1,720,990 research outputs found
Semantic Web Service Composition in the NeP4B Project: Challenges and Architectural Issues
No full textSemanticWeb service discovery and composition frameworksproposed so far assume for the most part a centralized registry that holds information of all the Web services available at any given time. This solution does not well cope with the scalability and flexibility requirements of dynamic, fast changing contexts. As part of the NeP4B project, in this paper we propose an alternative peer to peer architecture based on the Goal concept
Semantic Routing for Effective Search in Heterogeneous and Distributed Digital Libraries
No full textNext generation Digital Libraries (DLs) will offer an entire ensemble of systems and services designed to help users to easily find and access the information they are looking for. However, much work is still required in order to achieve this vision. In this paper, we concentrate our attention on devising techniques allowing an effective routing of queries, which we think can be of the utmost importance in providing effective and efficient querying in heterogeneous and distributed DLs, identifying the best ways to navigate the available nodes and, thus, the documents (or their parts) which are most suitable to best answer the user needs. We describe a routing mechanism, which we call routing by mapping, in which the query is sent to the DL peers whose subnetworks best approximate the concepts required. To this end a distributed index mechanism is adopted, which we call Semantic Routing Index (SRI). We also present some exploratory experiments showing the effectiveness of the proposed approach
SRI@work: Efficient and Effective Routing Strategies in a PDMS
No full textIn recent years, information sharing has gained much benefit by the large diffusion of distributed computing, namely through P2P systems and, in line with the Semantic Web vision, through Peer Data Management Systems (PDMSs). In a PDMS scenario one of the most difficult challenges is query routing, i.e. the capability of selecting small subsets of semantically relevant peers to forward a query to. In this paper, we put the Semantic Routing Index (SRI) distributed mechanism we proposed in [6] at work. In particular, we present general SRI-based query execution models, designed around different performance priorities and minimizing the information spanning over the network. Starting from these models, we devise several SRI-enabled routing policies, characterized by different effectiveness and efficiency targets, and we deeply test them in ad-hoc PDMS simulation environments
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Fuzzy query languages for multimedia data
No full textThis chapter presents a fuzzy-based algebra, called SAMEW, to query multimedia objects. SAMEW allows for dealing within a common framework with several aspects relevant to similarity query processing as well as with the inherent imprecision that characterizes data, user requests and query results. Non-Boolean, namely fuzzy and similarity, predicates are used to rank tuples according to specific criteria. Complex multi-predicate queries can be formed by means of logical connectives, whose semantics is parameterized in order to adapt to specific scenarios. The same holds for the semantics of algebraic operators. These include properly extended traditional relational operators and new operators which allow threshold and best-matches queries to be easily expressed. A further important feature of SAMEW is the possibility of weighting both predicates and operands of algebraic operators so as to better fit user preferences/requirements. A working example dealing with Web data is used throughout the chapter to show the potentialities of SAMEW. Optimization issues are also briefly discussed.</jats:p
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