339 research outputs found
On the use of optoelectronic motion registration systems in biomechanical analysis of strike techniques
No full textKashuba Vitaliy, Litvinenko Yurii, Vako Ilia. On the use of optoelectronic motion registration systems in biomechanical analysis of strike techniques. Journal of Education, Health and Sport. 2017;7(3):939-948. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.4546285
http://ojs.ukw.edu.pl/index.php/johs/article/view/7848
The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26.01.2017).
1223 Journal of Education, Health and Sport eISSN 2391-8306 7
© The Author (s) 2017;
This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland
Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium,
provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License
(http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited.
This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted,
non commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Received: 27.03.2017. Revised 28.03.2017. Accepted: 29.03.2017.
On the use of optoelectronic motion registration systems in biomechanical analysis of strike techniques
Vitaliy Kashuba, Yurii Litvinenko, Ilia Vako
National University of Ukraine on Physical Education and Sport Ukraine, Kyiv, Ukraine
Blak Sea National University named after Petro Mohyla, Nikolaev, Ukraine
Abstract
Topicality. Sports and technical skills, as an element of a holistic process of sports training, occupy one of the priority places in the overall structure of sports skills. The study, formation, improvement and development of the most rational models of sport technique are closely related to the use of modern video recording systems.
The task of the study is to analyse the knee strike technique, applied by the athletes of different qualifications with the help of "Qualisys" optoelectronic system.
Results of the research. Analysis of highly skilled athletes’ competitive activities shows that a knee strike is mainly used in close combat. Much less often such a strike can be put in a jump from a long or average distance. In our work, we have analysed the technique of right knee strike, performed from the starting position characteristic of close combat.
Conclusions. When studying the biokinematic structure of the knee strike technique, used by athletes of different qualification, differences in the dynamics of changes in the speed of the lower extremity joints on athlete’ impact side of were found, which indicates higher coordination of movements, performed by highly skilled athletes. Thus, regarding highly qualified athletes the peaks of the maximum speed of their ankle and knee joints coincide in time, contrary to the skilled athletes. The speed of the skilled athletes’ ankle and hip joints at certain times is higher than those of highly skilled. However, the maximum value of speed of the highly skilled athletes’ strike link, as a rule, is higher on average by 0.5 m ∙ s-1. The general patterns include the reduction of the resulting knee speed for athletes of different qualification at the time of strike performance in reference to the maximum values that precede the strike interaction.
Key words: strike technique; optoelectronic systems; video analysis
Biomechanical analysis of hook technique at close reach of athletes specializing in hand-to-hand combat
No full textKashuba Vitaliy, Litvinenko Yurii, Vako Ilia. Biomechanical analysis of hook technique at close reach of athletes specializing in hand-to-hand combat. Journal of Education, Health and Sport. 2017;7(4):1030-1041. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.4546535
http://ojs.ukw.edu.pl/index.php/johs/article/view/7849
The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26.01.2017).
1223 Journal of Education, Health and Sport eISSN 2391-8306 7
© The Author (s) 2017;
This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland
Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium,
provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License
(http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited.
This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial
use, distribution and reproduction in any medium, provided the work is properly cited.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Received: 03.04.2017. Revised 10.04.2017. Accepted: 25.04.2017.
Biomechanical analysis of hook technique at close reach of athletes specializing
in hand-to-hand combat
Vitaliy Kashuba, Yurii Litvinenko, Ilia Vako
National University of Ukraine on Physical Education and Sport Ukraine, Kyiv, Ukraine Blak Sea National University named after Petro Mohyla, Nikolaev, Ukraine
Abstract
Topicality. Today, according to many experts, one of the promising ways to solve the problem of improving the efficiency of athletes’ training is the development and mastering of their motor techniques, which is an important and integral component of a holistic system of sports training, as technique is one of the decisive factors determining athlete’s motor potential. The study, formation, improvement and development of the most rational models of sport technique are closely related to the use of modern video recording systems.
The task of the research is to analyse the hook technique at close reach of athletes who specialize in hand-to-hand combat.
Research methods. To achieve the set tasks, we have used such research methods as analysis of scientific and methodological literature as well as documentary materials, methods of registration and analysis of athlete's movements (system of video recording and analysis of athlete's movements, 3D recording of human movements "Qualisys Motion Capture"). The results obtained during the study have been processed using the methods of mathematical statistics.
