MyListBox

As redes sociais são estruturas compostas por indivíduos ou grupos que estão relacionados por gostos e preferências, culturas ou origens e valores ou ideais. Há alguns anos para cá, o conceito de rede social expandiu-se para a internet, e de um modo geral as redes sociais online têm como objectivo a criação de um perfil e a partilha do mesmo com amigos. Hoje em dia, há redes sociais que cumprem vários objectivos diferentes, seja apenas para partilhar o perfil de uma identidade (pessoa, grupo ou organização), seja para atingir um serviço específico, por exemplo partilhar o Curriculum Vitae. Embora haja muitos cépticos, as redes sociais ganham novos adeptos todos os dias, como tal, as redes sociais disponibilizam aplicações para dispositivos móveis para assim os seus utilizadores poderem obter a informação mais rápido, em qualquer altura, em qualquer lugar, no seu smartphone ou tablet. É imperativo que as aplicações para dispositivos móveis estão continuamente fornecer funcionalidades mais ricas, e mesmo apesar da actual aceitação das pessoas em relação aos dispositivos móveis, a tendência é para continuarem neste ritmo, ou até mesmo aumentar, pois os utilizadores estarão sempre a pedir mais, além disso, a concorrência entre os vendedores irá manter viva a evolução natural da tecnologia. Para construir uma empresa por trás de uma rede social exige um perfil empreendedor, e a vocação para o empreendedorismo não é baseada em Dna, cultura, origem ou religião, em breves palavras, não se nasce empreendedor. É algo que se desenvolve no tempo, e que se melhora com os erros cometidos, não só com os nossos mas como os erros de outros empreendedores. O espírito empreendedor é algo que cresce após a primeira ideia, e até mesmo antes, de forma inconsciente, através do desenvolvimento de competências específicas. A MyListBox é uma rede social que fornece um serviço específico, de criação de listas de presentes e partilha das mesmas com amigos e familiares, que disponibiliza aplicações para dispositivos móveis com iOS e Android, e futuramente aplicação para Windows Phone 7, que permitem os utilizadores acederem às suas listas, e às listas dos seus amigos a qualquer hora, em qualquer lugar mesmo não estando ligado à internet. No contexto do projecto MyListBox, o trabalho resultante desta tese teve como principais objectivos: - Apresentar as experiências no mundo do empreendedorismo - Resultados dos concursos de empreendedorismo - Estado da arte no universo das aplicações móveis - Avaliação dos mecanismos de segurança para aplicações móveis - Critérios da decisão na implementação dos métodos de consistência e replicação de dados.

Controlador Boundary-Scan

A crescente complexidade dos sistemas electrónicos associada a um desenvolvimento nas tecnologias de encapsulamento levou à miniaturização dos circuitos integrados, provocando dificuldades e limitações no diagnóstico e detecção de falhas, diminuindo drasticamente a aplicabilidade dos equipamentos ICT. Como forma de lidar com este problema surgiu a infra-estrutura Boundary Scan descrita na norma IEEE1149.1 “Test Access Port and Boundary-Scan Architecture”, aprovada em 1990. Sendo esta solução tecnicamente viável e interessante economicamente para o diagnóstico de defeitos, efectua também outras aplicações. O SVF surgiu do desejo de incutir e fazer com que os fornecedores independentes incluíssem a norma IEEE 1149.1, é desenvolvido num formato ASCII, com o objectivo de enviar sinais, aguardar pela sua resposta, segundo a máscara de dados baseada na norma IEEE1149.1. Actualmente a incorporação do Boundary Scan nos circuitos integrados está em grande expansão e consequentemente usufrui de uma forte implementação no mercado. Neste contexto o objectivo da dissertação é o desenvolvimento de um controlador boundary scan que implemente uma interface com o PC e possibilite o controlo e monitorização da aplicação de teste ao PCB. A arquitectura do controlador desenvolvido contém um módulo de Memória de entrada, um Controlador TAP e uma Memória de saída. A implementação do controlador foi feita através da utilização de uma FPGA, é um dispositivo lógico reconfiguráveis constituído por blocos lógicos e por uma rede de interligações, ambos configuráveis, que permitem ao utilizador implementar as mais variadas funções digitais. A utilização de uma FPGA tem a vantagem de permitir a versatilidade do controlador, facilidade na alteração do seu código e possibilidade de inserir mais controladores dentro da FPGA. Foi desenvolvido o protocolo de comunicação e sincronização entre os vários módulos, permitindo o controlo e monitorização dos estímulos enviados e recebidos ao PCB, executados automaticamente através do software do Controlador TAP e de acordo com a norma IEEE 1149.1. A solução proposta foi validada por simulação utilizando o simulador da Xilinx. Foram analisados todos os sinais que constituem o controlador e verificado o correcto funcionamento de todos os seus módulos. Esta solução executa todas as sequências pretendidas e necessárias (envio de estímulos) à realização dos testes ao PCB. Recebe e armazena os dados obtidos, enviando-os posteriormente para a memória de saída. A execução do trabalho permitiu concluir que os projectos de componentes electrónicos tenderão a ser descritos num nível de abstracção mais elevado, recorrendo cada vez mais ao uso de linguagens de hardware, no qual o VHDL é uma excelente ferramenta de programação. O controlador desenvolvido será uma ferramenta bastante útil e versátil para o teste de PCBs e outras funcionalidades disponibilizadas pelas infra-estruturas BS.

