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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Baseball’s Sight-Audition Farness Effect (Safe) When Umpiring Baserunners: Competing Visual and Auditory Cues

January 2017 (has links)
abstract: In baseball, the difference between a win and loss can come down to a single call, such as when an umpire judges force outs at first base by typically comparing competing auditory and visual inputs of the ball-mitt sound and the foot-on-base sight. Yet, because the speed of sound in air only travels about 1100 feet per second, fans observing from several hundred feet away will receive auditory cues that are delayed a significant portion of a second, and thus conceivably could systematically differ in judgments compared to the nearby umpire. The current research examines two questions. 1. How reliably and with what biases do observers judge the order of visual versus auditory events? 2. Do observers making such order judgments from far away systematically compensate for delays due to the slow speed of sound? It is hypothesized that if any temporal bias occurs it is in the direction consistent with observers not accounting for the sound delay, such that increasing viewing distance will increase the bias to assume the sound occurred later. It was found that nearby observers are relatively accurate at judging if a sound occurred before or after a simple visual event (a flash), but exhibit a systematic bias to favor visual stimuli occurring first (by about 30 msec). In contrast, distant observers did not compensate for the delay of the speed of sound such that they systematically favored the visual cue occurring earlier as a function of viewing distance. When observers judged simple visual stimuli in motion relative to the same sound burst, the distance effect occurred as a function of the visual clarity of the ball arriving. In the baseball setting, using a large screen projection of baserunner, a diminished distance effect occurred due to the additional visual cues. In summary, observers generally do not account for the delay of sound due to distance. / Dissertation/Thesis / Masters Thesis Psychology 2017
222

How emotional videos influence motor timing and retrospective duration judgments.

Zhang, Anran January 2018 (has links)
An emotionally involved event may subsequently appear shorter than an event of relative indifference for people. How are time-related behaviors influenced while people are emotionally affected? The purpose of this study was to test if ongoing estimates and retrospective reports of duration are similarly affected by emotional states. To test, 30 s emotional video clips were rated for Valence and Arousal by six participants. The videos were then used in a timing experiment where a new set of participants (twenty-five persons) carried out a repetitive motor timing paradigm while watching the videos and subsequently reported the perceived duration of the clip. In each of ten trials, participants first synchronized to a 700 ms isochronous interval with their index finger, and then continued unsupported as five different video clips were played in sequence, with each clip lasting 30s. At the end of each trial, participants reported their retrospective duration judgment of every video clip, and rated every video chip for Valence and Arousal. Emotion ratings suggested that the videos affected the subjects’ emotional states. Repetitive motor timing was not reliably affected by emotional states. Instead, retrospective reports of durations were affected by emotional states such that the durations estimated under high arousal conditions were significantly longer than those under low arousal conditions. The difference in results between repetitive motor timing and retrospective reports may be accounted for by the interval of 700 ms being too short to be cognitive-related.
223

