Tesis para optar al grado de Magíster en Minería / La excavación de galerías subterráneas es una actividad fundamental en las minas explotadas por hundimiento, debido a que abre los frentes de trabajo para todas las actividades que se ejecutan posteriormente. Por tal razón, mejorar los tiempos de ejecución de esta tarea permitirá adelantar la entrada en producción de un proyecto de explotación de minería subterránea. Así mismo, la prefabricación de elementos de hormigón armado como solución a la construcción de infraestructura minera necesaria para la explotación de sectores en preparación, nace como una alternativa a la construcción de obras civiles convencionales. Este tipo de soluciones transforman la tarea de construcción in situ en una tarea de montaje, donde los elementos son fabricados en una planta por métodos de producción industrial quedando disponible para ser transportados a la obra y montados en el lugar definido. Sin embargo, su utilización en infraestructura minera aún es incipiente debido a la escasa información acerca de los beneficios, ventajas y mejoras en la productividad que se logran con este nuevo sistema. El presente trabajo de tesis tiene como objetivo principal reducir los costos y mejorar rendimientos de las actividades de Preparación Minera, estableciendo una metodología a través de la optimización de los procesos de Desarrollo y Construcción de infraestructura, con el fin de adelantar la disposición de mineral a la producción. Para llevar a cabo este estudio, del punto de vista técnico, se efectuó una revisión bibliográfica relacionada con la excavación de galerías subterráneas mediante la metodología Desarrollo Rápido (Rapid development) y la industrialización y prefabricación de elementos estructurales de hormigón, su aplicación en proyectos de infraestructura y tunelería civil. De la misma manera, desde el punto de vista de la gestión, se revisó detalladamente cómo se realiza funcionalmente la preparación minera a través del estudio en profundidad de la Dirección de Proyecto Preparación de Minas, entidad encargada de ejecutar los proyectos al interior de la División El Teniente. El diagnóstico integral de la preparación minera en la División El Teniente, donde se analiza cómo se ejecuta esta actividad del punto de vista de un proyecto operacional, permitió plantear una hipótesis sobre la optimización de los procesos de preparación minera basado en dos ámbitos: la gestión y las operaciones de desarrollo y construcción. En el ámbito de gestión se realizó un plan estratégico, basado en el plan de negocio divisional PND 2010, que entrega la cantidad de obra necesaria para sustentar la producción en el quinquenio 2011-2015, el que permitió establecer una mirada a mediano y largo plazo para la continuidad de esta actividad en la División El Teniente. En el ámbito de operaciones, se trabajó en las actividades más relevantes; por una parte la excavación de galerías o desarrollos horizontales y por otra dos tipos de obras civiles que representan la mayor inversión anual en la preparación minera, la construcción de puntos de extracción y muros de confinamiento. El resultado de este estudio, permite concluir que si bien es cierto, la aplicación de la metodología de desarrollo rápido es factible en el método de hundimiento por Block Caving de la mina El Teniente, ésta no es aplicable en su totalidad debido a las solicitaciones dinámicas asociadas a los eventuales estallidos de roca que impiden la eliminación de la malla como solución de fortificación y las interferencias que generan los distintos tipos de turnos y aislaciones por tronadura que se ejecutan en horarios definidos para las faenas de extracción de mineral, los que no son compatibles con los turnos de obras o preparación minera. En el caso de las obras civiles las pruebas se validaron con resultados superiores a las expectativas planteadas, es decir, ahorros de costos superiores al 20 % para los distintos elementos de infraestructura estudiados, donde además se obtuvieron mejoras intangibles como la descongestión de los portales de ingreso a la mina (ADIT) y la logística de abastecimiento de materiales.

