Re-entrant lines are widely used in many manufacturing systems, such as semiconductor, electronics, etc. However, the performance analysis of re-entrant lines is largely unexplored due to its complexity. In this thesis, we present iterative procedures to approximate the production rate of re-entrant lines with Bernoulli reliability of machines. The convergence of the algorithms, uniqueness of the solution, and structural properties, have been proved analytically. The accuracy of the procedures is investigated numerically. It is shown that the approaches developed can either provide a lower bound or a closed estimate of the system production rate. Finally, a case study of automotive ignition component line with re-entrant washing operations is introduced to illustrate the applicability of the method. The results of this study suggest a possible route for modeling and analysis of re-entrant systems.

Re-entrant permutation flow shop problems occur in practical applications such as wafer manufacturing, paint shops, mold and die processes and textile industry. A re-entrant material flow means that the production jobs need to visit at least one working station multiple times. A comprehensive review gives an overview of the literature on re-entrant scheduling. The influence of missing operations received just little attention so far and splitting the jobs into sublots was not examined in re-entrant permutation flow shops before. The computational complexity of makespan minimization in re-entrant permutation flow shop problems requires heuristic solution approaches for large problem sizes. The problem provides promising structural properties for the application of a variable neighborhood search because of the repeated processing of jobs on several machines. Furthermore the different characteristics of lot streaming and their impact on the makespan of a schedule are examined in this thesis and the heuristic solution methods are adjusted to manage the problem’s extension.

Made available in DSpace on 2016-01-26T18:49:49Z (GMT). No. of bitstreams: 1 NAIME_DISSERTACAO_11_10_2012.pdf: 824433 bytes, checksum: 4eb20bd7cb15d69a602cb0acbbdfa2a1 (MD5) Previous issue date: 2012-08-15 / The interest in the topic covered in this research is due to the fact that students who begin the Pedagogy Course in a private College in Minas Gerais State, have a variety of profiles, thus, some are high school graduated, others majored in teaching courses (Professional Technical) and some work as teachers in kindergarten schools yet, and teach for the first grades of elementary school. Professors of the Education Course often bring to the course coordination difficulties they face in teaching to a group that has such diversity and heterogeneity. Thus, this study aimed to analyze the social representations and expectations of academic entrants of Pedagogy about the course, featuring a variety of profiles, trying to analyze the reasons for the choice of a course in teacher training in higher education. The research was configured in a qualitative approach, involving study of case. The research tools that facilitated achieving the intended goals were: semi-structured interviews, documented analysis procedures and testimonials. Students who participated in the research were selected by their profiles, thus, high school graduated academics, graduated for teaching (Professional Technical) and those who already work as teachers in kindergarten schools and first grades of elementary school. 30 entrants were chosen, four of each academic profile who agreed to participate anonymously. Understanding the diversity of perceptions and expectations of customers should help subsidize and rethink the pedagogical project of the Pedagogy Course focused in the research. / O interesse pelo tema abordado nesta pesquisa se deve ao fato de que os alunos ingressantes do curso de Pedagogia de uma instituição privada de Ensino Superior no interior de Minas Gerais apresentam uma diversidade de perfis, ou seja, alguns são egressos do Ensino Médio, outros, egressos do Magistério (técnico-profissional) e alguns já atuam como docentes em escolas de Educação Infantil e séries iniciais do Ensino Fundamental. Muitas vezes, os docentes do curso trazem à coordenação as dificuldades que enfrentam ao lecionar para um grupo que apresenta essa diversidade e heterogeneidade. Assim, a presente pesquisa tem por objetivo analisar as representações sociais dos acadêmicos ingressantes de Pedagogia e verificar suas expectativas em relação ao curso. É preciso lembrar que tais alunos apresentam diversidade de procedência, dessa forma, tentar-se-á identificar as razões da escolha de um curso na área de formação de educadores em nível superior. A pesquisa se configurou em uma abordagem qualitativa, envolvendo um estudo de caso e os procedimentos metodológicos que viabilizaram a consecução do objetivo pretendido foram: entrevistas semiestruturadas, análise documental e bibliográfica. Participaram da pesquisa os acadêmicos ingressantes que foram selecionados por procedência. O universo da pesquisa constituiu-se de 12 ingressantes (de um total de 30), destes, quatro acadêmicos de cada procedência concordaram em participar de forma anônima. A compreensão da diversidade de representação da clientela deverá contribuir para repensar o projeto pedagógico do curso e subsidiar as ações dos professores envolvidos na formação de futuros profissionais docentes.

