Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 175-182). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 175-182). Also available on the Internet.

Thesis (Ph. D.)--University of Hong Kong, 2005.

Variational methods have attracted much attention in the past decade. With rigorous mathematical analysis and computational methods, variational minimization models can handle many practical problems arising in image processing, such as image segmentation and image restoration. We propose a two-stage image segmentation approach for color images, in the first stage, the primal-dual algorithm is applied to efficiently solve the proposed minimization problem for a smoothed image solution without irrelevant and trivial information, then in the second stage, we adopt the hillclimbing procedure to segment the smoothed image. For multiplicative noise removal, we employ a difference of convex algorithm to solve the non-convex AA model. And we also improve the non-local total variation model. More precisely, we add an extra term to impose regularity to the graph formed by the weights between pixels. Thin structures can benefit from this regularization term, because it allows to adapt the weights value from the global point of view, thus thin features will not be overlooked like in the conventional non-local models. Since now the non-local total variation term has two variables, the image u and weights v, and it is concave with respect to v, the proximal alternating linearized minimization algorithm is naturally applied with variable metrics to solve the non-convex model efficiently. In the meantime, the efficiency of the proposed approaches is demonstrated on problems including image segmentation, image inpainting and image denoising.

This thesis explores the use of computer vision to facilitate three different processes of a quarry's operation. The first is the blasting process. This is where operators determine where to drill in order to execute an efficient and safe blast. Having an operator manually determine the drilling angles and positions can lead to inefficient and dangerous blasts. By using two cameras, oriented vertically, and separated by a fixed baseline, Structure from Motion techniques can be used to create a scaled 3D model of a bench. This can then be analyzed to provide operators with borehole locations and drilling angles in relation to fixed reference targets. The second process explored is the crushing process, where the rocks pass through different crushers that reduce the rocks into smaller sizes. The crushed rocks are then dropped onto a moving conveyor belt. The maximum dimension of the rocks exiting the crushers should not exceed size thresholds that are specific to each crusher. This thesis presents a 2D vision system capable of estimating the size distribution of the rocks by attempting to segment the rocks in each image. The size distribution, based on the maximum dimension of each rock, is estimated by finding the maximum dimension in the image in pixels and converting that to inches. The third process of the quarry operations explored is where the final product is piled up to form stockpiles. For inventory purposes, operators often carry out a manual estimation of the size of a the stockpile. This thesis presents a vision system capable of providing a more accurate estimate for the size of the stockpile by using Structure from Motion techniques to create a 3D reconstruction. User interaction helps to find the points that are relevant to the stockpile in the resulting point cloud, which are then used to estimate the volume. / Master of Science

O presente trabalho tem por proposta analisar o discurso formulado por um expresidente que pretende reconstruir sua imagem abalada em decorrência do impeachment que sofreu. Ao considerarmos um encontro social, em que os interlocutores interagem face a face, observamos que o interactante procura articular estratégias interacionais, a fim de preservar sua face e protegê-la de eventuais ameaças; ao mesmo tempo, coordena estratégias argumentativas com o intuito de interferir na concepção inicial que seus interlocutores possuem a respeito de sua imagem. Para atingirmos nossos objetivos, consideramos, da Sociolingüística Interacional, as teorias de preservação de faces abordadas por Goffman (1974) e, ao levarmos em conta que estratégias argumentativas também colaboram para a reconstrução da imagem, recorremos aos pressupostos da Teoria da Argumentação, segundo estudos de Perelman e Olbrechts-Tyteca (2002). Com base nesses estudos, partimos para a aplicação dos conceitos em um corpus constituído por uma entrevista televisiva, transmitida pelo Sistema Brasileiro de Televisão (SBT), em agosto de 1998, no \"Programa Livre\", em que o ex-presidente Fernando Collor de Melo é entrevistado por estudantes de ensino médio e cursinho. O corpus foi gravado e transcrito de acordo com as normas publicadas pelo Projeto da Norma Urbana Culta - NURC-SP. / This paper has the purpose of analyzing the discourse delivered by a former president that plans to rebuild his image, since it was shattered as a result of an impeachment sustained by him. Upon considering a social gathering, in which the interlocutors interact face to face, we have noted that the interacting person tries to coordinate interactional strategies in order to preserve his face and protect it against any threats; at the same time, he organizes strategic arguments for the purpose of interfering with the initial assumption that his interlocutors have made in regard to his image. To achieve our goals, we have used, from the Interactional Sociolinguistics, the theory of faces\' preservation as approached by Goffman (1974) and, by taking into account that strategic arguments too cooperate for the reconstruction of the image, we have relied on the assumptions of the Argumentation Theory, according to studies by Perelman & Olbrechts-Tyteca (2002). With basis on this information, we set out to apply the concepts in a corpus made up by a television interview broadcast by SBT, a television network, in August 1998, in the \"Programa Livre\" talk show, in which former President Fernando Collor de Melo was interviewed by high school students. The corpus was recorded and transcribed according to the rules published by Urban Educated Norm Project - NURC - SP

O presente trabalho tem por proposta analisar o discurso formulado por um expresidente que pretende reconstruir sua imagem abalada em decorrência do impeachment que sofreu. Ao considerarmos um encontro social, em que os interlocutores interagem face a face, observamos que o interactante procura articular estratégias interacionais, a fim de preservar sua face e protegê-la de eventuais ameaças; ao mesmo tempo, coordena estratégias argumentativas com o intuito de interferir na concepção inicial que seus interlocutores possuem a respeito de sua imagem. Para atingirmos nossos objetivos, consideramos, da Sociolingüística Interacional, as teorias de preservação de faces abordadas por Goffman (1974) e, ao levarmos em conta que estratégias argumentativas também colaboram para a reconstrução da imagem, recorremos aos pressupostos da Teoria da Argumentação, segundo estudos de Perelman e Olbrechts-Tyteca (2002). Com base nesses estudos, partimos para a aplicação dos conceitos em um corpus constituído por uma entrevista televisiva, transmitida pelo Sistema Brasileiro de Televisão (SBT), em agosto de 1998, no \"Programa Livre\", em que o ex-presidente Fernando Collor de Melo é entrevistado por estudantes de ensino médio e cursinho. O corpus foi gravado e transcrito de acordo com as normas publicadas pelo Projeto da Norma Urbana Culta - NURC-SP. / This paper has the purpose of analyzing the discourse delivered by a former president that plans to rebuild his image, since it was shattered as a result of an impeachment sustained by him. Upon considering a social gathering, in which the interlocutors interact face to face, we have noted that the interacting person tries to coordinate interactional strategies in order to preserve his face and protect it against any threats; at the same time, he organizes strategic arguments for the purpose of interfering with the initial assumption that his interlocutors have made in regard to his image. To achieve our goals, we have used, from the Interactional Sociolinguistics, the theory of faces\' preservation as approached by Goffman (1974) and, by taking into account that strategic arguments too cooperate for the reconstruction of the image, we have relied on the assumptions of the Argumentation Theory, according to studies by Perelman & Olbrechts-Tyteca (2002). With basis on this information, we set out to apply the concepts in a corpus made up by a television interview broadcast by SBT, a television network, in August 1998, in the \"Programa Livre\" talk show, in which former President Fernando Collor de Melo was interviewed by high school students. The corpus was recorded and transcribed according to the rules published by Urban Educated Norm Project - NURC - SP