• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.912-918
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• 2004

Main vibration problems of a transaxle type forklift truck are caused by the resonance of engine excitation force and natural mode shade of major components such as engine-mount system, mast, and main frame. But, it is well known that the reduction of vibration is very difficult because of the limitation of structural modifications. In this paper, the vibration characteristics of engine-mast system including engine mount were firstly identified by the experimental and simplified numerical methods. And also, the free and forced vibration characteristics of a whole forklift truck were surveyed with modal test and ODS(operation deflection shape) measurement. Based on these results, the reliable finite element model was developed. Finally, various countermeasures were considered and applied to a real forklift truck and then its effects were confirmed.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.129-135
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• 2019

Objective: The purpose of this study is to present the scientific and quantitative data by finding the common points and differences of the side-kick according to the height change through the difference of the side kick motion performance according to the three target height changes and the function of the lower limbs muscle in side kick motion of Taekwondo Poomsae. Method: For this, total 14 players were selected who were registered in Korea Taekwondo Association and skilled group 7 players who had a medal from national competition and 7 players who did not have Taekwondo experience from department of physics. 4 video cameras to the feature on side kick per target height, and the subjects' support foot was located on the ground reactor and the practice was conducted 3 times: waist, chest, and head as the target height. the basic materials were collected by using Kwon 3D XP program and the T-test was conducted to verify the statistic difference between groups (SPSS 24.0). At this time, the statistics significance level was set as .05 and the following conclusion was obtained. Results: The lower the proficiency and the higher the height, the more the joint coordination between the hip and the knee. Conclusion: Summary of the result shows a common point that the change of target's height makes the lower the proficiency and the higher the height, the more the joint coordination between the hip and the knee. Also, the higher the target's height became, the greater angular momentum of thighs, shanks, foot became in common.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.627-633
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• 1998

Achievements of Korean delegate students who attend on the 9th International Biology Olympiad(IBO) were compared with those of IBO participants for the 4th, 5th and 7th theoretical tests. It was predicted that four Korean delegates won medals in the 9th IBO on the basis of the average percentages of correct answer and the shifting patterns of achievement. And achievemens of four delegates during delegates training period were compared with that in the 9th IBO. Mean perecntages of theoretical part of them were 78.15%, 77.16%, 80.97% and 76.99% respectively, and total mean percentage was 78.32%. Their achievement was level for silver medalist. It was 86.56% on the average that they had achieved in the 9th IBO. This result was more than achievement in delegates training. Their percentages of achievement order were 90.84%, 97.71%, 82.44% and 70.99% respectively. One of them won gold medal and the others won silver medals. It was needed to develop effective teaching program for biology gifted-students and training preparing for IBO.