• Title/Summary/Keyword: THROWING

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Kinematic Analysis of Elite Athletes in Men's Shot-Put at World Championships, Daegu 2011 (2011 대구세계육상선수권대회 남자 포환던지기 결선경기의 운동학적 분석)

  • Oh, Cheong-Hwan;Shin, Eui-Su;Choi, Su-Nam;Jeong, Ik-Su;Bae, Jae-Hee;Lee, Jeong-Tea;Park, Seung-Bum
    • Korean Journal of Applied Biomechanics
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    • v.21 no.5
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    • pp.631-638
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    • 2011
  • This study had two purposes. The first was to analyze the period of the final record set by the male shot-putters in the IAAF World Championships, Daegu 2011 from the point of view of kinematics. The other was to identify an efficient movement for shot putting based on the analysis. The research used the eight finalists of in the championship as subjects. We analyzed the seven most important kinematic factors in shot putting based on the type of technique: the execution time of the delivery phase, release velocity, release angle, release, center of mass (COM) velocity, and shot trajectories. The analytical results showed the following average figures for the record 12 meters: execution time of the delivery phase: (0.19 s), release height: (2.06 m), release angle: ($34.68^{\circ}$), release velocity: (13.25 m/s), angular velocity of shoulder: ($922.38^{\circ}/s$), and angular velocity of pelvis: ($479.50^{\circ}/s$). Further, the results showed that the highest COM velocity was 2.25 m/s and the shot trajectories were close to a straight line in the release phase.

Estimation of Drag Factors Between Roadway Surface and Human Body (인체와 노면간의 마찰계수 추정에 관한 연구)

  • Kim, Min-Tae;Lee, Sang-Soo;Lee, Chul-Ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.6
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    • pp.54-62
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    • 2010
  • The scientific analysis of car-pedestrian accidents is not an easy task because of the characteristic of the accidents itself. Since the analysis involved human being, there were few experimental data that could be used for the analysis. The coefficient of friction of human body was the one of crucial data for accident analysis, but no field experiment report was available for various roadway conditions. This study intends to measure the coefficient of friction of human body through field studies. Results showed that the coefficient of friction of human body for dry asphalt pavement conditions was 0.59~0.62, and for dry concrete pavement conditions was 0.59~0.61. In addition, the coefficients for wet asphalt pavement and for wet concrete pavement conditions were 0.56~0.59 and 0.51~0.54 respectively, indicating 5.0% and 8.3% reduction compared to the dry conditions. The deduced coefficients were validated using the simulation program. It has been confirmed that the experiment values were close to the simulation results.

An Exploration according to Clothing Category for Increasing the Sustainability of Fashion and Textiles (섬유의류산업의 지속가능성 증진을 위한 의복종류별 방안 모색)

  • Na, Youngjoo;Lee, Hyunkyu
    • Fashion & Textile Research Journal
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    • v.15 no.2
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    • pp.294-301
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    • 2013
  • Sustainable fashion & textile is more than eco fashion & textile with the concepts for the next generation's happiness, prosumer value, and community responsibility. This study considers methods to enhance fashion and textile industry sustainability in accordance to clothing types (material, product life and washing properties) and to investigate company strategies. Company strategies are of redesign with stock, volunteering & measuring trash amount, participation by evaluation stores, clerk environment education, hiring QC specialist and reinforcing partnerships. For the case of daily innerwear, throwing away and recycling is more efficient for the environment than laundering in the consumer use stage; subsequently, we recommend the use of polypropylene fiber (a cheap and an eco-friendly material) for this item that can be recycled and reformed after use. For the case of single layer clothing (such as sportswear, blouse or pants) we recommend the use of thermoplastic materials with welding or fuse assembling technology instead of a sewing method of seams as well as the recycle design that is simply melted and reformed into new clothing without an after use dissembling process. Secondhand use or resale is suitable for denim/jean items if the clothing has a storytelling or private history tag. Lastly, module-type jacket or coat shows the variety of styles with one clothing worn w/o collar or sleeve details and changed into vest/coat; in addition, it is possible to add or partly tear off some jacket/coat fibers of the felt material to reform it into a new design.

Development of a new thermal inkjet head with the virtual valve fabricated by MEMS technology (멤스기술을 이용한 가상밸브가 있는 새로운 잉크젯 헤드 개발)

  • Bae, Ki-Deok;Baek, Seog-Soon;Shin, Jong-Woo;Lim, Hyung-Taek;Shin, SuHo;Oh, Yong-Soo
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1892-1897
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    • 2003
  • A new thermal inkjet printer head on SOI wafer with virtual valve was proposed. It was composed of two rectangular heaters with same size. So we could call it T-jet(Twin jet). T-jet has a lot of merits. It has the advantage of being fabricated with one wafer and is easy to change the size of chamber, nozzle, restrictor and so on. However, above all, It is the best point that T-jet has a virtual valve. And it was manufactured on SOI wafer. The chamber was formed in its upper silicon whose thickness was 40um. The chamber's bottom layer was silicon dioxide of SOI wafer and two heaters were located underneath the chamber's ceiling. And the restirctor was made beside the chamber. Nozzle was molded by process of Ni plating. Ni was 30um thick. Nozzle ejection test was performed by printer head having 56 nozzles in 2 columns with 600NPI(nozzle per inch) and black ink. It measured a drop velocity of 12m/s, a drop volume of 30pl, and a maximum firing frequency of 12KHz for single nozzle ejection. Throwing out the ink drop in whole nozzles at the same time, it was observed that the uniformity of the drop velocity and volume was less than 4%.

