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Video view interpolation using temporally adaptive 3D meshes / Interpolação de vistas em video utilizando malhas 3D adaptativasFickel, Guilherme Pinto January 2015 (has links)
Esta tese apresenta um novo método para interpolação de vistas em vídeos usando câmeras ao longo de um baseline baseado em uma triangulação 2D. A imagem de referência é primeiramente particionada em regiões triangulares usando informação de bordas e escala, visando colocar vértices ao longo das bordas da imagem e aumentar o número de triângulos em regiões texturadas. Um algoritmo de casamento de regiões é então usado para encontrar a disparidade inicial de cada triângulo, e uma etapa de refinamento é aplicada para mudar a disparidade nos vértices dos triângulos, gerando um mapa de disparidade linear em trechos. Uma simples etapa de pós-processamento é aplicada para conectar os triângulos com disparidade semelhante, gerando uma malha 3D relacionada a cada câmera, que são usadas para gerar novas vistas sintéticas ao longo do mesmo baseline das câmeras. Para gerar vistas com menos artefatos temporais (flickering), foi proposta uma abordagem para atualizar a malha 3D inicial dinamicamente, movendo, removendo e inserindo vértices a cada quadro baseado no fluxo óptico. Esta abordagem permite relacionar triângulos da malha ao longo do tempo, e uma combinação de Modelo Oculto de Markov, aplicado nos triângulos que persistem ao longo do tempo, com Filtro de Kalman, aplicado nos vértices, permite a geração de uma mapa de disparidade com coerência temporal. Com a abordagem proposta, o processo de gerar vistas interpoladas se reduz à trivial tarefa de renderizar uma malha poligonal, algo que pode ser feito muito rapidamente, principalmente quando placas gráficas são utilizadas. Além disso, as vistas geradas não possuem buracos, diferente de muitas técnicas de interpolação de vistas baseadas em pixels que requerem procedimentos de pós-processamento para preencher buracos. Os resultados experimentais indicam que a abordagem proposta foi capaz de gerar vistas interpoladas visualmente coerentes em vídeos desafiadores, com luz natural e movimento de câmera. Além disso, uma avaliação quantitativa usando métricas de qualidade de vídeos mostrou que as sequências de video interpoladas são melhores que abordagens competitivas. / This thesis presents a new method for video view interpolation using multiview linear camera arrays based on 2D domain triangulation. The domain of the reference image is initially partitioned into triangular regions using edge and scale information, aiming to place vertices along image edges and to increase the number of triangles in textured regions. A region-based matching algorithm is then used to find an initial disparity for each triangle, and a refinement stage is applied to change the disparity at the vertices of the triangles, generating a piecewise linear disparity map. A simple post-processing procedure is applied to connect the triangles with similar disparities, generating a full 3D mesh related to each camera (view), which are used to generate the new synthesized views along the cameras baseline. In order to generate views with less temporal flickering artifacts, we propose a scheme to update the initial 3D mesh dynamically, by moving, deleting and inserting vertices at each frame based on optical flow. This approach allows to relate triangles of the mesh across time, and a combination of Hidden Markov Models (HMMs), applied to time-persistent triangles, with the Kalman Filter, applied to vertices, so that temporal consistency can also be obtained. With the proposed framework, view interpolation reduces to the trivial task of rendering polygonal meshes, which can be done very fast, particularly when GPUs are employed. Furthermore, the generated views are hole-free, unlike most point-based view interpolation schemes that require some kind of post-processing procedures to fill holes. Experimental results indicate that our approach was able to generate visually coherent in-between interpolated views for challenging, real-world videos with natural lighting and camera movement.
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Prosecutorial Discretion across Federal Sentencing Reforms: Immediate and Enduring Effects of Unwarranted DisparityJanuary 2015 (has links)
abstract: Contemporary research has examined the relationship between determinate sentencing reforms and unwarranted punishment disparities in states and the federal criminal justice system. Recent investigations suggest that legal developments in federal sentencing—namely, the High Court’s rulings in U.S. v. Booker (2005) and Gall/Kimbrough v. U.S. (2007) which rendered and subsequently reaffirmed the federal guidelines as advisory—have not altered disparities associated with imprisonment outcomes. Punishment disparities following Booker and Gall, particularly racial and ethnic disparities, have been linked to Assistant U.S. Attorneys’ (AUSAs) use of substantial assistance departures. What remains unanswered in the literature is whether the changes in AUSAs’ decision making following the landmark cases has enduring effects and whether the effects are conditioned by defendants’ race/ethnicity and the type of case (guidelines cases or mandatory minimum cases), and whether the use of substantial assistance varies across U.S. District Courts.
