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Percorrer ESTG - Capítulos de livros por Objetivos de Desenvolvimento Sustentável (ODS) "07:Energias Renováveis e Acessíveis"
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- Analysis of Power Quality Disturbances in Industry in the Centre Region of PortugalPublication . Moreira, Licinio; Leitão, Sérgio; Vale, Zita; Galvão, João; Franco Marques, Pedro JoséPower quality issues have taken a more prominent role in power systems over the last years. These issues are of major concern for energy customers, primarily for customers with a widespread use of electronic devices in their manufacturing processes. Even though the quality of service is increasing, customers are becoming more demanding of the energy provider. This research aims to provide some industrial managers the technical support in deciding of investments in the mitigation of power quality disturbances, such as the use of less sensitive devices or the use of interface devices (UPS, DVR...) In order to recommend an appropriate solution, the problem is characterized. The technical and economic influences of the PQ disturbances in the manufacturing processes are assessed resorting to power quality audits in the customer facilities. This research covered a significant number of facilities in several industrial activities.
- Database Marketing Process Supported by OntologiesPublication . Mota Pinto, Filipe; Marques, Alzira; Santos, Manuel FilipeThe dramatic explosion of data and the growing number of different data sources are exposing researchers to a new challenge - how to acquire, maintain, and share knowledge from large databases in the context of rapidly applied and evolving research. This paper describes research on an ontological approach for leveraging the semantic content of ontologies to improve knowledge discovery in databases. We analyze how ontologies and knowledge discovery process may interoperate and present our efforts to bridge the two fields, knowledge discovery in databases and ontology learning for successful database usage projects.
- Distribution of the Number of Losses in Busy-Periods of Mx/G/1/n SystemsPublication . Ferreira, Fátima; Pacheco, António; Ribeiro, HelenaThis chapter addresses MX=G=1=n queues, i.e., single server batch Markovian arrival queues with finite customer waiting space of size n. Taking profit of the Markov regenerative structure of these systems, we develop an efficient recursive procedure to compute the probability mass function of the number of losses in busy-periods starting with an arbitrary number of customers in the system. The derived computational procedure is easy to implement and leads to a fast numerical computation of the loss probabilities. To illustrate the effectiveness of the procedure, loss probabilities are computed for a wide variety of queues, with different capacities, batch size distributions, and arrival and service parameters.
- Extensions of Dorfman’s TheoryPublication . Santos, Rui; Pestana, Dinis; Martins, João PauloEconomic impact of composite sampling is investigated in the realistic framework of tests with positive probability of false positive and of false negative results. Sensitivity and specificity when pooling samples are also discussed, using rarefaction as a framework.
- A Face Attention Technique for a Robot Able to Interpret Facial ExpressionsPublication . Simplício, Carlos; Prado, José; Dias, JorgeAutomatic facial expressions recognition using vision is an important subject towards human-robot interaction. Here is proposed a human face focus of attention technique and a facial expressions classifier (a Dynamic Bayesian Network) to incorporate in an autonomous mobile agent whose hardware is composed by a robotic platform and a robotic head. The focus of attention technique is based on the symmetry presented by human faces. By using the output of this module the autonomous agent keeps always targeting the human face frontally. In order to accomplish this, the robot platform performs an arc centered at the human; thus the robotic head, when necessary, moves synchronized. In the proposed probabilistic classifier the information is propagated, from the previous instant, in a lower level of the network, to the current instant. Moreover, to recognize facial expressions are used not only positive evidences but also negative.
- Hybrid model for the energy efficiency of building servicesPublication . Galvão, João; Leitão, Sérgio; Malheiro, Salvador; Gaio, TiagoEnergy is used in multiple activities and represents a fundamental good for the planet and well being of populations. From this stems a steady increase in energy consumption worldwide through the last decade, and it is well known that growing population usually accelerates its consumption.The primary energy consumed on the planet currently has origin in fossil fuels, once responsible for GHG (greenhouse gas) emission source, contributing to the global warming and climate change.In this context to meeting the commitments of the Kyoto Protocol and European standards, it is urgent that there is an increasing integration of all forms of renewable energy, in industrial and economic areas.Consequently, there should be an adaptation to environmental factors and sustainability of the processes of energy production and consumptions, associated with measures that encourage energy efficiency and educate people to the good energy practices, reducing waste also increasing the quality of life of humanity. © 2012 by Nova Science Publishers, Inc. All rights reserved.
