1,720,990 research outputs found
Two-dimensional finite element approximation of the hexagonal bolt forming process
No full textIn cold forging industry, it is well known that deformation mechanism of the billet and forming tools should be known during forging to properly design the dies and estimate the tool life. Since three-dimensional simulations of forging the geometrically complex forged parts involve with large computation time and effort, two-dimensional (2D) axi-symmetric approximation might be beneficial for an initial die design and selection of the machine capacity and die material. In the present study such an approximation was made for the two-stage hexagonal bolt forming process of two different carbon steels for comparative study. For simulations, in-house rigid-viscoplastic finite element (FE) programs were used for the deformation analysis with 2D and 3D approaches with hexahedral and tetrahedral elements to compare computation time, load requirement, distributions of the effective strain and stress, and interface boundary die force among three cases. The elastic analysis of tools was also carried out for comparison. It was found out that the load values and strain distributions were similar between 2D and 3D simulation results. However, elastic stress distributions in lower dies for 2D and 3D cases showed a relatively reasonable difference incurring the variation of tool life. For 3D simulations hexahedral element was more effective under the present investigation condition. (C) 2007 Elsevier B.V. All rights reserved.This work was supported by the Korea Science and Engineer-
ing Foundation (KOSEF) through the National Research Lab.
Program funded by the Ministry of Science and Technology
(No. R0A-2006-000-10240-0
Effect of inclusion of dried distillers’ grains with solubles on the growth performance and immune responses of broilers
No full textTemporal effects of ganoderma lucidum myceliated grain on the growth performance and immune responses of broilers.
No full textGoing 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
High cycle fatigue life prediction of cold forging tools based on workpiece material property
No full textThe present investigation is focused on high cycle fatigue life prediction based on material property of the workpiece. A new approach based on industrial tool life data was introduced for estimation of fatigue properties of the tool material. The effect of the strength coefficient K and strain hardening exponent n of four different workpiece materials was included in the local stress and strain approach to derive a simple relationship between the high cycle fatigue life and material property of the workpiece. According to this relationship, a reasonably reliable high cycle fatigue tool life can be estimated. (C) 2007 Elsevier B.V. All rights reserved.The authors wish to thank for grants from POSCO and
National Research Laboratory Programs of the KOSEF and for
the technical data from Thaeyang Industry. The fellowship from
the Korea Research Foundation was much appreciated for the
Master work of the first author
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
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