Results of the research. The hook technique at close reach in hand-to-hand combat is conventionally divided into three phases: the initial position, the phase of swing or propulsion (movement of the hand hitting the opponent), as well as the phase of strike (impact). In each phase, separate tasks are solved, but all of them, one way or another, are aimed at developing maximum strength, achieving it at the time of impact with an accurate hit on target.
Conclusions. Modern video recording systems allow obtaining objective quantitative characteristics of the athlete's body movement, which fully satisfies the necessary metrological requirements for biomechanical analysis.
Experimental studies have shown that the hook technique at close reach is individual for athletes of different qualification. However, we have identified general trends inherent in this group of athletes. For example, we have established a premature peak of the speed increase in the hitting links before the strike (impact), which was characteristic of all qualified athletes. The obtained data allowed us to establish that for high-skilled athletes the velocity modules of their certain joints at different points in time may differ. However, there is a general dynamics of change in the resulting speed, which may be associated with a certain and established sequence of biolinks inclusion and joints extension during the hook.
Key words: strike or hook technique; optoelectronic systems; video analysis
"Re-creating" Tadeusz Konwicki’s fiction : "Little apocalypse" and Yurii Andrukhovych’s "Moscoviad"a
No full textOn the basis of a comparative analysis of the worlds presented in Moscoviada by Yurii Andrukhovych and in the Little Apocalypse by Tadeusz Konwicki the article demonstrates the meaning of "metaphorical translation". Using the category proposed by Joseph Brodsky, the author of the article shows how similar characters, who search for their identities, are presented in both books
Growth of nanoparticles in liquid medium using magnetron sputtering technique
No full textTitle: Growth of nanoparticles in liquid medium using magnetron sputtering technique Author: Josef Kučera Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This thesis investigates the preparation of platinum and platinum-ruthenium alloy nanoparticles using magnetron sputtering method on a liquid substrate. Polypropylene glycol with three different molecular weights of 425, 1000, and 4000 was chosen as the liquid substrate. The influence of the different viscosities of these substrates on the size and morphology of the nanoparticles produced in the magnetron was investigated. Dynamic light scattering and transmission electron microscopy methods were used to determine the size of the nanoparticles. Furthermore, the catalytic activity of the produced nanoparticles in an alkaline environment was investigated using the rotating disk electrode technique. Keywords: Nanoparticles, Magnetron Sputtering, Polypropylene glycol, Hydrogen Fuel Cells, Water Electrolyzers, Hydrogen oxidation/reduction reactions
George Yurii Shevelov as a master of academic writing
No full textУкраїнськомовні лінгвістичні праці Юрія Шевельова свідчать про нього як про яскраву авторську індивідуальність. У статті проаналізовано стильові та художні засоби, якими він послуговується, щоб дієвіше впливати на читачів. Зроблено висновок про актуальність його мовної практики для вдосконалення й уточнення сучасних норм українського наукового стилю.Ukrainian linguistic papers by George Yurii Shevelov are evidence of his outstanding author individuality. The article deals with analysis of some stylistic and expressive means, which he uses for more effective influence upon his readers. The conclusion of the study reveals that his language practice is topical for development and improvement of modern standards of Ukrainian academic discourse
George Yurii Shevelov as a master of academic writing
No full textУкраїнськомовні лінгвістичні праці Юрія Шевельова свідчать про нього як про яскраву авторську індивідуальність. У статті проаналізовано стильові та художні засоби, якими він послуговується, щоб дієвіше впливати на читачів. Зроблено висновок про актуальність його мовної практики для вдосконалення й уточнення сучасних норм українського наукового стилю.Ukrainian linguistic papers by George Yurii Shevelov are evidence of his outstanding author individuality. The article deals with analysis of some stylistic and expressive means, which he uses for more effective influence upon his readers. The conclusion of the study reveals that his language practice is topical for development and improvement of modern standards of Ukrainian academic discourse
Growth of nanoparticles in liquid medium using magnetron sputtering technique