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The Relationship between the Distance and Kinematical Parameters of Javelin in Korean Male Javelin Throwers (한국 남자 창던지기 선수들의 창의 운동학적 요인과 기록과의 관계)

  • Kim, Woo-Jin
    • Korean Journal of Applied Biomechanics
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    • v.24 no.3
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    • pp.217-227
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    • 2014
  • The purpose of this study was to investigate the relationship between distance and factors of javelin in korean male's javelin throwing. To accomplish this purpose, the analyzed trail selected total 29 trails (subjects 9) recorded more than 65 m in the 93rd National Sports Festival. The Kwon3D 3.1 version was used to obtain the three dimensional coordinates about the top, grip, end of javelin. And the kinematic data such as projection factors and direction angle of javelin calculated using Matlab2009a program. The statical analysis on the records (n=29) were used to Pearson's product moment correlation coefficient. There was a statistically positive relationship between the records and horizontal velocity (r=.866, ${\rho}$<.01), height (r=.541, ${\rho}$ <.001), height rate (r=.373, ${\rho}$ <.05) and horizontal displacement of javelin (r=.749, ${\rho}$ <.01), but the medial/lateral velocity showed a negative relationship to r=-.663 (${\rho}$ <.01). The attack and yaw angle showed not a significant relationship between the records, but the medial-lateral tilt (E1:r =-.557 [p<.01)] E2:r=-.629 [${\rho}$<.01], E3:r=-.528 [${\rho}$ <.01]) and attitude angle (E2:r=-.629 [[${\rho}$<.01], E3:r=-.619 [${\rho}$ <.01]) of javelin showed a negative relationship between the records, as well as the projection angle of javelin (r=-.419, ${\rho}$ <.05) showed a negative relationship between the records.

Effects of Joint Mobilization Intervention Combined with Exercise on Range of Motion, Pain Intensity, and Functional Performance in Adolescent Baseball Players with Internal Impingement of the Shoulder (운동과 관절가동술을 혼합한 중재가 어깨관절 내적 충돌증후군을 가진 청소년기 야구선수의 관절가동범위, 통증정도, 기능수행정도에 미치는 효과)

  • Oh, Tae-Young;Choo, Yeon-Ki;Yoo, Il-Young
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.2
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    • pp.11-19
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    • 2018
  • PURPOSE: The aim of this study was to identify the effects of joint mobilization intervention combined with exercise on range of motion (ROM), pain intensity, and functional performance in adolescent baseball players with internal impingement syndrome of the shoulder. METHODS: The subjects were 30 adolescent baseball players diagnosed with internal impingement. Ten subjects were randomly assigned to each of 3 groups: Group 1 (exercise only), Group 2 (joint mobilization combined with exercise), and Group 3 (rest-only control group). Three weekly interventions were given for 4 weeks (the control group rested for 4 weeks). The main outcome measures were goniometer, visual analogue scale (VAS), and Korean Kerlan Jobe shoulder-elbow (K-KJOC) scores. The ROM (external and internal rotation), pain intensity (at the moment of throwing), and functional performance were compared among the groups. RESULTS: No significant difference was observed among the groups in the range of external rotation of the shoulder before and after the intervention, but the range of internal rotation was significantly increased in Group 2 compared to Groups 1 and 3. Pain intensity was significantly lower in Group 2 than in Group 1 and 3, and functional performance was significantly increased in Group 2 compared to Group 1 and 3. CONCLUSION: An intervention that combined joint mobilization with exercise was more effective than resting or exercise alone for rapid recovery from sports injury and improvement in athletic performance.

