %. Practitioners however typically start dialysis in asymptomatic patients at eGFRs of 7–9 (9 %, 10–11 (41 %, 12–14 (38 %, and 15–19 (6 % ml/min/1.73 m 2 . Patient factors important in the

  16. Attention switching during scene perception: how goals influence the time course of eye movements across advertisements.

    Science.gov (United States)

    Wedel, Michel; Pieters, Rik; Liechty, John

    2008-06-01

    Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a free-viewing condition, and a scene-learning goal (ad memorization), a scene-evaluation goal (ad appreciation), a target-learning goal (product learning), or a target-evaluation goal (product evaluation). The model reflects how attention switches between two states--local and global--expressed in saccades of shorter and longer amplitude on a spatial grid with 48 cells overlaid on the ads. During the 5- to 6-s duration of self-controlled exposure to ads in the magazine context, attention predominantly started in the local state and ended in the global state, and rapidly switched about 5 times between states. The duration of the local attention state was much longer than the duration of the global state. Goals affected the frequency of switching between attention states and the duration of the local, but not of the global, state. (c) 2008 APA, all rights reserved

  17. Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder

    Directory of Open Access Journals (Sweden)

    Maryam Delphi

    2017-09-01

    Full Text Available Background: Previous studies have shown that interaural-time-difference (ITD training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV. We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder. Methods: The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months’ follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software. Results: Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001. The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months’ follow-up (P=0.212. Conclusion: The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

  18. “Patient-Time,” “Doctor-Time,” and “Institution-Time”: Perceptions and Definitions of Time Among Doctors Who Become Patients

    Science.gov (United States)

    Klitzman, Robert

    2010-01-01

    Objective To examine views and experiences of conflicts concerning time in healthcare, from the perspective of physicians who have become patients. Methods We conducted two in-depth semi-structured two-hour interviews concerning experiences of being health care workers, and becoming a patient, with each of 50 doctors who had serious illnesses. Results These doctor-patients often came to realize as they had not before how patients experience time differently, and how “patient-time,” “doctor-time,” and “institution-time” exist and can conflict. Differences arose in both long and short term, regarding historical time (prior eras/decades in medicine), prognosis (months/years), scheduling delays (days/weeks), daily medical events and tasks (hours), and periods in waiting rooms (minutes/hours). Definitions of periods of time (e.g., “fast,” “slow,” “plenty,” and “soon”) also varied widely, and could clash. Professional socialization had heretofore impeded awareness of these differences. Physicians tried to address these conflicts in several ways (e.g., trying to provide test results promptly), though full resolution remained difficult. Conclusions Doctors who became patients often now realized how physicians and patients differ in subjective experiences of time. Medical education and research have not adequately considered these issues, which can affect patient satisfaction, doctor-patient relationships and communication, and care. Practice Implications Physicians need to be more sensitive to how their definitions, perceptions, and experiences concerning time can differ from those of patients. PMID:17125956

  19. Effect of drivers' age and push button locations on visual time off road, steering wheel deviation and safety perception.

    Science.gov (United States)

    Dukic, T; Hanson, L; Falkmer, T

    2006-01-15

    The study examined the effects of manual control locations on two groups of randomly selected young and old drivers in relation to visual time off road, steering wheel deviation and safety perception. Measures of visual time off road, steering wheel deviations and safety perception were performed with young and old drivers during real traffic. The results showed an effect of both driver's age and button location on the dependent variables. Older drivers spent longer visual time off road when pushing the buttons and had larger steering wheel deviations. Moreover, the greater the eccentricity between the normal line of sight and the button locations, the longer the visual time off road and the larger the steering wheel deviations. No interaction effect between button location and age was found with regard to visual time off road. Button location had an effect on perceived safety: the further away from the normal line of sight the lower the rating.

  20. The Effects of Textisms on Learning, Study Time, and Instructional Perceptions in an Online Artificial Intelligence Instructional Module

    Science.gov (United States)

    Beasley, Robert; Bryant, Nathan L.; Dodson, Phillip T.; Entwistle, Kevin C.

    2013-01-01

    The purpose of this study was to investigate the effects of textisms (i.e., abbreviated spellings, acronyms, and other shorthand notations) on learning, study time, and instructional perceptions in an online artificial intelligence instructional module. The independent variable in this investigation was experimental condition. For the control…

  1. The effects of music on time perception and performance of a driving game.

    Science.gov (United States)

    Cassidy, G G; Macdonald, R A R

    2010-12-01

    There is an established and growing body of evidence highlighting that music can influence behavior across a range of diverse domains (Miell, MacDonald, & Hargreaves 2005). One area of interest is the monitoring of "internal timing mechanisms", with features such as tempo, liking, perceived affective nature and everyday listening contexts implicated as important (North & Hargreaves, 2008). The current study addresses these issues by comparing the effects of self-selected and experimenter-selected music (fast and slow) on actual and perceived performance of a driving game activity. Seventy participants completed three laps of a driving game in seven sound conditions: (1) silence; (2) car sounds; (3) car sounds with self-selected music, and car sounds with experimenter-selected music; (4) high-arousal (70 bpm); (5) high-arousal (130 bpm); (6) low-arousal (70 bpm); and (7) low-arousal (130 bpm) music. Six performance measures (time, accuracy, speed, and retrospective perception of these), and four experience measures (perceived distraction, liking, appropriateness and enjoyment) were taken. Exposure to self-selected music resulted in overestimation of elapsed time and inaccuracy, while benefiting accuracy and experience. In contrast, exposure to experimenter-selected music resulted in poorest performance and experience. Increasing the tempo of experimenter-selected music resulted in faster performance and increased inaccuracy for high-arousal music, but did not impact experience. It is suggested that personal meaning and subjective associations connected to self-selected music promoted increased engagement with the activity, overriding detrimental effects attributed to unfamiliar, less liked and less appropriate experimenter-selected music. © 2010 The Authors. Scandinavian Journal of Psychology © 2010 The Scandinavian Psychological Associations.

  2. How is time perspective related to perceptions of self and of interpersonal relationships?

    Science.gov (United States)

    Akirmak, Umit

    2014-12-17

    Previous research has revealed a positive association between balanced time perspective (BTP) and subjective well-being (Boniwell & Zimbardo, 2004), however mechanisms underlying BTP are yet to be determined. The goal of the present study was to examine the contributions of personality and quality of interpersonal relationships in the development of BTP. Additionally, the correlations between these measures and time perspective dimensions were evaluated as an attempt to provide further psychometric properties of the Zimbardo Time Perspective Inventory (ZTPI) in a Turkish sample. 178 undergraduates filled out a survey that included the ZTPI and measures that assessed personality characteristics, and quality of parent, peer, and adult relationships. Results showed that deviation from BTP was positively associated with romantic anxiety (r = .41, p < .001), romantic avoidance (r = .33, p < .001), and neuroticism (r = .49, p < .001) but negatively associated with self-esteem (r = -.50, p < .001) and security of the mother (r = -.38, p < .001), father (r = -.37, p < .001) and peer (r = -.27, p < .001) attachment. When personality and attachment measures were employed in a regression analysis, father attachment, romantic anxiety, self-esteem, and neuroticism were found to be significant predictors of the deviation from BTP scores (adjusted R 2 = .39, f 2 = .75). Finally, the inter-correlations of the ZTPI dimensions and their correlations with the personality and attachment measures provided additional support for the validity and reliability of the Turkish version of the ZTPI. These findings imply that positive perceptions of self and of interpersonal relationships are crucial in the development of BTP.

  3. Sequential decay of Reggeons

    International Nuclear Information System (INIS)

    Yoshida, Toshihiro

    1981-01-01

    Probabilities of meson production in the sequential decay of Reggeons, which are formed from the projectile and the target in the hadron-hadron to Reggeon-Reggeon processes, are investigated. It is assumed that pair creation of heavy quarks and simultaneous creation of two antiquark-quark pairs are negligible. The leading-order terms with respect to ratio of creation probabilities of anti s s to anti u u (anti d d) are calculated. The production cross sections in the target fragmentation region are given in terms of probabilities in the initial decay of the Reggeons and an effect of manyparticle production. (author)

  4. Sequential probability ratio controllers for safeguards radiation monitors

    International Nuclear Information System (INIS)

    Fehlau, P.E.; Coop, K.L.; Nixon, K.V.

    1984-01-01

    Sequential hypothesis tests applied to nuclear safeguards accounting methods make the methods more sensitive to detecting diversion. The sequential tests also improve transient signal detection in safeguards radiation monitors. This paper describes three microprocessor control units with sequential probability-ratio tests for detecting transient increases in radiation intensity. The control units are designed for three specific applications: low-intensity monitoring with Poisson probability ratios, higher intensity gamma-ray monitoring where fixed counting intervals are shortened by sequential testing, and monitoring moving traffic where the sequential technique responds to variable-duration signals. The fixed-interval controller shortens a customary 50-s monitoring time to an average of 18 s, making the monitoring delay less bothersome. The controller for monitoring moving vehicles benefits from the sequential technique by maintaining more than half its sensitivity when the normal passage speed doubles

  5. HIV-Positive Patients' Perceptions of Antiretroviral Therapy Adherence in Relation to Subjective Time: Imprinting, Domino Effects, and Future Shadowing.

    Science.gov (United States)

    Lessard, David; Toupin, Isabelle; Engler, Kim; Lènàrt, Andràs; Lebouché, Bertrand

    2018-01-01

    Antiretroviral treatment adherence barriers are major concerns in HIV care. They are multiple and change over time. Considering temporality in patients' perceptions of adherence barriers could improve adherence management. We explored how temporality manifests itself in patients' perceptions of adherence barriers. We conducted 2 semi-structured focus groups on adherence barriers with 12 adults with HIV which were analyzed with grounded theory. A third focus group served to validate the results obtained. Three temporal categories were manifest in HIV-positive patients' perceptions of barriers: (1) imprinting (events with lasting impacts on patients), (2) domino effects (chain of life events), and (3) future shadowing (apprehension about long-term adherence). An overarching theme, weathering (gradual erosion of abilities to adhere), traversed these categories. These temporalities explain how similar barriers may be perceived differently by patients. They could be useful to providers for adapting their interventions and improving understanding of patients' subjective experience of adherence.

  6. Synthetic Aperture Sequential Beamforming

    DEFF Research Database (Denmark)

    Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

    2008-01-01

    A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective is to im......A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective...... is to improve and obtain a more range independent lateral resolution compared to conventional dynamic receive focusing (DRF) without compromising frame rate. SASB is a two-stage procedure using two separate beamformers. First a set of Bmode image lines using a single focal point in both transmit and receive...... is stored. The second stage applies the focused image lines from the first stage as input data. The SASB method has been investigated using simulations in Field II and by off-line processing of data acquired with a commercial scanner. The performance of SASB with a static image object is compared with DRF...

  7. Sequential dependencies in magnitude scaling of loudness

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Jesteadt, Walt

    2013-01-01

    Ten normally hearing listeners used a programmable sone-potentiometer knob to adjust the level of a 1000-Hz sinusoid to match the loudness of numbers presented to them in a magnitude production task. Three different power-law exponents (0.15, 0.30, and 0.60) and a log-law with equal steps in d......B were used to program the sone-potentiometer. The knob settings systematically influenced the form of the loudness function. Time series analysis was used to assess the sequential dependencies in the data, which increased with increasing exponent and were greatest for the log-law. It would be possible......, therefore, to choose knob properties that minimized these dependencies. When the sequential dependencies were removed from the data, the slope of the loudness functions did not change, but the variability decreased. Sequential dependencies were only present when the level of the tone on the previous trial...

  8. Hospital employees' perceptions of fairness and job satisfaction at a time of transformational change.

    Science.gov (United States)

    Brandis, Susan; Fisher, Ron; McPhail, Ruth; Rice, John; Eljiz, Kathy; Fitzgerald, Anneke; Gapp, Rod; Marshall, Andrea

    2016-06-01

    Objective This study examines the relationships between job satisfaction and organisational justice during a time of transformational change. Methods Data collection occurred immediately before a major regional hospital's move to a greenfield site. Existing measures of job satisfaction and organisational justice were used. Data were analysed (n=316) using descriptive, correlation and regression methods together with interactions between predictor variables. Results Correlation coefficients for satisfaction and organisational justice variables were high and significant at the Pemployee job satisfaction. Interactions between the predictor variables showed that job satisfaction increased as the interactions between the predictor variables increased. Conclusions The finding that even at a time of transformational change staff perceptions of fair treatment will in the main result in high job satisfaction extends the literature in this area. In addition, it was found that increasing rewards for staff who perceive low levels of organisational justice does not increase satisfaction as much as for staff who perceive high levels of fairness. If people feel negative about their role, but feel they are well paid, they probably still have negative feelings overall. What is known about the topic? Despite much research highlighting the importance of job satisfaction and organisational justice in healthcare, no research has examined the influence of transformational change, such as a healthcare organisational relocation, on these factors. What does this paper add? The research adds to academic literature relating to job satisfaction and organisational justice. It highlights the importance of organisational justice in influencing the job satisfaction of staff. What are the implications for practitioners? Financial rewards do not necessarily motivate staff but low rewards do demotivate. Shortages of health professionals are often linked to a lack of job satisfaction, and recruitment

  9. Consumer Food Safety Risk Attitudes and Perceptions Over Time: The Case of BSE Crisis

    OpenAIRE

    Kalogeras, Nikos; Pennings, Joost M.E.; van Ittersum, Koert

    2008-01-01

    Recent research has shown that by decoupling the risk response behaviour of consumers into the separate components of risk perception and risk attitude, a more robust conceptualization and prediction of consumers’ reactions to food safety issues is possible. Furthermore, it has been argued that the influence of risk attitudes and risk perceptions on consumer risk behaviour for contaminated food products can be used to formulate effective agricultural policies and strategies in case of a food ...

  10. Spike Timing Matters in Novel Neuronal Code Involved in Vibrotactile Frequency Perception.

    Science.gov (United States)

    Birznieks, Ingvars; Vickery, Richard M

    2017-05-22

    Skin vibrations sensed by tactile receptors contribute significantly to the perception of object properties during tactile exploration [1-4] and to sensorimotor control during object manipulation [5]. Sustained low-frequency skin vibration (perception of frequency is still unknown. Measures based on mean spike rates of neurons in the primary somatosensory cortex are sufficient to explain performance in some frequency discrimination tasks [7-11]; however, there is emerging evidence that stimuli can be distinguished based also on temporal features of neural activity [12, 13]. Our study's advance is to demonstrate that temporal features are fundamental for vibrotactile frequency perception. Pulsatile mechanical stimuli were used to elicit specified temporal spike train patterns in tactile afferents, and subsequently psychophysical methods were employed to characterize human frequency perception. Remarkably, the most salient temporal feature determining vibrotactile frequency was not the underlying periodicity but, rather, the duration of the silent gap between successive bursts of neural activity. This burst gap code for frequency represents a previously unknown form of neural coding in the tactile sensory system, which parallels auditory pitch perception mechanisms based on purely temporal information where longer inter-pulse intervals receive higher perceptual weights than short intervals [14]. Our study also demonstrates that human perception of stimuli can be determined exclusively by temporal features of spike trains independent of the mean spike rate and without contribution from population response factors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. A framework for sequential multiblock component methods

    NARCIS (Netherlands)

    Smilde, A.K.; Westerhuis, J.A.; Jong, S.de

    2003-01-01

    Multiblock or multiset methods are starting to be used in chemistry and biology to study complex data sets. In chemometrics, sequential multiblock methods are popular; that is, methods that calculate one component at a time and use deflation for finding the next component. In this paper a framework

  12. Sequential Analysis: Hypothesis Testing and Changepoint Detection

    Science.gov (United States)

    2014-07-11

    maintains the flexibility of deciding sooner than the fixed sample size procedure at the price of some lower power [13, 514]. The sequential probability... markets , detection of signals with unknown arrival time in seismology, navigation, radar and sonar signal processing, speech segmentation, and the... skimming cruise missile can yield a significant increase in the probability of raid annihilation. Furthermore, usually detection systems are

  13. Retrieval of sea surface velocities using sequential Ocean Colour ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    pended sediment dispersion patterns, in sequential two time lapsed images. .... face advective velocities consists essentially of iden- tifying the ... matrix is time consuming, a significant reduction .... Chauhan, P. 2002 Personal Communication.

  14. Retrieval of sea surface velocities using sequential ocean colour monitor (OCM) data

    Digital Repository Service at National Institute of Oceanography (India)

    Prasad, J.S.; Rajawat, A.S.; Pradhan, Y.; Chauhan, O.S.; Nayak, S.R.

    velocities has been developed. The method is based on matching suspended sediment dispersion patterns, in sequential two time lapsed images. The pattern matching is performed on atmospherically corrected and geo-referenced sequential pair of images by Maximum...

  15. Changes in Student Perceptions and Study Strategies Over Time in a Veterinary Clinical Pathology Course Using Case-Based Instruction.

    Science.gov (United States)

    Fernandez, Nicole J; Wagg, Catherine R; Warren, Amy L

    2018-06-13

    Veterinary students are challenged to develop new, nonlinear ways of thinking as they learn diagnostic reasoning skills. To support this process, we use real-life cases in our clinical pathology course. Changes in student perceptions regarding the use of cases and changes in study strategies over time have not been previously investigated or compared to student grades. Students participated in three voluntary online surveys that included 4-point Likert scale questions and open-ended questions on the helpfulness of cases for learning and study strategies used during the course. We used Friedman tests to detect any differences in perceptions over time; McNemar's test and "Wilcoxon signed-rank tests were used to detect any differences in study strategies over time. Fisher's exact tests'were used to examine the association between the Likert scale responses and grades in quartiles. Before beginning the course, 29% of students responded that cases were very helpful to their learning, with similar "responses for helpfulness in applying course material and grasping important concepts. There was a significant trend of increasing positivity over the duration of the course, with 74% responding that cases were very helpful at the end of the course. The most-reported study strategy was working individually on cases before the midterm (74% of students), and the most helpful study strategy was attending class regularly (88% reported it as very "helpful). Study strategies did not change significantly over time. Overall, perceptions and study strategies did not vary significantly with grades.

  16. Work–Family Conflict and Mental Health Among Female Employees: A Sequential Mediation Model via Negative Affect and Perceived Stress

    Science.gov (United States)

    Zhou, Shiyi; Da, Shu; Guo, Heng; Zhang, Xichao

    2018-01-01

    After the implementation of the universal two-child policy in 2016, more and more working women have found themselves caught in the dilemma of whether to raise a baby or be promoted, which exacerbates work–family conflicts among Chinese women. Few studies have examined the mediating effect of negative affect. The present study combined the conservation of resources model and affective events theory to examine the sequential mediating effect of negative affect and perceived stress in the relationship between work–family conflict and mental health. A valid sample of 351 full-time Chinese female employees was recruited in this study, and participants voluntarily answered online questionnaires. Pearson correlation analysis, structural equation modeling, and multiple mediation analysis were used to examine the relationships between work–family conflict, negative affect, perceived stress, and mental health in full-time female employees. We found that women’s perceptions of both work-to-family conflict and family-to-work conflict were significant negatively related to mental health. Additionally, the results showed that negative affect and perceived stress were negatively correlated with mental health. The 95% confidence intervals indicated the sequential mediating effect of negative affect and stress in the relationship between work–family conflict and mental health was significant, which supported the hypothesized sequential mediation model. The findings suggest that work–family conflicts affected the level of self-reported mental health, and this relationship functioned through the two sequential mediators of negative affect and perceived stress. PMID:29719522

  17. Work-Family Conflict and Mental Health Among Female Employees: A Sequential Mediation Model via Negative Affect and Perceived Stress.

    Science.gov (United States)

    Zhou, Shiyi; Da, Shu; Guo, Heng; Zhang, Xichao

    2018-01-01

    After the implementation of the universal two-child policy in 2016, more and more working women have found themselves caught in the dilemma of whether to raise a baby or be promoted, which exacerbates work-family conflicts among Chinese women. Few studies have examined the mediating effect of negative affect. The present study combined the conservation of resources model and affective events theory to examine the sequential mediating effect of negative affect and perceived stress in the relationship between work-family conflict and mental health. A valid sample of 351 full-time Chinese female employees was recruited in this study, and participants voluntarily answered online questionnaires. Pearson correlation analysis, structural equation modeling, and multiple mediation analysis were used to examine the relationships between work-family conflict, negative affect, perceived stress, and mental health in full-time female employees. We found that women's perceptions of both work-to-family conflict and family-to-work conflict were significant negatively related to mental health. Additionally, the results showed that negative affect and perceived stress were negatively correlated with mental health. The 95% confidence intervals indicated the sequential mediating effect of negative affect and stress in the relationship between work-family conflict and mental health was significant, which supported the hypothesized sequential mediation model. The findings suggest that work-family conflicts affected the level of self-reported mental health, and this relationship functioned through the two sequential mediators of negative affect and perceived stress.

  18. Work–Family Conflict and Mental Health Among Female Employees: A Sequential Mediation Model via Negative Affect and Perceived Stress

    Directory of Open Access Journals (Sweden)

    Shiyi Zhou

    2018-04-01

    Full Text Available After the implementation of the universal two-child policy in 2016, more and more working women have found themselves caught in the dilemma of whether to raise a baby or be promoted, which exacerbates work–family conflicts among Chinese women. Few studies have examined the mediating effect of negative affect. The present study combined the conservation of resources model and affective events theory to examine the sequential mediating effect of negative affect and perceived stress in the relationship between work–family conflict and mental health. A valid sample of 351 full-time Chinese female employees was recruited in this study, and participants voluntarily answered online questionnaires. Pearson correlation analysis, structural equation modeling, and multiple mediation analysis were used to examine the relationships between work–family conflict, negative affect, perceived stress, and mental health in full-time female employees. We found that women’s perceptions of both work-to-family conflict and family-to-work conflict were significant negatively related to mental health. Additionally, the results showed that negative affect and perceived stress were negatively correlated with mental health. The 95% confidence intervals indicated the sequential mediating effect of negative affect and stress in the relationship between work–family conflict and mental health was significant, which supported the hypothesized sequential mediation model. The findings suggest that work–family conflicts affected the level of self-reported mental health, and this relationship functioned through the two sequential mediators of negative affect and perceived stress.

  19. How far from Just-in-time are Portuguese firms? A survey of its progress and perception.

    OpenAIRE

    Maria Rosário Moreira; Rui Alves

    2006-01-01

    As competition increases, Just-in-Time (JIT) manufacturing becomes an important issue in Portuguese industry. After a brief review of its history, elements, advantages and limitations, this paper presents the results of a postal questionnaire survey about JIT system sent to a sample of manufacturing firms in Portugal, with the aim of determining the degree of development, perception and status of JIT production in Portuguese industries. The findings suggest that the surveyed firms have a basi...

  20. Consumer Food Safety Risk Attitudes and Perceptions Over Time: The Case of BSE Crisis

    NARCIS (Netherlands)

    Kalogeras, N.; Pennings, J.M.E.; Ittersum, van K.

    2009-01-01

    Recent research has shown that by decoupling the risk response behaviour of consumers into the separate components of risk perception and risk attitude, a more robust conceptualization and prediction of consumers’ reactions to food safety issues is possible. Furthermore, it has been argued that the

  1. "No Time to Play": Perceptions toward Physical Activity in Youth with Cystic Fibrosis

    Science.gov (United States)

    Moola, Fiona; Faulkner, Guy E. J.; Schneiderman, Jane E.

    2012-01-01

    Although physical activity may reduce lung function decline in youth with cystic fibrosis (CF), most patients are inactive. Little is known about why youth with CF are inactive or how to facilitate physical activity. This study explored perceptions toward physical activity in 14 youth with CF at a Canadian Hospital. Qualitative interviews were…

  2. Modeling the Time Course of Feature Perception and Feature Information Retrieval

    Science.gov (United States)

    Kent, Christopher; Lamberts, Koen

    2006-01-01

    Three experiments investigated whether retrieval of information about different dimensions of a visual object varies as a function of the perceptual properties of those dimensions. The experiments involved two perception-based matching tasks and two retrieval-based matching tasks. A signal-to-respond methodology was used in all tasks. A stochastic…

  3. Sequential Monte Carlo with Highly Informative Observations

    OpenAIRE

    Del Moral, Pierre; Murray, Lawrence M.

    2014-01-01

    We propose sequential Monte Carlo (SMC) methods for sampling the posterior distribution of state-space models under highly informative observation regimes, a situation in which standard SMC methods can perform poorly. A special case is simulating bridges between given initial and final values. The basic idea is to introduce a schedule of intermediate weighting and resampling times between observation times, which guide particles towards the final state. This can always be done for continuous-...

  4. Treatment comfort, time perception, and preference for conventional and digital impression techniques: A comparative study in young patients.

    Science.gov (United States)

    Burhardt, Lukasz; Livas, Christos; Kerdijk, Wouter; van der Meer, Wicher Joerd; Ren, Yijin

    2016-08-01

    The aim of this crossover study was to assess perceptions and preferences for impression techniques in young orthodontic patients receiving alginate and 2 different digital impressions. Thirty-eight subjects aged 10 to 17 years requiring impressions for orthodontic treatment were randomly allocated to 3 groups that differed in the order that an alginate impressions and 2 different intraoral scanning procedures were administered. After each procedure, the patients were asked to score their perceptions on a 5-point Likert scale for gag reflex, queasiness, difficulty to breathe, uncomfortable feeling, perception of the scanning time, state of anxiety, and use of a powder, and to select the preferred impression system. Chairside time and maximal mouth opening were also registered. More queasiness (P = 0.00) and discomfort (P = 0.02) during alginate impression taking of the maxilla were perceived compared with the scans with the CEREC Omnicam (Sirona Dental Systems, Bensheim, Germany). There were no significant differences in perceptions between the alginate impressions and the Lava C.O.S. (3M ESPE, St Paul, Minn) and between the 2 scanners. Chairside times for the alginate impressions (9.7 ± 1.8 minutes) and the CEREC Omnicam (10.7 ± 1.8 minutes) were significantly lower (P <0.001) than for the Lava C.O.S. (17.8 ± 4.0 minutes). Digital impressions were favored by 51% of the subjects, whereas 29% chose alginate impressions, and 20% had no preference. Regardless of the significant differences in the registered times among the 3 impression-taking methods, the distributions of the Likert scores of time perception and maximal mouth opening were similar in all 3 groups. Young orthodontic patients preferred the digital impression techniques over the alginate method, although alginate impressions required the shortest chairside time. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  5. Speech perception in older listeners with normal hearing:conditions of time alteration, selective word stress, and length of sentences.

    Science.gov (United States)

    Cho, Soojin; Yu, Jyaehyoung; Chun, Hyungi; Seo, Hyekyung; Han, Woojae

    2014-04-01

    Deficits of the aging auditory system negatively affect older listeners in terms of speech communication, resulting in limitations to their social lives. To improve their perceptual skills, the goal of this study was to investigate the effects of time alteration, selective word stress, and varying sentence lengths on the speech perception of older listeners. Seventeen older people with normal hearing were tested for seven conditions of different time-altered sentences (i.e., ±60%, ±40%, ±20%, 0%), two conditions of selective word stress (i.e., no-stress and stress), and three different lengths of sentences (i.e., short, medium, and long) at the most comfortable level for individuals in quiet circumstances. As time compression increased, sentence perception scores decreased statistically. Compared to a natural (or no stress) condition, the selectively stressed words significantly improved the perceptual scores of these older listeners. Long sentences yielded the worst scores under all time-altered conditions. Interestingly, there was a noticeable positive effect for the selective word stress at the 20% time compression. This pattern of results suggests that a combination of time compression and selective word stress is more effective for understanding speech in older listeners than using the time-expanded condition only.

  6. A novel approach to assess temporal sensory perception of muscle foods: application of a time-intensity technique to diverse Iberian meat products.