This dissertation introduces three novel multiuser detection approaches in Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems by blind signal separation (BSS) techniques. The conventional methodologies for multiuser detection have to retransmit channel state information (CSI) constantly from the transmitter in MIMO ODFM systems at the cost of economic efficiency, because they require more channel resources to improve the communication quality. Compared with the traditional methodologies, the proposed BSS methods are relatively efficient approaches without the unnecessary retransmission of channel state information. The current methodologies apply the space-time coding or the spatial multiplexing to implement an MIMO OFDM system, which requires relatively complex antenna design and allocation in the transmitter. The proposed Spatial Division Multiple Access (SDMA) method enables different mobile users to share the same bandwidth simultaneously in different geographical locations, and this scheme requires only one antenna for each mobile user. Therefore, it greatly simplifies the antenna design and allocation. The goal of this dissertation is to design and implement three blind multiuser detection schemes without knowing the channel state information or the channel transfer function in the SDMA-based uplink MIMO OFDM system. The proposed scenarios include: (a) the BSS-only scheme, (b) the BSS-Minimum Mean Square Error (MMSE) scheme, and (c) the BSS-Minimum Bit Error Ratio (MBER) scheme. The major contributions of the dissertation include: (a) the three proposed schemes save the commercially expensive cost of channel resources; (b) the proposed SDMA-based uplink MIMO OFDM system simplifies the requirements of antennas for mobile users; (c) the three proposed schemes obtain high parallel computing efficiency through paralleled subcarriers; (d) the proposed BSS-MBER scheme gains the best BER performance; (e) the proposed BSS-MMSE method yields the best computational efficiency; and (f) the proposed BSS-only scenario balances the BER performance and computational complexity.

Com a finalidade de melhorar o desempenho e de entender os atletas, atualmente tem aumentado a utilização de métodos de avaliação psicológica, os quais chegaram ao esporte e passaram a ocupar espaço nos planejamentos de equipes, auxiliando na tomada de decisões relacionadas ao desempenho esportivo. A Escala de Humor de Brunel (BRUMS) avalia a disposição mental e o humor do indivíduo, contribuindo para a individualização do treinamento. O objetivo desta pesquisa foi o de relacionar estas subescalas de estados de humor ao desempenho esportivo de 30 jogadores profissionais de Goalball no período de treinamento e competição (jogo) estratificados por sexo, nível competitivo, posição e titularidade. Os resultados demonstraram correlações significativas entre variáveis de humor e de desempenho esportivo nas situações de treino e jogo, destacaram as diferenças de estados de humor entre os sexos, porém não no desempenho, demonstraram que não existem diferenças significativas no desempenho esportivo de atletas de nível nacional e internacional, que a posição de ala possui característica ofensiva e a de pivô, defensiva, e ainda que atletas reservas não diferem no desempenho esportivo, porém diferem nos estados de humor quanto aos titulares. Pode-se concluir que se faz necessária avaliação constante dos estados de humor juntamente com o desempenho esportivo para que se obtenha o melhor rendimento de cada atleta / Sports performance improvement depends on athletes behavior in training and competition situations. Several methods of psychological assessment are used on sports teams, helping coaches and team staffs make decisions about players conditions and their performance enhancement. Brunel\'s Mood Scale (BRUMS) evaluates individual mental and mood states, which may lead to training and periodization changes on sports performance. The aim of this study was to relate these mood scales to sport performance of 30 professional Goalball players during training and competition, stratified by sex, competitive level, position and ownership. The results demonstrated significant correlations among mood and sport performance variables in training and competition, highlighted the differences in mood states between men and women but not in performance, showed that national and international players do not differ regarding athletic performance, indicated that that wing players tend to attack more than defend while pivots tend to defend more than attack and finally revealed that reserves differ from holders in mood states but do not differ from holders regarding sport performance. It can be concluded that it is important to evaluate mood states of athletes as a way to enhance sports performance

