2012
Authors
Couceiro, MS; Tenreiro Machado, JAT; Rocha, RP; Ferreira, NMF;
Publication
ROBOTICS AND AUTONOMOUS SYSTEMS
Abstract
The Darwinian Particle Swarm Optimization (DPSO) is an evolutionary algorithm that extends the Particle Swarm Optimization using natural selection to enhance the ability to escape from sub-optimal solutions. An extension of the DPSO to multi-robot applications has been recently proposed and denoted as Robotic Darwinian PSO (RDPSO), benefiting from the dynamical partitioning of the whole population of robots, hence decreasing the amount of required information exchange among robots. This paper further extends the previously proposed algorithm adapting the behavior of robots based on a set of context-based evaluation metrics. Those metrics are then used as inputs of a fuzzy system so as to systematically adjust the RDPSO parameters (i.e., outputs of the fuzzy system), thus improving its convergence rate, susceptibility to obstacles and communication constraints. The adapted RDPSO is evaluated in groups of physical robots, being further explored using larger populations of simulated mobile robots within a larger scenario.
2012
Authors
Ferreira, C; Grinde, C; Morais, R; Valente, A; Neves, C; Reis, M;
Publication
26TH EUROPEAN CONFERENCE ON SOLID-STATE TRANSDUCERS, EUROSENSOR 2012
Abstract
This paper presents a piezoresistive pressure sensor with a measurement span of 1MPa and capable to withstand peak pressures around 10MPa. The sensor design, based on a square membrane, was optimized for enhanced sensitivity, high linearity and low sensitivity variations between fabricated samples. Being the asymmetry of the mechanical stress peaks, the ratio between the membrane area and its thickness, and the tolerances of the bulk micromachining process considered for the optimal positioning of the piezoresistive sensing elements. Practical results show a mean sensitivity of 30.9mV/V/MPa with a standard deviation of 0.65mV/V/MPa and a linearity error of 0.15% of the scale span. (C) 2012 Elsevier Ltd....Selection and/or peer-review under responsibility of the Symposium Cracoviense Sp. z.o.o.
2012
Authors
Oliveira, JN;
Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Abstract
There is a need for a language able to reconcile the recent upsurge of interest in quantitative methods in the software sciences with logic and set theory that have been used for so many years in capturing the qualitative aspects of the same body of knowledge. Such a lingua franca should be typed, polymorphic, diagrammatic, calculational and easy to blend with traditional notation. This paper puts forward typed linear algebra (LA) as a candidate notation for such a role. Typed LA emerges from regarding matrices as morphisms of suitable categories whereby traditional linear algebra is equipped with a type system. In this paper we show typed LA at work in describing weighted (probabilistic) automata. Some attention is paid to the interface between the index-free language of matrix combinators and the corresponding index-wise notation, so as to blend with traditional set theoretic notation. © 2012 Springer-Verlag.
2012
Authors
Carvalho, JP; Coelho, L; Pontes, MJ; Barbero, AP; Martinez, MA; Ribeiro, RM; Weyl, J; Baptista, JM; Giraldi, MTR; Dias, I; Santos, JL; Frazao, O;
Publication
IEEE SENSORS JOURNAL
Abstract
It is reported a long-period grating (LPG) dynamic interrogation technique based on the modulation of fiber Bragg gratings located in the readout unit of the system. It permits to attenuate the effect of the 1/f noise of the electronics in the resolution of the LPG-based sensing head. The concept is tested to detect variations of the external refractive index and a resolution of 2.0 x 10(-4) NIR was achieved without system optimization. Additionally, the effect in the sensor resolution when introducing Erbium and Raman optical amplification is experimentally investigated.
2012
Authors
Goncalves, RC; Sobral, JL;
Publication
MISS'12 - Proceedings of the 2012 Workshop on Modularity in Systems Software
Abstract
This paper presents an aspect-oriented library to support parallelization of Java applications for distributed memory environments, using a message-passing approach. The library was implemented using AspectJ language, and aims to provide a set of mechanisms to make easier to parallelize applications, as well as to solve well known problems of parallelization, such as lack of modularity and reusability. We compare the advantages of this method over the traditional approach, and we discuss differences to recent approaches that address the same problem. Results show benefits over other approaches, and, in most of cases, a competitive performance. © 2012 ACM.
2012
Authors
Pinho, T; Silva, A; Rodrigues, C; Amaral, A;
Publication
PROCEEDINGS OF THE 7TH EUROPEAN CONFERENCE ON INNOVATION AND ENTREPRENEURSHIP, VOLS 1 AND 2
Abstract
This paper aims to point up the critical topics that need to be addressed towards a fully implementation of lean management as well as the adoption of learning mechanisms and information and communication systems in order to attain organisational differentiation through performance enhancement and integration of management practices that favour business sustainability. Firstly, we will try to explain the complexity of a construction project and how lean principles can be adapted to the construction industry, as well as some practical examples of the adoption of new technologies. Then, it will be explained how knowledge management and learning mechanisms can be critical in attaining a competitive advantage in this sector. Finally, a conceptual model will be presented based on the literature studies and the main results obtained from the focus group conducted with project managers from the construction area.
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