Many computer vision problems, such as object classification, motion estimation or shape registration rely on solving the correspondence problem. Existing algorithms to solve spatial or temporal correspondence problems are usually NP-hard, difficult to approximate, lack flexible models and mechanism for feature weighting. This proposal addresses the correspondence problem in computer vision, and proposes two new spatio-temporal correspondence problems and three algorithms to solve spatial, temporal and spatio-temporal matching between video and other sources. The main contributions of the thesis are: (1) Factorial graph matching (FGM). FGM extends existing work on graph matching (GM) by finding an exact factorization of the affinity matrix. Four are the benefits that follow from this factorization: (a) There is no need to compute the costly (in space and time) pairwise affinity matrix; (b) It provides a unified framework that reveals commonalities and differences between GM methods. Moreover, the factorization provides a clean connection with other matching algorithms such as iterative closest point; (c) The factorization allows the use of a path-following optimization algorithm, that leads to improved optimization strategies and matching performance; (d) Given the factorization, it becomes straight-forward to incorporate geometric transformations (rigid and non-rigid) to the GM problem. (2) Canonical time warping (CTW). CTW is a technique to temporally align multiple multi-dimensional and multi-modal time series. CTW extends DTW by incorporating a feature weighting layer to adapt different modalities, allowing a more flexible warping as combination of monotonic functions, and has linear complexity (unlike DTW that has quadratic). We applied CTW to align human motion captured with different sensors (e.g., audio, video, accelerometers). (3) Spatio-temporal matching (STM). Given a video and a 3D motion capture model, STM finds the correspondence between subsets of video trajectories and the motion capture model. STM is efficiently and robustly solved using linear programming. We illustrate the performance of STM on the problem of human detection in video, and show how STM achieves state-of-the-art performance.

Arthur Stringer (1874-1950) was one of Canada's first professional authors. A prolific writer, he published fifty-nine books, including thirty-eight novels and fifteen volumes of poetry. His work is now out of print and unduly ignored. The dissertation comprises an annotated selection of Stringer's correspondence and a discussion of him as man of letters. The Introduction draws on Stringer's personal papers--including unpublished manuscripts, notebooks, and correspondence--to illustrate his working methods, his relationship with editors and publishers, and the role he played in the literary community. The letters selected show Stringer handling the daily problems of authorship, giving support to other Canadian writers, and (in the letters written for publication) discussing literature and literary criticism. The dissertation includes a chronology, a check-list of Stringer's books, notes on his correspondents, and a list of the repositories of his letters.

国立情報学研究所で電子化したコンテンツを使用している。

国立情報学研究所で電子化したコンテンツを使用している。

The discovery of integrability on both sides of the duality between planar N=4 super Yang-Mills theory and free type IIB string theory in AdS5 × S5 has lead to great progress in our understanding of the AdS/CFT correspondence. Similar integrable structures also appear in the more recent three-dimensional superconformal N=6 Chern-Simons-matter theory constructed by Aharony, Bergman, Jafferis and Maldacena (ABJM), as well as in its gravity dual, type IIA string theory on AdS4 × CP3. However, new interesting complications arise in the AdS4/CFT3 duality. In the conjectured all-loop Bethe equations by Gromov and Vieira the dispersion relation of the magnons has a non-trivial coupling dependence which is parametrized by a function that is only known to the leading order at weak and strong coupling. In the first part of this thesis I discuss our calculations of the next-to-leading correction to this function at weak coupling. We compute this function from four-loop Feynman diagrams in the SU(2) × SU(2) sector of the ABJM model. As a consistency check we have performed the calculation both in a component formalism and using superspace techniques. At strong coupling the fundamental excitations of the integrable model are the giant magnons. The topic of the second part of this thesis is the spectrum of these giant magnons in CP3. Furthermore, I discuss our analyses of the finite-size corrections beyond the asymptotic Bethe ansatz. At weak coupling we have computed the leading four-loop wrapping diagrams in the ABJM model. At the strong coupling side of the duality I discuss our results for the exponentially suppressed finite-size corrections to the energy of giant magnons.

My interest in ethno-archaeology and a Minor Field Study grant brought me to Samoa. There I had a chance to participate in a multinational project “The Pulemelei project, the origins and Development of Monumental architecture”. On the former copra plantation Letolo situated on the SE part of the Island of Savai’i, is an extensive pre-historic settlement with over 3000 remains situated. The remains are now heavily overgrown but when the vegetation was cleared an extensive survey was carried out (1977-78). By using these records my aim is to understand more about how chiefdom society works in pre-historic times as well as in the present. The archaeological study is carried out with the aid of a correspondence analysis using the survey data as well as through a practical fieldwork (excavations) study of the settlement pattern at the Letolo plantation. The settlement shows large variations between the inland and the coastal region and those actions opened for whole new questions and ideas about the Samoan prehistory. During my journey I also got a better understanding for ethno-archaeology, and the problems that can meet us using these analogies and carrying out archaeological studies in a global setting and traditional society. To date, quite limited archaeology has been carried out on Samoa but the archaeological “revival” boosted by the project which started in this area in 2002 has created an opportunity to train the first generation of Samoan archaeologists and give them a good platform to stand on!

