1,721,048 research outputs found
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
Lifted Probabilistic Inference: An MCMC Perspective
Get PDFThe general consensus seems to be that lifted
inference is concerned with exploiting model
symmetries and grouping indistinguishable
objects at inference time. Since first-order
probabilistic formalisms are essentially tem-
plate languages providing a more compact
representation of a corresponding ground
model, lifted inference tends to work especially well in these models. We show that the
notion of indistinguishability manifests itself
on several dferent levels {the level of constants, the level of ground atoms (variables),
the level of formulas (features), and the level
of assignments (possible worlds). We discuss
existing work in the MCMC literature on ex-
ploiting symmetries on the level of variable
assignments and relate it to novel results in
lifted MCMC
A delayed column generation strategy for exact k-bounded MAP inference in Markov logic networks
No full textVariations 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
A Unifying Framework for Disjunctive Data Constraints with Applications to Reasoning under Uncertainty
Get PDFThesis (Ph.D.) - Indiana University, Computer Sciences, 2009Constraints on different manifestations of data are a central concept in numerous areas of computer science. Examples include mathematical logic, database systems (functional and multivalued dependencies), data mining (association rules), and reasoning under uncertainty (conditional independence statements). One is often interested in a process that derives all or most of the constraints that are entailed by a set of known ones, without the expense and error-proneness of repeatedly analyzing the data. This is what is generally known as the implication problem for data constraints. We present a theoretical framework for disjunctive data constraints and the associated implication problems based on the observation that many instances can be reduced to an implication problem for additive constraints on specific classes of real-valued functions. Furthermore, we provide inference systems and testable properties of classes of real-valued functions which imply the soundness and completeness of these systems. We also derive properties of classes of functions that imply the non-existence of finite, complete axiomatizations. The theoretical framework is applied to derive novel results in the areas of uncertain reasoning and graphical models
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
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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