• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.89-97
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• 2008

The purpose of this study was to analyze the foot-pressure distribution of Tennis Shoes for assessing their functionality. 10 university male students (shoe size: 265mm) who had no history of injury in the lower extremity and a normal gait pattern participated in this study. Four types of tennis shoes, most popular in Korea (A, B, C & D company), were selected and tested. Using the PEDAR-X system and PEDAR-X insoles, 4 different motion stages were analyzed for the foot-pressure distribution: (a) straight running; (b) c-cut($45^{\circ}$ left turn running; (c) forehand stroke; and (d) backhand stroke. Results revealed that in all stages, there were no statistically significant differences among the types of shoes; however, descriptive statistics indicated that functionality of shoe types was somewhat different depending on the type of stages. The order in functionality found was C>A>B>D.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.361-380
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• 2002

The purposes of this study were to a analysis of friction relation between tennis outsole and tennis playing surfaces. Tennis footwear is an important component of tennis game equipment. It can support or damage players performance and comfort. Most importantly athletic shoes protect the foot preventing abrasions and injuries. Footwear stability in court sports like tennis is incredibly important since it is estimated that as many as 45% of all lower extremity injuries occur in the foot and ankle. The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it. The friction force opposes the motion of the object. Friction results when two surfaces are pressed together closely, causing attractive intermolecular forces between the molecules of the two different surfaces. The outsole provides traction and reduces wear on the midsole. Today's outsoles address sport specific movements (running versus pivoting) and playing surface types. Different areas of the outsole are designed for the distinct frictional needs of specific movements. Traction created by the friction between the outsole and the surface allows the shoe to grip the surface. As surfaces, conditions and player motion change, traction may need to vary. An athletic shoe needs to grip well when running but not when pivoting. Laboratory tests have demonstrated force reductions compared to impact on concrete. There is a correlation between pain, injury and surface hardness. These are a variety of traction patterns on the soles of athletic shoes. Traction like any other shoe characteristic must be commensurate and balanced with the sport. The equal and opposite force does not necessarily travel back up your leg. The surface itself absorbs a portion of the force converting it to other forms of energy. Subsequently, tennis court surfaces are rated not only for pace but also for the percentage of force reduction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.633-634
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• 2009

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.73-76
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• 2006

테니스 경기 영상에서 테니스 코트 영역과 선수의 위치를 추적하기 위한 알고리즘을 제안한다. 공의 움직임을 찾기 위해서는 코트와 선수의 위치를 파악해야 하므로 이진화 영상과 형태론적 해석을 통하여 테니스 코트 영역과 선수 영역을 인식하도록 한다. 선수의 위치가 확인되면 공의 움직임이 예측되는 장소를 찾아 공이 지나가는 정보가 제공될 경우 공의 위치를 인식하고 칼만 필터를 이용하여 공의 움직임을 추정하고 공의 위치를 추적한다. 공의 움직임 정보를 이용하여 고속 이동에 의한 이미지의 손실을 개선하는 알고리즘을 제안한다.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.607-612
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• 1986

최근 테니스의 저변인구가 크게 증가함에 따라 테니스 라켓의 제작기술도 상당한 수준에 이르렀고 설계제작의 자동화에 의해서 양질의 제품이 시판되고 있다. 그러나 라켓에 볼이 임팩트될때 생기는 진동으로 야기되는 테니스 엘보우 등, 해결해야 할 문제들이 아직도 남아 있다. 이와같이 테니스 라켓의 정적인 강도 뿐만아니라 동적인 특성도 중요한 관심의 대상이 되어감에 따라 볼 컨트롤을 용이하게 한다거나, 안정타점영역(Sweet Spot)의 확장과 그립부의 진동등에 의해서 발생하는 엘보우 현상을 방지하기 위해 여러가지 연구가 수행되어 왔다. 특히, 다차원 스펙트럼해석 및 모우드 해석법에의해 그립부에 미치는 진동원의 동정과 라켓의 동적거동에 대해서 연구되었고, 라켓의 재질변경과 그립부의 구조변경에 의한 안정타점영역에 영향을 미치는 모우드 파라미터(Modal Parameter)의 추정에 관한 연구도 수행되었다. 이러한 연구들은 결국 안정타점영역을 확장시키거나 테니스 엘보우를 방지하기 위한 것으로서 이러한 목적을 달성하기위해 테니스 라켓의 진동 모우드에 관계되는 파라미터들을 찾아서 그 모우드 파라미터의 변화에 따르느 진동 모우드의 거동에 대해서 연구할 필요가 있다. 본 논문에서는 실험적인 모우드 해석법을 실제 테니스 라켓에 적용하여 모우드 파라미터들을 구한 다음 그 파라미터의 변화에 따르는 안정타점영역의 변화를 컴퓨터 시뮬레이션을 통해서 예측하였다. 또한 안정타점영역을 넓히고 라켓의 동특성을 개선시킬 수 있는 모우드 파라미터를 찾아서 테니스 라켓의 설계, 제작 단계에 정보를 제공하는 CAD(Computer Aided Design)에 좋은 자료를 얻고자 한다. 있으나 파도에 의한 영향이 가장 크므로 본 논문에서는 파도에 의한 영향만을 고려하였다. 파도는 쌍동선에 외란으로 작용하며 측정할 수 없는 양이므로 PID, LQ 제어에서는 제어모델에 포함되지 않지만 LQG 제어에서는 제어모델에 포함된다. LQG 제어의 경우 제어모델에 파도를 백색잡음으로 가정하고 제어기를 구성한 것 (LQG1)과 2차의 쉐이핑필터(shaping filter)를 사용하여 구성한 것(LQG2)으로 나누었다.져 한다.) 식도 이물에 의한, 또는 식도경술에 의한 합병증이 초래한 경우는 식도점막열상 1례 (1.8 %), 식도 천공 1례 (1.8 %) 였으며, 기도이물에 의한, 또는 기관지경술에 의한 합병증이 초래한 경우는 무기폐 2례 (11.1 %), 폐렴 3례 (16.7 %)로 나타났다.5예에서 소실되었다. 5 ) 청각심리검사 (Psychoacoustic evaluation)에서 폴립은 술전에 Grade 1∼2의 사성이 있었던 11예중 술후 10예에서 Grade 0로 되었으며 Grade 1∼2의 사성이 있었던 3예의 결절에서도 모두 Grade 0로 정상화되었다.>치를 측정한 결과 투여전과 차이가 없었다. 7) 이상의 결과로 볼때 Cis-platinum 사용으로 인한 이중독증은 신장기능이 정상일때는 충분한 hydration으로써 예방이 가능하며 동시에 금기로 알려져왔던 감음성난청이 있는 두경부악성종양환자에서도 세심한 주의하에 적절히 사용한다면 좋은 결과를 얻을 수 있을 것으로 사려된다.은 결과를 얻었기에 문헌고찰과 함께 보고하는 바이다. 1) 이관폐쇄술후 18시간에 최초로 삼출액이 확인되었으며 그 이후는 전실험군에서 삼출성중이염이 유발되다. 2

