Thesis (M.S.)--University of Michigan, 1993.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the increase of the customer's demand degree, the search for the quality improvement is consolidated as one of the strategies more proceeded in the different market segments. The Six Sigma initiative is a system of quality management that has been showing efficient and effective in guide organizations in the way of improvement, taking the quality as fundamental reference. Related to the Six Sigma initiative, the problem of ascending research of this dissertation it was summed up: how to control in an objective way the performance Six Sigma in processes of continuous production? In a way, the objective of this dissertation is to develop, in the Six Sigma context, an objective model of performance control in processes of continuous production. The used research procedures were, with base in the objectives, the exploratory research and, with base in the technical procedures, the bibliographical research, the research of case study type and the experimental research. For fund the dissertation, was proceeded with the materialization of a theoretical reference on models of performance control and on the Six Sigma initiative, being identified in the sequence, in three organizations, two peculiarities of the processes of continuous production: the importance of the performance control in processes of continuous production, and the care exercised with the expedition of products doesn't conform. A model of Six Sigma performance control in processes of continuous production was proposed, model that contemplated the use of two performance indicators that were denominated sigma level and loss level. The model was positively evaluated, because the results demonstrated that the model of performance control presents characteristics capable to bring more objectivity in the performance control in processes of continuous production, because when different weights are attributed at the indicators of acting sigma level and loss level, different objective orientations of the model are had. In this way, the proposition and the evaluation of the model of Six Sigma performance control in processes of continuous production offered a larger understanding concerning the thematic proposal; besides showing the importance of models that they allow the control of capable managerial actions they increase the customers' satisfaction: fact that interferes in the profit and survival of the organizations. / Com o aumento do grau de exigência do cliente, a busca pela melhoria da qualidade está se consolidado como uma das estratégias mais seguidas nos diferentes segmentos de mercado. A iniciativa Seis Sigma é um sistema de gestão da qualidade que tem se mostrado eficiente e eficaz em nortear organizações no caminho da melhoria, tomando a qualidade como referência fundamental. Relacionada à iniciativa Seis Sigma concretizou-se o problema de pesquisa ascendente desta dissertação: como controlar de maneira objetiva o desempenho Seis Sigma em processos de produção contínua? De tal modo, o objetivo desta dissertação é desenvolver, no contexto do Seis Sigma, um modelo objetivo de controle do desempenho em processos de produção contínua. Os procedimentos de pesquisa utilizados foram, com base nos objetivos, a pesquisa exploratória e, com base nos procedimentos técnicos, a pesquisa bibliográfica, a pesquisa do tipo estudo de caso e a pesquisa experimental. Para alicerçar a dissertação, procedeu-se com a concretização de um referencial teórico sobre modelos de controle de desempenho e sobre a iniciativa Seis Sigma, sendo identificadas na seqüência, em três organizações, duas peculiaridades dos processos de produção contínua: a importância do controle do desempenho em processos de produção contínua, e o cuidado exercido com a expedição de produtos não conformes. Propôs-se então um modelo de controle do desempenho Seis Sigma em processos de produção contínua, modelo que contemplou a utilização de dois indicadores de desempenho que foram denominados nível sigma e nível de perda. Avaliou-se positivamente o modelo, pois os resultados demonstraram que o modelo de controle do desempenho apresenta características capazes de trazer mais objetividade no controle do desempenho em processos de produção contínua, pois quando diferentes pesos são atribuídos aos indicadores de desempenho nível sigma e nível de perda, têm-se diferentes orientações objetivas do modelo. Deste modo, a proposição e a avaliação do modelo de controle do desempenho Seis Sigma em processos de produção contínua ofereceram um maior entendimento acerca da temática proposta, além de mostrar a importância de modelos que permitam o controle de ações gerenciais capazes de aumentar a satisfação dos clientes: fato que interfere na lucratividade e sobrevivência das organizações.

