AA análise multivariada e um conjunto de técnicas que são adequadas para situações onde varias variáveis correlacionadas estão envolvidas. Dentre essas técnicas temos as componentes principais e a analise fatorial. A técnica dos componentes principais reduz a dimensão de uma matriz de dados originais através de combinações lineares facilitando a interpretação desses dados e a analise fatorial que e o nome dado a uma classe de métodos estatísticos paramétricos (e não paramétricos) multivariados que correspondem a um grande numero de métodos e técnicas que utilizam simultaneamente todas as variáveis do conjunto na interpretação do inter-relacionamento das variáveis observadas (COSTA, 2006). O objetivo da analise fatorial e descrever as relações de covariância entre algumas variáveis em algum termo subjacente, mas não observável, de quantidades aleatórias chamadas fatores (JOHNSON e WICHERN, 1998). Biplot e um gráfico estático, desenvolvido por Gabriel (1971), que representa no mesmo gráfico as variáveis o as observações com o intuito de demonstrar graficamente as relações existentes entre variáveis, entre observações e entre variáveis e observações. O presente trabalho tem como objetivo inserir a metodologia de analise biplot tridimensional na técnica de analise fatorial multivariada. Foi usado o software SAS para a realização da analise fatorial e a construção do gráfico biplot e um conjunto de dados para a aplicação do mesmo. O estudo mostra que o gráfico Biplot e um método de analise multivariada de suma importância quando inserido na analise fatorial facilitando e complementando a interpretação dos resultados / Multivariate analysis is a set of techniques that are appropriate for situations where several correlated variables are involved. Among these techniques have the principal components and factor analysis. The technique of principal components reduces the size of an array of original data through linear combinations facilitating the interpretation of these data and factor analysis that is the name given to a class of parametric statistical methods (non parametric) multivariate corresponding to a large number of methods and techniques that use simultaneously all the variables set in the interpretation of the interrelationship of the observed variables (COSTA, 2006). The goal of factor analysis is to describe the covariance relationships between variables in any term underlying, but unobservable, random quantities called factors (Johnson and Wichern, 1998). Biplot is a statistical graph, developed by Gabriel (1971), which represents the in same graph the variables to the observations in order to demonstrate graphically the relationship between variables, between observations and between variables and observations. This paper aims to insert the biplot analysis methodology in three-dimensional technique of multivariate factor analysis. Was used SAS software to perform the factor analysis and construction of the biplot graph and a set of data for the application. The study shows that the graph Biplot is a method of analysis of the utmost importance when inserted in the factor analysis, facilitating and complementing the interpretation of results.

Orientador: Franco Giuseppe Dedini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-24T21:14:00Z (GMT). No. of bitstreams: 1 NacerColmenero_Alberto_M.pdf: 9387560 bytes, checksum: 8ce3464ab75b288b4b8a9e8615aa96da (MD5) Previous issue date: 1999 / Resumo: Neste trabalho apresenta-se um estudo sobre os aspectos básicos relacionados com os ensaios acelerados utilizados na industria, são apresentados alguns conceitos fundamentais para o melhor entendimento da temática, as relações estresse x vida e distribuições de vida mais utilizadas. Do estudo realizado, foi escolhida uma metodologia para analisar os ensaios acelerados de vida, diferente à que é empregada em muitas industrias atualmente, baseada em um tipo de planejamento aleatorizado por níveis. Por último é apresentado um programa para o processamento dos dados provenientes de ensaios acelerados com estresse constante e modo de falha simples, para dados completos, e com censura a direita ou múltipla, utilizando a distribuição de Weibull, Log-normal e Normal, combinadas com os modelos mais utilizados (Arrhenius e Lei da Potência Inversa), o programa permite o processamento dos dados dos ensaios acelerados por dois métodos, Mínimos Quadrados e Máxima Verossimilhança, o primeiro oferece os estimados iniciais para aplicar o método de Máxima Verossimilhança, e assim assegurar a convergência do método de Newton-Raphson para todos os casos. Outras saídas do programa são; gráficos de residuais, de probabilidades vs. tempo, estresse vs. percentuais, etc. No programa são utilizados testes estatísticos para a validação dos ensaios, dando a possibilidade de utilizar diferentes níveis de confiança para calcular os intervalos de confiança dos parâmetros utilizados / Abstract: This work presents a study on the basie aspects related with the accelerated tests used in the industry, some fundamental