Made available in DSpace on 2016-07-18T17:54:19Z (GMT). No. of bitstreams: 1 NAIME_DISSERTACAO_11_10_2012.pdf: 824433 bytes, checksum: 4eb20bd7cb15d69a602cb0acbbdfa2a1 (MD5) Previous issue date: 2012-08-15 / The interest in the topic covered in this research is due to the fact that students who begin the Pedagogy Course in a private College in Minas Gerais State, have a variety of profiles, thus, some are high school graduated, others majored in teaching courses (Professional Technical) and some work as teachers in kindergarten schools yet, and teach for the first grades of elementary school. Professors of the Education Course often bring to the course coordination difficulties they face in teaching to a group that has such diversity and heterogeneity. Thus, this study aimed to analyze the social representations and expectations of academic entrants of Pedagogy about the course, featuring a variety of profiles, trying to analyze the reasons for the choice of a course in teacher training in higher education. The research was configured in a qualitative approach, involving study of case. The research tools that facilitated achieving the intended goals were: semi-structured interviews, documented analysis procedures and testimonials. Students who participated in the research were selected by their profiles, thus, high school graduated academics, graduated for teaching (Professional Technical) and those who already work as teachers in kindergarten schools and first grades of elementary school. 30 entrants were chosen, four of each academic profile who agreed to participate anonymously. Understanding the diversity of perceptions and expectations of customers should help subsidize and rethink the pedagogical project of the Pedagogy Course focused in the research. / O interesse pelo tema abordado nesta pesquisa se deve ao fato de que os alunos ingressantes do curso de Pedagogia de uma instituição privada de Ensino Superior no interior de Minas Gerais apresentam uma diversidade de perfis, ou seja, alguns são egressos do Ensino Médio, outros, egressos do Magistério (técnico-profissional) e alguns já atuam como docentes em escolas de Educação Infantil e séries iniciais do Ensino Fundamental. Muitas vezes, os docentes do curso trazem à coordenação as dificuldades que enfrentam ao lecionar para um grupo que apresenta essa diversidade e heterogeneidade. Assim, a presente pesquisa tem por objetivo analisar as representações sociais dos acadêmicos ingressantes de Pedagogia e verificar suas expectativas em relação ao curso. É preciso lembrar que tais alunos apresentam diversidade de procedência, dessa forma, tentar-se-á identificar as razões da escolha de um curso na área de formação de educadores em nível superior. A pesquisa se configurou em uma abordagem qualitativa, envolvendo um estudo de caso e os procedimentos metodológicos que viabilizaram a consecução do objetivo pretendido foram: entrevistas semiestruturadas, análise documental e bibliográfica. Participaram da pesquisa os acadêmicos ingressantes que foram selecionados por procedência. O universo da pesquisa constituiu-se de 12 ingressantes (de um total de 30), destes, quatro acadêmicos de cada procedência concordaram em participar de forma anônima. A compreensão da diversidade de representação da clientela deverá contribuir para repensar o projeto pedagógico do curso e subsidiar as ações dos professores envolvidos na formação de futuros profissionais docentes.

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No / Using SANS to map the deformation of individual polymer chains in the vicinity of re-entrant corners in a contraction−expansion flow, we show that stress singularities at such corners, predicted by formulations of fluid dynamics that lack a molecular basis, do not cause extreme deformation of the chains. Multiscale modeling based on a nonlinear tube theory incorporating appropriate relaxation processes quantitatively reproduces the observed scattering, thus providing further evidence for the universality of the tube model for polymer flow.

