Three transducers for one photodetector: essays for optical communications

Dissertation presented to obtain the PhD degree in Electrical and Computer Engineering - Electronics

Self-initiation expatriation: A focus on Italian and Portuguese students

The purpose of this work project is to analyze the phenomenon of self-initiated expatriation (SIE) through its link to the Protean Career and Career Capital theories, focusing in particular on Italian and Portuguese students attending a Master in the business area. The main research questions are to understand the reasons driving the intention to expatriate, after the conclusion of the academic path, using three main categories (Adventure Motivation, Work Characteristic Motivation and instrumental Motivation) and the intention to repatriate. A sample of Italian and Portuguese students was obtained. Italians show a higher intention to expatriate relative to Portuguese; nevertheless, no other significant differences were found among the two populations, because of the similar cultural background and economic situation. Additionally, several heterogeneities were observed considering other clusters defined by Gender, Teaching Language of the Master and Past International Experiences, across the two nationalities. Furthermore, possible future researches and practical implications were discussed.

Democratic dialogue and collective learning in the context of self-managed teams

This paper provides a longitudinal, empirical view of the multifaceted and reciprocal processes of organizational learning in a context of self-managed teams. Organizational learning is seen as a social construction between people and actions in a work setting. The notion of learning as situated (Brown & Duguid 1989, Lave& Wenger 1991, Gherardi & al. 1998, Easterby-Smith & Araujo 1999, Abma 2003) opens up the possibility for placing the focus of research on learning in the community rather than in individual learning processes. Further, in studying processes in their social context, we cannot avoid taking power relations into consideration (Contu & Willmott 2003). The study is based on an action research with a methodology close to the ‘democratic dialogue’ presented by Gustavsen (2001). This gives a ground for research into how the learning discourse developed in the case study organization over a period of 5 years, during which time the company abandoned a middle management level of hierarchy and the teams had to figure out how to work as self-managed units. This paper discusses the (re)construction of power relations and its role in organizational learning. Power relations are discussed both in vertical and horizontal work relations. A special emphasis is placed on the dialectic between managerial aims and the space for reflection on the side of employees. I argue that learning is crucial in the search for the limits for empowerment and that these limits are negotiated both in actions and speech. This study unfolds a purpose-oriented learning process, constructing an open dialogue, and describes a favourable context for creative, knowledge building communities.

Working in IT projects – Options and Limits of Work Design

Flexible forms of work like project work are gaining importance in industry and services. Looking at the research on project work, the vast majority of present literature is on project management, but increasingly, problems concerning the quality of work and the efficiency of project teams become visible. The question now is how project work can be structured in order to simultaneously provide efficient and flexible work and healthy working conditions ensuring the development of human resources for a long time. Selected results of publicly funded research into project work will be presented based on case studies in 7 software development /IT consulting project teams (N=34). A set of different methods was applied: interviews with management/project managers, group interviews on work constraints, a monthly diary about well-being and critical incidences in the course of the project, and a final evaluation questionnaire on project outcomes focusing on economic and health aspects. Findings reveal that different types of projects exist with varying degree of team members’ autonomy and influence on work structuring. An effect of self-regulation on mental strain could not be found. The results emphasize, that contradicting requirements and insufficient organizational resources with respect to the work requirements lead to an increased work intensity or work obstruction. These contradicting requirements are identified as main drivers for generating stress. Finally, employees with high values on stress for more than 2 months have significantly higher exhaustion rates than those with only one month peaks. Structuring project work and taking into account the dynamics of project work, there is a need for an active role of the project team in contract negotiation or the detailed definition of work – this is not only a question of individual autonomy but of negotiation the range of option for work structuring. Therefore, along with the sequential definition of the (software) product, the working conditions need to be re-defined.

Self-organization and complexity theory to support evolvable production systems

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

Digital-domain self-calibration technique for video-rate pipeline A/D converters using Gaussian white noise

Electronics Letters Vol.38, nº 19

Visualization of clusters in geo-referenced data using three-dimensional self-organizing maps

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação

Aprendizagem autónoma (self-directed learning): relatório de um atelier pedagógico

Educação Médica. 1994, 5(3):178-181.

CARTO-SOM - Cartogram creation using self-organizing maps

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica

Exploratory geospatial data analysis using self-organizing maps

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica

New simple digital self-calibration technique for pipeline ADCs using the internal thermal noise

IEEE International Symposium on Circuits and Systems, pp. 232 – 235, Seattle, EUA

Efficient digital self-calibration of video-rate pipeline ADCs using white gaussian noise

Proceedings of IEEE, ISCAS 2003, Vol.I, pp. 877-880

Utilização do algoritmo Self-Organizing Map na caracterização de organizações públicas portuguesas.

Dissertação apresentada como requisito parcial para a obtenção do grau de mestre em Estatística e Gestão de Informação.

Natural and amyloid self-assembly of S100 proteins: structural basis of functional diversity

The S100 proteins are 10-12 kDa EF-hand proteins that act as central regulators in a multitude of cellular processes including cell survival, proliferation, differentiation and motility. Consequently, many S100 proteins are implicated and display marked changes in their expression levels in many types of cancer, neurodegenerative disorders, inflammatory and autoimmune diseases. The structure and function of S100 proteins are modulated by metal ions via Ca2+ binding through EF-hand motifs and binding of Zn2+ and Cu2+ at additional sites, usually at the homodimer interfaces. Ca2+ binding modulates S100 conformational opening and thus promotes and affects the interaction with p53, the receptor for advanced glycation endproducts and Toll-like receptor 4, among many others. Structural plasticity also occurs at the quaternary level, where several S100 proteins self-assemble into multiple oligomeric states, many being functionally relevant. Recently, we have found that the S100A8/A9 proteins are involved in amyloidogenic processes in corpora amylacea of prostate cancer patients, and undergo metal-mediated amyloid oligomerization and fibrillation in vitro. Here we review the unique chemical and structural properties of S100 proteins that underlie the conformational changes resulting in their oligomerization upon metal ion binding and ultimately in functional control. The possibility that S100 proteins have intrinsic amyloid-forming capacity is also addressed, as well as the hypothesis that amyloid self-assemblies may, under particular physiological conditions, affect the S100 functions within the cellular milieu.

Caracterização da situação orçamental no poder local em indicadores orçamentais e self-organizing map.

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação.