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A Formulation of the Data Quality Optimization Problem in Cooperative Information Systems
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Fine-grain web site structure discovery
No full textSeveral techniques have been recently proposed to automatically derive web wrappers, i.e., programs that extract data from HTML pages, and transform them into a more structured format, typically in XML syntax. These techniques automatically induce a wrapper from a set of sample pages that share a common HTML template. An open issue, however, is how to collect suitable classes of sample pages to feed the wrapper inducer. Presently, the pages are chosen manually. In this paper, we tackle the problem of automatically discovering the main classes of pages offered by a site by exploring only a small, representative, portion of it. The web site model we propose describes the structure of the site as a graph whose nodes are classes of pages that share a common structure, and whose edges represent links among instances of the page classes. Using this model, we have developed an algorithm that accepts the url of an entry point to the target web site, visits a limited portion of the site, and produces an accurate model of the site structure. We also report on preliminary experiments performed on actual web sites, that have produced encouraging results.</p
Clustering Web pages based on their structure
No full textSeveral techniques have been recently proposed to automatically generate Web wrappers, i.e., programs
that extract data from HTML pages, and transform them into a more structured format, typically in XML.
These techniques automatically induce a wrapper from a set of sample pages that share a common HTML
template. An open issue, however, is how to collect suitable classes of sample pages to feed the wrapper
inducer. Presently, the pages are chosen manually. In this paper, we tackle the problem of automatically
discovering the main classes of pages offered by a site by exploring only a small yet representative portion
of it. We propose a model to describe abstract structural features of HTML pages. Based on this model, we
have developed an algorithm that accepts the URL of an entry point to a targetWeb site, visits a limited yet
representative number of pages, and produces an accurate clustering of pages based on their structure. We
have developed a prototype, which has been used to perform experiments on real-life Web sites
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Brokering infrastructure for minimum cost data procurement based on quality-quantity models
No full textInter-organization business processes involve the exchange of structured data across information systems. We assume that data are exchanged under given condition of quality (offered or required) and prices. Data offer may include bundling schemes, whereby different types of data are offered together with a single associated price and quality. We describe a brokering algorithm for obtaining data from peers, by minimizing the overall cost under quality requirements constraints. The algorithm extends query processing techniques over multiple database schemas to automatically derive an integer linear programming problem that returns an optimal matching of data providers to data consumers under realistic economic cost models
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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