Thesis (M.S.)--Massachusetts Institute of Technology, Alfred P. Sloan School of Management, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY. / Bibliography: leaves 128-129. / by Bruce William Lamar. / M.S.

Este trabalho aborda o problema de programação da produção em um flexible flow line com tempos de setup. De acordo com a literatura, este ambiente pode ser considerado como um caso especial do Flow Shop com múltiplas máquinas, onde as tarefas podem saltar estágios. Neste estudo, foram analisados dois problemas: o primeiro, com tempos de setup independentes da sequência, e o segundo, com setup dependente da sequência de tarefas. Além disso, o setup das máquinas para as tarefas pode ser antecipado ou não. No primeiro caso, as máquinas de um estágio podem ser preparadas para o processamento de uma tarefa antes do seu término no estágio anterior. Se o setup não pode ser antecipado, a tarefa deve esperar o seu término no estágio de produção anterior. Este ambiente produtivo pode ser encontrado em um vasto número de indústrias tais como química, eletrônica, automotiva e têxtil. A medida de desempenho dos problemas é a duração total da programação (makespan). Este é um critério apropriado para sistemas de produção com grandes cargas de trabalho e em que a utilização dos recursos produtivos em longo prazo deve ser otimizada. O exame da literatura mostrou que há poucos estudos abordando a programação em flexible flow line. Considerando este aspecto, este trabalho apresenta heurísticas construtivas originais para a obtenção de programações apropriadas ao problema mencionado. Uma extensiva experimentação computacional foi executada para avaliar o desempenho relativo das heurísticas. Os resultados experimentais foram analisados e discutidos. / This work addresses the job scheduling on a flexible flow line with separate setup times. According to the literature, this scheduling problem can be considered as a special case of the Flow Shop with multiple machines, where the jobs may skip stages. Two modeled problems have been studied. In the first scheduling problem the setup times are sequence independent, and in the second one these times are sequence dependent. Moreover, the machine setup task can be either anticipatory or non-anticipatory. In the first case, a k-stage machine may be prepared for a job processing before its completion on the k-1 production stage. Otherwise, the setup task must wait for the job completion on the former production stage. This production environment can be found in a number of industries such as chemicals, electronics, automotive, and textiles. The performance measure of the production schedules is the makespan, that is, the total time to complete the schedule. This is an appropriate performance criterion for production systems with large workloads, and where the utilization of productive resources in the long term should be optimized. The literature examination has shown that there is a small number of studies dealing with flexible flow line scheduling. Having this in mind, this work introduces original constructive heuristics in order to obtain suitable schedules for the aforementioned scheduling problem. An extensive computational experience has been carried out in order to evaluate the relative performance of the heuristics. Experimental results are discussed.

A disciplina de bioquímica é parte integrante do currículo de todos os cursos de graduação da Área Biológica, sendo pré-requisito para outras disciplinas. São de conhecimento geral as dificuldades que os estudantes enfrentam no aproveitamento desta disciplina. Para investigar estas dificuldades foi criado um Plantão de Dúvidas on line, disponível para estudantes graduandos, com três finalidades: (i) oferecer um suporte aos estudantes para facilitar o prosseguimento dos seus estudos, (ii) analisar as dúvidas apresentadas como uma estratégia para diagnóstico das dificuldades mais freqüentes e (iii) realizar uma classificação do nível cognitivo das dúvidas recebidas. Ao final do período de atendimento, foram recebidas e respondidas 416 questões. Houve várias questões conceituais, a enorme maioria tendo sido problemas ou exercícios a serem resolvidos. Os assuntos mais freqüentemente questionados foram: (i) metabolismo celular (42,5%), principalmente metabolismo de lipídios e a respiração celular; (ii) conceitos básicos (14,2%) sobre aminoácidos, tampão entre outros; (iii) estrutura de proteínas (8,7%) e (iv) enzimas (7,0%). Estes percentuais correlacionam-se com a carga horária dedicada a cada um dos tópicos na maioria das disciplinas. Uma importante dificuldade encontrada foi a integração dos processos metabólicos. Em relação ao nível cognitivo, 61% das dúvidas foram de nível baixo, 28% foram de nível médio e 11% foram de nível alto. Uma análise mais aprofundada é necessária para investigar as causas das dificuldades apontadas. / The biochemistry discipline integrates the curriculum of all graduation courses on the Biological Area and is a basis for other disciplines. The students difficulties in this discipline are already widely recognized. To investigate these difficulties, we created a drop-in on line service that had three purposes: (i) to give support to students learning by answering their questions and solving their problems whenever they appear, (ii) to analyze the questions presented, as a strategy to diagnose the most prevalent difficulties and (3) to carry through a classification of the cognitive level of the received doubts. After the period of attendance of this service on line, 416 questions were received and answered. There were many conceptual questions being the majority related to problems and exercises. The most frequent questions dealt with cell metabolism (42.5%), mainly lipid metabolism and aerobic metabolism; basic concepts (14.2%) such as about amino acids and buffer, protein structure (8.7%) and enzymes (7.0%). These percentages are correlated to the number of hours dedicated to each subjects in the disciplines. The main difficulty founded was the integration of metabolic processes. Related to the cognitive level, 61% of the doubts had been of low level, 28% had been of average level and 11% had been of high level. A more in-deep analysis will be necessary to investigate the causes of the pointed difficulties.

