1,721,233 research outputs found
Robust economic optimization of process design under uncertainty
No full textIn this study, ranges of model parameters are analyzed for robustness measures. In particular, the properties of partial mean and worst-case cost in robust optimization are investigated. The robust optimization models are considered as multiobjective problems having two objectives, the expected performance (i.e. expected cost) and a robustness measure (Suh, M. and Lee, T. ( 2001) Robust optimization method for the economic term in chemical process design and planning. Industrial & Engineering Chemical Research, 40, 5950 - 5959). The robust partial mean model is defined with objectives of expected value and partial mean. The robust worst-case model is defined with the objective of expected value and worst-case. They are proved to guarantee Pareto optimality, which should be satisfied for multiobjective optimization problems. A graphical representation of the meaningful parameter ranges is clearly defined with mathematical proofs. The robustness of the solutions is discussed, based on the analysis of the ranges of the parameters. Three meaningful ranges of the parameters are investigated to choose a proper target value for the robust partial mean model. The worst-case value obtained from the worst-case analysis is recommended as the most effective target value, in order to obtain the optimal solution in a tradeoff between robustness and optimality. The proposed analysis in this study is validated with examples in chemical process design problems
Poly(5-((2-trimethylsilyl-2-propyl)oxycarbonyl)-norbornene-co-maleic anhydride) for 193-nm lithography
No full textA copolymer of 5-((2-trimethylsilyl-2-propyl)oxycarbonyl)-norbornene and maleic anhydride) was synthesized and evaluated as a chemically amplified resist for ArF lithography. The polymer has excellent transmittance at 193 nm and possesses good thermal stability up to 195 degrees C, whereas in the presence of an acid the cleavage of the 2-trimethylsilyl-2-propyl ester group begins at 76 degrees C in a catalytic manner. The 0.18 mu m line and space patterns were obtained at a dose of 10 mJ cm(-2) using an ArF excimer laser stepper. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.KAIST
Korea Science and Engineering Foundatio
Effect of rapid thermal annealing on the structure and the electrical properties of atomic-layer-deposited Ta2O5 films
No full textTantalum oxide films were grown using atomic layer deposition with the precursors of Ta(OEt)(5) and H2O on ITO and Si substrates at 300 degreesC. The changes of the structure and the electrical properties of the films were investigated fur various rapid-thermal-annealing (RTA) temperatures. The thicknesses and compositions were analyzed using Rutherford backscattering spectroscopy and were found to be invariable under our RTA processes of 500 similar to 700 degreesC. As-deposited and RTA-processed samples under 550 degreesC were amorphous and had a dielectric constant of epsilon (r)approximate to 24. For these specimens, the leakage current density for the [Al/Ta2O5/ITO] capacitors gradually decreased with increasing the annealing temperature and was as low as 5x10(-8) A/cm(2) at an electric field of 1 MV/cm. This improvement of the leakage current characteristics is thought to result from a reduction of impurities, such as hydrogen remaining in the films, as observed from the depth analysis of secondary ion mass spectroscopy. The films annealed above 600 degreesC showed a polycrystalline structure. This crystallization leads to an increase in the permittivity, up to 52, and a high leakage-current level
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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