126,203 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Effet de barrières de potentiel sur le transport dans le graphène
No full textNational audienceL'énergie des porteurs de charge dans le graphène croît linéairement avec leur moment. Ce comportement fermionique de masse nulle, associé à l'absence de bande interdite entre électrons et trous, modifie profondément les propriétés de transport au travers de marches et de barrières de potentiel. Nous réalisons des mesures de transport dans une monocouche de graphène dont le profil de potentiel est modulé par un jeu de grilles locales [1,2]. En variant la hauteur et la largeur de la barrière de potentiel ainsi que l'énergie des porteurs, nous fournissons un test robuste des prédictions sur la transmission des canaux de conduction au travers d'une marche de potentiel dans le graphène. De plus, nous observons l'effet du désordre et de l'écrantage d'un champ extérieur dans le graphène. Ces expériences ont une application directe dans toute mesure de transport dans le graphène. En effet, nous avons montré que de telles marches de potentiel se développent naturellement à l'interface entre le graphène et une électrode métallique [3]. Nous discutons les effets de ces marches sur les mesures passées et futures [4]. [1] B. Huard, J.A. Sulpizio, N. Stander, K. Todd, B. Yang, D. Goldhaber-Gordon, Phys. Rev. Lett. 98, 236803 (2007) [2] N. Stander, B. Huard, D. Goldhaber-Gordon, condmat/0806.2319 [3] B. Huard, N. Stander, J.A. Sulpizio, D. Goldhaber-Gordon, Phys. Rev. B, 78, 121402 (R) (2008) [4] J. Cayssol, B. Huard, D. Goldhaber-Gordon, (to appear soon
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Performance analysis and implementation of Gauss-Huard elimination 1
No full textthis paper, we give a block algorithm for the Gauss-Huard elimination. For distributed memory systems, a performance analysis of this block algorithm is given and compared with results on two distributed memory systems: the MEIKO Computing Surface and the Parsytec#GCel. Results for Huard's algorithm on the MEIKO are compared with results for Gaussian elimination [Hoffmann91]. To reduce cache-operations in shared-memory systems, Hoffmann introduced a variant of the block Gauss-Huard algorithm: the twined block algorithm [Hoffmann93]. For this block algorithm, a performance analysis for shared-memory systems with cache is given. For large n, Gauss-Huard elimination may be faster than Gaussian elimination on shared memory computers. Further research is still going on. More work about the numerical stability and/or implementation of Huard's algorithm can be found in: [Huard76], [Cosnard86], [Dekker89], [Hoffmann89], [Potma89], [Dekker93], [Potma93] and [Rijnierse93]. Performance analysis and implementation of Gauss-Huard elimination 2 1 Gaussian and Gauss-Jordan elimination Given an n-th order non-singular matrix A and right-hand side vector b, we want to solve the linear system A x = b to obtain a result vector x. For this solution, Gaussian elimination is still the most popular method. With Gauss-Jordan elimination a diagonal matrix results. The main difference between Gaussian elimination and Gauss-Jordan is that the latter algorithm obtains the explicit inverse of matrix U by calculation of the factorisation. This has influences for the numerical stability of the Gauss-Jordan algorithm. Dekker et al. has in detail described the error analysis of both algorithms [Dekker93]. In this chapter we will give a short description of Gaussian and Gauss-Jordan elimination, becau..
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
Dr. Edwin Wright Collection: Author Unknown
No full textNotes - The author relates several short stories about his neighbours including Alex McDonell, homesteading and life around Meanook and Athabasca (1 page
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Anomalous energy exchanges and Wigner-function negativities in a single-qubit gate
No full textAnomalous weak values and the Wigner function's negativity are well-known witnesses of quantum contextuality. We show that these effects occur when analyzing the energetics of a single-qubit gate generated by a resonant coherent field traveling in a waveguide. The buildup of correlations between the qubit and the field is responsible for bounds on the gate fidelity, but also for a nontrivial energy balance recently observed in a superconducting setup. In the experimental scheme, the field is continuously monitored through heterodyne detection and then postselected over the outcomes of a final qubit's measurement. The postselected data can be interpreted as the field's weak values and can show anomalous values in the variation of the field's energy. We model the joint system dynamics with a collision model, gaining access to the qubit-field entangled state at any time. We find an analytical expression of the quasiprobability distribution of the postselected heterodyne signal, i.e., the conditional Husimi-Q function. The latter grants access to all the field's weak values: we use it to obtain that of the field's energy change and display its anomalous behavior. Finally, we derive the field's conditional Wigner function and show that anomalous weak values and Wigner function negativities arise for the same values of the gate's angle
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