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Guimarães, Portugal

Taivan C.,Centro Algoritmi
PerDis 2015 - Proceedings: 4th ACM International Symposium on Pervasive Displays | Year: 2015

In this paper, we discuss the case of an online service - The Knowledge Window, which helps in the dissemination of printed posters associated to a specific type of place, e.g., university. Our demo consists in a responsive web-based software that can assist people in the consumption of relevant information while being engaged into an embodied type of experience. The main goal of this demo is to provide an effective technology to foster information consumption right in the place and beyond. © 2015 ACM.

Cortez P.,Centro Algoritmi | Embrechts M.J.,Rensselaer Polytechnic Institute
Information Sciences | Year: 2013

In this paper, we propose a new visualization approach based on a Sensitivity Analysis (SA) to extract human understandable knowledge from supervised learning black box data mining models, such as Neural Networks (NNs), Support Vector Machines (SVMs) and ensembles, including Random Forests (RFs). Five SA methods (three of which are purely new) and four measures of input importance (one novel) are presented. Also, the SA approach is adapted to handle discrete variables and to aggregate multiple sensitivity responses. Moreover, several visualizations for the SA results are introduced, such as input pair importance color matrix and variable effect characteristic surface. A wide range of experiments was performed in order to test the SA methods and measures by fitting four well-known models (NN, SVM, RF and decision trees) to synthetic datasets (five regression and five classification tasks). In addition, the visualization capabilities of the SA are demonstrated using four real-world datasets (e.g., bank direct marketing and white wine quality). © 2012 Elsevier Inc. All rights reserved.

Marco A.B.,University of the Basque Country | Gozalvez C.,University of the Basque Country | Olano M.,University of the Basque Country | Sun X.,CIC Nanogune | And 6 more authors.
Physical Chemistry Chemical Physics | Year: 2016

The synthesis and characterisation of a pyrene-fused tetraazaheptacene that is constituted of two terminal pyrene units and a central tetraazaanthracene core are reported. The optoelectronic properties (experimental and calculated) of this heptacene derivative are discussed together with its charge transport properties in thin films. © 2016 The Owner Societies.

Garcia R.,University of the Basque Country | Melle-Franco M.,Centro Algoritmi | Mateo-Alonso A.,University of the Basque Country | Mateo-Alonso A.,Ikerbasque
Chemical Communications | Year: 2015

A pyrene-fused pyrazaacene with only four linearly-fused aromatic rings is reported, which remarkably shows emission at red to NIR wavelengths (λem = 687 nm). This exceeds the emission wavelengths observed for azaacenes with the same number of linearly-fused rings. © 2015 The Royal Society of Chemistry.

Fraga M.G.,University of Tras os Montes e Alto Douro | Varajao J.,University of Tras os Montes e Alto Douro | Amaral L.,Centro Algoritmi | Amaral L.,University of Minho | Bulas-Cruz J.,University of Tras os Montes e Alto Douro
Journal of Research and Practice in Information Technology | Year: 2012

The information systems outsourcing presents itself as a strategic option for companies and continues to evolve in size and in type of contracts. In order to identify the most frequently outsourced services and aiming to get a better comprehension on the hiring process, a study was made based on a survey sent to information systems managers of large Portuguese companies. The study allowed to identify the information systems services usually outsourced, the main criteria used for selecting suppliers, the aspects considered in contracts, the difficulties that arise in relationships between customers and suppliers, and the mechanisms adopted for conflict resolution. Copyright © 2012, Australian Computer Society Inc.

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