O objetivo deste estudo foi avaliar aspectos da aptidão física de 24 adolescentes cegos (12 de escolas regulares e 12 de uma escola especial) e sua percepção sobre as aulas de educação física. Também foram analisadas as atitudes de noventa professores de educação física com relação à inclusão de alunos com deficiências nas escolas regulares. Quanto à atitude dos professores, verificou-se que as maiores preocupações foram sobre sua falta de preparo e a escassez de estrutura da escola para receber, de forma adequada, alunos com deficiências. No que se refere aos testes de aptidão física, os alunos da escola especial apresentaram resultados superiores e uma melhor evolução em praticamente todas as variáveis pesquisadas. Quanto à aceitação e à competência percebidas, novamente os alunos da escola especial demonstraram resultados mais positivos do que seus colegas de escolas inclusivas, afirmando serem mais participativos nas aulas e sentindo-se mais bem aceitos pelos colegas e pelo professor. Por fim, com relação ao conceito dos adolescentes cegos sobre educação física, observou-se que aqueles da escola especial apresentaram um conceito mais relacionado à saúde, à convivência com os amigos e ao ganho de independência. Já os das escolas inclusivas destacaram com mais força o conceito de educação física vinculado ao esporte e, em alguns casos, não conseguiram perceber sua importância enquanto disciplina escolar. Os dados mostraram que ainda são necessários ajustes para que a inclusão nas aulas de educação física seja de fato vantajosa para os alunos com deficiências / The aim of this study was to assess fitness aspects of 24 blind adolescents (12 from inclusive schools and 12 from a special school) and their perceptions about physical education classes. It was also analyzed the attitudes of ninety physical education teachers toward the inclusion of handicapped students in regular schools. About teachers? attitudes, it was verified that major concerns were insufficient knowledge of teachers and poor facilities in schools to adequately receive handicapped students. With regard to fitness tests, students from special schools presented better results and evolution in almost all assessed variables. About perceived acceptance and competence, students from special school again showed more positive results than their colleagues from inclusive schools, asserting to be more participative in classes and more accepted by their classmates and their teachers. At last, with regard to blind adolescents? concept about physical education, it was verified that those from special school had a concept more related with health, friendship and autonomy gain. By the other hand, the adolescents from inclusive schools detached strongly physical education concept entailed to sport and, in some cases, they didn\'t get to perceive its importance as a school discipline. Results showed that still some agreements are necessary for inclusion in physical education classes to be advantageous for handicapped students

Sistemas de Gerenciamento de Identidade Centrados no Usuário têm sido utilizados na Internet como meio de evitar o gerenciamento de múltiplas contas em sites e serviços na Web. Embora o uso de tais sistemas apresente benefícios, usuários podem ter sua privacidade prejudicada, uma vez que suas identidades tendem a ser conhecidas e controladas por uma entidade central. Dessa maneira, os acessos a serviços e o comportamento dos usuários tendem a ser facilmente rastreáveis em toda a rede. Por outro lado, do ponto de vista dos serviços, existem casos onde o conhecimento e a comprovação de informações do usuário é uma necessidade para o controle de acesso e provimento do serviço. Assim, o objetivo deste trabalho é propor uma solução de gerenciamento de identidades que proteja a privacidade e, ao mesmo tempo, possibilite a comprovação de atributos de identidade do usuário para um provedor de serviços no ambiente Web atual. Esta proposta inova dentre os trabalhos relacionados encontrados na literatura devido à sua adequação às necessidades e limitações existentes no ambiente típico da interação entre usuários e sites na Internet. A verificação do cumprimento dos objetivos de autenticação de atributos de identidade e privacidade do usuário é realizada por meio da análise formal do protocolo da solução. Ainda, com a aplicação de uma métrica, são analisados as condições e níveis de anonimato de um usuário no uso do sistema. / User-centric Identity Management Systems have been used on the Internet for avoiding the management of multiple users accounts in different sites and services on the Web. Although those systems can bring some benefits for its users, their privacy may be jeopardized since their identities are likely to be known and controlled by a central entity. This way, users behavior and their accesses to services are likely to be easily tracked on the network. On the other side, from the services point of view, there are occasions where the knowledge and verification of some users aspects and attributes are necessary for access control and service providing. Thereby, the goal of this work is to propose a solution for identity management that provides enhanced privacy for user and, at the same time, allows them to prove attributes of their identity to a service provider on the current Web environment on the Internet. This proposal innovates when compared to related works due to its suitability to the environment and its interactions between clients and sites on the Internet. The objectives related to the verification of identitys attributes and privacy concerns in this proposal are analyzed by formal methods. This work also presents an analysis on the conditions and levels of anonymity when users interact with the system based on a metric.