No full textNázev práce: Růst nanočástic v kapalném prostředí technikou magnetronového naprašování Autor: Josef Kučera Katedra / Ústav: Katedra fyziky povrchů a plazmatu Vedoucí bakalářské práce: Mgr. Yurii Yakovlev, Ph.D., Katedra fyziky povrchů a plazmatu Abstrakt: Tato práce zkoumá přípravu nanočástic platiny a platino-rutheniové slitiny pomocí metody magnetronového naprašování na kapalný substrát. Jako použitý kapalný substrát byl zvolen polypropylenglykol se třemi různými molekulárními hmotnostmi 425, 1000 a 4000. U těchto substrátů bylo prozkoumáno, jak jejich rozdílná viskosita ovlivňuje velikost a morfologii nanočástic připravených v magnetronu. Pro určení velikosti nanočástic byly využity metody dynamického rozptylu světla a transmisní elektronové mikroskopie. Dále byla prozkoumána katalytická aktivita vytvořených nanočástic v alkalickém prostředí pomocí techniky rotační diskové elektrody. Klíčová slova: Nanočástice, magnetronové naprašování, polypropylenglykol, vodíkové palivové články, elektrolyzéry vody, vodíkové redoxní reakce.Title: Growth of nanoparticles in liquid medium using magnetron sputtering technique Author: Josef Kučera Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This thesis investigates the preparation of platinum and platinum-ruthenium alloy nanoparticles using magnetron sputtering method on a liquid substrate. Polypropylene glycol with three different molecular weights of 425, 1000, and 4000 was chosen as the liquid substrate. The influence of the different viscosities of these substrates on the size and morphology of the nanoparticles produced in the magnetron was investigated. Dynamic light scattering and transmission electron microscopy methods were used to determine the size of the nanoparticles. Furthermore, the catalytic activity of the produced nanoparticles in an alkaline environment was investigated using the rotating disk electrode technique. Keywords: Nanoparticles, Magnetron Sputtering, Polypropylene glycol, Hydrogen Fuel Cells, Water Electrolyzers, Hydrogen oxidation/reduction reactions.Department of Surface and Plasma ScienceKatedra fyziky povrchů a plazmatuMatematicko-fyzikální fakultaFaculty of Mathematics and Physic
Optimalizace svazků palivových článků pomocí ultrazvukového zvlhčovače.
No full textTitle: Optimization of the Performance of Fuel Cell Stacks Using an Ultrasonic Humidi- fier. Author: Martin Vaněk Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This work is concerned with the optimization of the performance of PEM hydrogen fuel cell stacks, a technology that opens up new possibilities for clean energy storage and restoration. We have hand-built a PEMFC open-cathode stack of 20 cells and measured its basic characteristics such as the j-V and j-P curves as well as the dependency of the temperature of the stack on power produced by the stack for constant power of the cooling fans. We have implemented and tested the performance of a new method for water and thermal management - the humidification of air via the use of an ultrasonic water fog generator. Several tests - measuring cooling efficiency, voltage variations between different cells, and j-V and j-P curves - were performed under different temperatures and with or without humidification. Keywords: fuel cell, self humidification, open cathode, performance 1Název práce: Optimalizace svazků palivových článků pomocí ultrazvukového zvlhčovače. Autor: Martin Vaněk Katedra: Katedra fyziky povrchů a plazmatu Vedoucí bakalářské práce: Mgr. Yurii Yakovlev, Ph.D., Katedra fyziky povrchů a plaz- matu Abstrakt: Tato práce se zabývá optimalizací výkonu svazků PEM palivových článků, technologie, která otevírá nové možnosti pro uskladnění a zpětnou výrobu elektrické energie. Sestavili jsme dvaceticelový sériový svazek PEM vodíkových palivových článků s otevřenou katodou a změřili jeho základní charakteristiky, jako jsou j-V a j-P křivky a také závislost teploty článku na výkonu, který produkuje za konstantního výkonu chladících větráků. Implementovali a otestovali jsme novou metodu pro správu vody a teploty článku - zvlhčování příchozího vzduchu pomocí ultrazvukového generátoru mlhy - a její vliv na výkon svazku. Provedli jsme několik testů - měření efektivity chlazení, variací v napětích na jednotlivých celách a j-V a j-V křivky - a to za různých podmínek, konkrétně při různých teplotách a se zvlhčováním či bez něj. Klíčová slova: palivový článek, samozvlhčování, otevřená katoda, výkon 1Department of Surface and Plasma ScienceKatedra fyziky povrchů a plazmatuMatematicko-fyzikální fakultaFaculty of Mathematics and Physic
Ukrainian Children’s Folk Clothing in the Artistic and Ethnographic Heritage of Yurii Pavlovych
