28,381 research outputs found

    African Art: What and to Whom? Anxieties, Certainties, Mythologies

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    It has taken nearly a whole century to publish two books on African art that recognize the continent as a complex cultural unit within which there is diversity, A History of Art in Africa (Blackmun Visona, M et al, 2001) and Africa, The Art of a Continent (Phillips, T. 1995). Why it taken so long far North and East Africa past and present to be included in texts labeled African art? Why were they not recognized as African? India, also a place of diversity of race and ethnicity, has not similarly treated. The assumptions underlying the norms a representation of Africa were deeply rooted, their influence scholarship related to African art and culture was profound and, even if attenuated at present, persistent. They have impacted on the organization of information related to Africa, influencing from cataloging, the content of texts and videos, to museum layout exhibitions. Only by becoming conscious of the pervasive power of this hidden curriculum can we take steps to counter its influence. Those underlying assumptions are symptomatic of European fear5aJlII desires related to African identity

    Journalists' collective representation and editorial content in British newspapers- never the twain shall meet?

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    This article examines the propensity for journalists to contest the determination of the editorial content of the newspapers they work for and write for. It finds that such instances are relatively infrequent and suggests that not only is stronger workplace union organisation required to provide for the capability for journalists to do so but that a heightened level of trade union consciousness and abnormal occurrences in management practice are also required

    Improved Quantum Algorithm for Triangle Finding via Combinatorial Arguments

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    In this paper we present a quantum algorithm solving the triangle finding problem in unweighted graphs with query complexity O~(n5/4)\tilde O(n^{5/4}), where nn denotes the number of vertices in the graph. This improves the previous upper bound O(n9/7)=O(n1.285...)O(n^{9/7})=O(n^{1.285...}) recently obtained by Lee, Magniez and Santha. Our result shows, for the first time, that in the quantum query complexity setting unweighted triangle finding is easier than its edge-weighted version, since for finding an edge-weighted triangle Belovs and Rosmanis proved that any quantum algorithm requires Ω(n9/7/log⁥n)\Omega(n^{9/7}/\sqrt{\log n}) queries. Our result also illustrates some limitations of the non-adaptive learning graph approach used to obtain the previous O(n9/7)O(n^{9/7}) upper bound since, even over unweighted graphs, any quantum algorithm for triangle finding obtained using this approach requires Ω(n9/7/log⁥n)\Omega(n^{9/7}/\sqrt{\log n}) queries as well. To bypass the obstacles characterized by these lower bounds, our quantum algorithm uses combinatorial ideas exploiting the graph-theoretic properties of triangle finding, which cannot be used when considering edge-weighted graphs or the non-adaptive learning graph approach.Comment: 17 pages, to appear in FOCS'14; v2: minor correction

    Further Eastern Range Extension and Host Records for \u3ci\u3eLeptoglossus Occidentalis\u3c/i\u3e (Heteroptera: Coreidae): Well-Documented Dispersal of a Household Nuisance

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    Leptoglossus occidentalis is reported for the first time from Connecticut, New York, Ontario, Pennsylvania, and Wyoming, representing an eastern range extension from Indiana and Michigan. Tsuga canadensis and Pinus mugo are added to the long list of coniferous hosts of this coreid. Approximately 233 of 316 northeastern specimens were collected inside or on the outside of buildings from August-May, confirming previous observations that L. occidentalis uses buildings for overwintering. Isolated records from Con- necticut and eastern Pennsylvania suggest human-mediated dispersal may augment its natural dispersal. The pattern of distribution records on a map of North America identifies L. occidentalis as one of the best documented examples of a native insect expanding its range eastward in North America. Striking differences in the color pattern of the abdominal dorsum facilitates separation of the closely related L. occidentalis and L. corculus

    The University as an Industrial Plant: How A Workplace Theory of Discriminatory Harassment Creates a “Hostile Environment” for Free Speech in America’s Universities

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    Gall uses Rodney A. Smolla\u27s article Academic Freedom, Hate Speech, and the Idea of a University as a basis for his discussion of hostile environments for free speech among colleges and universities

    Faster Algorithms for Rectangular Matrix Multiplication

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    Let {\alpha} be the maximal value such that the product of an n x n^{\alpha} matrix by an n^{\alpha} x n matrix can be computed with n^{2+o(1)} arithmetic operations. In this paper we show that \alpha>0.30298, which improves the previous record \alpha>0.29462 by Coppersmith (Journal of Complexity, 1997). More generally, we construct a new algorithm for multiplying an n x n^k matrix by an n^k x n matrix, for any value k\neq 1. The complexity of this algorithm is better than all known algorithms for rectangular matrix multiplication. In the case of square matrix multiplication (i.e., for k=1), we recover exactly the complexity of the algorithm by Coppersmith and Winograd (Journal of Symbolic Computation, 1990). These new upper bounds can be used to improve the time complexity of several known algorithms that rely on rectangular matrix multiplication. For example, we directly obtain a O(n^{2.5302})-time algorithm for the all-pairs shortest paths problem over directed graphs with small integer weights, improving over the O(n^{2.575})-time algorithm by Zwick (JACM 2002), and also improve the time complexity of sparse square matrix multiplication.Comment: 37 pages; v2: some additions in the acknowledgment

    Powers of Tensors and Fast Matrix Multiplication

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    This paper presents a method to analyze the powers of a given trilinear form (a special kind of algebraic constructions also called a tensor) and obtain upper bounds on the asymptotic complexity of matrix multiplication. Compared with existing approaches, this method is based on convex optimization, and thus has polynomial-time complexity. As an application, we use this method to study powers of the construction given by Coppersmith and Winograd [Journal of Symbolic Computation, 1990] and obtain the upper bound ω<2.3728639\omega<2.3728639 on the exponent of square matrix multiplication, which slightly improves the best known upper bound.Comment: 28 page
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