1,721,342 research outputs found
Studies of Classical and Quantum Annealing
Full text linkA summary of the results of recent applications of PIMC-QA on different optimization problems is given in Chapter 1.
In order to gain understanding on these problems, we have moved one step back, and concentrated attention on the simplest textbook problems where the energy landscape is well under control: essentially, one-dimensional potentials, starting from a double-well potential, the simplest form of barrier. On these well controlled landscapes we have carried out a detailed and exhaustive comparison between quantum adiabatic Schrödinger evolution, both in real and in imaginary time, and its classical deterministic counterpart, i.e., Fokker-Planck evolution [17]. This work will be
illustrated in Chapter 2. On the same double well-potential, we have also studied the performance of different
stochastic annealing approaches, both classical Monte Carlo annealing and PIMCQA. The CA work is illustrated in Chapter 3, where we analyze the different annealing behaviors of three possible types of Monte Carlo moves (with Box, Gaussian, and Lorentzian distributions) in a numerical and analytical way. The PIMC-QA work is illustrated in Chapter 4, were we show the difficulties that a state-of-the-art PIMCQA algorithm can encounter in describing tunneling even in a simple landscape, and we also investigate the role of the kinetic energy choice, by comparing the standard
non-relativistic dispersion, Hkin = Tau(t)p^2, with a relativistic one, Hkin = Tau(t)|p|, which turns out to be definitely more effective. In view of the difficulties encountered by PIMC-QA even in a simple double-well potential, we finally explored the capabilities of another well established QMC technique, the Green's Function Monte Carlo (GFMC), as a base for a QA algorithm. This time, we concentrated our attention on a very studied and challenging optimization problem, the random Ising model ground state search, for which both CA and PIMC-QA data are available [10, 11]. A more detailed summary of the results and achievements described in this Thesis, and a discussion of open issues, is contained in the final section `Conclusions and Perspectives'. Finally, in order to keep this Thesis as self-contained as possible, we include in the appendices a large amount of supplemental material
Public action, the State and the handling of social problems. An introduction
Full text linkLos cientistas sociales destinamos tiempo y esfuerzo al estudio de teorías generales sobre el Estado. Lo hacemos en nuestra formación inicial, luego en el ejercicio de nuestro oficio. Sin dudas, incluimos al Estado en casi todos nuestros análisis. Pero rara vez realizamos una abordaje crítico, detallista, capaz de desnaturalizar el modo en que el Estado moldea el mundo social y cómo se articula con procesos sociales más generales.Fil: Barrault Stella, Lorenzo. Centre National de la Recherche Scientifique; FranciaFil: Lorenc Valcarce, Federico Mario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentina. Universidad Nacional de Mar del Plata; Argentin
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
