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Synchronization of a Multi Camera SystemVibeck, Alexander January 2015 (has links)
In a synchronized multi camera system it is imperative that the synchronization error between the different cameras is as close to zero as possible and the jitter of the presumed frame rate is as small as possible. It is even more important when these systems are used in an autonomous vehicle trying to sense its surroundings. We would never hand over the control to a autonomous vehicle if we couldn't trust the data it is using for moving around. The purpose of this thesis was to build a synchronization setup for a multi camera system using state of the art RayTrix digital cameras that will be used in the iQMatic project involving autonomous heavy duty vehicles. The iQMatic project is a collaboration between several Swedish industrial partners and universities. There was also software development for the multi camera system involved. Different synchronization techniques were implemented and then analysed against the system requirements. The two techniques were hardware trigger i.e. external trigger using a microcontroller, and software trigger using the API from the digital cameras. Experiments were conducted by testing the different trigger modes with the developed multi camera software. The conclusions show that the hardware trigger is preferable in this particular system by showing more stability and better statistics against the system requirements than the software trigger. But the thesis also show that additional experiments are needed for a more accurate analysis. / iQMatic
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Synchrophasor events in the Western Electricity Coordinating Council (WECC) gridRangel Werdene, Alexandro 17 June 2011 (has links)
Synchronized phasor measurements, or synchrophasors, allow the measurement of voltage phase angle and frequency, and through the comparison of two or more phasor the stability of the grid can be studied. The acquisition of synchrophasors in possible using Phasor Measurement Units (PMUs) and Global Positioning System Technology (GPS).
The purpose of this research is to study synchrophasor events in the Western Electricity Coordinating Council (WECC) grid. Several studies have been made in the Texas grid, and that allows a comparison of events in both grids.
During this study, five different types of synchrophasor events were observed. The first type of events, which consist of a change in phase angle difference value followed by damped oscillations has also been observed in the Texas grid; however, the other 4 types of events are not common occurrences in the Texas grid. The characteristics of each of the five types of synchrophasor events have been analyzed in this thesis. / text
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Imagery Use in Synchronized SwimmingRanucci, Jill January 2007 (has links)
The purpose of this study was to examine the utilization of imagery and the impact of imagery use on collegiate synchronized swimmers. Swimmers (N=165) completed The Sport Imagery Questionnaire (Hall et al. 2005), reporting their frequency of imaging. Interviews were conducted (N=11) to further ascertain why and when synchronized swimmers use imagery and mechanisms they employ for more effective imaging experiences. Exploratory factor analyses indicated three of Hall et al's (2005) five subscales showed significant differences between skill level groups. Specifically, motivational specific functions of imagery data showed significant differences between elite swimmers and the other three groups (advanced, intermediate, and novice). Cognitive specific and motivational general-mastery functions of imagery data indicated significant differences between elite and novice swimmers, suggesting that novice swimmers are less likely to use these subscales of imagery compared to elite swimmers. Qualitative data provided evidence of elite swimmers having more sophisticated and developed applications of imaging skills. The results suggest the global implications of this study and how imagery improves synchronized swimming training programs. Key findings include: Each progressive skill level had better imaging skills and utilization than the lower levels Years experience, repetition, and training impact synchronized swimmers use of imagery The very nature of certain common synchronized swimming drills such as "think-throughs and land drill" elicit imaging training The sport of synchronized swimming is an excellent instrument to research imaging training techniques.
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Local and global mermaids : the politics of "pretty swimming"Thomas, Laura Michelle 11 1900 (has links)
This thesis considers the perceived athleticism of synchronized swimming by looking
at the implications of representations of Esther Williams and "pretty swimming" in popular
culture, the allocation of space for women's sport in a local public swimming pool, and an
inaugural championship event. Focusing on the first British Columbia (BC) synchronized
swimming championships, which were held on February 5, 1949 at Crystal Pool in
Vancouver, it shows that images of synchronized swimming as "entertainment" facilitated
the development of a new arena of competition for BC women, but that this was
accompanied, in effect, by a trivialization of the accomplishments of organizers and athletes.
