919 resultados para Many-to-many-assignment problem


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Pós-graduação em Ciências Sociais - FFC

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Pós-graduação em Medicina Veterinária - FMVZ

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In this paper a novel Branch and Bound (B&B) algorithm to solve the transmission expansion planning which is a non-convex mixed integer nonlinear programming problem (MINLP) is presented. Based on defining the options of the separating variables and makes a search in breadth, we call this algorithm a B&BML algorithm. The proposed algorithm is implemented in AMPL and an open source Ipopt solver is used to solve the nonlinear programming (NLP) problems of all candidates in the B&B tree. Strategies have been developed to address the problem of non-linearity and non-convexity of the search region. The proposed algorithm is applied to the problem of long-term transmission expansion planning modeled as an MINLP problem. The proposed algorithm has carried out on five commonly used test systems such as Garver 6-Bus, IEEE 24-Bus, 46-Bus South Brazilian test systems, Bolivian 57-Bus, and Colombian 93-Bus. Results show that the proposed methodology not only can find the best known solution but it also yields a large reduction between 24% to 77.6% in the number of NLP problems regarding to the size of the systems.

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Atmospheric Discharges are responsible for several lost in the electrical system therefore it´s done studies to find ways to reduce the problem caused by discharges. This branch of engineering is necessary the gathering, stock and analysis of large quantity of data to validate or refuse the many studies produced about it The CENDAT proposed a project to collect data on induced voltages in distribution lines and current waveform of the lightning, but a difficulty that arose was the accumulation of data due to lack of manpower available to catalog all the data collected. Thinking in this difficulty, the engineer Acacio Silva Neto CENDAT´s researcher with trainees began to develop a program to solve this problem. This work keeps the development of this program in order to solve the problem of accumulation of data

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The use of polymeric materials has grown in recent years due to its high durability features, atoxicity, shaping versatility and environment resistance. However, while these features represent good advantages to several industry sectors, it results in one of the most serious environmental problems of contemporary society: the rising accumulation of these material, mainly due to the inadequate disposal of waste. Meanwhile, in order to minimize this problem, some mitigation techniques comes up (arises), among which the use of biodegradable polymers has been gaining attention. Because of their easily action of microorganisms, such material degrade more rapidly, becoming integrated to nature. Furthermore, due to the fact of biodegradation is a natural process, occurring through the action if micro-organisms in the environment itself, it is considered the “cleaner” alternative found so far to plastic components reincorporation in the nature. Among the micro-organisms capable of biodegradation process are the filamentous fungi. These micro-organisms have many advantages over the others, the major one being the capacity to produce a range of enzymes capable of degrading different materials. In this context, the present review made it possible to see the importance of this process as an agent of environmental preservation, suggest the use of blends to minimize the problems of cost and flexibility of biodegradable polymeric materials, as well as noting the lack of studies related to this subject nowadays

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There are considerations of that the education of Physics of the way as comes being driven us textbooks and consequently in classroom, is distant and distorted of their real purpose. We notice that the education of this science through the Physical school discipline, has I assume a character of preparation for university entrance exams exercises resolution, exceling for the memorization of formulae and by the mathematical solutions, fact that looks to cause to it is lacking of motivation and to the disinterest of the students regarding his contents. Since we are surrounded by phenomena, events, elements of the nature, new technologies, objects and so many others that can be explained and many times until applied and/or reproduced by means of physical concepts, there is no reason for treat to Physical as somewhat academic and remote of the reality. The little interest of high school students by the discipline of Physics and their poor performance in the learning of his contents has led to the search of new paths, resources and strategies that promote a more meaningful learning. Taking into account these facts, we seek in this course conclusion work, observe, analyze and apply concepts of the Physical one in multiple elements of ours routine, doing use of the interdisciplinary nature as a possible mechanism. The animals exert a fascination on most people. Much of what we see in their way of being and behaving can be explained by the laws of Physics and its models. Their physique, behavior and activities involve diverse movements, communication and sensing as physical limitations varied. Zoologists and physicists build models in an attempt to explain or understand animal behavior using well-established physical principles. The creation of physical models is going to approach a problem, identifies the fundamental information and removing all of the irrelevant details. An example... (Complete abstract click electrnic access below)

