Made available in DSpace on 2014-06-11T19:34:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-19Bitstream added on 2014-06-13T19:04:56Z : No. of bitstreams: 1 goncalves_vd_dr_guara.pdf: 2777682 bytes, checksum: 5d4369fe1e30d71b1e79eccb5580ba09 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho descreve o desenvolvimento de um sistema de análise de imagens de partículas de desgaste encontradas em óleos lubrificantes de equipamentos industriais. Para tanto, foi utilizado um sistema de aquisição de imagem para capturar imagens de amostras de óleo retidas em membranas de filtro e, também, desenvolvida uma metodologia analítica que faz a classificação quantitativa e qualitativa das partículas, relacionando-as ao modo de desgaste na qual foram geradas. Para a classificação quantitativa utilizou-se a norma ISO 4406 e para a qualitativa, a análise por meio de Redes Neurais Artificiais. O sistema aplicado consiste em uma câmera digital, um microscópio óptico monocular, um sistema de filtragem de óleo e dois programas computacionais desenvolvidos para realização da análise automatizada das imagens das partículas de desgaste obtidas. Foram utilizados óleos minerais de redutores de máquinas industriais no processo de obtenção de amostras. As partículas de desgaste foram analisadas pelo processo de microscopia óptica para obtenção da imagem da amostra relacionada ao desgaste. Os resultados obtidos mostraram que o sistema de análise desenvolvido realiza a classificação individual das partículas, através de Redes Neurais Artificiais, com uma eficiência de até 96%, além de analisar as múltiplas partículas contidas nas amostras, exibindo um relatório de acompanhamento e evolução do desgaste. Os programas computacionais desenvolvidos para essa análise possuem interface gráfica de fácil utilização. Eles podem ser amplamente utilizados no estudo e avaliação das partículas de desgaste obtidas de amostras de óleos industriais em empresas ou em universidades para fins educacionais. O sistema pode ser utilizado para análise de superfícies de metais obtidos pelo processo de metalografia ou na análise de imagens de microorganismos obtidas... / This paper describes the development of an image analysis system for wear particles found in industrial equipment lubricating oil. Hence, it was utilized an image acquisition system to capture image samples of the oil held in filter membranes. An analytical methodology was also developed to classify the particles quantitatively and qualitatively, relating them to the wear mode where they had been generated. The ISO 4406 standard was applied for quantitative classification and Artificial Neural Networks were used for qualitative classification analysis. The applied system consists of a digital camera, a monocular optical microscope, one oil filtering system and two software programs developed to perform the automated analysis of the acquired wear particles images. Mineral oils of gearbox industrial machines were used in the process of achieving the samples. The wear particles were analyzed by an optical microscopy system, to obtain the sample image related to the wear. The results showed that the analysis system that was developed classifies the individual particles through Artificial Neural Networks with 96% accuracy, in addition to analyzing the multiple particles contained in the samples and generating an evaluation report and wear evolution. The software programs developed for the analysis have a graphical interface easy to use. They can be used in the study and evaluation of the wear particles obtained from industrial oil samples in the companies or in the universities for educational purposes. The system can be applied to analyze the surface of metals acquired by metallographic processes or in the image analysis of microorganisms acquired from blood samples, opening a wide field of application within universities and researches.