concepts are presented for the best understanding of the thematic, the relationships stress x life and the more applied life distributions. A methodology was chosen to analyze the accelerated life tests, different from that commonly applied now in a lot of industries, based on a type of ramdomic planning by levels. Last a software is presented for the processing of the accelerated tests data with constant stress and simple failure mode, for complete data, and with right or multiple censored tests, using the Weibull, Log-normal and Normal distributions, combined with the most used models (Arrhenius model and the Inverse Power Law), the program allows the processing of the accelerated tests data by two methods, Minimum Square and Maximum Likelihood, the first offers the evaluated initial values to apply the method of Maximum Likelihood, and in this way to assure the convergence of the method of Newton-Raphson for alI the cases. Other outputs of the software are; graphs of the residual, probabilities vs. time, stress vs. percentile, ete. In the program, statistical tests are used for the validation of the tests, giving the possibility to use different confidence levels to calculate the confidence intervals of the parameters of interest / Mestrado / Projeto Mecanico / Mestre em Engenharia Mecânica

Dans une optique d'allègement, les alliages d'aluminium de fonderie représentent une excellente solution technique. Ainsi, pour les culasses automobiles, les alliages d'aluminium Al-Si-Cu (Aluminium-Silicium-Cuivre) sont souvent choisis pour leurs performances mécaniques ainsi que leur bonne coulabilité. L'objectif de cette étude est d'améliorer la compréhension des mécanismes en fatigue oligocyclique pour définir un critère de fatigue adapté. Cet objectif est réalisé en combinant des essais (en fatigue oligocyclique à température ambiante et élevée), de nombreuses observations (microscopie à balayage électronique, microtomographie 3D rayons-X de laboratoire, suivi de fissure) et des simulations (génération de population de défauts et calculs éléments finis). À l'aide d'outils spécialement développés, la population de défauts (défauts de fonderie) est analysée en détails : la taille de défaut est modélisée par une distribution de Pareto généralisée et leurs positions par un processus ponctuel de type agrégé (démontrant que les défauts ne sont pas spatialement distribués de manière totalement aléatoire). Les processus ponctuels marqués permettent de montrer que tailles et positions de défauts ne sont pas corrélées. En utilisant ces informations statistiques, il est démontré que seuls les défauts proches de la surface sont critiques pour la fatigue oligocyclique. Un critère de fatigue basé sur l'énergie de déformation est utilisé pour prévoir la durée de vie en fatigue. Par la suite, un modèle de propagation de fissure permet de prendre en compte la taille de défaut dans la prévision de la durée de vie. Combiné à la statistique des défauts, ce modèle permet d'estimer la dispersion des essais. En dernier lieu, des essais et des simulations sur éprouvettes entaillées montrent que l'étude de la population de défauts est d'autant plus critique que le volume fortement sollicité mécaniquement devient plus faible. / In a search for lightweight materials, cast aluminium alloys have become an efficient solution for the automotive industry. For cylinder heads, cast aluminium alloys (Aluminium-Silicon-Copper based) are often chosen for their mechanical performances combined with their good casting abilities. This study aims at better understanding the damage mechanisms of Low-Cycle Fatigue (LCF) to help define a suitable design criterion. This is achieved by combining experiments (LCF tests at ambient and high temperature), various observations (Scanning electron microscopy, laboratory 3D X-ray microtomography, crack propagation monitoring) and numerical techniques (Finite element method simulations and defect population generation). Specifically designed statistical tools allow clearly identifying the defect (casting defects) population: the defect size can be modelled by a generalized Pareto distribution and their positions by a clustered point process (thus showing the defect locations are not completely random). Using marked point processes, it is also shown that defect size and defect position are uncorrelated. Using this statistical information and by systematic observations, it is proven that only defects close to the surface are critical for the fatigue life. The different interactions between cracks and defects are also studied, especially with respect to temperature. A strain energy based fatigue criterion is introduced and allows estimating the fatigue life. Then, a crack propagation model provides a mean of taking the defect size into account, which combined with the statistics of defects, gives an estimate of the fatigue life dispersion. Finally, notched specimens tests and simulations show the study of the defect population is even more critical as the highly loaded volume becomes smaller.