A coordenação bimanual em função do foco atencional /

Alleoni, Bruno Nascimento. January 2007 (has links)
Orientador: Ana Maria Pellegrini / Banca: Sérgio Tosi Rodrigues / Banca: Cynthia Yukiko Hiraga / Resumo: A coordenação bimanual é um comportamento manifestado diariamente pelas pessoas na execução de tarefas do dia-a-dia. Controlar as duas mãos para varrer a casa, soltar pipa, costurar ou tocar piano são situações rotineiras que podem ser melhoradas e desempenhadas com precisão como resultado da prática. As tarefas unimanuais e as tarefas bimanuais que devem ser lideradas por uma das mãos, geralmente, são executadas apenas com a mão preferida, a mão direita para o maior número de pessoas. As ferramentas utilizadas nas tarefas do dia-a-dia são fabricadas para a mão direita e como conseqüência a diferença no desempenho é menor entre as mãos de pessoas com preferência manual esquerda. Manter um ritmo qualquer ou acertar alvos são tarefas que requeiram integridade de estruturas orgânicas, como por exemplo, os membros superiores e os sistemas visual e auditivo. O direcionamento da atenção visual pode ser muito importante na captura da informação para tocar alvos no plano horizontal, principalmente se as características espaciais e temporais das tarefas das duas mãos são diferentes. Contudo, as duas mãos estão separadas fisicamente e no desempenho em uma tarefa que requeira deslocamentos diferentes para as duas mãos o executante deve identificar a informação de uma das mãos para a execução precisa. O objetivo deste estudo foi verificar o efeito do direcionamento da atenção visual a uma das mãos no desempenho de uma tarefa bimanual com diferentes níveis de complexidade, em função da preferência manual. Pessoas com preferência manual direita e esquerda executaram uma tarefa de coordenação bimanual com deslocamentos dos membros superiores para o toque em um ou mais alvos que estavam igualmente distantes no plano horizontal e em intervalos temporais iguais ou diferentes. O direcionamento da atenção visual foi manipulado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Bimanual coordination is a behavior showed by people during the performance of many daily tasks. Actions that require the control of the hands as to sweep the room, to free pipe, to sew or to play piano are very common actions that can be improved and performed with accuracy as a result of practice. The unimanual tasks and the bimanual tasks that must be led by one of the hands, in general, are performed by the preferred hand, the right hand for a large number of individuals. Tools used in daily tasks are tailored for right hand and as a consequence the difference in performance between hands is smaller for those left-handed. To keep moving in a rhythm or to reach targets are tasks that require a full functioning of organic structures as the upper limbs or visual and auditory systems. The direction of visual attention can be very important in capturing relevant information for touching targets in the horizontal plane mainly if the characteristics of tasks of the two hands are different. However, the hands are physically apart and in the performance of a task that requires different displacements for the two hands the performer must pick up information from one of the hands for performance accuracy. The objective of the present study was to verify the effect of directing visual attention to one of the hands in the performance of bimanual tasks with different levels of complexity as a function of hand preference. Right- and left-handers performed a bimanual coordination task with displacement of the upper arms to reach one or more targets that were equally distant in the horizontal plane and in equal or different temporal intervals. The direction of visual attention was manipulated in three experimental conditions, in a condition directed to the right hand, in another to the left hand and in a third condition of free choice of the performer. The variables selected... (Complete abstract click electronic access below) / Mestre
224

Do Hedge Fund Managers Possess Timing and Selectivity Skill? Evidence from Stock Holdings

January 2013 (has links)
abstract: I study the performance of hedge fund managers, using quarterly stock holdings from 1995 to 2010. I use the holdings-based measure built on Ferson and Mo (2012) to decompose a manager's overall performance into stock selection and three components of timing ability: market return, volatility, and liquidity. At the aggregate level, I find that hedge fund managers have stock picking skills but no timing skills, and overall I do not find strong evidence to support their superiority. I show that the lack of abilities is driven by the large fluctuations of timing performance with market conditions. I find that conditioning information, equity capital constraints, and priority in stocks to liquidate can partly explain the weak evidence. At the individual fund level, bootstrap analysis results suggest that even top managers' abilities cannot be separated from luck. Also, I find that hedge fund managers exhibit short-horizon persistence in selectivity skill. / Dissertation/Thesis / Ph.D. Business Administration 2013
225

The Need for Speed : Delays in Deployment of UN Peacekeepers and Mission Effectiveness

Jansson, Gunilla January 2018 (has links)
No description available.
226

Measuring and Analysing Execution Time in an Automotive Real-Time Application / Exekveringstid i ett Realtidssystem för Fordon

Liljeroth, Henrik January 2009 (has links)
Autoliv has developed the Night Vision system, which is a safety system for use incars to improve the driver’s situational awareness during night conditions. It is areal-time system that is able to detect pedestrians in the traffic environment andissue warnings when there is a risk of collision. The timing behaviour of programsrunning on real-time systems is vital information when developing and optimisingboth hardware and software. As a part of further developing their Night Visionsystem, Autoliv wanted to examine detailed timing behaviour of a specific part ofthe Night Vision algorithm, namely the Tracking module, which tracks detectedpedestrians. Parallel to this, they also wanted a reliable method to obtain timingdata that would work for other parts of that system as well, or even other applications. A preliminary study was conducted in order to determine the most suitable methodof obtaining the timing data desired. This resulted in a measurement-based approachusing software profiling, in which the Tracking module was measured usingvarious input data. The measurements were performed on simulated hardwareusing both a cycle accurate simulator and measurement tools from the systemCPU manufacturer, as well as tools implemented specifically to handle input andoutput data. The measurements resulted in large amounts of data used to compile performancestatistics. Using different scenarios in the input data, we were able to obtain timingcharacteristics for several typical situations the system may encounter duringoperation. By manipulating the input data we were also able to observe generalbehaviour and achieve artificially high execution times, which serves as indicationson how the system responds to irregular and unexpected input data. The method used for collecting timing information was well suited for this particularproject. It provided the possibility to analyse behavior in a better waythan other, more theoretical, approaches would have. The method is also easilyadaptable to other parts of the Night Vision system, or other systems, with onlyminor adjustments to measurement environment and tools.
227