    Science.gov (United States)

    Lorido, Laura; Estévez, Mario; Ventanas, Sonia

    2014-01-01

    Although dynamic sensory techniques such as time-intensity (TI) have been applied to certain meat products, existing knowledge regarding the temporal sensory perception of muscle foods is still limited. The objective of the present study was to apply TI to the flavour and texture perception of three different Iberian meat products: liver pâté, dry-cured sausages ("salchichon") and dry-cured loin. Moreover, the advantages of using dynamic versus static sensory techniques were explored by subjecting the same products to a quantitative descriptive analysis (QDA). TI was a suitable technique to assess the impact of composition and structure of the three meat products on flavour and texture perception from a dynamic perspective. TI parameters extracted from the TI-curves and related to temporal perception enabled the detection of clear differences in sensory temporal perception between the meat products and provided additional insight on sensory perception compared to the conventional static sensory technique (QDA). © 2013.

  7. A one-sided sequential test

    Energy Technology Data Exchange (ETDEWEB)

    Racz, A.; Lux, I. [Hungarian Academy of Sciences, Budapest (Hungary). Atomic Energy Research Inst.

    1996-04-16

    The applicability of the classical sequential probability ratio testing (SPRT) for early failure detection problems is limited by the fact that there is an extra time delay between the occurrence of the failure and its first recognition. Chien and Adams developed a method to minimize this time for the case when the problem can be formulated as testing the mean value of a Gaussian signal. In our paper we propose a procedure that can be applied for both mean and variance testing and that minimizes the time delay. The method is based on a special parametrization of the classical SPRT. The one-sided sequential tests (OSST) can reproduce the results of the Chien-Adams test when applied for mean values. (author).

  8. Induction of simultaneous and sequential malolactic fermentation in durian wine.

    Science.gov (United States)

    Taniasuri, Fransisca; Lee, Pin-Rou; Liu, Shao-Quan

    2016-08-02

    This study represented for the first time the impact of malolactic fermentation (MLF) induced by Oenococcus oeni and its inoculation strategies (simultaneous vs. sequential) on the fermentation performance as well as aroma compound profile of durian wine. There was no negative impact of simultaneous inoculation of O. oeni and Saccharomyces cerevisiae on the growth and fermentation kinetics of S. cerevisiae as compared to sequential fermentation. Simultaneous MLF did not lead to an excessive increase in volatile acidity as compared to sequential MLF. The kinetic changes of organic acids (i.e. malic, lactic, succinic, acetic and α-ketoglutaric acids) varied with simultaneous and sequential MLF relative to yeast alone. MLF, regardless of inoculation mode, resulted in higher production of fermentation-derived volatiles as compared to control (alcoholic fermentation only), including esters, volatile fatty acids, and terpenes, except for higher alcohols. Most indigenous volatile sulphur compounds in durian were decreased to trace levels with little differences among the control, simultaneous and sequential MLF. Among the different wines, the wine with simultaneous MLF had higher concentrations of terpenes and acetate esters while sequential MLF had increased concentrations of medium- and long-chain ethyl esters. Relative to alcoholic fermentation only, both simultaneous and sequential MLF reduced acetaldehyde substantially with sequential MLF being more effective. These findings illustrate that MLF is an effective and novel way of modulating the volatile and aroma compound profile of durian wine. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. “It Was Raining All the Time!”: Ex Post Tourist Weather Perceptions

    Directory of Open Access Journals (Sweden)

    Stefan Gössling

    2016-01-01

    Full Text Available The importance of weather for tourism is now widely recognized. However, no research has so far addressed weather events from retrospective viewpoints, and, in particular, the role of “extreme” events in longer-term holiday memories. To better understand the character of ex post weather experiences and their importance in destination image perceptions and future travel planning behavior, this exploratory study addressed a sample of 50 tourists from three globally important source markets: Austria, Germany and Switzerland. Results indicate that weather events do not dominate long-term memories of tourist experiences. Yet, weather events are important in shaping destination image, with “rain” being the single most important weather variable negatively influencing perceptions. Results also suggest that weather events perceived as extreme can involve considerable emotions. The study of ex post traveler memories consequently makes a valuable contribution to the understanding of the complexity of “extreme weather” events for tourist demand responses.

  10. Quantum Inequalities and Sequential Measurements

    International Nuclear Information System (INIS)

    Candelpergher, B.; Grandouz, T.; Rubinx, J.L.

    2011-01-01

    In this article, the peculiar context of sequential measurements is chosen in order to analyze the quantum specificity in the two most famous examples of Heisenberg and Bell inequalities: Results are found at some interesting variance with customary textbook materials, where the context of initial state re-initialization is described. A key-point of the analysis is the possibility of defining Joint Probability Distributions for sequential random variables associated to quantum operators. Within the sequential context, it is shown that Joint Probability Distributions can be defined in situations where not all of the quantum operators (corresponding to random variables) do commute two by two. (authors)

  11. Sequential Scintigraphy in Renal Transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, K. zum; Harbst, H.; Schenck, P.; Franz, H. E.; Ritz, E.; Roehl, L.; Ziegler, M.; Ammann, W.; Maier-Borst, W. [Institut Fuer Nuklearmedizin, Deutsches Krebsforschungszentrum, Heidelberg, Federal Republic of Germany (Germany)

    1969-05-15

    Based on experience gained from more than 1600 patients with proved or suspected kidney diseases and on results on extended studies with dogs, sequential scintigraphy was performed after renal transplantation in dogs. After intravenous injection of 500 {mu}Ci. {sup 131}I-Hippuran scintiphotos were taken during the first minute with an exposure time of 15 sec each and thereafter with an exposure of 2 min up to at least 16 min.. Several examinations were evaluated digitally. 26 examinations were performed on 11 dogs with homotransplanted kidneys. Immediately after transplantation the renal function was almost normal arid the bladder was filled in due time. At the beginning of rejection the initial uptake of radioactive Hippuran was reduced. The intrarenal transport became delayed; probably the renal extraction rate decreased. Corresponding to the development of an oedema in the transplant the uptake area increased in size. In cases of thrombosis of the main artery there was no evidence of any uptake of radioactivity in the transplant. Similar results were obtained in 41 examinations on 15 persons. Patients with postoperative anuria due to acute tubular necrosis showed still some uptake of radioactivity contrary to those with thrombosis of the renal artery, where no uptake was found. In cases of rejection the most frequent signs were a reduced initial uptake and a delayed intrarenal transport of radioactive Hippuran. Infarction could be detected by a reduced uptake in distinct areas of the transplant. (author)

  12. Framework for sequential approximate optimization

    NARCIS (Netherlands)

    Jacobs, J.H.; Etman, L.F.P.; Keulen, van F.; Rooda, J.E.

    2004-01-01

    An object-oriented framework for Sequential Approximate Optimization (SAO) isproposed. The framework aims to provide an open environment for thespecification and implementation of SAO strategies. The framework is based onthe Python programming language and contains a toolbox of Python

  13. Driving under the influence among frequent ecstasy consumers in Australia: trends over time and the role of risk perceptions.

    Science.gov (United States)

    Matthews, Allison Jane; Bruno, Raimondo; Dietze, Paul; Butler, Kerryn; Burns, Lucy

    2014-11-01

    Driving under the influence (DUI) of alcohol and illicit drugs is a serious road safety concern. This research aimed to examine trends in DUI across time and changes in attitudes towards the risks (crash and legal) associated with DUI among regular ecstasy users (REU) interviewed in Australia. Participants were regular (at least monthly) ecstasy users surveyed in 2007 (n=573) or 2011 (n=429) who had driven a car in the last six months. Face to face interviews comprised questions about recent engagement of DUI and roadside breath (alcohol) and saliva (drug) testing. Participants also reported the risk of crash and of being apprehended by police if DUI of alcohol, cannabis, ecstasy, and methamphetamine. There were significant reductions in DUI of psychostimulants (ecstasy, methamphetamine, cocaine, LSD) but not alcohol or cannabis between 2007 and 2011. This was accompanied by increased experience of roadside saliva testing and increases in crash and legal risk perceptions for ecstasy and methamphetamine, but not alcohol or cannabis. When the relationship between DUI and risk variables was examined, low crash risk perceptions were associated with DUI of all substances and low legal risk perceptions were associated with DUI of ecstasy. The observed reduction in DUI of psychostimulants among frequent ecstasy consumers may be related to increased risk awareness stemming from educational campaigns and the introduction of saliva testing on Australian roads. Such countermeasures may be less effective in relation to deterring or changing attitudes towards DUI of cannabis and alcohol among this group. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Deep Time Framework: A Preliminary Study of U.K. Primary Teachers' Conceptions of Geological Time and Perceptions of Geoscience.

    Science.gov (United States)

    Trend, Roger David

    2001-01-01

    Studies (n=51) inservice school teachers with regard to their orientations toward geoscience phenomena in general and deep time in particular. Aims to identify the nature of idiosyncratic conceptions of deep time and propose a curricular Deep Time Framework for teacher education. (Contains 29 references.) (Author/YDS)

  15. Comparing two Poisson populations sequentially: an application

    International Nuclear Information System (INIS)

    Halteman, E.J.

    1986-01-01

    Rocky Flats Plant in Golden, Colorado monitors each of its employees for radiation exposure. Excess exposure is detected by comparing the means of two Poisson populations. A sequential probability ratio test (SPRT) is proposed as a replacement for the fixed sample normal approximation test. A uniformly most efficient SPRT exists, however logistics suggest using a truncated SPRT. The truncated SPRT is evaluated in detail and shown to possess large potential savings in average time spent by employees in the monitoring process

  16. Sequentially pulsed traveling wave accelerator

    Science.gov (United States)

    Caporaso, George J [Livermore, CA; Nelson, Scott D [Patterson, CA; Poole, Brian R [Tracy, CA

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  17. “History is not linear … it zigzags”: The Perception of Time in Magris' novel Blindly

    Directory of Open Access Journals (Sweden)

    Irena Prosenc Šegula

    2012-12-01

    Full Text Available In his novel Blindly Claudio Magris develops a complex perception of time. This perception is intertwined with reflections on history, identity and the status of the narrative voice. History, which “is not linear” but “zigzags” is presented as a continuously repetitive phenomenon, while temporal time is impossible to measure. The status of the autodiegetic narrator becomes highly problematic as the narrative voice assumes identities belonging to various historical periods ranging from the late 18th to the 20th centuries. The novel focuses on repressive historical periods which deform the protagonists' identities, thereby conveying an image of history as a blind and violent force. Fragmentation, one of the basic narrative techniques in the novel, concerns time sequences as well as the protagonists' identities and the narrative voice itself. As the protagonists' lives can only be narrated as fragments, there are frequent passages between different time periods. These merge into extratemporality, which is associated with eternal suffering stemming from the repetitive, oppressive nature of history. The historical events depicted in the novel are interpreted through the extratemporal dimension of the Argonaut myth.

  18. The neural time course of art perception: an ERP study on the processing of style versus content in art.

    Science.gov (United States)

    Augustin, M Dorothee; Defranceschi, Birgit; Fuchs, Helene K; Carbon, Claus-Christian; Hutzler, Florian

    2011-06-01

    A central prerequisite to understand the phenomenon of art in psychological terms is to investigate the nature of the underlying perceptual and cognitive processes. Building on a study by Augustin, Leder, Hutzler, and Carbon (2008) the current ERP study examined the neural time course of two central aspects of representational art, one of which is closely related to object- and scene perception, the other of which is art-specific: content and style. We adapted a paradigm that has repeatedly been employed in psycholinguistics and that allows one to examine the neural time course of two processes in terms of when sufficient information is available to allow successful classification. Twenty-two participants viewed pictures that systematically varied in style and content and conducted a combined go/nogo dual choice task. The dependent variables of interest were the Lateralised Readiness Potential (LRP) and the N200 effect. Analyses of both measures support the notion that in the processing of art style follows content, with style-related information being available at around 224 ms or between 40 and 94 ms later than content-related information. The paradigm used here offers a promising approach to further explore the time course of art perception, thus helping to unravel the perceptual and cognitive processes that underlie the phenomenon of art and the fascination it exerts. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. NASA Family Science Night: Changing perceptions one family at a time

    Science.gov (United States)

    Mitchell, Sara E.; Drobnes, Emilie; Sol Colina-Trujillo, M.; Noel-Storr, Jacob

    2008-12-01

    Parents and families have the greatest influence on children's attitudes towards education and career choices. If students' attitudes towards science, particularly the physical sciences, are not influenced positively by parental/familial attitudes, efforts to improve the quality of content and teaching of these subjects in school may be futile. Research shows that parental involvement increases student achievement outcomes, and family-oriented programs have a direct impact on student performance. Based on this premise, the NASA Goddard Space Flight Center started a series of Family Science Nights for middle school students and their families. The program provides a non-threatening venue for families to explore the importance of science and technology in our daily lives by engaging in learning activities that change their perception and understanding of science - making it more practical and approachable for participants of all ages. Family Science Night strives to change the way that students and their families participate in science, within the program and beyond.

  20. UNIVERSITY STUDENTS’ PERCEPTIONS OF TRANSFER OF ACADEMIC WRITING SKILLS ACROSS TIME

    Directory of Open Access Journals (Sweden)

    Tharwat EL-Sakran

    2017-03-01

    Full Text Available This study investigates university students' perceptions towards an English for advanced academic writing purposes (AAW course taught in a private university in the United Arab Emirates. It probes into the relevance of the skills taught to the students' academic disciplines. Data was gathered through a short survey administered to students who successfully completed the course. The transferability of skills was measured in light of some of the learning objectives of the AAW stated in its syllabus. Findings indicated positive students' attitudes towards the AAW course. They also revealed that some learning outcomes did transfer to students' writing tasks in their major courses. However, transfer of these skills was more noticeable in some university disciplines (e.g. English more than others (e.g. Business Administration. Detailed explanations of reasons and contexts for skill transfer are presented. This research concludes with some pedagogical recommendations and suggestions for course improvement and further research.

  1. Left insular cortex and left SFG underlie prismatic adaptation effects on time perception: evidence from fMRI.

    Science.gov (United States)

    Magnani, Barbara; Frassinetti, Francesca; Ditye, Thomas; Oliveri, Massimiliano; Costantini, Marcello; Walsh, Vincent

    2014-05-15

    Prismatic adaptation (PA) has been shown to affect left-to-right spatial representations of temporal durations. A leftward aftereffect usually distorts time representation toward an underestimation, while rightward aftereffect usually results in an overestimation of temporal durations. Here, we used functional magnetic resonance imaging (fMRI) to study the neural mechanisms that underlie PA effects on time perception. Additionally, we investigated whether the effect of PA on time is transient or stable and, in the case of stability, which cortical areas are responsible of its maintenance. Functional brain images were acquired while participants (n=17) performed a time reproduction task and a control-task before, immediately after and 30 min after PA inducing a leftward aftereffect, administered outside the scanner. The leftward aftereffect induced an underestimation of time intervals that lasted for at least 30 min. The left anterior insula and the left superior frontal gyrus showed increased functional activation immediately after versus before PA in the time versus the control-task, suggesting these brain areas to be involved in the executive spatial manipulation of the representation of time. The left middle frontal gyrus showed an increase of activation after 30 min with respect to before PA. This suggests that this brain region may play a key role in the maintenance of the PA effect over time. Copyright © 2014. Published by Elsevier Inc.

  2. Multichannel, sequential or combined X-ray spectrometry

    International Nuclear Information System (INIS)

    Florestan, J.

    1979-01-01

    X-ray spectrometer qualities and defects are evaluated for sequential and multichannel categories. Multichannel X-ray spectrometer has time-coherency advantage and its results could be more reproducible; on the other hand some spatial incoherency limits low percentage and traces applications, specially when backgrounds are very variable. In this last case, sequential X-ray spectrometer would find again great usefulness [fr

  3. Remarks on sequential designs in risk assessment

    International Nuclear Information System (INIS)

    Seidenfeld, T.

    1982-01-01

    The special merits of sequential designs are reviewed in light of particular challenges that attend risk assessment for human population. The kinds of ''statistical inference'' are distinguished and the problem of design which is pursued is the clash between Neyman-Pearson and Bayesian programs of sequential design. The value of sequential designs is discussed and the Neyman-Pearson vs. Bayesian sequential designs are probed in particular. Finally, warnings with sequential designs are considered, especially in relation to utilitarianism

  4. Perceptions of Teaching Effectiveness of Part-Time and Full-Time Clinical Nursing Faculty of BSN Education

    Science.gov (United States)

    DeSantis, Kimberly L.

    2012-01-01

    The United States faces a critical shortage of full-time registered nurses, which is . directly affected by the shortage of nurse educators. Many schools of nursing are already seeing the impact as qualified program applicants are being turned away due to the lack of qualified educators available to teach them. The trend has become to employ…

  5. Patterns and perceptions of physical activity and sedentary time in male transport drivers working in regional Australia.

    Science.gov (United States)

    Wong, Jason Y L; Gilson, Nicholas D; Bush, Robert A; Brown, Wendy J

    2014-08-01

    To objectively measure physical activity (PA) patterns and sedentary time, and explore perceptions of workplace PA opportunities in regional male transport workers. A multi-method study involving 28 drivers (52.4±9.69 years) working at a bus company in South-East Queensland, Australia. PA was measured using accelerometers (n=23) to determine the proportion of time spent in sedentary (organisational barriers (shift work and irregular driving routines), tended to preclude some drivers from engaging with these opportunities. Findings contest the notion that a sedentary occupation such as driving necessitates an inactive work environment. This research informs ongoing intervention efforts to target inactive drivers who are struggling to take advantage of existing workplace-related PA opportunities. © 2014 Public Health Association of Australia.

  6. “They Like Me, They Like Me Not”: Popularity and Adolescents’ Perceptions of Acceptance Predicting Social Functioning Over Time

    Science.gov (United States)

    McElhaney, Kathleen B.; Antonishak, Jill; Allen, Joseph P.

    2011-01-01

    This study examined the dual roles of adolescents’ perceptions of social acceptance and sociometric popularity in predicting relative changes over time in adolescents’ social functioning. Observational, self-report, and peer report data were obtained from 164 adolescents who were interviewed at age 13 years and then again at age 14 years, as well as their same-sex close friends. Adolescents who felt positively about their own social standing fared well over time, regardless of their level of sociometric popularity. Further, low popularity was particularly problematic for adolescents who failed to see themselves as fitting in. Results suggest that during adolescence, when it becomes increasingly possible for teens to choose their own social niches, it is possible to be socially successful without being broadly popular. PMID:18489423

  7. Pass-transistor asynchronous sequential circuits

    Science.gov (United States)

    Whitaker, Sterling R.; Maki, Gary K.

    1989-01-01

    Design methods for asynchronous sequential pass-transistor circuits, which result in circuits that are hazard- and critical-race-free and which have added degrees of freedom for the input signals, are discussed. The design procedures are straightforward and easy to implement. Two single-transition-time state assignment methods are presented, and hardware bounds for each are established. A surprising result is that the hardware realizations for each next state variable and output variable is identical for a given flow table. Thus, a state machine with N states and M outputs can be constructed using a single layout replicated N + M times.

  8. Sequential versus simultaneous market delineation

    DEFF Research Database (Denmark)

    Haldrup, Niels; Møllgaard, Peter; Kastberg Nielsen, Claus

    2005-01-01

    and geographical markets. Using a unique data setfor prices of Norwegian and Scottish salmon, we propose a methodologyfor simultaneous market delineation and we demonstrate that comparedto a sequential approach conclusions will be reversed.JEL: C3, K21, L41, Q22Keywords: Relevant market, econometric delineation......Delineation of the relevant market forms a pivotal part of most antitrustcases. The standard approach is sequential. First the product marketis delineated, then the geographical market is defined. Demand andsupply substitution in both the product dimension and the geographicaldimension...

  9. Sequential logic analysis and synthesis

    CERN Document Server

    Cavanagh, Joseph

    2007-01-01

    Until now, there was no single resource for actual digital system design. Using both basic and advanced concepts, Sequential Logic: Analysis and Synthesis offers a thorough exposition of the analysis and synthesis of both synchronous and asynchronous sequential machines. With 25 years of experience in designing computing equipment, the author stresses the practical design of state machines. He clearly delineates each step of the structured and rigorous design principles that can be applied to practical applications. The book begins by reviewing the analysis of combinatorial logic and Boolean a

  10. Perceptions of part-time faculty by chairpersons of undergraduate health education programs.

    Science.gov (United States)

    Price, James H; Braun, Robert E; McKinney, Molly A; Thompson, Amy

    2011-11-01

    In recent years, it has become commonplace for universities to hire part-time and non-tenure track faculty to save money. This study examined how commonly part-time faculty are used in health education and how they are used to meet program needs. The American Association of Health Education's 2009 "Directory of Institutions Offering Undergraduate and Graduate Degree Programs in Health Education" was used to send a three-wave mailing to programs that were not schools of public health (n = 215). Of the 125 departments (58%) that responded, those that used part-time faculty averaged 7.5 part-time faculty in the previous academic year, teaching on average a total of 10 classes per year. A plurality of departments (38%) were currently using more part-time faculty than 10 years ago and 33% perceived that the number of part-time faculty has resulted in decreases in the number of full-time positions. Although 77% of department chairs claimed they would prefer to replace all of their part-time faculty with one full-time tenure track faculty member. As colleges downsize, many health education programs are using more part-time faculty. Those faculty members who take part-time positions will likely be less involved in academic activities than their full-time peers. Thus, further research is needed on the effects of these changes on the quality of health education training and department productivity.

  11. A pilot study into the perception of unreliability of travel times using in-depth interviews

    NARCIS (Netherlands)

    Tseng, Y.-Y.; Verhoef, E.; de Jong, G.; Kouwenhoven, M.; van der Hoorn, T.

    2009-01-01

    Transport investments normally reduce travel times, but may also reduce unreliability. Conventional time gains can be evaluated in cost benefit analysis using standard values of time. For valuing reliability gains, however, no standard measures are readily available. The Dutch Ministry of Transport

  12. Absence of both auditory evoked potentials and auditory percepts dependent on timing cues.

    Science.gov (United States)

    Starr, A; McPherson, D; Patterson, J; Don, M; Luxford, W; Shannon, R; Sininger, Y; Tonakawa, L; Waring, M

    1991-06-01

    An 11-yr-old girl had an absence of sensory components of auditory evoked potentials (brainstem, middle and long-latency) to click and tone burst stimuli that she could clearly hear. Psychoacoustic tests revealed a marked impairment of those auditory perceptions dependent on temporal cues, that is, lateralization of binaural clicks, change of binaural masked threshold with changes in signal phase, binaural beats, detection of paired monaural clicks, monaural detection of a silent gap in a sound, and monaural threshold elevation for short duration tones. In contrast, auditory functions reflecting intensity or frequency discriminations (difference limens) were only minimally impaired. Pure tone audiometry showed a moderate (50 dB) bilateral hearing loss with a disproportionate severe loss of word intelligibility. Those auditory evoked potentials that were preserved included (1) cochlear microphonics reflecting hair cell activity; (2) cortical sustained potentials reflecting processing of slowly changing signals; and (3) long-latency cognitive components (P300, processing negativity) reflecting endogenous auditory cognitive processes. Both the evoked potential and perceptual deficits are attributed to changes in temporal encoding of acoustic signals perhaps occurring at the synapse between hair cell and eighth nerve dendrites. The results from this patient are discussed in relation to previously published cases with absent auditory evoked potentials and preserved hearing.

  13. Group-sequential analysis may allow for early trial termination

    DEFF Research Database (Denmark)

    Gerke, Oke; Vilstrup, Mie H; Halekoh, Ulrich

    2017-01-01

    BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG-PET/CT mea......BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG...... assumed to be normally distributed, and sequential one-sided hypothesis tests on the population standard deviation of the differences against a hypothesised value of 1.5 were performed, employing an alpha spending function. The fixed-sample analysis (N = 45) was compared with the group-sequential analysis...... strategies comprising one (at N = 23), two (at N = 15, 30), or three interim analyses (at N = 11, 23, 34), respectively, which were defined post hoc. RESULTS: When performing interim analyses with one third and two thirds of patients, sufficient agreement could be concluded after the first interim analysis...

  14. Patient perceptions regarding physician reimbursements, wait times, and out-of-pocket payments for anterior cruciate ligament reconstruction in Ontario.

    Science.gov (United States)

    Memon, Muzammil; Ginsberg, Lydia; de Sa, Darren; Nashed, Andrew; Simunovic, Nicole; Phillips, Mark; Denkers, Matthew; Ogilvie, Rick; Peterson, Devin; Ayeni, Olufemi R

    2017-12-01

    Currently, there is a lack of knowledge regarding patient perceptions surrounding physician reimbursements, appropriate wait times, and out-of-pocket payment options for anterior cruciate ligament reconstruction (ACLR). Our objective was to determine the current state of these perceptions in an Ontario setting. A survey was developed and pretested to address patient perceptions about physician reimbursements, appropriate wait times, and out-of-pocket payment options for ACLR using a focus group of experts and by reviewing prior surveys. The survey was administered to patients in a waiting room setting. Two hundred and fifty completed surveys were obtained (79.9% response rate). Participants responded that an appropriate physician reimbursement for ACLR was $1000.00 and that the Ontario Health Insurance Plan (OHIP) reimbursed physicians $700.00 for ACLR. Seventy-four percent of participants responded that the OHIP reimbursement of $615.20 for the procedure was either lower or much lower than what they considered to be an appropriate reimbursement for ACLR. Over 90% of participants responded that an ACLR should occur within 90 days of injury. Thirty-five percent of participants were willing to pay $750.00 out-of-pocket to have an ACLR done sooner, while 16.4% of participants were willing to pay $2500.00 out-of-pocket to travel outside of Canada for expedited surgery. This survey study demonstrates that patients' estimates of both appropriate and actual physician reimbursements were greater than the current reimbursement for ACLR. Further, the majority of individuals report that the surgical fee for ACLR is lower than what they consider to be an appropriate amount of compensation for the procedure. Additionally, nearly all respondents believe that a ruptured ACL should be reconstructed within 90 days of injury. Consequently, a number of patients are willing to pay out-of-pocket for expedited surgery either in Canada or abroad. However, patients' preferences for

  15. Detection of anorectal and cervicovaginal Chlamydia trachomatis infections following azithromycin treatment: prospective cohort study with multiple time-sequential measures of rRNA, DNA, quantitative load and symptoms.

    Directory of Open Access Journals (Sweden)

    Nicole H T M Dukers-Muijrers

    Full Text Available Determination of Chlamydia trachomatis (Ct treatment success is hampered by current assessment methods, which involve a single post-treatment measurement only. Therefore, we evaluated Ct detection by applying multiple laboratory measures on time-sequential post-treatment samples.A prospective cohort study was established with azithromycin-treated (1000 mg Ct patients (44 cervicovaginal and 15 anorectal cases. Each patient provided 18 self-taken samples pre-treatment and for 8 weeks post-treatment (response: 96%; 1,016 samples. Samples were tested for 16S rRNA (TMA, bacterial load (quantitative PCR; Chlamydia plasmid DNA and type (serovar and multilocus sequence typing. Covariates (including behavior, pre-treatment load, anatomic site, symptoms, age, and menstruation were tested for their potential association with positivity and load at 3-8 weeks using regression analyses controlling for repeated measures.By day 9, Ct positivity decreased to 20% and the median load to 0.3 inclusion-forming units (IFU per ml (pre-treatment: 170 IFU/ml. Of the 35 cases who reported no sex, sex with a treated partner or safe sex with a new partner, 40% had detection, i.e. one or more positive samples from 3-8 weeks (same Ct type over time, indicating possible antimicrobial treatment failure. Cases showed intermittent positive detection and the number of positive samples was higher in anorectal cases than in cervicovaginal cases. The highest observed bacterial load between 3-8 weeks post-treatment was 313 IFU/ml, yet the majority (65% of positive samples showed a load of ≤ 2 IFU/ml. Pre-treatment load was found to be associated with later load in anorectal cases.A single test at 3-8 weeks post-treatment frequently misses Ct. Detection reveals intermittent low loads, with an unknown risk of later complications or transmission. These findings warrant critical re-evaluation of the clinical management of single dose azithromycin-treated Ct patients and fuel the debate

  16. Advances in sequential data assimilation and numerical weather forecasting: An Ensemble Transform Kalman-Bucy Filter, a study on clustering in deterministic ensemble square root filters, and a test of a new time stepping scheme in an atmospheric model

    Science.gov (United States)

    Amezcua, Javier

    This dissertation deals with aspects of sequential data assimilation (in particular ensemble Kalman filtering) and numerical weather forecasting. In the first part, the recently formulated Ensemble Kalman-Bucy (EnKBF) filter is revisited. It is shown that the previously used numerical integration scheme fails when the magnitude of the background error covariance grows beyond that of the observational error covariance in the forecast window. Therefore, we present a suitable integration scheme that handles the stiffening of the differential equations involved and doesn't represent further computational expense. Moreover, a transform-based alternative to the EnKBF is developed: under this scheme, the operations are performed in the ensemble space instead of in the state space. Advantages of this formulation are explained. For the first time, the EnKBF is implemented in an atmospheric model. The second part of this work deals with ensemble clustering, a phenomenon that arises when performing data assimilation using of deterministic ensemble square root filters in highly nonlinear forecast models. Namely, an M-member ensemble detaches into an outlier and a cluster of M-1 members. Previous works may suggest that this issue represents a failure of EnSRFs; this work dispels that notion. It is shown that ensemble clustering can be reverted also due to nonlinear processes, in particular the alternation between nonlinear expansion and compression of the ensemble for different regions of the attractor. Some EnSRFs that use random rotations have been developed to overcome this issue; these formulations are analyzed and their advantages and disadvantages with respect to common EnSRFs are discussed. The third and last part contains the implementation of the Robert-Asselin-Williams (RAW) filter in an atmospheric model. The RAW filter is an improvement to the widely popular Robert-Asselin filter that successfully suppresses spurious computational waves while avoiding any distortion

  17. Evaluation Using Sequential Trials Methods.

    Science.gov (United States)

    Cohen, Mark E.; Ralls, Stephen A.