Vários compostos utilizados ou produzidos pelo homem quando lançados no meio ambiente, ou mesmo em estações de tratamento de esgoto, não são facilmente degradados ou removidos. Desse modo, acabam voltando às estações de tratamento de água, que em sua maioria utilizam métodos que não são capazes de remover tais compostos, podendo até aumentar o efeito biológico destes. A detecção destes compostos é um desafio para a Química Analítica, já que ocorrem em baixas concentrações. Degradou-se uma mistura de quatro hormônios ¾ três naturais, 17 β-estradiol (E2), estrona (E1) e estriol (E3), e um sintético, 17 α-etinilestradiol (EE2) ¾ em água de abastecimento público pela fotocatálise heterogênea solar, utilizando-se o fotocatalisador dióxido de titânio suportado em um reator de placa plana operado com reciclo. Foi também desenvolvido e validado um método analítico totalmente automatizado que possibilitou detectar e quantificar baixas concentrações dos quatro hormônios. Foram obtidos limites de quantificação de 10 μg L-1, com a extração de 125 μL de amostra, com coeficiente de variação (< 20%) e exatidão (todos entre 80 a 120%) dentro dos limites aceitáveis para este tipo de análise. Foi possível verificar que a eficiência de degradação atingiu mais de 90% em menos de 4 horas para todos os hormônios. Mesmo com esse nível de degradação não foi possível a remoção da atividade estrogênica. Só houve uma redução significativa após 9 h de degradação. Possivelmente, a atividade estrogênica foi mantida pela concentração restante dos hormônios e/ou pela formação de produtos de degradação que também apresentavam atividade biológica. Alguns desses compostos foram propostos, sendo alguns conhecidos na literatura. No entanto, com as análises realizadas, não foi possível se ter certeza de que os compostos gerados no tratamento são realmente os sugeridos. / Several compounds used or produced by man, when released into the environment, or even in sewage treatment plants, are not easily degraded or removed. Thus, these compounds eventually return to water treatment plants, which mostly use methods incapable of removing them, and may even enhance their biological effect. The detection of these compounds is a challenge to Analytical Chemistry, as they occur at low concentrations. A mixture of four hormones were degraded ¾ three of them of natural origin, 17β-estradiol (E2), estrone (E1), and estriol (E3) and a synthetic one, 17α-ethinyl estradiol (EE2) ¾ in public water supply by solar heterogeneous photocatalysis, using supported titanium dioxide as the photocatalyst in a flat-plate reactor in recycling mode. A fully automated analytical method was developed and validated making it possible to detect and quantify low concentrations of the four hormones. Quantification limits of 10 μg L-1 were achieved with the extraction of a 125 μL-sample, with coefficients of variation (< 20%) and accuracy (all between 80 and 120%) were acceptable limits for this type of analysis. It was possible to observe that the degradation performance reached more than 90% in less than 4 hours for all hormones. Even with this level of degradation it was not possible to remove the estrogenic activity. There was only a significant reduction after 9 h of degradation. Possibly, the estrogenic activity was maintained by the remaining concentration of the hormones and/or by degradation by-products which still present biological activity. Some of these compounds were proposed, some of which have been already published in the literature. However, with the performed analyses, it was not possible to ascertain that the generated compounds during treatment are actually the ones here suggested.