TIME PREDICTABILITY OF GPU KERNEL ON AN HSA COMPLIANT PLATFORM

Tsog, Nandinbaatar, Larsson, Marcus January 2016 (has links)
During recent years, the importance of utilizing more computational power in smaller computersystems has increased. The utilization of more computational power in smaller packages, the abil-ity to combine more than one type of processor unit has become more popular in the industry. By combining, one achieves more power efficiency as well as gain more computational power insmaller area. However, heterogeneous programming has proved to be difficult, and that makes soft-ware developers diverge from learning heterogeneous programming languages. This has motivatedHSA foundation to develop a new hardware architecture, called Heterogeneous System Architecture(HSA). This architecture brings features that make the process of heterogeneous programming de-velopment more accessible, efficient, and easier to the software developers. The purpose of thisthesis is to investigate this new architecture, to learn and observe the timing characteristics of atask running a parallel region (a kernel) on a GPU in an HSA compliant system. With an objectiveto gain more knowledge, four test cases have been developed to collect time data and to analyzethe time of the code executed on the GPU. These are: comparison between CPU and GPU, tim-ing predictability of parallel periodic tasks, schedulability in HSA, and memory copy. Based onthe results of the analysis, it has been concluded that the HSA has potential to be very attractivefor developing heterogeneous programs due to its more streamlined infrastructure. It is easier toadapt, requires less knowledge regarding the underlying hardware, and the software developers canuse their preferred programming languages, instead of learning new programming framework, suchas OpenCL. However, since the architecture is new, there are bugs and HSA features that are yetto be incorporated into the drivers. Performance wise, HSA is faster compared to legacy methods,but lacks in providing consistent time predictability, which is important for real-time systems.
228

Ice, ice, baby? : a sociological exploration of social egg freezing

Baldwin, Kylie January 2016 (has links)
Social egg freezing is a fertility preservation strategy which enables women to preserve a number of healthy unfertilised eggs for potential future use when faced with the threat of age-related fertility decline. The overall aim of this thesis was to explore how women understand, construct and experience social egg freezing in the context of debates surrounding reproductive ‘choice’ and ‘delayed motherhood’. The study sought to provide insights into how women perceive the risks and benefits of social egg freezing, how it relates to their discourses of parenthood and their future reproductive intentions as well as how the ‘medical’ encounter in egg freezing is experienced. The thesis draws on Layder’s theory of social domains, selectively focusing on the domains of contextual resources, situated activity, and psychobiography to explore the macro and micro level aspects of social egg freezing (Layder 2006). Consistent with this theoretical framework, the study utilised a multi-method approach: a content and critical discourse analysis of UK newspaper articles on egg freezing, a demographic questionnaire, and semi-structured interviews with 31 users of egg freezing technology. ‘Career reasons’ were presented as the dominant motivation for social egg freezing in newspaper reports. Highly gendered messages interwoven with discourses of blame and failure were identified throughout the newspaper sample alongside moralising discourses calling for women to act responsibly towards their fertility. Emotive language and specific lexical choices were central in constructing discourses about motherhood and reproductive timing which largely excluded a consideration of the structural, relational and ideological factors which influence reproductive timing and reproductive ‘choice’. The demographic profile of interview participants was similar to that found in existing quantitative studies of social egg freezing. Participants were predominantly single, highly educated women in professional careers, with an average age of 37 at the time of undergoing egg freezing. Egg freezing was constructed by participants in relation to a particular biological project and sense of self. Motherhood was something they wanted to experience at the ‘right time’ with the ‘right partner’. The right time for motherhood was related to the feeling of ‘being ready’, which was often linked to the acquisition of certain preconditions for parenthood. The ‘right’ partner was constructed as someone who reflected certain cultural ideals often associated with ‘new fatherhood’. The absence of such a partner indicated that it was the wrong time to pursue motherhood and thus led women to pursue social egg freezing. Many participants reported that a particular issue or event had acted as a critical factor leading them to undergo egg freezing. These included the breakdown of a relationship or the diagnosis of a health or fertility related problem, thus blurring the conceptual distinction between medical and social egg freezing. Through the use of Layder’s theory of social domains and concepts of neoliberalism and biomedicalisation, the thesis argues that women’s engagement with this technology is influenced by both macro and micro sociological factors including ideologies of parenthood, an individual’s social location, relationships with intimate partners and men’s fathering intentions. When faced with the ‘risk knowledge’ of their declining ovarian reserve, the female users of this technology can be seen as enacting ‘reproductive responsibility’ commensurate with neoliberal values of responsibility, self-actualisation and self-determined action in pursuit of a particular construction of motherhood. This theorisation provides a challenge to current understandings around delayed motherhood and suggests that women’s use of social egg freezing should not be seen simply as the outcome of women’s ‘choice’, but as a process involving a complex interrelation of discourses which contextualises decision making in the reproductive realm. This research has implications for practitioners, regulators, users and potential users of this technology, as well as for researchers concerned with questions of reproductive choice, delayed motherhood and reproductive timing.
229

