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Oliveira A.,University of Porto | Oliveira A.,Polytechnic Institute of Porto | Gaio A.R.,University of Porto | da Costa J.P.,University of Porto | And 2 more authors.
Advances in Intelligent Systems and Computing | Year: 2016

HIV/AIDS epidemic is an important public health problem. The burden of the epidemic is estimated from surveillance systems data. The collected information is incomplete, making the estimation a challenging task and the reported trends often biased. The most common incomplete-data problems, in this kind of data, are due to underdiagnosis and reporting delays, mainly in the most recent years. This is a classical problem for imputation methodologies. In this paper we study the distribution of AIDS reporting delays through a mix approach, combining longitudinal K-means with the generalized least squares method. While the former identifies homogeneous delay patterns, the latter estimated longitudinal regression curves.We found that a 2-cluster structure is appropriated to accommodate the heterogeneity in reporting delay on HIV/AIDS data and that the corresponding estimated delay curves are almost stationary over time. © Springer International Publishing Switzerland 2016. Source


Ferreira A.,University of Porto | Cardoso H.L.,University of Porto | Cardoso H.L.,Liacc Laboratorio Of Inteligencia Artificial E Ciencia Of Computadores | Reis L.P.,Liacc Laboratorio Of Inteligencia Artificial E Ciencia Of Computadores | Reis L.P.,University of Minho
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

The study of games in Artificial Intelligence has a long tradition. Game playing has been a fertile environment for the development of novel approaches to build intelligent programs. Multi-agent systems (MAS), in particular, are a very useful paradigm in this regard, not only because multi-player games can be addressed using this technology, but most importantly because social aspects of agenthood that have been studied for years by MAS researchers can be applied in the attractive and controlled scenarios that games convey. Diplomacy is a multi-player strategic zero-sum board game, including as main research challenges an enormous search tree, the difficulty of determining the real strength of a position, and the accommodation of negotiation among players. Negotiation abilities bring along other social aspects, such as the need to perform trust reasoning in order to win the game. The majority of existing artificial players (bots) for Diplomacy do not exploit the strategic opportunities enabled by negotiation, focusing instead on search and heuristic approaches. This paper describes the development of DipBlue, an artificial player that uses negotiation in order to gain advantage over its opponents, through the use of peace treaties, formation of alliances and suggestion of actions to allies. A simple trust assessment approach is used as a means to detect and react to potential betrayals by allied players. DipBlue was built to work with DipGame, a MAS testbed for Diplomacy, and has been tested with other players of the same platform and variations of itself. Experimental results show that the use of negotiation increases the performance of bots involved in alliances, when full trust is assumed. In the presence of betrayals, being able to perform trust reasoning is an effective approach to reduce their impact. © Springer-Verlag Berlin Heidelberg 2015. Source


Diogo P.,University of Minho | Reis L.P.,University of Minho | Reis L.P.,Liacc Laboratorio Of Inteligencia Artificial E Ciencia Of Computadores | Lopes N.V.,University of Minho | Lopes N.V.,University of Coimbra
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2014

Internet of Things (IoT) is seen as the future of Internet. We will step out from typical current communication paradigm, to a much wider spectrum, where normal 'things' will talk to each other, independent of human interaction. Emphasizing its importance in health industry, it can save lives and improve the ageing and disabled population's quality of living. It is not just things connected to the Internet - it is intelligent systems that we will be able to build on top of IoT that will introduce us to a better quality of life. However, IoT is facing a major problem: fragmentation and interoperability problems. If we want things to communicate with each other, intelligently and autonomously, then the new future Internet must be structured to allow such thing. The industry must adopt current standards and provide interoperability among other systems and developers must be aware of this issue too. Every new device should be IoT proof for future integration in IoT. In this article, there is a focus on these health-related use cases where they are detailed and explained how IoT could be deployed to aid in specific cases. The second part of the article takes the current IoT problem and tackles its issues, presenting a communication paradigm and proposes a new IoT system's architecture. © 2014 AISTI. Source


Lopes J.P.C.,University of Porto | Cardoso H.L.,University of Porto | Cardoso H.L.,Liacc Laboratorio Of Inteligencia Artificial E Ciencia Of Computadores
ICAART 2015 - 7th International Conference on Agents and Artificial Intelligence, Proceedings | Year: 2015

Multi-agent systems (MAS) present an effective approach to the efficient development of modular systems composed of interacting agents. Several frameworks exist that aid the development of MAS, but they are often not very appropriate for some kind of uses, such as for Multi-Agent-based Simulation (MABS). Other frameworks exist for running simulations, sharing little with the former. While open agent-based applications benefit from adopting development and interaction standards, such as those proposed by FIPA, most MABS frameworks do not support them. In this paper we propose an approach to bridge the gap between the development and simulation of MAS, by putting forward two complementary tools. The Simple API for JADE-based Simulations (SAJaS) enhances MABS frameworks with JADE-based features, and the MAS Simulation to Development (MASSim2Dev) tool allows the automatic conversion of a SAJaS-based simulation into a JADE MAS, and vice-versa. Repast Simphony was used as the base MABS framework. Our proposal provides increased simulation performance while enabling JADE programmers to quickly develop their simulation models using familiar concepts. Validation tests demonstrate the significant performance gain in using SAJaS with Repast Simphony when compared with JADE and show that using MASSim2Dev preserves the original functionality of the system. Copyright © 2015 SCITEPRESS - Science and Technology Publications All rights reserved. Source


Ferreira D.C.,University of Minho | Reis L.P.,University of Minho | Reis L.P.,Liacc Laboratorio Of Inteligencia Artificial E Ciencia Of Computadores | Lopes N.V.,University of Minho | Lopes N.V.,University of Coimbra
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2014

Nano-communications have tremendous potential for applications in the biomedical, environmental, industrial and military fields. Molecular communication is a new communication paradigm which allows nanomachines to exchange information using molecules as carrier. This is the most promising communication method within nanonetworks, since using electromagnetic waves is not very likely due to the size of the nanomachines. In molecular communication, information is encoded onto molecules at senders and the molecules propagate to receivers in a controlled manner. This control is one of the most important challenges, and this paper will describe some solutions for molecular communication. Since molecular communication offers means to transport information-encoded molecules to receivers and allows biological and artificially-created components to communicate with each other, future applications for health care are discussed in this paper. Results are obtained from computerized simulation scenarios selecting appropriate parameters for optimal performance. © 2014 AISTI. Source

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