O objetivo geral desta pesquisa foi avaliar a existência de uma orientação do controle do desempenho utilizados nas pequenas e médias empresas hoteleiras e sua adequação aos fatores-chave de competitividade do setor. Essa pesquisa foi realizada na região central do Estado de São Paulo contemplando os circuitos Paulista da Chapada Guarani e Ecocaipira. A pesquisa fundamenta-se no vácuo existente entre a visão estratégica e visão operacional na gestão empresarial, ou seja, a falta de integração entre as diretrizes estratégicas e a operação das empresas. A medição de desempenho é uma atividade que visa melhorar gradativamente a atuação das empresas, fazendo com que elas se mantenham competitivas. O trabalho de campo foi dividido em três fases: a primeira e segunda fase concentrou-se na abordagem quantitativa. A primeira fase teve o propósito de identificar a quantidade de empresas hoteleiras na região central do Estado de São Paulo, considerando o mapeamento da equipe de pesquisadores do GEOPE da EESC - USP. A segunda fase teve o propósito de caracterizar a preocupação com o controle do desempenho e com as medidas de desempenho da organização. A terceira fase concentrou-se na abordagem qualitativa, na qual foi feito um estudo de caso com o propósito de verificar os indicadores utilizados pelas empresas e verificar se estão orientados para a competitividade. Como principal resultado, observou-se que os mecanismos de controle do desempenho são adequados as características do contexto social de cada organização e, como conseqüência, está relacionado à estratégia da empresa. Ainda, concluiu-se que os indicadores de desempenho das grandes e das pequenas empresas hoteleiras são semelhantes, a diferença está na formalização desses indicadores. / The general aim of this research is to evaluate the existence of an orientation of the organizational control utilized in small and medium sized hotels and its adequacy for the key competitivity factors of the sector. The research was conducted in the central region of São Paulo State comprising the Paulista Circuits of Chapada Guarani and Ecocaipira, based on the vacuum that exists between the strategic and operational visions in the entrepreneural management, i. e., the lack of integration between the strategic guidelines and the operation of the enterprises. The performance measurement is an activity that aims to gradually improve the action of enterprises, so that they keep themselves competitive, which is the basis in the strategic process. The field work was divided into three stages, of which the first and the second focused on the quantitative approach. In the first phase the aim was the identification and quantification of hotels in the central region of São Paulo state, considering the mapping of the research group of GEOPE at São Carlos Engineering School - USP. In the second phase, the concern about the performance control and measurement of the organization was characterized. Finally, the third phase focused on the qualitative approach, in which a case study was conducted in order to verify the indicators utilized by the enterprises and check that they are oriented towards competitiveness. As a main result, it was possible to observe that the performance control mechanisms are adequate for the characteristics of the social context of each organization and, therefore, related to the enterprise strategy. The performance indicators of large and small hotels are similar, differing only in their formalization.

No description available.

The development of high power density three-phase ac converter has been a hot topic in power electronics area due to the increasing needs in applications like electric vehicle, aircraft and aerospace, where light weight and/or low volume is usually a must. Many challenges exist due to the complicated correlations in a three-phase power converter system. In addition, with the emerging SiC device technology the operating frequency of the converter can be potentially pushed to the range from tens of kHz to hundreds of kHz at higher voltage and higher power conditions. The extended frequency range brings opportunities to further improve the power density of the converter. Technologies based on existing devices need to be revisited. In this dissertation, a systematic methodology to analyze and design the high power density three-phase ac converter is developed. All the key factors of the converter design are explored from the high density standpoint. Firstly, the criteria for the passive filter selection are derived and the relationship between the switching frequency and the size of the EMI filter is investigated. A function integration concept as well as the physical design approach is proposed. Secondly, a topology evaluation method is presented, which provides the insight into the relationships between the system constraints, operating conditions and design variables. Four topologies are then compared with the proposed approach culminating with a favored topology under the given conditions. Thirdly, a novel average model is developed for the selected topology, and used for devising a carrier-based control approach with simple calculation and good regulation performance. Fourthly, the converter failure mode operation and corresponding protection approaches are discussed and developed. Finally, a 10 kW three-phase ac/ac converter is built with the SiC devices. All the key concepts and ideas developed in this work are implemented in this hardware system and then verified by the experimental results. / Ph. D.

