1,721,030 research outputs found
Defeasibility in contextual reasoning with CKR
No full textRecently, representation of context dependent knowledge in the Semantic
Web has been recognized as a relevant issue and a number of logic based
solutions have been proposed in this regard: among them, in our previous works
we presented the Contextualized Knowledge Repository (CKR) framework.
A CKR knowledge base has a two layered structure, modelled by a global context
and a set of local contexts: the global context not only contains the metaknowledge
defining the properties of local contexts, but also holds the global (context
independent) object knowledge that is shared by all of the local contexts. In many
practical cases, however, it is desirable to leave the possibility to “override” the
global object knowledge at the local level, by recognizing the axioms that can
allow exceptional instances in the local contexts. This clearly requires to add a
notion of non monotonicity across the global and the local parts of a CKR.
In this paper we present an extension to the semantics of CKR to introduce such
notion of defeasible axioms. By extending a previously proposed datalog translation,
we obtain a representation for CKR as a datalog program with negation
under answer set semantics. This representation can be exploited as the basis for
implementation of query answering for the proposed extension of CKR
Dagstuhl Seminar on the Foundations of Composite Event Recognition
No full textComposite event recognition (CER) is concerned with continuously matching patterns in streams of `event' data over (geographically) distributed sources. This paper reports the results of the Dagstuhl Seminar "Foundations of Composite Event Recognition" held in 2020
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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