Accordingly, these questions are examined using sentencing data from the U.S. Sentencing Commission, coupled with data from the National Judicial Center, U.S. Census Bureau, Uniform Crime Reports, and Interuniversity Consortium for Political and Social Research. This study looks at 465,476 defendants convicted from fiscal year 2001 to fiscal year 2010 across 89 federal districts. A series of multilevel discontinuity regression models are estimated to assess the short-term and long-term effects of the Booker and Gall/Kimbrough decisions on AUSAs’ use of substantial assistance departures, accounting for contextual differences between federal district courts.
The results show that AUSAs are less likely to seek motions for substantial assistance immediately and in the long term in the post-Booker period but are more likely to seek substantial assistance in the long term in the post-Gall/Kimbrough period. These effects, however, are restricted to the models that include all cases and guidelines cases. The interaction models show that Hispanic defendants facing a mandatory minimum sentence are less likely to receive a substantial assistance departure immediately and in the long term following the Court’s Booker decision. Moreover, the use of substantial assistance varies across federal districts. The results are discussed in relation to their implications for theory, courts and sentencing policy, and future research on punishment outcomes. / Dissertation/Thesis / Doctoral Dissertation Criminology and Criminal Justice 2015
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Video view interpolation using temporally adaptive 3D meshes / Interpolação de vistas em video utilizando malhas 3D adaptativasFickel, Guilherme Pinto January 2015 (has links)
Esta tese apresenta um novo método para interpolação de vistas em vídeos usando câmeras ao longo de um baseline baseado em uma triangulação 2D. A imagem de referência é primeiramente particionada em regiões triangulares usando informação de bordas e escala, visando colocar vértices ao longo das bordas da imagem e aumentar o número de triângulos em regiões texturadas. Um algoritmo de casamento de regiões é então usado para encontrar a disparidade inicial de cada triângulo, e uma etapa de refinamento é aplicada para mudar a disparidade nos vértices dos triângulos, gerando um mapa de disparidade linear em trechos. Uma simples etapa de pós-processamento é aplicada para conectar os triângulos com disparidade semelhante, gerando uma malha 3D relacionada a cada câmera, que são usadas para gerar novas vistas sintéticas ao longo do mesmo baseline das câmeras. Para gerar vistas com menos artefatos temporais (flickering), foi proposta uma abordagem para atualizar a malha 3D inicial dinamicamente, movendo, removendo e inserindo vértices a cada quadro baseado no fluxo óptico. Esta abordagem permite relacionar triângulos da malha ao longo do tempo, e uma combinação de Modelo Oculto de Markov, aplicado nos triângulos que persistem ao longo do tempo, com Filtro de Kalman, aplicado nos vértices, permite a geração de uma mapa de disparidade com coerência temporal. Com a abordagem proposta, o processo de gerar vistas interpoladas se reduz à trivial tarefa de renderizar uma malha poligonal, algo que pode ser feito muito rapidamente, principalmente quando placas gráficas são utilizadas. Além disso, as vistas geradas não possuem buracos, diferente de muitas técnicas de interpolação de vistas baseadas em pixels que requerem procedimentos de pós-processamento para preencher buracos. Os resultados experimentais indicam que a abordagem proposta foi capaz de gerar vistas interpoladas visualmente coerentes em vídeos desafiadores, com luz natural e movimento de câmera. Além disso, uma avaliação quantitativa usando métricas de qualidade de vídeos mostrou que as sequências de video interpoladas são melhores que abordagens competitivas. / This thesis presents a new method for video view interpolation using multiview linear camera arrays based on 2D domain triangulation. The domain of the reference image is initially partitioned into triangular regions using edge and scale information, aiming to place vertices along image edges and to increase the number of triangles in textured regions. A region-based matching algorithm is then used to find an initial disparity for each triangle, and a refinement stage is applied to change the disparity at the vertices of the triangles, generating a piecewise linear disparity map. A simple post-processing procedure is applied to connect the triangles with similar disparities, generating a full 3D mesh related to each camera (view), which are used to generate the new synthesized views along the cameras baseline. In order to generate views with less temporal flickering artifacts, we propose a scheme to update the initial 3D mesh dynamically, by moving, deleting and inserting vertices at each frame based on optical flow. This approach allows to relate triangles of the mesh across time, and a combination of Hidden Markov Models (HMMs), applied to time-persistent triangles, with the Kalman Filter, applied to vertices, so that temporal consistency can also be obtained. With the proposed framework, view interpolation reduces to the trivial task of rendering polygonal meshes, which can be done very fast, particularly when GPUs are employed. Furthermore, the generated views are hole-free, unlike most point-based view interpolation schemes that require some kind of post-processing procedures to fill holes. Experimental results indicate that our approach was able to generate visually coherent in-between interpolated views for challenging, real-world videos with natural lighting and camera movement.