Wireless personal area networks have emerged as an important communication infrastructure in areas such as at-home healthcare and home automation, independent living and assistive technology, as well as sports and wellness. Wireless personal area networks, including body sensor networks, are becoming more mature and are considered to be a realistic alternative as communication infrastructure for demanding services. However, to transmit data from e.g., an ECG in wireless networks is also a challenge, especially if multiple sensors compete for access. Contention-based networks offer simplicity and utilization advantages, but the drawback is lack of predictable performance. Recipients of data sent in wireless sensor networks need to know whether they can trust the information or not. Performance measurements, monitoring and control is of crucial importance for medical and healthcare applications in wireless sensor networks. This thesis focuses on development, prototype implementation and evaluation of a performance management system with performance and admission control for wireless sensor networks. Furthermore, an implementation of a new method to compensate for clock drift between multiple wireless sensor nodes is also shown. Errors in time synchronization between nodes in Bluetooth networks, resulting in inadequate data fusion, are also analysed. / <p>QC 20120529</p>

These days, a wide range of autonomous systems, such as automobiles, delivery drones, and embedded household systems, are becoming more and more common in our society. This trend is projected to continue in the future. To effectively manage these dynamic systems, ensuring their safe operation is crucial for the well-being of our lives. Control of safety-critical systems has gained significant attention in recent years, particularly in the field of nonlinear control. While the mathematical tools for characterizing safety are well-established, there are still numerous challenges to be addressed when it comes to developing methodologies for synthesizing nonlinear control systems. This report investigates the similarity between the two control schemes, the prescribed performance control and control barrier function. Its purpose is to shed light on the development of control methodology in safetycritical systems. While both methods have been successfully constructed and developed recently, there is no existing report that clarifies their similarities. To gain a deeper understanding of the latest safety-critical control and investigate these similarities, this report aims to provide interesting insights and contribute to the further development of methodology. The key insight arises from the fact that the prescribed performance control can be considered a method based on barrier functions. Consequently, it can be regarded as a control barrier-based controller. In order to demonstrate the similarities and make a comparison between the two, a unified problem setting is presented. Once we have properly converted the problem, we can proceed with a comparison using numerical simulations. The results presented in this report demonstrate that the prescribed performance controller can be implemented using separate reciprocal CBF methods. Furthermore, it shows that the performance achieved is comparable to that of the CLF-CBF QP, which utilizes optimization techniques to ensure stability and safety requirements. These findings raise new questions regarding the relationship between these two approaches. Ultimately, the report delves into a deeper understanding of how model-free methods achieve superior performance compared to model-based methods that heavily rely on optimization. / Idag blir ett brett spektrum av autonoma system, som bilar, leveransdrönare och inbyggda hushållssystem, allt vanligare i vårt samhälle. Denna trend förväntas fortsätta i framtiden. För att effektivt hantera dessa dynamiska system är det avgörande att säkerställa att de fungerar på ett säkert sätt. Styrning av säkerhetskritiska system har fått stor uppmärksamhet under de senaste åren, särskilt inom området icke-linjär styrning. Även om de matematiska verktygen för att karakterisera säkerhet är väletablerade, finns det fortfarande många utmaningar att ta itu med när det gäller att utveckla metoder för att syntetisera olinjära styrsystem. Denna rapport undersöker likheten mellan de två kontrollsystemen, den föreskrivna prestandakontrollen och kontrollbarriärfunktionen. Syftet är att belysa utvecklingen av styrmetodik i säkerhetskritiska system. Även om båda metoderna har konstruerats och utvecklats framgångsrikt på senare tid, finns det ingen befintlig rapport som klargör deras likheter. För att få en djupare förståelse för den senaste säkerhetskritiska kontrollen och undersöka dessa likheter, syftar denna rapport till att ge intressanta insikter och bidra till den fortsatta utvecklingen av metodiken. Den viktigaste insikten härrör från det faktum att den föreskrivna prestandakontrollen kan betraktas som en metod baserad på barriärfunktioner. Följaktligen kan den betraktas som en styrbarriärbaserad styrenhet. För att visa på likheterna och göra en jämförelse mellan de två presenteras en enhetlig problemställning. När vi har omvandlat problemet på rätt sätt kan vi gå vidare med en jämförelse med hjälp av numeriska simuleringar. De resultat som presenteras i denna rapport visar att den föreskrivna prestandaregulatorn kan implementeras med separata reciproka CBF-metoder. Dessutom visar de att den uppnådda prestandan är jämförbar med den för CLFCBF QP, som använder optimeringstekniker för att säkerställa stabilitets- och säkerhetskrav. Dessa resultat väcker nya frågor om förhållandet mellan dessa två metoder. I slutändan ger rapporten en djupare förståelse för hur modellfria metoder uppnår överlägsen prestanda jämfört med modellbaserade metoder som i hög grad förlitar sig på optimering.

