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Publications

2015

Governance mechanism in control architectures for flexible manufacturing systems

Authors
Jimenez, JF; Bekrar, A; Trentesaux, D; Zambrano Rey, GZ; Leitao, P;

Publication
IFAC PAPERSONLINE

Abstract
Manufacturing systems, and specifically Flexible Manufacturing Systems (FMS), face the challenge of accomplish global optimal performance and reactiveness at dynamic manufacturing environments. For this reason, manufacturing control systems must incorporate mechanisms that support dynamic custom-build responses. This paper introduces a framework that includes a governance mechanism in control system architectures that dynamically steers the autonomy of decision-making between predictive and reactive approaches. Results from experiments led in simulation show that it is worth studying in depth a governance mechanism that tailors the structure and/or behaviour of a manufacturing control system and, at the same time, potentiate the reactivity required in manufacturing operations.

2015

What Then Happens When Interaction is Not Possible: The Virtuosic Interpretation of Ergodic Artefacts

Authors
Carvalhais, M; Cardoso, P;

Publication
JOURNAL OF SCIENCE AND TECHNOLOGY OF THE ARTS

Abstract
Procedural systems allow unique modes of authorship and singular aesthetic experiences. As creators and users of these systems, we need to be aware that their aesthetic potential is not solely defined by interaction but that interpretation, and the capacity to understand and simulate the processes taking place within these artefacts is highly significant. This paper argues that although direct interaction is usually the most discernible component in the relationship between ergodic artefacts and their users, ergodicity does not necessarily imply interaction. Non-interactive procedural artefacts may allow the development of ergodic experiences through interpretation, and the probing of the system by its reader through simulations. We try to set the grounds for designing towards virtuosic interpretation, an activity that we may describe as the ergodic experience developed by means of mental simulation through the development of theories of systems.

2015

A special class of mixed constrained optimal control problems

Authors
De Pinho, MDR; Ferreira, MMA; Fontes, FACC;

Publication
2007 European Control Conference, ECC 2007

Abstract
The focus of this paper is on optimal control problems with mixed state and control inequality constraints. We identify a class of problems which can be associated with an auxiliary problem with both regular mixed constraints and pure state constraints. For that class of problems we derive a new set of necessary conditions of optimality. © 2007 EUCA.

2015

A Proactive Intelligent Decision Support System for Predicting the Popularity of Online News

Authors
Fernandes, K; Vinagre, P; Cortez, P;

Publication
PROGRESS IN ARTIFICIAL INTELLIGENCE

Abstract
Due to the Web expansion, the prediction of online news popularity is becoming a trendy research topic. In this paper, we propose a novel and proactive Intelligent Decision Support System (IDSS) that analyzes articles prior to their publication. Using a broad set of extracted features (e.g., keywords, digital media content, earlier popularity of news referenced in the article) the IDSS first predicts if an article will become popular. Then, it optimizes a subset of the articles features that can more easily be changed by authors, searching for an enhancement of the predicted popularity probability. Using a large and recently collected dataset, with 39,000 articles from the Mashable website, we performed a robust rolling windows evaluation of five state of the art models. The best result was provided by a Random Forest with a discrimination power of 73%. Moreover, several stochastic hill climbing local searches were explored. When optimizing 1000 articles, the best optimization method obtained a mean gain improvement of 15 percentage points in terms of the estimated popularity probability. These results attest the proposed IDSS as a valuable tool for online news authors.

2015

Potential of multi-temporal InSAR techniques for structural health monitoring

Authors
Lazecky, M; Bakon, M; Sousa, JJ; Perissin, D; Hlavacova, I; Patricio, G; Papco, J; Rapant, P; Real, N;

Publication
European Space Agency, (Special Publication) ESA SP

Abstract
In this paper it is clearly demonstrated that InSAR techniques may be particularly useful as a hot spot indicator of relative structures deformation over large areas, making it possible to develop interferometric based methodologies for SHM. Different case studies from structural health monitoring of buildings, bridges and highways and dams in Slovakia, Czech Republic, Hong Kong and Portugal processed within the scope of "RemotWatch - Alert and Monitoring System for Physical Structures" project using non-linear and other SHM-optimized algorithms of SARPROZ software, are reported. For the future investigation it is expected, that due to the faster product delivery of new missions (e.g. SENTINEL-1), it will be possible to deliver new workflows suitable for near-real time analysis aimed to better understanding of the deformation characteristics of the structures in urban and extra urban areas, important for structure stability and risk management applications.

2015

Electrosynthesis of heterocyclic compounds by radical cyclization in environmentally friendly media

Authors
Mendes, JP; Esperanca, JMSS; Esteves, AP; Silva, MM; Medeiros, MJ;

Publication
ECS Transactions

Abstract
We investigated the reductive intramolecular cyclization of bromopropargyl ethers derivatives, catalyzed by electrogenerated (1,4,8,11-tetramethyl-1,4,8,11-tetraaza-cyclotetradecane)nickel(I), [Ni(tmc)]+ as the catalysts in N,N,N-trimethyl-N-(2- hydroxyethyl)ammonium bis(trifluoromethylsulfonyl)imide,[N1112(OH)][NTf2] and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C2mim][NTf2] by cyclic voltammetry and controlled-potential electrolysis. The results show that the reaction leads to the formation of the expected cyclic compounds, which are important intermediates in the synthesis of natural products with possible biological activities. © The Electrochemical Society.

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