1,720,957 research outputs found
Stanovení zásad aplikace optimálních procesních kapalin pro obrábění
No full textPředložená disertační práce se zabývá studiem vybraných metod zkoušení procesních kapalin při třískovém obrábění. Na základě matematické analýzy pro následné porovnání navrhovaných experimentů byly provedeny dlouhodobé zkoušky trvanlivosti břitu nástroje při soustružení a frézování při třískovém obrábění u konstrukční a korozivzdorné oceli za použití deseti procesních kapalin od různých světových dodavatelů. Tyto dlouhodobé zkoušky byly porovnány metodou matematické statistiky se zkouškami krátkodobými laboratorními a tribologickými.Experimentálnímu výzkumu předchází rešerše zvolených používaných metod ke zkoušení procesních kapalin v průmyslu.Disertační práce má za cíl navrhnout možné zkrácení nákladů na zkoušení nově vyvinutých procesních kapalin.This dissertation deals with the study of selected methods of testing of process fluids in machining.On the basis of mathematical analysis and because of subsequent comparison of experiments of tests were conducted long-term tests of tool life, its cutting edge for turning and milling in machining with stainless construction steel by using ten process fluids from different suppliers worldwide. These long-term tests were compared according to the mathematical analysis with short-term laboratory and tribological tests.Experimental research is preceded by research of selected methods used for testing of process fluids in the industry.The dissertation aims to propose shortening the costs of testing newly developed process liquids
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Determination tool material for turning structural steel in firm ŠKODA-Auto, a.s.
No full textkatedra: KOM; rozsah: 61 s. (58 705)Currently a large number of cutting inserts is producing. Operators may be difficult to navigate in the selection of the best inserts. The situation is so complex that suppliers are still developing new brand inserts. Perform durability tests instruments are in practice very difficult, time consuming and expensive. The Department of machining and assembly of the Technical University of Liberec has been carried out research work for the comparison of durability inserts for turning steel used a 16 220. Were tested cermet inserts and cemented carbide inserts suppliers Sandvik Coromant, Sumitomo, Iscar, Seco, Walter and Widia. The result of research work was justified by the selection of optimal inserts. This article related to the project MSM 4674788501, which is supported by the Ministry of Education Czech Republic.V současnou dobu výrobce nástrojových materiálů vyrábí velký počet VBD. Provozovatelé se mohou jen těžko orientovat ve výběru nejlepší VBD. Situace je o to složitější, že dodavatelé vyvíjejí stále nové značky VBD. Provést zkoušky trvanlivosti nástrojů jsou v praxi velmi náročné, zdlouhavé a drahé. Na katedře obrábění a montáže TUL byla provedena výzkumná práce pro porovnávání trvanlivosti VBD při soustružení široce používané konstrukční oceli 16 220. Byly vyzkoušeny VBD z cermetu a slinutého karbidu od dodavatelů Sandvik Coromant, Sumitomo, Iscar, Seco, Walter a Widia. Výsledkem výzkumné práce byl zdůvodněn výběr optimálních VBD. Praktické výsledky výzkumu byly použity v průmyslu. Tento článek souvisí s řešením projektu MSM 4674788501, který je podporován MŠMT ČR
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Evaluation of Tribological Properties by Using Different Process Fluid by Test Ball on Disc
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