Made available in DSpace on 2016-03-15T19:43:10Z (GMT). No. of bitstreams: 1 Joana Alves Brito de Azambuja.pdf: 516549 bytes, checksum: a1144455353bb1d3c7d96237b03e63ad (MD5) Previous issue date: 2007-12-04 / Fundo Mackenzie de Pesquisa / The new Information and Communication Technologies establish a new socialcultural paradigm, through its radical influence on the society. This fact has modified significantly the educational environment, mainly, for keeping in xeque the learning conceptions and the new paper of its actors. In this direction, the virtual learning environments start to be an interaction and collaborative place, where the knowledge construction is possible. The emergent On-line Education demands a new pedagogical concept that attends to the necessities of students and professors who act in this educational modality. It s necessary to point out the pedagogical function of the communication interactive tools ( diário de bordo , fórum of discussion, chat, portfólio e e-mail) and describe how it can propitiate the learning process, just measure the new meanings social construction by student s orientation, in a formative evaluation proposal. It s essential, therefore, to reflect on the quality and the effectiveness of learning, through put in doubt this new activity field, and think about On-line Education as an educational modality really worried about to the pedagogical of the virtual world . / As novas tecnologias da informação e comunicação, por sua influência radical em diferentes dimensões da sociedade, estabelecem um novo paradigma sociocultural . Esse fato tem alterado significativamente as práticas educativas, principalmente por colocar em xeque as concepções de aprendizagem e o novo papel dos sujeitos envolvidos nesse processo. Os ambientes virtuais de aprendizagem (AVA) surgem, então, como realidade emergente no novo contexto da Educação On-Line, enquanto espaço de interação e de construção coletiva do conhecimento. Entende-se também que esse novo cenário educacional passa a demandar uma discussão crítica sobre conceitos e práticas pedagógicas que possam responder às necessidades de alunos e professores que atuam nessa modalidade de ensino. Nesse sentido, o objetivo aqui é situar a função pedagógica das ferramentas interativas de comunicação presentes nos AVA (diário de bordo, Chat, fórum de discussão, portfólio e correio eletrônico) e descrever de que forma elas podem favorecer o acompanhamento e a orientação dos alunos na construção social de novos significados a partir de uma proposta de avaliação formativa. Trata-se, portanto, de refletir sobre a qualidade e a eficácia da aprendizagem através da problematização desse novo campo de ação, para que se possa pensar na Educação On-Line como uma modalidade educativa realmente preocupada com o pedagógico do mundo virtual . Esse fato tem alterado significativamente as práticas educativas, principalmente por colocar em xeque as concepções de aprendizagem e o novo papel dos sujeitos envolvidos nesse processo. Os ambientes virtuais de aprendizagem (AVA) surgem, então, como realidade emergente no novo contexto da Educação On-Line, enquanto espaço de interação e de construção coletiva do conhecimento. Entende-se também que esse novo cenário educacional passa a demandar uma discussão crítica sobre conceitos e práticas pedagógicas que possam responder às necessidades de alunos e professores que atuam nessa modalidade de ensino. Nesse sentido, o objetivo aqui é situar a função pedagógica das ferramentas interativas de comunicação presentes nos AVA (diário de bordo, Chat, fórum de discussão, portfólio e correio eletrônico) e descrever de que forma elas podem favorecer o acompanhamento e a orientação dos alunos na construção social de novos significados a partir de uma proposta de avaliação formativa. Trata-se, portanto, de refletir sobre a qualidade e a eficácia da aprendizagem através da problematização desse novo campo de ação, para que se possa pensar na Educação On-Line como uma modalidade educativa realmente preocupada com o pedagógico do mundo virtual .

abstract: Switching surges are a common type of phenomenon that occur on any sort of power system network. These are more pronounced on long transmission lines and in high voltage substations. The problem with switching surges is encountered when a lot of power is transmitted across a transmission line/network, typically from a concentrated generation node to a concentrated load. The problem becomes significantly worse when the transmission line is long and when the voltage levels are high, typically above 400 kV. These overvoltage transients occur following any type of switching action such as breaker operation, fault occurrence/clearance and energization, and they pose a very real danger to weakly interconnected systems. At EHV levels, the insulation coordination of such lines is mainly dictated by the peak level of switching surges, the most dangerous of which include three phase line energization and single-phase reclosing. Switching surges can depend on a number of independent and inter-dependent factors like voltage level, line length, tower construction, location along the line, and presence of other equipment like shunt/series reactors and capacitors. This project discusses the approaches taken and methods applied to observe and tackle the problems associated with switching surges on a long transmission line. A detailed discussion pertaining to different aspects of switching surges and their effects is presented with results from various studies published in IEEE journals and conference papers. Then a series of simulations are presented to determine an arrangement of substation equipment with respect to incoming transmission lines; that correspond to the lowest surge levels at that substation. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018

The threshold characteristics of multimode laser oscillators are considered in detail, and a new model is given for semiconductor diode lasers. Analytical expressions and numerical solutions are obtained for mode amplitudes, and over-all spectral characteristics of lasers operating above and below threshold. The theoretical results are i n agreement with experimental data. The band-ta-band absorption is included in the model and i t ' s effect is studied on the mixed broadening.

