1,720,958 research outputs found
Probabilistic topic models for sequence data
No full textProbabilistic topic models are widely used in different contexts to uncover the hidden structure in large text corpora. One of the main (and perhaps strong) assumption of these models is that generative process follows a bag-of-words assumption, i.e. each token is independent from the previous one. We extend the popular Latent Dirichlet Allocation model by exploiting three different conditional Markovian assumptions: (i) the token generation depends on the current topic and on the previous token; (ii) the topic associated with each observation depends on topic associated with the previous one; (iii) the token generation depends on the current and previous topic. For each of these modeling assumptions we present a Gibbs Sampling procedure for parameter estimation. Experimental evaluation over real-word data shows the performance advantages, in terms of recall and precision, of the sequence-modeling approaches. © 2013 The Author(s)
Probabilistic sequence modeling for recommender systems
No full textProbabilistic topic models are widely used in different contexts to uncover the hidden structure in large text corpora. One of the main features of these models is that generative process follows a bag-of-words assumption, i.e each token is independent from the previous one. We extend the popular Latent Dirichlet Allocation model by exploiting a conditional Markovian assumptions, where the token generation depends on the current topic and on the previous token. The resulting model is capable of accommodating temporal correlations among tokens, which better model user behavior. This is particularly significant in a collaborative filtering context, where the choice of a user can be exploited for recommendation purposes, and hence a more realistic and accurate modeling enables better recommendations. For the mentioned model we present a fast Gibbs Sampling procedure for the parameters estimation. A thorough experimental evaluation over real-word data shows the performance advantages, in terms of recall and precision, of the proposed sequence-modeling approach. Copyright © 2012 SciTePress - Science and Technology Publications
A semantic-based framework for supporting interaction and cooperation in content-based web3.0 applications
No full textIn this paper, we introduce principles and functional architecture of Borè, a novel semantic-based framework that truly realizes Web3.0 principles and tools for the next-generation Internet. In particular, we detail peculiar aspects of Borè, such as architecture, social cooperation and collaborative filtering, which capture relevant innovations due to the proposed framework
Enforcing interaction and cooperation in content-based web3.0 applications
No full textIn this paper we complement our previous contribution [2] where we introduced principles and functional architecture of Borè, a novel framework that truly realizes Web3.0 principles and tools for the next-generation Internet. In particular, in this paper, we provide a more comprehensive overview of Borè by detailing peculiar aspects, such as the query languages and the related operators that allow us to browse and query the graph-like structure underlying a typical Borè's view, and providing a complete case study on Borè in action that focuses on an application domain related to the University context. © 2012 Springer-Verlag Berlin Heidelberg
A new architectural paradigm for content-based web applications: Borè
No full textThe Web is an evolving system, which tries to adapt to the needs of users. The transition to Web2.0, and, currently, to Web3.0, are the expression of this trend: the goal is to focus on the leading role of the end user in Web browsing, which should be supported by adequate tools. In this paper, we propose Borè, an architectural paradigm for developing content-based web applications based on cooperative interaction, whose foundations are based on the principles of the model Web3.0. The proposed architecture is extremely innovative in three respects. The first one is the possibility of defining, organizing, storing, querying and displaying the information as customizable objects and relations: a notexpert user can create the Web that he/she may prefer. A second aspect is the realization of social networks (Social Cooperations), which spontaneously arise, through user resource sharing. Finally, there is the possibility of analyzing users' browsing activities, through learning tools that enable the user to enrich his/her Web browsing experience with new knowledge. © 2011 ACM
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
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