    1986-01-01

    Although dental school faculty as well as practitioners are interested in evaluating products and procedures used in clinical practice, research design and statistical analysis can sometimes pose problems. Sequential trials methods provide an analytical structure that is both easy to use and statistically valid. (Author/MLW)

  18. Attack Trees with Sequential Conjunction

    NARCIS (Netherlands)

    Jhawar, Ravi; Kordy, Barbara; Mauw, Sjouke; Radomirović, Sasa; Trujillo-Rasua, Rolando

    2015-01-01

    We provide the first formal foundation of SAND attack trees which are a popular extension of the well-known attack trees. The SAND at- tack tree formalism increases the expressivity of attack trees by intro- ducing the sequential conjunctive operator SAND. This operator enables the modeling of

  19. Effects of Scheduling Perceptions on Attitudes and Mobility in Different Part-Time Employee Types

    Science.gov (United States)

    Wittmer, Jenell L. S.; Martin, James E.

    2011-01-01

    Recent research supports the existence of a typology of part-time employees with demographic and behavioral differences. This research suggests that part-timers should not be viewed as one homogenous group and that certain part-time employee groups have fixed external role attachments, while others have more flexible attachments. Applying the…

  20. Gravity in the Brain as a Reference for Space and Time Perception.

    Science.gov (United States)

    Lacquaniti, Francesco; Bosco, Gianfranco; Gravano, Silvio; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Zago, Myrka

    2015-01-01

    Moving and interacting with the environment require a reference for orientation and a scale for calibration in space and time. There is a wide variety of environmental clues and calibrated frames at different locales, but the reference of gravity is ubiquitous on Earth. The pull of gravity on static objects provides a plummet which, together with the horizontal plane, defines a three-dimensional Cartesian frame for visual images. On the other hand, the gravitational acceleration of falling objects can provide a time-stamp on events, because the motion duration of an object accelerated by gravity over a given path is fixed. Indeed, since ancient times, man has been using plumb bobs for spatial surveying, and water clocks or pendulum clocks for time keeping. Here we review behavioral evidence in favor of the hypothesis that the brain is endowed with mechanisms that exploit the presence of gravity to estimate the spatial orientation and the passage of time. Several visual and non-visual (vestibular, haptic, visceral) cues are merged to estimate the orientation of the visual vertical. However, the relative weight of each cue is not fixed, but depends on the specific task. Next, we show that an internal model of the effects of gravity is combined with multisensory signals to time the interception of falling objects, to time the passage through spatial landmarks during virtual navigation, to assess the duration of a gravitational motion, and to judge the naturalness of periodic motion under gravity.

  1. Stimulus repetition and the perception of time: the effects of prior exposure on temporal discrimination, judgment, and production.

    Directory of Open Access Journals (Sweden)

    William J Matthews

    Full Text Available It has been suggested that repeated stimuli have shorter subjective duration than novel items, perhaps because of a reduction in the neural response to repeated presentations of the same object. Five experiments investigated the effects of repetition on time perception and found further evidence that immediate repetition reduces apparent duration, consistent with the idea that subjective duration is partly based on neural coding efficiency. In addition, the experiments found (a no effect of repetition on the precision of temporal discrimination, (b that the effects of repetition disappeared when there was a modest lag between presentations, (c that, across participants, the size of the repetition effect correlated with temporal discrimination, and (d that the effects of repetition suggested by a temporal production task were the opposite of those suggested by temporal judgments. The theoretical and practical implications of these results are discussed.

  2. The influence of real-time rural transit tracking on traveler perception.

    Science.gov (United States)

    2013-03-01

    Public transportation systems require accurate and reliable information as part of their : day-to-day operations and are increasingly engaging their customers through a variety of online : services and smart phone applications, such as real-time vehi...

  3. Time perception and depressive realism: judgment type, psychophysical functions and bias.

    Directory of Open Access Journals (Sweden)

    Diana E Kornbrot

    Full Text Available The effect of mild depression on time estimation and production was investigated. Participants made both magnitude estimation and magnitude production judgments for five time intervals (specified in seconds from 3 sec to 65 sec. The parameters of the best fitting psychophysical function (power law exponent, intercept, and threshold were determined individually for each participant in every condition. There were no significant effects of mood (high BDI, low BDI or judgment (estimation, production on the mean exponent, n = .98, 95% confidence interval (.96-1.04 or on the threshold. However, the intercept showed a 'depressive realism' effect, where high BDI participants had a smaller deviation from accuracy and a smaller difference between estimation and judgment than low BDI participants. Accuracy bias was assessed using three measures of accuracy: difference, defined as psychological time minus physical time, ratio, defined as psychological time divided by physical time, and a new logarithmic accuracy measure defined as ln (ratio. The ln (ratio measure was shown to have approximately normal residuals when subjected to a mixed ANOVA with mood as a between groups explanatory factor and judgment and time category as repeated measures explanatory factors. The residuals of the other two accuracy measures flagrantly violated normality. The mixed ANOVAs of accuracy also showed a strong depressive realism effect, just like the intercepts of the psychophysical functions. There was also a strong negative correlation between estimation and production judgments. Taken together these findings support a clock model of time estimation, combined with additional cognitive mechanisms to account for the depressive realism effect. The findings also suggest strong methodological recommendations.

  4. Time perception and depressive realism: judgment type, psychophysical functions and bias.

    Science.gov (United States)

    Kornbrot, Diana E; Msetfi, Rachel M; Grimwood, Melvyn J

    2013-01-01

    The effect of mild depression on time estimation and production was investigated. Participants made both magnitude estimation and magnitude production judgments for five time intervals (specified in seconds) from 3 sec to 65 sec. The parameters of the best fitting psychophysical function (power law exponent, intercept, and threshold) were determined individually for each participant in every condition. There were no significant effects of mood (high BDI, low BDI) or judgment (estimation, production) on the mean exponent, n = .98, 95% confidence interval (.96-1.04) or on the threshold. However, the intercept showed a 'depressive realism' effect, where high BDI participants had a smaller deviation from accuracy and a smaller difference between estimation and judgment than low BDI participants. Accuracy bias was assessed using three measures of accuracy: difference, defined as psychological time minus physical time, ratio, defined as psychological time divided by physical time, and a new logarithmic accuracy measure defined as ln (ratio). The ln (ratio) measure was shown to have approximately normal residuals when subjected to a mixed ANOVA with mood as a between groups explanatory factor and judgment and time category as repeated measures explanatory factors. The residuals of the other two accuracy measures flagrantly violated normality. The mixed ANOVAs of accuracy also showed a strong depressive realism effect, just like the intercepts of the psychophysical functions. There was also a strong negative correlation between estimation and production judgments. Taken together these findings support a clock model of time estimation, combined with additional cognitive mechanisms to account for the depressive realism effect. The findings also suggest strong methodological recommendations.

  5. Time Perception and Depressive Realism: Judgment Type, Psychophysical Functions and Bias

    OpenAIRE

    Kornbrot, Diana E.; Msetfi, Rachel M.; Grimwood, Melvyn J.

    2013-01-01

    peer-reviewed The effect of mild depression on time estimation and production was investigated. Participants made both magnitude estimation and magnitude production judgments for five time intervals (specified in seconds) from 3 sec to 65 sec. The parameters of the best fitting psychophysical function (power law exponent, intercept, and threshold) were determined individually for each participant in every condition. There were no significant effects of mood (high BDI, low BDI) or judgment ...

  6. The Perception of Time Is Underestimated in Adolescents With Anorexia Nervosa

    Directory of Open Access Journals (Sweden)

    Carmelo M. Vicario

    2018-04-01

    Full Text Available Research has revealed reduced temporal discounting (i.e., increased capacity to delay reward and altered interoceptive awareness in anorexia nervosa (AN. In line with the research linking temporal underestimation with a reduced tendency to devalue a reward and reduced interoceptive awareness, we tested the hypothesis that time duration might be underestimated in AN. Our findings revealed that patients with AN displayed lower timing accuracy in the form of timing underestimation compared with controls. These results were not predicted by clinical, demographic factors, attention, and working memory performance of the participants. The evidence of a temporal underestimation bias in AN might be clinically relevant to explain their abnormal motivation in pursuing a long-term restrictive diet, in line with the evidence that increasing the subjective temporal proximity of remote future goals can boost motivation and the actual behavior to reach them.

  7. The Perception of Time Is Underestimated in Adolescents With Anorexia Nervosa.

    Science.gov (United States)

    Vicario, Carmelo M; Felmingham, Kim

    2018-01-01

    Research has revealed reduced temporal discounting (i.e., increased capacity to delay reward) and altered interoceptive awareness in anorexia nervosa (AN). In line with the research linking temporal underestimation with a reduced tendency to devalue a reward and reduced interoceptive awareness, we tested the hypothesis that time duration might be underestimated in AN. Our findings revealed that patients with AN displayed lower timing accuracy in the form of timing underestimation compared with controls. These results were not predicted by clinical, demographic factors, attention, and working memory performance of the participants. The evidence of a temporal underestimation bias in AN might be clinically relevant to explain their abnormal motivation in pursuing a long-term restrictive diet, in line with the evidence that increasing the subjective temporal proximity of remote future goals can boost motivation and the actual behavior to reach them.

  8. Iqbal’s Ideas Regarding the New Perceptions of Space and Time

    Directory of Open Access Journals (Sweden)

    Azizan Baharuddin

    2002-12-01

    Full Text Available In the context of Islam the subject of science and belief has always been part of its élan vital. From hundreds of Qur’ānic verses, Muslim scholars and thinkers have embarked on the exercise to understand scripture in the light of His creation (the study of nature or science. When talking about space and time in the empirical and spiritual sense it is indeed these "signs" that Iqbal was interested in. This paper presents some of the ideas Iqbal had elaborated upon regarding religion and science especially on the subject of the meaning and spiritual implications of the concepts of space and time.

  9. Parent Perceptions of Time Spent Meaningfully by Young Adults with Pervasive Support Needs

    Science.gov (United States)

    Rossetti, Zachary; Lehr, Donna; Lederer, Leslie; Pelerin, Dana; Huang, Shuoxi

    2015-01-01

    This article describes a qualitative study that examined how 23 young adults with pervasive support needs and limited functional communication spent their time and how their parents (n = 23) and direct support professionals (DSPs; n = 2) defined meaningfulness in relation to the young adults' experiences. Data were collected through…

  10. Using Part-Time Working to Support Graduate Employment: Needs and Perceptions of Employers

    Science.gov (United States)

    Evans, Carl; Maxfield, Tim; Gbadamosi, Gbolahan

    2015-01-01

    An exploration of the value attached to the work experience of graduates, and particularly the value of part-time working whilst studying for a degree, from an employer's perspective, is reported. A documentary analysis of graduate recruiters was conducted to assess the extent to which work experience was specified for graduate employment…

  11. Mothers' Perception and Practice in Their Childs' Out of School [Summer] Time: A Socioeconomic Perspective

    Science.gov (United States)

    Milhomme, Marcy B.

    2014-01-01

    I set out to explore the question: How do middle-class, working-class and low-income mothers experience their children's out of school summer time? Using qualitative basic interpretive approach, study findings draw from interview data, journal entries and participant observations from a study completed with 22 mothers of varying socioeconomic…

  12. Today was yesterday tomorrow. The perception of time and the acquisition of language

    Directory of Open Access Journals (Sweden)

    Soraya Cortiñas Ansoar

    2012-12-01

    Full Text Available Temporal expressions present many problems regarding their conceptualization. Temporal deixis grammaticalises the relationship between the time of the situation described and the time of the deictic context, and its acquisition is essential in order to achieve a good command of the language. From a descriptive, linguistic and pragmatic perspective, and adopting a mixed methodology that integrates both qualitative and quantitative methods, the present paper provides a comprehensive study of the time markers that children use in the early years of their lives. More specifically, verbal forms (morphemes of time, subordinators, temporal adverbs and lexical expressions have been examined. Data for the present paper have been drawn from the Koiné corpus of child language, a corpus created at the University of Santiago de Compostela, and coordinated by Milagros Fernández Pérez. In particular, the interventions of two informants have been selected for analysis (1 boy and 1 girl between 2 and 4 years. The objectives pursued reflect the need to characterize expressions and temporal markers in child language. The results reveal the distinction and characterization of different acquisition stages in which we can observe how children use linguistic resources to acquire temporal discursive coordinates.

  13. Beliefs and Perceptions about the Future: A Measurement of Future Time Perspective

    Science.gov (United States)

    Husman, Jenefer; Shell, Duane F.

    2008-01-01

    Human's ability to consider the future, willingness to make sacrifices in the present to obtain something better in the future has been a significant part of our success as a species (Suddendorf, T., & Corballis, M. C. (1997). "Mental time travel and the evolution of the human mind." "Genetic, social, and general psychology monographs" 123,…

  14. Time 's picturing of HIV/Aids: International perceptions of disease in ...

    African Journals Online (AJOL)

    doxiconic process” as suggested by Dana Cloud and that the (visual) rhetoric of HIV/Aids has many similarities to what she sees as a culture clash in the rhetoric of the (American) war on terrorism. Key Words: Time, representation of HIV/Aids, race ...

  15. The difference between the perception of absolute and relative motion: A reaction time study

    NARCIS (Netherlands)

    J.B.J. Smeets (Jeroen); E. Brenner (Eli)

    1994-01-01

    textabstractWe used a reaction-time paradigm to examine the extent to which motion detection depends on relative motion. In the absence of relative motion, the responses could be described by a simple model based on the detection of a fixed change in position. If relative motion was present, the

  16. Participants' Perceptions on the Use of Wearable Devices to Reduce Sitting Time: Qualitative Analysis.

    Science.gov (United States)

    Takemoto, Michelle; Lewars, Brittany; Hurst, Samantha; Crist, Katie; Nebeker, Camille; Madanat, Hala; Nichols, Jeanne; Rosenberg, Dori E; Kerr, Jacqueline

    2018-03-31

    Recent epidemiological evidence indicates that, on average, people are sedentary for approximately 7.7 hours per day. There are deleterious effects of prolonged sedentary behavior that are separate from participation in physical activity and include increased risk of weight gain, cancer, metabolic syndrome, diabetes, and heart disease. Previous trials have used wearable devices to increase physical activity in studies; however, additional research is needed to fully understand how this technology can be used to reduce sitting time. The purpose of this study was to explore the potential of wearable devices as an intervention tool in a larger sedentary behavior study through a general inductive and deductive analysis of focus group discussions. We conducted four focus groups with 15 participants to discuss 7 different wearable devices with sedentary behavior capabilities. Participants recruited for the focus groups had previously participated in a pilot intervention targeting sedentary behavior over a 3-week period and were knowledgeable about the challenges of reducing sitting time. During the focus groups, participants commented on the wearability, functionality, and feedback mechanism of each device and then identified their two favorite and two least favorite devices. Finally, participants designed and described their ideal or dream wearable device. Two researchers, who have expertise analyzing qualitative data, coded and analyzed the data from the focus groups. A thematic analysis approach using Dedoose software (SocioCultural Research Consultants, LLC version 7.5.9) guided the organization of themes that reflected participants' perspectives. Analysis resulted in 14 codes that we grouped into themes. Three themes emerged from our data: (1) features of the device, (2) data the device collected, and (3) how data are displayed. Current wearable devices for increasing physical activity are insufficient to intervene on sitting time. This was especially evident when

  17. Time perception of action photographs is more precise than that of still photographs.

    Science.gov (United States)

    Moscatelli, Alessandro; Polito, Laura; Lacquaniti, Francesco

    2011-04-01

    A photograph of an action contains implicit information about the depicted motion. Previous studies using either psychophysics or neuroimaging suggested that the neural processing of implied-motion images shares some features of real-motion processing. According to the hypothesis that the target depicted in photographs with implied motion is mentally represented as continuing in motion, such kind of photographs should be processed by the brain similarly to the individual frames of a running movie. In order to decode the functional significance of a movie, we must be able to estimate the duration of each frame and the time interval between successive frames as precisely as possible. Therefore, under naturalistic conditions, one would expect that the precision of time duration estimates is higher for action pictures than for still pictures. To test this prediction, we asked human observers to compare the variable duration of test photographs with the reference duration of their scrambled version. We found that, as expected, the duration of photographs with implied motion was discriminated better than the duration of photographs without implied motion. We also found that the average reaction time for the discrimination of photographs with implied motion was longer than that for photographs without implied motion, suggesting that the processing of implied motion involves longer and/or slower neural routes to compute time duration. This longer processing may depend on the engagement of two visual systems in parallel, one for processing form and the other one for processing implied motion. The perceptual decision about time duration would occur after the convergence of signals from these two pathways.

  18. Real-time detection and discrimination of visual perception using electrocorticographic signals

    Science.gov (United States)

    Kapeller, C.; Ogawa, H.; Schalk, G.; Kunii, N.; Coon, W. G.; Scharinger, J.; Guger, C.; Kamada, K.

    2018-06-01

    Objective. Several neuroimaging studies have demonstrated that the ventral temporal cortex contains specialized regions that process visual stimuli. This study investigated the spatial and temporal dynamics of electrocorticographic (ECoG) responses to different types and colors of visual stimulation that were presented to four human participants, and demonstrated a real-time decoder that detects and discriminates responses to untrained natural images. Approach. ECoG signals from the participants were recorded while they were shown colored and greyscale versions of seven types of visual stimuli (images of faces, objects, bodies, line drawings, digits, and kanji and hiragana characters), resulting in 14 classes for discrimination (experiment I). Additionally, a real-time system asynchronously classified ECoG responses to faces, kanji and black screens presented via a monitor (experiment II), or to natural scenes (i.e. the face of an experimenter, natural images of faces and kanji, and a mirror) (experiment III). Outcome measures in all experiments included the discrimination performance across types based on broadband γ activity. Main results. Experiment I demonstrated an offline classification accuracy of 72.9% when discriminating among the seven types (without color separation). Further discrimination of grey versus colored images reached an accuracy of 67.1%. Discriminating all colors and types (14 classes) yielded an accuracy of 52.1%. In experiment II and III, the real-time decoder correctly detected 73.7% responses to face, kanji and black computer stimuli and 74.8% responses to presented natural scenes. Significance. Seven different types and their color information (either grey or color) could be detected and discriminated using broadband γ activity. Discrimination performance maximized for combined spatial-temporal information. The discrimination of stimulus color information provided the first ECoG-based evidence for color-related population

  19. Waiting for the Unicorn: Perception of Time and History in Early Chinese Writings

    OpenAIRE

    Gibas, Piotr Pawel

    2009-01-01

    In this dissertation I examine temporality as conceived in early Chinese historiography, through a systematic examination of four key works: the Mozi, the Zuozhuan, the Rishu;, and the Chu Silk Manuscript, all of them written during 4th through 1st century BCE. Each presents from a different perspective ideas about the mechanism of time and history. While only the Zuozhuan is commonly categorized as historical narrative, all four of these texts depend on records of the past to convey their wo...

  20. Speech perception at positive signal-to-noise ratios using adaptive adjustment of time compression.

    Science.gov (United States)

    Schlueter, Anne; Brand, Thomas; Lemke, Ulrike; Nitzschner, Stefan; Kollmeier, Birger; Holube, Inga

    2015-11-01

    Positive signal-to-noise ratios (SNRs) characterize listening situations most relevant for hearing-impaired listeners in daily life and should therefore be considered when evaluating hearing aid algorithms. For this, a speech-in-noise test was developed and evaluated, in which the background noise is presented at fixed positive SNRs and the speech rate (i.e., the time compression of the speech material) is adaptively adjusted. In total, 29 younger and 12 older normal-hearing, as well as 24 older hearing-impaired listeners took part in repeated measurements. Younger normal-hearing and older hearing-impaired listeners conducted one of two adaptive methods which differed in adaptive procedure and step size. Analysis of the measurements with regard to list length and estimation strategy for thresholds resulted in a practical method measuring the time compression for 50% recognition. This method uses time-compression adjustment and step sizes according to Versfeld and Dreschler [(2002). J. Acoust. Soc. Am. 111, 401-408], with sentence scoring, lists of 30 sentences, and a maximum likelihood method for threshold estimation. Evaluation of the procedure showed that older participants obtained higher test-retest reliability compared to younger participants. Depending on the group of listeners, one or two lists are required for training prior to data collection.

  1. Robustness of the Sequential Lineup Advantage

    Science.gov (United States)

    Gronlund, Scott D.; Carlson, Curt A.; Dailey, Sarah B.; Goodsell, Charles A.

    2009-01-01

    A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup…

  2. Sequential Probability Ration Tests : Conservative and Robust

    NARCIS (Netherlands)

    Kleijnen, J.P.C.; Shi, Wen

    2017-01-01

    In practice, most computers generate simulation outputs sequentially, so it is attractive to analyze these outputs through sequential statistical methods such as sequential probability ratio tests (SPRTs). We investigate several SPRTs for choosing between two hypothesized values for the mean output

  3. Random sequential adsorption of cubes

    Science.gov (United States)

    Cieśla, Michał; Kubala, Piotr

    2018-01-01

    Random packings built of cubes are studied numerically using a random sequential adsorption algorithm. To compare the obtained results with previous reports, three different models of cube orientation sampling were used. Also, three different cube-cube intersection algorithms were tested to find the most efficient one. The study focuses on the mean saturated packing fraction as well as kinetics of packing growth. Microstructural properties of packings were analyzed using density autocorrelation function.

  4. Current neurosurgical trainees' perception of the European Working Time Directive and shift work.

    Science.gov (United States)

    Tait, M J; Fellows, G A; Pushpananthan, S; Sergides, Y; Papadopoulos, M C; Bell, B A

    2008-02-01

    The introduction of the shift system in response to the European Working Time Directive has had an enormous impact on the running of neurosurgical units in the UK. This study seeks to establish what provisions are currently in place for out of hours cover and what has been the effect of the introduction of shifts in three main areas: patient safety, training and 'work/life balance'. The on-call registrar at each UK neurosurgical unit was contacted by telephone. Data regarding current emergency provision were sought. Registrars who had worked both on-calls and the shift system during their career as a neurosurgical registrar were asked to make a comparison. Data were collected from all 33 UK units. Twenty-two still use a traditional 24-h on-call system. Twenty-one on-call rotas were classed as non-resident although 12/21 of those officially on non-resident rotas were in fact resident whilst on call. Twenty-two registrars had worked both systems as a neurosurgical registrar. Twenty-one (95.45%) felt that traditional on-calls gave better clinical exposure. Twenty-one (95.45%) felt that on-calls allowed the provision of better patient care. Nineteen (86.36%) felt that on-calls were safer. Thirteen (59.09%) reported that they were more tired when doing shift work than on-calls. Fourteen (63.63%) found that the on-call system gives more useful spare time and more time to deal with family commitments. Current neurosurgery registrars feel the shift system is less safe, harmful to training and worse in terms of work/life balance. More than one-third of units are claiming to have non-resident on-call systems in order to appear compliant with EWTD when registrars are in fact resident.

  5. Human perception of the measurement of a network attack taxonomy in near real-time

    CSIR Research Space (South Africa)

    van Heerden, R

    2014-07-01

    Full Text Available apparent long after an attack and even then it is sometimes only speculation. For example, the Aggressor can not be determined in a near real-time environment and for some attacks the real power behind the attack is never determined or proven. 2.1 Actor...- tigating the accuracy of various assessment methods. We classify each class as either defined, high, low or not quantifiable. For example, it may not be possi- ble to determine the instigator of an attack (Aggressor), but only that the attack has been...

  6. Impact of orocecal transit time on patient´s perception of lactose intolerance.

    Science.gov (United States)

    Casellas, Francesc; Aparici, Anna; Casaus, Maite; Rodríguez, Purificación; Malagelada, Juan R

    2013-01-01

    symptoms attributed to the lactose intolerance are an important public health issue because of their prevalence and social relevance. Also because they may cause undue rejection of dairy products consume with potential health consequences. Transit time is a putative factor implied in the severity of symptoms associated with lactose. to elucidate the relation between orocecal transit time (OCTT) and lactose intolerance symptoms. observational study in patients referred to a lactose hydrogen breath test who showed an increase in breath H2 excretion higher than 25 ppm. OCTT was measured with the breath test and symptoms of lactose tolerance with a validated scale. Symptoms were measured twice: before receiving the lactose, inquiring about self perceived symptoms when patients consumed dairy products at home ("home symptoms"), and again after completing the lactose breath test ("test symptoms"). 161 patients were included. There was no correlation between OCTT and home symptoms (r = -0.1). When OCTT was faster than 60 minutes, intensity of "test symptoms" was similar to "home symptoms". However, in patients with normal or slow OCTT, the "home symptoms" were more intense than the "test symptoms" (p lactose test load the symptoms were proportionately more intense with faster OCTT. in lactose maldigesters, selfreported symptoms of lactose intolerance are more pronounced at home than after a high lactose challenge. Intolerance symptoms that patients attributed to lactose consume at home are due to factors other than fast OCTT.

  7. Time perception and illness acceptance among remitting-relapsing multiple sclerosis patients under treatment.

    Science.gov (United States)

    Król, Joanna; Szcześniak, Małgorzata; Koziarska, Dorota; Rzepa, Teresa

    2015-01-01

    The aim of the study was to determine temporal orientation in patients diagnosed with RR-MS as compared with that of healthy individuals; to analyse self-evaluated acceptance levels in terms of physical and psychological condition and self-reliance; an attempt to identify factors of illness acceptance in patients with RR-MS including temporal perspective. Acceptance of Illness Scale (AIS, adapted into Polish by Z. Juczyński), Zimbardo Time Perspective Inventory (ZTPI, adapted into Polish by M. Mażewski), and original interview aimed to assess socio-demographic data and self-evaluated physical as well as psychological condition and self-reliance of patients with MS (referred to the neurological testing according to the EDSS). Patients with RR-MS focus on fatalistic and hedonistic present more than healthy individuals. They also tend to reflect on their negative past experience. Acceptance of illness correlated positively with subjective assessment of physical and psychological condition as well as self-reliance, and negatively with objective disability score (measured with the use of EDSS) and a factor considering time of disease duration. Avoiding contemplation of negative past and concentrating on hedonistic future constitute significant predictors of illness acceptance. These results may be of importance in terms of holistic approach to treatment of RR-MS patients. In the initial stage of the disease progression, patients might benefit from psychological support due to change in temporal orientation.

  8. Model cortical association fields account for the time course and dependence on target complexity of human contour perception.