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Sink or Swim: Understanding Mexican American Constraints and Facilitators for Swim Lesson ParticipationJanuary 2013 (has links)
abstract: The problem of the study was to investigate constraints and facilitators of Mexican American parents when deciding whether or not to enroll their children in formal swim lessons as a means of drowning prevention. The information obtained by this study (1) helps create awareness about youth drowning incidents and (2) provides insight about Mexican American perspectives and behaviors toward drowning prevention through, or not through as the case may be, youth formal swim lesson participation. This study's sample was purposively selected using typical case and snowball sampling techniques. Individual interviews were conducted with Mexican American parent participants and focus group interviews were conducted with aquatic personnel. From April to August, individual and focus group interviews were conducted in the border towns Sierra Vista, Bisbee, and Douglas in the state of Arizona. There were a total of 25 Mexican American parent participants: 10 had never enrolled their children in swim lessons and 15 had experience enrolling and observing their children in swim lessons. There were 3 focus groups interviews of aquatic personnel experts: Sierra Vista had 6, Bisbee had 7 and Douglas had 9 participants. The theory used to identify and classify the types of constraints and facilitators described in the findings of this study was the Leisure Constraints Theory proposed by Crawford, Jackson and Godbey, 1991. Finding from this study suggest that despite the uncommon perception, Mexican Americans youth are actually participating more in formal swim lessons than they have in past generations. Mexican American families in this sample reported major constraints for formal swim lessons as a reliance on learning form family and friends, swimming at private pools, money, time, and transportation as barriers to participation. Facilitators for Mexican American youth to participate in formal swim lessons are youth drowning awareness, education, lack of parental swimming ability, generational social norm behavior changes, financial assistance and an attitude shift in favor of formal swim lessons. / Dissertation/Thesis / M.S. Recreation and Tourism Studies 2013
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A Study of Disparity in Effort Among Texas School Districts for Debt Service, as Well as for Maintenance and OperationKeller, Annette Smith 12 1900 (has links)
The problem with which this investigation is concerned is that of determining the degree to which fiscal disparity in Texas school districts affects debt service, as well as maintenance and operation and local enrichment. This study has four main purposes: to determine whether the poor school districts are exerting more or less effort for debt service, maintenance and operation and total taxation than are the wealthy districts; to determine how the size of Texas school districts is related to district wealth; to determine the number of Texas school districts that do not levy a tax for debt service; and to provide information for persons interested in school finance matters—namely, legislators, educators, students of finance and lay citizens who may or may not be property taxpayers.