The work presented in this thesis concerns one of the key enabling techniques related to cognitive radio functionalities which is spectrum sensing as well as cooperative spectrum sensing. As cooperative spectrum sensing (CSS) approaches are commonly used for combating fading and improving detection performance, their performances using different combining rules have been analyzed. Due to the low implementation complexity, Goodness of Fit based spectrum sensing has been studied for cognitive radio applications. Motivated by its nice features of local sensing, a distributed consensus spectrum sensing for CR, has been presented, integrating a Goodness of Fit based spectrum sensing scheme. / Le travail présenté dans cette thèse concerne l'une des techniques clés dans les fonctionnalités de la radio cognitive qui est la détection du spectre ainsi que la détection coopérative du spectre. La détection coopérative est couramment utilisée pour la lutte contre l’évanouissement du canal à fin d'améliorer les performances de la détection. Les performances de la détection coopérative en utilisant différentes règles de fusion ont été analysées. En raison sa simplicité, la détection du spectre par les testes d’adéquation a été étudiée pour les applications de la radio cognitive. Motivé par la caractéristique d’être indépendant de bruit, ces testes d’adéquation ont été utilisés pour la détection locale, pour la détection coopérative distribuée. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Les difficultés majeures rencontrées en production des pièces mécaniques métalliques sont dues aux conditions de chargements extrêmes appliqués lors de la mise en forme ainsi qu'au problème de l'usure prématurée des outils de coupe de coupe. Dans ce cadre, les travaux de thèse sont centrés sur la mise en évidence et la compréhension des mécanismes physiques mis en jeu lors de l'usure des outils de coupe depuis l'échelle de la microstructure jusqu'à celle du système usinant, en passant par l'échelle de la pointe de l'outil (échelle mésoscopique). A cet effet, Un modèle analytique permettant de décrire l'usure par abrasion et de prédire la durée de vie des outils a été développé sur la base d'une approche statistique rendant compte de l'hétérogénéité des particules pouvant être à l'origine de la dégradation de l'outil. La prise en compte de la nature du contact collant-glissant et de l'effet du coefficient de frottement via des résultats de la littérature couplés au modèle proposé ont permis de mettre en évidence l'influence des paramètres opératoires de la coupe des métaux sur le volume d'usure enlevé par abrasion. A la suite ce modèle a été confronté à des résultats expérimentaux préalablement réalisé dans le cadre de la coupe orthogonale. En parallèle une analyse inclusionnaire est réalisée pour l'identification et la quantification des inclusions non métallique jugées responsable de l'usure par abrasion. Les résultats obtenue via des observations MEB et microscopique ainsi que des traitements d'images a permis d'alimenter en données le modèle prédictif / Tool wear and tool failure are critical problems in the industrial manufacturing field since they affect the quality of the machined workpiece (unexpected surface finish or dimensional tolerance) and raise the production cost. Improving our knowledge of wear mechanisms and capabilities of wear prediction are therefore of great importance in machining. The three main wear modes usually identified at the tool/chip and the tool/workpiece interfaces are abrasion, adhesion and diffusion. Besides the fact that understanding mechanisms that govern these wear mechanisms are still incomplete, the experimental analysis is very difficult because friction interface features (such as temperature, pressure, particles embedded in the contact …) are not easily measurable. The objective of this research work is to understand the physical mechanisms governing the tool wear by taking into account the sensibilities to scale going from the microscopic scale (microstructure scale) to the macroscopic scale (scale of the manufacturing operation) passing by the mesoscopic scale (tool tip scale). For this purpose, an analytic wear model was developed to describe the abrasive wear and to predict the cutting tool life. The proposed model is based on a tribological approach including a statistical description of the distribution of particles seen as non-metallic inclusions. The latter are assumed embedded at the interface of contact and having a conical shape characterized by two main parameters in the present approach: the corresponding size and apex angle. The volume of the removed material per unit time is chosen in this study as the main parameter to describe the abrasive wear mode. Coupled with literature results, the developed model is able to take into account the nature of the sticking-sliding contact and the effect of the friction coefficient on the rake face of the cutting tool. In order to identify all the material's parameters of the predictive model, a study of non-metallic inclusion considered responsible of the abrasive wear was performed on the 42CD4 steel. The determination of inclusion type and inclusion morphology was assessed qualitatively and quantitatively through microscopic and MEB observations as well as image processing. Finally, the volume removed by abrasion given by the model was compared to the experimental results previously achieved under orthogonal cutting.