No full textУ розвідці розглядається питання дитячого народного вбрання українців у доробку видатного українського етнолога Юрія Павловича (1872–1947). Його багата спадщина, що налічує тисячі замальовок українського народного побуту, вбрання, житла та краєвидів, досліджена й представлена у праці «Україна в типажах народних, краєвидах і архітектурі: художньо-етнографічна спадщина Юрія Павловича», що була видана в Інституті мистецтвознавства, фольклористики та етнології ім. М. Т. Рильського АН України (ІМФЕ ім. М. Т. Рильського) у 2010 році. Упродовж 1921–1934 років Ю. Павлович був постійним позаштатним співробітником Кабінету антропології та етнології ім. Хв. Вовка, збагачуючи напрацювання цієї установи докладним ілюстративним матеріалом. Частина малюнків і праць Ю. Павловича висвітлює питання дитячої одягової культури. Ці матеріали є надзвичайно цінними для вивчення дитячої субкультури, особливостей дитячого вбрання, його форм і специфіки. Прикметним є оригінальний погляд автора ілюстрацій, що фіксував малопомітні та нетипові деталі дитячого повсякдення. Для дослідження було залучено малюнки та рукописи Ю. Павловича з Архівних наукових фондів, рукописів та фонозаписів ІМФЕ ім. М. Т. Рильського (фонди 1 та 39). На основі виявлених замальовок здійснено спробу проаналізувати характерні риси та особливості саме дитячого вбрання, їх інформативне значення для вивчення дитячого народного одягу українців першої половини ХХ ст. Малюнки й матеріали відображають різноманітні аспекти дитячої одягової культури, її варіативність, усталені норми і трансформації як у традиційній, так і міській культурі, а саме в Києві. У виявлених замальовках є змога побачити кольори костюма, естетичний смак, традиції та тенденції у створенні одягу. Зафіксовані Ю. Павловичем типажі, елементи костюма й зовнішній вигляд виразно репрезентують локальну специфіку дитячого вбрання. Унікальні матеріали є цінним джерелом для вивчення народного одягу, а також питань щодо ролі дитини та дитинства в українській культурі.The article examines the issue of children’s folk clothing of Ukrainians in the work of the outstanding Ukrainian ethnologist Yurii Pavlovych (1872–1947). His rich heritage includes thousands of sketches of Ukrainian folk life, clothing, housing, and landscapes, are studied and presented in the work «Ukraine in Folk Types, Landscapes, and Architecture: Artistic and Ethnographic Heritage of Yurii Pavlovych» published by the M.T. Rylskyi Institute of Art Studies, Folkloristics, and Ethnology in 2010. From 1921 to 1934, Yurii Pavlovych worked as a permanent freelance employee of the Cabinet of Anthropology and Ethnology named after Khvedir Vovk, enriching the work of this institution with detailed illustrative material. Some of Yurii Pavlovych’s drawings and works highlight the issues of children’s clothing culture. These materials are extremely valuable for studying the children’s subculture, features of children’s clothing, its forms, and specifics. The original point of view of the author of the illustrations, who fixed the inconspicuous and atypical details of children’s everyday lives, is noteworthy. During the preparation of the research, drawings and manuscripts of Yurii Pavlovych involved from the Archival Scientific Funds of Manuscripts and Audio Recordings of the Maksym Rylskyi Institute of Art Studies, Folkloristics and Ethnology of the National Academy of Sciences of Ukraine (funds 1 and 39). Based on the discovered sketches, an attempt was made to analyse the characteristic features and peculiarities of children’s clothing, their informative value for the study of children’s folk clothing of Ukrainians in the first half of the XX century. Drawings and materials reflect various aspects of children’s clothing culture, its variability, established norms, and transformations in both traditional and urban culture, namely in Kyiv. In the discovered sketches, it is possible to see the colours of the costume, aesthetic taste, traditions, and trends in clothing creation. The types, costume elements, and appearance recorded by Yurii Pavlovych clearly represent the local specificity of children’s clothing. The unique materials are a valuable source for the study of folk dress, as well as questions about the role of the child and childhood in Ukrainian culture. Some of Yurii Pavlovych’s drawings are being published for the first time
Optimization of the performance of fuel cell stacks using an ultrasonic humidifier.
No full textTitle: Optimization of the Performance of Fuel Cell Stacks Using an Ultrasonic Humidi- fier. Author: Martin Vaněk Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This work is concerned with the optimization of the performance of PEM hydrogen fuel cell stacks, a technology that opens up new possibilities for clean energy storage and restoration. We have hand-built a PEMFC open-cathode stack of 20 cells and measured its basic characteristics such as the j-V and j-P curves as well as the dependency of the temperature of the stack on power produced by the stack for constant power of the cooling fans. We have implemented and tested the performance of a new method for water and thermal management - the humidification of air via the use of an ultrasonic water fog generator. Several tests - measuring cooling efficiency, voltage variations between different cells, and j-V and j-P curves - were performed under different temperatures and with or without humidification. Keywords: fuel cell, self humidification, open cathode, performance
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