    Directory of Open Access Journals (Sweden)

    Vadas Gintautas

    2011-10-01

    Full Text Available Can lateral connectivity in the primary visual cortex account for the time dependence and intrinsic task difficulty of human contour detection? To answer this question, we created a synthetic image set that prevents sole reliance on either low-level visual features or high-level context for the detection of target objects. Rendered images consist of smoothly varying, globally aligned contour fragments (amoebas distributed among groups of randomly rotated fragments (clutter. The time course and accuracy of amoeba detection by humans was measured using a two-alternative forced choice protocol with self-reported confidence and variable image presentation time (20-200 ms, followed by an image mask optimized so as to interrupt visual processing. Measured psychometric functions were well fit by sigmoidal functions with exponential time constants of 30-91 ms, depending on amoeba complexity. Key aspects of the psychophysical experiments were accounted for by a computational network model, in which simulated responses across retinotopic arrays of orientation-selective elements were modulated by cortical association fields, represented as multiplicative kernels computed from the differences in pairwise edge statistics between target and distractor images. Comparing the experimental and the computational results suggests that each iteration of the lateral interactions takes at least [Formula: see text] ms of cortical processing time. Our results provide evidence that cortical association fields between orientation selective elements in early visual areas can account for important temporal and task-dependent aspects of the psychometric curves characterizing human contour perception, with the remaining discrepancies postulated to arise from the influence of higher cortical areas.

  9. Children's GPS-determined versus self-reported transport in leisure time and associations with parental perceptions of the neighborhood environment

    DEFF Research Database (Denmark)

    Vanwolleghem, Griet; Schipperijn, Jasper; Gheysen, Freja

    2016-01-01

    measured transport in leisure time and filled out a diary to assess self-reported transport in leisure time. Parents completed a questionnaire to assess parental perceptions of the neighborhood environment. Pearson correlations and t-tests were used to test for concurrent validity and differences between...... GPS-determined and self-reported transport in leisure time. Generalized linear models were used to determine the associations between the parental perceptions of the neighborhood environment and GPS-determined transport in leisure time. RESULTS: Overall, children under-reported their walking......BACKGROUND: This study aimed to examine both GPS-determined and self-reported walking, cycling and passive transport in leisure time during week- and weekend-days among 10 to 12-year old children. Comparisons between GPS-determined and self-reported transport in leisure time were investigated...

  10. Does the Timing of Transition Matter? Comparison of German Students' Self-Perceptions before and after Transition to Secondary School

    Science.gov (United States)

    Arens, A. Katrin; Yeung, Alexander Seeshing; Craven, Rhonda G.; Watermann, Rainer; Hasselhorn, Marcus

    2013-01-01

    The often observed decline in students' self-perceptions across transition to secondary school after grade 6 is often attributed to students' entry to puberty. This study aims to examine whether lowered self-perceptions can be observed after transition in Germany which occurs after grade 4 and thus takes place before puberty. Fifth graders (N =…

  11. Sensorimotor synchronization and perception of timing: effects of music training and task experience.

    Science.gov (United States)

    Repp, Bruno H

    2010-04-01

    To assess individual differences in basic synchronization skills and in perceptual sensitivity to timing deviations, brief tests made up of isochronous auditory sequences containing phase shifts or tempo changes were administered to 31 college students (most of them with little or no music training) and nine highly trained musicians (graduate students of music performance). Musicians showed smaller asynchronies, lower tapping variability, and greater perceptual sensitivity than college students, on average. They also showed faster phase correction following a tempo change in the pacing sequence. Unexpectedly, however, phase correction following a simple phase shift was unusually quick in both groups, especially in college students. It emerged that some of the musicians, who had previous experience with laboratory synchronization tasks, showed a much slower corrective response to phase shifts than did the other musicians. When these others were retested after having gained some task experience, their phase correction was slower than previously. These results show (1) that instantaneous phase correction in response to phase perturbations is more common than was previously believed, and suggest that (2) gradual phase correction is not a shortcoming but reflects a reduction in the strength of sensorimotor coupling afforded by practice.

  12. Psychological aspects of nuclear waste disposal: Long time perception and the question of discounting of risks

    International Nuclear Information System (INIS)

    Karlsson, G.; Svenson, O.

    1988-01-01

    Subjects of different ages and basic training indicated how they perceived risks related to spent nuclear fuel storage and located at different points of time into the future. The results indicated that minorities in all groups, ranging from about 10 to 40%, did not want to discount risks into the future. Those who discounted exhibited great inter and intra group variability. The physical discounting curves for e.g. both total radiation and for Pu-239 and -240 are within the range of curves generated by the groups for subjective discounting of risk. Politicians and experts were attributed equal shares of responsibility for risks of spent nuclear fuel in the future. About 10% to 40% of the subjects did not wish to discount responsibility. Discounting rates for those discounting varied so that some subjects decreased the level of responsibility to less than half 10 000 years into the future while others attributed this level of responsibility for 100 000 years and more. (orig./HP)

  13. A study on the validity of a computer-based game to assess cognitive processes, reward mechanisms, and time perception in children aged 4-8 years

    NARCIS (Netherlands)

    Peijnenborgh, J.C.A.W.; Hurks, P.M.; Aldenkamp, A.P.; van der Spek, E.D.; Rauterberg, G.W.M.; Vles, J.S.H.; Hendriksen, J.G.M.

    2016-01-01

    BACKGROUND: A computer-based game, named Timo's Adventure, was developed to assess specific cognitive functions (eg, attention, planning, and working memory), time perception, and reward mechanisms in young school-aged children. The game consists of 6 mini-games embedded in a story line and includes

  14. Extending the Simultaneous-Sequential Paradigm to Measure Perceptual Capacity for Features and Words

    Science.gov (United States)

    Scharff, Alec; Palmer, John; Moore, Cathleen M.

    2011-01-01

    In perception, divided attention refers to conditions in which multiple stimuli are relevant to an observer. To measure the effect of divided attention in terms of perceptual capacity, we introduce an extension of the simultaneous-sequential paradigm. The extension makes predictions for fixed-capacity models as well as for unlimited-capacity…

  15. Determinant factors of residential consumption and perception of energy conservation: Time-series analysis by large-scale questionnaire in Suita, Japan

    International Nuclear Information System (INIS)

    Hara, Keishiro; Uwasu, Michinori; Kishita, Yusuke; Takeda, Hiroyuki

    2015-01-01

    In this study, we examined determinant factors associated with the residential consumption and perception of savings of electricity and city gas; this was based on data collected from a large-scale questionnaire sent to households in Suita, Osaka Prefecture, Japan, in two different years: 2009 and 2013. We applied an ordered logit model to determine the overall trend of the determinant factors, and then we performed a more detailed analysis in order to understand the reasons why the determinant factors changed between the two periods. Results from the ordered logit model reveal that electricity and gas consumption was primarily determined by such factors as household income, number of family members, the number of home appliances, and the perceptions of energy savings; there was not much difference between the two years, although in 2013, household income did not affect the perception of energy savings. Detailed analysis demonstrated that households with high energy consumption and those with moderate consumption are becoming polarized and that there was a growing gap between consumption behavior and the perception of conservation. The implications derived from the analyses provide an essential insight into the design of a municipal policy to induce lifestyle changes for an energy-saving society. - Highlights: • Questionnaire was conducted to households in two years for time-series analysis. • We analyzed residential energy consumption and perception of savings in households. • Determinant factors for consumption and perception of savings were identified. • Households being wasteful of energy are also found willing to cut consumption. • Policy intervention could affect consumption pattern and perception of savings.

  16. Time-resolved influences of functional DAT1 and COMT variants on visual perception and post-processing.

    Directory of Open Access Journals (Sweden)

    Stephan Bender

    Full Text Available BACKGROUND: Dopamine plays an important role in orienting and the regulation of selective attention to relevant stimulus characteristics. Thus, we examined the influences of functional variants related to dopamine inactivation in the dopamine transporter (DAT1 and catechol-O-methyltransferase genes (COMT on the time-course of visual processing in a contingent negative variation (CNV task. METHODS: 64-channel EEG recordings were obtained from 195 healthy adolescents of a community-based sample during a continuous performance task (A-X version. Early and late CNV as well as preceding visual evoked potential components were assessed. RESULTS: Significant additive main effects of DAT1 and COMT on the occipito-temporal early CNV were observed. In addition, there was a trend towards an interaction between the two polymorphisms. Source analysis showed early CNV generators in the ventral visual stream and in frontal regions. There was a strong negative correlation between occipito-temporal visual post-processing and the frontal early CNV component. The early CNV time interval 500-1000 ms after the visual cue was specifically affected while the preceding visual perception stages were not influenced. CONCLUSIONS: Late visual potentials allow the genomic imaging of dopamine inactivation effects on visual post-processing. The same specific time-interval has been found to be affected by DAT1 and COMT during motor post-processing but not motor preparation. We propose the hypothesis that similar dopaminergic mechanisms modulate working memory encoding in both the visual and motor and perhaps other systems.

  17. Can patients with asthma feel inhaler therapy working right away? Two clinical trials testing the effect of timing of assessment on patient perception.

    Science.gov (United States)

    Leidy, Nancy Kline; Gutierrez, Benjamin; Lampl, Kathy; Uryniak, Tom; O'Brien, Christopher D

    2009-12-01

    Feeling a maintenance therapy work right away may provide positive reinforcement and may offer one way to improve adherence in patients with asthma. Precise measurement is required to accurately compare the presence of this effect across clinical trial treatment groups. Two randomized, controlled studies tested whether timing of assessment (daily vs weekly, study 1; and predose vs postdose, study 2) influenced patients' reports of whether they can feel a medication working right away (perception), and their satisfaction with this perception (satisfaction). These 2-week US-based multicenter double-blind, parallel-group studies included patients > or = 18 years of age with mild to moderate persistent asthma. In each, patients were randomized to one of two drugs with different onset profiles: budesonide/formoterol pressurized metered-dose inhaler (pMDI) 80/4.5 microg x 2 inhalations (160/9 microg) twice daily or budesonide pMDI 80 microg x 2 inhalations (160 microg) twice daily. Patients were further randomized to complete previously validated perception and satisfaction questions in a cross-over fashion, either daily and weekly (N = 123) or predose and postdose (N = 134). Patient surveys also assessed perceptions of the onset of effect of medication and their value of these perceptions. No significant differences were observed in patients' reports of perception, either daily versus weekly or predose versus postdose. A statistically significant difference in satisfaction was found in study 1 only, favoring weekly recall (p away (136 of 157 patients) identified positive airway sensations. Most patients reported that feeling their medication work right away is reassuring and would help them manage their asthma. Assessment timing has no effect on patient response to the perception of feeling a medication working right away. Differences found in satisfaction levels reported with weekly versus daily recall were consistent across treatment groups, indicating that no bias

  18. Comparison of Sequential and Variational Data Assimilation

    Science.gov (United States)

    Alvarado Montero, Rodolfo; Schwanenberg, Dirk; Weerts, Albrecht

    2017-04-01

    Data assimilation is a valuable tool to improve model state estimates by combining measured observations with model simulations. It has recently gained significant attention due to its potential in using remote sensing products to improve operational hydrological forecasts and for reanalysis purposes. This has been supported by the application of sequential techniques such as the Ensemble Kalman Filter which require no additional features within the modeling process, i.e. it can use arbitrary black-box models. Alternatively, variational techniques rely on optimization algorithms to minimize a pre-defined objective function. This function describes the trade-off between the amount of noise introduced into the system and the mismatch between simulated and observed variables. While sequential techniques have been commonly applied to hydrological processes, variational techniques are seldom used. In our believe, this is mainly attributed to the required computation of first order sensitivities by algorithmic differentiation techniques and related model enhancements, but also to lack of comparison between both techniques. We contribute to filling this gap and present the results from the assimilation of streamflow data in two basins located in Germany and Canada. The assimilation introduces noise to precipitation and temperature to produce better initial estimates of an HBV model. The results are computed for a hindcast period and assessed using lead time performance metrics. The study concludes with a discussion of the main features of each technique and their advantages/disadvantages in hydrological applications.

  19. Further explorations of the facing bias in biological motion perception: perspective cues, observer sex, and response times.

    Directory of Open Access Journals (Sweden)

    Ben Schouten

    Full Text Available The human visual system has evolved to be highly sensitive to visual information about other persons and their movements as is illustrated by the effortless perception of point-light figures or 'biological motion'. When presented orthographically, a point-light walker is interpreted in two anatomically plausible ways: As 'facing the viewer' or as 'facing away' from the viewer. However, human observers show a 'facing bias': They perceive such a point-light walker as facing towards them in about 70-80% of the cases. In studies exploring the role of social and biological relevance as a possible account for the facing bias, we found a 'figure gender effect': Male point-light figures elicit a stronger facing bias than female point-light figures. Moreover, we also found an 'observer gender effect': The 'figure gender effect' was stronger for male than for female observers. In the present study we presented to 11 males and 11 females point-light walkers of which, very subtly, the perspective information was manipulated by modifying the earlier reported 'perspective technique'. Proportions of 'facing the viewer' responses and reaction times were recorded. Results show that human observers, even in the absence of local shape or size cues, easily pick up on perspective cues, confirming recent demonstrations of high visual sensitivity to cues on whether another person is potentially approaching. We also found a consistent difference in how male and female observers respond to stimulus variations (figure gender or perspective cues that cause variations in the perceived in-depth orientation of a point-light walker. Thus, the 'figure gender effect' is possibly caused by changes in the relative locations and motions of the dots that the perceptual system tends to interpret as perspective cues. Third, reaction time measures confirmed the existence of the facing bias and recent research showing faster detection of approaching than receding biological motion.

  20. The pursuit of balance in sequential randomized trials

    Directory of Open Access Journals (Sweden)

    Raymond P. Guiteras

    2016-06-01

    Full Text Available In many randomized trials, subjects enter the sample sequentially. Because the covariates for all units are not known in advance, standard methods of stratification do not apply. We describe and assess the method of DA-optimal sequential allocation (Atkinson, 1982 for balancing stratification covariates across treatment arms. We provide simulation evidence that the method can provide substantial improvements in precision over commonly employed alternatives. We also describe our experience implementing the method in a field trial of a clean water and handwashing intervention in Dhaka, Bangladesh, the first time the method has been used. We provide advice and software for future researchers.

  1. Computing Sequential Equilibria for Two-Player Games

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2006-01-01

    Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Koller and Pfeffer pointed out that the strategies...... obtained by the algorithm are not necessarily sequentially rational and that this deficiency is often problematic for the practical applications. We show how to remove this deficiency by modifying the linear programs constructed by Koller, Megiddo and von Stengel so that pairs of strategies forming...... a sequential equilibrium are computed. In particular, we show that a sequential equilibrium for a two-player zero-sum game with imperfect information but perfect recall can be found in polynomial time. In addition, the equilibrium we find is normal-form perfect. Our technique generalizes to general-sum games...

  2. A Bayesian sequential processor approach to spectroscopic portal system decisions

    Energy Technology Data Exchange (ETDEWEB)

    Sale, K; Candy, J; Breitfeller, E; Guidry, B; Manatt, D; Gosnell, T; Chambers, D

    2007-07-31

    The development of faster more reliable techniques to detect radioactive contraband in a portal type scenario is an extremely important problem especially in this era of constant terrorist threats. Towards this goal the development of a model-based, Bayesian sequential data processor for the detection problem is discussed. In the sequential processor each datum (detector energy deposit and pulse arrival time) is used to update the posterior probability distribution over the space of model parameters. The nature of the sequential processor approach is that a detection is produced as soon as it is statistically justified by the data rather than waiting for a fixed counting interval before any analysis is performed. In this paper the Bayesian model-based approach, physics and signal processing models and decision functions are discussed along with the first results of our research.

  3. Exploring the sequential lineup advantage using WITNESS.

    Science.gov (United States)

    Goodsell, Charles A; Gronlund, Scott D; Carlson, Curt A

    2010-12-01

    Advocates claim that the sequential lineup is an improvement over simultaneous lineup procedures, but no formal (quantitatively specified) explanation exists for why it is better. The computational model WITNESS (Clark, Appl Cogn Psychol 17:629-654, 2003) was used to develop theoretical explanations for the sequential lineup advantage. In its current form, WITNESS produced a sequential advantage only by pairing conservative sequential choosing with liberal simultaneous choosing. However, this combination failed to approximate four extant experiments that exhibited large sequential advantages. Two of these experiments became the focus of our efforts because the data were uncontaminated by likely suspect position effects. Decision-based and memory-based modifications to WITNESS approximated the data and produced a sequential advantage. The next step is to evaluate the proposed explanations and modify public policy recommendations accordingly.

  4. Sequential lineup presentation: Patterns and policy

    OpenAIRE

    Lindsay, R C L; Mansour, Jamal K; Beaudry, J L; Leach, A-M; Bertrand, M I

    2009-01-01

    Sequential lineups were offered as an alternative to the traditional simultaneous lineup. Sequential lineups reduce incorrect lineup selections; however, the accompanying loss of correct identifications has resulted in controversy regarding adoption of the technique. We discuss the procedure and research relevant to (1) the pattern of results found using sequential versus simultaneous lineups; (2) reasons (theory) for differences in witness responses; (3) two methodological issues; and (4) im...

  5. The Bacterial Sequential Markov Coalescent.

    Science.gov (United States)

    De Maio, Nicola; Wilson, Daniel J

    2017-05-01

    Bacteria can exchange and acquire new genetic material from other organisms directly and via the environment. This process, known as bacterial recombination, has a strong impact on the evolution of bacteria, for example, leading to the spread of antibiotic resistance across clades and species, and to the avoidance of clonal interference. Recombination hinders phylogenetic and transmission inference because it creates patterns of substitutions (homoplasies) inconsistent with the hypothesis of a single evolutionary tree. Bacterial recombination is typically modeled as statistically akin to gene conversion in eukaryotes, i.e. , using the coalescent with gene conversion (CGC). However, this model can be very computationally demanding as it needs to account for the correlations of evolutionary histories of even distant loci. So, with the increasing popularity of whole genome sequencing, the need has emerged for a faster approach to model and simulate bacterial genome evolution. We present a new model that approximates the coalescent with gene conversion: the bacterial sequential Markov coalescent (BSMC). Our approach is based on a similar idea to the sequential Markov coalescent (SMC)-an approximation of the coalescent with crossover recombination. However, bacterial recombination poses hurdles to a sequential Markov approximation, as it leads to strong correlations and linkage disequilibrium across very distant sites in the genome. Our BSMC overcomes these difficulties, and shows a considerable reduction in computational demand compared to the exact CGC, and very similar patterns in simulated data. We implemented our BSMC model within new simulation software FastSimBac. In addition to the decreased computational demand compared to previous bacterial genome evolution simulators, FastSimBac provides more general options for evolutionary scenarios, allowing population structure with migration, speciation, population size changes, and recombination hotspots. FastSimBac is

  6. Biased lineups: sequential presentation reduces the problem.

    Science.gov (United States)

    Lindsay, R C; Lea, J A; Nosworthy, G J; Fulford, J A; Hector, J; LeVan, V; Seabrook, C

    1991-12-01

    Biased lineups have been shown to increase significantly false, but not correct, identification rates (Lindsay, Wallbridge, & Drennan, 1987; Lindsay & Wells, 1980; Malpass & Devine, 1981). Lindsay and Wells (1985) found that sequential lineup presentation reduced false identification rates, presumably by reducing reliance on relative judgment processes. Five staged-crime experiments were conducted to examine the effect of lineup biases and sequential presentation on eyewitness recognition accuracy. Sequential lineup presentation significantly reduced false identification rates from fair lineups as well as from lineups biased with regard to foil similarity, instructions, or witness attire, and from lineups biased in all of these ways. The results support recommendations that police present lineups sequentially.

  7. Clinical evaluation of synthetic aperture sequential beamforming

    DEFF Research Database (Denmark)

    Hansen, Peter Møller; Hemmsen, Martin Christian; Lange, Theis

    2012-01-01

    In this study clinically relevant ultrasound images generated with synthetic aperture sequential beamforming (SASB) is compared to images generated with a conventional technique. The advantage of SASB is the ability to produce high resolution ultrasound images with a high frame rate and at the same...... time massively reduce the amount of generated data. SASB was implemented in a system consisting of a conventional ultrasound scanner connected to a PC via a research interface. This setup enables simultaneous recording with both SASB and conventional technique. Eighteen volunteers were ultrasound...... scanned abdominally, and 84 sequence pairs were recorded. Each sequence pair consists of two simultaneous recordings of the same anatomical location with SASB and conventional B-mode imaging. The images were evaluated in terms of spatial resolution, contrast, unwanted artifacts, and penetration depth...

  8. Gleason-Busch theorem for sequential measurements

    Science.gov (United States)

    Flatt, Kieran; Barnett, Stephen M.; Croke, Sarah

    2017-12-01

    Gleason's theorem is a statement that, given some reasonable assumptions, the Born rule used to calculate probabilities in quantum mechanics is essentially unique [A. M. Gleason, Indiana Univ. Math. J. 6, 885 (1957), 10.1512/iumj.1957.6.56050]. We show that Gleason's theorem contains within it also the structure of sequential measurements, and along with this the state update rule. We give a small set of axioms, which are physically motivated and analogous to those in Busch's proof of Gleason's theorem [P. Busch, Phys. Rev. Lett. 91, 120403 (2003), 10.1103/PhysRevLett.91.120403], from which the familiar Kraus operator form follows. An axiomatic approach has practical relevance as well as fundamental interest, in making clear those assumptions which underlie the security of quantum communication protocols. Interestingly, the two-time formalism is seen to arise naturally in this approach.

  9. Sequential search leads to faster, more efficient fragment-based de novo protein structure prediction.

    Science.gov (United States)

    de Oliveira, Saulo H P; Law, Eleanor C; Shi, Jiye; Deane, Charlotte M

    2018-04-01

    Most current de novo structure prediction methods randomly sample protein conformations and thus require large amounts of computational resource. Here, we consider a sequential sampling strategy, building on ideas from recent experimental work which shows that many proteins fold cotranslationally. We have investigated whether a pseudo-greedy search approach, which begins sequentially from one of the termini, can improve the performance and accuracy of de novo protein structure prediction. We observed that our sequential approach converges when fewer than 20 000 decoys have been produced, fewer than commonly expected. Using our software, SAINT2, we also compared the run time and quality of models produced in a sequential fashion against a standard, non-sequential approach. Sequential prediction produces an individual decoy 1.5-2.5 times faster than non-sequential prediction. When considering the quality of the best model, sequential prediction led to a better model being produced for 31 out of 41 soluble protein validation cases and for 18 out of 24 transmembrane protein cases. Correct models (TM-Score > 0.5) were produced for 29 of these cases by the sequential mode and for only 22 by the non-sequential mode. Our comparison reveals that a sequential search strategy can be used to drastically reduce computational time of de novo protein structure prediction and improve accuracy. Data are available for download from: http://opig.stats.ox.ac.uk/resources. SAINT2 is available for download from: https://github.com/sauloho/SAINT2. saulo.deoliveira@dtc.ox.ac.uk. Supplementary data are available at Bioinformatics online.

  10. Immediate Sequential Bilateral Cataract Surgery

    DEFF Research Database (Denmark)

    Kessel, Line; Andresen, Jens; Erngaard, Ditte

    2015-01-01

    The aim of the present systematic review was to examine the benefits and harms associated with immediate sequential bilateral cataract surgery (ISBCS) with specific emphasis on the rate of complications, postoperative anisometropia, and subjective visual function in order to formulate evidence......-based national Danish guidelines for cataract surgery. A systematic literature review in PubMed, Embase, and Cochrane central databases identified three randomized controlled trials that compared outcome in patients randomized to ISBCS or bilateral cataract surgery on two different dates. Meta-analyses were...... performed using the Cochrane Review Manager software. The quality of the evidence was assessed using the GRADE method (Grading of Recommendation, Assessment, Development, and Evaluation). We did not find any difference in the risk of complications or visual outcome in patients randomized to ISBCS or surgery...

  11. Random and cooperative sequential adsorption

    Science.gov (United States)

    Evans, J. W.

    1993-10-01

    Irreversible random sequential adsorption (RSA) on lattices, and continuum "car parking" analogues, have long received attention as models for reactions on polymer chains, chemisorption on single-crystal surfaces, adsorption in colloidal systems, and solid state transformations. Cooperative generalizations of these models (CSA) are sometimes more appropriate, and can exhibit richer kinetics and spatial structure, e.g., autocatalysis and clustering. The distribution of filled or transformed sites in RSA and CSA is not described by an equilibrium Gibbs measure. This is the case even for the saturation "jammed" state of models where the lattice or space cannot fill completely. However exact analysis is often possible in one dimension, and a variety of powerful analytic methods have been developed for higher dimensional models. Here we review the detailed understanding of asymptotic kinetics, spatial correlations, percolative structure, etc., which is emerging for these far-from-equilibrium processes.

  12. The sequential trauma score - a new instrument for the sequential mortality prediction in major trauma*

    Directory of Open Access Journals (Sweden)

    Huber-Wagner S

    2010-05-01

    Full Text Available Abstract Background There are several well established scores for the assessment of the prognosis of major trauma patients that all have in common that they can be calculated at the earliest during intensive care unit stay. We intended to develop a sequential trauma score (STS that allows prognosis at several early stages based on the information that is available at a particular time. Study design In a retrospective, multicenter study using data derived from the Trauma Registry of the German Trauma Society (2002-2006, we identified the most relevant prognostic factors from the patients basic data (P, prehospital phase (A, early (B1, and late (B2 trauma room phase. Univariate and logistic regression models as well as score quality criteria and the explanatory power have been calculated. Results A total of 2,354 patients with complete data were identified. From the patients basic data (P, logistic regression showed that age was a significant predictor of survival (AUCmodel p, area under the curve = 0.63. Logistic regression of the prehospital data (A showed that blood pressure, pulse rate, Glasgow coma scale (GCS, and anisocoria were significant predictors (AUCmodel A = 0.76; AUCmodel P + A = 0.82. Logistic regression of the early trauma room phase (B1 showed that peripheral oxygen saturation, GCS, anisocoria, base excess, and thromboplastin time to be significant predictors of survival (AUCmodel B1 = 0.78; AUCmodel P +A + B1 = 0.85. Multivariate analysis of the late trauma room phase (B2 detected cardiac massage, abbreviated injury score (AIS of the head ≥ 3, the maximum AIS, the need for transfusion or massive blood transfusion, to be the most important predictors (AUCmodel B2 = 0.84; AUCfinal model P + A + B1 + B2 = 0.90. The explanatory power - a tool for the assessment of the relative impact of each segment to mortality - is 25% for P, 7% for A, 17% for B1 and 51% for B2. A spreadsheet for the easy calculation of the sequential trauma

  13. Sequential determination of important ecotoxic radionuclides in nuclear waste samples

    International Nuclear Information System (INIS)

    Bilohuscin, J.

    2016-01-01

    In the dissertation thesis we focused on the development and optimization of a sequential determination method for radionuclides 93 Zr, 94 Nb, 99 Tc and 126 Sn, employing extraction chromatography sorbents TEVA (R) Resin and Anion Exchange Resin, supplied by Eichrom Industries. Prior to the attestation of sequential separation of these proposed radionuclides from radioactive waste samples, a unique sequential procedure of 90 Sr, 239 Pu, 241 Am separation from urine matrices was tried, using molecular recognition sorbents of AnaLig (R) series and extraction chromatography sorbent DGA (R) Resin. On these experiments, four various sorbents were continually used for separation, including PreFilter Resin sorbent, which removes interfering organic materials present in raw urine. After the acquisition of positive results of this sequential procedure followed experiments with a 126 Sn separation using TEVA (R) Resin and Anion Exchange Resin sorbents. Radiochemical recoveries obtained from samples of radioactive evaporate concentrates and sludge showed high efficiency of the separation, while values of 126 Sn were under the minimum detectable activities MDA. Activity of 126 Sn was determined after ingrowth of daughter nuclide 126m Sb on HPGe gamma detector, with minimal contamination of gamma interfering radionuclides with decontamination factors (D f ) higher then 1400 for 60 Co and 47000 for 137 Cs. Based on the acquired experiments and results of these separation procedures, a complex method of sequential separation of 93 Zr, 94 Nb, 99 Tc and 126 Sn was proposed, which included optimization steps similar to those used in previous parts of the dissertation work. Application of the sequential separation method for sorbents TEVA (R) Resin and Anion Exchange Resin on real samples of radioactive wastes provided satisfactory results and an economical, time sparing, efficient method. (author)

  14. Leadership emergence over time in short-lived groups: Integrating expectations states theory with temporal person-perception and self-serving bias.

