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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

[en] OPTIMIZATION OF TRANSFORMER AND MOBILE SUBSTATION STOCKS IN POWER SYSTEMS VIA MONTE CARLO SIMULATION AND GENETIC ALGORITHM / [pt] OTIMIZAÇÃO DE ESTOQUES DE TRANSFORMADORES E SUBESTAÇÕES MÓVEIS EM SISTEMAS DE POTÊNCIA VIA SIMULAÇÃO MONTE CARLO E ALGORITMO GENÉTICO

VENUS LIRIA SILVA MENDES 12 September 2024 (has links)
[pt] Em geral, as subestações são projetadas com transformadores em paralelo, operando a meia carga, para assegurar continuidade no fornecimento de energia mesmo que um transformador do grupo falhe. Contudo, essa prática implica em custos elevados, especialmente no que diz respeito ao arranjo de subestações. Uma solução alternativa é a utilização de estoques compartilhados de transformadores reservas e unidades de subestações móveis, que devem atender a um grupo de subestações com as mesmas características elétricas. Neste contexto, esta tese propõe a utilização temporária de unidades de subestações móveis, que devem atuar para atender à demanda de energia enquanto o transformador reserva é instalado. Essa estratégia aumenta a confiabilidade do sistema e reduz os custos operacionais e de investimento para as concessionárias de energia. No entanto, o sucesso dessa abordagem está intrinsecamente ligado ao dimensionamento e localização adequada dos estoques. Para que bons resultados sejam alcançados, é preciso dimensionar os estoques de forma que não haja investimento desnecessário ou um número insuficiente de equipamentos, e considerar pontos estratégicos de armazenamento, de forma que o tempo de deslocamento dos equipamentos sobressalentes até o ponto de falha garanta a minimização dos custos associados. Posto isso, esta tese apresenta duas metodologias de otimização baseadas em simulação Monte Carlo e Algoritmo Genético: uma para dimensionar o número de transformadores reservas e unidades de subestações móveis por ano; e outra para posicionar de forma adequada tais equipamentos em subestações com capacidade de armazenamento. Ambos os métodos foram aplicados a um grupo de transformadores de duas concessionárias reais, visando demonstrar a capacidade da metodologia de encontrar um conjunto de soluções factíveis do ponto de vista técnico e econômico. / [en] In general, substations are designed with transformers in parallel, operating at half load, to ensure continuity of power supply even if a transformer in the group fails. However, this practice involves high costs, especially with regard to the arrangement of substations. An alternative solution is the use of shared stocks of reserve transformers and mobile substation units, which must serve a group of substations with the same electrical characteristics. In this context, this thesis proposes the temporary use of mobile substation units, which must act to meet the energy demand while the reserve transformer is installed. This strategy increases system reliability and reduces operational and investment costs for electric utilities. However, the success of this approach is intrinsically linked to the proper sizing and location of stocks. For good results to be achieved, it is necessary to size stocks so that there is no unnecessary investment or an insufficient number of equipment, and consider strategic storage points, so that the time taken to move the spare equipment to the point of failure minimizes the associated costs. Thus, this thesis presents two optimization methodologies based on Monte Carlo simulation and Genetic Algorithm: one to size the number of spare transformers and mobile substation units per year; and another to properly locate such equipment in substations with storage capacity. Both methods were applied to a group of transformers from two real utilities, aiming at proving the method s ability to find a set of feasible solutions from a technical and economic point of view.
152

Vnímání výtvarného umění ve volném čase dětí a mládeže / Perception of Art and its Practise in the Free Time Activities with Children and Young People