Master of Science / Department of Statistics / Shie-Shien Yang / In fitting linear models, R[superscript]2 statistic has been wildly used as one of the measures to assess the goodness-of-fit and prediction power of the model. Unlike fixed linear models, at this time there is no single universally accepted measure for assessing goodness-of-fit and prediction power of a linear mixed model. In this report, we reviewed seven different approaches proposed to define a measure analogous to the usual R[superscript]2 statistic for assessing mixed models. One of seven statistics,Rc, has both conditional and marginal versions. Association mapping is an efficient way to link the genotype data with the phenotype diversity. When applying the R[superscript]2 statistic to the association mapping application, it can determine how well genetic polymorphisms, which are the explanatory variables in the mixed models, explain the phenotypic variation, which is the dependent variation. A linear mixed model method recently has been developed to control the spurious associations due to population structure and relative kinship among individuals of an association mapping. We assess seven definitions of R[superscript]2 statistic for the linear mixed model using data from two empirical association mapping samples: a sample with 277 diverse maize inbred lines and a global sample of 95 Arabidopsis thaliana accessions using the new method. R[superscript]2[subscript]LR statistic derived from the log-likelihood principle follows all the criterions of R[superscript]2 statistic and can be used to understand the overlap between population structure and relative kinship in controlling for sample relatedness. From our results,R[superscript]2[subscript]LR statistic is an appropriate R[superscript]2 statistic for comparing models with different fixed and random variables. Therefore, we recommend using RLR statistic for linear mixed models in association mapping.

Orientador: Ademir Petenate / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-07T20:52:25Z (GMT). No. of bitstreams: 1 Rascop_SilvanaBorges_M.pdf: 3322702 bytes, checksum: e12f841b84d759a99603bf799e2fdf64 (MD5) Previous issue date: 2006 / Resumo: O objetivo deste estudo foi aplicar a utilização o ¿Modelo de Melhoria¿, à gestão de controle em processo, visando a obtenção de qualidade no produto terminado e, posteriormente, implantá-lo em outras linhas de produção. O trabalho foi realizado no setor de revisão de produto final de uma indústria farmacêutica, na atividade de controle em processo. Utilizou-se o Modelo de Melhoria na determinação dos pontos críticos a serem trabalhados e as Normas de Amostragem por Atributos da ABNT para a determinação dos planos de amostragem. O estudo envolveu a avaliação de unidades do produto que já haviam passado pela revisão final e a determinação de itens com defeitos que não tinham sido separados pelo processo de revisão 100% caracterizando, assim, como falha de revisão. A reestruturação do Controle em Processo e o treinamento contínuo dos envolvidos propiciaram a diminuição do número de falhas ao longo do tempo, obtendo-se, com isto, melhoria de qualidade do produto terminado / Abstract: The objective of this study was to show that the use of the ¿Improvement Guide¿ methodology to obtain quality in products. The Improvement Guide Methodology was employed to determine the critical factors to be addressed and the ¿Sampling Rules¿ by attributes in acordance to ABNT (Brazilian Association of Technical Rules) was employed to determine the sampling plans. The study comprised the evaluation of samples that had already gone through the final revision process, thus bringing out defective items that had not been detected by the process, therefore being classified as 100% revision failure. By restructuring the process control and by creating an awareness of the employees envolved in the process, failures decreased through time and the problems were corrected, therefore leading toan improvement in the quality of the products / Mestrado / Gestão da Qualidade Total / Mestre Profissional em Engenharia Mecanica

