1,721,101 research outputs found
Magnetronově naprašovaná tenkovrstvá kovová skla a jejich charakterizace
No full textV rámci této diplomové práce byla připravena tenkovrstvá kovová skla Zr-Cu kombinací metod vysokovýkonového pulzního magnetronového naprašování a DC magnetronového naprašování v Ar. Byl zkoumán vliv obsahu Cu ve vrstvách (0-100 at. % Cu), použitého napětí na substrátu (Us=Ufl, -30 V, -50 V, -70 V) a délky pulzu (100, 150 a 200 mikrosekund) na prvkové složení, strukturu, tepelné, mechanicke a povrchové vlastnosti a elektrickou rezistivitu vrstev Zr-Cu. Bylo zjištěno, že vrstvy Zr-Cu v rozsahu 30-83 at. % Cu vykazovaly amorfní strukturu. O tenkovrstvá kovová skla se jednalo v rozsahu složení 30-65 at. % Cu, přičemž velikost oblasti přechlazené kapaliny byla ~42°C. Dále bylo zjištěno, že u tenkovrstvého kovového skla Zr-Cu připraveného s hodnotou předpětí na substrátu Us=-50 V nebyly patrné smykové deformační pásy, což nasvědčuje zlepšenému plastickému chování vrstvy. V poslední řadě bylo zjištěno, že zkracováním délky pulzu dochází k nárůstu počtu defektů vytvořených ve vrstvách během depozice.ObhájenoThis thesis focuses on the preparation of Zr-Cu thin film metallic glasses deposited by HiPIMS and DC magnetron sputtering in pure argon. The influence of the coposition of the Zr-Cu thin films (0-100 at. % Cu), the value of substrate bias (Us=Ufl, -30 V, -50 V, -70 V) and the pulse duration (100, 150 and 200 microseconds) on the structure composition, structure, thermal, mechanical and surface properties and electrical resistivity has been analyzed. It was found that the Zr-Cu thin films are amorphous in the range of 30-65 at. % Cu. The Zr-Cu thin film metallic glasses was prepared in the range of 30-65 at. % Cu and the super-cooled liquid region was about ~42°C. There were discovered no shear bands in the Zr-Cu thin film metallic glasses prepared with the value of substrate bias Us=-50 V. This may be caused by improvements in plastic behavior of the thin film. Finally it was found that the number of defects formed in the layer during deposition increase with the shortening of the pulse duration
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
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
Market efficiency and automated trading
No full textThe dissertation thesis deals with the problem efficiency of the spot currency market. The main aim of this thesis is to verify the Efficient-market hypothesis on the majo foreign exchange pairs, and especially in the short term. The author focuses on the effective functioning of foreign exchange markets. The behaiour of the five main spot foreign exchange pairs - EUR/USD, GBP/USD, USD/CHF, USD/JPY and USD/CAD was analyzed in the thesis. Due to the increasing rise of intraday trades and growing popularity of margin accounts among retail investors, spot rates have been investigated primarily through a high-frequency data, that were collected for a period equal to or shorter than one day. The hypothesis of the effective exchange rate behaviour was verified by both using statistical methods, such as through automated trading systems, which were designed to assess the economic importance of the theory and to exclude or confirm the possibility of achieving above-average profits of retail investors on the foreign exchange markets
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