    Science.gov (United States)

    Kalish, Yuval; Luria, Gil

    2016-10-01

    Research into leadership emergence typically focuses on the attributes of the emergent leader. By considering also the attributes of perceivers and the passage of time, we develop a more complete theory of leadership emergence in short-lived groups. Using expectation states theory as an overarching theoretical framework, and integrating it with the surface- and deep-level diversity literature and with theories of self-serving biases, we examine the predictors of leadership emergence in short timeframes. We conduct a field study in a military assessment boot camp (a pilot study, n = 60; and a main study, n = 89). We use cross-sectional and longitudinal exponential random graph models to analyze data on participants' abilities and on their perceptions of who, in their respective groups, were "leaders." We find that the criteria by which people perceive leadership in others change over time, from easily noticeable attributes to covert leadership-relevant attributes, and that people also rely on leadership-relevant attributes that they possess at high levels to inform their perceptions of leadership in others. The integration of expectation states theory, attribute salience over time and theories of self-serving bias is needed for a full understanding of leadership emergence in groups, because perceivers' own abilities are instrumental in shaping their perceptions of emergent leadership over time. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Students as Non-Standard Employees. Exploring Work Related Issues in Students’ Perceptions on their Term-time Job

    DEFF Research Database (Denmark)

    Winkler, Ingo

    2008-01-01

    The article presents the results of an explorative study that aimed at exploring work related issues in students’ perceptions of their job as atypical employees. An individual picture of the experienced work reality of students is drawn according to work task, flexible working hours, instructions...... and training opportunities, students’ relations to other employees, and social integration. By adopting a qualitative design, I was able to emphasize the subjective perspective of students describing their very own experiences as flexible workers. The study revealed various perceptions of students working...... as flexible employees and related this picture to current empirical and theoretical research in the field of non-standard employment....

  16. A study on the validity of a computer-based game to assess cognitive processes, reward mechanisms, and time perception in children aged 4-8 years

    OpenAIRE

    Peijnenborgh, Janneke; Hurks, PM Petra; Aldenkamp, AP Albert; Spek, van der, ED Erik; Rauterberg, GWM Matthias; Vles, JSH Johan; Hendriksen, JGM

    2016-01-01

    Background A computer-based game, named Timo?s Adventure, was developed to assess specific cognitive functions (eg, attention, planning, and working memory), time perception, and reward mechanisms in young school-aged children. The game consists of 6 mini-games embedded in a story line and includes fantasy elements to enhance motivation. Objective The aim of this study was to investigate the validity of Timo?s Adventure in normally developing children and in children with attention-deficit/hy...

  17. Trial Sequential Methods for Meta-Analysis

    Science.gov (United States)

    Kulinskaya, Elena; Wood, John

    2014-01-01

    Statistical methods for sequential meta-analysis have applications also for the design of new trials. Existing methods are based on group sequential methods developed for single trials and start with the calculation of a required information size. This works satisfactorily within the framework of fixed effects meta-analysis, but conceptual…

  18. Is It Time for a Sudden Infant Death Syndrome (SIDS) Awareness Campaign? Community Stakeholders' Perceptions of SIDS

    Science.gov (United States)

    Gollenberg, Audra; Fendley, Kim

    2018-01-01

    Sudden infant death syndrome (SIDS) remains a leading cause of infant death in the United States, and in Virginia. We sought to gauge the perceptions among community-identified stakeholders regarding community resource needs to reduce SIDS. Snowball sampling identified important community stakeholders to be interviewed as key informants. A…

  19. Students as Non-Standard Employees. Exploring Work Related Issues in Students’ Perceptions on their Term-time Job

    DEFF Research Database (Denmark)

    Winkler, Ingo

    2008-01-01

    and training opportunities, students’ relations to other employees, and social integration. By adopting a qualitative design, I was able to emphasize the subjective perspective of students describing their very own experiences as flexible workers. The study revealed various perceptions of students working...... as flexible employees and related this picture to current empirical and theoretical research in the field of non-standard employment....

  20. Time will tell: changes in risk perception and the processing of risk information about the Y2K-risk.

    NARCIS (Netherlands)

    Kuttschreuter, M.; Gutteling, Jan M.

    2004-01-01

    A field study was performed on the perceived risks related to the Y2K-problem. Two cross-sectional surveys were executed to study whether risk perception regarding the Y2K-problem, the perceived societal and personal capabilities to mitigate the risks, the attitude toward computers and the attitude

  1. "You Must Know Where You Come From": South African Youths' Perceptions of Religion in Time of Social Change

    Science.gov (United States)

    Brittian, Aerika S.; Lewin, Nina; Norris, Shane A.

    2013-01-01

    This study examined South African youths' perceptions of religion during a period of social and economic transition. In-depth interviews were conducted with 55 Black South African youth (age 18) living in the Johannesburg-Soweto metropolitan area. Data were analyzed in a manner consistent with grounded theory methodology and structural coding.…

  2. Puberty and Physical Self-Perceptions of Competitive Female Figure Skaters II: Maturational Timing, Skating Context, and Ability Status

    Science.gov (United States)

    Monsma, Eva V.

    2008-01-01

    One study of figure skaters found that menarcheal status was a stronger predictor than age in explaining the variance in their self-perceptions. Postmenarcheal skaters had significantly lower self-esteem and physical self-concept and were less satisfied with their appearance than premenarcheal skaters. Surprisingly, skating context (i.e., skating…

  3. Academic Self-Handicapping: Relationships with Learning Specific and General Self-Perceptions and Academic Performance over Time

    Science.gov (United States)

    Gadbois, Shannon A.; Sturgeon, Ryan D.

    2011-01-01

    Background: Academic self-handicapping (ASH) tendencies, strategies students employ that increase their chances of failure on assessments while protecting self-esteem, are correlated with classroom goal structures and to learners' general self-perceptions and learning strategies. In particular, greater ASH is related to poorer academic performance…

  4. Treatment comfort, time perception, and preference for conventional and digital impression techniques : A comparative study in young patients

    NARCIS (Netherlands)

    Burhardt, Lukasz; Livas, Christos; Kerdijk, Wouter; van der Meer, Wicher Joerd; Ren, Yijin

    INTRODUCTION: The aim of this crossover study was to assess perceptions and preferences for impression techniques in young orthodontic patients receiving alginate and 2 different digital impressions. METHODS: Thirty-eight subjects aged 10 to 17 years requiring impressions for orthodontic treatment

  5. Research on parallel algorithm for sequential pattern mining

    Science.gov (United States)

    Zhou, Lijuan; Qin, Bai; Wang, Yu; Hao, Zhongxiao

    2008-03-01

    Sequential pattern mining is the mining of frequent sequences related to time or other orders from the sequence database. Its initial motivation is to discover the laws of customer purchasing in a time section by finding the frequent sequences. In recent years, sequential pattern mining has become an important direction of data mining, and its application field has not been confined to the business database and has extended to new data sources such as Web and advanced science fields such as DNA analysis. The data of sequential pattern mining has characteristics as follows: mass data amount and distributed storage. Most existing sequential pattern mining algorithms haven't considered the above-mentioned characteristics synthetically. According to the traits mentioned above and combining the parallel theory, this paper puts forward a new distributed parallel algorithm SPP(Sequential Pattern Parallel). The algorithm abides by the principal of pattern reduction and utilizes the divide-and-conquer strategy for parallelization. The first parallel task is to construct frequent item sets applying frequent concept and search space partition theory and the second task is to structure frequent sequences using the depth-first search method at each processor. The algorithm only needs to access the database twice and doesn't generate the candidated sequences, which abates the access time and improves the mining efficiency. Based on the random data generation procedure and different information structure designed, this paper simulated the SPP algorithm in a concrete parallel environment and implemented the AprioriAll algorithm. The experiments demonstrate that compared with AprioriAll, the SPP algorithm had excellent speedup factor and efficiency.

  6. Sequential lineup laps and eyewitness accuracy.

    Science.gov (United States)

    Steblay, Nancy K; Dietrich, Hannah L; Ryan, Shannon L; Raczynski, Jeanette L; James, Kali A

    2011-08-01

    Police practice of double-blind sequential lineups prompts a question about the efficacy of repeated viewings (laps) of the sequential lineup. Two laboratory experiments confirmed the presence of a sequential lap effect: an increase in witness lineup picks from first to second lap, when the culprit was a stranger. The second lap produced more errors than correct identifications. In Experiment 2, lineup diagnosticity was significantly higher for sequential lineup procedures that employed a single versus double laps. Witnesses who elected to view a second lap made significantly more errors than witnesses who chose to stop after one lap or those who were required to view two laps. Witnesses with prior exposure to the culprit did not exhibit a sequential lap effect.

  7. Sequential Product of Quantum Effects: An Overview

    Science.gov (United States)

    Gudder, Stan

    2010-12-01

    This article presents an overview for the theory of sequential products of quantum effects. We first summarize some of the highlights of this relatively recent field of investigation and then provide some new results. We begin by discussing sequential effect algebras which are effect algebras endowed with a sequential product satisfying certain basic conditions. We then consider sequential products of (discrete) quantum measurements. We next treat transition effect matrices (TEMs) and their associated sequential product. A TEM is a matrix whose entries are effects and whose rows form quantum measurements. We show that TEMs can be employed for the study of quantum Markov chains. Finally, we prove some new results concerning TEMs and vector densities.

  8. Building a Lego wall: Sequential action selection.

    Science.gov (United States)

    Arnold, Amy; Wing, Alan M; Rotshtein, Pia

    2017-05-01

    The present study draws together two distinct lines of enquiry into the selection and control of sequential action: motor sequence production and action selection in everyday tasks. Participants were asked to build 2 different Lego walls. The walls were designed to have hierarchical structures with shared and dissociated colors and spatial components. Participants built 1 wall at a time, under low and high load cognitive states. Selection times for correctly completed trials were measured using 3-dimensional motion tracking. The paradigm enabled precise measurement of the timing of actions, while using real objects to create an end product. The experiment demonstrated that action selection was slowed at decision boundary points, relative to boundaries where no between-wall decision was required. Decision points also affected selection time prior to the actual selection window. Dual-task conditions increased selection errors. Errors mostly occurred at boundaries between chunks and especially when these required decisions. The data support hierarchical control of sequenced behavior. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  9. Moments in time

    Directory of Open Access Journals (Sweden)

    Marc eWittmann

    2011-10-01

    Full Text Available It has been suggested that perception and action can be understood as evolving in temporal epochs or sequential processing units. Successive events are fused into units forming a unitary experience or ‘psychological present’. Studies have identified several temporal integration levels on different time scales which are fundamental for our understanding of behaviour and subjective experience. In recent literature concerning the philosophy and neuroscience of consciousness these separate temporal processing levels are not always precisely distinguished. Therefore, empirical evidence from psychophysics and neuropsychology on these distinct temporal processing levels is presented and discussed within philosophical conceptualizations of time experience. On an elementary level, one can identify a functional moment, a basic temporal building block of perception in the range of milliseconds that defines simultaneity and succession. Below a certain threshold temporal order is not perceived, individual events are processed as co-temporal. On a second level, an experienced moment, which is based on temporal integration of up to a few seconds, has been reported in many qualitatively different experiments in perception and action. It has been suggested that this segmental processing mechanism creates temporal windows that provide a logistical basis for conscious representation and the experience of nowness. On a third level of integration, continuity of experience is enabled by working-memory in the range of multiple seconds allowing the maintenance of cognitive operations and emotional feelings, leading to mental presence, a temporal window of an individual’s experienced presence.

  10. Multilevel sequential Monte Carlo samplers

    KAUST Repository

    Beskos, Alexandros; Jasra, Ajay; Law, Kody; Tempone, Raul; Zhou, Yan

    2016-01-01

    In this article we consider the approximation of expectations w.r.t. probability distributions associated to the solution of partial differential equations (PDEs); this scenario appears routinely in Bayesian inverse problems. In practice, one often has to solve the associated PDE numerically, using, for instance finite element methods which depend on the step-size level . hL. In addition, the expectation cannot be computed analytically and one often resorts to Monte Carlo methods. In the context of this problem, it is known that the introduction of the multilevel Monte Carlo (MLMC) method can reduce the amount of computational effort to estimate expectations, for a given level of error. This is achieved via a telescoping identity associated to a Monte Carlo approximation of a sequence of probability distributions with discretization levels . ∞>h0>h1⋯>hL. In many practical problems of interest, one cannot achieve an i.i.d. sampling of the associated sequence and a sequential Monte Carlo (SMC) version of the MLMC method is introduced to deal with this problem. It is shown that under appropriate assumptions, the attractive property of a reduction of the amount of computational effort to estimate expectations, for a given level of error, can be maintained within the SMC context. That is, relative to exact sampling and Monte Carlo for the distribution at the finest level . hL. The approach is numerically illustrated on a Bayesian inverse problem. © 2016 Elsevier B.V.

  11. Multilevel sequential Monte Carlo samplers

    KAUST Repository

    Beskos, Alexandros

    2016-08-29

    In this article we consider the approximation of expectations w.r.t. probability distributions associated to the solution of partial differential equations (PDEs); this scenario appears routinely in Bayesian inverse problems. In practice, one often has to solve the associated PDE numerically, using, for instance finite element methods which depend on the step-size level . hL. In addition, the expectation cannot be computed analytically and one often resorts to Monte Carlo methods. In the context of this problem, it is known that the introduction of the multilevel Monte Carlo (MLMC) method can reduce the amount of computational effort to estimate expectations, for a given level of error. This is achieved via a telescoping identity associated to a Monte Carlo approximation of a sequence of probability distributions with discretization levels . ∞>h0>h1⋯>hL. In many practical problems of interest, one cannot achieve an i.i.d. sampling of the associated sequence and a sequential Monte Carlo (SMC) version of the MLMC method is introduced to deal with this problem. It is shown that under appropriate assumptions, the attractive property of a reduction of the amount of computational effort to estimate expectations, for a given level of error, can be maintained within the SMC context. That is, relative to exact sampling and Monte Carlo for the distribution at the finest level . hL. The approach is numerically illustrated on a Bayesian inverse problem. © 2016 Elsevier B.V.

  12. Sequential provisional implant prosthodontics therapy.

    Science.gov (United States)

    Zinner, Ira D; Markovits, Stanley; Jansen, Curtis E; Reid, Patrick E; Schnader, Yale E; Shapiro, Herbert J

    2012-01-01

    The fabrication and long-term use of first- and second-stage provisional implant prostheses is critical to create a favorable prognosis for function and esthetics of a fixed-implant supported prosthesis. The fixed metal and acrylic resin cemented first-stage prosthesis, as reviewed in Part I, is needed for prevention of adjacent and opposing tooth movement, pressure on the implant site as well as protection to avoid micromovement of the freshly placed implant body. The second-stage prosthesis, reviewed in Part II, should be used following implant uncovering and abutment installation. The patient wears this provisional prosthesis until maturation of the bone and healing of soft tissues. The second-stage provisional prosthesis is also a fail-safe mechanism for possible early implant failures and also can be used with late failures and/or for the necessity to repair the definitive prosthesis. In addition, the screw-retained provisional prosthesis is used if and when an implant requires removal or other implants are to be placed as in a sequential approach. The creation and use of both first- and second-stage provisional prostheses involve a restorative dentist, dental technician, surgeon, and patient to work as a team. If the dentist alone cannot do diagnosis and treatment planning, surgery, and laboratory techniques, he or she needs help by employing the expertise of a surgeon and a laboratory technician. This team approach is essential for optimum results.

  13. A Perceptual Pathway to Bias: Interracial Exposure Reduces Abrupt Shifts in Real-Time Race Perception That Predict Mixed-Race Bias.

    Science.gov (United States)

    Freeman, Jonathan B; Pauker, Kristin; Sanchez, Diana T

    2016-04-01

    In two national samples, we examined the influence of interracial exposure in one's local environment on the dynamic process underlying race perception and its evaluative consequences. Using a mouse-tracking paradigm, we found in Study 1 that White individuals with low interracial exposure exhibited a unique effect of abrupt, unstable White-Black category shifting during real-time perception of mixed-race faces, consistent with predictions from a neural-dynamic model of social categorization and computational simulations. In Study 2, this shifting effect was replicated and shown to predict a trust bias against mixed-race individuals and to mediate the effect of low interracial exposure on that trust bias. Taken together, the findings demonstrate that interracial exposure shapes the dynamics through which racial categories activate and resolve during real-time perceptions, and these initial perceptual dynamics, in turn, may help drive evaluative biases against mixed-race individuals. Thus, lower-level perceptual aspects of encounters with racial ambiguity may serve as a foundation for mixed-race prejudice. © The Author(s) 2016.

  14. A path-level exact parallelization strategy for sequential simulation

    Science.gov (United States)

    Peredo, Oscar F.; Baeza, Daniel; Ortiz, Julián M.; Herrero, José R.

    2018-01-01

    Sequential Simulation is a well known method in geostatistical modelling. Following the Bayesian approach for simulation of conditionally dependent random events, Sequential Indicator Simulation (SIS) method draws simulated values for K categories (categorical case) or classes defined by K different thresholds (continuous case). Similarly, Sequential Gaussian Simulation (SGS) method draws simulated values from a multivariate Gaussian field. In this work, a path-level approach to parallelize SIS and SGS methods is presented. A first stage of re-arrangement of the simulation path is performed, followed by a second stage of parallel simulation for non-conflicting nodes. A key advantage of the proposed parallelization method is to generate identical realizations as with the original non-parallelized methods. Case studies are presented using two sequential simulation codes from GSLIB: SISIM and SGSIM. Execution time and speedup results are shown for large-scale domains, with many categories and maximum kriging neighbours in each case, achieving high speedup results in the best scenarios using 16 threads of execution in a single machine.

  15. Standardized method for reproducing the sequential X-rays flap

    International Nuclear Information System (INIS)

    Brenes, Alejandra; Molina, Katherine; Gudino, Sylvia

    2009-01-01

    A method is validated to estandardize in the taking, developing and analysis of bite-wing radiographs taken in sequential way, in order to compare and evaluate detectable changes in the evolution of the interproximal lesions through time. A radiographic positioner called XCP® is modified by means of a rigid acrylic guide, to achieve proper of the X ray equipment core positioning relative to the XCP® ring and the reorientation during the sequential x-rays process. 16 subjects of 4 to 40 years old are studied for a total number of 32 registries. Two x-rays of the same block of teeth of each subject have been taken in sequential way, with a minimal difference of 30 minutes between each one, before the placement of radiographic attachment. The images have been digitized with a Super Cam® scanner and imported to a software. The measurements in X and Y-axis for both x-rays were performed to proceed to compare. The intraclass correlation index (ICI) has shown that the proposed method is statistically related to measurement (mm) obtained in the X and Y-axis for both sequential series of x-rays (p=0.01). The measures of central tendency and dispersion have shown that the usual occurrence is indifferent between the two measurements (Mode 0.000 and S = 0083 and 0.109) and that the probability of occurrence of different values is lower than expected. (author) [es

  16. Exploring the effects of driving experience on hazard awareness and risk perception via real-time hazard identification, hazard classification, and rating tasks.

    Science.gov (United States)

    Borowsky, Avinoam; Oron-Gilad, Tal

    2013-10-01

    This study investigated the effects of driving experience on hazard awareness and risk perception skills. These topics have previously been investigated separately, yet a novel approach is suggested where hazard awareness and risk perception are examined concurrently. Young, newly qualified drivers, experienced drivers, and a group of commercial drivers, namely, taxi drivers performed three consecutive tasks: (1) observed 10 short movies of real-world driving situations and were asked to press a button each time they identified a hazardous situation; (2) observed one of three possible sub-sets of 8 movies (out of the 10 they have seen earlier) for the second time, and were asked to categorize them into an arbitrary number of clusters according to the similarity in their hazardous situation; and (3) observed the same sub-set for a third time and following each movie were asked to rate its level of hazardousness. The first task is considered a real-time identification task while the other two are performed using hindsight. During it participants' eye movements were recorded. Results showed that taxi drivers were more sensitive to hidden hazards than the other driver groups and that young-novices were the least sensitive. Young-novice drivers also relied heavily on materialized hazards in their categorization structure. In addition, it emerged that risk perception was derived from two major components: the likelihood of a crash and the severity of its outcome. Yet, the outcome was rarely considered under time pressure (i.e., in real-time hazard identification tasks). Using hindsight, when drivers were provided with the opportunity to rate the movies' hazardousness more freely (rating task) they considered both components. Otherwise, in the categorization task, they usually chose the severity of the crash outcome as their dominant criterion. Theoretical and practical implications are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. POLYP: an automatic device for drawing sequential samples of gas

    Energy Technology Data Exchange (ETDEWEB)

    Gaglione, P; Koechler, C; Stanchi, L

    1974-12-01

    Polyp is an automatic device consisting of electronic equipment which drives sequentially 8 small pumps for drawing samples of gas. The electronic circuit is driven by a quartz oscillator and allows for the preselection of a waiting time in such a manner that a set of similar instruments placed in suitable position in the open country will start simultaneously. At the same time the first pump of each instrument will inflate a plastic bag for a preset time. The other seven pumps will inflate sequentially the other bags. The instrument is powered by rechargeable batteries and realized with C-MUS integrated circuits for a nearly negligible consumption. As it is foreseen for field operation it is waterproof.

  18. POLYP: an automatic device for drawing sequential samples of gas

    International Nuclear Information System (INIS)

    Gaglione, P.; Koechler, C.; Stanchi, L.

    1974-12-01

    POLYP is an automatic device consisting of an electronic equipment which drives sequentially 8 small pumps for drawing samples of gas. The electronic circuit is driven by a quartz oscillator and allows for the preselection of a waiting time in such a manner that a set of similar instruments placed in suitable position in the open country will start simultaneously. At the same time the first pump of each instrument will inflate a plastic bag for a preset time. Thereafter the other seven pumps will inflate sequentially the other bag. The instrument is powered by rechargeable batteries and realized with C-MOS integrated circuits for a nearly negligible consumption. As it is foreseen for field operation it is waterproof

  19. Commentary on "The Perception and Cognition of Time in Balinese Music" by Andrew Clay McGraw

    OpenAIRE

    Ian Cross; Satinder Gill; Sarah Knight; Chris Nash; Tal-Chen Rabinowitch; Lydia Slobodian; Neta Spiro; Ghofur Woodruff; Matthew Woolhouse

    2008-01-01

    We review the paper by Andrew Clay McGraw, noting that it represents an interesting and valuable contribution to the study of music in cognition in its informed exploration of non-western musical perceptions. We raise a number of concerns about the methods used, and make suggestions as to how the issues that were empirically addressed in the paper might have been tackled in ways that would have enhanced the interpretability of its findings.

  20. Patients' perception of DED and its relation with time to diagnosis and quality of life: an international and multilingual survey.

    Science.gov (United States)

    Labetoulle, Marc; Rolando, Maurizio; Baudouin, Christophe; van Setten, Gysbert

    2017-08-01

    To improve understanding of patients' experience and perception of dry eye disease (DED) and its impact on quality of life (QoL). This survey was observational, non-interventional and cross-sectional. The survey was conducted online on 706 patients with DED from five European countries (France, Germany, Italy, Spain and the UK). All patients met the following inclusion criteria: 40 years or older with DED diagnosed by a healthcare professional (HCP), not wearing contact lenses and using tear substitutes daily for at least 6 months. The survey (performed in the five native languages) included 9 screening questions (inclusion criteria) and 26 complementary questions about patients' demography, disease history, DED diagnosis, use of relief treatments, perceptions of DED condition and its impact on QoL. Overall, 218 of 706 (31%) patients perceived DED as a 'disease' or even a 'handicap', and 468 of 706 (66%) as a 'discomfort'. High impact of DED on patients' QoL was associated with negative perception, delay in diagnosis, visits to more than one HCP before diagnosis and high frequency of treatment use. This survey also provided us with a list of language-specific keywords that patients used most frequently to spontaneously describe their condition. Findings showed that negative perception of DED, delayed diagnosis and high frequency of treatment use were inter-related, and that all have a negative impact on patients' QoL. The generated language-specific keywords used to describe DED could serve as the basis for a comprehensive QoL questionnaire to be used in clinical settings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  1. Commentary on "The Perception and Cognition of Time in Balinese Music" by Andrew Clay McGraw

    Directory of Open Access Journals (Sweden)

    Ian Cross

    2008-05-01

    Full Text Available We review the paper by Andrew Clay McGraw, noting that it represents an interesting and valuable contribution to the study of music in cognition in its informed exploration of non-western musical perceptions. We raise a number of concerns about the methods used, and make suggestions as to how the issues that were empirically addressed in the paper might have been tackled in ways that would have enhanced the interpretability of its findings.

  2. On the number of neurons and time scale of integration underlying the formation of percepts in the brain.

    Science.gov (United States)

    Wohrer, Adrien; Machens, Christian K

    2015-03-01

    All of our perceptual experiences arise from the activity of neural populations. Here we study the formation of such percepts under the assumption that they emerge from a linear readout, i.e., a weighted sum of the neurons' firing rates. We show that this assumption constrains the trial-to-trial covariance structure of neural activities and animal behavior. The predicted covariance structure depends on the readout parameters, and in particular on the temporal integration window w and typical number of neurons K used in the formation of the percept. Using these predictions, we show how to infer the readout parameters from joint measurements of a subject's behavior and neural activities. We consider three such scenarios: (1) recordings from the complete neural population, (2) recordings of neuronal sub-ensembles whose size exceeds K, and (3) recordings of neuronal sub-ensembles that are smaller than K. Using theoretical arguments and artificially generated data, we show that the first two scenarios allow us to recover the typical spatial and temporal scales of the readout. In the third scenario, we show that the readout parameters can only be recovered by making additional assumptions about the structure of the full population activity. Our work provides the first thorough interpretation of (feed-forward) percept formation from a population of sensory neurons. We discuss applications to experimental recordings in classic sensory decision-making tasks, which will hopefully provide new insights into the nature of perceptual integration.

  3. Part-Time Undergraduate Nursing Students’ Perception and Attitude to ICT Supports for Distance Education in Nursing in Nigeria

    Directory of Open Access Journals (Sweden)

    Omolola Irinoye

    2016-04-01

    Full Text Available The increase in demand for university education remains unmet especially in developing countries; this has made adoption of distance education imperative in our educational system. Information and Communications Technology (ICT has been identified as a tool for improving education quality especially in developing countries. The study examined attitudes and perceptions of nursing students toward using Information and Communications Technology supports in distance education. A researchers‐designed and validated questionnaire with alpha coefficient of .82 was administered to 396 students of the Department of Nursing Science, Obafemi Awolowo University, Ile‐Ife, Nigeria out of which 305 (70% were returned. Findings of the study revealed that the majority of the nurses (83.3% had never attended any online computer based training program, a majority (63.9% had no formal computer training and do not possess personal computers, while 74.4% reported positive perception and attitudes toward using ICT supports in distance education. Lack of constant internet access was rated by the respondents (29.8% as a major challenge to e‐learning support. Gender and years of working experience had no significant influence on respondents’ attitudes and perceptions toward ICT supports.

  4. Tradable permit allocations and sequential choice

    Energy Technology Data Exchange (ETDEWEB)

    MacKenzie, Ian A. [Centre for Economic Research, ETH Zuerich, Zurichbergstrasse 18, 8092 Zuerich (Switzerland)

    2011-01-15

    This paper investigates initial allocation choices in an international tradable pollution permit market. For two sovereign governments, we compare allocation choices that are either simultaneously or sequentially announced. We show sequential allocation announcements result in higher (lower) aggregate emissions when announcements are strategic substitutes (complements). Whether allocation announcements are strategic substitutes or complements depends on the relationship between the follower's damage function and governments' abatement costs. When the marginal damage function is relatively steep (flat), allocation announcements are strategic substitutes (complements). For quadratic abatement costs and damages, sequential announcements provide a higher level of aggregate emissions. (author)

  5. Sequential Generalized Transforms on Function Space

    Directory of Open Access Journals (Sweden)

    Jae Gil Choi

    2013-01-01

    Full Text Available We define two sequential transforms on a function space Ca,b[0,T] induced by generalized Brownian motion process. We then establish the existence of the sequential transforms for functionals in a Banach algebra of functionals on Ca,b[0,T]. We also establish that any one of these transforms acts like an inverse transform of the other transform. Finally, we give some remarks about certain relations between our sequential transforms and other well-known transforms on Ca,b[0,T].