Osteochondritis Dissecans of Elbow Joint (박리성 골연골염, 주관절)

  • Oh Jeong-Hwan;Choi Jin-Hyung;Park Jin-Young
    • Clinics in Shoulder and Elbow
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    • v.8 no.2
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    • pp.63-67
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    • 2005
  • Osteochondritis dissecans is a common cause of lateral elbow pain in throwing athletes and gymnasts between the age of 10 and 15 years. The pain frequently is insidious and progressive in nature and is relieved with rest in most cases. Compressive forces at the radiocapitellar joint along with a tenuous blood supply to the region may play a role in the etiology of this condition. Treatment is directed according to presenting symptoms, radiographic findings and status of the involved segment. Surgical management involves either an excision of a loose lesion and removal of loose bodies or reattachment of an osteochondral fragment. The role of subchondral penetration of debridement of the defect after fragment excision is unclear. Whether to excise and debride or to fix an unstale fragment is a highly controversial topic. The clinician should recognize osteochondritis dissecans of the elbow as a potentially disabling condition where the prognosis for return to sport is guarded

Determination of the Improvement Priority in a Small River Using GRID Analysis Technology of GSIS (GSIS의 그리드 분석 기법에 의한 소하천 정비 우선순위 결정)

  • 양인태;최영재;오명진
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.3
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    • pp.233-240
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    • 2000
  • A small rivers take advantage of not only a site of superb scenic beauty, a play space, a rest place but also a momentous waters reservoir, a drainage on territory residents. Likewise, part of the most massed a life space to a region dwellers shall be extremely in harmony with coexistence space in that every kind plant, animal over again a human being and so on. For improvement planning of small river, various way and model are presented. But, it's want of ability for small rivers of a adaption many-side and throwing in a lot of financial resources. Because the improvement planning of small river was designed all small river in a county, the priority must be preprocessed. Now, the counties prioritized for improvement planning of small river are a few, and acquisition and manipulation of the data are time-consuming. Geo-Spatial Information System (GSIS) is specifically designed to manage and analyze spatial data. It will be to offer the benefit to the determination of the improvement priority in a small river. The purpose of this study is to offer priority for improvement planning of small river using GSIS. For this purpose, it was developed using Arc/Info software and AML was used as a developing tool.

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The Study on The Origin, Changes, and Composition of Galgeulhaegi-tang (갈근해기탕(葛根解肌湯)의 기원(基源), 변천(變遷), 구성(構成)에 대한 고찰(考察))

  • Jang, Hyun-Su;Kim, Yun-Hee;Kang, Mi-Jeong;Lee, Ji-Won;Lee, Jun-Hee;Koh, Byung-Hee;Lee, Eui-Ju
    • Journal of Sasang Constitutional Medicine
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    • v.21 no.2
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    • pp.72-78
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    • 2009
  • 1. Objectives : This paper was written in order to understand the origin and changes of Galgeunhaegi-tang. 2. Methods : We analysis Galgeunhaegi-tang through pathology and new prescription in "Donguibogam(東醫寶鑑)", "Chobongwon(草本卷)", "Gabobon(甲午本)" and "Sinchukbon(辛丑本)" of "Dongyi Suse Bowon". 3. Results and Conclusions : We can find the first origin of Galgeunhaegi-tang in "Sinchukbon(辛丑本)" in "Donguibogam(東醫寶鑑)" which invelves Galgeunhaegi-tang in the categories of pestilence(瘟疫) and Yangmyeonggyeongbyeong(陽明經病). Also, we can find the origin in Jugoeng(朱肱)' Jojung-tang. Seungeumgalgeun-tang in the "Chobongwon(草本卷)" developed by a Galgeunhaegi-tang of "Gabobon(甲午本)", and Galgeunnabokja-tang in the "Chobongwon(草本卷)" developed by a Galgeunhaegi-tang of "Sinchukbon(辛丑本)". It is considered that Galgeunhaegi-tang of "Gabobon(甲午本)" solves heat depression(鬱熱), due to not throwing off, by using Galgeun(葛根) and Daehwang(大黃), and accompanied dryness(燥) by using Hangin(杏仁) and Sanjoin(酸棗仁) which moisten dryness(燥). It is considered that Galgeunhaegi-tang of "Sinchukbon(辛丑本)" solves heat depression(鬱熱) by using Galgeun(葛根) and accompanied dryness(燥) by using Gobon(藁本) which sets free dryness(燥).

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The Effect of PNF Stretching with Elastic Band on Ball Speed of High School Baseball Players (탄력밴드를 이용한 1회성 동체 PNF 스트레칭이 고등학교 야구선수의 피칭속도에 미치는 영향)

  • Lee, Sang-Won;Kim, Won-Hyun;Kim, Do-Youn
    • Journal of Digital Convergence
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    • v.14 no.12
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    • pp.525-535
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    • 2016
  • The purpose of this study was to evaluate the effect of thoracic dynamic stretching with elastic band on the ROM and ball speed for baseball player. For this purpose, 11 baseball players of the I city high school and university performed thoracic dynamic stretching with elastic band before throwing a ball. After stretching, we measured the ROM and ball speed and compared. The results were as follows. First, ROM after stretching showed a significant increase immediately compared with before stretching. Second, the speed of the ball was significantly increased after stretching compared with before. These results indicated that thoracic dynamic stretching with elastic band for baseball players might have a positive effect on ball speed as well as ROM.