Recentemente, com o rápido progresso da informática, a qual tem criado novos sistemas semi-automáticos ou mesmo completamente automáticos para avaliar os parâmetros metalográficos, tornou-se possível oferecer aos usuários da prática metalográfica, uma nova opção para determinar os parâmetros de interesse, cuja determinação em materiais metálicos é executada por vários métodos e utilizada extensivamente na prática metalográfica, pois estes parâmetros contribuem significativamente para a resistência mecânica dos aços ao carbono. Porém a escolha do melhor método a ser adotado é um assunto bastante discutido por vários autores. As nove amostras das chapas de aços ao carbono comum recozidas, com porcentagem de carbono variando de 0,05% a 0,56% apresentando estrutura ferrítica ou ferrítico-perlítica foram selecionadas, objetivando ao estudo de uma correlação entre os métodos tradicionais mais utilizados, como também o método que utiliza o sistema de análise de imagem digitalizada, que enfatiza a diferença dos níveis de cinza entre as fases presentes. Os atuais resultados dessa correlação, representam um dos primeiros trabalhos na área. Os resultados dos achados metalográficos,explorando na íntegra a particularidade de cada método, demonstram que o método de análise de imagem, relacionado aos métodos tradicionais, conduz a uma rápida e precisa obtenção dos parâmetros, com uma boa reprodutividade dos resultados. / The evaluation of the metallographic parameters in metallic materials has been carried out by many methods and they have been used extensively in the metallographic practice. However, the best method to be adopted has been a subject of many discussion. Nowadays, with the fast advance of computerisation, it has been possible to create semi-automatic or completely automatic systems for evaluation of these metallographic parameters, which are very important in determining the mechanical strength of carbon steels. In this work nine samples were removed from carbon steel plates with carbon content varying from 0,05 to 0,56 for evaluation of the correlation between the traditional methods, as well as with the method which use a digitised image analysis. This late method emphasise to the difference on the grey levels of the phases present. The results from this work are one of the first in this area, and they exploited the particularity of each method. Also, they demonstrated that the image analysis method, when compared with the traditional ones, gives a rapid and precise evaluation of the metallographic parameters, with a very good results reproducibility.

Design and analysis of computer experiments is an area focusing on efficient data collection (e.g., space-filling designs), surrogate modeling (e.g., Gaussian process models), and uncertainty quantification. Survival analysis focuses on modeling the period of time until a certain event happens. Data collection, prediction, and uncertainty quantification are also fundamental in survival models. In this dissertation, the proposed methods are motivated by a wide range of real world applications, including high-performance computing (HPC) variability data, jet engine reliability data, Titan GPU lifetime data, and pine tree survival data. This dissertation is to explore interfaces on computer experiments and survival analysis with the above applications. Chapter 1 provides a general introduction to computer experiments and survival analysis. Chapter 2 focuses on the HPC variability management application. We investigate the applicability of space-filling designs and statistical surrogates in the HPC variability management setting, in terms of design efficiency, prediction accuracy, and scalability. A comprehensive comparison of the design strategies and predictive methods is conducted to study the combinations' performance in prediction accuracy. Chapter 3 focuses on the reliability prediction application. With the availability of multi-channel sensor data, a single degradation index is needed to be compatible with most existing models. We propose a flexible framework with multi-sensory data to model the nonlinear relationship between sensors and the degradation process. We also involve the automatic variable selection to exclude sensors that have no effect on the underlying degradation process. Chapter 4 investigates inference approaches for spatial survival analysis under the Bayesian framework. The Markov chain Monte Carlo (MCMC) approaches and variational inferences performance are studied for two survival models, the cumulative exposure model and the proportional hazard (PH) model. The Titan GPU data and pine tree survival data are used to illustrate the capability of variational inference on spatial survival models. Chapter 5 provides some general conclusions. / Doctor of Philosophy / This dissertation focus on three projects related to computer experiments and survival analysis. Design and analysis of the computer experiment is an area focusing on efficient data collection, building predictive models, and uncertainty quantification. Survival analysis focuses on modeling the period of time until a certain event happens. Data collection, prediction, and uncertainty quantification are also fundamental in survival models. Thus, this dissertation aims to explore interfaces between computer experiments and survival analysis with real world applications. High performance computing systems aggregate a large number of computers to achieve high computing speed. The first project investigates the applicability of space-filling designs and statistical predictive models in the HPC variability management setting, in terms of design efficiency, prediction accuracy, and scalability. A comprehensive comparison of the design strategies and predictive methods is conducted to study the combinations' performance in prediction accuracy. The second project focuses on building a degradation index that describes the product's underlying degradation process. With the availability of multi-channel sensor data, a single degradation index is needed to be compatible with most existing models. We propose a flexible framework with multi-sensory data to model the nonlinear relationship between sensors and the degradation process. We also involve the automatic variable selection to exclude sensors that have no effect on the underlying degradation process. The spatial survival data are often observed when the survival data are collected over a spatial region. The third project studies inference approaches for spatial survival analysis under the Bayesian framework. The commonly used inference method, Markov chain Monte Carlo (MCMC) approach and the approximate inference approach, variational inference's performance are studied for two survival models. The Titan GPU data and pine tree survival data are used to illustrate the capability of variational inference on spatial survival models.