  6. Clinical evaluation of synthetic aperture sequential beamforming ultrasound in patients with liver tumors

    DEFF Research Database (Denmark)

    Hansen, Peter Møller; Hemmsen, Martin Christian; Brandt, Andreas Hjelm

    2014-01-01

    Medical ultrasound imaging using synthetic aperture sequential beamforming (SASB) has for the first time been used for clinical patient scanning. Nineteen patients with cancer of the liver (hepatocellular carcinoma or colorectal liver metastases) were scanned simultaneously with conventional...

  7. Detection of sequential activation of left atrium and coronary sinus musculature in the general population

    Directory of Open Access Journals (Sweden)

    Masaki Ota, MD

    2016-12-01

    Conclusions: Far-field LA potentials are often recorded in the CS during sequential LA and CSM activation in the general population. The timing of LA potentials in CS recordings reflected the direction of conduction across the CSM.

  8. Individual differences in the perception of melodic contours and pitch-accent timing in speech: Support for domain-generality of pitch processing.

    Science.gov (United States)

    Morrill, Tuuli H; McAuley, J Devin; Dilley, Laura C; Hambrick, David Z

    2015-08-01

    Do the same mechanisms underlie processing of music and language? Recent investigations of this question have yielded inconsistent results. Likely factors contributing to discrepant findings are use of small samples and failure to control for individual differences in cognitive ability. We investigated the relationship between music and speech prosody processing, while controlling for cognitive ability. Participants (n = 179) completed a battery of cognitive ability tests, the Montreal Battery of Evaluation of Amusia (MBEA) to assess music perception, and a prosody test of pitch peak timing discrimination (early, as in insight vs. late, incite). Structural equation modeling revealed that only music perception was a significant predictor of prosody test performance. Music perception accounted for 34.5% of variance on prosody test performance; cognitive abilities and music training added only about 8%. These results indicate musical pitch and temporal processing are highly predictive of pitch discrimination in speech processing, even after controlling for other possible predictors of this aspect of language processing. (c) 2015 APA, all rights reserved).

  9. Moving mesh generation with a sequential approach for solving PDEs

    DEFF Research Database (Denmark)

    In moving mesh methods, physical PDEs and a mesh equation derived from equidistribution of an error metrics (so-called the monitor function) are simultaneously solved and meshes are dynamically concentrated on steep regions (Lim et al., 2001). However, the simultaneous solution procedure...... a simple and robust moving mesh algorithm in one or multidimension. In this study, we propose a sequential solution procedure including two separate parts: prediction step to obtain an approximate solution to a next time level (integration of physical PDEs) and regriding step at the next time level (mesh...... generation and solution interpolation). Convection terms, which appear in physical PDEs and a mesh equation, are discretized by a WENO (Weighted Essentially Non-Oscillatory) scheme under the consrvative form. This sequential approach is to keep the advantages of robustness and simplicity for the static...

  10. Bidding in sequential electricity markets: The Nordic case

    DEFF Research Database (Denmark)

    Boomsma, Trine Krogh; Juul, Nina; Fleten, Stein-Erik

    2014-01-01

    problem as a multi-stage stochastic program. We investigate whether higher risk exposure can explain the hesitation, often observed in practice, to bid into the balancing market, even in cases of higher expected price levels. Furthermore, we quantify the gain from coordinated bidding, and by deriving......For electricity market participants trading in sequential markets with differences in price levels and risk exposure, coordinated bidding is highly relevant. We consider a Nordic power producer who engages in the day-ahead spot market and the near real-time balancing market. In both markets......, clearing prices and dispatched volumes are unknown at the time of bidding. However, in the balancing market, the agent faces an additional risk of not being dispatched. Taking into account the sequential clearing of these markets and the gradual realization of market prices, we formulate the bidding...

  11. Optimal Sequential Resource Sharing and Exchange in Multi-Agent Systems

    OpenAIRE

    Xiao, Yuanzhang

    2014-01-01

    Central to the design of many engineering systems and social networks is to solve the underlying resource sharing and exchange problems, in which multiple decentralized agents make sequential decisions over time to optimize some long-term performance metrics. It is challenging for the decentralized agents to make optimal sequential decisions because of the complicated coupling among the agents and across time. In this dissertation, we mainly focus on three important classes of multi-agent seq...

  12. Efficacy of premixed versus sequential administration of ...

    African Journals Online (AJOL)

    sequential administration in separate syringes on block characteristics, haemodynamic parameters, side effect profile and postoperative analgesic requirement. Trial design: This was a prospective, randomised clinical study. Method: Sixty orthopaedic patients scheduled for elective lower limb surgery under spinal ...

  13. “You Must Know Where You Come From”: South African Youths' Perceptions of Religion in Time of Social Change

    Science.gov (United States)

    Brittian, Aerika S.; Lewin, Nina; Norris, Shane A.

    2014-01-01

    This study examined South African youths' perceptions of religion during a period of social and economic transition. In-depth interviews were conducted with 55 Black South African youth (age 18) living in the Johannesburg-Soweto metropolitan area. Data were analyzed in a manner consistent with grounded theory methodology and structural coding. Beliefs about the function of religion were captured by the following themes: provides support, connection to the past, moral compass, promotes healthy development, and intersections between African traditional practices and Christian beliefs. Themes are discussed and directions for future research are presented. In addition, applications of the current research and implications for promoting youths' resilience are offered. PMID:24932064

  14. "You Must Know Where You Come From": South African Youths' Perceptions of Religion in Time of Social Change.

    Science.gov (United States)

    Brittian, Aerika S; Lewin, Nina; Norris, Shane A

    2013-11-01

    This study examined South African youths' perceptions of religion during a period of social and economic transition. In-depth interviews were conducted with 55 Black South African youth (age 18) living in the Johannesburg-Soweto metropolitan area. Data were analyzed in a manner consistent with grounded theory methodology and structural coding. Beliefs about the function of religion were captured by the following themes: provides support, connection to the past, moral compass, promotes healthy development, and intersections between African traditional practices and Christian beliefs. Themes are discussed and directions for future research are presented. In addition, applications of the current research and implications for promoting youths' resilience are offered.

  15. Sequential Detection of Thermophilic Lipase and Protease by Zymography.

    Science.gov (United States)

    Kurz, Liliana; Hernández, Zully; Contreras, Lellys M; Wilkesman, Jeff

    2017-01-01

    Lipase and protease present in cell-free fractions of thermophilic Bacillus sp. cultures were analyzed by polyacrylamide gel (PAG) electrophoresis. After run, the gel is electrotransferred to another PAG copolymerized with glycerol tributyrate, olive oil, and gelatin. This multi-substrate gel was incubated first for lipase detection, until bands appeared, and then stained with Coomassie for protease detection. Advantages of this sequential procedure are the detection of two different enzyme activities on a single PAG, beside time and resource saving.

  16. Models of sequential decision making in consumer lending

    OpenAIRE

    Kanshukan Rajaratnam; Peter A. Beling; George A. Overstreet

    2016-01-01

    Abstract In this paper, we introduce models of sequential decision making in consumer lending. From the definition of adverse selection in static lending models, we show that homogenous borrowers take-up offers at different instances of time when faced with a sequence of loan offers. We postulate that bounded rationality and diverse decision heuristics used by consumers drive the decisions they make about credit offers. Under that postulate, we show how observation of early decisions in a seq...

  17. MUF residuals tested by a sequential test with power one

    International Nuclear Information System (INIS)

    Sellinschegg, D.; Bicking, U.

    1983-01-01

    Near-real-time material accountancy is an ongoing safeguards development to extend the current capability of IAEA safeguards. The evaluation of the observed ''Material Unaccounted For'' (MUF) time series is an important part in a near-real-time material accountancy regime. The maximum capability of a sequential data evaluation procedure is demonstrated by applying this procedure to the material balance area of the chemical separation process of a reference reprocessing facility with a throughput of 1000 tonnes heavy metal per year, as an example. It is shown that, compared to a conventional material accountancy approach, the detection time as well as the detection probability is significantly improved. (author)

  18. Structural Consistency, Consistency, and Sequential Rationality.

    OpenAIRE

    Kreps, David M; Ramey, Garey

    1987-01-01

    Sequential equilibria comprise consistent beliefs and a sequentially ra tional strategy profile. Consistent beliefs are limits of Bayes ratio nal beliefs for sequences of strategies that approach the equilibrium strategy. Beliefs are structurally consistent if they are rationaliz ed by some single conjecture concerning opponents' strategies. Consis tent beliefs are not necessarily structurally consistent, notwithstan ding a claim by Kreps and Robert Wilson (1982). Moreover, the spirit of stru...

  19. What’s going on at the bus stop? The impact of Auckland’s real time passenger information system on patrons timespace perceptions

    Directory of Open Access Journals (Sweden)

    Phillipa Mitchell

    2016-09-01

    Full Text Available Transport innovations have predominantly been recognised for their power to alter geographic space through time space compression. The emergence of Intelligent Transport Systems provides an interesting new lens through which to investigate individuals’ perceptions and constitution of time and space. This paper focuses on one of these systems, the Real Time Passenger Information Signal Pre-emption System (RTPISP System currently being installed in Auckland, New Zealand. It explores how individuals’ travel experiences are being shaped by interface the RTPISP System provides between the ubiquitous computing background and individuals’ everyday lives. This paper proposes that such technologies are causing more than just the compression of space by time. By embedding the mundane activity of catching the bus in the coded spaces of the RTPISP System new conditions of possibility are emerging allowing these bus patrons to constitute alternative timespaces while waiting for the bus, timespaces which they previously were unable or unwilling to access.

  20. Sequential acquisition of mutations in myelodysplastic syndromes.

    Science.gov (United States)

    Makishima, Hideki

    2017-01-01

    Recent progress in next-generation sequencing technologies allows us to discover frequent mutations throughout the coding regions of myelodysplastic syndromes (MDS), potentially providing us with virtually a complete spectrum of driver mutations in this disease. As shown by many study groups these days, such driver mutations are acquired in a gene-specific fashion. For instance, DDX41 mutations are observed in germline cells long before MDS presentation. In blood samples from healthy elderly individuals, somatic DNMT3A and TET2 mutations are detected as age-related clonal hematopoiesis and are believed to be a risk factor for hematological neoplasms. In MDS, mutations of genes such as NRAS and FLT3, designated as Type-1 genes, may be significantly associated with leukemic evolution. Another type (Type-2) of genes, including RUNX1 and GATA2, are related to progression from low-risk to high-risk MDS. Overall, various driver mutations are sequentially acquired in MDS, at a specific time, in either germline cells, normal hematopoietic cells, or clonal MDS cells.

  1. Programme for test generation for combinatorial and sequential systems

    International Nuclear Information System (INIS)

    Tran Huy Hoan

    1973-01-01

    This research thesis reports the computer-assisted search for tests aimed at failure detection in combinatorial and sequential logic circuits. As he wants to deal with complex circuits with many modules such as those met in large scale integrated circuits (LSI), the author used propagation paths. He reports the development of a method which is valid for combinatorial systems and for several sequential circuits comprising elementary logic modules and JK and RS flip-flops. This method is developed on an IBM 360/91 computer in PL/1 language. The used memory space is limited and adjustable with respect to circuit dimension. Computing time is short when compared to that needed by other programmes. The solution is practical and efficient for failure test and localisation

  2. Comparisons of memory for nonverbal auditory and visual sequential stimuli.

    Science.gov (United States)

    McFarland, D J; Cacace, A T

    1995-01-01

    Properties of auditory and visual sensory memory were compared by examining subjects' recognition performance of randomly generated binary auditory sequential frequency patterns and binary visual sequential color patterns within a forced-choice paradigm. Experiment 1 demonstrated serial-position effects in auditory and visual modalities consisting of both primacy and recency effects. Experiment 2 found that retention of auditory and visual information was remarkably similar when assessed across a 10s interval. Experiments 3 and 4, taken together, showed that the recency effect in sensory memory is affected more by the type of response required (recognition vs. reproduction) than by the sensory modality employed. These studies suggest that auditory and visual sensory memory stores for nonverbal stimuli share similar properties with respect to serial-position effects and persistence over time.

  3. Safeguarding a Lunar Rover with Wald's Sequential Probability Ratio Test

    Science.gov (United States)

    Furlong, Michael; Dille, Michael; Wong, Uland; Nefian, Ara

    2016-01-01

    The virtual bumper is a safeguarding mechanism for autonomous and remotely operated robots. In this paper we take a new approach to the virtual bumper system by using an old statistical test. By using a modified version of Wald's sequential probability ratio test we demonstrate that we can reduce the number of false positive reported by the virtual bumper, thereby saving valuable mission time. We use the concept of sequential probability ratio to control vehicle speed in the presence of possible obstacles in order to increase certainty about whether or not obstacles are present. Our new algorithm reduces the chances of collision by approximately 98 relative to traditional virtual bumper safeguarding without speed control.

  4. Lateralized speech perception with small interaural time differences in normal-hearing and hearing-impaired listeners

    DEFF Research Database (Denmark)

    Locsei, Gusztav; Santurette, Sébastien; Dau, Torsten

    2017-01-01

    and two-talker babble in terms of SRTs, HI listeners could utilize ITDs to a similar degree as NH listeners to facilitate the binaural unmasking of speech. A slight difference was observed between the group means when target and maskers were separated from each other by large ITDs, but not when separated...... SRMs are elicited by small ITDs. Speech reception thresholds (SRTs) and SRM due to ITDs were measured over headphones for 10 young NH and 10 older HI listeners, who had normal or close-to-normal hearing below 1.5 kHz. Diotic target sentences were presented in diotic or dichotic speech-shaped noise...... or two-talker babble maskers. In the dichotic conditions, maskers were lateralized by delaying the masker waveforms in the left headphone channel. Multiple magnitudes of masker ITDs were tested in both noise conditions. Although deficits were observed in speech perception abilities in speechshaped noise...

  5. Cortical responses following simultaneous and sequential retinal neurostimulation with different return configurations.

    Science.gov (United States)

    Barriga-Rivera, Alejandro; Morley, John W; Lovell, Nigel H; Suaning, Gregg J

    2016-08-01

    Researchers continue to develop visual prostheses towards safer and more efficacious systems. However limitations still exist in the number of stimulating channels that can be integrated. Therefore there is a need for spatial and time multiplexing techniques to provide improved performance of the current technology. In particular, bright and high-contrast visual scenes may require simultaneous activation of several electrodes. In this research, a 24-electrode array was suprachoroidally implanted in three normally-sighted cats. Multi-unit activity was recorded from the primary visual cortex. Four stimulation strategies were contrasted to provide activation of seven electrodes arranged hexagonally: simultaneous monopolar, sequential monopolar, sequential bipolar and hexapolar. Both monopolar configurations showed similar cortical activation maps. Hexapolar and sequential bipolar configurations activated a lower number of cortical channels. Overall, the return configuration played a more relevant role in cortical activation than time multiplexing and thus, rapid sequential stimulation may assist in reducing the number of channels required to activate large retinal areas.

  6. Efficient sequential and parallel algorithms for record linkage.

    Science.gov (United States)

    Mamun, Abdullah-Al; Mi, Tian; Aseltine, Robert; Rajasekaran, Sanguthevar

    2014-01-01

    Integrating data from multiple sources is a crucial and challenging problem. Even though there exist numerous algorithms for record linkage or deduplication, they suffer from either large time needs or restrictions on the number of datasets that they can integrate. In this paper we report efficient sequential and parallel algorithms for record linkage which handle any number of datasets and outperform previous algorithms. Our algorithms employ hierarchical clustering algorithms as the basis. A key idea that we use is radix sorting on certain attributes to eliminate identical records before any further processing. Another novel idea is to form a graph that links similar records and find the connected components. Our sequential and parallel algorithms have been tested on a real dataset of 1,083,878 records and synthetic datasets ranging in size from 50,000 to 9,000,000 records. Our sequential algorithm runs at least two times faster, for any dataset, than the previous best-known algorithm, the two-phase algorithm using faster computation of the edit distance (TPA (FCED)). The speedups obtained by our parallel algorithm are almost linear. For example, we get a speedup of 7.5 with 8 cores (residing in a single node), 14.1 with 16 cores (residing in two nodes), and 26.4 with 32 cores (residing in four nodes). We have compared the performance of our sequential algorithm with TPA (FCED) and found that our algorithm outperforms the previous one. The accuracy is the same as that of this previous best-known algorithm.

  7. Results of simultaneous and sequential pediatric liver and kidney transplantation.

    Science.gov (United States)

    Rogers, J; Bueno, J; Shapiro, R; Scantlebury, V; Mazariegos, G; Fung, J; Reyes, J

    2001-11-27

    (86%) of seven sequentially transplanted kidneys developed acute cellular rejection compared with only two (25%) of eight simultaneously transplanted kidneys (P<0.04). Simultaneously transplanted kidneys were less likely to develop rejection than sequentially transplanted kidneys in this series. This did not have any bearing on patient or graft survival rates. Mortality correlated directly with the severity of United Network of Organ Sharing status at the time of kidney transplantation. Candidates for simultaneous or sequential LTx/KTx should be prioritized based on medical stability to optimize distribution of scarce renal allografts.

  8. The effect of lineup member similarity on recognition accuracy in simultaneous and sequential lineups

    OpenAIRE

    Flowe, Heather D.

    2005-01-01

    Prior research suggests that simultaneous lineup procedures, which involve presenting at once all of the alternatives, encourage witnesses to identify the relatively most familiar face. In contrast, when lineup alternatives are evaluated one at a time, or sequentially, identifying a face is not influenced by previously seen faces in the lineup. Instead, a face will be chosen from a sequential lineup only when it is a sufficient match to the perpetrator in memory. The present study investigate...

  9. Simple and flexible SAS and SPSS programs for analyzing lag-sequential categorical data.

    Science.gov (United States)

    O'Connor, B P

    1999-11-01

    This paper describes simple and flexible programs for analyzing lag-sequential categorical data, using SAS and SPSS. The programs read a stream of codes and produce a variety of lag-sequential statistics, including transitional frequencies, expected transitional frequencies, transitional probabilities, adjusted residuals, z values, Yule's Q values, likelihood ratio tests of stationarity across time and homogeneity across groups or segments, transformed kappas for unidirectional dependence, bidirectional dependence, parallel and nonparallel dominance, and significance levels based on both parametric and randomization tests.

  10. Competitive interactions affect working memory performance for both simultaneous and sequential stimulus presentation

    OpenAIRE

    Ahmad, J; Swan, G; Bowman, H; Wyble, B; De Ozorio Nobre, AC; Shapiro, KL; McNab, F

    2017-01-01

    Competition between simultaneously presented visual stimuli lengthens reaction time and reduces both the BOLD response and neural firing. In contrast, conditions of sequential presentation have been assumed to be free from competition. Here we manipulated the spatial proximity of stimuli (Near versus Far conditions) to examine the effects of simultaneous and sequential competition on different measures of working memory (WM) for colour. With simultaneous presentation, the measure of WM precis...

  11. Comparing a motivational and a self-regulatory intervention to adopt an oral self-care regimen: a two-sequential randomized crossover trial.

    Science.gov (United States)

    Lhakhang, Pempa; Gholami, Maryam; Knoll, Nina; Schwarzer, Ralf

    2015-01-01

    A sequential intervention to facilitate the adoption and maintenance of dental flossing was conducted among 205 students in India, aged 18-26 years. Two experimental groups received different treatment sequences and were observed at three assessment points, 34 days apart. One group received first a motivational intervention (intention, outcome expectancies, and risk perception, followed by a self-regulatory intervention (planning, self-efficacy, and action control). The second group received the same intervention in the opposite order. Both intervention sequences yielded gains in terms of flossing, planning, self-efficacy, and action control. However, at Time 2, those who had received the self-regulatory intervention first, were superior to their counterparts who had received the motivational intervention first. At Time 3, differences vanished as everyone had then received both interventions. Thus, findings highlight the benefits of a self-regulatory compared to a mere motivational intervention.

  12. Accurately controlled sequential self-folding structures by polystyrene film

    Science.gov (United States)

    Deng, Dongping; Yang, Yang; Chen, Yong; Lan, Xing; Tice, Jesse

    2017-08-01

    Four-dimensional (4D) printing overcomes the traditional fabrication limitations by designing heterogeneous materials to enable the printed structures evolve over time (the fourth dimension) under external stimuli. Here, we present a simple 4D printing of self-folding structures that can be sequentially and accurately folded. When heated above their glass transition temperature pre-strained polystyrene films shrink along the XY plane. In our process silver ink traces printed on the film are used to provide heat stimuli by conducting current to trigger the self-folding behavior. The parameters affecting the folding process are studied and discussed. Sequential folding and accurately controlled folding angles are achieved by using printed ink traces and angle lock design. Theoretical analyses are done to guide the design of the folding processes. Programmable structures such as a lock and a three-dimensional antenna are achieved to test the feasibility and potential applications of this method. These self-folding structures change their shapes after fabrication under controlled stimuli (electric current) and have potential applications in the fields of electronics, consumer devices, and robotics. Our design and fabrication method provides an easy way by using silver ink printed on polystyrene films to 4D print self-folding structures for electrically induced sequential folding with angular control.

  13. Immediately sequential bilateral cataract surgery: advantages and disadvantages.

    Science.gov (United States)

    Singh, Ranjodh; Dohlman, Thomas H; Sun, Grace

    2017-01-01

    The number of cataract surgeries performed globally will continue to rise to meet the needs of an aging population. This increased demand will require healthcare systems and providers to find new surgical efficiencies while maintaining excellent surgical outcomes. Immediately sequential bilateral cataract surgery (ISBCS) has been proposed as a solution and is increasingly being performed worldwide. The purpose of this review is to discuss the advantages and disadvantages of ISBCS. When appropriate patient selection occurs and guidelines are followed, ISBCS is comparable with delayed sequential bilateral cataract surgery in long-term patient satisfaction, visual acuity and complication rates. In addition, the risk of bilateral postoperative endophthalmitis and concerns of poorer refractive outcomes have not been supported by the literature. ISBCS is cost-effective for the patient, healthcare payors and society, but current reimbursement models in many countries create significant financial barriers for facilities and surgeons. As demand for cataract surgery rises worldwide, ISBCS will become increasingly important as an alternative to delayed sequential bilateral cataract surgery. Advantages include potentially decreased wait times for surgery, patient convenience and cost savings for healthcare payors. Although they are comparable in visual acuity and complication rates, hurdles that prevent wide adoption include liability concerns as ISBCS is not an established standard of care, economic constraints for facilities and surgeons and inability to fine-tune intraocular lens selection in the second eye. Given these considerations, an open discussion regarding the advantages and disadvantages of ISBCS is important for appropriate patient selection.

  14. A node linkage approach for sequential pattern mining.

    Directory of Open Access Journals (Sweden)

    Osvaldo Navarro

    Full Text Available Sequential Pattern Mining is a widely addressed problem in data mining, with applications such as analyzing Web usage, examining purchase behavior, and text mining, among others. Nevertheless, with the dramatic increase in data volume, the current approaches prove inefficient when dealing with large input datasets, a large number of different symbols and low minimum supports. In this paper, we propose a new sequential pattern mining algorithm, which follows a pattern-growth scheme to discover sequential patterns. Unlike most pattern growth algorithms, our approach does not build a data structure to represent the input dataset, but instead accesses the required sequences through pseudo-projection databases, achieving better runtime and reducing memory requirements. Our algorithm traverses the search space in a depth-first fashion and only preserves in memory a pattern node linkage and the pseudo-projections required for the branch being explored at the time. Experimental results show that our new approach, the Node Linkage Depth-First Traversal algorithm (NLDFT, has better performance and scalability in comparison with state of the art algorithms.

  15. Stream/Bounce Event Perception Reveals a Temporal Limit of Motion Correspondence Based on Surface Feature over Space and Time

    Directory of Open Access Journals (Sweden)

    Yousuke Kawachi

    2011-06-01

    Full Text Available We examined how stream/bounce event perception is affected by motion correspondence based on the surface features of moving objects passing behind an occlusion. In the stream/bounce display two identical objects moving across each other in a two-dimensional display can be perceived as either streaming through or bouncing off each other at coincidence. Here, surface features such as colour (Experiments 1 and 2 or luminance (Experiment 3 were switched between the two objects at coincidence. The moment of coincidence was invisible to observers due to an occluder. Additionally, the presentation of the moving objects was manipulated in duration after the feature switch at coincidence. The results revealed that a postcoincidence duration of approximately 200 ms was required for the visual system to stabilize judgments of stream/bounce events by determining motion correspondence between the objects across the occlusion on the basis of the surface feature. The critical duration was similar across motion speeds of objects and types of surface features. Moreover, controls (Experiments 4a–4c showed that cognitive bias based on feature (colour/luminance congruency across the occlusion could not fully account for the effects of surface features on the stream/bounce judgments. We discuss the roles of motion correspondence, visual feature processing, and attentive tracking in the stream/bounce judgments.

  16. Patients' perceptions of cosmetic surgery at a time of globalization, medical consumerism, and mass media culture: a French experience.

    Science.gov (United States)

    Lazar, Câlin Constantin; Deneuve, Sophie

    2013-08-01

    The global popularity of cosmetic surgery, combined with mass media attention on medical consumerism, has resulted in misinformation that may have negatively affected the "collective image" of aesthetic practitioners. The authors assess patients' perceptions of cosmetic surgery and analyze their decision-making processes. During a 2-year period, 250 consecutive patients presenting to either of 2 public hospitals for cosmetic surgery treatment were asked to complete a 7-item questionnaire evaluating their knowledge of opinions about, and referring practices for, aesthetic procedures. Patients undergoing oncologic, postbariatric, or reconstructive procedures were not included in the study. After exclusion of 71 cases for refusal or incompletion, 179 questionnaires were retained and analyzed (from 162 women and 17 men). Overall, repair (70.4%), comfort (45.3%), and health (40.8%) were the words most frequently associated with cosmetic surgery. Quality of preoperative information (69.3%), patient-physician relationship (65.4%), and results seen in relatives/friends (46.3%) were the most important criteria for selecting a cosmetic surgeon. Moreover, 82.7% of patients knew the difference between cosmetic surgery and cosmetic medicine. Although potential patients appear to be more educated about cosmetic surgery than they were several years ago, misinformation still persists. As physicians, we must be responsible for disseminating accurate education and strengthening our collaboration with general practitioners to improve not only our results but also the accuracy of information in the mass media.

  17. BACKGROUND MUSIC AT THE TIME OF ACADEMIC ASSESSMENT AS STRESS BUSTER: PERCEPTION OF THE STUDENTS AT GOVT. MEDICAL COLLEGE , BILASPUR

    Directory of Open Access Journals (Sweden)

    Atul Manoharrao

    2015-09-01

    Full Text Available Music has numerous applications within a clinical setting. It can be in the form of background music too. It is known that some students study and learn more effectively while listening to music. METHODS: The present study was intended to evaluate the perception of the students at medical college for the innovative idea of playing of background music during examination as a stress buster and their response for including it as one of the measure for reducing the stress among medical students. RESULT: The subjects were divided into three groups on t he basis of suffering from anxiety and stress during examination – No Anxiety (N, Occasional Anxiety (O, Anxiety (A. The groups were subjected to Spearman Correlation (SPSS. When the No Anxiety (N group and Occasional Anxiety (O group were compared, it showed positive correlation (0.482, but failed to show statistical significance [0.189]. However, the comparison of the Occasional Anxiety (O group and Anxiety (A group showed positive correlation (0.873 which was statistically significant. CONCLUSI ON: This study indicates that it is the innovative idea of playing background music liked by most of students and even may reduce anxiety and stress which is likely to improve performance. We are encouraged with the positive trends and results of the study

  18. Optimisation of beryllium-7 gamma analysis following BCR sequential extraction

    International Nuclear Information System (INIS)

    Taylor, A.; Blake, W.H.; Keith-Roach, M.J.

