1,720,961 research outputs found

    Sequences of Refinements of Rough Sets: Logical and Algebraic Aspects

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    In this thesis, a generalization of the classical Rough set theory [83] is developed considering the so-called sequences of orthopairs that we define in [20] as special sequences of rough sets. Mainly, our aim is to introduce some operations between sequences of orthopairs, and to discover how to generate them starting from the operations concerning standard rough sets (defined in [32]). Also, we prove several representation theorems representing the class of finite centered Kleene algebras with the interpolation property [31], and some classes of finite residuated lattices (more precisely, we consider Nelson algebras [87], Nelson lattices [23], IUML-algebras [73] and Kleene lattice with implication [27]) as sequences of orthopairs. Moreover, as an application, we show that a sequence of orthopairs can be used to represent an examiner’s opinion on a number of candidates applying for a job, and we show that opinions of two or more examiners can be combined using operations between sequences of orthopairs in order to get a final decision on each candidate. Finally, we provide the original modal logic SOn with semantics based on sequences of orthopairs, and we employ it to describe the knowledge of an agent that increases over time, as new information is provided. Modal logic SOn is characterized by the sequences (□ 1, ..., □ n) and (◯ 1, ..., ◯ n) of n modal operators corresponding to a sequence (t1, ..., tn) of consecutive times. Furthermore, the operator □ i of (□ 1, ..., □ n) represents the knowledge of an agent at time ti, and it coincides with the necessity modal operator of S5 logic [29]. On the other hand, the main innovative aspect of modal logic SOn is the presence of the sequence (◯ 1, ..., ◯ n), since ◯ i establishes whether an agent is interested in knowing a given fact at time ti

    How to merge opinions by using operations between sequences of orthopairs

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    Orthopairs are, analogously to rough sets, a mathematical tool for dealing with uncertainty. Sequences of orthopairs also take into account the possibility to deal with a refinement process of information and with missing information. After recalling the main definitions, we present different operations of conjunction between sequences of orthopairs. We further present an example in which, having available non complete information about applicants for a job, two examiners evaluate them in order to find the better candidates and then their opinions are merged into an individual result

    Discovery of interesting users in twitter by using rough sets

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    Twitter is today one of the most communication platforms and plays a key role as communications and news medium. This has driven most of companies to use Twitter for their advertisement campaign. So, it is crucial for them to have a strategy to individuate the advertisement targeting. In this article, we propose a Rough set-based methodology that analyzes the tweets posted by users during the weeks and interprets their needs and interests in order to disseminate the right advertisement to the right user in the right time

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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