1,720,955 research outputs found
Influence of friction models on FE simulation results of orthogonal cutting process
No full textIt is well-known that the reliability of finite element
(FE) simulation results of cutting processes depends mainly
on two factors: implementation of a well-defined constitutive
model which can properly represent the severe deformation in
chip formation process as well as the viability of the relation
adopted to simulate the frictional condition at the tool-chip
interface. In the current study, a systematic approach is presented
to evaluate the performance of various friction models
in three different FE commercial codes: Deform 2D, Abaqus/
Explicit and AdvantEdge. The frictional condition was
analysed for two uncoated cemented carbide-plain carbon
steel combinations: K10/AISI 1045 and H13A/AISI 1080.
The results indicated that approximately similar ranges of
minimum average error in simulation responses can be
achieved, independently of the FE code used for simulation
of the chip formation process and for both tool-work material
combinations
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
A Combined Empirical and Numerical Approach for Tool Wear Prediction in Machining
No full textAbstractIn the present paper a combined empirical-numerical (finite element) approach for predicting the tool life has been introduced. This approach is based on the similarities found among the worn cutting edge geometries which have been obtained from the orthogonal tool life tests at different cutting speeds. The main difference between the proposed approach and those used in other finite element based tool wear prediction attempts is the lower computational time. Based on this approach finite element simulations of the cutting process based on worn tool geometries at several stages during the cut are run in parallel and provide the influential parameters on wear rate. Employing these parameters as input in the three well-known empirical wear rate equations, the relation between flank wear and cutting time are estimated. Predictions show agreement with experiment in terms of trend while some deviations exist in terms of the estimated magnitudes
Analysis of the Cutting Mechanics Under the Influence of Worn Tool Geometry
No full textAbstractIn machining, wear formation changes the effective geometry of the cutting edge which directly influences the mechanics of cutting. Analysis of the cutting mechanics and determination of the corresponding machining performance with a worn edge is of significant importance in terms of tool design, surface integrity, and process optimization. In the present study the effective geometry of the cutting edge was analyzed prior to cut by employing the circular regression method. Experimental cutting tests were performed and the effect of cutting time on the wear progression was investigated at several time intervals. The worn edge geometries were used to build the Arbitrary Lagrangian - Eulerian finite element cutting models in ABAQUS/Explicit. The models were validated by comparing the simulation results with the experimental findings of machining forces and chip thicknesses. The validated models were then employed to investigate the effect of wear geometry on the contact stresses, plastic deformation, and temperature distributions in the cutting zone
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
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