Biblioteca Digital

Actualmente, a indústria dos moldes para responder às exigências do mercado procura diversificar os seus mercados, apostando em produtos diferenciados e de valor acrescentado. Foi neste sentido que se desenvolveu o projecto de concepção e fabrico de vasos biodegradáveis para germinação de plantas. O objectivo deste artigo de investigação passa pela concepção e desenvolvimento de um vaso para germinação de plantas produzido em material biodegradável. A validação do projecto desenvolvido para uma peça de paredes finas em material biodegradável, foi realizada através da fabricação da ferramenta (molde) e o processamento de peças (vasos biodegradáveis). Este estudo demonstrou-se promissor como pilar de apoio para o desenvolvimento de futuros produtos em materiais biodegradáveis de paredes finas, obtidos pelo processo de injecção de termoplásticos. Os resultados alcançados permitiram validar o processo desenvolvido, bem como o produto obtido de paredes finas em material biodegradável, que neste caso foi um vaso biodegradável para germinação de plantas.

We show that the Bi-Layer Graphene allows the control of its electronic gap under an applied voltage.

In this work we present a vectorized Matlab algorithm for the decomposition of an endomap into its finite orbits.

We give two examples of application of a vectorized programming paradigm: binary addition and cycle decomposition of directed graphs.

Well understood in economics, accounting, finance, and legal research, transfer pricing has rarely been comprehensively explored in organization management literature. This paper explores some theoretical explanations of transfer pricing within multidivisional firms drawing insights from various organizational theories - primarily institutional theory, transaction cost economics, and social networks - to develop a conceptual model of transfer pricing. This model focuses on the nature of multidivisional firms' internal transfers, internal and external technological environments, and internal and external social environments. We highlight the importance of transfer pricing as a key strategic dimension to understand intra-firm flows and their associated costs.

This paper investigates theoretically the importance and impact of the international entrepreneurial firms’ (IEFs) social networks on selected firms’ strategies. We focus specifically on some core attributes of IEFs and the impact of social networks on such strategies as the choice of the foreign markets to operate and the foreign entry modes. The social networks are a major driver of the internationalization from inception and help in overcoming a variety of physical and social resource limitations as well as transactional hazards. We conclude that it is likely that both some fundamental characteristics of the IEFs and those of the foreign markets entered account for these firms reliance on their social networks.

Recent research has theorized on the composition of firms' business networks but has not empirically examined business networks in transition economies may vary for different firms. In this study, using firm level data from twenty six transition economies collected by the World Bank and the EBRD in 1999-2000, we conduct a set of logistic regression models to investigate the composition of small and large firms' business networks. The results show that, in contrast to smaller firms, larger firms are more likely to have formal business relationships, and relationships with national and foreign financial institutions, government, and foreign firms. In addition, in a subgroup analysis of seven transition economies we show that the composition of the firms' business networks varies substantially across countries but that the government is still a dominant client. Furthermore, we found a large variation on firms' reliance on informal ties and the extent to which firms exchange with foreign firms.

This article discusses the impact of political culture on the exploitation-exploration internationalization strategies of firms. In particular, we propose that four dimensions of political culture – nationalism, internationalism, patriotism, and cosmopolitanism – influence firms’ willingness to explore new opportunities and/or to exploit existing products and capabilities across borders. We suggest that firms in nationalist home country cultures are more likely to pursue exploitation strategies, whereas those in cosmopolitan cultures are more likely to pursue exploration strategies. For firms embedded in patriotic or internationalist cultures, a mix of exploitation and exploration internationalization strategies might be the more likely choice. We conclude that these political culture dimensions may be useful to understand and predict many firm-level strategic choices, such as the type of internationalization strategy pursued, the choice of foreign entry mode and location, and decisions concerning the management of foreign subsidiaries.

Well understood in economics, accounting, finance, and legal research, transfer pricing has rarely been comprehensively explored in organization management literature. This paper explores some theoretical explanations of transfer pricing within multidivisional firms drawing insights from various organizational theories – primarily institutional theory, transaction cost economics, and social networks – to develop a conceptual model of transfer pricing. This model focuses on the nature of multidivisional firms’ internal transfers, internal and external technological environments, and internal and external social environments. We highlight the importance of transfer pricing as a key strategic dimension to understand intra-firm flows and their associated costs.

In this paper, we propose a dynamic model of entrepreneurial firms’ dependence on networks. First we argue that five characteristics of entrepreneurial firms result in their high dependence on networks; these five characteristics include entrepreneurial orientation, central role of the entrepreneur, resource constraints, pursuit of flexibility, and niche market focus. We then examine how entrepreneurial firms’ growth is accompanied by the evolution of these five characteristics leading to a shift in the mode through which entrepreneurial firms construct and deploy their networks. In particular, we examine the composition and the stability of entrepreneurial firms’ networks. This paper contributes to building a more integrative theory of entrepreneurship.

In this study, using firm level data from twenty six transition economies collected by the World Bank and the EBRD in 1999-2000, we conduct a set of logistic regression models to investigate the composition of small and large firms’ business networks. The results show that, in contrast to smaller firms, larger firms are more likely to have formal business relationships, and relationships with national and foreign financial institutions, government, and foreign firms. In addition, in a subgroup analysis of seven transition economies we show that the composition of the firms’ business networks varies substantially across countries but that the government is still a dominant client. Furthermore, we found a large variation on firms’ reliance on informal ties and the extent to which firms exchange with foreign firms.

