1,721,096 research outputs found
Proceedings of the Sixth ACM International Conference on Web Search and Data Mining, WSDM 2013, Rome
No full textThe volume contains the proceedings of the sixth ACM International Conference on Web Search and Data Mining (WSDM 2013) held on February 4-8, 2013, in Rome, Italy. As in the previous years, WSDM has attracted an impressive number of submissions tackling the most recent technical challenges in Web search and data mining, with an ever-growing interest in their social aspects. We received a total of 387 submissions from 36 countries and regions, out of which 73 were accepted for full paper publication in the proceedings, thus reaching an acceptance rate of 18.9%. The authors of the accepted papers are from 20 countries, spanning four continents - making this a truly international forum
Packing Cycles and Cuts in Undirected Graphs
No full textWe study the complexity and approximability of Cut Packing and Cycle Packing. For Cycle Packing, we show that the problem is APX-hard but can be approximated within a factor of O(log n) by a simple greedy approach. Essentially the same approach achieves constant approximation for “dense” graphs. We show that both problems are NP-hard for planar graphs. For Cut Packing we show that, given a graph G the maximum cut packing is always between α(G) and 2α(G). We then derive new or improved polynomial-time algorithms for Cut Packing for special classes of graphs
An evaluation of SimRank and Personalized PageRank to build a recommender system for the Web of Data
No full textThe Web of Data is the natural evolution of the World Wide Web from a set of interlinked documents to a set of interlinked entities. It is a graph of information resources interconnected by semantic relations, thereby yielding the name Linked Data. The proliferation of Linked Data is for sure an opportunity to create a new family of data-intensive applications such as recommender systems. In particular, since content-based recommender systems base on the notion of similarity between items, the selection of the right graph-based similarity metric is of paramount importance to build an effective recommendation engine. In this paper, we review two existing metrics, SimRank and PageRank, and investigate their suitability and performance for computing similarity between resources in RDF graphs and investigate their usage to feed a content-based recommender system. Finally, we conduct experimental evaluations on a dataset for musical artists and bands recommendations thus comparing our results with two other content-based baselines measuring their performance with precision and recall, catalog coverage, items distribution and novelty metrics
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
Constraint Orbital Branching
No full textOrbital branching is a method for branching on variables in integer
programming that reduces the likelihood of evaluating redundant, isomorphic
nodes in the branch-and-bound procedure. In this work, the orbital branching
methodology is extended so that the branching disjunction can be based on an
arbitrary constraint. Many important families of integer programs are structured
such that small instances from the family are embedded in larger instances. This
structural information can be exploited to define a group of strong constraints
on which to base the orbital branching disjunction. The symmetric nature of the
problems is further exploited by enumerating non-isomorphic solutions to instances
of the small family and using these solutions to create a collection of
typically easy-to-solve integer programs. The solution of each integer program in
the collection is equivalent to solving the original large instance. The effectiveness
of this methodology is demonstrated by computing the optimal incidence
width of Steiner Triple Systems and minimum cardinality covering designs
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
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