Energy-efficient diversity combining for different access schemes in a multi-path dispersive channel

Dissertação para obtenção do Grau de Doutor em Engenharia Electrotécnica e Computadores

Adaptation as a part of system resilience. insights from fish producers organizations in Portugal

Complex problems of globalized society challenge its adaptive capacity. However, it is precisely the nature of these human induced problems that provide enough evidence to show that adaptability may not be on a resilient path. This thesis explores the ambiguity of the idea of adaptation (and its practice) and illustrates the ways in which adaptability contributes to resilience of social ecological systems. The thesis combines a case study and grounded theory approach and develops an analytical framework to study adaptability in resource users’ organizations: from what it depends on and what the key challenges are for resource management and system resilience. It does so for the specific case of fish producers’ organizations (POs) in Portugal. The findings suggest that while ecological and market context, including the type of crisis, may influence the character of fishers’ adaptation within POs (i.e. anticipatory, maladaptive and reactively adaptive), it does not determine it. Instead, it makes agency even more crucial (i.e. leadership, trust and agent’s perceptions in terms of their impact on fishers’ motivation to learn from each other). In sum, it was found that internal adaptation can improve POs’ contribution to fishery management and resilience, but it is not a panacea and may, in some cases, increase system vulnerability to change. Continuous maladaptation of some Portuguese POs points at a basic institutional problem (fish market regime), which clearly reduces fisheries resilience as it promotes overfishing. However, structural change may not be sufficient to address other barriers to Portuguese fishers’ (PO members) adaptability, such as history (collective memory) and associated problematic self-perceptions. The agency (people involved in structures and practices) also needs to change. What and how institutional change and agency change build on one another (e.g. comparison of fisheries governance in Portugal and other EU countries) is a topic to be explored in further research.

Determination of the most suitable oil pipeline route using GIS least cost path analysis

The Keystone XL has a big role for transforming Canadian oil to the USA. The function of the pipeline is decreasing the dependency of the American oil industry on other countries and it will help to limit external debt. The proposed pipeline seeks the most suitable route which cannot damage agricultural and natural water recourses such as the Ogallala Aquifer. Using the Geographic Information System (GIS) techniques, the suggested path in this study got extremely high correct results that will help in the future to use the least cost analysis for similar studies. The route analysis contains different weighted overlay surfaces, each, was influenced by various criteria (slope, geology, population and land use). The resulted least cost path routes for each weighted overlay surface were compared with the original proposed pipeline and each displayed surface was more effective than the proposed Keystone XL pipeline.

The Vase’s Representation (Cantharus, Crater) on the Roman Mosaic in Portugal: A Significant Formal and Iconographic Path from Classic Antiquity to Late Antiquity

11TH INTERNATIONAL COLLOQUIUM ON ANCIENT MOSAICS OCTOBER 16TH  20TH, 2009, BURSA TURKEY Mosaics of Turkey and Parallel Developments in the Rest of the Ancient and Medieval World: Questions of Iconography, Style and Technique from the Beginnings of Mosaic until the Late Byzantine Era

Strategic account management: the path to gain customer loyalty

The account management field works closely with the sales team, serving as the customer’s primary point of contact. This project’s purpose was to understand if shifting the account management from brand centric to customer centric, would be the best fit for a Portuguese Pharmaceutical company. This customer centric approach - Strategic Account Management (SAM) - was studied, understanding the implicated trade-offs to the company. The workforce was probed about the project and their comments were analyzed. The conclusion points to an implementation of SAM and proposes the adaptations to follow in order to smooth the change.

A violência doméstica no seio da relação conjugal e a sua relação com o estatuto da mulher na sociedade

Domestic violence is one of the most serious problems that contemporary society faces. Domestic violence that specifically occurs between spouses is a particular case of domestic violence that has caused a high number of victims - mostly women - putting thus an enormous challenge to states with regard to combating this problem. In this thesis we intend to proceed with the study of this phenomenon in the Angolan context. The objective of this study is trying to understand how such violence is manifested in Angola, what factors may be at it’s source and what effects can be observed on the victims, their families and in society itself. Being the Angolan people strongly linked to traditions and customs, it seemed interesting to also address the issue of domestic violence under customary law. In addition to the problem of the study itself, we proceed to exposure and analysis of how the state and civil society have intervened in this matter. At the end of this study, we conclude that despite the fact that the issue of domestic violence has received more attention in recent years from the public entities and society in general, there is still a long way to go. This path involves not only more actions of the state but also a change of mentality, which can enable the break with social stereotypes in adopting a different behavior over the issue under review and internalizing that human dignity is the basic principle of any state that proclaims democratic rights.

A public transport bus assignment problem: parallel metaheuristics assessment

Combinatorial Optimization Problems occur in a wide variety of contexts and generally are NP-hard problems. At a corporate level solving this problems is of great importance since they contribute to the optimization of operational costs. In this thesis we propose to solve the Public Transport Bus Assignment problem considering an heterogeneous fleet and line exchanges, a variant of the Multi-Depot Vehicle Scheduling Problem in which additional constraints are enforced to model a real life scenario. The number of constraints involved and the large number of variables makes impracticable solving to optimality using complete search techniques. Therefore, we explore metaheuristics, that sacrifice optimality to produce solutions in feasible time. More concretely, we focus on the development of algorithms based on a sophisticated metaheuristic, Ant-Colony Optimization (ACO), which is based on a stochastic learning mechanism. For complex problems with a considerable number of constraints, sophisticated metaheuristics may fail to produce quality solutions in a reasonable amount of time. Thus, we developed parallel shared-memory (SM) synchronous ACO algorithms, however, synchronism originates the straggler problem. Therefore, we proposed three SM asynchronous algorithms that break the original algorithm semantics and differ on the degree of concurrency allowed while manipulating the learned information. Our results show that our sequential ACO algorithms produced better solutions than a Restarts metaheuristic, the ACO algorithms were able to learn and better solutions were achieved by increasing the amount of cooperation (number of search agents). Regarding parallel algorithms, our asynchronous ACO algorithms outperformed synchronous ones in terms of speedup and solution quality, achieving speedups of 17.6x. The cooperation scheme imposed by asynchronism also achieved a better learning rate than the original one.

Social venture move

This study has the purpose of presenting the path of a social microcredit start-up in Mozambique. Its members had just gotten out of college and decided to put in practice what they had learnt. Even though the whole foundation of the project was developed in Mozambique, the team has extended its experience to other countries: São Tomé and Timor. However, the focus of this study will be solely in the Ilha de Mozambique’s project and the difficulties that it is facing right now, in order to try to find answers that would allow the project entrepreneurs to overcome what is keeping them from having a more successful return rate. The main issue of the project and the worse and unexpected default rate is within the fishing sector. This is peculiar, since the mission is in an island where there are plenty of fish and shellfish. By addressing this problem, and presenting the whole structure of the venture, it is its goal to understand better ways to deal with the difficulties. Its format will be as a case study and it will present as well the macroeconomics of Mozambique to justify the choice of the place, align with the team itself, and why it is possible to have a successful project with as many contacts and sponsors as this one does.