This thesis treats the control of sound synthesis of bowed string instruments based on physical modelling. The work followed two approaches: (a) a systematic exploration of the influence of control parameters (bow force, bow velocity, and bow-bridge distance) on the output of a physical model of the violin, and (b) measurements and analyses of the bowing parameters in real violin playing in order to model and parameterize basic classes of bowing patterns for synthesis control.First a bowed-string model based on modal solutions of the string equation is described and implemented for synthesis of violin sounds. The behaviour of the model is examined through simulations focusing on playability, i.e. the control parameter space in which a periodic Helmholtz motion is obtained, and the variations of the properties of the simulated sound (sound level and spectral centroid) within this parameter space. The response of the model corresponded well with theoretical predictions and empirical expectations based on observations of real performances. The exploration of the model allowed to define optimal parameter regions for the synthesis, and to map sound properties on the control parameters.A second part covers the development of a sensor for measuring the bow force in real violin performance. The force sensor was later combined with an optical motion capture system for measurement of complete sets of bowing parameters in violin performance.In a last part, measurements of the control parameters for basic classes of bowing patterns (sautillé, spiccato, martelé, tremolo) are analyzed in order to propose a realistic control of the sound synthesis. The time evolution of the bowing parameters were modelled by analytical functions, which allowed to describe and control simulated bowing patterns by a limited set of control parameters. For sustained bowing patterns such as détaché, control strategies for basic elements in playing (variations in dynamic level, bow changes) were extracted from exemplary measurements, and simple rules deduced, which allowed extrapolation of parameters to modified bow strokes with other durations and at different dynamic levels. / Denna avhandling behandlar styrning av syntes av stråkinstrument med tillämpningar inom fysikalisk modellering av musikinstrument. Problemet har angripits i två steg, först genom en systematisk undersökning av inflytandet av styrparametrarna i violinspel (stråkkraft, stråkhastighet, och avstånd stråke-stall) på utsignalen från en fysikalisk modell, följt av mätningar och analyser av stråkningsparametrarna i normalt violinspel med syfte att modellera och parameterisera grundläggande klasser av stråkarter för styrning av syntesen. En modell av interaktionen mellan stråke-sträng har utvecklats baserad på modal syntes och modellen har implementerats för syntes av violintoner. Modellen har utforskats genom simuleringar inriktade dels på spelbarheten, dvs. gränserna för den parameterrymd inom vilken en periodisk Helmholtz-rörelse erhålls, och dels på variationerna hos det syntetiserade ljudets egenskaper (ljudnivå och spektral centroid) inom detta parameterområde. Modellens egenskaper motsvarade väl de teoretiska prediktionerna och förväntade resultat från observationer av violinster. Utforskningen av modellen gjorde det möjligt att definiera optimala parameterområden för styrning av syntesen, och även avbilda ljudens egenskaper på styrparametrarna. En sensor för mätning av stråkkraften utvecklades för att kunna genomföra mätningar under normalt spel. Sensorn kombinerades senare med ett optiskt system för rörelseanalys vilket gjorde det möjligt att mäta kompletta uppsättningar av stråkparametrar under spel. Uppmätta styrparametrar för grundläggande klasser av stråkarter (sautillé, spiccato, martelé, tremolo) analyserades för att ge tillgång till realistiska styrförlopp av syntesen. Stråkningsparametrarna modellerades med analytiska funktioner, för att kunna beskriva och styra simulerade stråkningsförlopp med ett begränsat antal modellparametrar. För stråkarter med uthållna toner som détaché utvecklades styrstrategier för grundläggande element i spelet, som ändringar i styrkegrad och stråkväxlingar, utifrån