• Korean Journal of Applied Biomechanics
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• v.32 no.2
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• pp.43-48
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• 2022

Objective: The purpose of this study was to verify the effectiveness among simulating ski jumping trainings by comparing with actual ski jump. Method: Three healthy youth national athletes were recruited for this study (age: 13.70 ± 0.9 yrs, height: 169.30 ± 0.9 cm, jumping caree: 5.3 ± 0.9 yrs). Participants were asked to performed ski jumping with 3 simulating and one actual situation. A 3-dimensional motion analysis with 5 channels of EMG was performed in this study. Muscle activations of Rectus Femoris [RF], Tibialis Anterior [TA], Thoracis [TH], Gluteus maximus [GM], and Gastronemius [GL] were achieved with sampling rate of 2,000 Hz during each jump. Results: In the case of S1 in the actual jumping motion, the deviation of the muscle activity peak did not appear each trial, and the jump timing was consistent. For S2, the timing of the muscles peak activation which can maintain the posture of the upper body and ankles appeared at the beginning. In the case of S3, the part maintaining the ankle posture at the beginning appeared, but it could be expected that it would progress in the vertical direction due to the activation of GL at the time of jumping. Conclusion: The muscle activation peak before the take-off point showed a different pattern for each athlete, and individual differences were large. In addition, it was attempted to confirm the actual jump with simulation jump, and it was found that not only the difference in patterns but also the fluctuations in the timing of each muscle activation peak were large.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.137-143
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• 2011

In this paper, we implement the ski jump visualization tool using the OpenGL graphics library. Among the evaluation elements of jump, the distance of jump is most important. Also, the distance of jump depends on Lift-to-Drag Ratio. In the previous studies, the visualization too according to the consequential changing of variety factors is insufficient. This study provides an easy style flying posture visualization tool to the user who using Lift-to-Drag Ratio. Furthermore, there is to implement an international standard jumping hill by virtue of entered five main data. The results of this study can be applied with reference data for better ski jump.

• Steel and Composite Structures
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• v.3 no.2
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• pp.141-152
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• 2003

The ski jump in Innsbruck known for the famous annual New Year "Four-ski-jump-tournament" has been fully renewed. The original jumping tower (built for the 1976 Olympic winter games) was fully pulled down and a new landmark similar to a lighthouse has been erected located on a small hill at the border of the city. Zaha Hadid(London) won the international architectural competition for this significant building. The constructional realisation has been ordered from Aste Konstruktion and has been finally honoured with the Austrian state award for consulting 2002. After a very strict timetable the building was already handed restaurant at the top.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.193-200
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• 2012

A numerical analysis is carried out in order to obtain aerodynamic data of the ski jump. The body modelling of Korean people is used in the numerical simulation and the result is validated by comparing it with the wind tunnel experiment. A flying posture, which provides the maximum lift-to-drag ratio, is found by analyzing the aerodynamic coefficients of various flight conditions. The result of the present study can be applied to fixing the postures of Korean ski players and is expected to advance the national sports science.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.113-118
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• 2005

Small form factor optical disks for near-field optics using solid immersion lens were developed. Disk durability properties in terms of head-disk interface (HDI) properties were investigated by drag test, diamond like carbon film and lubricant film were coated on the small form factor disk to enhance HDI. Disks with glass substrates and lubricant films after heat treatment showed more durable characteristics. Coverlayers made of UV resin were uniformly coated by spin coating In which the ski-jump could not be formed by adopting outer ring technique.

• Transactions of the Society of Information Storage Systems
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• v.2 no.1
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• pp.26-31
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• 2006

Small form factor optical disks for near-field optics using solid immersion lens were developed. Diamond like carbon film and lubricant film were coated on the small form factor optical disk to enhance the head-disk interface(HDI) characteristics. The disk durability properties in terms of HDI phenomena were investigated by drag test. Disks with glass substrates and the lubricant films experienced heat treatment showed more durable characteristics. Coverlayers made of UV resin were uniformly coated by spin coating in which the ski-jump could be removed by adopting outer ring technique

• Transactions of the Society of Information Storage Systems
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• v.1 no.2
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• pp.188-191
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• 2005

Two different coverlayers which is useful for an optical buffer and a mechanical protection made of not only UV resin but also polycarbonate coversheet were prepared on small form factor optical disks. Thin coverlayer of 10 ${\mu}m$ and thick coverlayer of 80 ${\mu}m$ were fabricated. 10 ${\mu}m$-thick coverlayer was coated using UV resin material by spin coating method for the flying optical head application. On the other hand, 80 ${\mu}m$-thick coverlayer using coversheet with the resin bonding material was prepared for the non-flying optical head application. Both cases, the thickness uniformity seem to be the primary prerequisite factor, and it was analyzed. Thickness of 10 ${\mu}m$-thick UV resin coverlayer could be controlled within ${\pm}0.2m$ range and 80 ${\mu}m$-thick coversheet could be controlled within ${\pm}3{\mu}m$ range. However, the yield of such thickness tolerance was not good. New design of metal housing holder and polycarbonate outer ring was adopted to diminish the ski-jump phenomenon. Specifically, the polycarbonate outer ring was very effective to reduce the ski-jump. However, it should be careful to maintain uniform edge between disk and ring for the perfect coverlayer.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.183-184
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• 2011

본 논문에서는 양항비를 이용하여 스키점프 시각화 도구를 구현하였다. 스키점프는 점프대에서 도약시의 가속도와 맞바람을 통한 양력을 이용하여 활공하는 스포츠이다. 다양한 영향 요소 중에서도 점프의 거리가 가장 중요한데 이는 받음각에 따른 양력과 항력의 비인 양항비에 의해 결정된다. 기존 연구에서 최적의 양항비를 계산하여 이미 표준적인 받음각과 스키의 벌림각, 구부린 각 등은 잘 알려져 있다. 그러나 이러한 영향 인자의 변화에 따른 시각화 도구는 미흡한 실정이다. 본 논문에서는 양항비를 이용하여 사용자에게 직관적인 자세 시각화 도구를 제공한다. 구현을 위하여 OpenGL을 이용하여 그래픽을 표현하고 기존의 수학적 모델을 이용하여 사용자가 요구하는 인자의 변화에 따른 자세변화를 보인다. 본 논문의 결과물은 더 나은 스키점프을 위한 참고자료로 활용될 수 있을 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.628-629
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• 2005

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.183-184
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• 2015

본 논문에서는 HTML5 기반의 대화형 스키점프 시각화 도구를 소개한다. 스키점프의 비거리는 다양한 요소에 영향을 받지만 받음각에 따른 양력과 항력의 비인 양항비에 의해 크게 결정된다. 본 논문에서는 스키의 벌림각, 구부린 각 등을 면적 계수로 두고 물리적인 2차원 좌표를 계산하여 시각화한다. 사용자의 상호작용성을 위하여 각 계수나 영향 요소를 조정할 수 있게 하여 실시간으로 스키점퍼의 자세와 비거리를 확인할 수 있게 하였다. 또한 구현 결과는 웹기반에서 동작하여 사용자의 접근성과 모델 변경에 따른 용이성을 제공한다. 본 논문의 결과물은 스키점프 경기력 향상을 위한 분석 도구로 활용될 수 있을 것이다.