Le résonateur matriochka est conçu à partir de résonateurs coaxiaux ré-entrants créant ainsi des sauts d’impédances (SIR). La thèse développe alors des innovations théoriques sur la technologie matriochka en proposant des modèles analytiques précis sur le comportement fréquentiel et du facteur de qualité du résonateur. Les modélisations mettent en relief l’existence de degrés de liberté au sein du résonateur matriochka induisant une flexibilité du rapport de forme du résonateur. Les degrés de liberté créent ainsi une multitude de configurations du résonateur matriochka pour une fréquence fondamentale et un facteur de qualité donnés. Par conséquent, une optimisation en volume est réalisée pour concevoir deux filtres en bande L et C afin de minimiser leur encombrement. Une étude de la tenue en puissance dans le vide est également effectuée pour le filtre en bande L. Une méthode conjointe d’optimisation de la tenue en puissance et de minimisation en volume est alors proposée pour ce filtre. Ainsi, les modélisations et les optimisations sont employées afin de concevoir et de fabriquer deux filtres hyperfréquences. Le premier est un filtre de transmission en bande L conçu pour l’application de navigation Galileo qui propose une alternative d’encombrement et une tenue en puissance dans le vide élevée. Enfin, le second est un filtre de réception en bande C conçu, fabriqué et mesuré pour l’application de télémesure qui propose de meilleures performances en réjection et un volume réduit par rapport à l’existant. Finalement, la technologie matriochka est une alternative de résonateur par rapport à l’état de l’art en proposant, selon les configurations, un rejet élevé des harmoniques et un volume réduit pour une fréquence fondamentale et un facteur de qualité donnés. / The matriochka resonator is based on reentrant coaxial Stepped Impedance Resonator (SIR). So, the thesis develops theoretical innovations on the matriochka technology offering accurate analytical models on the frequency and the quality factor behaviors of the resonator. The models prove the existence of degrees of freedom within the matriochka resonator which allows to get different form factors of the resonator. The degrees of freedom create many configurations of the matriochka resonator for a fundamental frequency and a quality factor. Consequently, a volume optimization is realized to design a L-band filter and a C-band filter. A multipactor study is also carried out for the L-band filter. So, a joint optimization method of the multipactor and the volume minimization is proposed for this filter. Thus, the models and optimisations are used in the order to to design and fabricate the microwave filters. The first one is a transmission L-band filter for the navigation application Galileo which offers a volume alternative and a high power in the vaccum. Then, the second one is a reception C-band filter for the telemetry application which offers wide spurious free-performance and a low volume compared to the state of the art. Finally, for a frequency and a quality factor and depending on the configurations, the matriochka technology offers an alternative of the resonator volume, and it offers a wide spurious free- performance and a low volume compared to the state of the art.

Background: A common assumption in business research is that first-movers in new markets often tends to have competitive advantages that sequent companies find difficult to compete with. Recently the formal research usability has begun to be questioned. The empirical basis there search of this area rests on, is criticized of being too homogenous. The research that’s been done have often focused on specific industries with certain types of entry barriers. Purpose: The purpose of this paper is to study if there are benefits to being a first-mover in the industry for grocery bags online. The study will use a methodological triangulation in an effort to make a methodological contribution in this research field. Theory: The theoretical framework used in the study is First-mover advantage and Later-entrant advantage. Delimitations: The quantitative part of the study will analyze 15 companies dealing with grocery bags online in Sweden. In the qualitative part of the study a delineation of the population will be made. Five companies were chosen for this part of the study. Methodology: A methodological triangulation was used to increase coherence in the study. Information about the 15 companies consisted of different types of documents such as annual reports and press releases. In the qualitative part of the study semi-structured interviews with different respondents at the different companies was done. / Bakgrund: Ett vanligt förekommande antagande inom företagsekonomin är att företag som är först in på en marknad ofta har långtgående konkurrensfördelar som efterföljande företag har svårt att konkurrera med. På senare tid har forskningens användbarhet börjat bli ifrågasatt. Det empiriska underlaget som forskningsfältet vilar på kritiseras för att vara för homogent. Forskningen är ofta gjord på industriella företag med specifika inträdesbarriärer. Syfte: Syftet med studien är att undersöka faktorerna som avgör en first-movers fördelar samt resultatet av fördelarna. Studien undersöker företag som levererar färdiga matkassar på internet i Sverige. Med hjälp av en metodologisk triangulering kommer ett bidrag att göras till forskningsfältet. Teoretiskt perspektiv: Det teoretiska ramverk som använts i undersökningen är first-mover advantage och Later-entrant advantage. Avgränsning: Undersökningen är avgränsad till att undersöka registrerade bolag i Sverige som levererar färdigplanerade matkassar på internet. Urvalet för den kvantitativa undersökningen består av 15 företag. I den kvalitativa undersökningen, består urvalet av 5 företag. Metod: Undersökningen är uppdelad i två delar där två olika metoder användes. Dels en kvantitativ undersökning och en kvalitativ undersökning. En metodtriangulering genomfördes för att öka samstämmigheten i undersökningen. Information om de 15 företagen hämtades från olika typer av dokument, som årsredovisningar och pressmeddelanden. I den kvalitativa undersökningen genomfördes semistrukturerade intervjuer med olika nyckelpersoner på företagen.