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Thesis (MScPhysio)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The aim of this study was to improve the measurement of postural dynamism in the sitting position using a three-dimensional (3D) motion analysis system. The primary objective was to describe pilot data for postural dynamism of the cervical and thoracic spines while working at a desktop computer. The secondary objective was to refine the process of posture measurement and analysis by decreasing data processing time. Certain factors in 3D motion analysis can lead to an increase in gaps in data collected during trial capture, which in turn will lead to a longer time of data processing. In the first phase of this study, a number of such factors were identified and altered. A series of pilot studies was performed to test the improvement of data processing time when altering these factors. In the first two pilot studies, camera and tripod positionings were explored and refined, workstation layout and anatomical landmark marker placement were investigated, and optimal capture frequency was established. In both these pilot studies, outcomes were established by means of trial and error by experimenting with a variety of different options for the different outcomes. In the third pilot study, computer software which provides computer tasks for the participant during primary trial capture was tested. Two independent computer users performed all the activities as per software, after which they were required to give oral feedback and suggestions on improvement in terms of user friendliness. The objective of the fourth and final pilot study was to include all of the outcomes from the preceeding pilot studies and attempt a trial run of the actual data collection process. A study participant with no affiliation to the research project was used and a complete trial run was performed after which the measurement process was deemed feasible. In the primary study, 18 student volunteers completed a sequence of computer tasks, including keyboard, mouse and reading activities. Prior to data capture, full range of motion of the thoracic and cervical spines were measured in three dimensions for every participant. Data capture took place for the full duration of performance of all computer activities. Outcome parameters for postural dynamism included true range of motion (degrees), proportional range of motion (percentage) and motion frequency (movement per minute) in all three planes of motion of the cervical and thoracic spines. Typing tasks were associated with biggest movement ranges and motion frequencies. Mouse activity was associated with the most stationary posture, exhibiting the least frequent movement as well as the smallest ranges of motion. The results from this study allow us to better understand the dynamic nature of posture, as well as postural dynamism associated with different computer tasks. This study provides a baseline for future research of 3D motion analysis of the sitting posture. It also marks the need for further research regarding ergonomics, use and potential alternatives in the computer workstation and input devices. / AFRIKAANSE OPSOMMING: Hierdie studie het ten doel gehad om die meting van posturale dinamisme in die sitposisie te verbeter deur middel van „n drie-dimensionele (3D) bewegingsanalisesisteem. Die primêre doelwit was om loodsdata te beskryf vir posturale dinamisme van die servikale en torakale werwelkolomme terwyl op „n rekenaar gewerk word. Die sekondêre doelwit was om die proses van postuurmeting en analise te verfyn deur die dataprosesseringstyd te verminder. Sekere faktore van 3D bewegingsanalise kan „n vermeerdering van gapings in ingesamelde data tot gevolg hê, wat weer kan lei na „n verlengde tydperiode van dataprosessering. In die eerste fase van hierdie studie is sulke faktore identifiseer en aangepas. „n Reeks loodsstudies is uitgevoer om die verbetering van dataprosesseringstyd te toets namate aanpassings aan hierdie faktore gemaak is. Tydens die eerste twee loodsstudies is verskillende kamera en driepoot posisionering ondersoek en verfyn, werkstasie uitleg en anatomiese baken merker plasing is ondersoek en die optimale dataversamelingsfrekwensie is vasgestel. In beide hierdie loodsstudies is die uitkomste vasgestel op grond van toets- en fouteer deur te eksperimenteer met „n verskeidenheid opsies soos van toepassing op die betrokke uitkomste. Tydens die derde loodsstudie is rekenaarsagteware getoets wat die rekenaaraktiwiteit vir die studiedeelnemers verskaf het tydens primêre data-insameling. Twee onafhanklike persone het al die aktiwiteite volgens die sagteware voltooi en het verbale terugvoer en aanbevelings gegee oor hoe om die program te verbeter. Die vierdie en finale loodsstudie het gepoog om al die uitkomste van die eerste drie loodsstudies in te sluit en „n toetsmeting te doen van die ware dataversamelingsproses. „n Onafhanklike studiedeelnemer met geen affiliasie tot die navorsingsprojek nie het „n toetslopie van die hele versamelingsproses