An agent-based evolutionary approach for manufacturing system layout design

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresIn this thesis it is presented an approach to the problem of layout design for a manufacturing system, which is an important part of its design stage, given that it has influence in the system efficiency and, therefore, in its output rate and fault handling capabilities. The presented approach is based on a Genetic Algorithm (GA) that, by using information provided by the the user through an ontology file, and by using algorithms from graph-theory, designs the layout of a manufacturing system. The instances of the ontology represent manufacturing resources and their characteristics that, when they are being used by the algorithm, are encoded in chromosomes and in their genes. The algorithm begins with a number of chromosomes with low fitness which, with the directed evolution provided by the algorithm, that is restricted by the control parameters that might be tunned by the user, improve with the passing of the new generations. It is considered that the fittest solution is the one that connects, in order, all the resources required by the manufacturing plan, described in the ontology, without the occurrence of overlaps when the layout is constructed. The configuration presented by the transport system that handles parts and materials, in the selected layout, is only dependent on the available resources and on the fitness function used by the GA, being that the last cannot be changed by the user. This approach differs from others by positioning simultaneously all the components of the manufacturing system and not only workstations or transport system. The solution is directed to evolvable assembly systems, purpose for which it was implemented inside an agent, so it can be integrated in a Multiagent System (MAS) to be used in the control of a manufacturing system with minimal changes. Keywords: layout design, manufacturing system, multiagent system, ontology, genetic algorithm

Optimal choice between even- and uneven-aged forestry: the case of non-industrial private forest owners

An infinite-horizon discrete time model with multiple size-class structures using a transition matrix is built to assess optimal harvesting schedules in the context of Non-Industrial Private Forest (NIPF) owners. Three model specifications accounting for forest income, financial return on an asset and amenity valuations are considered. Numerical simulations suggest uneven-aged forest management where a rational forest owner adapts her or his forest policy by influencing the regeneration of trees or adjusting consumption dynamics depending on subjective time preference and market return rate dynamics on the financial asset. Moreover she or he does not value significantly non-market benefits captured by amenity valuations relatively to forest income.NSBE - UN

Predisposition assessment modelling

Dissertation submitted for obtaining the degree of Master in Environmental EngineeringOver the last decades outbreaks of the bark beetle Ips typographus (L.) assumed a high importance in forestry due to the economic losses caused, amounting to 3 million m3 the volume of wood damaged in 2009 in Austria. In natural systems, such events result from a dynamic interaction among several factors, the integrated analysis of which can depict the predisposition level of a stand, or site, to I. typographus outbreaks. The objective of this thesis was the development of a Predisposition Model for Rosalia Forest, located in the state (Land) of Vienna in Austria. Wind and snow storms are two of the main factors that lead to a higher level of risk, as high quantities of fallen timber become available, constituting a favourable breeding habitat for I. typographus communities to proliferate. Terrain and stand related data can be translated into parameters that are registered and studied using Geographic Information Systems, in order to obtain predisposition results to wind and snow damage and ultimately overall predisposition assessments to insect infestations. Stand and site related parameters from spatial and inventory data were analysed and scored according to an Assessment System previously formulated. In order to allow for different analysis and adjustments the Model was developed in a mask-like structure. Results on predisposition for the Rosalia Forest were spatially analysed and statistically processed. It was concluded that the majority of the stand area fell in the Medium predisposition class. This was due to the diversified age structure of the stand as well as to a relatively low proportion of the host species Picea abies present in this site. The model developed not only allows for the assessment of bark beetle predisposition according to an Assessment System based on an extensive compilation of literature, but can also be used as a working tool for further sites and scenarios by entities aiming at the management of the risk of I. typographus infestations

Oenological performance evaluation of yeast strains : implementation of an analytical method for biogenic amines in wines by HPLC-Fluorescence

Estágio realizado na Sogrape Vinhos, e orientado pela Eng. Cristina FernandesTese de Mestrado Integrado. Bioengenharia (Engenharia Biológica). Faculdade de Engenharia. Universidade do Porto. 201

Towards useful and usable interaction design tools: CanonSketch

Despite all the effort dedicated to bringing better User-Centered Design (UCD) tools to market, current studies show that the industry is still dominated by tools that do not support the activities and workstyles of designers. Also, there is a growing need for interaction design tools aimed at software engineers, a problem related to bringing usability into the software engineering processes. We propose a new workstyle model that can be effectively used to envision, design and evaluate a new generation of innovative interaction and software design tools, aimed at integrating usability and software engineering. We illustrate the effectiveness of our model by describing a new tool, called CanonSketch, that was built in order to support UCD in terms of the dimensions in our workstyle model. We also describe an evaluation study aimed at contrasting paper prototyping with our tool as well as the level of workstyle support.info:eu-repo/semantics/publishedVersio

Processo Especial de Revitalização (PER) : the process to recover financially distressed companies in Portugal