    2012-01-01

    Graphical abstract: Showing decrease in analytical uncertainty using the optimal (combined preconcentrated sample extract) method. nv (no value) where extract activities were 7 Be geochemical behaviour is required to support tracer studies. ► Sequential extraction with natural 7 Be returns high analytical uncertainties. ► Preconcentrating extracts from a large sample mass improved analytical uncertainty. ► This optimised method can be readily employed in studies using low activity samples. - Abstract: The application of cosmogenic 7 Be as a sediment tracer at the catchment-scale requires an understanding of its geochemical associations in soil to underpin the assumption of irreversible adsorption. Sequential extractions offer a readily accessible means of determining the associations of 7 Be with operationally defined soil phases. However, the subdivision of the low activity concentrations of fallout 7 Be in soils into geochemical fractions can introduce high gamma counting uncertainties. Extending analysis time significantly is not always an option for batches of samples, owing to the on-going decay of 7 Be (t 1/2 = 53.3 days). Here, three different methods of preparing and quantifying 7 Be extracted using the optimised BCR three-step scheme have been evaluated and compared with a focus on reducing analytical uncertainties. The optimal method involved carrying out the BCR extraction in triplicate, sub-sampling each set of triplicates for stable Be analysis before combining each set and coprecipitating the 7 Be with metal oxyhydroxides to produce a thin source for gamma analysis. This method was applied to BCR extractions of natural 7 Be in four agricultural soils. The approach gave good counting statistics from a 24 h analysis period (∼10% (2σ) where extract activity >40% of total activity) and generated statistically useful sequential extraction profiles. Total recoveries of 7 Be fell between 84 and 112%. The stable Be data demonstrated that the

  19. Synthetic Aperture Sequential Beamforming implemented on multi-core platforms

    DEFF Research Database (Denmark)

    Kjeldsen, Thomas; Lassen, Lee; Hemmsen, Martin Christian

    2014-01-01

    This paper compares several computational ap- proaches to Synthetic Aperture Sequential Beamforming (SASB) targeting consumer level parallel processors such as multi-core CPUs and GPUs. The proposed implementations demonstrate that ultrasound imaging using SASB can be executed in real- time with ...... per second) on an Intel Core i7 2600 CPU with an AMD HD7850 and a NVIDIA GTX680 GPU. The fastest CPU and GPU implementations use 14% and 1.3% of the real-time budget of 62 ms/frame, respectively. The maximum achieved processing rate is 1265 frames/s....

  20. Dihydroazulene photoswitch operating in sequential tunneling regime

    DEFF Research Database (Denmark)

    Broman, Søren Lindbæk; Lara-Avila, Samuel; Thisted, Christine Lindbjerg

    2012-01-01

    to electrodes so that the electron transport goes by sequential tunneling. To assure weak coupling, the DHA switching kernel is modified by incorporating p-MeSC6H4 end-groups. Molecules are prepared by Suzuki cross-couplings on suitable halogenated derivatives of DHA. The synthesis presents an expansion of our......, incorporating a p-MeSC6H4 anchoring group in one end, has been placed in a silver nanogap. Conductance measurements justify that transport through both DHA (high resistivity) and VHF (low resistivity) forms goes by sequential tunneling. The switching is fairly reversible and reenterable; after more than 20 ON...

  1. Asynchronous Operators of Sequential Logic Venjunction & Sequention

    CERN Document Server

    Vasyukevich, Vadim

    2011-01-01

    This book is dedicated to new mathematical instruments assigned for logical modeling of the memory of digital devices. The case in point is logic-dynamical operation named venjunction and venjunctive function as well as sequention and sequentional function. Venjunction and sequention operate within the framework of sequential logic. In a form of the corresponding equations, they organically fit analytical expressions of Boolean algebra. Thus, a sort of symbiosis is formed using elements of asynchronous sequential logic on the one hand and combinational logic on the other hand. So, asynchronous

  2. Scale construction for measuring adolescent boys' and girls' attitudes, beliefs, perception of control, and intention to engage in leisure-time physical activity.

    Science.gov (United States)

    Kerner, Matthew S; Kalinski, Michael I

    2002-08-01

    Using the Theory of Planned Behavior as a framework, the Attitude to Leisure-time Physical Activity, Expectations of Others, Perceived Control, and Intention of Engage in Leisure-time Physical Activity scales were developed for use among high school students. The study population included 20 boys and 68 girls 13 to 17 years of age (for boys, M = 15.1 yr., SD = 1.0; for girls, M = 15.0 yr., SD = 1.1). Generation of items and the establishment of content validity were performed by professionals in exercise physiology, physical education, and clinical psychology. Each scale item was phrased in a Likert-type format. Both unipolar and bipolar scales with seven response choices were developed. Following the pilot testing and subsequent revisions, 32 items were retained in the Attitude to Leisure-time Physical Activity scale, 10 items were retained in the Expectations of Others scale, 3 items were retained in the Perceived Control Scale, and 24 items were retained in the Intention to Engage in Leisure-time Physical Activity scale. Coefficients indicated adequate stability and internal consistency with alpha ranging from .81 to .96. Studies of validities are underway, after which scales would be made available to those interested in intervention techniques for promoting positive attitudes toward physical fitness, perception of control over engaging in leisure-time physical activities, and good intentions to engage in leisure-time physical activities. The present results are encouraging.

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

    Science.gov (United States)

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

    2007-01-01

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

  4. Is it Time for a Sudden Infant Death Syndrome (SIDS) Awareness Campaign? Community Stakeholders' Perceptions of SIDS.

    Science.gov (United States)

    Gollenberg, Audra; Fendley, Kim

    2018-01-01

    Sudden infant death syndrome (SIDS) remains a leading cause of infant death in the United States and in Virginia, the SIDS rate is higher than the national average. We sought to gauge the perceptions among community-identified stakeholders as to community resource needs to reduce SIDS. We used snowball sampling to identify important community stakeholders to be interviewed as key informants. A semi-structured interview lasting 45 min-2 hours was delivered to determine resource needs to reduce SIDS, and whether high-risk community members were aware of SIDS risk factors among stakeholders representing a variety of disciplines. Interviews were conducted in two geographic areas with higher than average rates of infant mortality, an urban district, Winchester City, VA and a rural district, Page County, VA. A total of 74 interviews were completed with stakeholders in healthcare, health departments, social services, law enforcement, education/childcare, faith-based institutions, non-profit agencies and non-affiliated community members. The majority of respondents perceive that high-risk community members are not aware of factors that can lead to SIDS (50%). Participants suggested that more "education" is needed to further reduce the rates of SIDS in their communities (73%). Respondents detailed that more pervasive, strategic, and multi-channeled education is necessary to reduce cases of SIDS. Community leaders perceive that high-risk community members are not fully aware of risk factors that can lead to SIDS. Maternal/child health stakeholders in these Virginia locales suggested more community-based education as a potential solution to SIDS.

  5. Cost-effectiveness of simultaneous versus sequential surgery in head and neck reconstruction.

    Science.gov (United States)

    Wong, Kevin K; Enepekides, Danny J; Higgins, Kevin M

    2011-02-01

    To determine whether simultaneous (ablation and reconstruction overlaps by two teams) head and neck reconstruction is cost effective compared to sequentially (ablation followed by reconstruction) performed surgery. Case-controlled study. Tertiary care hospital. Oncology patients undergoing free flap reconstruction of the head and neck. A match paired comparison study was performed with a retrospective chart review examining the total time of surgery for sequential and simultaneous surgery. Nine patients were selected for both the sequential and simultaneous groups. Sequential head and neck reconstruction patients were pair matched with patients who had undergone similar oncologic ablative or reconstructive procedures performed in a simultaneous fashion. A detailed cost analysis using the microcosting method was then undertaken looking at the direct costs of the surgeons, anesthesiologist, operating room, and nursing. On average, simultaneous surgery required 3 hours 15 minutes less operating time, leading to a cost savings of approximately $1200/case when compared to sequential surgery. This represents approximately a 15% reduction in the cost of the entire operation. Simultaneous head and neck reconstruction is more cost effective when compared to sequential surgery.

  6. Eyewitness confidence in simultaneous and sequential lineups: a criterion shift account for sequential mistaken identification overconfidence.

    Science.gov (United States)

    Dobolyi, David G; Dodson, Chad S

    2013-12-01

    Confidence judgments for eyewitness identifications play an integral role in determining guilt during legal proceedings. Past research has shown that confidence in positive identifications is strongly associated with accuracy. Using a standard lineup recognition paradigm, we investigated accuracy using signal detection and ROC analyses, along with the tendency to choose a face with both simultaneous and sequential lineups. We replicated past findings of reduced rates of choosing with sequential as compared to simultaneous lineups, but notably found an accuracy advantage in favor of simultaneous lineups. Moreover, our analysis of the confidence-accuracy relationship revealed two key findings. First, we observed a sequential mistaken identification overconfidence effect: despite an overall reduction in false alarms, confidence for false alarms that did occur was higher with sequential lineups than with simultaneous lineups, with no differences in confidence for correct identifications. This sequential mistaken identification overconfidence effect is an expected byproduct of the use of a more conservative identification criterion with sequential than with simultaneous lineups. Second, we found a steady drop in confidence for mistaken identifications (i.e., foil identifications and false alarms) from the first to the last face in sequential lineups, whereas confidence in and accuracy of correct identifications remained relatively stable. Overall, we observed that sequential lineups are both less accurate and produce higher confidence false identifications than do simultaneous lineups. Given the increasing prominence of sequential lineups in our legal system, our data argue for increased scrutiny and possibly a wholesale reevaluation of this lineup format. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  7. Time-sequential changes of differentially expressed miRNAs during the process of anterior lumbar interbody fusion using equine bone protein extract, rhBMP-2 and autograft

    Science.gov (United States)

    Chen, Da-Fu; Zhou, Zhi-Yu; Dai, Xue-Jun; Gao, Man-Man; Huang, Bao-Ding; Liang, Tang-Zhao; Shi, Rui; Zou, Li-Jin; Li, Hai-Sheng; Bünger, Cody; Tian, Wei; Zou, Xue-Nong

    2014-03-01

    The precise mechanism of bone regeneration in different bone graft substitutes has been well studied in recent researches. However, miRNAs regulation of the bone formation has been always mysterious. We developed the anterior lumbar interbody fusion (ALIF) model in pigs using equine bone protein extract (BPE), recombinant human bone morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge (ACS), and autograft as bone graft substitute, respectively. The miRNA and gene expression profiles of different bone graft materials were examined using microarray technology and data analysis, including self-organizing maps, KEGG pathway and Biological process GO analyses. We then jointly analyzed miRNA and mRNA profiles of the bone fusion tissue at different time points respectively. Results showed that miRNAs, including let-7, miR-129, miR-21, miR-133, miR-140, miR-146, miR-184, and miR-224, were involved in the regulation of the immune and inflammation response, which provided suitable inflammatory microenvironment for bone formation. At late stage, several miRNAs directly regulate SMAD4, Estrogen receptor 1 and 5-hydroxytryptamine (serotonin) receptor 2C for bone formation. It can be concluded that miRNAs play important roles in balancing the inflammation and bone formation.

  8. Interpretability degrees of finitely axiomatized sequential theories

    NARCIS (Netherlands)

    Visser, Albert

    In this paper we show that the degrees of interpretability of finitely axiomatized extensions-in-the-same-language of a finitely axiomatized sequential theory-like Elementary Arithmetic EA, IΣ1, or the Gödel-Bernays theory of sets and classes GB-have suprema. This partially answers a question posed

  9. Interpretability Degrees of Finitely Axiomatized Sequential Theories

    NARCIS (Netherlands)

    Visser, Albert

    2012-01-01

    In this paper we show that the degrees of interpretability of finitely axiomatized extensions-in-the-same-language of a finitely axiomatized sequential theory —like Elementary Arithmetic EA, IΣ1, or the Gödel-Bernays theory of sets and classes GB— have suprema. This partially answers a question

  10. S.M.P. SEQUENTIAL MATHEMATICS PROGRAM.

    Science.gov (United States)

    CICIARELLI, V; LEONARD, JOSEPH

    A SEQUENTIAL MATHEMATICS PROGRAM BEGINNING WITH THE BASIC FUNDAMENTALS ON THE FOURTH GRADE LEVEL IS PRESENTED. INCLUDED ARE AN UNDERSTANDING OF OUR NUMBER SYSTEM, AND THE BASIC OPERATIONS OF WORKING WITH WHOLE NUMBERS--ADDITION, SUBTRACTION, MULTIPLICATION, AND DIVISION. COMMON FRACTIONS ARE TAUGHT IN THE FIFTH, SIXTH, AND SEVENTH GRADES. A…

  11. Sequential and Simultaneous Logit: A Nested Model.

    NARCIS (Netherlands)

    van Ophem, J.C.M.; Schram, A.J.H.C.

    1997-01-01

    A nested model is presented which has both the sequential and the multinomial logit model as special cases. This model provides a simple test to investigate the validity of these specifications. Some theoretical properties of the model are discussed. In the analysis a distribution function is

  12. Sensitivity Analysis in Sequential Decision Models.

    Science.gov (United States)

    Chen, Qiushi; Ayer, Turgay; Chhatwal, Jagpreet

    2017-02-01

    Sequential decision problems are frequently encountered in medical decision making, which are commonly solved using Markov decision processes (MDPs). Modeling guidelines recommend conducting sensitivity analyses in decision-analytic models to assess the robustness of the model results against the uncertainty in model parameters. However, standard methods of conducting sensitivity analyses cannot be directly applied to sequential decision problems because this would require evaluating all possible decision sequences, typically in the order of trillions, which is not practically feasible. As a result, most MDP-based modeling studies do not examine confidence in their recommended policies. In this study, we provide an approach to estimate uncertainty and confidence in the results of sequential decision models. First, we provide a probabilistic univariate method to identify the most sensitive parameters in MDPs. Second, we present a probabilistic multivariate approach to estimate the overall confidence in the recommended optimal policy considering joint uncertainty in the model parameters. We provide a graphical representation, which we call a policy acceptability curve, to summarize the confidence in the optimal policy by incorporating stakeholders' willingness to accept the base case policy. For a cost-effectiveness analysis, we provide an approach to construct a cost-effectiveness acceptability frontier, which shows the most cost-effective policy as well as the confidence in that for a given willingness to pay threshold. We demonstrate our approach using a simple MDP case study. We developed a method to conduct sensitivity analysis in sequential decision models, which could increase the credibility of these models among stakeholders.

  13. Sequential models for coarsening and missingness

    NARCIS (Netherlands)

    Gill, R.D.; Robins, J.M.

    1997-01-01

    In a companion paper we described what intuitively would seem to be the most general possible way to generate Coarsening at Random mechanisms a sequential procedure called randomized monotone coarsening Counterexamples showed that CAR mechanisms exist which cannot be represented in this way Here we

  14. Sequential decoders for large MIMO systems

    KAUST Repository

    Ali, Konpal S.; Abediseid, Walid; Alouini, Mohamed-Slim

    2014-01-01

    the Sequential Decoder using the Fano Algorithm for large MIMO systems. A parameter called the bias is varied to attain different performance-complexity trade-offs. Low values of the bias result in excellent performance but at the expense of high complexity

  15. Classical and sequential limit analysis revisited

    Science.gov (United States)

    Leblond, Jean-Baptiste; Kondo, Djimédo; Morin, Léo; Remmal, Almahdi

    2018-04-01

    Classical limit analysis applies to ideal plastic materials, and within a linearized geometrical framework implying small displacements and strains. Sequential limit analysis was proposed as a heuristic extension to materials exhibiting strain hardening, and within a fully general geometrical framework involving large displacements and strains. The purpose of this paper is to study and clearly state the precise conditions permitting such an extension. This is done by comparing the evolution equations of the full elastic-plastic problem, the equations of classical limit analysis, and those of sequential limit analysis. The main conclusion is that, whereas classical limit analysis applies to materials exhibiting elasticity - in the absence of hardening and within a linearized geometrical framework -, sequential limit analysis, to be applicable, strictly prohibits the presence of elasticity - although it tolerates strain hardening and large displacements and strains. For a given mechanical situation, the relevance of sequential limit analysis therefore essentially depends upon the importance of the elastic-plastic coupling in the specific case considered.

  16. Sequential spatial processes for image analysis

    NARCIS (Netherlands)

    M.N.M. van Lieshout (Marie-Colette); V. Capasso

    2009-01-01

    htmlabstractWe give a brief introduction to sequential spatial processes. We discuss their definition, formulate a Markov property, and indicate why such processes are natural tools in tackling high level vision problems. We focus on the problem of tracking a variable number of moving objects

  17. Sequential spatial processes for image analysis

    NARCIS (Netherlands)

    Lieshout, van M.N.M.; Capasso, V.

    2009-01-01

    We give a brief introduction to sequential spatial processes. We discuss their definition, formulate a Markov property, and indicate why such processes are natural tools in tackling high level vision problems. We focus on the problem of tracking a variable number of moving objects through a video

  18. STABILIZED SEQUENTIAL QUADRATIC PROGRAMMING: A SURVEY

    Directory of Open Access Journals (Sweden)

    Damián Fernández

    2014-12-01

    Full Text Available We review the motivation for, the current state-of-the-art in convergence results, and some open questions concerning the stabilized version of the sequential quadratic programming algorithm for constrained optimization. We also discuss the tools required for its local convergence analysis, globalization challenges, and extentions of the method to the more general variational problems.

  19. Truly costly sequential search and oligopolistic pricing

    NARCIS (Netherlands)

    Janssen, Maarten C W; Moraga-González, José Luis; Wildenbeest, Matthijs R.

    We modify the paper of Stahl (1989) [Stahl, D.O., 1989. Oligopolistic pricing with sequential consumer search. American Economic Review 79, 700-12] by relaxing the assumption that consumers obtain the first price quotation for free. When all price quotations are costly to obtain, the unique

  20. Zips : mining compressing sequential patterns in streams

    NARCIS (Netherlands)

    Hoang, T.L.; Calders, T.G.K.; Yang, J.; Mörchen, F.; Fradkin, D.; Chau, D.H.; Vreeken, J.; Leeuwen, van M.; Faloutsos, C.

    2013-01-01

    We propose a streaming algorithm, based on the minimal description length (MDL) principle, for extracting non-redundant sequential patterns. For static databases, the MDL-based approach that selects patterns based on their capacity to compress data rather than their frequency, was shown to be

  1. How to Read the Tractatus Sequentially

    Directory of Open Access Journals (Sweden)

    Tim Kraft

    2016-11-01

    Full Text Available One of the unconventional features of Wittgenstein’s Tractatus Logico-Philosophicus is its use of an elaborated and detailed numbering system. Recently, Bazzocchi, Hacker und Kuusela have argued that the numbering system means that the Tractatus must be read and interpreted not as a sequentially ordered book, but as a text with a two-dimensional, tree-like structure. Apart from being able to explain how the Tractatus was composed, the tree reading allegedly solves exegetical issues both on the local (e. g. how 4.02 fits into the series of remarks surrounding it and the global level (e. g. relation between ontology and picture theory, solipsism and the eye analogy, resolute and irresolute readings. This paper defends the sequential reading against the tree reading. After presenting the challenges generated by the numbering system and the two accounts as attempts to solve them, it is argued that Wittgenstein’s own explanation of the numbering system, anaphoric references within the Tractatus and the exegetical issues mentioned above do not favour the tree reading, but a version of the sequential reading. This reading maintains that the remarks of the Tractatus form a sequential chain: The role of the numbers is to indicate how remarks on different levels are interconnected to form a concise, surveyable and unified whole.

  2. Adult Word Recognition and Visual Sequential Memory

    Science.gov (United States)

    Holmes, V. M.

    2012-01-01

    Two experiments were conducted investigating the role of visual sequential memory skill in the word recognition efficiency of undergraduate university students. Word recognition was assessed in a lexical decision task using regularly and strangely spelt words, and nonwords that were either standard orthographically legal strings or items made from…

  3. Terminating Sequential Delphi Survey Data Collection

    Science.gov (United States)

    Kalaian, Sema A.; Kasim, Rafa M.

    2012-01-01

    The Delphi survey technique is an iterative mail or electronic (e-mail or web-based) survey method used to obtain agreement or consensus among a group of experts in a specific field on a particular issue through a well-designed and systematic multiple sequential rounds of survey administrations. Each of the multiple rounds of the Delphi survey…

  4. Primary Care Physicians’ Perceptions of the Challenges and Barriers in the Timely Diagnosis, Treatment and Management of Fibromyalgia

    Directory of Open Access Journals (Sweden)

    Nandini Hadker

    2011-01-01

    Full Text Available OBJECTIVES: To describe beliefs and practice patterns of primary care physicians (PCPs providing fibromyalgia (FM care, and to characterize differences between PCPs who report being able to provide timely and beneficial care versus the remaining PCPs.

  5. Dangers and uses of cross-correlation in analyzing time series in perception, performance, movement, and neuroscience: The importance of constructing transfer function autoregressive models.

    Science.gov (United States)

    Dean, Roger T; Dunsmuir, William T M

    2016-06-01

    Many articles on perception, performance, psychophysiology, and neuroscience seek to relate pairs of time series through assessments of their cross-correlations. Most such series are individually autocorrelated: they do not comprise independent values. Given this situation, an unfounded reliance is often placed on cross-correlation as an indicator of relationships (e.g., referent vs. response, leading vs. following). Such cross-correlations can indicate spurious relationships, because of autocorrelation. Given these dangers, we here simulated how and why such spurious conclusions can arise, to provide an approach to resolving them. We show that when multiple pairs of series are aggregated in several different ways for a cross-correlation analysis, problems remain. Finally, even a genuine cross-correlation function does not answer key motivating questions, such as whether there are likely causal relationships between the series. Thus, we illustrate how to obtain a transfer function describing such relationships, informed by any genuine cross-correlations. We illustrate the confounds and the meaningful transfer functions by two concrete examples, one each in perception and performance, together with key elements of the R software code needed. The approach involves autocorrelation functions, the establishment of stationarity, prewhitening, the determination of cross-correlation functions, the assessment of Granger causality, and autoregressive model development. Autocorrelation also limits the interpretability of other measures of possible relationships between pairs of time series, such as mutual information. We emphasize that further complexity may be required as the appropriate analysis is pursued fully, and that causal intervention experiments will likely also be needed.

  6. Sequential bilateral cochlear implantation improves working performance, quality of life, and quality of hearing.

    Science.gov (United States)

    Härkönen, Kati; Kivekäs, Ilkka; Rautiainen, Markus; Kotti, Voitto; Sivonen, Ville; Vasama, Juha-Pekka

    2015-05-01

    This prospective study shows that working performance, quality of life (QoL), and quality of hearing (QoH) are better with two compared with a single cochlear implant (CI). The impact of the second CI on the patient's QoL is as significant as the impact of the first CI. To evaluate the benefits of sequential bilateral cochlear implantation in working, QoL, and QoH. We studied working performance, work-related stress, QoL, and QoH with specific questionnaires in 15 patients with unilateral CI scheduled for sequential CI of another ear. Sound localization performance and speech perception in noise were measured with specific tests. All questionnaires and tests were performed before the second CI surgery and 6 and 12 months after its activation. Bilateral CIs increased patients' working performance and their work-related stress and fatigue decreased. Communication with co-workers was easier and patients were more active in their working environment. Sequential bilateral cochlear implantation improved QoL, QoH, sound localization, and speech perception in noise statistically significantly.

  7. Optimisation of beryllium-7 gamma analysis following BCR sequential extraction

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, A. [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Blake, W.H., E-mail: wblake@plymouth.ac.uk [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Keith-Roach, M.J. [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Kemakta Konsult, Stockholm (Sweden)

    2012-03-30

    Graphical abstract: Showing decrease in analytical uncertainty using the optimal (combined preconcentrated sample extract) method. nv (no value) where extract activities were Sequential extraction with natural {sup 7}Be returns high analytical uncertainties. Black-Right-Pointing-Pointer Preconcentrating extracts from a large sample mass improved analytical uncertainty. Black-Right-Pointing-Pointer This optimised method can be readily employed in studies using low activity samples. - Abstract: The application of cosmogenic {sup 7}Be as a sediment tracer at the catchment-scale requires an understanding of its geochemical associations in soil to underpin the assumption of irreversible adsorption. Sequential extractions offer a readily accessible means of determining the associations of {sup 7}Be with operationally defined soil phases. However, the subdivision of the low activity concentrations of fallout {sup 7}Be in soils into geochemical fractions can introduce high gamma counting uncertainties. Extending analysis time significantly is not always an option for batches of samples, owing to the on-going decay of {sup 7}Be (t{sub 1/2} = 53.3 days). Here, three different methods of preparing and quantifying {sup 7}Be extracted using the optimised BCR three-step scheme have been evaluated and compared with a focus on reducing analytical uncertainties. The optimal method involved carrying out the BCR extraction in triplicate, sub-sampling each set of triplicates for stable Be analysis before combining each set and coprecipitating the {sup 7}Be with metal oxyhydroxides to produce a thin source for gamma analysis. This method was applied to BCR extractions of natural {sup 7}Be in four agricultural soils. The approach gave good counting statistics from a 24 h analysis period ({approx}10% (2

  8. "I Have to Rest All the Time Because You Are Not Allowed to Play": Exploring Children's Perceptions of Autonomy during Sleep-Time in Long Day Care Services

    Science.gov (United States)

    Nothard, Michaela; Irvine, Susan; Theobald, Maryanne; Staton, Sally; Pattinson, Cassandra; Thorpe, Karen

    2015-01-01

    Daytime sleep is a significant part of the daily routine for children attending early childhood education and care (ECEC) services in Australia and many other countries. The practice of sleep-time can account for a substantial portion of the day in ECEC and often involves a mandated sleep/rest period for all children, including older…

  9. Sequential Monte Carlo Instant Radiosity.

    Science.gov (United States)

    Hedman, Peter; Karras, Tero; Lehtinen, Jaakko

    2017-05-01

    Instant Radiosity and its derivatives are interactive methods for efficiently estimating global (indirect) illumination. They represent the last indirect bounce of illumination before the camera as the composite radiance field emitted by a set of virtual point light sources (VPLs). In complex scenes, current algorithms suffer from a difficult combination of two issues: it remains a challenge to distribute VPLs in a manner that simultaneously gives a high-quality indirect illumination solution for each frame, and to do so in a temporally coherent manner. We address both issues by building, and maintaining over time, an adaptive and temporally coherent distribution of VPLs in locations where they bring indirect light to the image. We introduce a novel heuristic sampling method that strives to only move as few of the VPLs between frames as possible. The result is, to the best of our knowledge, the first interactive global illumination algorithm that works in complex, highly-occluded scenes, suffers little from temporal flickering, supports moving cameras and light sources, and is output-sensitive in the sense that it places VPLs in locations that matter most to the final result.

  10. Short-term memory for spatial, sequential and duration information.

    Science.gov (United States)

    Manohar, Sanjay G; Pertzov, Yoni; Husain, Masud

    2017-10-01

    Space and time appear to play key roles in the way that information is organized in short-term memory (STM). Some argue that they are crucial contexts within which other stored features are embedded, allowing binding of information that belongs together within STM. Here we review recent behavioral, neurophysiological and imaging studies that have sought to investigate the nature of spatial, sequential and duration representations in STM, and how these might break down in disease. Findings from these studies point to an important role of the hippocampus and other medial temporal lobe structures in aspects of STM, challenging conventional accounts of involvement of these regions in only long-term memory.

  11. Sequential Detection of Fission Processes for Harbor Defense

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; Walston, S E; Chambers, D H

    2015-02-12

    With the large increase in terrorist activities throughout the world, the timely and accurate detection of special nuclear material (SNM) has become an extremely high priority for many countries concerned with national security. The detection of radionuclide contraband based on their γ-ray emissions has been attacked vigorously with some interesting and feasible results; however, the fission process of SNM has not received as much attention due to its inherent complexity and required predictive nature. In this paper, on-line, sequential Bayesian detection and estimation (parameter) techniques to rapidly and reliably detect unknown fissioning sources with high statistical confidence are developed.

