1,721,579 research outputs found
Tests of discrete symmetries
Full text linkThis article provides a coarse-grained review on the experimental tests of fundamental discrete symmetries, focusing on those which appear to be deeply ingrained in nature, or at least rooted into the description of it which we are currently capable of providing, namely those related to space-time inversions and particle/anti-particle exchange. A broad selection of tests is discussed, not in the (vain) pursuit of completeness, but rather with the aim of providing an overview of the variety of approaches, and of the underlying common principles
Recent results on Kaon decays from NA48/2
No full textThe first observation of the K± → π±π0e+e− rare decay by the NA48/2 experiment at CERN SPS is reported, based on ∼ 2 ×1011 K± decays recorded in 2003-2004. From a sample of 4919 candidates with 4.9% background the branching ratio in the full kinematic region is measured to be BR(K± → π±π0e+e−) = (4.24 ±0.14) ×10−6. The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on Chiral Perturbation Theory. The CP-violating asymmetry between K+ → π+π0e+e− and K− → π−π0e+e− decay rates has been measured, providing an upper limit |ACP| < 4.82 ×10−2 at 90% CL. The NA48/2 combined measurement of the charged kaon semileptonic form factors, based on 4.4 million K± → π0e±νe and 2.3 million K± → π0μ±νμ events collected in 2004, is presented. This result represents the most precise form factor measurement from a combined Kl±3 analysis
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Full text linkWe 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
Artefacts, outils ou support épuisés? Une nouvelle approche pour l'étude des industries du paléolithique ancien: le cas d'Isernia La Pineta (Molise, Italie Centrale)
No full textIsernia La Pineta is one of the most important European Middle Pleistocene site. This paper focuses on the results of the experimental program compared with the data gathered during the study of the archaeological materials consisting in raw material analyses, lithic technology and functional analyses. Therefore the scenario which is proposed in this paper is extremely interesting and suggests a new and very different interpretation of the lithic assemblage of Isernia La Pineta which is viewed not only from a morphological standpoint, but is placed in a more articulate ecological context, probably closer to the living style of the human beings who first colonized Europe during the early Middle Pleistocene. The reconstruction of the lithic technological chain, from the choice of raw material and its procurement to production and use of the artifacts, seems to be suitable to open a new behavioural approach for a more ecological interpretation of the lithic assemblages meaning which belon..
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