MLS, Pavel January 2009 (has links)
The subject of diploma paper was anallysis of perception children and youth related to visual art. In the first chapter of theoretic part diploma paper I explain definitions related to the subject, i.e. that is fine art, aesthetics, culture, kitsch and relation of this species to the human being. In next chapters I acte problems, definition, delimitation of the odd time and I explain possibilities of transmission visual art to children and young people. The theoretic part of diploma paper is dedicated to possibilities of confrontation children and youth people with the visual art through various cultural institutions. This part of diploma paper is ended with basic dividing of spare-time activitity organizations. The practical part of diploma paper is dedicated to visual art project {\clq}qWho knows Piaristic square``, {\clq}qConversation`` and {\clq}qEntities in the nature``. Visual art expression of subjective experience evoked by visual perception of concrete image is the aim of this project. The project is intended for the children and youth in age between 8 and 24 years. I confront by means of projects both various components of visual art (painting, sculpture and architecture) and various movement epoch (gothic style, baroque and modern style). I wanted find the way how to transmit visual art to children and youth enjoyable, educational with aesthetic value. The end of the diploma paper summaries pieces of knowledge and perceptions from the visual art courses and projects.
153

L'art comme jeu : pratiques et utopies / Art as play : practices and utopias

Schmitt, Florent 26 September 2015 (has links)
L'art comme jeu n'est pas une simple métaphore. Il correspond à la forme que prennent de nombreuses œuvres d'art notamment les maquettes et miniatures contemporaines et aujourd'hui le jeu est représenté ou mis en scène dans de nombreuses expositions. Cependant l'artiste n'est pas un joueur comme les autres mais un joueur professionnel qui s'oppose à la figure du non-artiste ou de l'artiste amateur défendue par les artistes des avant-gardes qui avaient élevé le jeu au rang d'art. Alors que la consommation de l'art prend la forme d'un divertissement à grande échelle et que l'on assiste à une Disneylandisation des musées, l'art contemporain comme jeu ne semble plus aussi subversif que celui des années soixante. Pourtant l'art comme jeu en tant que modèle et outil de changement social perdure. C'est un art d'attitude, héritier des dernières avant-gardes, se tenant en dehors des frontières habituelles de l'art et réalisant le dépassement souhaité par les situationnistes ou Allan Kaprow. / Art as play is not only a metaphor. It is the particular form of many works of art, especially contemporary models and miniatures. Play itself is nowadays represented or staged in numerous exhibitions. However, the artist is not a player like any other but a professional player in contrast to the figure of the non-artist or amateur artist defended by avant-garde artists who had raised play to the level of art. While the consumption of art takes the form of large-scale entertainment and we witness a Disneylandisation of museums, contemporary art as play no longer seems as subversive as it did in the sixties. Yet art as play as model and tool for social change endures. It is an art of attitude, heir to the last avant-gardes, standing outside the usual boundaries of art and an art that achieves the desired by Allan Kaprow and the Situationists.
154

La plainte du chien battu, ou la poésie désenchanteresse (1991-2013) de Michel Houellebecq