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.1
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• pp.95-105
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• 1988

The dynamic characteristics of a tennis racket were identified by experimental modal analysis and the sweet spot due to these was calculated. A tennis racket was selected as a model reference and modal parameters of the racket were estimated from the transfer function measured by experiment. The transfer function was reconstructed by the modified modal parameters on the assumption that the racket was locally modified, for example, a change in the material of the frame and the attachment of a damping material to the grip. The change of the dynamic characteristics, especially natural frequency and magnitude of the second and the third vibrational modes, were evaluated from the reconstructed transfer function. The change of the sweet spot due to the modified modal parameters was estimated and visualized through computer graphic simulation by the criterion of the sweet spot measured before structural modification. The modal parameters for improvement of the dynamic characteristics.

• Science of Emotion and Sensibility
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• v.11 no.1
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• pp.91-104
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• 2008

This study searches for an abstract aesthetic dimension that has an important response to preference by finding products excluded in past studies on aesthetics. Furthermore, the adjective image languages are examined, grouped and examined in order to also take into account the dimensions that are regarded as important for the selected product. Based on this, the preference trends will be inferred and the level of aesthetic dimensions that are import in the product will be found and presented based on its preference to create an accurate objective point. Based on the values of the levels of the aesthetic preference types and aesthetic elements found by this and presenting the preferred types in the design process, the objective of this study is to create designs with small chance of failure. In addition, it attempts to present a new direction for research of aesthetic dimensions.

• Elastomers and Composites
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• v.21 no.4
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• pp.309-322
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• 1986

This survey reports on the extensive examination of the qualify of 14 jogging and tennis shoes separately, availavable in the domestic market, Both jogging and tennis shoes were catagorised in two groups, namely the general goods(less expensive ones) and the exclusive goods(expensive models). The detailed classification are shown below; The domestic products meet the general purpose just as that of the foreign products. Due to the adhesion technology, the domestic tennis shoes consist of rubber sole with natural leather upper;In fact, the desirable combination, as foreign products, must be polyurethane/natural leather. The expensive models were heavier than the less expensive ones. The greater weight difference of right and left shoes are shown in the expensive models than that of the less expensive ones. The moisture absorption ratio of the expensive model is far superior in comparison with the less expensive model. The reason is identified by the material supplyed to produce the expensive model consisted of the natural leather and proper parts. The abrasion resistance of the expensive models were excellent that of the less expensive ones, because the rubber soles were showed the properties better than polyurethane sole which was used in the less expensive model.

• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1331-1343
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• 2009

In this paper, we are interested in tennis games and the best of all matches that is fair to most of all participants. Especially when players are ordered in accordance with their playing ability, we are interested in finding the best of all matches that is even with each other's playing pair. We propose a loss function And using our proposed loss function, we get a best match that obtains the minimal loss according to the number of games for given participants.

• Clinics in Shoulder and Elbow
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• v.7 no.1
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• pp.35-40
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• 2004

Purpose: The aim of this study was to investigate effects of calcific lesion on shockwave therapy of the tennis elbow. Materials and Methods: twenty-four patients with refractory tennis elbow were treated with shock waves. The patients were evaluated by assessment of pain using visual analog scale (VAS) and simple elbow test (SET). Comparision of clinical outcomes for the patients with and without calcification in the extensor tendon and/or cortical irregularity of lateral condyle was tried to determine if this could be a possible prognostic factor in clinical settings. Overall clinical outcomes were evaluated by Roles and Maudsley score at 12 months after ESWT. Results: Significant improvement of symptoms were observed in 20 (83 %) patients at 12 months follow up according to Roles and Maudesley scores. The patients with calcification and/or cortical irregularity improved significantly better, when compared to the patients without calcification and/or cortical irregularity at follow up. Conclusion: This study suggests that shock waves therapy could be considered as effective and noninvasive treatment modality for refractory tennis elbow. Also calcific deposit in extensor tendon and/or cortical irregularity of the lateral epicondyle was seem to be good prognostic factor for shock wave therapy for tennis elbow