Device power management for real-time embedded systems

A large part of power dissipation in a system is generated by I/O devices. Increasingly these devices provide power saving mechanisms to inter alia enhance battery life. While I/O device scheduling has been studied in the past for realtime systems, the use of energy resources by these scheduling algorithms may be improved. These approaches are crafted considering a huge overhead of device transition. The technology enhancement has allowed the hardware vendors to reduce the device transition overhead and energy consumption. We propose an intra-task device scheduling algorithm for real time systems that allows to shut-down devices while ensuring the system schedulability. Our results show an energy gain of up to 90% in the best case when compared to the state-of-the-art.

Online intra-task device scheduling for hard real-time systems

A large part of power dissipation in a system is generated by I/O devices. Increasingly these devices provide power saving mechanisms, inter alia to enhance battery life. While I/O device scheduling has been studied in the past for realtime systems, the use of energy resources by these scheduling algorithms may be improved. These approaches are crafted considering a very large overhead of device transitions. Technology enhancements have allowed the hardware vendors to reduce the device transition overhead and energy consumption. We propose an intra-task device scheduling algorithm for real time systems that allows to shut-down devices while ensuring system schedulability. Our results show an energy gain of up to 90% when compared to the techniques proposed in the state-of-the-art.

A compositional scheduling framework for digital avionics systems

ARINC specification 653-2 describes the interface between application software and underlying middleware in a distributed real-time avionics system. The real-time workload in this system comprises of partitions, where each partition consists of one or more processes. Processes incur blocking and preemption overheads and can communicate with other processes in the system. In this work we develop compositional techniques for automated scheduling of such partitions and processes. At present, system designers manually schedule partitions based on interactions they have with the partition vendors. This approach is not only time consuming, but can also result in under utilization of resources. In contrast, the technique proposed in this paper is a principled approach for scheduling ARINC-653 partitions and therefore should facilitate system integration.

Determinação do teor de compostos aromáticos policíclicos de óleos minerais isolantes para transformadores

Mestrado em Engenharia Química - Ramo Optimização Energética na Indústria Química

Integrating the LMS in service oriented e-learning systems

Learning management systems are routinely used for presenting, solving and grading exercises with large classes. However, teachers are constrained to use questions with pre-defined answers, such as multiple-choice, to automatically correct the exercises of their students. Complex exercises cannot be evaluated automatically by the LMS and require the coordination of a set of heterogeneous systems. For instance, programming exercises require a specialized exercise resolution environment and automatic evaluation features, each provided by a different type of system. In this paper, the authors discuss an approach for the coordination of a network of eLearning systems supporting the resolution of exercises. The proposed approach is based on a pivot component embedded in the LMS and has two main roles: 1) provide an exercise resolution environment, and 2) coordinate communication between the LMS and other systems, exposing their functions as web services. The integration of the pivot component in the LMS relies on Learning Tools Interoperability (LTI). This paper presents an architecture to coordinate a network of eLearning systems and validate the proposed approach by creating such a network integrated with LMS from two different vendors.

Towards e-learning 2.0: case study of an e-learning environment

In these days the learning experience is no longer confined within the four walls of a classroom. Computers and primarily the internet have broadened this horizon by creating a way of delivering education that is known as e-learning. In the meantime, the internet, or more precisely, the Web is heading towards a new paradigm where the user is no longer just a consumer of information and becomes an active part in the communication. This two-way channel where the user takes the role of the producer of content triggered the appearance of new types of services such as Social Networks, Blogs and Wikis. To seize this second generation of communities and services, educational vendors are willing to develop e-learning systems focused on the new and emergent users needs. This paper describes the analysis and specification of an e-learning environment at our School (ESEIG) towards this new Web generation, called PEACE – Project for ESEIG Academic Environment. This new model relies on the integration of several services controlled by teachers and students such as social networks, repositories libraries, e-portfolios and e-conference sytems, intelligent tutors, recommendation systems, automatic evaluators, virtual classrooms and 3D avatars.