- Indicator-Based Evolutionary Level Set Approximation: Mixed Mutation Strategy and Extended AnalysisPublication . Liu, Lai-Yee; Basto-Fernandes, Vitor; Yevseyeva, Iryna; Kok, Joost; Emmerich, MichaelThe aim of evolutionary level set approximation is to find a finite representation of a level set of a given black box function. The problem of level set approximation plays a vital role in solving problems, for instance in fault detection in water distribution systems, engineering design, parameter identification in gene regulatory networks, and in drug discovery. The goal is to create algorithms that quickly converge to feasible solutions and then achieve a good coverage of the level set. The population based search scheme of evolutionary algorithms makes this type of algorithms well suited to target such problems. In this paper, the focus is on continuous black box functions and we propose a challenging benchmark for this problem domain and propose dual mutation strategies, that balance between global exploration and local refinement. Moreover, the article investigates the role of different indicators for measuring the coverage of the level set approximation. The results are promising and show that even for difficult problems in moderate dimension the proposed evolutionary level set approximation algorithm (ELSA) can serve as a versatile and robust meta-heuristic.
- Low Cost Smart Homes for EldersPublication . Ferreira, Gabriel; Penicheiro, Paulo; Bernardo, Ruben; Mendes, Luís; Barroso, João; Pereira, AntónioThe increase in life expectancy and the consequent aging of the general population pose, nowadays, major challenges to modern societies. Most elderly people have the usual problems related to old age, like health chronic problems and sensory and cognitive impairments. Besides that, in today’s modern societies, where families have less and less time to look after for their old relatives, the isolation of the elderly is a real concern and a very current problem, which is enhanced if the elders live alone. To solve or, at least, mitigate that problem, it was developed a smart home for elders that is presented and described in this paper. The developed assistive home system, which is based on available technology, can ensure the quality of life, safety and well-being of all older adults that want or desire to live in the comfort of their home, near to their friends and in their neighborhood, instead of living in elder care centers.
- A Mechanism for Verifying the Integrity and Immutability of Tuberculosis Data Using IOTA Distributed Ledger TechnologyPublication . Lima, Vinícius; Bernardi, Filipe; Rijo, Rui; Ueyama, Jó; Alves, DomingosBackground: Intensified research and innovation and rapid uptake of new tools, interventions, and strategies are crucial to fight Tuberculosis, the world's deadliest infectious disease. The sharing of health data remains a significant challenge. Data consumers must be able to verify the consistency and integrity of data. Solutions based on distributed ledger technologies may be adequate, where each member in a network holds a unique credential and stores an identical copy of the ledger and contributes to the collective process of validating and certifying digital transactions. Objectives: This work proposes a mechanism and presents a use case in Digital Health to allow the verification of integrity and immutability of TB electronic health records. Methods: IOTA was selected as a supporting tool due to its data immutability, traceability and tamper-proof characteristics. Results: A mechanism to verify the integrity of data through hash functions and the IOTA network is proposed. Then, a set of TB related information systems was integrated with the network. Conclusion: IOTA technology offers performance and flexibility to enable a reliable environment for electronic health records.
- Natural ventilation potential on thermal comfort of a light-steel-framing residential buildingPublication . Craveiro, A.; Lopes, A.; Santos, P.; Silva, L. daNowadays, given the increasing comfort requirements that are imposed on buildings and the overall energy concerns, it is not reasonable dissociate ventilation from the thermal comfort. In fact, ventilation, as passive strategy, when properly studied and implemented on a building, may contribute to the thermal performance increase, and also, to minimize the energy expenditure required to achieve comfortable conditions with consequent improvement of building energy efficiency. In order to predict natural ventilation potential on the comfort increase, as passive strategy in a purely climatic analysis, a simplistic analysis on two different European scenarios is presented using the Autodesk Ecotect weather tool. In addition, some outcomes of numerical simulations, using Design Builder software, aims to highlight the importance of natural ventilation on the thermal behaviour of a light-steel-framing residential building: CoolHaven building