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Video view interpolation using temporally adaptive 3D meshes / Interpolação de vistas em video utilizando malhas 3D adaptativasFickel, Guilherme Pinto January 2015 (has links)
Esta tese apresenta um novo método para interpolação de vistas em vídeos usando câmeras ao longo de um baseline baseado em uma triangulação 2D. A imagem de referência é primeiramente particionada em regiões triangulares usando informação de bordas e escala, visando colocar vértices ao longo das bordas da imagem e aumentar o número de triângulos em regiões texturadas. Um algoritmo de casamento de regiões é então usado para encontrar a disparidade inicial de cada triângulo, e uma etapa de refinamento é aplicada para mudar a disparidade nos vértices dos triângulos, gerando um mapa de disparidade linear em trechos. Uma simples etapa de pós-processamento é aplicada para conectar os triângulos com disparidade semelhante, gerando uma malha 3D relacionada a cada câmera, que são usadas para gerar novas vistas sintéticas ao longo do mesmo baseline das câmeras. Para gerar vistas com menos artefatos temporais (flickering), foi proposta uma abordagem para atualizar a malha 3D inicial dinamicamente, movendo, removendo e inserindo vértices a cada quadro baseado no fluxo óptico. Esta abordagem permite relacionar triângulos da malha ao longo do tempo, e uma combinação de Modelo Oculto de Markov, aplicado nos triângulos que persistem ao longo do tempo, com Filtro de Kalman, aplicado nos vértices, permite a geração de uma mapa de disparidade com coerência temporal. Com a abordagem proposta, o processo de gerar vistas interpoladas se reduz à trivial tarefa de renderizar uma malha poligonal, algo que pode ser feito muito rapidamente, principalmente quando placas gráficas são utilizadas. Além disso, as vistas geradas não possuem buracos, diferente de muitas técnicas de interpolação de vistas baseadas em pixels que requerem procedimentos de pós-processamento para preencher buracos. Os resultados experimentais indicam que a abordagem proposta foi capaz de gerar vistas interpoladas visualmente coerentes em vídeos desafiadores, com luz natural e movimento de câmera. Além disso, uma avaliação quantitativa usando métricas de qualidade de vídeos mostrou que as sequências de video interpoladas são melhores que abordagens competitivas. / This thesis presents a new method for video view interpolation using multiview linear camera arrays based on 2D domain triangulation. The domain of the reference image is initially partitioned into triangular regions using edge and scale information, aiming to place vertices along image edges and to increase the number of triangles in textured regions. A region-based matching algorithm is then used to find an initial disparity for each triangle, and a refinement stage is applied to change the disparity at the vertices of the triangles, generating a piecewise linear disparity map. A simple post-processing procedure is applied to connect the triangles with similar disparities, generating a full 3D mesh related to each camera (view), which are used to generate the new synthesized views along the cameras baseline. In order to generate views with less temporal flickering artifacts, we propose a scheme to update the initial 3D mesh dynamically, by moving, deleting and inserting vertices at each frame based on optical flow. This approach allows to relate triangles of the mesh across time, and a combination of Hidden Markov Models (HMMs), applied to time-persistent triangles, with the Kalman Filter, applied to vertices, so that temporal consistency can also be obtained. With the proposed framework, view interpolation reduces to the trivial task of rendering polygonal meshes, which can be done very fast, particularly when GPUs are employed. Furthermore, the generated views are hole-free, unlike most point-based view interpolation schemes that require some kind of post-processing procedures to fill holes. Experimental results indicate that our approach was able to generate visually coherent in-between interpolated views for challenging, real-world videos with natural lighting and camera movement.
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Intermediate View Interpolation of Stereoscopic Images for 3D-DisplayThulin, Oskar January 2006 (has links)
This thesis investigates how disparity estimation may be used to visualize an object on a 3D-screen. The first part looks into different methods of disparity estimation, and the second part examines different ways to visualize an object from one or several stereo pairs and a disparity map. Input to the system is one or several stereo pairs, and output is a sequence of images of the input scene but from more angles. This sequence of images can be shown on Setred AB's 3D-screen. The system has high real time demands and the goal is to do the disparity estimation and visualization in real time. In the first part of the thesis, three different ways to calculate disparity maps are implemented and compared. The three methods are correlation-based, local structure-based and phase-based techniques. The correlation-based methods cannot satisfy the real-time demands due to the large number of 2D-convolutions required per pixel. The local structure-based methods have too much noise and cannot satisfy the quality requirements. Therefore, the best method by far is the phase-based method. This method has been implemented in Matlab and C and comparisons between the different implementations are presented. The quality of the disparity maps is satisfying, but the real-time demands cannot yet be fulfilled. The future work is therefore to optimize the C code and move some functions to a GPU, because a GPU can perform calculations in parallel with the CPU. Another reason is that many of the calculations are related to resizing and warping, which are well-suited to implementation on a GPU.
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Porovnanie českého a slovenského trhu práce v rokoch 1993 – 2016 / Comparison of the Czech and Slovak labor market between 1993 and 2016Stankovič, František January 2017 (has links)
The labor market has overtaken huge changes in the Czech republic and Slovakia in the last quarter of a century. This diploma theses explains that the structure of the labor market is a dynamic concept that reacts not only to local economic factors, but also to changes in the European and world context. Czech and Slovak labor market has currently different regional disparities. In Slovakia, the problem of regional disparities and the significant polarization of the east and west of the country is much more urgent and significantly affects not only overall unemployment in the Slovak Republic but also the political and economic situation. This diploma thesis analyzes the origins of regional disparities and major changes in the labor market that have taken place in both countries since 1993 until present, and defines that the main cause is mono-industrialization in the second half of the 20th century.
