1,721,106 research outputs found
Paths Among Points Inside a Simple Polygon (Extended Abstract)
No full text) Marek Chrobak Gopalakrishnan Sundaram y Abstract In this paper we consider two problems in finding paths among a set X of points inside a simple polygon P . First, given two distinguished points s; t 2 X, we provide an algorithm which finds a simple path from s to t with vertices in X that does not intersect P in O(m 2 n(m+ n)) time, where jP j = m and jXj = n. We also show that finding simple paths among arbitrary obstacles is NP-Complete. Secondly, we consider the problem of finding a hamiltonian traversal in X. We show that finding an arbitrary traversal is NP-Complete. Also, we provide a O(n 4 (n + m)) algorithm for finding a traversal in a spiral polygon. 1 Definitions and Notations Let P be a simple polygon and X a finite set of points in the interior of P . Let s; t 2 X . We say that L is a (s; X; t)-path in P if it starts at s, ends at t, all vertices of L belong X and L is entirely contained in P . If X and P are understood from context, we will call L a path fro..
Competitive Algorithms for Multilevel Caching and Relaxed List Update (Extended Abstract)
No full text) Marek Chrobak John Noga y Abstract We study the Relaxed List Update Problem (RLUP), in which access requests are made to items stored in a list. The cost to access the jth item x j is c j , where c i c i+1 for all i. After the access, x j can be repeatedly swapped, at no cost, with any item that precedes it in the list. This problem was introduced by Aggarwal et al [1] as a model for the management of hierarchical memory that consists of a number of caches of increasing size and access time. They also proved that a version of LRU is C-competitive, for some C, for a restricted class of cost functions. (1) We give an efficient offline algorithm that computes the optimal strategy for RLUP. We also show an elegant characterization of work functions for RLUP. (2) We prove that Move-to-Front (MTF) is optimally competitive for RLUP with any cost function. An interesting feature of the proof is that it does not involve any estimates on the competitive ratio. (3) We give a lower boun..
Page Migration Algorithms Using Work Functions (Extended Abstract)
No full text) Marek Chrobak 1? Lawrence L. Larmore 1? Nick Reingold 2?? Jeffery Westbrook 3??? 1 Department of Computer Science, University of California, Riverside, CA 92521. 2 AT&T Bell Laboratories, Murray Hill, NJ 07974-0636. 3 Department of Computer Science, Yale University, New Haven, CT 06520-2158. Abstract. The page migration problem is the management problem for a globally addressed shared memory in a multiprocessor system. Each physical page of memory is located at a given processor, and memory references to that page by other processors incur a cost equal to the network distance. At times the page may migrate between processors, at a cost equal to the distance times the page size factor, D. The problem is to schedule movements on-line so as to minimize the total cost of memory references. We consider the problem under the restriction that movement can only occur after a request has been served and before the next request is known. The major results are: we give randomized (..
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
Dispelling 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