Bakgrund: Depression är en av de vanligaste psykiska sjukdomarna idag och att det är i lika grad stigmatiserat. Stigma kan kopplas till okunnighet om psykisk ohälsa. Detta gör det nästintill omöjligt för individer som lider av psykisk ohälsa, såsom depression, att kunna vara en del av samhället och yttra sina känslor utan att motta negativitet relaterat till sin sjukdom. Som ett tillägg till detta är individerna i fråga oftast ensamma, dvs de föredrar isolering än sällskapet av de som stigmatiserar dem. Detta i sin tur ger upphov till känslor av oro och hopplöshet, hämmad återhämtning och även vägran att söka hjälp och behandling. Syfte: Syftet är att undersöka hur upplevelser av stigmatisering kommer till uttryck i blogginlägg bland unga vuxna med depression. Metod: En kvalitativ metod med hjälp av textanalys utfördes. Åtta blogginlägg sammanlagt användes för att komma fram till ett resultat. Blogginlägg granskades efter relevans av vårt syfte och studie. Resultat: Tre teman uppkom under studiens gång. Dessa är: ”Rädslan att prata om sin diagnos”, ”Depression är ett skämt” och ”Stigma från professionella”. Konklusion: Individer som upplever stigmatisering från samhället som en följd av sin psykiska sjukdom upplever ovilja till återhämtning, känslor av förtvivlan, värdelöshet och illamående som kan leda till isolering och minskade möjligheter i samhället. / Background: Depression is one of the most common mental illnesses today and it is equally stigmatized. Stigma can be linked to ignorance of mental illness. This makes it almost  impossible for individuals suffering from mental illness, such as depression, to be a part of society and express their feelings without receiving negativity related to their illness. In addition to this, the individuals in question are usually alone, i.e. they prefer isolation rather than the company of those who stigmatize them. This in turn gives rise to feelings of anxiety and hopelessness, inhibited recovery and even refusal to seek help and treatment. Purpose: The purpose of this study is to investigate how the experiences of stigmatization is expressed in blog posts among young adults with depression. Method: A qualitative study using text analysis was used. A total of eight blog posts were analysed to get the results. Blog posts were reviewed after the relevance for our purpose and study. Result: Three themes arose during the study. These are: "The fear of talking about their diagnosis", "Depression is a joke" and "Stigma from professionals". Conclusion: Individuals who experience stigmatization from society as a result of their mental illness experience reluctance to recovery, feelings of despair, worthlessness and malice that can lead to isolation and diminished opportunities in society.

The quality and the defectiveness of production are important factors in all sectors of engineering industry. On their improve there are a lot of effective tools, descriptive statistics is one of them. Descriptive statistic has many applicable tools but this work primarily focuses on desription of production using time series plot, testing of statistical hypothesis, testing of mutual dependencies of particular defects and control diagrams drawing. It is about a project that connects practice with theory.

Robotic exoskeleton technologies are one of the most active fields of robotics in recent years. Exoskeleton systems can give essential support for limb motions with enhanced strength and endurance, and they have a wide variety of therapeutic and supportive utility in life. These technologies have been extensively improved to be utilized for human power enhancement, worker injury prevention, human power assistance, and physical interface in augmented reality. Employees in the manufacturing and construction industries perform especially challenging duties, increasing their risk of health problems, disability, and medical leave, resulting in diminished job competitiveness and a shortage of qualified applicants. The usage of an exoskeleton might decrease muscular peak loads and lessen worker injury risks. This study includes a detailed analysis of employees wearing exoskeletons while doing various job-related duties. In this thesis, the tests assess the benefits of adopting exoskeletons in lowering human muscular activity and, as a result, weariness, and exhaustion. Unlike industrial robots, robotic exoskeleton technologies must be carefully built since they actually interact with actual users. The study used two widely available exoskeletons named Eksovest, an upper-body exoskeleton, and LegX, a lower-body exoskeleton. The study includes five applications: shoulder height weight-lifting, wall drilling, and roof drilling positions for the upper body Eksovest, and virtual chair and knee position for the lower body LegX. This application evaluated electromyography (EMG) signals which were collected using EMG sensors on the human body as supportive tools. Furthermore, the investigations compare the different volunteer’s body muscle data gathered by EMG sensors mounted on biceps, thigh, and calf muscles. The work also evaluates the accuracies of the data collecting procedures used in this study. Based on this study, it is discovered that by employing these exoskeletons may reduce muscular activity by up to 60%, hence enhancing the workforce's work life by reducing load and stresses on their body. This research will assist to raise the awareness by the outcomes of SMEs about the use of exoskeleton.