Sultan, Martin 08 1900 (has links)
Ce mémoire propose une étude des poésies de Michel Houellebecq menée dans le respect des visées et du cadre théorique de la sociocritique (Duchet, Robin, Popovic). Chacun de ses trois chapitres explore un thème de recherche qui s’est imposé par sa prégnance dans l’œuvre étudiée : la vie urbaine, la vie sociale, les altérités de la ville. L’hypothèse principale est que l’écriture houellebecquienne capte des signes, des actes de langage, des représentations qui circulent dans la société française contemporaine, et qu’elle le fait de manière dynamique, c’est-à-dire en les soumettant à un travail scriptural qui critique leur usage et qui en modifie le sens. La « mise en texte » (Duchet) de la vie urbaine (premier chapitre) met à jour une domination de la ville et de ses habitants par les seules lois économiques. Elle décrit ainsi un monde qui n’est plus que marchand. Celle de la vie sociale et des liens interpersonnels (deuxième chapitre) démontre leur étonnante facticité et atteste que leur organisation restreint de plus en plus les libertés individuelles. Ce qui était un acquis de la modernité sociale : pouvoir bénéficier de « temps libre » pour prendre soin de soi et des proches, devient de plus en plus impossible. Enfin, celle des altérités de la ville (banlieue, province, nature – troisième chapitre), prouve que ces dernières n’offrent aucune alternative à l’hostilité du monde urbain et à la règle du chacun pour soi. Malgré ce diagnostic désolant, la poésie cherche à déceler ici ou là des traces d’espoir et de solidarité. / This master’s dissertation is a study of Michel Houellebecq’s poetry according to the theoretical framework of sociocritic (Duchet, Robin, Popovic). Urban life, social life and alterities of the city are the most present themes in the poetical work of the author. The main hypothesis is that the writing mobilizes and take over signs, linguistic acts and representations which float around in the French contemporary society, but in a dynamic way: the scriptural act of writing modifies their meaning and criticizes their common use. In the first chapter, we will discuss the “putting into text” (literal translation of the « mise en texte » concept by Duchet, which is the action of putting something into the form of a literary text) of urban life, which shines a light on how much the economic laws rule the city and its inhabitants. It describes a market world where money reigns. In the second chapter, the “putting into text” of social life and people-to-people ties shows how surprisingly artificial they are and certifies that their organization shrinks individual liberties more and more. Having free time to spend with your loved ones was once a given of social modernity but is now becoming difficult to manage. In the third and last chapter, the putting into text of the othernesses of the city (suburbs, province, nature) reveals that they offer no alternative to the hostility of the urban world and the fact that it is, and it will always be, every man for himself. Despite this distressing diagnosis, poetry tries to detect here and there hints of hope and solidarity.
155

Statické zajištění zámku / Static provision of castle

Kulla, Lukáš January 2016 (has links)
The aim of this final thesis was static protection for castle in Miroslavské Knínice. It was necessary to explore several respects and find signs of violation. Next analyze and propose suitable assurance of individual parts. Separe into the stages of construction and to consider the proposal in terms of ensuring the resistance of materials. Finally create a detailed documentation in the range suitable for performance. Based on engineering geology and visual survey was designed horizontal bracing prestressing cables at three levels. The first level "A" consists of a closed circuit of prestressed reinforced concrete passports, supplemented by the cross and construction of prestressed reinforced concrete passports. Next level "B,C" is used to secure the top of the building. Levels “B,C” are proposed using prestressed cable in spare cable channels.
156

Styrningens roll vid en strategiförändring : - från eftermarknad till att inkludera serieproduktion