Este tese tem por objecto de estudo, o Processo Especial de Revitalização (PER). Sendo o PER, a mais relevante medida do Programa Revitalizar, programa este implementado pelo governo Português no ano de 2012 para combater a crise no sector empresarial português, com o objectivo de ser um mecanismo que permitisse às empresas a sua recuperação, satisfazendo os credores e mantendo postos de trabalho, foi importante perceber de que forma o sucesso de aprovação de um PER variava de empresa para empresa e quais os factores comuns que poderiam levar à aprovação, ou não, do PER. Com essa finalidade, foram analisados dois casos indivíduais. Mesmo sabendo da particularidade individual de cada caso, esta tese conclui sobre um conjunto de medidas comuns que podem beneficiar individualmente cada PER submetido no futuro, podendo assim melhorar ainda mais um mecanismo fundamental na ajuda da recuperação das empresas em Portugal.This thesis centers its study in PER. Being PER, the most relevant measure of Programa Revitalizar, a program introduced by the Portuguese government in 2012, with the objective of battling the economic crisis faced by the Portuguese companies, allowing these companies its financial recovery, therefore satisfying its creditors and maintaining job places, it was important to understand in which way did the approval of a PER changed from company to company and what were the common factors that could have led to an approval, or not, of the PER. With that goal on focus, two different individual cases were analyzed. Despite knowing about the individual particularity of each PER case, this thesis concludes about a range of common measures which might benefit individually future submitted cases, by this improving even more a crucial mechanism, responsible for the recuperation of failing companies in Portugal

UEFA : a successful pan-European organization during the cold war

The purpose of this paper is to analyse the formation of the Union Européenne de Football / European Football Association (UEFA) in the mid-1950s and its evolution during the period of the cold war. Post-World War II Europe was characterized for its division into two zones from an economic and political point of view. Countries from the two zones met in international organizations at the world level and created separate specifically European organizations for cooperation in several economic, political and cultural fields. However, there was an almost complete absence of specifically pan-European organizations bringing together countries from the two zones. The only significant exception was UEFA, which, from the mid-1950s onwards, succeeded in organizing regular football competitions between national and club teams from the whole continent without any significant problems, regardless of the different economic and political systems. This paper will discuss the reasons for such a remarkable achievement.info:eu-repo/semantics/publishedVersio

Understanding what impacts the purchase intention for private label brands : effects of quality, value, loyalty, promotions and involvement, among Portuguese consumers

This thesis aims to understand what variables mostly impact the purchase intention for Private Label brands, and if such impact changes with the introduction of product involvement as a moderator effect. Specifically, the goal is to study four different categories, which differ in their involvement level, through a questionnaire based on five constructs, four of which were used in previous research, one created by the author. The information is then used to estimate linear regression models, to understand the relative impact of each of these variables on the purchase intent for private labels, of the product categories chosen. This study aims to provide information, to both retailers and national brand manufacturers, about what variables assume a more impactful role in the purchase intension, and for them to use this information as a strategic element to improve their performance in these categories, and to possibly extrapolate some of the findings to other categories. Results have shown that Quality (both its perceived level and its level of variability in a product category) in general remains as the most impactful variable. Besides Quality, Loyalty (to a specific private label and consequently retailer) and Promotions, also stand as significant variables. This means that retailers, essentially must improve the quality of their brands, in order place their brands closer to national brands, as a credible alternative.Esta tese tem como objetivo compreender quais as variáveis que afetam predominantemente a intenção de compra de produtos de marca própria, e se esse impacto se altera significativamente com a introdução do envolvimento com o produto, como efeito moderador. Especificamente, o objetivo é estudar quatro categorias diferentes, que diferem no seu nível de envolvimento, através de um questionário baseado em cinco constructos, quatro dos quais foram utilizados em pesquisas anteriores, um criado pelo autor. A informação obtida é então usada para estimar modelos de regressão linear, para entender o impacto relativo de cada uma dessas variáveis na intenção de compra de produtos de marca própria. Este estudo pretende fornecer informação, tanto para os retalhistas como para os fabricantes de marcas nacionais, sobre quais as variáveis que assumem um papel mais impactante na intenção de compra por produtos de marca própria, de modo a que eles usem estas informações como um elemento estratégico para melhorar seu desempenho nas categorias analisadas nesta tese, e possivelmente extrapolar algumas das conclusões para outras categorias. Os resultados mostraram que a Qualidade (o seu nível percebido e o seu nível de variabilidade numa categoria de produto) permanece, em geral, como a variável mais impactante. Além de Qualidade, Lealdade (para uma marca própria particular e, consequentemente, um retalhista) e Promoções, também se destacam como variáveis significativas. Isto significa que os retalhistas, essencialmente devem melhorar a qualidade das suas marcas, de modo a aproximá-las das marcas nacionais, constituindo assim uma alternativa credível