1,720,953 research outputs found

    Experimental Investigation of Adobe Structures with Digital Image Correlation

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    Adobe brick (or Mudbrick) is commonly used as a construction material for residential structures in the Southwest portion of the United States. Adobe bricks are formed from mud that is composed of sand, silt, clay and water that is further mixed with straw then allowed to dry in the open environment. The straw aids in providing reinforcement for the brick and helping the brick dry more evenly which in turn reduces the amount of shrinkage cracks. The final product is a strong, durable, heavy brick used in the construction of homes. While this practice of adobe brick construction has been around for centuries there is still a lot of unknowns regarding the mechanical properties of the bricks particularly at different material compositions, reinforcement levels and moisture contents. This research investigates the material properties of adobe through traditional material and structural testing and through the use of digital image correlation to measure surface strains of the test specimens. Three types of testing were completed: material tests measuring the compressive strength of brick prisms, material tests measuring the bending strength of small modulus of rupture specimens, and structural tests measuring the in-plane lateral load capacity of one quarter scale walls. In 3-D DIC, the measured object is photographed with a pair of digital cameras before, during and after a load event, and a stochastic pattern marked on the object is tracked from one set of images to the next such that a full field of displacements is derived. Major findings were: DIC was a valuable tool for measuring displacements and strains in adobe materials and structures. DIC was able to allow visualization of adobe material failure modes and failure progression. Fibers within adobe bricks allowed the material to reach large deformations prior to complete collapse. This was the first study to use DIC on multiple faces of compression specimens to measure deformations in order to determine Modulus of Elasticity (E). The value for Modulus of Elasticity for the adobe used in this project was between 39,000 and 51,000 psi, depending on the method of calculation. This material is based upon work supported in part by the National Science Foundation (NSF) under NSF Cooperative Agreement Number EEC-1449501. Any opinions, findings and conclusions, or recommendations expressed in this material are those of the author(s), and do not necessarily reflect those of the NSF

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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
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