863 resultados para Job Demands-Resources model
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A great number of low-temperature geothermal fields occur in Northern-Portugal related to fractured rocks. The most important superficial manifestations of these hydrothermal systems appear in pull-apart tectonic basins and are strongly conditioned by the orientation of the main fault systems in the region. This work presents the interpretation of gravity gradient maps and 3D inversion model produced from a regional gravity survey. The horizontal gradients reveal a complex fault system. The obtained 3D model of density contrast puts into evidence the main fault zone in the region and the depth distribution of the granitic bodies. Their relationship with the hydrothermal systems supports the conceptual models elaborated from hydrochemical and isotopic water analyses. This work emphasizes the importance of the role of the gravity method and analysis to better understand the connection between hydrothermal systems and the fractured rock pattern and surrounding geology. (c) 2013 Elsevier B.V. All rights reserved.
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Dissertação de Mestrado em Ciências Económicas e Empresariais.
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Dissertação de Mestrado em Ambiente, Saúde e Segurança.
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Mestrado em Auditoria
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Trabalho de Projeto para obtenção do grau de Mestre em Engenharia Informática e de Computadores
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In this paper we consider a differentiated Stackelberg model, when the leader firm engages in an R&D process that gives an endogenous cost-reducing innovation. The aim is to study the licensing of the cost-reduction by a two-part tariff. By using comparative static analysis, we conclude that the degree of the differentiation of the goods plays an important role in the results. We also do a direct comparison between our model and Cournot duopoly model.
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Nas últimas décadas assistimos a transformações económicas, tecnológicas, políticas e sociais, que influenciaram diretamente o modo de pensar e agir nas organizações. O conceito de competências, com uma valorização crescente, surge como uma alternativa à abordagem da gestão de recursos humanos por funções, respondendo aos desafios atuais do mercado: necessidade de flexibilidade, de adaptação a mudanças contínuas, exigências crescentes do mercado e competitividade das organizações nesse mercado. A área da saúde, e concretamente a profissão de Enfermagem também tem evoluído, surgindo em 2009, uma nova forma de operacionalizar a carreira destes profissionais. No que diz respeito aos enfermeiros com funções de gestão, o conteúdo funcional está descrito, contudo, não existe uma definição clara das competências requeridas para estes profissionais. Este trabalho de investigação, de cariz exploratório, utilizando uma metodologia qualitativa, pretendeu propor uma estratégia de definição de um modelo de competências para os enfermeiros com funções de gestão em Portugal. Para isso, definimos categorias de competências, através da análise da literatura e da legislação. Seguiu-se a realização de entrevistas a um painel de doze peritos, e uma análise de conteúdo dos dados (categorização do tipo misto). Procedemos a uma comparação da recolha empírica de competências com as da recolha teórica, e definimos uma lista de 10 competências para as funções de gestão dos enfermeiros: Competências Técnicas de Gestão; Competências Interpessoais; Comunicação; Gestão de Recursos Humanos; Pensamento Crítico; Conhecimento de Políticas de Saúde; Competências Técnicas de Enfermagem; Organização e Planeamento; Trabalho de Equipa; Preocupação pela Qualidade. De forma a complementar o estudo, pretendemos identificar a perceção das lacunas de competências nos enfermeiros com funções de gestão, e identificar os processos de desenvolvimento de competências considerados mais relevantes para estes profissionais. As lacunas identificadas nas competências dos atuais enfermeiros com funções de gestão, face às mais valorizadas, são reduzidas e dispersas, pelo que consideramos pouco significativas. A forma de desenvolvimento de competências mais valorizado pelo painel de peritos foi a formação (académica e em contexto profissional). Foi também realçada a importância do empenho individual neste processo, assim como a avaliação de competências antes dos enfermeiros assumirem funções de gestão.Consideramos que esta investigação traz contributos quer para a literatura da Gestão por Competências, quer para a literatura da definição de competências das funções dos enfermeiros com funções de gestão, quer para a profissão de enfermagem, (nomeadamente, para as funções de gestão dos enfermeiros), quer para o próprio SNS, já que faz algumas propostas e sugestões para a evolução das práticas de gestão de pessoas.
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Demands for functionality enhancements, cost reductions and power savings clearly suggest the introduction of multiand many-core platforms in real-time embedded systems. However, when compared to uni-core platforms, the manycores experience additional problems, namely the lack of scalable coherence mechanisms and the necessity to perform migrations. These problems have to be addressed before such systems can be considered for integration into the realtime embedded domain. We have devised several agreement protocols which solve some of the aforementioned issues. The protocols allow the applications to plan and organise their future executions both temporally and spatially (i.e. when and where the next job will be executed). Decisions can be driven by several factors, e.g. load balancing, energy savings and thermal issues. All presented protocols are analytically described, with the particular emphasis on their respective real-time behaviours and worst-case performance. The underlying assumptions are based on the multi-kernel model and the message-passing paradigm, which constitutes the communication between the interacting instances.