Integrated receiver channel circuits and structures for a pulsed time-of-flight laser radar

Ruotsalainen, T. (Tarmo) 14 April 1999 (has links)
Abstract This thesis describes the development of integrated structures and circuit implementations for the receiver channel of portable pulsed time-of-flight laser rangefinders for industrial measurement applications where the measurement range is from ∼1 m to ∼100 m to noncooperative targets and the required measurement accuracy is from a few millimetres to a few centimetres. The receiver channel is used to convert the current pulse from a photodetector to a voltage pulse, amplify it, discriminate the timing point and produce an accurately timed logic-level pulse for a time-to-digital converter. Since the length of the laser pulse, typically 5 ns, is large compared to the required accuracy, a specific point in the pulses has to be discriminated. The amplitude of the input pulses varies widely as a function of measurement range and the reflectivity of the target, typically from 1 to 100 ... 1000, so that the gain of the amplifier channel needs to be controlled and the discrimination scheme should be insensitive to the amplitude variation of the input signal. Furthermore, the amplifier channel should have low noise in order to minimize timing jitter. Alternative circuit structures are discussed, the treatment concentrating on the preamplifier, gain control circuitry and timing discriminator, which are the key circuit blocks from the performance point of view. New circuit techniques and structures, such as a fully differential transimpedance preamplifier and a current mode gain control scheme, have been developed. Several circuit implementations for different applications are presented together with experimental results, one of them being a differential BiCMOS receiver channel with a bandwidth of 170 MHz, input referred noise of 6 pA/√Hz and maximum transimpedance of 260 kW. It has an accuracy of about +/- 7 mm (average of 10000 measurements), taking into account walk error with an input signal range of 1:624 and jitter (3s). The achievable performance level using integrated circuit technology is comparable or superior to that of the previously developed commercially available discrete component implementations, and the significantly reduced size and power consumption open up new application areas.
230

Pulsed time-of-flight laser range finder techniques for fast, high precision measurement applications

Kilpelä, A. (Ari) 30 January 2004 (has links)
Abstract This thesis describes the development of high bandwidth (~1 GHz) TOF (time-of-flight) laser range finder techniques for industrial measurement applications in the measurement range of zero to a few dozen metres to diffusely reflecting targets. The main goal has been to improve single-shot precision to mm-level in order to shorten the measurement result acquisition time. A TOF laser range finder consists of a laser transmitter, one or two receivers and timing discriminators, and a time measuring unit. In order to improve single-shot precision the slew-rate of the measurement pulse should be increased, so the optical pulse of the laser transmitter should be narrower and more powerful and the bandwidth of the receiver should be higher without increasing the noise level too much. In the transmitter usually avalanche transistors are used for generating the short (3–10 ns) and powerful (20–100 A) current pulses for the semiconductor laser. Several avalanche transistor types were compared and the optimization of the switching circuit was studied. It was shown that as high as 130 A current pulses are achievable using commercially available surface mount avalanche transistors. The timing discriminator was noticed to give the minimum walk error, when high slew rate measurement pulses and a high bandwidth comparator were used. A walk error of less than +/- 1 mm in an input amplitude dynamic range higher than 1:10 can be achieved with a high bandwidth receiver channel. Adding an external offset voltage between the input nodes of the comparator additionally minimized the walk error. A prototype ~1 GHz laser range finder constructed in the thesis consists of a laser pulser and two integrated ASIC receiver channels with silicon APDs (avalanche photodiodes), crossover timing discriminators and Gilbert cell attenuators. The laser pulser utilizes an internal Q-switching mode of a commercially available SH-laser and produces optical pulses with a pulse peak power and FWHM (full-width-at-half-maximum) of 44 W and 74 ps, respectively. Using single-axis optics and 1 m long multimode fibres between the optics and receivers a total accuracy of +/-2 mm in the measurement range of 0.5–34.5 m was measured. The single-shot precision (σ-value) was 14 ps–34 ps (2–5 mm) in the measurement range. The single-shot precision agrees well with the simulations and is better with a factor of about 3-5 as compared to earlier published pulsed TOF laser radars in comparable measuring conditions.

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