Chapter One examines the construction of a "global" mermaid by analysing Esther
Williams' first film, Bathing Beauty (1944), as a typical example of the Metro-Goldwyn-
Mayer (MGM) aquamusical, a genre that produced images of synchronized swimming as
frivolous entertainment. Chapter Two considers how these sorts of images affected the
allocation of physical space at Crystal Pool, Vancouver's only indoor public swimming pool
at the time, for women's sport. Chapter Three introduces two women who were involved in
the 1949 BC synchronized swimming championships: May Brown, who at the time was a
University of British Columbia (UBC) Physical Education instructor and synchronized
swimming judge, and Maureen Bray (Hibberson), a UBC student who won the individual
championship event. Their recollections provide an important corrective to the "pretty
swimming" stereotype by demonstrating that these women used the cultural and physical
space allotted to them to create a new sport for local women. The final chapter also includes
episodes from my personal experiences as a synchronized swimmer in BC during the 1980s
to underscore the complicated and conflicted heritage for synchronized swimmers in BC
represented by the legacy of the 1949 championships and the MGM aquamusical.
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Local and global mermaids : the politics of "pretty swimming"Thomas, Laura Michelle 11 1900 (has links)
This thesis considers the perceived athleticism of synchronized swimming by looking
at the implications of representations of Esther Williams and "pretty swimming" in popular
culture, the allocation of space for women's sport in a local public swimming pool, and an
inaugural championship event. Focusing on the first British Columbia (BC) synchronized
swimming championships, which were held on February 5, 1949 at Crystal Pool in
Vancouver, it shows that images of synchronized swimming as "entertainment" facilitated
the development of a new arena of competition for BC women, but that this was
accompanied, in effect, by a trivialization of the accomplishments of organizers and athletes.
Chapter One examines the construction of a "global" mermaid by analysing Esther
Williams' first film, Bathing Beauty (1944), as a typical example of the Metro-Goldwyn-
Mayer (MGM) aquamusical, a genre that produced images of synchronized swimming as
frivolous entertainment. Chapter Two considers how these sorts of images affected the
allocation of physical space at Crystal Pool, Vancouver's only indoor public swimming pool
at the time, for women's sport. Chapter Three introduces two women who were involved in
the 1949 BC synchronized swimming championships: May Brown, who at the time was a
University of British Columbia (UBC) Physical Education instructor and synchronized
swimming judge, and Maureen Bray (Hibberson), a UBC student who won the individual
championship event. Their recollections provide an important corrective to the "pretty
swimming" stereotype by demonstrating that these women used the cultural and physical
space allotted to them to create a new sport for local women. The final chapter also includes
episodes from my personal experiences as a synchronized swimmer in BC during the 1980s
to underscore the complicated and conflicted heritage for synchronized swimmers in BC
represented by the legacy of the 1949 championships and the MGM aquamusical. / Education, Faculty of / Educational Studies (EDST), Department of / Graduate
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Efeitos do modelo na aprendizagem do nado sincronizado / Effects of model in the motor learning process of synchronized swimming skillsMeico Fugita 23 March 2010 (has links)
O objetivo do presente estudo foi investigar os efeitos do tipo de modelo, boneca e humano, na aprendizagem das habilidades motoras do nado sincronizado, mais especificamente na figura tina (Experimento 1), bem como os efeitos da ordem da apresentação do modelo, boneca-humano ou humano-boneca na aprendizagem da mesma figura (Experimento 2). Participaram do Experimento 1, 20 sujeitos, partindo dos seguintes critérios de inclusão: voluntários do sexo feminino, com idade média de 23,1 anos (DP= 4,1), adaptados ao meio aquático, capazes de deslocar-se na parte rasa da piscina, de flutuar com auxílio das mãos, sem experiência anterior com qualquer das habilidades do nado sincronizado. A tarefa consistiu na execução da tina, que compreende a execução de uma sequência composta por 3 posições e 2 movimentos de transição: (1) Posição Inicial; (2) Transição para a tina; (3) Posição de Tina; (4) Transição para a posição final; e, (5) Posição Final. Os sujeitos foram distribuídos em dois grupos de 10 participantes cada, o grupo modelo boneca (GB) e o grupo modelo humano (GH). Após um pré-teste composto de seis tentativas consecutivas de execução da tina a partir de instrução verbal, todos executaram 60 tentativas a partir de demonstração e instrução verbal. As demonstrações tanto do modelo boneca como do modelo humano foram fornecidas a cada tentativa, por vídeo. Após intervalo de 10 minutos, todos foram submetidos a um pós-teste, também composto de seis tentativas consecutivas de execução da tina a partir de instrução verbal. No dia seguinte, todos os sujeitos, independente do grupo foram submetidos ao teste de