1,720,955 research outputs found
Traveling wave solutions of competitive-cooperative Lotka-Volterra systems of three species
No full textOn Solutions of Diffusive Lotka-Volterra Systems
No full text本作品討論二物種與三物種擴散型洛特卡-佛爾特拉方程組。對二競爭物種組，雙曲函數法用來構建嚴密行進波解。在藤田型結果的基礎之上，發展共存位移法來找二合作物種組的爆破解(和廖嫻)。對競爭-合作混合型三物種組，我們用上下解法來構築行進波解的存在性。以廣義雙曲函數法，可以證明三競爭物種組有嚴密(和三村昌泰等人)和半嚴密行進波解(和裘愉生)。此外，藉由極大值原理，三競爭物種組的行進波解不存在性也可以建立。最終，我們證明由熱傳方程的解可以構造出三競爭物種擴散型組的解。更進一步工作包含如何研究由擴散項引發的長期共存，這是從熱傳方程的解構築出來之解所發現的有趣新現象。In the present work, we study diffusive Lotka-Volterra systems of two-species and three-species. For competitive systems of two species, the tanh method is applied to construct exact traveling wave solutions. Based on the Fujita-type results, the method of shifted coexistence is developed to find blow-up solutions of cooperative systems of two species (with Xian Liao). For competitive-cooperative and competitive systems of three species, we employ the method of super- and subsolutions to establish the existence of traveling wave solutions. By using the generalized tanh method, it is shown that exact (with M. Mimura et al.) and semi-exact (with Yu-Sheng Chiou) traveling wave solutions exist for competitive systems of three species. In addition, nonexistence of traveling wave solutions to competitive systems of three species is also established by the maximum principle. Finally, we show solutions to competitive systems of three species can be constructed from the solutions of the heat equation. Further investigations include how to study diffusion-enhanced long-term coexistence, which is an interesting new phenomenon discovered by means of the solutions constructed from the heat equation
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
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