972 resultados para Constraint qualifications


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Esta dissertação tem como objetivo central o estudo da satisfação dos colaboradores com o sistema de recompensas de que beneficiam nas organizações onde trabalham. A lógica subjacente ao seu desenvolvimento privilegia, primeiramente, uma abordagem sobre os conceitos de sistema de recompensas e de satisfação e, consequentemente, as teorias que relacionam ambos os conceitos. Foi aplicado um inquérito por questionário a uma amostra de 94 colaboradores de duas cooperativas agrícolas localizadas na região Norte de Portugal. Foram testadas algumas hipóteses de estudo capazes de permitir caracterizar os sistemas de recompensas desenvolvidos nas cooperativas agrícolas objeto de estudo. A análise dos resultados permite concluir que: 1) é menor a satisfação com o sistema de recompensas entre os colaboradores do sexo feminino; 2) é maior a valorização atribuída à componente monetária do que à componente não monetária do sistema de recompensas; 3) a antiguidade na organização não influencia a satisfação dos colaboradores com o sistema de recompensas de que beneficiam; 4) predomina a componente monetária fixa no sistema de recompensas de ambas as cooperativas; 5) a maior satisfação com o sistema de recompensas de que beneficiam é encontrada entre os colaboradores com habilitações de nível superior e; 6) não foram encontradas diferenças na satisfação com o sistema de recompensas entre os colaboradores acima versus abaixo dos 45 anos. Baseado nestes resultados, na parte final desta dissertação são discutidas as principais implicações teóricas e práticas. Algumas limitações bem como sugestões para futura pesquisa são também apresentadas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação apresentada ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Gestão das Organizações, Ramo de Gestão de Empresas. Orientada por Prof. Doutor Manuel Salvador Gomes de Araújo