retenção, composto de dois blocos de 6 tentativas, sem qualquer tipo de instrução. A amostra do Experimento 2 foi constituída por 20 sujeitos, voluntários do sexo feminino, com idade média de 21,6 anos (DP= 2,8), adaptados ao meio aquático, capazes de deslocar-se na parte rasa da piscina, de flutuar com auxílio das mãos, sem experiência anterior com qualquer das habilidades do nado sincronizado, cuja tarefa era a mesma do Experimento 1, a execução da tina. Foram formados dois grupos de 10 participantes, sendo um deles com modelo boneca seguido de modelo humano e outro com modelo humano seguido de boneca. Após a aplicação de pré-teste, somente com instrução verbal, cada grupo executou 10 blocos de aquisição. Dez minutos após a fase de aquisição, os sujeitos executaram um bloco pós-teste, em que só foi fornecida instrução verbal, seguido, no dia seguinte, de dois blocos de teste de retenção, cada um constituído de seis tentativas. Entre os blocos 1 e 5 da fase de aquisição, as participantes receberam uma demonstração a cada tentativa de seu primeiro modelo, boneca ou humano, de acordo com seu grupo. Do bloco 6 ao 10 da fase de aquisição, as participantes receberam uma demonstração a cada tentativa do segundo modelo, humano ou boneca. Os resultados mostraram que nas medidas de desempenho global e de desempenho por componente não houve efeito do tipo de modelo, boneca ou humano (Experimento 1) e da ordem de apresentação do modelo na aprendizagem da tina do nado sincronizado. Nesse sentido concluiu-se que o modelo apresentado na demonstração associado à instrução verbal, não afeta a aprendizagem da tina, podendo ser utilizada a boneca e ou o modelo humano / The objective of the present study was to investigate the effects of the type of model, synchro doll and human, in the motor learning process of Synchronized Swimming skills, particularly the tub figure (Experiment 1), as well as the effects of the sequence of models presentation in the learning process of the tub, synchro doll followed by the human model, or the human model prior to the synchro doll (Experiment 2). Experiment I was based on the performance of 20 female volunteer subjects, average age 23,1 years old (SD =4,1), adapted to aquatic environment, able to move on the shallow part of the pool and to fluctuate without using their hands. The task consisted of tub figure of the Synchronized Swimming consisting of 5 positions and 2 transition movements: starting position, tub transition, tub position, final transition and final position. After a pre-test in which all made 6 consecutive trials with verbal task description, the subjects were distributed in two groups consisting of 10 participants which, and made 60 trials with verbal task description and one demonstration per trial, the latter consisting of video instruction showing either a synchro doll model, or a human model. After 10 minutes all were submitted to a post-test, which consisted of 6 consecutive trials with verbal instructions only. On the following day, the subjects of both groups were submitted to a retention test, composed of two sessions of 6 consecutive trials with no instructions at all. In Experiment 2, 20 novice female subjects, average age 21,6 years old (SD = 2,8), adapted to aquatic environment, able to move on the shallow part of the pool and to fluctuate without using their hands had the same task as in Experiment 1, the performance of the five task components of the tub: starting position, tub transition, tub position, final transition and final position. Two groups of 10 participants were formed, one of them having the synchro doll model prior to the human model, and the other with the human model followed by the synchro doll model. After the pre-test in which all made 6 consecutive trials with verbal task description, each subject was submitted to 10 acquisition sessions. Ten minutes after those, the subjects were submitted to a post-test with verbal instructions only and, on the following day, 2 sessions of retention tests, consisting of 6 trials which, with no instructions at all. During the acquisition sessions 1 to 5 the subjects received one demonstration per trial of the first model, either synchro doll or human, according to their group, During the acquisition sessions 6 to 10 the participants received one demonstration per trial of the other model, either human or synchro doll. The results show that the type of model and the presentation sequence did not affect the global performance nor the performance of the components. So it was concluded that the model presented in demonstration associated to the verbal instructions does not affect tub learning, making it possible to use either the doll or the human model in any sequence
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Inter-Area Oscillation Damping with Power System Stabilizers and Synchronized Phasor MeasurementsSnyder, Aaron Francis 10 February 1997 (has links)
Low frequency oscillations are detrimental to the goals of maximum power transfer and optimal power system security. A contemporary solution to this problem is the addition of power system stabilizers to the automatic voltage regulators on the generators in the power system. The damping provided by this additional stabilizer provides the means to reduce the inhibiting effects of the oscillations.
