3,178 research outputs found

    Integrated facility location and capacity planning under uncertainty

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    We address a multi-period facility location problem with two customer segments having distinct service requirements. While customers in one segment receive preferred service, customers in the other segment accept delayed deliveries as long as lateness does not exceed a pre-specified threshold. The objective is to define a schedule for facility deployment and capacity scalability that satisfies all customer demands at minimum cost. Facilities can have their capacities adjusted over the planning horizon through incrementally increasing or reducing the number of modular units they hold. These two features, capacity expansion and capacity contraction, can help substantially improve the flexibility in responding to demand changes. Future customer demands are assumed to be unknown. We propose two different frameworks for planning capacity decisions and present a two-stage stochastic model for each one of them. While in the first model decisions related to capacity scalability are modeled as first-stage decisions, in the second model, capacity adjustments are deferred to the second stage. We develop the extensive forms of the associated stochastic programs for the case of demand uncertainty being captured by a finite set of scenarios. Additional inequalities are proposed to enhance the original formulations. An extensive computational study with randomly generated instances shows that the proposed enhancements are very useful. Specifically, 97.5% of the instances can be solved to optimality in much shorter computing times. Important insights are also provided into the impact of the two different frameworks for planning capacity adjustments on the facility network configuration and its total cost.publishersversionpublishe

    Controversies and consensus on environmental education and education for sustainable development

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    A Educação Ambiental a muito tempo vem se tornando um tema importante, sendo necessário o entendimento sobre os conceitos e tendências, nacionais e internacionais. Desse modo trazemos aqui uma revisão narrativa, construída a partir do mapeamento de artigos, livros e pesquisas, em base de periódicos nacionais internacionais, relacionados com a área de interesse, estudando-os e em seguida sumarizando-os e, por fim, confrontando os e, por fim, confrontando-os sob os aspectos relacionados aos conceitos, opiniões, paradigmas e visões. O intuito é fornecer um olhar atualizado sobre o tema, não necessariamente exaurindo, mas provocar a reflexão sobre as tendências que levam à melhor relação do ser humano para com o ambiente. Por fim traçamos um correlato entre a Educação Ambiental e a Educação para o Desenvolvimento Sustentável.Environmental Education has long been becoming an important theme, being necessary the understanding on the concepts and trends, national and international. In this way we bring here a narrative revision, built from the mapping of articles, books and research, based on national and international periodicals, related to the area of interest, studying them and then summarizing, confronting in the aspects related to concepts, opinions, paradigms and visions. The intention is to provide an up-to-date look at the subject, not necessarily exhausting, but to provoke the reflection on the tendencies that lead to the best relation of the human being to the environment. Finally we draw a correlation between Environmental Education and Education for Sustainable Development.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), PortugalProjeto Estratégico da FCT: UID/CED/00317/2013. Fundos Nacionais através da FCT (Fundação para a Ciência e a Tecnologia) e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

    Cidades educadoras e gestão cultural : um estudo de caso no município da Lagoa-Açores

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    Mestrado, Património, Museologia e Desenvolvimento, 2 de Maio de 2017, Universidade dos Açores.É a partir do relatório Aprender a Ser, coordenado por Edgar Faure (1972) e publicado pela UNESCO, que surge o conceito de Cidade Educadora. Numa visão prospetiva da educação, Faure vem chamar a atenção para o capital educativo da cidade, fazendo a interligação entre educação-território. Em 1990, em Barcelona, decorre o I Congresso das Cidades Educadoras e é então que, partindo dos pressupostos de Faure, é redigida a Carta das Cidades Educadoras, com vinte princípios norteadores e subscrita, então, por 139 cidades. Numa cidade educadora, conceitos e linhas de atuação que vão ao encontro da educação permanente, de uma educação cultural e extensível a diversos equipamentos, de um projeto cultural e formativo da cidade, são aspetos fundamentais. Conscientes da importância de uma cidade assumir-se como uma escola a céu aberto para todos os cidadãos, da importância da identidade local e de uma gestão cultural e pedagógica municipal, este trabalho dedicou-se a estudar, numa primeira fase, o trinómio cidade-educação-cultura, de uma forma individual e interligada, centrando-se, à posteriori, nas cidades educadoras e nas suas políticas educativas e culturais. Esta componente teórica serviu de base para o estudo do Município da Lagoa (Açores), objeto de estudo desta dissertação. Neste estudo urgiu não só a necessidade de se efetuar uma investigação documental sobre o concelho (caraterização, enquadramento histórico, levantamento de potenciais recursos culturais e educativos, políticas municipais), como também se sentiu a necessidade de realizar um estudo quantitativo, através de um questionário estruturado que abrangeu 552 sujeitos, 62% a residir no concelho da Lagoa.ABSTRACT: It is from the report Learning to Be, coordinated by Edgar Faure (1972) and published by UNESCO that arises the concept of Educating City. In a prospective vision of education, Faure draw attention to the educational capital of the city, making the link between education and territory. In 1990, in Barcelona, follows the 1st International Congress of Educating Cities and it is then that, starting from the Faure assumptions, is drafted the Charter of Educating Cities, with twenty guiding principles and subscribed, then, by 139 cities. In an Educating City, concepts and lines of action that meet a permanent education, a cultural education extended to various facilities, a cultural and training project of the city, are fundamental aspects. Aware of the importance of a city to be assumed itself as a school open to all citizens, of the importance of local identity and a cultural and pedagogical municipal management, this work aims to study in a first phase, the trinomial city-education-culture, in an individual and interconnected way, focusing, in hindsight, on educational cities and their educational and cultural policies. This theoretical approach served as the basis for the study of the Lagoa Municipality (Azores), object of study of this dissertation In this study, it urged not only to make a documentary investigation about the municipality (characterization, historical framework, potential cultural and educational resources, municipal policies), but also we felt the need to make a quantitative study, using a structured questionnaire with 552 individual replies, 62% residing in the municipality of Lagoa