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper presents a modified Particle Swarm Optimization (PSO) methodology to solve the problem of energy resources management with high penetration of distributed generation and Electric Vehicles (EVs) with gridable capability (V2G). The objective of the day-ahead scheduling problem in this work is to minimize operation costs, namely energy costs, regarding he management of these resources in the smart grid context. The modifications applied to the PSO aimed to improve its adequacy to solve the mentioned problem. The proposed Application Specific Modified Particle Swarm Optimization (ASMPSO) includes an intelligent mechanism to adjust velocity limits during the search process, as well as self-parameterization of PSO parameters making it more user-independent. It presents better robustness and convergence characteristics compared with the tested PSO variants as well as better constraint handling. This enables its use for addressing real world large-scale problems in much shorter times than the deterministic methods, providing system operators with adequate decision support and achieving efficient resource scheduling, even when a significant number of alternative scenarios should be considered. The paper includes two realistic case studies with different penetration of gridable vehicles (1000 and 2000). The proposed methodology is about 2600 times faster than Mixed-Integer Non-Linear Programming (MINLP) reference technique, reducing the time required from 25 h to 36 s for the scenario with 2000 vehicles, with about one percent of difference in the objective function cost value.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Medical imaging is a powerful diagnostic tool. Consequently, the number of medical images taken has increased vastly over the past few decades. The most common medical imaging techniques use X-radiation as the primary investigative tool. The main limitation of using X-radiation is associated with the risk of developing cancers. Alongside this, technology has advanced and more centres now use CT scanners; these can incur significant radiation burdens compared with traditional X-ray imaging systems. The net effect is that the population radiation burden is rising steadily. Risk arising from X-radiation for diagnostic medical purposes needs minimising and one way to achieve this is through reducing radiation dose whilst optimising image quality. All ages are affected by risk from X-radiation however the increasing population age highlights the elderly as a new group that may require consideration. Of greatest concern are paediatric patients: firstly they are more sensitive to radiation; secondly their younger age means that the potential detriment to this group is greater. Containment of radiation exposure falls to a number of professionals within medical fields, from those who request imaging to those who produce the image. These staff are supported in their radiation protection role by engineers, physicists and technicians. It is important to realise that radiation protection is currently a major European focus of interest and minimum competence levels in radiation protection for radiographers have been defined through the integrated activities of the EU consortium called MEDRAPET. The outcomes of this project have been used by the European Federation of Radiographer Societies to describe the European Qualifications Framework levels for radiographers in radiation protection. Though variations exist between European countries radiographers and nuclear medicine technologists are normally the professional groups who are responsible for exposing screening populations and patients to X-radiation. As part of their training they learn fundamental principles of radiation protection and theoretical and practical approaches to dose minimisation. However dose minimisation is complex – it is not simply about reducing X-radiation without taking into account major contextual factors. These factors relate to the real world of clinical imaging and include the need to measure clinical image quality and lesion visibility when applying X-radiation dose reduction strategies. This requires the use of validated psychological and physics techniques to measure clinical image quality and lesion perceptibility.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The aim of this report is to highlight the importance of foresight exercises as a necessary tool to help the decision makers, allowing through projections and identification of the main trends, the identification of the key variables of the process and which ones may have more influence in the process of evolution of societies. It will be presented some examples of prospective methods and also scenarios construction. One example is the European project WORKS (Work organization restructuring in the knowledge society) that pretend to built a set of scenarios about the possible evolution of work in Europe in a short, medium and long term, stressing the key variables that may have an important role in the process and their interconnections. Another exemple is the report ‘Future skill needs in Europe’ prepared in 2008 by Cedefop, that presents data about the future development of employment by industry, occupation and qualification by 2015.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The clothing sector in Portugal is still seen, in many aspects as a traditional sector with some average characteristics, such as: low level of qualifications, less flexible labour legislation and stronger unionisation, very low salaries and low capability of investment in innovation and new technology. Is, nevertheless, a very important sector in terms of labour market, with increased weight in the exporting structure. Globalisation and delocalisation are having a strong impact in the organisation of work and in occupational careers in the sector. With the pressure of global competitiveness in what concerns time and prices, very few companies are able to keep a position in the market without changes in organisation of work and workers. And those that can perform good responses to such challenges are achieving a better economical stability. The companies have found different ways to face this reality according to size, capital and position. We could find two main paths: one where companies outsource a part or the entire production to another territory (for example, several manufacturing tasks), close and/or dismissal the workers. Other path, where companies up skilled their capacities investing, for example, in design, workers training, conception and introduction of new or original products. This paper will present some results from the European project WORKS – Work organisation and restructuring in the knowledge society (6th Framework Programme), focusing the Portuguese case studies in several clothing companies in what concern implications of global context for the companies in general and for the workers in particular, in a comparative analysis with some other European countries.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Educação Artística na especialização de Teatro na Educação

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Optimization problems arise in science, engineering, economy, etc. and we need to find the best solutions for each reality. The methods used to solve these problems depend on several factors, including the amount and type of accessible information, the available algorithms for solving them, and, obviously, the intrinsic characteristics of the problem. There are many kinds of optimization problems and, consequently, many kinds of methods to solve them. When the involved functions are nonlinear and their derivatives are not known or are very difficult to calculate, these methods are more rare. These kinds of functions are frequently called black box functions. To solve such problems without constraints (unconstrained optimization), we can use direct search methods. These methods do not require any derivatives or approximations of them. But when the problem has constraints (nonlinear programming problems) and, additionally, the constraint functions are black box functions, it is much more difficult to find the most appropriate method. Penalty methods can then be used. They transform the original problem into a sequence of other problems, derived from the initial, all without constraints. Then this sequence of problems (without constraints) can be solved using the methods available for unconstrained optimization. In this chapter, we present a classification of some of the existing penalty methods and describe some of their assumptions and limitations. These methods allow the solving of optimization problems with continuous, discrete, and mixing constraints, without requiring continuity, differentiability, or convexity. Thus, penalty methods can be used as the first step in the resolution of constrained problems, by means of methods that typically are used by unconstrained problems. We also discuss a new class of penalty methods for nonlinear optimization, which adjust the penalty parameter dynamically.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Constrained nonlinear optimization problems are usually solved using penalty or barrier methods combined with unconstrained optimization methods. Another alternative used to solve constrained nonlinear optimization problems is the lters method. Filters method, introduced by Fletcher and Ley er in 2002, have been widely used in several areas of constrained nonlinear optimization. These methods treat optimization problem as bi-objective attempts to minimize the objective function and a continuous function that aggregates the constraint violation functions. Audet and Dennis have presented the rst lters method for derivative-free nonlinear programming, based on pattern search methods. Motivated by this work we have de- veloped a new direct search method, based on simplex methods, for general constrained optimization, that combines the features of the simplex method and lters method. This work presents a new variant of these methods which combines the lters method with other direct search methods and are proposed some alternatives to aggregate the constraint violation functions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper presents a methodology to establish investment and trading strategies of a power generation company. These strategies are integrated in the ITEM-Game simulator in order to test their results when played against defined strategies used by other players. The developed strategies are focused on investment decisions, although trading strategies are also implemented to obtain base case results. Two cases are studied considering three players with the same trading strategy. In case 1, all players also have the same investment strategy driven by a market target share. In case 2, player 1 has an improved investment strategy with a target share twice of the target of players 2 and 3. Results put in evidence the influence of the CO2 and fuel prices in the company investment decision. It is also observed the influence of the budget constraint which might prevent the player to take the desired investment decision.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação apresentada para obtenção de Grau de Doutor em Bioquímica,Bioquímica Estrutural, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mestrado em Auditoria

