976 resultados para location-allocation problem
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The central goal of this paper is thinking about the Brazilian military power and its linking to the international ambitions of the country in the 21st century. After a comparative analysis to other BRICs and with a historical one about Brazil's strategic irrelevance, we aim to establish what the minimum military capacity Brazil would need in order to meet the country's latest international interests. Similarly, it will be discussed if the National Strategy of Defense, approved in 2008, and the recent strategic agreements signed with France represent one more step toward this minimum military capacity.
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The calls for colleges and universities to improve their productivity are coming thick and fast in Brazil. Many studies are suggesting evaluation systems and external criteria to control the quality of teaching and research in universities. Since universities and colleges are not profit-oriented organizations (considering only the legitimate and serious research and teaching organizations, of course), the traditional microeconomics and administrative variables used to measure efficiency do not have any direct function. An alternative would be to create an "as if" market control system to evaluate performance in universities and colleges. Internal budget and resources allocation mechanism can be used as incentive instruments to improve quality and productivity. It will be the main issue of this article.
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In the past thirty years, a series of plans have been developed by successive Brazilian governments in a continuing effort to maximize the nation's resources for economic and social growth. This planning history has been quantitatively rich but qualitatively poor. The disjunction has stimulated Professor Mello e Souza to address himself to the problem of national planning and to offer some criticisms of Brazilian planning experience. Though political instability has obviously been a factor promoting discontinuity, his criticisms are aimed at the attitudes and strategic concepts which have sought to link planning to national goals and administration. He criticizes the fascination with techniques and plans to the exclusion of proper diagnosis of the socio-political reality, developing instruments to coordinate and carry out objectives, and creating an administrative structure centralized enough to make national decisions and decentralized enough to perform on the basis of those decisions. Thus, fixed, quantified objectives abound while the problem of functioning mechanisms for the coordinated, rational use of resources has been left unattended. Although his interest and criticism are focused on the process and experience of national planning, he recognized variation in the level and results of Brazilian planning. National plans have failed due to faulty conception of the function of planning. Sectorial plans, save in the sector of the petroleum industry under government responsibility, ha e not succeeded in overcoming the problems of formulation and execution thereby repeating old technical errors. Planning for the private sector has a somewhat brighter history due to the use of Grupos Executivos which has enabled the planning process to transcend the formalism and tradition-bound attitudes of the regular bureaucracy. Regional planning offers two relatively successful experiences, Sudene and the strategy of the regionally oriented autarchy. Thus, planning history in Brazil is not entirely black but a certain shade of grey. The major part of the article, however, is devoted to a descriptive analysis of the national planning experience. The plans included in this analysis are: The Works and Equipment Plan (POE); The Health, Food, Transportation and Energy Plan (Salte); The Program of Goals; The Trienal Plan of Economic and Social Development; and the Plan of Governmental Economic Action (Paeg). Using these five plans for his historical experience the author sets out a series of errors of formulation and execution by which he analyzes that experience. With respect to formulation, he speaks of a lack of elaboration of programs and projects, of coordination among diverse goals, and of provision of qualified staff and techniques. He mentions the absence of the definition of resources necessary to the financing of the plan and the inadequate quantification of sectorial and national goals due to the lack of reliable statistical information. Finally, he notes the failure to coordinate the annual budget with the multi-year plans. He sees the problems of execution as beginning in the absence of coordination between the various sectors of the public administration, the failure to develop an operative system of decentralization, the absence of any system of financial and fiscal control over execution, the difficulties imposed by the system of public accounting, and the absence of an adequate program of allocation for the liberation of resources. He ends by pointing to the failure to develop and use an integrated system of political economic tools in a mode compatible with the objective of the plans. The body of the article analyzes national planning experience in Brazil using these lists of errors as rough model of criticism. Several conclusions emerge from this analysis with regard to planning in Brazil and in developing countries, in general. Plans have generally been of little avail in Brazil because of the lack of a continuous, bureaucratized (in the Weberian sense) planning organization set in an instrumentally suitable administrative structure and based on thorough diagnoses of socio-economic conditions and problems. Plans have become the justification for planning. Planning has come to be conceived as a rational method of orienting the process of decisions through the establishment of a precise and quantified relation between means and ends. But this conception has led to a planning history rimmed with frustration, and failure, because of its rigidity in the face of flexible and changing reality. Rather, he suggests a conception of planning which understands it "as a rational process of formulating decisions about the policy, economy, and society whose only demand is that of managing the instrumentarium in a harmonious and integrated form in order to reach explicit, but not quantified ends". He calls this "planning without plans": the establishment of broad-scale tendencies through diagnosis whose implementation is carried out through an adjustable, coherent instrumentarium of political-economic tools. Administration according to a plan of multiple, integrated goals is a sound procedure if the nation's administrative machinery contains the technical development needed to control the multiple variables linked to any situation of socio-economic change. Brazil does not possess this level of refinement and any strategy of planning relevant to its problems must recognize this. The reforms which have been attempted fail to make this recognition as is true of the conception of planning informing the Brazilian experience. Therefore, unworkable plans, ill-diagnosed with little or no supportive instrumentarium or flexibility have been Brazil's legacy. This legacy seems likely to continue until the conception of planning comes to live in the reality of Brazil.