Paradigmatic analysis consists in the segmentation of a musical piece through the identification of relations between different parts of the piece, and the classification of the identified segments into categories. In this paper we describe how a genetic programming system can be used to make the paradigmatic analysis of monophonic musical pieces, using a simple fitness function inspired in the Kolmogorov complexity estimation. We make use of automatically defined functions in order to represent segments. Relations are made explicit through the reuse of segments and the application of transformations to these segments.

We investigate aspects that control the Spatial Prisoner’s Dilemma game sensitivity to the synchrony rate of the model. Based on simulations done with the generalized proportional and the replicator dynamics transition rules, we conclude that the sensitivity of the game to the synchrony rate depends almost exclusively on the transition rule used to model the strategy update by the agents. We then identify the features of these transition rules that are responsible for the sensitivity of the game. The results show that the Spatial Prisoner’s Dilemma game becomes more and more sensitive for noise levels above a given noise threshold. Below this threshold, the game is robust to the noise level and its robustness even slightly grows, compared to the imitate the best strategy, if a small amount of noise is present in the strategy update process.

We argue that intermediate levels of asynchronism should be explored when one uses evolutionary games to model biological and sociological systems. Usually, only perfect synchronism and continuous asynchronism are used, assuming that it is enough to test the model under these two opposite update methods. We believe that biological and social systems lie somewhere between these two extremes and that we should inquire how the models used in these situations behave when the update method allows more than one element to be active at the same time but not necessarily all of them. Here, we use an update method called Asynchronous Stochastic Dynamics which allows us to explore intermediate levels of asynchronism and we apply it to the Spatial Prisoner’s Dilemma game. We report some results concerning the way the system changes its behaviour as the synchrony rate of the update method varies.

This paper describes a representation of plan cases as a structured set of goals and actions. These goals and actions are the unit pieces that form a case. These case pieces are related each other by hierarchical and temporal links (explanations) forming a tree-like network. We give importance not just to explicit links, i.e., links between case pieces which are concretely known, but also to implicit ones, i.e., possibly unknown links between case pieces. Each case piece is explained by antecedent links and explains other case pieces by consequent links. The retrieval of a case piece is mainly guided by its links and by its surrounding case pieces. Our concept of case piece usefulness is briefly explained. We discuss the benefit of reusing and directly accessing small case pieces from multiple cases for improving the Case-Based Reasoning (CBR) systems’ capability and efficiency to solve problems. We explain the importance of stepwise refinement in plan cases and also the role that temporal representation can take in the meaningful and coherent construction of planning problem solutions. An application in musical composition domain is presented. We also show how a musical composition task can be treated as a planning task.

We examine the influence of asynchronism in the Spatial Prisoner’s Dilemma game. Previous studies reported that less cooperation is achieved with the asynchronous version of the game than with the synchronous one. Here, we show that, in general, the opposite is the most common outcome. This conclusion is only possible because a larger number of scenarios was tested, namely, different interaction topologies, a transition rule that can be tuned to emulate different levels of determinism in the choice of the next strategy to be adopted and different rates of asynchronism. The influence of stochastic and deterministic periodic updating in the outcome of the system is also compared. We found that these two update disciplines lead basically to the same result. This is an important issue in the simulation of social and biological behavior.

The goal of this paper is to introduce a Computational Fluid Dynamics model to study the steady three-dimensional turbulent airflow pattern, with thermal buoyant effects, the heat transfer, the gas contaminant transport and the moist air transport into mechanical or natural ventilated spaces, with furniture and people. The calculations made use of a numerical procedure with solves the three-dimensional steady state equations for the conservation of mass, momentum, thermal energy and air contaminant transport, tanking account of the effects of buoyancy and airflow turbulence. In order to demonstrate its applicability, the code has been used to predict the thermal, the airflow pattern and the environment in an office ventilated room. Based on this predictions and on thermal comfort models it was possible to evaluate the thermal comfort.

A política nacional para o Ensino Superior integra, desde as últimas décadas do século XX, claros objetivos catalisadores do progresso tecnológico, social e cultural, capazes de identificar, interpretar e responder às instâncias reais do mundo atual. No intuito de responder aos desafios emergentes, sob ecos (mais ou menos) inflamados acerca das opções normativas, as instituições de ensino superior pugnaram pela eficácia dos mesmos enquanto resposta às dinâmicas económicas, bem como às exigências de competitividade e produtividade que passaram a reivindicar um novo patamar de qualificação profissional. A Aula incorpora um espaço privilegiado de construção coletiva do conhecimento na intersubjetividade dos seus atores. Invocar isoladamente o domínio cognitivo é um argumento parco para os propósitos que intenta. O processo de ensino-aprendizagem não se constitui de modo fragmentado ou dissociado das relações pessoais e afetivas. Neste domínio, a relação entre o Professor-Aluno é basilar na edificação do ser humano/cidadão ao relacionar processos cognitivos com práticas psicossociais num tempo dinâmico, num espaço multidimensional, onde a ação ocorre e sob influência de vários quadrantes nem sempre percebida por todos ou...