This thesis considers the problem of performance modeling, analysis and control of capacitated re-entrant lines. Specifically, the first part of the thesis develops an analytical framework for the modeling, analysis and control of capacitated re-entrant lines, which is based on Generalized Stochastic Petri nets (GSPN) framework. The corresponding scheduling problem is systematically formulated, and the structure of the optimal policy is characterized and compared to that identified for "traditional" re-entrant lines. The second part of thesis addresses the problem of developing a systematic and computationally effective method for computing the optimal scheduling policy for any given configuration of capacitated re-entrant line. Specifically, the underlying scheduling problem is transformed to a Markov Decision Process (MDP) problem and an algorithm that systematically generates the MDP formulation for any given fab configuration is developed. The third part of thesis develops an effective approximating scheme based on the Neuro-Dynamic Programming (NDP) theory. In its general definition, the NDP method seeks the approximation of the optimal relative value function of the underlying MDP formulation by a parameterized function. Hence, an approximating structure for the considered problem is proposed and the quality of the generated approximations is systematically assessed. More specifically, this part of the thesis develops a set of "feature" functions and the mathematical apparatus necessary to evaluate the considered approximating scheme through a numerical experiment. The obtained results indicate that good quality approximations can be achieved by considering a set of features that characterize the distribution of the running process instances to the various processing stages and their lower order interactions. The last part of the thesis exploits the performance models developed in its earlier parts in order to provide an analytical characterization of the optimality of various deadlock resolution strategies for Markovian resource allocation systems under the objective of maximizing throughput.

The aim of this research project was to determine and describe the challenges and advantages presented to artists taking part in student theatre festivals as well as the challenges and advantages presented to the organisers of such festivals. A further aim of the study was to determine, address and describe the functions of a student theatre festival within the community in which it takes place and then to describe how such a festival could be most effectively organised and planned. The study is original, since very little research has been done on this topic in the past. When collecting data for the project, no documents were found describing such study projects. The findings of this study are also important, since guidelines are given aiding festival organisers and future festival organisers in the effective planning and organising of such an event. The research was conducted using three research methodologies. These were a survey of scholarship, structured and semi-structured interviews and action research. The information gathered by the first two methodologies is described in chapter 2. Information gathered by the action research methodology is described in chapter 3, which is a case study of the 2001 and 2002 Krêkvars arts festivals. After the first festival had ended, it was evaluated in terms of which methods of planning were successful and which were not. The second festival was then planned, adapting the unsuccessful methods and emphasising the successful ones. Thereafter the festival was evaluated again, formulating suggestions for the effective planning and organisation of a student theatre festival. From this research project, it can be concluded that student theatre festivals present many advantages and challenges for those involved. It is therefore necessary for the organisers to be well prepared for the task at hand and to do sufficient planning in order to most effectively organise such an event. / Dissertation (MA (Drama))--University of Pretoria, 2005. / Drama / unrestricted