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Alfonso J.,Aragon Institute of Technology | Rodriguez J.M.,Aragon Institute of Technology | Guerrero J.J.,Aragon Institute of Engineering Research
2015 European Control Conference, ECC 2015 | Year: 2015

The present paper proposes an iterative learning control (ILC) algorithm for accurate force tracking in a long range tribometer. The device is a nonlinear single input single output plant affected by repetitive and non repetitive perturbations in the output. The former perturbations result from the repetitive nature of the tests, and the latter ones are caused by friction phenomena in the guiding elements. Due to the characteristics of the device, it has been necessary to develop specific solutions to assure a robust behavior: on the one hand, analysis and identification techniques for the perturbations, and on the other hand, a spatial synchronization. The finally developed controller combines ILC with feedforward and feedback commands. The system is experimentally validated and the results show a substantial improvement in the performance compared to more classical approaches. © 2015 EUCA. Source

Martinez M.A.,Charles III University of Madrid | Velasco F.,Charles III University of Madrid | Abenojar J.,Charles III University of Madrid | Chiminelli A.,Aragon Institute of Technology | Breto R.,Aragon Institute of Technology
Journal of Adhesion | Year: 2015

The applications (and repair) of glass fiber reinforced epoxy composites are increasing in different industries (wind turbines, boats, chassis of buses, etc.) due to specific strength and low cost. Their major disadvantage is the difficulty to shape complex components. This problem can be solved manufacturing different parts, being adhesively bonded afterwards. This work studies the effect of atmospheric pressure plasma torch compared to grit-blasting to improve adhesion. After surface treating different parts, the changes of wettability and surface energy were measured. Treated samples were bonded with polyurethane and epoxy adhesives, and the quality of the bond was evaluated using pull-off adhesion tests and fracture strength test under cleavage loads. Obtained results allow to select the most adequate treatment in terms of mechanical requirements. Copyright © 2015 Taylor & Francis Group, LLC. Source

Garcia-Borgonon L.,Aragon Institute of Technology | Garcia-Borgonon L.,University of Seville | Barcelona M.A.,Aragon Institute of Technology | Barcelona M.A.,University of Seville | And 3 more authors.
Information and Software Technology | Year: 2014

Context Organizations working in software development are aware that processes are very important assets as well as they are very conscious of the need to deploy well-defined processes with the goal of improving software product development and, particularly, quality. Software process modeling languages are an important support for describing and managing software processes in software-intensive organizations. Objective This paper seeks to identify what software process modeling languages have been defined in last decade, the relationships and dependencies among them and, starting from the current state, to define directions for future research. Method A systematic literature review was developed. 1929 papers were retrieved by a manual search in 9 databases and 46 primary studies were finally included. Results Since 2000 more than 40 languages have been first reported, each of which with a concrete purpose. We show that different base technologies have been used to define software process modeling languages. We provide a scheme where each language is registered together with the year it was created, the base technology used to define it and whether it is considered a starting point for later languages. This scheme is used to illustrate the trend in software process modeling languages. Finally, we present directions for future research. Conclusion This review presents the different software process modeling languages that have been developed in the last ten years, showing the relevant fact that model-based SPMLs (Software Process Modeling Languages) are being considered as a current trend. Each one of these languages has been designed with a particular motivation, to solve problems which had been detected. However, there are still several problems to face, which have become evident in this review. This let us provide researchers with some guidelines for future research on this topic. © 2013 Elsevier B.V. All rights reserved. Source

Meier J.G.,Aragon Institute of Technology | Mrzel A.,Jozef Stefan Institute | Canales M.,Aragon Institute of Technology | Gonzalvo P.,Aragon Institute of Technology | Alcala N.,Aragon Institute of Technology
Physica Status Solidi (A) Applications and Materials Science | Year: 2013

Composites of Mo6S2I8-nanowires, MoO (3-x)-nanowires and MoS2-nanotubes with polyamide 6 (PA6) have been prepared in different concentrations up to 4% via melt-mixing using a laboratory twin screw extruder in order to investigate their tribological, mechanical and thermal properties. Chemical and structural composition of these nanowires and nanotubes with similar morphologies seem to play an important role in properties of fabricated polymer composites. Tribological tests were performed on the macroscale using a pin-on-disc (POD) tribometer and the thermal properties of the polymer nanocomposites were measured by differential scanning calorimetry to determine their glass transition temperatures and the levels of crystallinity. The behaviour of the nanowires (Mo6S2I 8 and MoO(3-x)) is different from the nanotubes (MoS 2) with respect to the induced effects on the friction coefficient and wear rate in function of concentration. The composites with the nanowires show a significant increase of the E-module of up to 38% at a nanowire concentration of 4 wt% in the glassy state of PA6, estimated from hardness measurements. The reduced friction coefficient and wear rates are related to the increased bulk shear strength of the nanowire polymer composites. In contrasts, nanotubes of MoS2 did not show this strong reinforcement. The reduced friction coefficients and wear rates of the polymer composites with MoS2-nanotubes are predominantly related to the lubricating effect of the MoS2-nanotubes at the contact points. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Hupont I.,Aragon Institute of Technology | Cerezo E.,University of Zaragoza | Baldassarri S.,University of Zaragoza
Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics | Year: 2010

The interpretation of user facial expressions is a very useful method for emotional sensing and it constitutes an indispensable part of affective Human Computer Interface designs. Facial expressions are often classified into one of several basic emotion categories. This categorical approach seems poor to treat faces with blended emotions, as well as to measure the intensity of a given emotion. This paper presents an effective system for facial emotional classification, where facial expressions are evaluated with a psychological 2-dimensional continuous affective approach. At its output, an expressional face is represented as a point in a 2D space characterized by evaluation and activation factors. The proposed system first starts with a classification method in discrete categories based on a novel combination of classifiers, that is subsequently mapped in a 2D space in order to be able to consider intermediate emotional states. The system has been tested with an extensive universal database and human assessment has been taken into consideration in the evaluation of results. ©2010 IEEE. Source

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