gedoen en die metingsproses is haalbaar verklaar. Tydens die primêre studie het 18 student-vrywilligers „n reeks rekenaartake gedoen (insluitend sleutelbord en muisaktiwiteite sowel as „n leesopdrag). Voor die aanvang van dataversameling is die volle bewegingsomvange van die torakale en servikale werwelkolomme van elke deelnemer gemeet. Dataversameling is vir die volle durasie van die uitvoer van rekenaaraktiwiteite gedoen. Uitkomsparameters vir posturale dinamisme het die volgende ingesluit: Omvang van beweging (grade), proporsionele omvang van beweging (persentasie) en bewegingsfrekwensie (bewegings per minuut) in al drie bewegingsvlakke van die servikale en torakale werwelkolomme. Sleutelbord-aktiwiteite is geässosieer met die grootste bewegingsomvange en die meeste bewegingsfrekwensie. Muisaktiwiteit is geässosieer met die mees stasionêre postuur en het die heel minste gereelde beweging getoon in die algemeen. Die resultate van hierdie studie help om die dinamise natuur van postuur beter te verstaan, sowel as posturale dinamisme wat met verskillende rekenaartake verbind word. Die studie bied „n basislyn vir die toekomstige navorsings wat posturale dinamisme met verskillende rekenaartake meet. Dit merk ook die behoefte aan verdere navorsing aangaande ergonomika, gebruik en alternatiewe tot rekenaarwerkstasie en –toerusting.

Developing high-end aerospace components is a complex and highly competitive business. Hence methods for decreasing lead-time, while still providing the same quality and at a lower cost, has to be developed. This thesis is conducted at Research & Technology - GKN Aerospace in Trollhättan Sweden. A multidisciplinary analysis system known internally as Engineering Workbench, forms the base for implementation of the methods and tools developed in this thesis work. The system applies set-based engineering approach to develop new components. The evaluation of the design space is performed through parametric studies to find relations between the design parameters and performance metrics of the design. The engineering workbench allows GKN to define and evaluate a large design space within a limited timeframe. This thesis will look to improve the current producibility assessment system within the EWB by increasing the robustness and flexibility of the system. This is done by re-designing the producibility analysis part system and into a modular knowledge-based system that implements various techniques to increase the robustness and flexibility of the system. The re-designed system is automated, flexible and robust and is able to perform user defined weld assessments on a various designs and provides GKN with weld producibility data.

An experimental data management system has been designed, developed, and implemented in this dissertation. The system satisfies the requirements specifications of the Department of Curriculum and Instruction in the School of Education. The university in this study has installed some learning management systems and assessment systems, such as Banner®, Canvas®, TracDat®, and Taskstream® (university’s name is omitted for anonymity purposes). These systems individually do not perform the necessary data analysis and data management to generate appropriate reports. The system developed in this study can generate more metrics and quantitative measures for reporting purposes within a shorter time. These metrics provide credible evidence for accreditation. Leadership is concerned with improving the effectiveness, efficiency, accountability, and performance of educational programs. The continuity, sustainability, and financial support of programs depend on demonstrating the evidence that they are effective and efficient, that they meet their objectives, and that they contribute to the mission and the vision of the educational institution. Leadership has to employ all means at its disposal in order to collect such evidence. The data management system provides comprehensive data analysis that can be utilized as evidence by the leadership to accomplish its goals. The pilot system developed in this research is web-based and platform independent. It leverages the power of Java® at the front-endand combines the reliability and stability of Oracle® as the back-end database. It has been tested on-site by some members of the departmental faculty and one administrator from the Dean’s Office in the School of Education. This research is a mixed methods study with quasi-experimental treatment. It is a single case experimental study. There is no control group. The sample chosen is a convenient sample. The results of this study indicate that the system is highly usable for assessment work. The data analysis results generated by the system are also actionable. These results assist by identifying gaps in student performance and in curriculum and instruction practices. In the future, the system developed in this dissertation can be extended to other departments in the School of Education. Some implications are provided in the concluding chapter of this dissertation.