Computer vision tasks such as three dimensional (3D) registration, 3D modelling, and 3D object recognition are becoming more and more useful in industry, and have application such as reverse CAD engineering, and robot navigation. Each of these applications use correspondence algorithms as part of their processes. Correspondence algorithms are required to compute accurate mappings between artificial surfaces that represent actual objects or scenes. In industry, inaccurate correspondence is related to factors such as expenses in time and labour, and also safety. Therefore, it is essential to select an appropriate correspondence algorithm for a given surface matching task. However, current research in the area of surface correspondence is hampered by an abundance of applications specific algorithms, and no uniform terminology of consistent model for selecting and/or comparing algorithms. This dissertation presents a correspondence framework for surface matching algorithms. The framework is a conceptual model that is implementable. It is designed to assist in the analysis, comparison, development, and implementation of correspondence algorithms, which are essential tasks when selecting or creating an algorithm for a particular application. The primary contribution of the thesis is the correspondence framework presented as a conceptual model for surface matching algorithms. The model provides a systematic method for analysing, comparing, and developing algorithms. The dissertation demonstrates that by dividing correspondence computation into five stages: region definition, feature extraction, feature representation, local matching, and global matching, the task becomes smaller and more manageable. It also shows that the same stages of different algorithms are directly comparable. Furthermore, novel algorithms can be created by simply connecting compatible stages of different algorithms. Finally, new ideas can be synthesised by creating only the stages to be tested, without developing a while new correspondence algorithm. The secondary contribution that is outlined is the correspondence framework presented as a software design tool for surface matching algorithms. The framework is shown to reduce the complexity of implementing existing algorithms within the framework. This is done by encoding algorithms in a stage-wise procedure, whereby an algorithm is separated into the five stages of the framework. The software design tool is shown to validate the integrity of restructuring existing algorithms within it, and also provide an efficient basis for creating new algorithms. The third contribution that is made is the specification of a quality metric for algorithms comparison. The metric is used to assess the accuracy of the outcomes of a number of correspondence algorithms, which are used to match a wide variety of input surface pairs. The metric is used to demonstrate that each algorithm is application specific, and highlight the types of surfaces that can be matched by each algorithm. Thus, it is shown that algorithms that are implemented within the framework can be selected for particular surface correspondence tasks. The final contribution made is this dissertation is the expansion of the correspondence framework beyond the surface matching domain. The correspondence framework is maintained in its original form, and is used for image matching algorithms. Existing algorithms from three image matching applications are implemented and modified using the framework. It is shown how the framework provides a consistent means and uniform terminology for developing both surface and image matching algorithms. In summary, this thesis presents a correspondence framework for surface matching algorithms. The framework is general, encompassing a comprehensive set of algorithms, and flexible, expanding beyond surface matching to major image matching applications.

Thesis--Lund. / "Project Two-way communication in correspondence education." Includes bibliographical references (p. 116-123).

Thesis (doctoral) - Universität, Stuttgart, 2009. / Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:23:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-14Bitstream added on 2014-06-13T20:11:02Z : No. of bitstreams: 1 ravelli_mn_me_arafcf.pdf: 503371 bytes, checksum: 415dea715919e6ae27164677c8f01d20 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A avaliação do padrão alimentar vem emergindo como uma alternativa nos estudos de epidemiologia nutricional, substituindo as pesquisas baseadas em análise de nutrientes isolados. No entanto, a subnotificação da ingestão, que é fortemente evidenciada entre indivíduos com excesso de peso, influencia a avaliação do consumo energético e pode, consequentemente, induzir a um padrão de consumo alimentar diferente quando comparado ao padrão de consumo de pessoas notificadoras plausíveis. Uma vez que estudos sobre o padrão alimentar ainda não foram avaliados sob a ótica da subnotificação, este trabalho teve por objetivo avaliar a influência da subnotificação do consumo no padrão alimentar, discriminado por grupos alimentares e por nutrientes específicos, entre mulheres obesas da fila de espera da cirurgia bariátrica. Os resultados obtidos foram discutidos em dois artigos científicos, sendo que o primeiro evidenciou a diferença nos padrões alimentares discriminados por contribuição energética diária dos subgrupos alimentares entre as mulheres notificadoras e subnotificadoras do consumo alimentar, e o segundo evidenciou as diferenças entre os grupos de mulheres para os padrões de consumo e itens dos subgrupos alimentares, ambos discriminados pelos nutrientes. Participaram do estudo 412 candidatas à cirurgia bariátrica da Clínica Bariátrica de Piracicaba-SP, Brasil. Dados referentes às informações gerais, e medidas antropométricas foram coletados e utilizados para os cálculos preditivos de Índice de Massa Corporal (IMC), Gasto Energético de Repouso (GER) e Necessidade Energética Total (NET). As informações de consumo alimentar e Nível de Atividade Física (NAF) preditivos foram utilizadas na classificação das mulheres quanto a plausibilidade da notificação do consumo alimentar, confrontando... / Assessment of food patterns has emerged as an alternative in nutritional epidemiology studies, replacing studies based on analysis of individual nutrients. However, food intake underreporting, very common among individuals with excess weight, affects the assessment of energy intake and may, consequently, induce a food intake pattern different from that of plausible energy reporters. Since food pattern studies have not yet been done from the underreporting viewpoint, the objective of this study was to assess the influence of underreporting on the specific food groups and nutrients consumed by obese women waiting for bariatric surgery. The results were discussed in two scientific articles. The first article evidenced the difference between the food patterns of reporters and underreporters according to the daily energy contribution of different food subgroups. The second article evidenced the differences in intake patterns and items in food subgroups, both according to nutrients, between the two groups of women. A total of 412 bariatric surgery candidates of the Bariatric Clinic of Piracicaba, SP, Brazil, participated in the study. General information and anthropometric measurements were collected and used for calculating body mass index (BMI) and predicting resting energy expenditure (REE) and total energy requirement (TER). Food intake and physical activity level (PAL) were used for classifying women regarding the plausibility of the reported food intake, confronting the ratio of reported energy intake EIrep to REE with PAL (EIrep:REE=PAL), considering the variances of this equation’s components. Food subgroups were determined by the Brazilian Food Guide. The food patterns of both groups of women were discriminated according to the food subgroups predefined by exploratory... (Complete abstract click electronic access below)