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- Funções teste e funções generalizadas em dimensão 1. Descrição e caracterizaçãoPublication . Ferreira, Jorge; Gouveia, Délia; Reis, Maurício; Silva, José LuísNeste trabalho introduzimos uma família de espaços de funções teste definidas em R associadas à medida Gaussiana µ. Por dualidade obtemos a correspondente família de espaços de distribuições (ou funções generaliza das). A caracterização destas famílias à custa de funções inteiras com um certo tipo de crescimento é feita usando a transformada S. Como exemplo de aplicação apresentamos o produto de Wick entre funções generalizadas.
- Credibility-limited base revision: new classes and their characterizationsPublication . Garapa, Marco; Fermé, Eduardo; Reis, MaurícioIn this paper we study a kind of operator —known as credibility-limited base revisions— which addresses two of the main issues that have been pointed out to the AGM model of belief change. Indeed, on the one hand, these operators are defined on belief bases (rather than belief sets) and, on the other hand, they are constructed with the underlying idea that not all new information is accepted. We propose twenty different classes of credibility limited base revision operators and obtain axiomatic characterizations for each of them. Additionally we thoroughly investigate the interrelations (in the sense of inclusion) among all those classes. More precisely, we analyse whether each one of those classes is or is not (strictly) contained in each of the remaining ones.
- On ensconcement and contractionPublication . Fermé, Eduardo; Garapa, Marco; Reis, MaurícioIn this article we present an axiomatic characterization for the ensconcement-based contractions. We study the interrelation among ensconcement-based contractions and brutal contractions, and we present two ways of defining an ensconcement relation by means of a base contraction operation. Finally, we study the interrelations among ensconcement-based contraction and epistemic entrenchment-based contractions and among brutal contractions and severe withdrawals.
- How to construct remainder sets for paraconsistent revisions: preliminary reportPublication . Testa, Rafael; Fermé, Eduardo; Garapa, Marco; Reis, MaurícioRevision operation is the consistent expansion of a theory by a new belief-representing sentence. We consider that in a paraconsistent setting this desideratum can be accomplished in at least three distinct ways: the output of a revision op eration should be either non-trivial or non-contradictory (in general or relative to the new belief). In this paper those dis tinctions will be explored in the constructive level by showing how the remainder sets could be refined, capturing the key concepts of paraconsistency in a dynamical scenario. These are preliminaries results of a wider project on Paraconsistent Belief Change conduced by the authors.
- Choosing What to Believe - New Results in Selective RevisionPublication . Resina, Fillipe; Garapa, Marco; Wassermann, Renata; Fermé, Eduardo; Reis, MaurícioSelective Revision was proposed by Ferme and Hansson as ´ a belief revision operation in which it is possible to accept only a part of the input information. In this paper, we extend Selective Revision to belief bases and also to logics not closed under negation.
- Relevance, recovery and recuperation: a prelude to ring withdrawalPublication . Fermé, Eduardo; Garapa, Marco; Abhaya Nayak; Reis, Maurício D. L.; Reis, MaurícioIn this paper, we introduce recuperative withdrawals, belief change operators that satisfy recuperation, a postulate weaker than recovery, all the AGM postulates for contraction except recovery and another postulate which is a slightly stronger condition than conjunctive inclusion. Furthermore, we present a constructive definition for a class of operators —named ring withdrawals— which are such that the outcome of a ring withdrawal of a belief set 𝐊 by a sentence 𝛼 is obtained by adding to the set of most plausible models ‖𝐊‖ all the worlds which are as close to ‖𝐊‖ as its closest ¬𝛼-worlds. Ring withdrawals satisfy the Lindström and Rabinowicz’s interpolation thesis. We show that the classes of recuperative withdrawals and of ring withdrawals are identical. Additionally we show that the class of ring withdrawals is not contained in and does not contain the class of AGM contractions or the class of severe withdrawals. Finally we present methods for defining an operator of ring withdrawal by means of a severe withdrawal operator and by means of an AGM contraction operator, and vice-versa.
- Knowledge-driven profile dynamicsPublication . Fermé, Eduardo; Garapa, Marco; Reis, Maurício D. L.; Almeida, Yuri; Paulino, Teresa; Mariana Rodrigues; Garapa, Marco; Aristides da Silva Godinho de Almeida, Yuri; Fermé, Eduardo; Reis, Maurício; Paulino, TeresaIn the last decades, user profiles have been used in several areas of information technology. In the literature, most research works, and systems focus on the creation of profiles (using Data Mining techniques based on user’s navigation or interaction history). In general, the dynamics of profiles are made by means of a systematic recreation of the profiles, without using the previous profiles. In this paper we propose to formalize the creation, representation, and dynamics of profiles from a Knowledge-Driven perspective. We introduce and axiomatically characterize four operators for changing profiles using a belief change inspired approach.