El conservadurismo, el secreto y las opciones de financiación de las pyme portuguesas

Doutoramento em Economia Financeira e Contabilidade

Symbolic dynamics and big bang bifurcation in Weibull-Gompertz-Fréchet's growth models

In this paper, motivated by the interest and relevance of the study of tumor growth models, a central point of our investigation is the study of the chaotic dynamics and the bifurcation structure of Weibull-Gompertz-Fréchet's functions: a class of continuousdefined one-dimensional maps. Using symbolic dynamics techniques and iteration theory, we established that depending on the properties of this class of functions in a neighborhood of a bifurcation point PBB, in a two-dimensional parameter space, there exists an order regarding how the infinite number of periodic orbits are born: the Sharkovsky ordering. Consequently, the corresponding symbolic sequences follow the usual unimodal kneading sequences in the topological ordered tree. We verified that under some sufficient conditions, Weibull-Gompertz-Fréchet's functions have a particular bifurcation structure: a big bang bifurcation point PBB. This fractal bifurcations structure is of the so-called "box-within-a-box" type, associated to a boxe ω1, where an infinite number of bifurcation curves issues from. This analysis is done making use of fold and flip bifurcation curves and symbolic dynamics techniques. The present paper is an original contribution in the framework of the big bang bifurcation analysis for continuous maps.

Increasing availability through maintainability growth using partial Multi Criteria Decision Making (pMCDM)

In the last decades considerations about equipments' availability became an important issue, as well as its dependence on components characteristics such as reliability and maintainability. This is particularly of outstanding importance if one is dealing with high risk industrial equipments, where these factors play an important and fundamental role in risk management when safety or huge economic values are in discussion. As availability is a function of reliability, maintainability, and maintenance support activities, the main goal is to improve one or more of these factors. This paper intends to show how maintainability can influence availability and present a methodology to select the most important attributes for maintainability using a partial Multi Criteria Decision Making (pMCDM). Improvements in maintainability can be analyzed assuming it as a probability related with a restore probability density function [g(t)].

A method to analyse the alignment of core values in collaborative networked organisations

Since collaborative networked organisations are usually formed by independent and heterogeneous entities, it is natural that each member holds his own set of values, and that conflicts among partners might emerge because of some misalignment of values. In contrast, it is often stated in literature that the alignment between the value systems of members involved in collaborative processes is a prerequisite for successful co-working. As a result, the issue of core value alignment in collaborative networks started to attract attention. However, methods to analyse such alignment are lacking mainly because the concept of 'alignment' in this context is still ill defined and shows a multifaceted nature. As a contribution to the area, this article introduces an approach based on causal models and graph theory for the analysis of core value alignment in collaborative networks. The potential application of the approach is then discussed in the virtual organisations' breeding environment context.

Computing the phase diagram of binary mixtures: A patchy particle case study

We investigate the phase behaviour of 2D mixtures of bi-functional and three-functional patchy particles and 3D mixtures of bi-functional and tetra-functional patchy particles by means of Monte Carlo simulations and Wertheim theory. We start by computing the critical points of the pure systems and then we investigate how the critical parameters change upon lowering the temperature. We extend the successive umbrella sampling method to mixtures to make it possible to extract information about the phase behaviour of the system at a fixed temperature for the whole range of densities and compositions of interest. (C) 2013 AIP Publishing LLC.

Análise de risco em organizações: caso de estudo

Dissertação Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica no perfil de Manutenção e Produção

Leilões combinados

Mestrado em Controlo de Gestão e dos Negócios

Complex variable positive definite functions

In this paper we develop an appropriate theory of positive definite functions on the complex plane from first principles and show some consequences of positive definiteness for meromorphic functions.

A diferença evolutiva de alunos do projeto Orquestra Geração e das escolas vocacionais de música: a importância dos agentes de motivação

Resumo I (Prática Pedagógica) - Nesta secção do relatório de estágio pretende-se expor e caracterizar todos os elementos referentes à prática pedagógica, integrada no estágio, que ocorreu em parceria com a Escola de Música do Conservatório Nacional (EMCN) e o Projecto Orquestra Geração realizado no ano letivo de 2014/2015. Este tem por objetivo, a abordagem dos aspetos pedagógicos, as metodologias de ensino, a eficácia do trabalho, a motivação e os agentes motivacionais. Para a elaboração deste relatório, foram observados e devidamente analisados três alunos de forma peculiar. Porém, é de realçar que um dos intervenientes pertencia à EMCN e as aulas apenas eram observadas. Ao longo do ano letivo foram elaborados individualmente para cada aluno, vinte e dois planos de aula e ainda realizadas três gravações de aulas que foram vistas pelo professor orientador. À posteriori serão caraterizadas as duas entidades que fizeram parceria, contribuindo para a possível realização do relatório de estágio. Será abordada a sua contextualização histórica, os parâmetros de ensino, o contexto sociocultural. De seguida, será apresentada a caraterização dos três alunos, abordando nomeadamente, o seu meio envolvente, os métodos de estudo e a evolução motora, expressiva e auditiva. Serão analisadas e descritas algumas das práticas de ensino, desenvolvidas quer ao longo das aulas individuais, quer da observação das gravações e da análise constante dos planos de aulas e das planificações. Para finalizar o relatório de estágio, será elaborada uma reflexão crítica, acerca do desempenho como docente e respetiva prática pedagógica trabalhada com os alunos.