La quantification des métaux dans les milieux aquatiques est un enjeu majeur, au vu de leur toxicité élevée et de leurs nombreuses sources d’émission dans l’environnement. Dans cette optique, le développement de systèmes d’analyse en ligne portables et à bas coût va permettre de réaliser des contrôles répétés et automatisés sur site. Trois métaux ont été ciblés dans cette étude : le plomb, le cadmium et le mercure. Pour développer ces systèmes, l’impression 3D a été utilisée pour réduire les coûts de fabrication et permettre la conception de modules sur mesure. Trois systèmes ont été développés, selon la méthodologie suivante : dans un premier temps, l’échantillon va être photo-oxydé pour extraire les métaux de la matrice organique et minérale, puis les métaux ciblés vont être ensuite préconcentrés sur phase solide, élués et détectés en spectroscopie UV-Visible ou en fluorescence. Les choix de la phase solide, de l’éluant et du réactif de détection vont ainsi être déterminants pour la caractérisation sélective et sensible de chaque métal. Un premier système pour l'analyse du plomb a été développé, et se compose de trois modules imprimés en 3D, accueillant une colonne de résine, un mélangeur, et une cellule de détection optique. Un second système, sous la forme d’un lab-on-valve, permet la quantification du plomb et du cadmium. Enfin le troisième système, portant sur le mercure, intègre une pièce imprimée en 3D dont la surface a été greffée avec une molécule (dithizone carboxylate) permettant l'extraction sélective du mercure du milieu. Ces systèmes conduisent ainsi à de nouvelles perspectives pour le développement de systèmes en flux plus complexes imprimés en 3D. / Metals determination in aqueous samples is a major challenge nowadays, in the light of their high toxicity and their numerous emission sources into the environment. In this context, the development of on-line and low-cost analytical systems allows to carry out automated on-site measurements. Three metals (lead, cadmium and mercury) have been targeted in this study. 3D printing has been used in this study to reduce fabrication costs and to allow a tailor-made conception of the units. The developed flow systems in this study are based on the same analytical methodology: first, the sample is photo-oxidized to extract targeted metals from organic and mineral matrix of the sample. Then, metals are preconcentrated on a solid phase, then eluted and detected by UV-Visible or fluorescence spectroscopy. The choices of preconcentration solid phases, eluents, and detection reagents are decisive for the selective and sensitive characterisation of each metal. The first developed system concerns lead analysis, and consists of three 3D printed units, which contain a resin column, a mixing coil, and a spectroscopic flow-cell. The second system for lead and cadmium determination contains a 3D printed lab-on-valve with eight ports, two resin columns, and a mixing coil with baffles. Finally, the third system includes a 3D printed unit whose surface has been modified by grafting a molecule with high affinity for mercury (dithizone carboxylate). This 3D printed unit provides a selective extraction of mercury after modification of its surface. The systems thus developed allow to explore the possibilities of 3D printing for the development of more complex flow systems.

Objetivo. Avaliar a aplicação da Política Estadual de Recursos Hídricos de São Paulo, Lei Estadual 7.663, de 30 de dezembro de 1991, na Unidade de Gerenciamento de Recursos Hídricos - UGRHI 5, entre 1994 e 2003, com vistas a contribuir para aperfeiçoamentos e reformulações do Sistema Integrado de Gerenciamento de Recursos Hídricos - SIGRH, bem como propor um método de avaliação de políticas de recursos hídricos. Material e métodos. Foi realizado levantamento de informações em documentos e por meio de entrevistas, que por sua vez subsidiaram a elaboração de discursos do sujeito coletivo de atores participantes do SIGRH. Resultados e discussão. Entre outras questões, permitiu-se entender o processo de gerenciamento de recursos hídricos, bem como identificar interfaces para a adequada aplicação da Lei Estadual 7.663/91, nesta Região. Conclusões. Embora denote-se ausência de implementação da cobrança pelo uso dos recursos hídricos e da elaboração anual de relatórios de situação e quadrienal de planos de bacias, considerados fundamentais no contexto da Região, os demais aspectos avaliados, de maneira geral, têm atendido ao estabelecido na Lei Estadual 7.663/91. As recomendações se referem à implementação da cobrança como elemento de racionalização do consumo de água, sistematização de informações, desenvolvimento de articulação entre órgãos e entidades, planejamento da demanda em conjunto com a oferta de recursos hídricos, planejamento territorial, aumento da participação popular e mudança de comportamento. Por