No description available.

abstract: Access to real-time situational information including the relative position and motion of surrounding objects is critical for safe and independent travel. Object or obstacle (OO) detection at a distance is primarily a task of the visual system due to the high resolution information the eyes are able to receive from afar. As a sensory organ in particular, the eyes have an unparalleled ability to adjust to varying degrees of light, color, and distance. Therefore, in the case of a non-visual traveler, someone who is blind or low vision, access to visual information is unattainable if it is positioned beyond the reach of the preferred mobility device or outside the path of travel. Although, the area of assistive technology in terms of electronic travel aids (ETA’s) has received considerable attention over the last two decades; surprisingly, the field has seen little work in the area focused on augmenting rather than replacing current non-visual travel techniques, methods, and tools. Consequently, this work describes the design of an intuitive tactile language and series of wearable tactile interfaces (the Haptic Chair, HaptWrap, and HapBack) to deliver real-time spatiotemporal data. The overall intuitiveness of the haptic mappings conveyed through the tactile interfaces are evaluated using a combination of absolute identification accuracy of a series of patterns and subjective feedback through post-experiment surveys. Two types of spatiotemporal representations are considered: static patterns representing object location at a single time instance, and dynamic patterns, added in the HaptWrap, which represent object movement over a time interval. Results support the viability of multi-dimensional haptics applied to the body to yield an intuitive understanding of dynamic interactions occurring around the navigator during travel. Lastly, it is important to point out that the guiding principle of this work centered on providing the navigator with spatial knowledge otherwise unattainable through current mobility techniques, methods, and tools, thus, providing the \emph{navigator} with the information necessary to make informed navigation decisions independently, at a distance. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2020

The central aortic blood pressure signal is an important source of information that contains cues about the cardiovascular system condition. Measuring this pulse wave clinically is burdensome as it can be only measured invasively with a catheter. As a result, many mathematical tools have been proposed in the past few decades to reconstruct the aortic pressure signal from the peripheral pressure signals that are usually easier to obtain noninvasively. At the distal level, the blood pressure signal is not directly useful since factors, such as length and stiffness of the arteries, play roles in changing the shape of the pressure signal significantly. In this thesis, multi-channel blind system identification techniques are proposed to estimate the central pressure waveform which vary in their accuracy and complex- ity. First, a simple linear method is applied by approximating the nonlinear arterial system as a linear time-invariant system and applying the cross-relation approach. Next, a more complicated nonlinear Wiener system is proposed to model the nonlinear arterial tree. Along with the channel’s coefficients, the nonlinear functions are estimated using cross-relation and kernel methods. Data-driven machine learning methods are tested to estimate the aortic pressure signals. In many cases, they suffer from underfitting problems. As a remedy, a hybrid machine learning and cross-relation approach is also proposed to add more robustness to the machine learning models. This hybrid approach is implemented by combining the cross-relation with any machine learning method, including deep learning approaches. The various methods are tested using pre-validated virtual databases. The results show that the linear method produces root mean squared errors between 3.40 mmHg and 6.24 mmHg depending on the cross-relation constraint and the equalization tech- nique. On the other hand, the root mean squared errors associated with the nonlinear methods are between 3.76 mmHg and 4.22 mmHg and hence more stable. For the hybrid machine learning and cross-relation approach, applying the cross-relation and the dictionary learning reduce the root mean squared errors up o 67% comparing with the pure machine learning models.

This study is about music teaching strategies for students with low vision, including blindness. Based on a two-case ethnographic design, this study focuses on understanding what decisions in terms of activities, lesson plans, and curricula, six participants from two different schools adopted for their students, as well as how these decisions relate to these students’ special needs and the context of these two schools. One of these school was located in Santiago, Chile, while the other in New York, USA. Data collection included observations and fieldnotes, interviews and informal conversations, artifact and document collections, and the use of a reflective journal. Findings encompass a variety of strategies recorded in several formal learning spaces such as instrumental private lessons, music theory lessons, instrumental ensemble rehearsals, choir rehearsal, accessible music technology lessons, braille lessons, general music lessons. These strategies, in turn, seemed to be highly conditioned by the students’ special need as well as the social, political, economic, and cultural contexts of the two schools observed.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第23314号 / 情博第750号 / 新制||情||128(附属図書館) / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 山本 章博, 教授 鹿島 久嗣, 教授 河原 達也 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM