1,724,302 research outputs found
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
Structural dimensions depending on light intensity in a 3D printing method that utilizes in situ light as a guide
No full textConventional 3D printing methods require the addition of a supporting layer in order to accurately and reliably fabricate the desired final product. However, the use of supporting material is not economically viable, and during the process of removing the supporting material, the shape or the properties of the final product may be distorted. In our previous work, we proposed and demonstrated the concept of a new 3D printing method that utilizes the in situ light as a guide for the fabrication of freestanding overhanging structures without the need for supporting material. In this study, the influence of the light intensity on the diameter of the structure and the thickness of the layer produced per droplet is analyzed in order to identify the geometric range of structures that can be fabricated by the new 3D printing method. As the intensity of the light increased, the diameter of the structure also increased and the thickness of the layer per droplet decreased. This result is determined by a combination of factors; (1) the rebound motion of the photocurable droplet and (2) the surface area of the structure that needs to be covered. © 2020, The Author(s).11Nscopu
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
Experiments on formation of the adiabatic shear band in sheet metal
No full textFormation of the adiabatic shear band in sheet metal is investigated with experiments for high strength steel sheets, 60 C and 60 TRIP. Since the adiabatic shear band is formed as a result of adiabatic shear failure with a narrow band of concentrated shear strain, the adiabatic shear band plays an important role in the analysis of high speed deformation phenomena. For shear band experiments with a tension split Hopkinson bar, specimens are designed to induce large shear strain. The experimental results show that the shear deformation modes of two sheet metals, 60 TRIP and 60 C, are quite different from each other in that the adiabatic shear band is observed only in 60 C. The shear deformation in 60 TRIP is restrained by the abrupt increase of strength due to the plastic strain, which interferes with propagation of the shear crack. Instead, a tensile crack developed at the corner where the shear crack should have been initiated. As a result, the load-displacement curves show that the tensile load of 60 TRIP specimens becomes higher than that of 60 C at the same displacement
Effect of Fibroblast Growth Factor-2 and Retinoic Acid on Lineage Commitment of Bone Marrow Mesenchymal Stem Cells
No full textIn this study, we examined the effect of a combination of fibroblast growth factor-2 (FGF-2) and retinoic acid (RA) on osteoblast and adipocyte lineage commitment and differentiation of human bone marrow mesenchymal stem cells (BMSCs). Pretreatment of human BMSCs with FGF-2 or RA for 5 days followed by osteoblast differentiation induction showed high calcium deposition compared to control. A combination of FGF-2 and RA further induced calcium deposition compared to FGF-2 or RA alone. The enhanced mineral deposition was accompanied with the increased expression of osteoblast differentiation markers, alkaline phosphatase and osteocalcin. On the other hand, FGF-2 pretreatment followed by adipocyte differentiation induction also showed increased formation of lipid droplets in human BMSCs, whereas RA pretreatment suppressed formation of lipid droplets. However, a combination of FGF-2 and RA increased formation of lipid droplets and expression of adipocyte marker genes, including adiponectin, ADIPOQ, FABP4, peroxisome proliferator-activated receptor gamma (PPAR gamma), and C/EBP alpha. During pretreatment of BMSCs with FGF-2, RA or in combination, the cells expressed similar levels of MSC surface markers such as CD29, CD44, CD90, and CD105, indicating that they maintain stem cell potential. To determine how RA cooperates with FGF-2 in osteoblast and adipocyte lineage commitment, the expression of RA receptors and intracellular lipid-binding proteins was examined. A combination of FGF-2 and RA strongly induced the expression of RA receptor alpha, beta, gamma, PPAR beta/delta, CRABP-II, and FABP5. Collectively, these results demonstrate that combined pretreatment of human BMSCs with FGF-2 and RA enhances the commitment into osteoblast and adipocyte lineages through modulation of the expression of RA-related genes.11sciescopuskc
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