fim, o método utilizado foi estruturado na forma de um protótipo, que poderá subsidiar avaliações de políticas de recursos hídricos em outras situações e regiões brasileiras. / Objective. São Paulo State Water Resources Policy’s assessment at Hydrographic Region 5, between the years 1994 and 2003, in order to contribute for enhancing and improving São Paulo Water Resources Management System, as well as to propose a method for water resources policies assessment. Material and methods. The research was based on documental analysis and interviews. The interviews’ analysis was developed through a method called discourse of the collective subject. Results and discussion. Among other subjects, it was possible to understand the water resources management, as well as to identify interfaces for a better application of São Paulo State 7.663/91 Law. Conclusion. Eventhough there is no water use charge established yet, and one can identify the lack of some reports and plans regarding the water resources of the region, most of the other water policy aspects are being applied as defined by the São Paulo State 7663/91 Law. The recommendations regard to the implementation of water use charge as an instrument to reduce water use, improvement of water resources information, development of closer relationship among entities, elaboration of a plan considering water resources demand and capacity, land planning, improvement of community participation on water resources system and behavior changing. The used method was structured as a prototype which can be used for other water resources policies assessment, and not only in São Paulo State but also in other Brazilian region.

Objetivo. Avaliar a aplicação da Política Estadual de Recursos Hídricos de São Paulo, Lei Estadual 7.663, de 30 de dezembro de 1991, na Unidade de Gerenciamento de Recursos Hídricos - UGRHI 5, entre 1994 e 2003, com vistas a contribuir para aperfeiçoamentos e reformulações do Sistema Integrado de Gerenciamento de Recursos Hídricos - SIGRH, bem como propor um método de avaliação de políticas de recursos hídricos. Material e métodos. Foi realizado levantamento de informações em documentos e por meio de entrevistas, que por sua vez subsidiaram a elaboração de discursos do sujeito coletivo de atores participantes do SIGRH. Resultados e discussão. Entre outras questões, permitiu-se entender o processo de gerenciamento de recursos hídricos, bem como identificar interfaces para a adequada aplicação da Lei Estadual 7.663/91, nesta Região. Conclusões. Embora denote-se ausência de implementação da cobrança pelo uso dos recursos hídricos e da elaboração anual de relatórios de situação e quadrienal de planos de bacias, considerados fundamentais no contexto da Região, os demais aspectos avaliados, de maneira geral, têm atendido ao estabelecido na Lei Estadual 7.663/91. As recomendações se referem à implementação da cobrança como elemento de racionalização do consumo de água, sistematização de informações, desenvolvimento de articulação entre órgãos e entidades, planejamento da demanda em conjunto com a oferta de recursos hídricos, planejamento territorial, aumento da participação popular e mudança de comportamento. Por fim, o método utilizado foi estruturado na forma de um protótipo, que poderá subsidiar avaliações de políticas de recursos hídricos em outras situações e regiões brasileiras. / Objective. São Paulo State Water Resources Policy’s assessment at Hydrographic Region 5, between the years 1994 and 2003, in order to contribute for enhancing and improving São Paulo Water Resources Management System, as well as to propose a method for water resources policies assessment. Material and methods. The research was based on documental analysis and interviews. The interviews’ analysis was developed through a method called discourse of the collective subject. Results and discussion. Among other subjects, it was possible to understand the water resources management, as well as to identify interfaces for a better application of São Paulo State 7.663/91 Law. Conclusion. Eventhough there is no water use charge established yet, and one can identify the lack of some reports and plans regarding the water resources of the region, most of the other water policy aspects are being applied as defined by the São Paulo State 7663/91 Law. The recommendations regard to the implementation of water use charge as an instrument to reduce water use, improvement of water resources information, development of closer relationship among entities, elaboration of a plan considering water resources demand and capacity, land planning, improvement of community participation on water resources system and behavior changing. The used method was structured as a prototype which can be used for other water resources policies assessment, and not only in São Paulo State but also in other Brazilian region.