IP/optical integration in access network infrastructures: key issues on resource provisioning

This thesis contributes to the advancement of Fiber-Wireless (FiWi) access technologies, through the development of algorithms for resource allocation and energy efficient routing. FiWi access networks use both optical and wireless/cellular technologies to provide high bandwidth and ubiquity, required by users and current high demanding services. FiWi access technologies are divided in two parts. In one of the parts, fiber is brought from the central office to near the users, while in the other part wireless routers or base stations take over and provide Internet access to users. Many technologies can be used at both the optical and wireless parts, which lead to different integration and optimization problems to be solved. In this thesis, the focus will be on FiWi access networks that use a passive optical network at the optical section and a wireless mesh network at the wireless section. In such networks, two important aspects that influence network performance are: allocation of resources and traffic routing throughout the mesh section. In this thesis, both problems are addressed. A fair bandwidth allocation algorithm is developed, which provides fairness in terms of bandwidth and in terms of experienced delays among all users. As for routing, an energy efficient routing algorithm is proposed that optimizes sleeping and productive periods throughout the wireless and optical sections. To develop the stated algorithms, game theory and networks formation theory were used. These are powerful mathematical tools that can be used to solve problems involving agents with conflicting interests. Since, usually, these tools are not common knowledge, a brief survey on game theory and network formation theory is provided to explain the concepts that are used throughout the thesis. As such, this thesis also serves as a showcase on the use of game theory and network formation theory to develop new algorithms.

Ecotourism snorkelling routes at Marinha Beach (Algarve)

Coastal ecotourism is one of the fastest growing leisure industries in the world and snorkelling is emerging as an important beach-based activity. Snorkelling has the potential to enhance biodiversity conservation when developed within environmental education framework. The aim of this study was to implement and evaluate snorkelling routes, in the Algarve (South Portugal), as a sustainable ecotourism offer. To achieve these objectives, three snorkelling routes were established at the pristine Marinha beach. After the diving experience, a face-to-face questionnaire survey was conducted to collect information about individuals' opinions regarding the underwater routes, their social demographic characteristics, ecological appreciation, opinions about beach facilities and trip expenditures. The survey was undertaken during the summer months of 2008 and 2009, and 202 people were interviewed. Data was analysed using univariate and multivariate statistic methods. Most respondents perceived the existence of routes to be good for the preservation of the local biodiversity and reported this experience as "good" or "excellent". The only difference in perceptions was observed by visitor snorkelling in groups of more than two people. Interviewers consider that emergency support and sanitary facilities are the most important beach support infrastructures. Overall, these routes seem to be an effective tool for developing ecological awareness in tourists, as they enhance the preservation and the understanding of the marine coastal environment.

A ilha de Moçambique durante a Idade Moderna

Dissertação de Mestrado, História da Arte Portuguesa, Faculdade de Ciências Humanans e Sociais, Universidade do Algarve, 2007

Determinação da qualidade do fruto em citrinos de diferentes modos de produção

Dissertação mest., Agricultura Sustentável, Universidade do Algarve, 2007

Water use and conservation at the environmental protection area of Brilhante, Santa Catarina - Brazil

Dissertação mest., Gestão da Água e da Costa, Universidade do Algarve, 2008