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BLACK WOMEN’S PERSPECTIVES ON BREAST CANCER DETECTION MESSAGINGDamron, Denise M. 01 January 2017 (has links)
A qualitative approach was used to explore the influence of mass media campaigns on Black women’s perceptions of breast cancer. The primary purpose of this study was to address the high breast cancer mortality rate among young Black women, thus informing strategies to increase awareness of risk and encourage prevention activities. Black women have higher incidence rates before age 45 and are more likely to die from breast cancer at every age. Although the breast cancer mortality variance has been linked to socioeconomic status, studies have shown that differences in cancer knowledge and beliefs persist even when educational and socioeconomic measures are statistically controlled.
Because little is known about how various ethnic group members form ideas about breast cancer in the U.S., semi-structured interviews were conducted with 27 Black women between the ages of 30 and 40 to determine their knowledge and beliefs about breast cancer, as well as their personal perceptions of susceptibility to being diagnosed with breast cancer, in order to illuminate the interplay of culture and health belief systems on participants’ understanding of breast cancer messaging.
To explore the potentially complex dynamics involved in how young Black women come to construct meanings about breast cancer, a theoretical framework that coupled Cultural Models Theory with the Risk Perception Attitude framework was used to address how health campaigns influence the behaviors and breast cancer detection experiences of Black women.
Findings from the study revealed that young Black women’s perceptions of breast cancer are primarily driven by personal experiences, as opposed to mass media influences. The Black women in this study had a lack of knowledge of risk and prevention factors and did not perceive themselves to be affected by breast cancer due to their young age. In spite of cultural taboos against discussing health issues with family and friends, the women in this study tended to take responsibility for their health and were proactive in seeking and acting on health information.
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Cubic-Panorama Image Dataset Analysis for Storage and TransmissionSalehi Doolabi, Saeed January 2013 (has links)
This thesis involves systems for virtual presence in remote locations, a field referred to as telepresence. Recent image-based representations such as Google map's street view provide a familiar example. Several areas of research are open; such image-based representations are huge in size and the necessity to compress data efficiently for storage is inevitable. On the other hand, users are usually located in remote areas, and thus efficient transmission of the visual information is another issue of great importance.
In this work, real-world images are used in preference to computer graphics representations, mainly due to the photorealism that they provide as well as to avoid the high computational cost required for simulating large-scale environments. The cubic format is selected for panoramas in this thesis. A major feature of the captured cubic-panoramic image datasets in this work is the assumption of static scenes, and major issues of the system are compression efficiency and random access for storage, as well as computational complexity for transmission upon remote users' requests.
First, in order to enable smooth navigation across different view-points, a method for aligning cubic-panorama image datasets by using the geometry of the scene is proposed and tested. Feature detection and camera calibration are incorporated and unlike the existing method, which is limited to a pair of panoramas, our approach is applicable to datasets with a large number of panoramic images, with no need for extra numerical estimation.
Second, the problem of cubic-panorama image dataset compression is addressed in a number of ways. Two state-of-the-art approaches, namely the standardized scheme of H.264 and a wavelet-based codec named Dirac, are used and compared for the application of virtual navigation in image based representations of real world environments. Different frame prediction structures and group of pictures lengths are investigated and compared for this new type of visual data. At this stage, based on the obtained results, an efficient prediction structure and bitstream syntax using features of the data as well as satisfying major requirements of the system are proposed.
Third, we have proposed novel methods to address the important issue of disparity estimation. A client-server based scheme is assumed and a remote user is assumed to seek information at each navigation step. Considering the compression stage, a fast method that uses our previous work on the geometry of the scene as well as the proposed prediction structure together with the cubic format of panoramas is used to estimate disparity vectors efficiently.
Considering the transmission stage, a new transcoding scheme is introduced and a number of different frame-format conversion scenarios are addressed towards the goal of free navigation. Different types of navigation scenarios including forward or backward navigation, as well as user pan, tilt, and zoom are addressed. In all the aforementioned cases, results are compared both visually through error images and videos as well as using the objective measures. Altogether free navigation within the captured panoramic image datasets will be facilitated using our work and it can be incorporated in state-of-the-art of emerging cubic-panorama image dataset compression/transmission schemes.
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