Fristedt, Erika, Gustavsson, Malin January 2019 (has links)
Abstrakt Bakgrund: Bilindustrin står i dagsläget mitt i en omstrukturering av marknaden, där ansvar för produktion av detaljer förflyttas från biltillverkarna till underleverantörerna. Med denna omstrukturering följer högre krav på kvalitetsnivå och kostnadspress som underleverantörerna måste förhålla sig till. Fallföretaget (Företag X) gjorde cirka 2015 en strategiförändring från att enbart tillverka detaljer till reservdelsmarknaden (eftermarknad) till att även producera till nybilsmarknaden (serieproduktion) där målet var att skapa tillväxt och lönsamhet. Efter strategiförändringen har Företag X vuxit snabbt, men samtidigt har lönsamheten sjunkit till att 2018 vara obefintlig. Affärerna som upphandlas uppvisar positiva marginaler, vilket skapar förvirring i företaget om orsakerna bakom de finansiella prestationerna. Någonstans i deras processer sker något som styrningen inte fångar eller förvarnar om.   Syfte: Syftet med studien är att kartlägga strategiförändringen, implementeringen och Företag X:s styrning för att skapa en ökad förståelse för hur styrning kan stödja en strategiförändring från eftermarknad till att även inkludera serieproduktion. Vidare skall studien bidra med rekommendationer för kritiska egenskaper i styrningen som behöver fokuseras på i samband med en strategiförändring. Ett bidrag skapas även genom att avbilda den resa Företag X har genomgått och vilka utmaningar den har bidragit med.   Metod: Studien grundas i en fallstudie på Företag X, där en växling mellan referensramen och den empiriska insamlingen har nyttjats för att möjliggöra en justering av referensramen för att matcha studiens riktning. Genom att använda metoderna kunde vi uppfylla syftet med studien och därmed skapa ett relevant, teoretiskt bidrag till forskningen.   Resultat: Företag X:s styrning fångar inte beslutsrelevant information och därmed skapas en problematik i företaget. De måste förtydliga styrningen utefter de rekommendationer som delges. Vidare är de kritiska egenskaperna som behöver fokuseras på i styrningen: stödjande, signalerande, diagnostiserande, säkerställande, informationsspridande och motivationsskapare. / Abstract Background: The automobile industry is currently experiencing a reconstructuring of the market, where the responsibility of detail production is transferred between the car manufacturers to their subcontractors. The transference of responsibility also includes an increase in demand from the car manufacturers to the subcontractors to deliver higher quality products at a low cost. The case company (Company X) changed their strategy 2015 to include new car manufacturing in their already existing spare-part production with the intention to create growth and profitability. After the strategic change Company X has grown rapidly, but at the same time profitability has decreased and 2018 the profitability was non-existent. The business agreements show positive margins, which creates confusion in the company about is causing the decrease in financial performance. Somewhere in their processes something is happening that the management control systems aren’t capturing or warn about.        Purpose: The purpose of the study is to map the strategy change, implementation and Company X's management control to create an increased understanding of how management control can support a strategy change from only producing spare-parts to also include manufacturing of new cars. Furthermore, the study will contribute with recommendations for critical features of management control that needs to be focused upon during strategic change. A contribution is also created by depicting the journey that Company X has undergone and what challenges it has contributed with.   Method: The study is based on a case study of Company X, where an iteration between the reference frame and the empirical collection took place to enable an adjustment of the reference frame to match the direction of the study. By utilizing the methods, we were able to fulfill the purpose of the study and thereby create a relevant, theoretical contribution to the research.   Conclusion: Company X's management control does not capture decision-relevant information and thus problems are created within the organization. They ought to change their management control in accordance to the recommendations. Furthermore, the critical features that need to be focused on are: supportive, signaling, diagnosing, securing, information spreading and motivation creator.
157

[en] ANALYSIS OF THE CURRENT BRAZILIAN NAVY LOGISTIC STRUCTURE, RELATED THE SPARE PARTS, DUE THE CHALLENGES ARISING FROM THE INCORPORATION OF THE NEW SUBMARINES / [pt] ANÁLISE DA ATUAL ESTRUTURA LOGÍSTICA DA MARINHA DO BRASIL, RELACIONADA AOS SOBRESSALENTES, FRENTE AOS DESAFIOS DECORRENTES DA INCORPORAÇÃO DOS NOVOS SUBMARINOS

MARCELO REIS BEZERRA 11 February 2016 (has links)
[pt] A Marinha do Brasil presta o seu apoio logístico em cenários, por vezes, inóspitos, a partir de uma rede logística que, na sua origem, formou-se com base em conceitos e necessidades operativas, podendo também conviver com ineficiências e acomodações pela falta de concorrentes. Em 2008, fruto de uma decisão política e estratégica, dentro do contexto das relações internacionais no qual o Brasil está inserido, iniciou-se o processo de aquisição de novos submarinos convencionais (S-BR) e o apoio à elaboração do projeto e construção de um submarino nuclear (SN-BR), que se constitui no mais complexo e significativo projeto conduzido pela Marinha nos últimos tempos. Não obstante a importância desse projeto, estaria a cadeia de suprimento de sobressalentes (CSS) da Marinha pronta para prestar o devido apoio logístico ao novo meio operativo? O atual desenho de rede da Marinha atende as necessidades deste apoio? Qual o atual estágio de desenvolvimento da CSS e como promover uma maior integração dessa rede, com vistas a um melhor gerenciamento? Em meio a poucos estudos sobre o assunto e uma significativa carência de informações, o presente trabalho apresenta respostas a essas e outras questões correlatas, que se mostram cada vez mais prementes, diante da previsão de início dos testes de mar do primeiro submarino já 2017. Indubitavelmente, a Marinha é reconhecida pela sua grande capacidade de organização e pelo comprometimento de seus profissionais, mas serão necessárias algumas ações a mais para vencer este enorme desafio logístico. / [en] The Brazilian Navy provides logistics support in areas, sometimes inhospitable, using a logistics network that, in its origin, was formed on the basis of military concepts and needs, and, sometimes coexisting with inefficiencies and without competitors. In 2008, the result of a political and strategic decision, in a context of international relations in which Brazil is inserted, began the process of acquiring new Brazilian hunter-killer Submarine (SSK) and the support for design and construction of the Brazilian Nuclear-Powered Attack Submarine (SSN), which constitutes the most complex and significant Navy project in recent times. Despite the importance of this project, the Navy spare parts supply chain (SSC) would able to provide the appropriate logistics support for the new submarines? The current Navy network design meets the needs of this support? What is the current development stage of SSC and how to upgrade the integration of this network for improve the SCM? Few studies about this subject exist and a significant lack of information, therefore, this presents answers to these and other related issues that are becoming increasingly pressing, given the early prediction of sea tests of the first SSK submarine in 2017. Undoubtedly, the Navy is known to be a great organizational due to her organizational skills and the commitment of its seamen, but this project will require a little more to overcome this huge logistical challenge.
158

