1,720,961 research outputs found
DUALITY IN DYNAMIC PROGRAMMING
No full textDuality is one of the most elegant and useful concepts in mathematics. However, there have been very limited duality results and no unified theory for dynamic programming. This dissertation develops duality for dynamic programming from two points of view. For dynamic programming problems with linear transition functions a duality is developed through the use of conjugate functions and convolution. This procedure is shown to mitigate the curse of dimensionality for primal problems with multidimensional state spaces. Numerical examples illustrate the computational advantages of the dual solution procedure. Secondly, a dual method is derived for the shortest route problem, which is the prototype dynamic programming problem. This duality is developed through the use of submodular functions and polymatroids. The duality is dependent on polymatroid intersection and the ability to write the functional equation for the shortest route problem as a submodular convolution function. The submodular method is shown to be polynomial for both the dual and the primal problems. Suggestions for extensions of this work and topics for future research in related areas are also discussed
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
Optimal inventory policies for profit maximizing EOQ models under various cost functions
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
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
Optimal inventory policies for an economic order quantity model with decreasing cost functions
No full textDispelling 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
A new algorithm for fuzzy multicriteria decision making
No full textAbstractAn algorithm for fuzzy multicriteria decision making is developed that allows the use of linguistic ratings as well as numeric ratings. This algorithm is based on and maintains the advantages of weighted-average rating methods and implied conjunction methods. The proposed algorithm is tested against another method and is shown to be precise and efficient
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