    Rastreio de Sintomas Psicopatológicos e de Bem-estar em Idosos sob Resposta Social na Ilha de Santa Maria, Açores

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    Um envelhecimento bem-sucedido tem como referência critérios sociais, psicológicos e fisiológicos. O presente trabalho tem como principal objetivo proceder ao rastreio dos sintomas psicopatológicos e de bem-estar numa amostra de idosos da ilha de Santa Maria, Açores. Foram inquiridos 54 idosos (15 do sexo masculino e 39 do sexo feminino) com idades compreendidas ente os 55 e 98 anos (M = 77,6 e Dp = 11,1) beneficiários de resposta social em duas instituições de Vila do Porto: o Recolhimento de Santa Maria Madalena (Residência e Apoio Domiciliário) e Santa Casa da Misericórdia (Lar e Residência). Os resultados obtidos foram comparados com dados preliminares do Projeto “Trajetórias de Envelhecimento” do ISMT. Constatou-se que a amostra de idosos da ilha de Santa Maria apresenta maior défice cognitivo, maior sintomatologia ansiosa e depressiva, menor satisfação com a vida e mais afetos negativos do que a amostra do ISMT. Não se verificam diferenças entre os sexos, sendo a idade e o nível de escolaridade as variáveis sociodemográficas que mais interferem na trajetória de envelhecimento. Os mais velhos e com menor escolaridade apresentam maior défice cognitivo. O aumento da idade está ainda relacionado com um aumento dos afetos negativos Estes resultados são preocupantes e sugerem a urgência de uma intervenção terapêutica planeada e especialmente desenhada para esta população, pois o facto de viverem numa ilha, com maior isolamento social e menor oferta de respostas sociais, parece prejudicar a sua saúde mental e a sua qualidade de vida

    Solving a signalized traffic intersection problem with an hyperbolic penalty function

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    Mathematical Program with Complementarity Constraints (MPCC) finds many applications in fields such as engineering design, economic equilibrium and mathematical programming theory itself. A queueing system model resulting from a single signalized intersection regulated by pre-timed control in traffic network is considered. The model is formulated as an MPCC problem. A MATLAB implementation based on an hyperbolic penalty function is used to solve this practical problem, computing the total average waiting time of the vehicles in all queues and the green split allocation. The problem was codified in AMPL

    Downward Wage Rigidities and Other Firms’ Responses to an Economic Slowdown: Evidence from a Survey of Colombian Firms

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    This paper uses a wage setting survey of 1,305 Colombian firms to explore the nature and sources of wage rigidities. This is the first study of a non-European emerging economy that uses evidence from a survey of firms to analyse this topic. The survey was carried out during the first half of 2009, when the Colombian economy was showing signs of a slowdown in economic activity and increasing unemployment. The sample is fully representative of the population under study. The results provide evidence of nominal and real downward wage rigidities in the country. The most important factor in not reducing base wages during an economic slowdown is to avoid the loss of more experienced and productive workers, which is related to the efficiency wage theory in its adverse selection version. In addition, ordered logit regressions were used to determine what factors are related to wage rigidities. The findings indicate that, in general, permanent contracts, workforce composition, labour intensity and the presence of collective agreements play an important role in explaining wage rigidities in the country.Wage rigidities, survey evidence, efficiency wages, Colombia, labour market, ordered logit. Classification JEL: C25, J30, J50

    Algumas configurações de didacticidade em chats como tarefa em aula de língua estrangeira

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    No inÌcio deste novo sÈculo continua a ser pertinente a afirmaÁ„o de Boaventura Sousa Santos, tantas vezes invocada nas v·rias ediÁıes de um seu Discurso sobr e as CiÍncias , porque vivemos, de facto, numa ìsociedade de comunicaÁ„o e interactivaî (Sousa Santos, 2002: 6). Contudo, n„o pretendemos aqui elaborar um discurso sobre as ciÍncias, nem t„o pouco discursar sobre a sociedade de comunicaÁ„o. O desafio que nos colocamos prende-se antes com a (re)descoberta da didacticidade

    Renal angiomyolipoma with renal vein thrombosis: an incidental finding

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    A 66-year-old female with history of endometrioid endometrial carcinoma was admitted to our institution with abdominal and pelvic pain. A CT scan revealed a mass within the right upper kidney with a tumour thrombus that extended through the right renal vein up to the point of confluence with the inferior vena cava (IVC). The imaging features of the mass strongly suggested a diagnosis of renal angiomyolipoma (AML) with renal vein thrombosis. The patient was proposed an open radical right nephrectomy with right renal thrombectomy for histopathological confirmation of the diagnosis of AML with extension to the right renal vein and preventing complications such as potentially fatal pulmonary thromboembolism. The implantation of a temporary IVC filter before surgery was recommended

    Numerical experiments with a modified regularization scheme for mathematical programs with complementarity constraints

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    On this paper we present a modified regularization scheme for Mathematical Programs with Complementarity Constraints. In the regularized formulations the complementarity condition is replaced by a constraint involving a positive parameter that can be decreased to zero. In our approach both the complementarity condition and the nonnegativity constraints are relaxed. An iterative algorithm is implemented in MATLAB language and a set of AMPL problems from MacMPEC database were tested
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