Causes of the bullwhip effect : A study of the bullwhip effect in the Volvo Group Service Market Logistics’ supply chain

Dahlin, Klara, Säfström, Oscar January 2021 (has links)
The bullwhip effect is defined as an upstream amplification of demand variability and has received interest within multinational companies for decades. As early as in the 1950’s, Forrester (1958) discussed what is today known as the bullwhip effect, which has a negative impact on the customer service, costs, and inventory investment in a supply chain (Lee et al., 1997). Even though the bullwhip effect has been noticed in various industries, the consequences, in form of decreased availability and increased costs the further up the supply chain the bullwhip goes, still remain. The employees at Volvo Group Service Market Logistics suspect that their supply chain has been affected by the bullwhip effect and want to know if it is correct and subsequently know why it has occurred. Therefore, this master’s thesis highlights the root causes of the bullwhip effect and presents strategies to mitigate it. To understand how the bullwhip effect affected the Volvo Group Service Market Logistics’ supply chain, the purpose was formulated as follow: The purpose of this study is to identify events in the Volvo Group Service Market Logistics’ supply chain where the bullwhip effect has occurred, its root causes, and how to reduce or eliminate the bullwhip effects.  The studied flow was from the Central Distribution Center (CDC) in Ghent, to the Regional Distribution Center (RDC) in Brazil, to the Dealers associated to the RDC in Brazil, and the customers. Data was collected from each node and events were studied to find bullwhip events. After sorting out the part numbers that passed the criteria for bullwhip events, the amount of data had to be reduced even more. A couple of different conditions were applied which resulted in four suitable bullwhip events. Thereafter, the authors conducted interviews with Logistics Managers at each node of the supply chain to find the root causes of the bullwhip effect in each studied event.  Among the several found root causes, lack of information transparency was the most frequent occurring root cause, found in three out of four studied bullwhip events. Insufficient communication and lack of information sharing cause bullwhip effects, and the authors found that improved communication both between and within the nodes will contribute to better planning, and consequently avoided bullwhip effects. Other root causes found were issues with the ordering system, lack of learning and experience, neglected lead times, fear of empty stock, price fluctuations, and phase-out of the spare part.  To reduce or eliminate the bullwhip effect, the focus was on mitigating the root causes since the root causes create opportunities for the bullwhip effect to occur. Four suggestions were given with suitable mitigation strategies found in the literature, where the four suggestions were sales campaigns, prepare for boosts, keep track of manually placed orders, and ordering system and Logistics Manager behavioural issues. The suggestions could then be connected to the different found root causes. The stated suggestions and mitigation strategies focused on mitigating the root causes in a long-term perspective and consequently the bullwhip effect itself.

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