2017
Autores
Cardoso, DO; Franca, FMG; Gama, J;
Publicação
NEW GENERATION COMPUTING
Abstract
Clustering is a powerful and versatile tool for knowledge discovery, able to provide a valuable information for data analysis in various domains. To perform this task based on streaming data is quite challenging: outdated knowledge needs to be disposed while the current knowledge is obtained from fresh data; since data are continuously flowing, strict efficiency constraints have to be met. This paper presents WCDS, an approach to this problem based on the WiSARD artificial neural network model. This model already had useful characteristics as inherent incremental learning capability and patent functioning speed. These were combined with novel features as an adaptive countermeasure to cluster imbalance, a mechanism to discard expired data, and offline clustering based on a pairwise similarity measure for WiSARD discriminators. In an insightful experimental evaluation, the proposed system had an excellent performance according to multiple quality standards. This supports its applicability for the analysis of data streams.
2017
Autores
Almeida, JB; Barbosa, M; Barthe, G; Blot, A; Grégoire, B; Laporte, V; Oliveira, T; Pacheco, H; Schmidt, B; Strub, PY;
Publicação
CCS'17: PROCEEDINGS OF THE 2017 ACM SIGSAC CONFERENCE ON COMPUTER AND COMMUNICATIONS SECURITY
Abstract
Jasmin is a framework for developing high-speed and high-assurance cryptographic software. The framework is structured around the Jasmin programming language and its compiler. The language is designed for enhancing portability of programs and for simplifying verification tasks. The compiler is designed to achieve predictability and efficiency of the output code (currently limited to x64 platforms), and is formally verified in the Coq proof assistant. Using the SUPER COP framework, we evaluate the Jasmin compiler on representative cryptographic routines and conclude that the code generated by the compiler is as efficient as fast, hand-crafted, implementations. Moreover, the framework includes highly automated tools for proving memory safety and constant-time security (for protecting against cache-based timing attacks). We also demonstrate the effectiveness of the verification tools on a large set of cryptographic routines.
2017
Autores
Silva, S; Queirós, S; Moreira, AH; Oliveira, E; Rodrigues, NF; Vilaça, JL;
Publicação
2017 IEEE 5TH INTERNATIONAL CONFERENCE ON SERIOUS GAMES AND APPLICATIONS FOR HEALTH (SEGAH)
Abstract
Bad posture while working or playing videogames can affect our life quality and impose negative economic consequences over time. There's raising concern in companies regarding worker's wellness, many adopting preventive measures. Specialized training in posture is important to prevent occupational activities risks and to foster health promotion. In this paper, we present a study of different classifiers to detect good and bad body postures in workplaces. A set classifiers, namely artificial neural networks, support vector machine, decision trees, discriminant analysis, logistic regression, treebagger and naïve Bayes, were tested in three-dimensional acquisitions of 100 people for automatic determination of the type of body posture. The best classifier was the treebagger with a rating of True Positive and True Negative of 93.3% and 96.2%, respectively.
2017
Autores
de Oliveira, SF; Soares, AL;
Publicação
COLLABORATION IN A DATA-RICH WORLD
Abstract
Due to growing concerns with sustainability issues and the emergence of the Circular Economy (CE) paradigm, combined with recent technological changes and consequent increase in competitiveness, there is a pressing need to redefine the Product Lifecycle Management (PLM) approach. PLM needs to incorporate aspects that would enable the shift to this paradigm, such as enhanced collection and evaluation of information coming from production processes, distribution, retail, consumers, and collaboration in an extended enterprise context, by implementing enabling technologies such as the Internet of Things (IoT) and Big Data. This paper proposes a vision, based on the state of the art, for a CE enabled PLM, having the Portuguese footwear industry scenario as a reference. © IFIP International Federation for Information Processing 2017.
2017
Autores
Pinto, A; JETSJ, Universidade de Lisboa,; Freire, AC; Cristóvão, A; Correia, AA; Gomes Correia, A; Fortunato, E; Machado do Vale, JL; Neves, J; Barroso, M; Parente, M; Laboratório Nacional de Engenharia Civil,; JETSJ,; Universidade de Coimbra,; Universidade do Minho,; Laboratório Nacional de Engenharia Civil,; Carpitech,; Universidade de Lisboa,; Laboratório Nacional de Engenharia Civil,; INESC TEC,;
Publicação
Abstract
2017
Autores
Sandim, M; Fortuna, P; Figueira, A; Oliveira, L;
Publicação
COMPLEX NETWORKS & THEIR APPLICATIONS V
Abstract
Social networks are becoming a wide repository of information, some of which may be of interest for general audiences. In this study we investigate which features may be extracted from single posts propagated throughout a social network, and that are indicative of its relevance, from a journalistic perspective. We then test these features with a set of supervised learning algorithms in order to evaluate our hypothesis. The main results indicate that if a text fragment is pointed out as being interesting, meaningful for the majority of people, reliable and with a wide scope, then it is more likely to be considered as relevant. This approach also presents promising results when validated with several well-known learning algorithms.
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