2013
Authors
Silva, MF; Barbosa, RS; Castro, TS;
Publication
Nature-Inspired Mobile Robotics
Abstract
The presented work allowed the creation of a quadruped robot model (with flexible body, its legs and its hip and knee joints) in the virtual simulation program SimmechanicsTM. The final objective is to use this simulation model to optimize quadruped robot locomotion. The model developed accepts different gaits by direct introduction of the angular positions of the knee and hip joints. Feet-ground interaction was also modelled using a theoretic model described in the literature.
2013
Authors
Lopes, RL; Costa, E;
Publication
PROGRESS IN ARTIFICIAL INTELLIGENCE, EPIA 2013
Abstract
Evolutionary Algorithms (EA) are loosely inspired in the ideas of natural selection and genetics. Over the years some researchers have advocated the need of incorporating more ideas from biology into EAs, in particular with respect to the individuals' representation and the mapping from the genotype to the phenotype. One of the first successful proposals in that direction was the Artificial Regulatory Network (ARN) model. Soon after some variants of the ARN with increased capabilities were proposed, namely the Regulatory Network Computational Device (ReNCoDe). In this paper we further study ReNCoDe, testing the implications of some design choices of the underlying ARN model. A Genetic Programming community-approved symbolic regression benchmark (the harmonic number) is used to compare the performance of the different alternatives.
2013
Authors
Rosario, R; Araujo, A; Oliveira, B; Padrao, P; Lopes, O; Teixeira, V; Moreira, A; Barros, R; Pereira, B; Moreira, P;
Publication
PREVENTIVE MEDICINE
Abstract
Objective. To examine the effects of an intervention program held by teachers previously trained in nutrition, on the consumption of low nutrient, energy-dense (WED) foods, of children attending elementary schools. Method. 464 children (239 female, 6 to 12 years) from seven elementary Portuguese schools participated in this randomized trial. Three schools were allocated to the intervention, and four to the control group. The intervention program was based on the Health Promotion Model and social cognitive theory. Teachers previously trained by researchers in nutrition and healthy eating implemented the intervention in the classroom from November 2008 to March 2009. Sociodemographic, anthropometric, physical activity, and dietary assessments were performed before (2007/2008) and at the end of the intervention (2009). Dietary intake was gathered by a 24-hour dietary recall and two groups of LNED foods were defined, namely SSBs and solid LNED foods. Results. Children from intervention group reported a reduction whereas the control group reported an increase in solid LNED foods consumption. The odds of increasing solid LNED foods consumption was 0.48, 95%CI (0.24, 0.95) in the intervention schools. Conclusion. Our study provides further support for the success of intervention programs aimed at limiting the consumption of solid LNED foods in children.
2013
Authors
Pereira, AJC; Saraiva, JT;
Publication
ENERGY
Abstract
The Iberian power systems went through important changes at the legal, regulatory and organizational levels in the last 20 years. One of the most relevant ones was the increasing penetration of distributed generation, namely wind parks, together with the development of the common market involving Portugal and Spain. In Portugal, distributed generation is paid using feed in tariffs while in Spain it can choose between receiving a regulated feed in tariff or the market price plus a participation prize. The feed in scheme is now under discussion since it is argued that it represents an excessive cost that is internalized in the end user tariffs. However, this discussion is frequently conducted without complete knowledge of the real impact of wind power on the electricity market price, since it contributes to reduce the demand on the market thus inducing a price reduction. To clarify these issues we used a long term System Dynamics based model already reported in a previous publication to estimate the long term evolution of the market price. This model was applied to the Iberian generation system using different shares of wind power capacity to quantify the impact of wind power on the day-ahead electricity market price.
2013
Authors
Maia, C; Claro, J;
Publication
JOURNAL OF TECHNOLOGY TRANSFER
Abstract
The Proof of Concept phase in university technology transfer is considered to be critical for the success of both licensing and the creation of spin-off companies. In the United States, Proof of Concept Centers are emerging as successful structures to address the challenges of this phase. In this paper, we present a framework to assess the role for such a structure in a university ecosystem. The framework is built from previous references that we use to explicitly link the features of Proof of Concept Centers with the challenges of the Proof of Concept phase, and establish their specific contributions to the overall technology commercialization efforts of a university. We illustrate the application of this framework in a case study of the University of Coimbra, in Portugal, and develop a characterization that is representative of the role that a Proof of Concept Center can play in comparable university ecosystems that feature conventional technology commercialization structures, and struggle with the challenges of the Proof of Concept phase. Our study suggests that there is in fact a possible role for a Proof of Concept Center in the regional ecosystem of the University of Coimbra, with a potentially very relevant impact in the technology commercialization process, through networking outside academia and research environments, funding of Proof of Concept activities, and technology entrepreneurship education for the development of entrepreneurial skills for researchers.
2013
Authors
Costa, DG; Guedes, LA; Vasques, F; Portugal, P;
Publication
WSEAS Transactions on Communications
Abstract
Visual data monitoring in wireless sensor networks can significantly enrich a large set of surveillance and general purpose monitoring applications. However, transmission of image snapshots or video streams can rapidly deplete the energy resources of the deployed nodes, turning energy efficiency into a major optimization issue. During wireless transmissions, packets can be corrupted directly affecting the monitoring quality of the applications. One reasonable way to reduce quality loss is the transmission of redundant packets for higher error resilience, but additional packet transmissions may incur in undesirable energy consumption. Frequently, some monitoring quality loss may be tolerated since visual information retrieved from source nodes may have different relevance for the applications, according to the monitoring requirements and the current sensors' poses and fields of view. In such way, we propose that only high-relevant source nodes will transmit redundant packets, assuring error resilience only for the most relevant visual data for the monitoring application. Doing so, energy is saved over the network when fewer packets are transmitted in average, potentially enlarging the network lifetime with reduced impact to the overall monitoring quality. © 2013. WSEAS Transactions on Communications.
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