This thesis is an investigation of the use of synchronized phasor measurements as input signals for power system stabilizers installed on the generators of a two-area, 4-machine test power system. A remote measurement feedback controller has been designed and placed in the test power system. Synchronized phasor measurements from optimally sited measurement units were shown to improve the damping of low-frequency inter-area oscillations present in the test system when the proposed controller was included in the generator feedback control loop. The benefit of the damping of these oscillations was evident through the ability to increase the tie-line power flowing in the test system once the proposed control scheme was implemented. Time-domain simulations were used to verify the robustness of the proposed control during severe events, such as a short- circuit or sudden large variations of load. / Master of Science
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Mechanism and function of synchronized hatching in Pentatomidae (Insecta: Heteroptera) / カメムシ科における同期孵化のメカニズムと機能Endo, Jun 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20952号 / 理博第4404号 / 新制||理||1633(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 沼田 英治, 准教授 森 哲, 教授 中川 尚史 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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Frequency Pulling of the van der Pol OscillatorOutram, Ian Hugh 05 1900 (has links)
<p> The frequency pulling of the van dcr Pol nonlinear oscillator due to an external forcing signal is investigated. The nonlinearity is of the zero-memory symmetric-cut-off type following a cube law.</p> <p> An experimental oscillator was built, and curves of the frequency shift of the oscillator fundamental against the magnitude of the input forcing signal are shown, both for a sinusoidal input and for a narrow band noise input. An empirical result is derived.</p> <p> The case of the sinusoidal input is examined theoretically. The importance of harmonic and intermodulation frequencies in the oscillator output is shown, and relations giving the oscillator frequency shift are given for small forcing amplitudes and for large amplitudes when
the oscillator is nearly synchronized.</p> / Thesis / Master of Engineering (MEngr)
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Next Generation Frequency Disturbance Recorder Design and Timing AnalysisWang, Lei 16 June 2010 (has links)
In recent years, the subject of wide-area synchronized measurements has gained a significant amount of attention from the power system researchers. All of this started with the introduction of the Phasor Measurement Unit (PMU), which added a new perspective in the field of wide-area measurement systems (WAMS). With the ever evolving technologies over the years and the need for a more cost effective solution for synchronized frequency measurements, the Frequency Monitoring Network (FNET) was developed and introduced by the Power IT laboratory at Virginia Tech. The FNET is comprised of many Frequency Disturbance Recorders (FDR) geographically distributed throughout the United States. The FDR is a dedicated data acquisition device deployed at the distribution level, which allows for a lower cost and easily deployable WAMS solution. With Internet connectivity and GPS timing synchronization, the FDR provides high accuracy frequency, voltage magnitude and voltage angle data to the remote servers.
Although the current FDR design is up to the standard in terms of the measurement accuracy and portability, it is of interest to further the research into alternative architectures and leverage the ever advancing technologies in high speed computing. One of the purposes of this dissertation is to present novel design options for a new generation of FDR hardware design. These design options will allow for more flexibility and to lower reliance on some vendor specific components. More importantly, the designs seek to allow for more computation processing capabilities so that more accurate frequency and angle measurements may be obtained.
Besides the fact that the accuracy of frequency and angle measurement is highly dependent on the hardware and the algorithm, much can be said about the role of timing synchronization and its effects on accurate measurements. Most importantly, the accuracy of the frequency and angle estimation is highly dependent on the sampling time of local voltage angles. The challenges to accurate synchronized sampling are two folds. One challenge has to do with the inherent fallbacks of the GPS receiver, which is relatively high cost and limited in availability when the satellite signal is degraded. The other challenge is related to the timing inaccuracies of the sampling pulses, which is attributed to the remainder that results from the imperfect division of the processor counter. This dissertation addresses these issues by introducing the implementation of the high sensitivity (indoor) GPS and network timing synchronization, which aims to increase the availability of frequency measurements in locations that would not have been possible before. Furthermore, a high accuracy timing measurement system is introduced to characterize the accuracy and stability of the conventional crystal oscillator. To this end, a new method is introduced in close association with some prior work in generating accurate sampling time for FDR. Finally, a new method is introduced for modeling the FDR based on the sampling time measurements and some results are presented in order to motivate for more research in this area. / Ph. D.
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