1,721,023 research outputs found
Hybrid quantum-classical algorithms and error mitigation
Get PDFThese days, research groups such as Google, Microsoft, and Rigetti are working towards fabricating quantum devices which have hundreds to thousands of qubits. In recently proposed quantum algorithms, i.e. hybrid quantum-classical algorithms, such quantum devices are used as subroutines for calculation of classically intractable tasks. However, the applicability of hybrid algorithms was quite limited, for example, the search of the ground state, and simulation of the dynamics of quan- tum systems. In addition, near-term quantum devices are expected to be quite noisy, impairing the precision of computation seriously and removing any potential advantages with quantum computers. Therefore, it is necessary to extend the applicability of hybrid algorithms and mitigate errors on quantum computers. In this thesis, we describe the generalisation of hybrid algorithms so that they can be applied to variety of problems, such as search of the spectrum of quantum systems, simulation of open quantum systems and even general mathematical tasks. The algorithm for finding spectra is useful for applications such as new drug discovery, design of batteries. Generally speaking, quantum systems of interest to physicists, chemists, and materials scientists inevitably interact with their environments, and quantum states are decohered. Therefore, to investigate quantum phenomena, new algorithms simulating open quantum systems are described in this thesis. Algorithms for general mathematical tasks such as matrix multiplication to a vector and solving linear equations, useful for a large number of problems, such as machine learning, are also presented. Furthermore, in order to make hybrid algorithms useful, we also invented a practical error mitigation method for suppressing physical errors, which may make hybrid algorithms useful. We showed that errors can be suppressed for a quantum system with over 50 qubits for the current achievable error rate, which is believed to be hard to simulate with classical computers. Also, we generalised the error mitigation technique to be applied to mitigate algorithmic errors, which may enhance the accuracy of Hamiltonian simulation
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
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
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
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