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Porto, Portugal

The Institute for Systems and Computer Engineering of Porto is a research & development institute located on the campus of the Faculty of Engineering of the University of Porto . INESC Porto is a private non-profit association, recognised as a Public Interest Institution and has been an Associate Laboratory since 2002. In 2011, the institute proposed a new broader structure for the Associate Laboratory, which was officially recognised by the Ministry of Science as INESC TEC .The purpose of INESC TEC is to act as an interface between the academic world, the world of industry and services and the public administration in Information Technologies, Telecommunications and Electronics . INESC TEC invests in Scientific Research and Technological Development, as well as in Advanced Training and Consulting, Technology Transfer and supports the Establishment of new Technology-based Companies.Present in 6 sites in the cities of Porto, Braga and Vila Real, INESC TEC incorporates 12 R&D Centres and one Associate Unit with complementary competences, always looking to the international market. INESC TEC brings together more than 800 researchers, of which around 300 have PhDs . Wikipedia.

Esteves L.P.,INESC Porto
Cement and Concrete Composites | Year: 2011

Superabsorbent polymers are hydrogels capable of absorbing considerable amounts of water without dissolving, and may have wide application in building materials. They were initially used in the concrete industry with high performance cement-based materials to limit the drop in internal relative humidity during the hydration process of cement. This assures the optimum development of the material properties and avoids both self-desiccation and autogenous shrinkage. The mechanisms involved in the kinetics between the hydrogel and water or pore fluid within the cement-based system are not fully understood. This paper addresses the absorption kinetics of superabsorbent polymers in water and synthetic pore solution. The physical state of particles selected from a superabsorbent polymer sample with a particle size distribution between 50 and 500 micrometers is examined by means of optical microscopy and subsequent image analysis. This method has proven to be an accurate technique for quantifying the absorption of water or fluid into the cross-linked structure of superabsorbent polymers. As a result, the size of the polymers particles has a significant effect on the absorption kinetics of these polyacrylate-based polymers. A model based on the well-known Fick's second law has been found to accurately express the physical or volumetric change within the fluid medium, after a spontaneous fluid uptake, which occurs upon submersion. An extension to this model is proposed to calculate the kinetics of absorption for a given particle size distribution. © 2011 Elsevier Ltd. All rights reserved. Source

Tenreiro MacHado J.A.,INESC Porto
Signal Processing | Year: 2012

In this paper a new method for the calculation of the fractional expressions in the presence of sensor redundancy and noise, is presented. An algorithm, taking advantage of the signal characteristics and the sensor redundancy, is tuned and optimized through genetic algorithms. The results demonstrate the good performance for different types of expressions and distinct levels of noise. © 2011 Elsevier B.V. Source

Brito P.Q.,INESC Porto
Computers and Education | Year: 2012

The tweens are a transitional age group undergoing deep physical and psychological transformations. Based on a thirteen-focus group research design involving 103 students, and applying a tweens-centered approach, the characteristics of SMS, IM, Internet, digital photos, electronic games, and email were analyzed. Categories such as moral issues, psychological and social consequences, problems/drawbacks, general benefits, and technical attributes synthesized the main characteristics attached to each form of digital technology. Their relative relevance was not gender dependent. Furthermore, tweens exhibited both metacognitive knowledge and personal epistemological observations associated with most of the digital technologies. © 2012 Elsevier Ltd. All rights reserved. Source

Machado J.A.T.,INESC Porto
Nonlinear Dynamics | Year: 2010

This study addresses the optimization of fractional algorithms for the discrete-time control of linear and non-linear systems. The paper starts by analyzing the fundamentals of fractional control systems and genetic algorithms. In a second phase the paper evaluates the problem in an optimization perspective. The results demonstrate the feasibility of the evolutionary strategy and the adaptability to distinct types of systems. © 2010 Springer Science+Business Media B.V. Source

Phulpin Y.,INESC Porto
IEEE Transactions on Power Systems | Year: 2012

This letter introduces a communication-free control scheme that allows wind generators connected by an HVDC-link providing inertia and primary frequency control services to the mainland system. The scheme consists of making the offshore and onshore frequency deviations proportional. It relies on frequency regulation at the offshore converter and dc voltage control with power and frequency droops at the onshore converter. This letter provides a mathematical formulation of the system and a discussion on application challenges related to the control scheme. © 2012 IEEE. Source

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