Using the learning tools interoperability framework for LMS integration in service oriented architectures

The LMS plays an indisputable role in the majority of the eLearning environments. This eLearning system type is often used for presenting, solving and grading simple exercises. However, exercises from complex domains, such as computer programming, require heterogeneous systems such as evaluation engines, learning objects repositories and exercise resolution environments. The coordination of networks of such disparate systems is rather complex. This work presents a standard approach for the coordination of a network of eLearning systems supporting the resolution of exercises. The proposed approach use a pivot component embedded in the LMS with two roles: provide an exercise resolution environment and coordinate the communication between the LMS and other systems exposing their functions as web services. The integration of the pivot component with the LMS relies on the Learning Tools Interoperability. The validation of this approach is made through the integration of the component with LMSs from two vendors.

Race-to-halt energy saving strategies

Energy consumption is one of the major issues for modern embedded systems. Early, power saving approaches mainly focused on dynamic power dissipation, while neglecting the static (leakage) energy consumption. However, technology improvements resulted in a case where static power dissipation increasingly dominates. Addressing this issue, hardware vendors have equipped modern processors with several sleep states. We propose a set of leakage-aware energy management approaches that reduce the energy consumption of embedded real-time systems while respecting the real-time constraints. Our algorithms are based on the race-to-halt strategy that tends to run the system at top speed with an aim to create long idle intervals, which are used to deploy a sleep state. The effectiveness of our algorithms is illustrated with an extensive set of simulations that show an improvement of up to 8% reduction in energy consumption over existing work at high utilization. The complexity of our algorithms is smaller when compared to state-of-the-art algorithms. We also eliminate assumptions made in the related work that restrict the practical application of the respective algorithms. Moreover, a novel study about the relation between the use of sleep intervals and the number of pre-emptions is also presented utilizing a large set of simulation results, where our algorithms reduce the experienced number of pre-emptions in all cases. Our results show that sleep states in general can save up to 30% of the overall number of pre-emptions when compared to the sleep-agnostic earliest-deadline-first algorithm.

Intra-Task Device Scheduling for Real-Time Embedded Systems

An ever increasing need for extra functionality in a single embedded system demands for extra Input/Output (I/O) devices, which are usually connected externally and are expensive in terms of energy consumption. To reduce their energy consumption, these devices are equipped with power saving mechanisms. While I/O device scheduling for real-time (RT) systems with such power saving features has been studied in the past, the use of energy resources by these scheduling algorithms may be improved. Technology enhancements in the semiconductor industry have allowed the hardware vendors to reduce the device transition and energy overheads. The decrease in overhead of sleep transitions has opened new opportunities to further reduce the device energy consumption. In this research effort, we propose an intra-task device scheduling algorithm for real-time systems that wakes up a device on demand and reduces its active time while ensuring system schedulability. This intra-task device scheduling algorithm is extended for devices with multiple sleep states to further minimise the overall device energy consumption of the system. The proposed algorithms have less complexity when compared to the conservative inter-task device scheduling algorithms. The system model used relaxes some of the assumptions commonly made in the state-of-the-art that restrict their practical relevance. Apart from the aforementioned advantages, the proposed algorithms are shown to demonstrate the substantial energy savings.

Towards Certifiable Multicore-based Platforms for Avionics

Work in Progress Session, 21st IEEE Real-Time and Embedded Techonology and Applications Symposium (RTAS 2015). 13 to 16, Apr, 2015, pp 27-28. Seattle, U.S.A..

Towards the Certification of Multicore Platforms in the Avionics Domain

Poster presented in Work in Progress Session, The 28th GI/ITG International Conference on Architecture of Computing Systems (ARCS 2015). 24 to 27, Mar, 2015. Porto, Portugal.

Towards the Certification of Multicore Platforms in the Avionics Domain

Presented at Work in Progress Session, The 28th GI/ITG International Conference on Architecture of Computing Systems (ARCS 2015). 24 to 27, Mar, 2015. Porto, Portugal.

A rule-based grapheme-to-phone converter for TTS systems in european portuguese

In this paper, a linguistically rule-based grapheme-to-phone (G2P) transcription algorithm is described for European Portuguese. A complete set of phonological and phonetic transcription rules regarding the European Portuguese standard variety is presented. This algorithm was implemented and tested by using online newspaper articles. The obtained experimental results gave rise to 98.80% of accuracy rate. Future developments in order to increase this value are foreseen. Our purpose with this work is to develop a module/ tool that can improve synthetic speech naturalness in European Portuguese. Other applications of this system can be expected like language teaching/learning. These results, together with our perspectives of future improvements, have proved the dramatic importance of linguistic knowledge on the development of Text-to-Speech systems (TTS).