1,722,623 research outputs found
Security in the 21st century: the United Nations, Afghanistan and Iraq
No full textContentsInternational terrorism; Operation Enduring Freedom; Political and economic reconstruction in Afghanistan; Pre-emptive strikes in the war on terror; Iraq, Kuwait and weapons of mass destruction; Operation Iraqi Freedom; Security Council reform and accountability
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
On the overall and delay complexity of the CLIQUES and Bron-Kerbosch algorithms
No full textWe revisit the maximal clique enumeration algorithm CLIQUES by Tomita et al. that appeared in Theoretical Computer Science in 2006. It is known to work in O(3n/3)-time in the worst-case for an n-vertex graph. This is worst-case optimal with respect to the input size, but there is little knowledge about its performance with respect to the output. In this paper, we extend the time-complexity analysis with respect to the maximum size and the number of maximal cliques, and to its delay, solving issues that were left as open problems since the original paper. In particular, we prove that CLIQUES has Ω(3n/6) delay and that, even if we allow to change the pivoting strategy, a variant having polynomial delay cannot be designed unless P=NP. These same results apply to the related Bron-Kerbosch algorithm. On the positive side, we show that the complexity of CLIQUES and Bron-Kerbosch is amortized polynomial on graphs with logarithmic clique number. As these algorithms are widely used and regarded as fast “in practice”, we are interested in observing their practical behavior: we run an evaluation of CLIQUES and three Bron-Kerbosch variants on over 130 real-world and synthetic graphs, observing how the clique number almost always satisfies our logarithmic constraint, and that their performance seems far from its theoretical worst-case behavior in terms of both total time and delay.
Constitutive equations to correlate uniaxial creep behaviour vs stress and temperature for inconel 718
Full text linkThe paper presents uniaxial creep tests conducted on Inconel 718 superalloy, reporting and describing the results obtained. The creep strain curves have been examined in different scenarios: by varying the initial applied stress, by varying the initial test temperature, and by considering the orientation of the specimens with respect to the direction of the material processing. Finally, ductility and deformation accumulation rate have been evaluated to highlight the effect of the precipitation anisotropy on the creep behaviour. Given the complexity of the creep phenomenon, each phase of the creep strain curves of Inconel 718 has been analysed independently, using constitutive models taken from the literature that allow to describe the phenomenon in pure metals and in some alloys
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