2012
Authors
El Hosiny Ali, HE; Jimenez, R; Ricote, J; Perez de la Cruz, JP; Fernandes, JRA; Calzada, ML;
Publication
THIN SOLID FILMS
Abstract
It has been reported that ferroelectric and piezoelectric properties of Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMNT) thin films, with compositions close to the morphotropic phase boundary (MPB), show lower values than those reported for bulk ceramics with the same composition, which has been attributed to a reduction of the remnant polarization caused by the small size of the grains in the films. An alternative has been proposed to take full advantage of the excellent piezoelectric properties of polycrystalline PMNT in thin film form: a multilayer configuration that uses ferroelectric layers with large remnant polarization, in this case PbTiO3, to generate an internal electric bias within the PMNT layers and, thus, anchor an induced polarization on them, resulting in a consequent large piezoelectric behavior. The detailed study of the properties of these multilayer composite films reveals the complex correlations that arise in these heterostructures, which are key for the design of optimized piezoelectric films based on MPB PMNT.
2012
Authors
Schaller, J; Valente, JMS;
Publication
COMPUTERS & OPERATIONS RESEARCH
Abstract
This paper considers a problem in which there is a set of jobs to be sequenced on a single machine. Each job has a weight and the objective is to sequence the jobs to minimize total weighted squared tardiness. A branch-and-bound algorithm is developed for optimally solving the problem. Several dominance conditions are presented for possible inclusion in the branch-and-bound algorithm. The dominance conditions are included in the branch-and-bound algorithm, which is tested on randomly generated problems of various numbers of jobs, due date tightness and due date ranges. The results show that the dominance conditions dramatically improve the efficiency of the branch-and-bound algorithm.
2012
Authors
Holzapfel, A; Davies, MEP; Zapata, JR; Oliveira, JL; Gouyon, F;
Publication
IEEE TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING
Abstract
In this paper, we propose a method that can identify challenging music samples for beat tracking without ground truth. Our method, motivated by the machine learning method "selective sampling," is based on the measurement of mutual agreement between beat sequences. In calculating this mutual agreement we show the critical influence of different evaluation measures. Using our approach we demonstrate how to compile a new evaluation dataset comprised of difficult excerpts for beat tracking and examine this difficulty in the context of perceptual and musical properties. Based on tag analysis we indicate the musical properties where future advances in beat tracking research would be most profitable and where beat tracking is too difficult to be attempted. Finally, we demonstrate how our mutual agreement method can be used to improve beat tracking accuracy on large music collections.
2012
Authors
Araujo, R; Igreja, A; de Castro, R; Araujo, RE;
Publication
2012 IEEE INTELLIGENT VEHICLES SYMPOSIUM (IV)
Abstract
In spite of several technical advances made in recent years by the automotive industry, the driver's behaviour still influences significantly the overall fuel consumption. With the rise of smartphones adoption, there are also new opportunities to increase the awareness to this issue. The main aim of this paper is to present a new smartphone application that will help drivers reduce the fuel consumption of their vehicles. This is accomplished by using the smartphone's sensors and the vehicle state to detect the driving pattern and suggest new behaviours in real time that will lead to a more efficient driving experience. The preliminary results show the potential for significant energy savings and their relevance for changing the drivers' behaviour.
2012
Authors
M.B., J; M., L; Coelho, D; M., H; C.S., J;
Publication
Ultra Wideband - Current Status and Future Trends
Abstract
2012
Authors
Marco Mendes, JM; Leitao, P; Colombo, AW; Restivo, F;
Publication
INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH
Abstract
The use of service-orientation principles in manufacturing systems is a promising solution to achieve modularity, flexibility, re-configurability and interoperability. Crucial issues in these service-oriented systems are the description and co-ordination of the execution of the services offered by the distributed entities. This paper introduces an integrated approach for the design, analysis, validation, simulation and process execution of service-oriented manufacturing systems, using the High-level Petri net formalism as the formal language to describe the system behaviour. The use of the proposed approach contributes to achieving an easier and faster development of these solutions and provides the basis to support modularity and re-configurability.
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