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As wind power generation undergoes rapid growth, lightning and overvoltage incidents involving wind power plants have come to be regarded as a serious problem. Firstly, lightning location systems are discussed, as well as important parameters regarding lightning protection. Also, this paper presents a case study, based on a wind turbine with an interconnecting transformer, for the study of adequate lightning and overvoltage protection measures. The electromagnetic transients circuit under study is described, and computational results are presented.
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This paper presents a new generalized solution for DC bus capacitors voltage balancing in back-to-back m level diode-clamped multilevel converters connecting AC networks. The solution is based on the DC bus average power flow and exploits the switching configuration redundancies. The proposed balancing solution is particularized for the back-to-back multilevel structure with m=5 levels. This back-to-back converter is studied working with bidirectional power flow, connecting an induction machine to the power grid.
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A relation between a rice irrigation system and mosquito breeding was established in a study undertaken at the Ribeira Valley Experimental Station, from January through December 1992. Flooding favoured Anopheles (Nyssorhynchus) and Culex (Melanoconion) species, while empty paddies condition were propitious to Aedes scapularis and Culex (Culex) species. Compared with a more primitive area of the same region, several species showed high a degree of adaptation to the anthropic environment. Among them, Anopheles albitarsis, a potential malaria vector that breeds in the irrigation system, has shown immature stage production thirteen times higher than at the natural breeding sites. In addition, Ae. scapularis, An. oswaldoi, Cx. bastagarius, and Cx. chidesteri presented high levels of synanthropy.
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Formaldehyde was the first air pollutant, which already in the 1970s emerged as a specifically non-industrial indoor air quality problem. Yet formaldehyde remained an indoor air quality issue and the formaldehyde level in residential indoor air is among the highest of any indoor air contaminant. Formaldehyde concentrations in 4 different indoor settings (schools, office buildings, new dwellings and occupied dwellings) in Portugal were measured using Photo Ionization Detection (PID) equipment (11,7 eV lamps). All the settings presented results higher than the reference value proposed by Portuguese legislation. Furthermore, occupied dwellings showed 3 units with results above the reference. We could conclude that formaldehyde presence is a reality in monitored indoor settings. Concentration levels are higher than the Portuguese reference value for indoor settings and these can indicate health problems for occupants.
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This paper presents an investigation into cloud-to-ground lightning activity over the continental territory of Portugal with data collected by the national Lightning Location System. The Lightning Location System in Portugal is first presented. Analyses about geographical, seasonal, and polarity distribution of cloud-to-ground lightning activity and cumulative probability of peak current are carried out. An overall ground flash density map is constructed from the database, which contains the information of more than five years and almost four million records. This map is compared with the thunderstorm days map, produced by the Portuguese Institute of Meteorology, and with the orographic map of Portugal. Finally, conclusions are duly drawn.
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Financial literature and financial industry use often zero coupon yield curves as input for testing hypotheses, pricing assets or managing risk. They assume this provided data as accurate. We analyse implications of the methodology and of the sample selection criteria used to estimate the zero coupon bond yield term structure on the resulting volatility of spot rates with different maturities. We obtain the volatility term structure using historical volatilities and Egarch volatilities. As input for these volatilities we consider our own spot rates estimation from GovPX bond data and three popular interest rates data sets: from the Federal Reserve Board, from the US Department of the Treasury (H15), and from Bloomberg. We find strong evidence that the resulting zero coupon bond yield volatility estimates as well as the correlation coefficients among spot and forward rates depend significantly on the data set. We observe relevant differences in economic terms when volatilities are used to price derivatives.
