1,721,154 research outputs found
A Wait-Free Deque With Polylogarithmic Step Complexity
Get PDFThe amortized step complexity of operations on all previous lock-free implementations of double-ended queues is linear in the number of processes. This paper presents the first concurrent double-ended queue where the amortized step complexity of each operation is polylogarithmic. Since a stack is a special case of a double-ended queue, this is also the first concurrent stack with polylogarithmic step complexity. The implementation is wait-free and the amortized step complexity is O(log² p + log q) per operation, where p is the number of processes and q is the size of the double-ended queue
On Minimizing the Number of ADMs - Tight Bounds for an Algorithm Without Preprocessing
No full textMinimizing the number of electronic switches in optical networks is a main research topic in recent studies. In such networks we assign
colors to a given set of lightpaths. Thus the lightpaths are partitioned into cycles and paths. The switching cost is minimized when the number
of paths is minimized. The problem of minimizing the switching cost is NP-hard, and approximation algorithms have been suggested for it.
Many of these algorithms have a preprocessing stage, in which they first find cycles. The basic algorithm eliminates cycles of size at most l, and is known to have a performance guarantee of OPT + 0.5 (1 + eps)N, where OPT is the cost of an optimal solution, N is the number of
lightpaths, and 0<= eps <= 1/(l+2) , for any given odd l. Without preprocessing phase (i.e. l = 1), this reduces to OPT + 2/3 N. We develop a new
technique for the analysis of the upper bound and prove a tight bound of OPT + 3/5
N for the performance of this algorithm
On minimizing the number of ADMs in a general topology optical network
No full textAbstractMinimizing the number of electronic switches in optical networks has been a main research topic in some recent studies. In such networks, we assign colors to a given set of lightpaths, and they are partitioned into unicolor cycles and paths; the switching cost is minimized when the number of paths is minimized. Most approximation and heuristic algorithms for this problem have a preprocessing stage, in which possible cycles are found. Among them, the basic algorithm eliminates cycles of size at most l, and has a performance guarantee of OPT+12(1+ϵ)N, where OPT is the cost of an optimal solution, N is the number of lightpaths and 0≤ϵ≤1l+2, for any given odd l. The time complexity of the algorithm is exponential in l. We improve the analysis of this algorithm, by showing that ϵ≤132(l+2), which implies a reduction of the exponent in the time complexity. We also improve the lower bound by showing that ϵ≥12l+3. The results shed more light on the structure of this basic algorithm. In addition, in our analysis we suggest a novel technique–including a new combinatorial lemma–to deal with this problem
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
Variations 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
Divrei Shalom collected studies of Shalom M. Paul on the Bible and the ancient Near East ; 1967 - 2005 = Divrê šālôm
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