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Due to the large economic development associated with the growing consumerist lifestyle of our capitalist society, the problem of uncontrolled solid waste generation worsens, which one is considered to be one of the main responsible factors for environmental degradation. As a case study and in order to solve the problem of large generation of municipal solid waste, this work aims to study the “plano diretor” of Rio Claro city, São Paulo. The “plano diretor” is a municipal law that provides guidelines for the administration of the city, which include guidelines for the management of solid waste generated in the city. The guidelines required in order to write the “plano diretor” are provided by the national law “estatuto da cidade”, providing information for the planning and development of the cities, as well as the management of the urban environment. However, only the “estatuto da cidade” does not provide enough instructions for creating management plans in order to solve the many problems from the urban environment. Thus, studies have been done about urban and environmental management, to understand how municipal management plans should be structured. As a form of seeking information that can complement the “plano diretor” to the creation of policies for managing solid waste of the city, the “Política Nacional de Resíduos Sólidos”(PNRS) emerges in 2010 as a document which provides principles, objectives and guidelines to create plans for Solid Waste Management at the national, state, regional and municipal levels. Therefore, it was possible to make a joint analysis of the “plano diretor” of Rio Claro with the PNRS to identify what is already done within the municipality about the solid waste management, and identify which aspects are most significant in the municipal solid waste management that the national policy provides. Yet studies have been done on the current municipal solid waste management...

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Engenharia Mecânica - FEIS

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Urban space occupation occurs in an extremely disordered way. Political, economical and social aspects converge to create a problem that affects mostly poor people who are impelled to occupy areas where social and environmental problems are likely to emerge. Floods, landslides and different forms of pollution have more effects on the most vulnerable groups. In many cases, actions taken by the government legitimate this structure and reinforce its reproduction. This work seeks to confirm both that poor people are vulnerable to social and environmental problems resulting from inappropriate urban solid waste disposal and that the local government contributes to this situation. It is assumed that the issue is related first to the government’s disregard for poor people who live in unhealthy places and, second, to the inability of such people to demand for better living conditions. In this study, a waste disposal area within Jardim Graminha neighborhood in Leme (São Paulo) was selected to be analyzed by means of systematic observation. The study clearly shows that poor people living near that area where different types of garbage are disposed are vulnerable and the government does not control the situation. It is also pointed out that governmental intervention and the use of political and technical tools are necessary for planning and managing the area to mitigate these problems and to decrease poor people’s social and environmental vulnerability.

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Pós-graduação em História - FCHS

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The recent likely extinction of the baiji (Chinese river dolphin [Lipotes vexillifer]) (Turvey et al. 2007) makes the vaquita (Gulf of California porpoise [Phocoena sinus]) the most endangered cetacean. The vaquita has the smallest range of any porpoise, dolphin, or whale and, like the baiji, has long been threatened primarily by accidental deaths in fishing gear (bycatch) (Rojas-Bracho et al. 2006). Despite repeated recommendations from scientific bodies and conservation organizations, no effective actions have been taken to remove nets from the vaquita’s environment. Here, we address three questions that are important to vaquita conservation: (1) How many vaquitas remain? (2) How much time is left to find a solution to the bycatch problem? and (3) Are further abundance surveys or bycatch estimates needed to justify the immediate removal of all entangling nets from the range of the vaquita? Our answers are, in short: (1) there are about 150 vaquitas left, (2) there are at most 2 years within which to find a solution, and (3) further abundance surveys or bycatch estimates are not needed. The answers to the first two questions make clear that action is needed now, whereas the answer to the last question removes the excuse of uncertainty as a delay tactic. Herein we explain our reasoning.