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Exposure to certain fungi can cause human illness. Fungi cause adverse human health effects through three specific mechanisms: generation of a harmful immune response (e.g., allergy or hypersensitivity pneumonitis); direct infection by the fungal organism; by toxic-irritant effects from mold byproducts, such as mycotoxins. In Portugal there is an increasingly industry of large facilities that produce whole chickens for domestic consumption and only few investigations have reported on fungal contamination of the poultry litter. The material used for poultry litter is varied but normally can be constitute by: pine shavings; sawdust of eucalyptus; other types of wood; peanut; coffee; sugar cane; straw; hay; grass; paper processed. Litter is one of the most contributive factors to fungal contamination in poultries. Spreading litter is one of the tasks that normally involve higher exposure of the poultry workers to dust, fungi and their metabolites, such as VOC’s and mycotoxins. After being used and removed from poultries, litter is ploughed into agricultural soils, being this practice potentially dangerous for the soil environment, as well for both humans and animals. The goal of this study was to characterize litter’s fungal contamination and also to report the incidence of keratinophilic and toxigenic fungi.
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Mestrado em Intervenção Sócio-Organizacional na Saúde - Área de especialização: Qualidade e Tecnologias da Saúde.
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We discuss existence and multiplicity of positive solutions of the Dirichlet problem for the quasilinear ordinary differential equation-(u' / root 1 - u'(2))' = f(t, u). Depending on the behaviour of f = f(t, s) near s = 0, we prove the existence of either one, or two, or three, or infinitely many positive solutions. In general, the positivity of f is not required. All results are obtained by reduction to an equivalent non-singular problem to which variational or topological methods apply in a classical fashion.
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Although numerous studies have been conducted on microbial contaminants associated with various stages related to poultry and meat products processing, only a few reported on fungal contamination of poultry litter. The goals of this study were to (1) characterize litter fungal contamination and (2) report the incidence of keratinophilic and toxigenic fungi presence. Seven fresh and 14 aged litter samples were collected from 7 poultry farms. In addition, 27 air samples of 25 litters were also collected through impaction method, and after laboratory processing and incubation of collected samples, quantitative colony-forming units (CFU/m3) and qualitative results were obtained. Twelve different fungal species were detected in fresh litter and Penicillium was the most frequent genus found (59.9%), followed by Alternaria (17.8%), Cladosporium (7.1%), and Aspergillus (5.7%). With respect to aged litter, 19 different fungal species were detected, with Penicillium sp. the most frequently isolated (42.3%), followed by Scopulariopsis sp. (38.3%), Trichosporon sp. (8.8%), and Aspergillus sp. (5.5%). A significant positive correlation was found between litter fungal contamination (CFU/g) and air fungal contamination (CFU/m3). Litter fungal quantification and species identification have important implications in the evaluation of potential adverse health risks to exposed workers and animals. Spreading of poultry litter in agricultural fields is a potential public health concern, since keratinophilic (Scopulariopsis and Fusarium genus) as well as toxigenic fungi (Aspergillus, Fusarium, and Penicillium genus) were isolated.
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In this paper we present a user-centered interface for a scheduling system. The purpose of this interface is to provide graphical and interactive ways of defining a scheduling problem. To create such user interface an evaluation-centered user interaction development method was adopted: the star life cycle. The created prototype comprises the Task Module and the Scheduling Problem Module. The first one allows users to define a sequence of operations, i.e., a task. The second one enables a scheduling problem definition, which consists in a set of tasks. Both modules are equipped with a set of real time validations to assure the correct definition of the necessary data input for the scheduling module of the system. The usability evaluation allowed us to measure the ease of interaction and observe the different forms of interaction provided by each participant, namely the reactions to the real time validation mechanism.
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This paper addresses the problem of energy resource scheduling. An aggregator will manage all distributed resources connected to its distribution network, including distributed generation based on renewable energy resources, demand response, storage systems, and electrical gridable vehicles. The use of gridable vehicles will have a significant impact on power systems management, especially in distribution networks. Therefore, the inclusion of vehicles in the optimal scheduling problem will be very important in future network management. The proposed particle swarm optimization approach is compared with a reference methodology based on mixed integer non-linear programming, implemented in GAMS, to evaluate the effectiveness of the proposed methodology. The paper includes a case study that consider a 32 bus distribution network with 66 distributed generators, 32 loads and 50 electric vehicles.