23 resultados para Continuous functions
em Instituto Politécnico do Porto, Portugal
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IRMA International Conference under the theme Managing Worldwide Operations and Communications with Information Technology, May 19-23, Vancouver, British Columbia, Canada
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In this work three natural waste materials containing chitin were used as adsorbents for textile dyestuffs, namely the Anodonta (Anodonta cygnea) shell, the Sepia (Sepia officinalis) and the Squid (Loligo vulgaris) pens. The selected dyestuffs were the Cibacron green T3G-E (CI reactive green 12), and the Solophenyl green BLE 155% (CI direct green 26), both from CIBA, commonly used in cellulosic fibres dyeing, the most used fibres in the textile industry. Batch equilibrium studies showed that the materials’ adsorption capacities increase after a simple and inexpensive chemical treatment, which increases their porosity and chitin relative content. Kinetic studies suggested the existence of a high internal resistance in both systems. Fixed bed column experiments performed showed an improvement in adsorbents’ behaviour after chemical treatment. However, in the column experiments, the biodegradation was the main mechanism of dyestuff removal, allowing the materials’ bioregeneration. The adsorption was strongly reduced by the pore clogging effect of the biomass. The deproteinised Squid pen (grain size 0.500–1.41 mm) is the adsorbent with highest adsorption capacity (0.27 and 0.037 g/g, respectively, for the reactive and direct dyestuffs, at 20ºC), followed by the demineralised Sepia pen and Anodonta shell, behaving like pure chitin in all experiments, but showing inferior performances than the granular activated carbon tested in the column experiments.
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Screening of topologies developed by hierarchical heuristic procedures can be carried out by comparing their optimal performance. In this work we will be exploiting mono-objective process optimization using two algorithms, simulated annealing and tabu search, and four different objective functions: two of the net present value type, one of them including environmental costs and two of the global potential impact type. The hydrodealkylation of toluene to produce benzene was used as case study, considering five topologies with different complexities mainly obtained by including or not liquid recycling and heat integration. The performance of the algorithms together with the objective functions was observed, analyzed and discussed from various perspectives: average deviation of results for each algorithm, capacity for producing high purity product, screening of topologies, objective functions robustness in screening of topologies, trade-offs between economic and environmental type objective functions and variability of optimum solutions.
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A sociedade moderna encontra-se numa evolução progressiva e constante no que respeita às novas tecnologias. Independentemente da área de conhecimento, é de senso comum, que cada vez mais é necessária formação sólida, sendo fundamental a preparação e a consolidação das futuras gerações na utilização das novas tecnologias. As plataformas de e-learning são hoje em dia uma realidade mais que afirmada, e com aplicação em todos os sectores de actividade. A área da saúde não foge à regra, verificando-se que os seus profissionais evidenciam falta de disponibilidade para participação nas formações presenciais, fundamentais para o seu processo de formação contínua (LLL – Long Liffe Learning). Estes profissionais necessitam de estar continuamente actualizados, de forma a melhor poderem contribuir para o desempenho das suas funções, como o aconselhamento dos utentes, acompanhamento de doentes crónicos, uso correcto dos medicamentos, entre outros. O presente trabalho pretende implementar em ambiente hospitalar o modelo de formação à distância em regime de e-learning ou b-learning, identificando potenciais vantagens e constrangimentos inerentes ao processo. Para o efeito, será utilizada a plataforma MEDUCA criada pelo GILT-ISEP e baseada em Moodle, como uma plataforma destinada á formação para profissionais da área da Saúde. Esta dissertação apresenta uma investigação sobre a implementação da dita plataforma em ambiente hospitalar. Esta dissertação apresenta todo o estudo/trabalho desenvolvido para a implementação da plataforma MEDUCA nalgumas entidades contactadas da área da saúde. Espera-se que esta ferramenta ofereça uma alternativa interactiva de educação e aprendizagem, visando melhorar constantemente o nível formativo de cada profissional de saúde.
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We introduce a new wavelet transform within the framework of the local fractional calculus. An illustrative example of local fractional wavelet transform is also presented.
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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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In this paper, the fractional Fourier transform (FrFT) is applied to the spectral bands of two component mixture containing oxfendazole and oxyclozanide to provide the multicomponent quantitative prediction of the related substances. With this aim in mind, the modulus of FrFT spectral bands are processed by the continuous Mexican Hat family of wavelets, being denoted by MEXH-CWT-MOFrFT. Four modulus sets are obtained for the parameter a of the FrFT going from 0.6 up to 0.9 in order to compare their effects upon the spectral and quantitative resolutions. Four linear regression plots for each substance were obtained by measuring the MEXH-CWT-MOFrFT amplitudes in the application of the MEXH family to the modulus of the FrFT. This new combined powerful tool is validated by analyzing the artificial samples of the related drugs, and it is applied to the quality control of the commercial veterinary samples.
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This technical report describes the PDFs which have been implemented to model the behaviours of certain parameters of the Repeater-Based Hybrid Wired/Wireless PROFIBUS Network Simulator (RHW2PNetSim) and Bridge-Based Hybrid Wired/Wireless PROFIBUS Network Simulator (BHW2PNetSim).
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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.
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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.
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Towpregs based on different fibres and thermoplastic matrices were processed for highly demanding and more commercial applications by different composite processing technologies. In the technologies used, compression moulding and pultrusion, the final composite pr ocessing parameters were studied in order to obtain composites with adequate properties at industrial compatible production rates. The produced towpregs were tested to verify its polymer content and degree of impregnation. The obtained results have shown t hat the coating line enabled to produce, with efficiency and industrial scale speed rates, thermoplastic matrix towpregs that may be used to manufacture composites for advanced and larger volume commercial markets.
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Not just with the emergence but also with the growing of the electronic market, that is, the growth of online suppliers of services and products and Internet users (potential consumers), the necessary conditions to the affirmation of the agile/virtual enterprises (A/VE) as a present and future enterprise organizational model are created. In this context, it is our understanding that the broker may have an important role in its development, namely, if the broker performs functions for the A/VE with better efficacy and efficiency. In this article, we will present first a revision of the broker’s models in a structured form. We present a taxonomy of possible broker’s functions for the broker’s actuation near the A/VE and then the classification of the literature broker’s models. This classification will permit an analysis of a broker’s model and establish a mainframe for our broker’s model according to the BM_Virtual Enterprise Architecture Reference Model (BM_VEARM).
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In this paper we address the problem of computing multiple roots of a system of nonlinear equations through the global optimization of an appropriate merit function. The search procedure for a global minimizer of the merit function is carried out by a metaheuristic, known as harmony search, which does not require any derivative information. The multiple roots of the system are sequentially determined along several iterations of a single run, where the merit function is accordingly modified by penalty terms that aim to create repulsion areas around previously computed minimizers. A repulsion algorithm based on a multiplicative kind penalty function is proposed. Preliminary numerical experiments with a benchmark set of problems show the effectiveness of the proposed method.
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Mestrado em Engenharia Mecânica - Especialização em Gestão Industrial