1,720,956 research outputs found
A study on the residual stress and crystal growth of thermal barrier coatings
No full text학위논문(석사) - 한국과학기술원 : 무기재료공학과, 1995.2, [ [ii], 61 p. ]한국과학기술원 : 무기재료공학과
스퍼터링법으로 증착한 박막의 잔류응력 생성 원인 및 결정 방향성과의 관계
No full text학위논문(박사) - 한국과학기술원 : 재료공학과, 1999.8, [ xii, [114] p. ] thin films were deposited by reactive sputtering of an Y target in Ar and gas mixture. Intrinsic stresses and the Ar content in the films were measured by the sines quare psi method of x-ray diffraction and wavelength dispersive spectrometer, respectively. At low working pressures the films had high compressive stresses. As working pressure increased, compressive stress was relaxed. Ar content was high in the film that had high compressive stress. After annealing of the films at 700℃, the compressive stress was largely relaxed but Ar content remained unchanged. These results clearly showed that compressive stress in films was not caused by Ar entrapment as an impurity but by Ar bombardment. Intrinsic stress was almost independent of the /Ar flow ratio, showing that O bombardment was equal to Ar bombardment in affecting the intrinsic stress in films. The independence of intrinsic stress of /Ar flow ratio was explained by the concept of M_i\frac^{1}{2} θ ±(M_t^2 - M_i^2 sin ^2 θ)^\frac{1}{2}]/(M_i + M_t) instead of the Mt/Mi ratio, where is the atomic mass of the target material, is the atomic mass of the sputtering gas, and θ is the scattering angle. Cu thin films were deposited by bias sputtering and the film density was measured by grazing incidence x-ray reflectivity. The influence of the experimentally measured film density on residual stress, which previously few studies reported about, was investigated. Without bias voltage, the relative film density was low and the tensile stress was high. With increasing bias voltage, tensile stress decreased and saturated to nearly zero at a bias voltage of -100 V while the film density increased and saturated to nearly bulk value at a bias voltage of -100 V. These results were consistent with those from previously reported molecular dynamic simulations. From the consideration of the Morse potential for relatively dense films, it was possible that tensile stress d...한국과학기술원 : 재료공학과
Spatial Charge Trap Engineering with Boron Nitride Barrier for 3D V-NAND Flash Memory
No full textSpatial charge trap engineering using amorphous boron nitride (BN) energy barrier for 3D V-NAND flash memory device is presented. A 1 nm thick BN layer is inserted within a silicon nitride (SiN) charge trap layer (CTL) using an In-situ ALD process. The CTL with the BN barrier located at an optimized position showed clear advantages in memory window and charge retention. The advantage of using the BN barrier becomes even more apparent when the CTL is scaled down to 4 nm, having more than 20% larger memory window, 44% improvement in hole retention, and more than 10 times faster erase speed compared to the same thickness of pure SiN CTL, which helps to advance XY-scaling in 3D V-NAND flash devices
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
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