Central line-associated bloodstream infection (CLABSI) at the local healthcare setting exceeded the benchmark of 0 CLABSI. The Infection Prevention and Control (IPC) department determined that a role as CLABSI nurse champion would address the problem; however, no comprehensive education on CLABSI prevention and maintenance was available at the site. The purpose of this project was to develop a CLABSI prevention and maintenance education module using Knowles's adult learning theory and the chain of infection model. The practice-focused question asked whether a CLABSI educational module would provide the necessary information to educate nurse champions on CLABSI prevention and maintenance. The education module was presented to 9 local experts, composed of the Infection Prevention and Control (IPC) director, doctor of medicine, microbiologist, biomedical technologists, IPC nurses, and 2 staff nurses, who evaluated the CLABSI education module. An 11-question Likert-scale questionnaire that included an option for recommendations for improvement was used by the expert panel to evaluate the module. Of the 11 questions, only 3 were scored as strongly agree or agree, indicating a need to modify the module to raise the education level of the content and to include the clinical standards, objectives, and dressing-change procedures. After modifications, the education module was scored again, and 100% met the criteria and the recommendations of the expert panel. The project has the potential to promote positive social change by increasing the knowledge of the CLABSI nurse champions and by reducing the risk of CLABSI at the site.

<p>A common assumption in marketing is the wider variety of product a corporation has, the better for the consumer: more product - more choices. Companies often develop a line extension to broaden consumer range through product attributes including quality, function and design. These developed attributes within the product are not always optimal for the consumer. As a result, companies often become entangled in having a price higher than the cost and benefit of the products. This essay aims to analyze the consumer value of line extension products and how these evaluations relate to extended line product pricing. A quantitative approach has been used, while data has been collected through structured questions with multiple-choice answers. Various theories concerning the products of different levels, consumer attitudes and pricing of line extension products have been assessed for this essay. The data used for survey purposes is from three different surveys in three different grocery stores. The results reveal a connection between the customer evaluation and pricing, although not as strong as initially thought. The price of organic coffee and whole meal pasta, in relation to its respective core, was relatively the same. Also, the customer evaluation of these products was equally related (See Figure 21). Generally a corporation prices products according to specific attributes. Lactose-free milk was an exception by being priced 157% higher than the other line extension products. This variation in price happens without correlation to consumers’ evaluation.</p>

<p>In this bachelor thesis, cable fault locators are studied for use on the overhead electrode lines in the HVDC (High Voltage Direct Current) Light project Caprivi Link. The cable fault locators studied operates with the principle of travelling waves, where a pulse is sent in the tested conductor. The time difference is measured from the injection moment to the reflection is received. If the propagation speed of the pulse is known the distance to the fault can be calculated. This type of unit is typically referred to as a TDR (Time Domain Reflectometer). The study is performed as a computer simulation where a simplified model of a TDR unit is created and applied to an electrode line model by using PSCAD/EMTDC. Staged faults of open circuit and ground fault types are placed at three distances on the electrode line model, different parameters of the TDR units such as pulse width and pulse amplitude along with its connection to the electrode line are then studied and evaluated. The results of the simulations show that it is possible to detect faults of both open circuit and ground fault types with a suitable TDR unit. Ground faults with high resistance occurring at long distances can be hard to detect due to low reflection amplitudes from the injections. This problem can somewhat be resolved with a function that lets the user compare an old trace of a “healthy” line with the new trace. The study shows that most of the faults can be detected and a distance to the fault can be calculated within an accuracy of ± 250 m. The pulse width of the TDR needs to be at least 10 μs, preferable 20 μs to deliver high enough energy to the fault to create a detectable reflection. The pulse amplitude seams to be of less significance in this simulation, although higher pulse amplitude is likely to be more suitable in a real measurement due to the higher energy delivered to the fault. The Hipotronics TDR 1150 is a unit that fulfil these requirements and should therefore be able to work as a line fault locator on the electrode line.</p>