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Preemptions account for a non-negligible overhead during system execution. There has been substantial amount of research on estimating the delay incurred due to the loss of working sets in the processor state (caches, registers, TLBs) and some on avoiding preemptions, or limiting the preemption cost. We present an algorithm to reduce preemptions by further delaying the start of execution of high priority tasks in fixed priority scheduling. Our approaches take advantage of the floating non-preemptive regions model and exploit the fact that, during the schedule, the relative task phasing will differ from the worst-case scenario in terms of admissible preemption deferral. Furthermore, approximations to reduce the complexity of the proposed approach are presented. Substantial set of experiments demonstrate that the approach and approximations improve over existing work, in particular for the case of high utilisation systems, where savings of up to 22% on the number of preemption are attained.
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This paper presents the Genetic Algorithms (GA) as an efficient solution for the Okumura-Hata prediction model tuning on railways communications. A method for modelling the propagation model tuning parameters was presented. The algorithm tuning and validation were based on real networks measurements carried out on four different propagation scenarios and several performance indicators were used. It was shown that the proposed GA is able to produce significant improvements over the original model. The algorithm developed is currently been used on real GSM-R network planning process for an enhanced resources usage.
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This paper examines the job quality in Europe. It is based on the results of the Fourth European Foundation Survey on working conditions covering different dimensions including work organisation, job content, autonomy at work, aspects of worker dignity, working time and work-life balance, working conditions and safety in the workplace. The results point to the existence of great diversity in the job quality across Europe and the north-south divide. The job quality differences are related to the variety of social and institutional contexts. The countries of Southern Europe, with their social and institutional contexts falling within the scope of the Mediterranean model, generally present indicators below the European average contrasting Nordic countries having the best job quality indicators.
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The process of resources systems selection takes an important part in Distributed/Agile/Virtual Enterprises (D/A/V Es) integration. However, the resources systems selection is still a difficult matter to solve in a D/A/VE, as it is pointed out in this paper. Globally, we can say that the selection problem has been equated from different aspects, originating different kinds of models/algorithms to solve it. In order to assist the development of a web prototype tool (broker tool), intelligent and flexible, that integrates all the selection model activities and tools, and with the capacity to adequate to each D/A/V E project or instance (this is the major goal of our final project), we intend in this paper to show: a formulation of a kind of resources selection problem and the limitations of the algorithms proposed to solve it. We formulate a particular case of the problem as an integer programming, which is solved using simplex and branch and bound algorithms, and identify their performance limitations (in terms of processing time) based on simulation results. These limitations depend on the number of processing tasks and on the number of pre-selected resources per processing tasks, defining the domain of applicability of the algorithms for the problem studied. The limitations detected open the necessity of the application of other kind of algorithms (approximate solution algorithms) outside the domain of applicability founded for the algorithms simulated. However, for a broker tool it is very important the knowledge of algorithms limitations, in order to, based on problem features, develop and select the most suitable algorithm that guarantees a good performance.
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Most definitions of virtual enterprise (VE) incorporate the idea of extended and collaborative outsourcing to suppliers and subcontractors in order to achieve a competitive response to market demands (Webster, Sugden, & Tayles, 2004). As suggested by several authors (Browne & Zhang, 1999; Byrne, 1993; Camarinha-Matos & Afsarmanesh, 1999; Cunha, Putnik, & Ávila, 2000; Davidow & Malone, 1992; Preiss, Goldman, & Nagel, 1996), a VE consists of a network of independent enterprises (resources providers) with reconfiguration capability in useful time, permanently aligned with the market requirements, created to take profit from a specific market opportunity, and where each participant contributes with its best practices and core competencies to the success and competitiveness of the structure as a whole. Even during the operation phase of the VE, the configuration can change, to assure business alignment with the market demands, traduced by the identification of reconfiguration opportunities and continuous readjustment or reconfiguration of the VE network, to meet unexpected situations or to keep permanent competitiveness and maximum performance (Cunha & Putnik, 2002, 2005a, 2005b).
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The teaching-learning process is increasingly focused on the combination of the paradigms “learning by viewing” and “learning by doing.” In this context, educational resources, either expository or evaluative, play a pivotal role. Both types of resources are interdependent and their sequencing would create a richer educational experience to the end user. However, there is a lack of tools that support sequencing essentially due to the fact that existing specifications are complex. The Seqins is a sequencing tool of digital resources that has a fairly simple sequencing model. The tool communicates through the IMS LTI specification with a plethora of e-learning systems such as learning management systems, repositories, authoring and evaluation systems. In order to validate Seqins we integrate it in an e-learning Ensemble framework instance for the computer programming learning.
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Tese de Doutoramento em Sociologia da Comunicação