mätningar på typfall. Enkla regler formulerades för att kunna extrapolera parametrarna till modifierade stråk med andra durationer och styrkegrader. / Cette thèse porte sur le contrôle de la synthèse sonore par modélisation physique des instruments à corde frottée. Il se base, d’une part, sur l’exploration systématique de l’influence des paramètres de contrôle (pression d’archet, vitesse de l’archet et distance au chevalet) sur le comportement du modèle, et d’autre part, sur la mesure et l’analyse du contrôle effectif qu’exerce l’instrumentiste afin de modéliser et paramétriser des modes de jeu typiques pour le contrôle de la synthèse. Un modèle de corde frottée basé sur la résolution modale de l’équation de la corde est d’abord présenté et implémenté pour la synthèse sonore du violon. Le comportement du modèle physique est ensuite examiné en effectuant un grand nombre de simulations et se concentre sur deux aspects : la “jouabilité", c’est-à-dire l’espace des paramètres de contrôle dans lequel un mouvement de Helmholtz périodique est obtenu, et les variations des propriétés du son synthétisé (niveau sonore et centroïde spectral) à l’intérieur de cet espace de paramètres. Un très bon accord a été trouvé entre, d’une part, le résultat des simulations et, d’autre part, les prédictions théoriques ou empiriques basées sur l’expérience des instrumentistes. Cette exploration systématique a permis de définir des régions optimales pour le jeu dans l’espace des paramètres de contrôle et de décrire quantitativement la correspondance entre les propriétés sonores pertinentes et les paramètres de contrôle. La deuxième partie de ce travail concerne la mise au point d’un capteur pour mesurer la force d’appui de l’archet sur la corde dans un contexte de jeu réel. Le capteur est ensuite combiné avec un système optique de capture du mouvement afin de mesurer les paramètres de jeu du violoniste. La dernière partie présente l’analyse des mesures de ces paramètres de contrôle pour des modes de jeu typiques (sautillé, spiccato, martelé, tremolo), afin de proposer un contrôle réaliste de la synthèse sonore. L’évolution temporelle des paramètres de jeu est modélisée par des fonctions analytiques, ce qui permet de décrire et de simuler différents modes de jeu par un nombre limité de paramètres. Pour les modes de jeu soutenus tels que le détaché, les mesures permettent de décrire des stratégies de contrôle pour des tâches typiques (variation de niveau sonore, changement de direction d’archet), et des procédures simples ont été déduites, permettant d’extrapoler les paramètres de contrôle afin de changer le niveau sonore ou la durée des coups d’archet. / QC 20100714. Gemensam forskarutbildning KTH och Universite Pierre et Marie Curie (Paris VI).

There is no full-length investigation of postcoloniality in Bangladeshi Bengali literature. This is partly because Bangladesh had no separate identity under colonial rule, being just another part of greater India. Then, at partition, it became one section of the unnatural union that was Pakistan. These two identities have kept Bangladesh as a relatively unknown domain, at least to the Western academy. The other reason in the context of literary postcolonial studies is that these have concentrated on writing in English, whereas Bangladeshi literature is almost completely in the national language. This study offers a discussion of the postcoloniality of contemporary Bangladeshi theatre via analysis of selected playtexts.

There is no full-length investigation of postcoloniality in Bangladeshi Bengali literature. This is partly because Bangladesh had no separate identity under colonial rule, being just another part of greater India. Then, at partition, it became one section of the unnatural union that was Pakistan. These two identities have kept Bangladesh as a relatively unknown domain, at least to the Western academy. The other reason in the context of literary postcolonial studies is that these have concentrated on writing in English, whereas Bangladeshi literature is almost completely in the national language. This study offers a discussion of the postcoloniality of contemporary Bangladeshi theatre via analysis of selected playtexts.