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Informática

Relevância:

10.00% 10.00%

Publicador:

Resumo:

RESUMO - Num contexto em que a prestação de cuidados de Fisioterapia e Reabilitação é identificada como apresentando uma desigualdade e desajustamento da oferta regional superior à dos restantes cuidados de saúde, assim como uma falta de adequação dos preços praticados, perante as condições de oferta e procura actualmente existentes, o presente trabalho tem por objectivo investigar, no domínio do Desempenho, a influência do Financiamento na definição da prestação destes cuidados, tendo como pressuposto genérico que as decisões estratégicas e a reestruturação produtiva das organizações de saúde são condicionadas pelo sistema de preços. Considera-se que o actual sistema de Financiamento/Pagamento provoca um constrangimento na qualidade da resposta destes cuidados a dois níveis: um primeiro nível, ao colocar o pagamento no âmbito dos Meios Complementares de Diagnóstico e Terapêutica (MCDTs) a contratar pelo Serviço Nacional de Saúde, com isso determinando a configuração organizativa do sistema; um segundo nível de constrangimento que incide sobre as estruturas das organizações prestadoras, pela modelação que induz, nomeadamente a nível da sua produção. Na impossibilidade de tratar as duas dimensões do problema, pela falta de indicadores de desempenho deste sector, analisou-se, relativamente ao segundo nível de constrangimento, a produção de fisioterapia de três organizações que, potencialmente, teriam o mesmo o mesmo perfil de oferta por se enquadrarem num mesmo perfil de procura. Os resultados reflectem o pressuposto genérico do trabalho e abrem espaço para colocar como futura hipótese de investigação a razão da(s) causa(s) que poderão estar subjacentes à discrepância encontrada na média de tratamentos por sessão (duas vezes e meia) na produção das duas organizações que foi possível comparar.------------------- ABSTRACT - In a context where the provision of Physical Therapy and Rehabilitation care is identified as having a regional mismatch of supply and inequality above all the others health cares, and a lack of adequacy of prices in the current conditions of supply and demand, the present work has, as main purpose, to investigate, in the field of Performance, the Payment’s influence in shaping the provision of such health care. The general assumption tracking this analysis is that the strategic decisions on productive structure of health care organizations are influenced by the price systems. It is considered that the current Finance / Payment system causes two levels of constraints on the quality of such health care: a first constraint, as it putts its payment under the Supplementary Means of Diagnosis and Therapy (MCDTs), witch ends up establishing the organizational setup of the system; a second level of constraint by modelling the internal structure of these organizations. The lack of indicators characterizing the performance of this sector, addressed the present study to the second dimension, in witch was analysed the physical therapy production in three organizations that, potentially, would have the same profile of supply responding to similar characteristics of demand. The results reflect the above mentioned general assumption that supported the work, and leave an open space for future research, about the reason (s) that lay behind the discrepancy found between the average of treatments per session (two and a half times) in