Ivo Anastácio

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In this paper, we compare different methods for the automatic assignment of geographic scopes to Web pages, based on placenames mentioned in the text. The methods under study are the Yahoo! Placemaker Web service, the hierarchy-based method originally proposed for the Web-a-Where system, the spatial overlap-based method originally proposed in the GIPSY(More)
Geotargeting is a specialization of contextual advertising where the objective is to target ads to Website visitors concentrated in well-defined areas. Current approaches involve targeting ads based on the physical location of the visitors, estimated through their IP addresses. However, there are many situations where it would be more interesting to target(More)
This paper presents an approach for categorizing documents according to their implicit locational relevance. We report a thorough evaluation of several classifiers designed for this task, built by using support vector machines with multiple alternatives for feature vectors. Experimental results show that using feature vectors that combine document terms and(More)
This paper addresses the challenging information extraction problem of linking named entities in text to entries in a knowledge base. Our approach uses supervised learning to (a) rank candidate knowledge base entries for each named entity, (b) classify the top-ranked entry as the correct disambiguation or not, and (c) group together the named entities(More)
Geo-temporal information is pervasive over textual documents, since most of them contain references to particular locations, calendar dates, clock times or duration periods. An important text analytics problem is therefore related to resolving the place names and the temporal expressions referenced in the texts, i.e. linking the character strings in the(More)
Wireless sensor networks (WSNs) are becoming bigger, and with this growth comes the need for new automatic mechanisms for initializations done by hand. One of those mechanisms is the assignment of addresses to nodes. Several solutions were already proposed for mobile ad hoc networks but they either (i) do not scale well for WSN; (ii) have no energy(More)
À memória do meu pai i Acknowledgments The conclusion of this work represents the end of a cycle that was only made possible with the support of various people, to whom I express my gratitude. First of all, I would like to thank Prof. Mário Figueiredo and Prof. Pedro Aguiar for having accepted to supervise my work and for their cooperation. I also thank(More)
A maioria dos documentos textuais, produzidos no contexto das mais diversas aplicações, encontra-se relacionado com algum tipo de contexto geográfico. Contudo, os métodos tradicionais para a prospecção de informação em colecções de documentos vêem os textos como conjuntos de termos, ignorando outros aspectos. Mais recentemente, a recuperação de informação(More)
The complexity and number of interconnected elements comprising today's networks have stressed the need for autonomic computing techniques. This need is even bigger in Wireless Sensor Networks, because sensor nodes should work continuously without operator intervention, i.e. have self-organiztaion and self-configuration algorithms. The first action that a(More)