• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.345-353
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• 2012

Recently rapid urbanization facilitates development of high-rise building complex including apartment and office building in urban area. Many problems related with high-rise building are reported. Especially, unpleasant strong winds in pedestrian area are frequently encountered around the high-rise building. CFD simulation methods are used to analyze the wind environment of pedestrian level in high-rise building block. However the results show differences between CFD and measurement. The reason for the difference is that conventional CFD simulation couldn't consider the effect of trees, shrubs and plants which affect the wind environment. Canopy model is a solution to solve the limitation of CFD analysis. In this paper, the canopy model to predict wind environment of pedestrian level by CFD simulation will be proposed and the validity will be analyzed by comparison of measurement and CFD prediction.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.6
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• pp.687-693
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• 2011

Spring-mass models have been widely accepted to explain the basic dynamics of human gait. Researchers found that the leg stiffness increased with gait speed to increase energy efficiency. However, the difference of leg stiffness change with gait speed between the young and the elderly has not been verified yet. In this study, we calculated the lower limb stiffness of the elderly using walking model with an axial spring. Vertical stiffness was defined as the ratio of the vertical force change to the vertical displacement change. Seven young and eight elderly subjects participated to the test. The subjects walked on a 12 meter long, 1 meter wide walkway at four different gait speeds, ranging from their self-selected speed to maximum speed randomly. Kinetic and kinematic data were collected using three force plates and motion capture cameras, respectively. The vertical stiffness of the two groups increased as a function of walking speed. Maximum walking speed of the elderly was slower than that of the young, yet the walking speed correlated well with the optimal stiffness that maximizes propulsion energy in both groups. The results may imply that human may use apparent limb stiffness to optimize energy based on spring-like leg mechanics.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.226-232
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• 2009

In this study, treadmill walking and overground walking were compared at the same condition based on kinematics and energy expenditures(EE). In addition, we compared the actual energy expenditure and calculated EE by treadmill. The kinematics of treadmill and overground walking were very similar. The values at each joint were significantly different(P<0.05), but magnitude of the difference was generally less than 4$^{\circ}$. In the EE using cardiopulmonary exercise, EE of treadmill walking was significantly greater when measured on the overground. It seemed to be the increased stress during the gait by the continuous movement of the belt. As the velocity increased, there was significant difference between actual EE and calculated EE by treadmill due to EE curve increasing exponentially. Therefore the further study would be required to find the correlation of the two methods and calibrate the values from them.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.3 s.246
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• pp.241-248
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• 2006

Shoe cushioning systems are important to prevent body injuries. This study developed and evaluated a cushioning system to reduce impact force on the heel. The cushioning system suggested consist of a polyurethane pocket, which contains water and porous grains of open cell to dissipate the energy effectively. Load-displacement curves fer the shoe cushioning system were obtained from an instrumented testing machine and the results were compared with various pockets with air, water or grains. Mechanical testings showed that the pocket with 5g porous grain was the best for the cushioning system. This system can be applied to the design of various kind of sport shoes.

• Transactions of The Korea Fluid Power Systems Society
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• v.2 no.2
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• pp.14-20
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• 2005

This study developed and evaluated a shoe cushioning system to reduce impact force patterns during running. The shoe cushioning system is composed with a poly urethane pocket, which contains water and porous grains to absorb the force against the weight inside the pocket. Load-displacement curves for the shoe cushioning system were obtained from an instrumented testing machine and the results were compared with various pockets that have air, water or grains. Mechanical testings showed that the pocket with 5 g particles was the best for the shoe cushioning system. This founding will be helpful to designing the shoe.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.237-240
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• 2023

본 논문은 철도 건널목(교차로)에서 발생하는 차량, 보행자 및 야생 동물 사고 등의 상황에서 발생하는 위험 요소를 설정하고 철도 건널목(교차로)의 운행상황을 확인할 수 있도록 모형 철도 주변에 유형별 센서들을 설치하고 데이터를 인지하여 시스템에 저장하고, 유효한 데이터 분석을 통해 Orange3 머신러닝 기법을 적용한다. 철도 건널목에 관련된 이미지 중 위험인자로서 차량, 보행자 및 야생동물등의 객체를 감지하고 데이터를 수집하여 활용한다. 또한 이러한 데이터들은 이용자 상황에 맞는 철도 데이터 운영 시스템으로 적용할 수 있도록 위험 예측 시스템을 제안한다.

• The Journal of the Korean life insurance medical association
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• v.26
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• pp.3-12
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• 2007

Frailty는 노인에서 장애와 사망의 주된 원인이 되는데 근육 감소증, 근력 약화, 에너지/화동력/보행속도의 감소, 염증성 싸이토카인의 증가를 특징으로 한다. 비타민 D의 결핍 또는 저항증은 근육기능과 단백질 합성에 대한 효과, 염증성 싸이토카인의 표현 조절, 혈관계에 대한 영향, 중추신경계에 대한 영향을 통해 Fraity syndrome에 대한 원인인자가 될 수 있다. 따라서 만약 비타민 D 결핍이 이 증후군의 중요한 요인이라면 비타민 D 투여는 안전하고도 비용-효과적인 Frailty syndrome에 대한 예방 및 치료 방법이 될 수 있는 것이다.

• Proceedings of the KSCN Conference
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• 2004.12a
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• pp.120-120
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• 2004

• Proceedings of the KSCN Conference
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• 2006.05a
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• pp.79-79
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• 2006

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.309-312
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• 2003

Though a legged robot has high terrain adaptability as compared with a wheeled vehicle, its moving speed is considerably low in general. For attaining a high moving speed with a legged robot, a dynamically stable walking, such as running for a biped robot and a trot gait or a bound gait for a quadruped robot, is a promising solution. However, energy efficiency of a dynamically stable walking is generally lower than the efficiency of a stable gait such as a crawl gait. In this paper, we present an experimental study on the energy efficiency of a quadruped walking vehicle. Energy consumption of two walking patterns for a trot gait is investigated though experiments using a TITAN-VIII.