1,721,449 research outputs found
NUMA obliviousness through memory mapping
No full textWith the rise of multi-socket multi-core CPUs a lot of effort is being put into how to best exploit their abundant CPU power. In a shared memory setting the multi-socket CPUs are equipped with their own memory module, and access memory modules across sockets in a non-uniform access pattern (NUMA). Memory access across socket is relatively expensive compared to memory access within a socket. One of the common solutions to minimize across socket memory access is to partition the data, such that the data affinity is maintained per socket.In this paper we explore the role of memory mapped storage to provide transparent data access in a NUMA environment, without the need of explicit data partitioning. We compare the performance of a database engine in a distributed setting in a multi-socket environment, with a database engine in a NUMA oblivious setting. We show that though the operating system tries to keep the data affinity to local sockets, a significant remote memory access still occurs, as the number of threads increase. Hence, setting explicit process and memory affinity results into a robust execution in NUMA oblivious plans. We use micro-experiments and SQL queries from the TPC-H benchmark to provide an in-depth experimental exploration of the landscape, in a four socket Intel machine.<br/
Lazy Pete [music] : march intermezzo on the famous melody 'Brummel Petrus' /
No full textB.1740 (Publisher number). For piano.; Caption title.; Pl. no : B.1740.; Also available online http://nla.gov.au/nla.mus-an10824483
Lazy Pete [music] /
No full textB.1740 (Publisher number). For voice and piano.; Caption title.; Pl. no. : B.1740.; "Novelty piano solo"--Cover.; "New edition with vocal version"--Cover.; Also available online http://nla.gov.au/nla.mus-vn3420981
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
Synthesis of Highly Functionalized Anthraquinones and Evaluation of Their Antitumor Activity
No full textHighly functionalized anthraquinones which derive from the natural products mensacarcin, islandicin, and chrysophanol have been efficiently synthesized using a Diels-Alder reaction as key step. The introduction of the proposed pharmaco-phoric side chain unit has been achieved by an addition of an aryllithimn species onto different aldehydes. Furthermore, the antitumor activity of these novel compounds has been studied by the in vitro growth inhibition of human lung carcinoma cells of line A549. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
First Total Synthesis of the Bioactive Anthraquinone Kwanzoquinone C and Related Natural Products by a Diels–Alder Approach
No full textThe first total synthesis of the novel anticancer agent kwanzoquinone C (1), an anthraquinone glycoside which has been isolated from extracts of the roots of orange daylilies (Kaempfer) (Hemerocallis fulva) is reported. The strategy involves the preparation of the tetrasubstituted 1,3-butadiene 6 by an electrocyclic conrotatory ring opening of the cyclobutanone rac-11, which is obtained by a [2+2] cycloaddition. Diels-Alder reaction of 6 with the juglone derivative 5 gives the bis-benzyl-protected anthraquinone 4 after aromatization. Finally, glycosidation of the phenolic hydroxy group using 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl trichloroacetimidate followed by the cleavage of the benzyl ethers and the solvolysis of the acetate groups yields the natural product 1. A related anthraquinone natural product 2 with antioxidative properties was obtained by using the 1,3-butadiene 17 and the juglone derivative 16 as substrates. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
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
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