  12. The subtyping of primary aldosteronism by adrenal vein sampling: sequential blood sampling causes factitious lateralization.

    Science.gov (United States)

    Rossitto, Giacomo; Battistel, Michele; Barbiero, Giulio; Bisogni, Valeria; Maiolino, Giuseppe; Diego, Miotto; Seccia, Teresa M; Rossi, Gian Paolo

    2018-02-01

    The pulsatile secretion of adrenocortical hormones and a stress reaction occurring when starting adrenal vein sampling (AVS) can affect the selectivity and also the assessment of lateralization when sequential blood sampling is used. We therefore tested the hypothesis that a simulated sequential blood sampling could decrease the diagnostic accuracy of lateralization index for identification of aldosterone-producing adenoma (APA), as compared with bilaterally simultaneous AVS. In 138 consecutive patients who underwent subtyping of primary aldosteronism, we compared the results obtained simultaneously bilaterally when starting AVS (t-15) and 15 min after (t0), with those gained with a simulated sequential right-to-left AVS technique (R ⇒ L) created by combining hormonal values obtained at t-15 and at t0. The concordance between simultaneously obtained values at t-15 and t0, and between simultaneously obtained values and values gained with a sequential R ⇒ L technique, was also assessed. We found a marked interindividual variability of lateralization index values in the patients with bilaterally selective AVS at both time point. However, overall the lateralization index simultaneously determined at t0 provided a more accurate identification of APA than the simulated sequential lateralization indexR ⇒ L (P = 0.001). Moreover, regardless of which side was sampled first, the sequential AVS technique induced a sequence-dependent overestimation of lateralization index. While in APA patients the concordance between simultaneous AVS at t0 and t-15 and between simultaneous t0 and sequential technique was moderate-to-good (K = 0.55 and 0.66, respectively), in non-APA patients, it was poor (K = 0.12 and 0.13, respectively). Sequential AVS generates factitious between-sides gradients, which lower its diagnostic accuracy, likely because of the stress reaction arising upon starting AVS.

  13. Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems.

    Science.gov (United States)

    Harari, Colin M; Magagna, Michelle; Bedoya, Mariajose; Lee, Fred T; Lubner, Meghan G; Hinshaw, J Louis; Ziemlewicz, Timothy; Brace, Christopher L

    2016-01-01

    To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue. All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type. On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery. © RSNA, 2015.

  14. Sequential vs simultaneous encoding of spatial information: a comparison between the blind and the sighted.

    Science.gov (United States)

    Ruotolo, Francesco; Ruggiero, Gennaro; Vinciguerra, Michela; Iachini, Tina

    2012-02-01

    The aim of this research is to assess whether the crucial factor in determining the characteristics of blind people's spatial mental images is concerned with the visual impairment per se or the processing style that the dominant perceptual modalities used to acquire spatial information impose, i.e. simultaneous (vision) vs sequential (kinaesthesis). Participants were asked to learn six positions in a large parking area via movement alone (congenitally blind, adventitiously blind, blindfolded sighted) or with vision plus movement (simultaneous sighted, sequential sighted), and then to mentally scan between positions in the path. The crucial manipulation concerned the sequential sighted group. Their visual exploration was made sequential by putting visual obstacles within the pathway in such a way that they could not see simultaneously the positions along the pathway. The results revealed a significant time/distance linear relation in all tested groups. However, the linear component was lower in sequential sighted and blind participants, especially congenital. Sequential sighted and congenitally blind participants showed an almost overlapping performance. Differences between groups became evident when mentally scanning farther distances (more than 5m). This threshold effect could be revealing of processing limitations due to the need of integrating and updating spatial information. Overall, the results suggest that the characteristics of the processing style rather than the visual impairment per se affect blind people's spatial mental images. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. The desire to hasten death: Using Grounded Theory for a better understanding "When perception of time tends to be a slippery slope".

    Science.gov (United States)

    Pestinger, Martina; Stiel, Stephanie; Elsner, Frank; Widdershoven, Guy; Voltz, Raymond; Nauck, Friedemann; Radbruch, Lukas

    2015-09-01

    Some patients with advanced and progressive diseases express a desire to hasten death. This study evaluated the motivations of patients expressing such a desire in a country with prohibitive legislation on euthanasia and physician-assisted suicide. A modified form of Grounded Theory was used. Patients from the departments of palliative medicine in three hospitals in Germany were recruited when they had made a statement or request to hasten death. Participants were interviewed face to face. Recruitment was stopped with 12 participants because of data saturation. Thematic analysis revealed three main motivational themes: self-determination, agony, and time. Expectations toward health professionals, attitudes toward death, and secureness related to the end of life were additional main themes emerging from the analysis. The desire to hasten death may be used as an extreme coping strategy to maintain control against anticipated agony. Patients expected health professionals to listen to and respect their experiences. Emerging hypotheses included the following: (a) patients try to balance life time and anticipated agony, and the perception of time is distressing in this balancing act; (b) anticipated images of agony and suffering in the dying process occur frequently and are experienced by patients as intrusive; (c) patients expressing a desire to hasten death are in need of more information about the dying process; and (d) patients wanted their caregivers to listen to and respect their wish to hasten death, and they did not expect the caregivers to understand this as an order to actually hasten their death. © The Author(s) 2015.

  16. Impact of Diagrams on Recalling Sequential Elements in Expository Texts.

    Science.gov (United States)

    Guri-Rozenblit, Sarah

    1988-01-01

    Examines the instructional effectiveness of abstract diagrams on recall of sequential relations in social science textbooks. Concludes that diagrams assist significantly the recall of sequential relations in a text and decrease significantly the rate of order mistakes. (RS)

  17. Changes in perception-action tuning over long time scales: How children and adults perceive and act on dynamic affordances when crossing roads.

    Science.gov (United States)

    O'Neal, Elizabeth E; Jiang, Yuanyuan; Franzen, Lucas J; Rahimian, Pooya; Yon, Junghum Paul; Kearney, Joseph K; Plumert, Jodie M

    2018-01-01

    This investigation examined developmental change in how children perceive and act on dynamic affordances when crossing roads on foot. Six- to 14-year-olds and adults crossed roads with continuous cross-traffic in a large-screen, immersive pedestrian simulator. We observed change both in children's gap choices and in their ability to precisely synchronize their movement with the opening of a gap. Younger children were less discriminating than older children and adults, choosing fewer large gaps and more small gaps. Interestingly, 12-year-olds' gap choices were significantly more conservative than those of 6-, 8-, 10-, and 14-year-olds, and adults. Timing of entry behind the lead vehicle in the gap (a key measure of movement coordination) improved steadily with development, reaching adultlike levels by age 14. Coupled with their poorer timing of entry, 6-, 8-, and 10-year-olds' gap choices resulted in significantly less time to spare and more collisions than 14-year-olds and adults. Time to spare did not differ between 12-year-olds, 14-year-olds, and adults, indicating that 12-year-olds' more conservative gap choices compensated for their poorer timing of entry. The findings show that children's ability to perceive and act on dynamic affordances undergoes a prolonged period of development, and that older children appear to compensate for their poorer movement timing skills by adjusting their gap decisions to match their crossing actions. Implications for the development of perception-action tuning and road-crossing skills are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  18. Health care and social service professionals' perceptions of a home-visit program for young, first-time mothers.

    Science.gov (United States)

    Li, S A; Jack, S M; Gonzalez, A; Duku, E; MacMillan, H L

    2015-01-01

    Little is known about health care and social service professionals' perspective on the acceptability of long-term home-visit programs serving low-income, first-time mothers. This study describes the experiences and perspectives of these community care providers involved with program referrals or service delivery to mothers who participated in the Nurse-Family Partnership (NFP), a targeted nurse home-visit program. The study included two phases. Phase I was a secondary qualitative data analysis used to analyze a purposeful sample of 24 individual interviews of community care providers. This was part of a larger case study examining adaptations required to increase acceptability of the NFP in Hamilton, Ontario, Canada. In Phase II (n = 4), themes identified from Phase I were further explored through individual, semi-structured interviews with community health care and social service providers, giving qualitative description. Overall, the NFP was viewed as addressing an important service gap for first-time mothers. Providers suggested that frequent communication between the NFP and community agencies serving these mothers could help improve the referral process, avoid service duplication, and streamline the flow of service access. The findings can help determine key components required to enhance the success of integrating a home-visit program into an existing network of community services. The function of home-visit programs should not be viewed in isolation. Rather, their potential can be maximized when they collaborate and share information with other agencies to provide better services for first-time mothers.

  19. What is the time scale of random sequential adsorption?

    OpenAIRE

    Erban, Radek; Chapman, S. Jonathan

    2006-01-01

    A simple multiscale approach to the diffusion-driven adsorption from a solution to a solid surface is presented. The model combines two important features of the adsorption process: (i) the kinetics of the chemical reaction between adsorbing molecules and the surface; and (ii) geometrical constraints on the surface made by molecules which are already adsorbed. The process (i) is modelled in a diffusion-driven context, i.e. the conditional probability of adsorbing a molecule provided that the ...

  20. Accepting telemedicine in a circulatory medicine ward in major hospitals in South Korea: patients' and health professionals' perception of real-time electrocardiogram monitoring.

    Science.gov (United States)

    Lee, Seo-Joon; Jung, Tae-Young; Lee, Tae-Ro; Han, Jae-Hoon

    2018-04-20

    South Korean government is currently in progress of expanding the coverage of telemedicine projects as part of an attempt to vitalize service industry, but is facing fierce opposition from KMA. Practice of telemedicine requires sufficient discussions among related parties. Although the participation of medical specialists is important, agreement from the public is essential. Three main tertiary care centers in Seoul were selected for data collection. A total of 224 patients (patients n = 180, patient guardian n = 44) and medical professionals (n = 41) were selected using simple random sampling. Mixed method of quantitative survey and qualitative semi-interview was used. This study analyzed patients' and medical professionals' perception about the application of telemedicine in cardiology ward in tertiary care centers to provide baseline data when developing and applying telemedicine services. Results implied high need for encouraging telemedicine projects in order to appeal needs among population by providing experience (p < 0.001) and knowledge (p < 0.001). Other results showed that the need for electrocardiography monitoring was high among not only in remote areas but also in areas close to the capital. 64.52% of all participants thought that telemedicine was needed, and 73.21% of participants were willing to use telemedicine service if provided. Semi-interviews revealed that participants expected more cost and time saving services through remote treatment, by not having to visit long distance hospitals frequently. Research results oppose Korean Medical Association's opinion that the population is against enforcing telemedicine related laws. The findings in this study reflect an up-to-date perception of telemedicine among patients and medical professionals in a tertiary care centers' cardiology ward. Moreover, the study provides a baseline that is needed in order to overcome past failures and to successfully implement telemedicine in South

  1. Documentscape: Intertextuality, Sequentiality & Autonomy at Work

    DEFF Research Database (Denmark)

    Christensen, Lars Rune; Bjørn, Pernille

    2014-01-01

    On the basis of an ethnographic field study, this article introduces the concept of documentscape to the analysis of document-centric work practices. The concept of documentscape refers to the entire ensemble of documents in their mutual intertextual interlocking. Providing empirical data from...... a global software development case, we show how hierarchical structures and sequentiality across the interlocked documents are critical to how actors make sense of the work of others and what to do next in a geographically distributed setting. Furthermore, we found that while each document is created...... as part of a quasi-sequential order, this characteristic does not make the document, as a single entity, into a stable object. Instead, we found that the documents were malleable and dynamic while suspended in intertextual structures. Our concept of documentscape points to how the hierarchical structure...

  2. A minimax procedure in the context of sequential mastery testing

    NARCIS (Netherlands)

    Vos, Hendrik J.

    1999-01-01

    The purpose of this paper is to derive optimal rules for sequential mastery tests. In a sequential mastery test, the decision is to classify a subject as a master or a nonmaster, or to continue sampling and administering another random test item. The framework of minimax sequential decision theory

  3. Applying the minimax principle to sequential mastery testing

    NARCIS (Netherlands)

    Vos, Hendrik J.

    2002-01-01

    The purpose of this paper is to derive optimal rules for sequential mastery tests. In a sequential mastery test, the decision is to classify a subject as a master, a nonmaster, or to continue sampling and administering another random item. The framework of minimax sequential decision theory (minimum

  4. Optimal Sequential Rules for Computer-Based Instruction.

    Science.gov (United States)

    Vos, Hans J.

    1998-01-01

    Formulates sequential rules for adapting the appropriate amount of instruction to learning needs in the context of computer-based instruction. Topics include Bayesian decision theory, threshold and linear-utility structure, psychometric model, optimal sequential number of test questions, and an empirical example of sequential instructional…

  5. On Locally Most Powerful Sequential Rank Tests

    Czech Academy of Sciences Publication Activity Database

    Kalina, Jan

    2017-01-01

    Roč. 36, č. 1 (2017), s. 111-125 ISSN 0747-4946 R&D Projects: GA ČR GA17-07384S Grant - others:Nadační fond na podporu vědy(CZ) Neuron Institutional support: RVO:67985807 Keywords : nonparametric test s * sequential ranks * stopping variable Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.339, year: 2016

  6. Sequential pattern recognition by maximum conditional informativity

    Czech Academy of Sciences Publication Activity Database

    Grim, Jiří

    2014-01-01

    Roč. 45, č. 1 (2014), s. 39-45 ISSN 0167-8655 R&D Projects: GA ČR(CZ) GA14-02652S; GA ČR(CZ) GA14-10911S Keywords : Multivariate statistics * Statistical pattern recognition * Sequential decision making * Product mixtures * EM algorithm * Shannon information Subject RIV: IN - Informatics, Computer Sci ence Impact factor: 1.551, year: 2014 http://library.utia.cas.cz/separaty/2014/RO/grim-0428565.pdf

  7. Heat accumulation during sequential cortical bone drilling.

    Science.gov (United States)

    Palmisano, Andrew C; Tai, Bruce L; Belmont, Barry; Irwin, Todd A; Shih, Albert; Holmes, James R

    2016-03-01

    Significant research exists regarding heat production during single-hole bone drilling. No published data exist regarding repetitive sequential drilling. This study elucidates the phenomenon of heat accumulation for sequential drilling with both Kirschner wires (K wires) and standard two-flute twist drills. It was hypothesized that cumulative heat would result in a higher temperature with each subsequent drill pass. Nine holes in a 3 × 3 array were drilled sequentially on moistened cadaveric tibia bone kept at body temperature (about 37 °C). Four thermocouples were placed at the center of four adjacent holes and 2 mm below the surface. A battery-driven hand drill guided by a servo-controlled motion system was used. Six samples were drilled with each tool (2.0 mm K wire and 2.0 and 2.5 mm standard drills). K wire drilling increased temperature from 5 °C at the first hole to 20 °C at holes 6 through 9. A similar trend was found in standard drills with less significant increments. The maximum temperatures of both tools increased from drill sizes was found to be insignificant (P > 0.05). In conclusion, heat accumulated during sequential drilling, with size difference being insignificant. K wire produced more heat than its twist-drill counterparts. This study has demonstrated the heat accumulation phenomenon and its significant effect on temperature. Maximizing the drilling field and reducing the number of drill passes may decrease bone injury. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. Sequential test procedures for inventory differences

    International Nuclear Information System (INIS)

    Goldman, A.S.; Kern, E.A.; Emeigh, C.W.

    1985-01-01

    By means of a simulation study, we investigated the appropriateness of Page's and power-one sequential tests on sequences of inventory differences obtained from an example materials control unit, a sub-area of a hypothetical UF 6 -to-U 3 O 8 conversion process. The study examined detection probability and run length curves obtained from different loss scenarios. 12 refs., 10 figs., 2 tabs

  9. Sequential neural models with stochastic layers

    DEFF Research Database (Denmark)

    Fraccaro, Marco; Sønderby, Søren Kaae; Paquet, Ulrich

    2016-01-01

    How can we efficiently propagate uncertainty in a latent state representation with recurrent neural networks? This paper introduces stochastic recurrent neural networks which glue a deterministic recurrent neural network and a state space model together to form a stochastic and sequential neural...... generative model. The clear separation of deterministic and stochastic layers allows a structured variational inference network to track the factorization of the model's posterior distribution. By retaining both the nonlinear recursive structure of a recurrent neural network and averaging over...

  10. Perception of Not Having Enough Milk and Actual Milk Production of First-Time Breastfeeding Mothers: Is There a Difference?

    Science.gov (United States)

    Galipeau, Roseline; Dumas, Louise; Lepage, Mario

    2017-05-01

    This study aimed to determine the relationship between perceived insufficient milk supply (PIMS) and actual insufficient milk supply (AIMS) and the relative contributions of physiological and psychosocial variables on both PIMS and AIMS of first-time breastfeeding mothers. Data were collected among 123 breastfeeding mothers at a Canadian, French-speaking maternal care hospital. Birth events, breastfeeding practices, infant and maternal capacities, and PIMS and AIMS were collected at 48 hours after birth, postnatal weeks 2 and 6. No significant relationship was found between PIMS and AIMS. Maternal breastfeeding self-efficacy and number of feeds were related to PIMS at week 2, and skin-to-skin contact at birth and number of feeds were related to AIMS as measured by 24-hour milk production at week 2. Maternal breastfeeding self-efficacy impacts PIMS. Interventions should be directed to increase maternal confidence in breastfeeding, which in turn influences breastfeeding duration.

  11. Perceptions of Employment and Use of Part-Time Faculty among Chief Instructional Officers at Southern Association of Colleges and Schools-Accredited Public Associate's Colleges

    Science.gov (United States)

    Speer, Charlotte Nix

    2013-01-01

    Based on Yackee's (2000) study of the perceptions of chief instructional officers (CIOs) at community colleges accredited by North Central Association of Colleges and Schools (NCA), this study identified, described, and compared the perceptions of CIOs at institutions accredited by Southern Association of Colleges and Schools Commission on…

  12. Simultaneous Versus Sequential Side-by-Side Bilateral Metal Stent Placement for Malignant Hilar Biliary Obstructions.

    Science.gov (United States)

    Inoue, Tadahisa; Ishii, Norimitsu; Kobayashi, Yuji; Kitano, Rena; Sakamoto, Kazumasa; Ohashi, Tomohiko; Nakade, Yukiomi; Sumida, Yoshio; Ito, Kiyoaki; Nakao, Haruhisa; Yoneda, Masashi

    2017-09-01

    Endoscopic bilateral self-expandable metallic stent (SEMS) placement for malignant hilar biliary obstructions (MHBOs) is technically demanding, and a second SEMS insertion is particularly challenging. A simultaneous side-by-side (SBS) placement technique using a thinner delivery system may mitigate these issues. We aimed to examine the feasibility and efficacy of simultaneous SBS SEMS placement for treating MHBOs using a novel SEMS that has a 5.7-Fr ultra-thin delivery system. Thirty-four patients with MHBOs underwent SBS SEMS placement between 2010 and 2016. We divided the patient cohort into those who underwent sequential (conventional) SBS placement between 2010 and 2014 (sequential group) and those who underwent simultaneous SBS placement between 2015 and 2016 (simultaneous group), and compared the groups with respect to the clinical outcomes. The technical success rates were 71% (12/17) and 100% (17/17) in the sequential and simultaneous groups, respectively, a difference that was significant (P = .045). The median procedure time was significantly shorter in the simultaneous group (22 min) than in the sequential group (52 min) (P = .017). There were no significant group differences in the time to recurrent biliary obstruction (sequential group: 113 days; simultaneous group: 140 days) or other adverse event rates (sequential group: 12%; simultaneous group: 12%). Simultaneous SBS placement using the novel 5.7-Fr SEMS delivery system may be more straightforward and have a higher success rate compared to that with sequential SBS placement. This new method may be useful for bilateral stenting to treat MHBOs.

  13. Mining Sequential Update Summarization with Hierarchical Text Analysis

    Directory of Open Access Journals (Sweden)

    Chunyun Zhang

    2016-01-01

    Full Text Available The outbreak of unexpected news events such as large human accident or natural disaster brings about a new information access problem where traditional approaches fail. Mostly, news of these events shows characteristics that are early sparse and later redundant. Hence, it is very important to get updates and provide individuals with timely and important information of these incidents during their development, especially when being applied in wireless and mobile Internet of Things (IoT. In this paper, we define the problem of sequential update summarization extraction and present a new hierarchical update mining system which can broadcast with useful, new, and timely sentence-length updates about a developing event. The new system proposes a novel method, which incorporates techniques from topic-level and sentence-level summarization. To evaluate the performance of the proposed system, we apply it to the task of sequential update summarization of temporal summarization (TS track at Text Retrieval Conference (TREC 2013 to compute four measurements of the update mining system: the expected gain, expected latency gain, comprehensiveness, and latency comprehensiveness. Experimental results show that our proposed method has good performance.

  14. Young Athletes' Perceptions of Coach Behaviors and Their Implications on Their Well- and Ill-Being Over Time.

    Science.gov (United States)

    González, Lorena; García-Merita, Marisa; Castillo, Isabel; Balaguer, Isabel

    2016-04-01

    Grounded on basic psychological needs theory the purpose of this study was twofold: (a) to test the mediational role of basic psychological needs (satisfaction and thwarting), and (b) to test the model invariance over 2 consecutive seasons. Three hundred sixty young male athletes completed a questionnaire package tapping the variables of interest at 4 time points during 2 consecutive seasons. Results of the path analyses revealed that in both seasons, changes in perceived coach autonomy supportive style positively predicted changes in needs satisfaction which, in turn, positively predicted changes in self-esteem; changes in perceived coach autonomy supportive and controlling style negatively and positively, respectively, predicted changes in needs thwarting which, in turn, positively predicted changes in burnout and negatively in self-esteem. Only in the first season, changes in needs satisfaction emerged as a negative predictor of changes in burnout. The mediational role of basic psychological needs and the invariance of the aforementioned relationships over the 2 seasons were supported. Results emphasize the importance of having coaches promoting autonomy supportive atmospheres and avoiding controlling styles to facilitate athletes' well-being and to prevent their ill-being.

  15. Group sequential designs for stepped-wedge cluster randomised trials.

    Science.gov (United States)

    Grayling, Michael J; Wason, James Ms; Mander, Adrian P

    2017-10-01

    The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency gains and ethical benefits. We address this by discussing how established group sequential methodology can be adapted for stepped-wedge designs. Utilising the error spending approach to group sequential trial design, we detail the assumptions required for the determination of stepped-wedge cluster randomised trials with interim analyses. We consider early stopping for efficacy, futility, or efficacy and futility. We describe first how this can be done for any specified linear mixed model for data analysis. We then focus on one particular commonly utilised model and, using a recently completed stepped-wedge cluster randomised trial, compare the performance of several designs with interim analyses to the classical stepped-wedge design. Finally, the performance of a quantile substitution procedure for dealing with the case of unknown variance is explored. We demonstrate that the incorporation of early stopping in stepped-wedge cluster randomised trial designs could reduce the expected sample size under the null and alternative hypotheses by up to 31% and 22%, respectively, with no cost to the trial's type-I and type-II error rates. The use of restricted error maximum likelihood estimation was found to be more important than quantile substitution for controlling the type-I error rate. The addition of interim analyses into stepped-wedge cluster randomised trials could help guard against time-consuming trials conducted on poor performing treatments and also help expedite the implementation of efficacious treatments. In future, trialists should consider incorporating early stopping of some kind into

  16. Sequential decoding of intramuscular EMG signals via estimation of a Markov model.

    Science.gov (United States)

    Monsifrot, Jonathan; Le Carpentier, Eric; Aoustin, Yannick; Farina, Dario

    2014-09-01

    This paper addresses the sequential decoding of intramuscular single-channel electromyographic (EMG) signals to extract the activity of individual motor neurons. A hidden Markov model is derived from the physiological generation of the EMG signal. The EMG signal is described as a sum of several action potentials (wavelet) trains, embedded in noise. For each train, the time interval between wavelets is modeled by a process that parameters are linked to the muscular activity. The parameters of this process are estimated sequentially by a Bayes filter, along with the firing instants. The method was tested on some simulated signals and an experimental one, from which the rates of detection and classification of action potentials were above 95% with respect to the reference decomposition. The method works sequentially in time, and is the first to address the problem of intramuscular EMG decomposition online. It has potential applications for man-machine interfacing based on motor neuron activities.

  17. Heuristic and optimal policy computations in the human brain during sequential decision-making.

    Science.gov (United States)

    Korn, Christoph W; Bach, Dominik R

    2018-01-23

    Optimal decisions across extended time horizons require value calculations over multiple probabilistic future states. Humans may circumvent such complex computations by resorting to easy-to-compute heuristics that approximate optimal solutions. To probe the potential interplay between heuristic and optimal computations, we develop a novel sequential decision-making task, framed as virtual foraging in which participants have to avoid virtual starvation. Rewards depend only on final outcomes over five-trial blocks, necessitating planning over five sequential decisions and probabilistic outcomes. Here, we report model comparisons demonstrating that participants primarily rely on the best available heuristic but also use the normatively optimal policy. FMRI signals in medial prefrontal cortex (MPFC) relate to heuristic and optimal policies and associated choice uncertainties. Crucially, reaction times and dorsal MPFC activity scale with discrepancies between heuristic and optimal policies. Thus, sequential decision-making in humans may emerge from integration between heuristic and optimal policies, implemented by controllers in MPFC.

  18. Mobility of radionuclides based on sequential extraction of soils

    International Nuclear Information System (INIS)

    Salbu, B.; Oughton, D.H.; Lien, H.N.; Oestby, G.; Strand, P.

    1992-01-01

    Since 1989, core samples of soil and vegetation from semi-natural pastures have been collected at selected sites in Norway during the growing season. The activity concentrations in soil and vegetation as well as transfer coefficients vary significantly between regions, within regions and even within sampling plot areas. In order to differentiate between mobil and inert fractions of radioactive and stable isotopes of Cs and Sr in soils, samples were extracted sequentially using agents with increasing dissolution power. The reproducibility of the sequential extraction technique is good and the data obtained seems most informative. As the distribution pattern for radioactive and stable isotopes of Cs and Sr are similar, a high degree of isotopic exchange is indicated. Based on easily leachable fractions, mobility factors are calculated. In general the mobility of 90 Sr is higher than for 137 Cs. Mobility factors are not significantly influenced by seasonal variations, but a decrease in the mobile fraction in soil with time is indicated. Mobility factors should be considered useful for modelling purposes. (au)

  19. Evaluation of sequential aerated treatment of wastewater from hardboard mill

    Directory of Open Access Journals (Sweden)

    S. Videla

    1998-01-01

    Full Text Available Wastewater from a hardboard mill characterized by a high organic content (15-30 g/L COD was studied in a bench scale sequential aerated system in order to define a start up strategy. Inlet COD concentration varied from 0.5 to 25 g/L and the hydraulic retention time was maintained at 5 days. The sequential system proposed could reduce BOD, COD, TSS and phenol over 90% except when the inlet COD concentration was lower than 25 g/L.Água residual proveniente de uma indústria de tabuleiro de fibra dura caracterizada por ter um elevado conteúdo orgânico (15-30 g/L DQO foi estudada utilizando um sistema arejado seqüêncial de forma a definir uma estratégia de start up. A concentração de DQO na entrada do sistema variou na faixa de 0,5-25 g/L e o tempo de residência hidráulico foi mantido em 5 dias. O sistema seqüêncial proposto reduziu DBO, DQO, SST e fenol sobre 90% quando a concentração de DQO na entrada foi menor a 25 g/L.

  20. On Locally Most Powerful Sequential Rank Tests

    Czech Academy of Sciences Publication Activity Database

    Kalina, Jan

    2017-01-01

    Roč. 36, č. 1 (2017), s. 111-125 ISSN 0747-4946 R&D Projects: GA ČR GA17-07384S Grant - others:Nadační fond na podporu vědy(CZ) Neuron Institutional support: RVO:67985556 Keywords : nonparametric test s * sequential ranks * stopping variable Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.339, year: 2016 http://library.utia.cas.cz/separaty/2017/SI/kalina-0474065.pdf