• Title/Summary/Keyword: Feet Velocity

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A Workspace Analysis Method of Multi-Legged Walking Robot in the Velocity Domain (다족 보행로봇의 속도작업공간 해석)

  • 이지홍;전봉환
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.6
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    • pp.477-483
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    • 2002
  • This paper deals with a workspace analysis of multi-legged walking robots in velocity domain(velocity workspace analysis). Noting that when robots are holding the same object in multiple cooperating robotic arm system the kinematic structure of the system is basically the same with that of a multi-legged walking robot standing on the ground, we invented a way ot applying the technique for multiple arm system to multi-legged walking robot. An important definition of reaction velocity is made and the bounds of velocities achievable by the moving body with multi-legs is derived from the given bounds on the capabilities of actuators of each legs through Jacobian matrix for given robot configuration. After some assumption of hard-foot-condition is adopted as a contact model between feet of robot and the ground, visualization process for the velocity workspace is proposed. Also, a series of application examples will be presented including continuous walking gaits as well as several different stationary posture of legged walking robots, which validate the usefulness of the proposed technique.

Development of 30 Feet Sailing Yacht and Performance Predictions (30피트급 요트의 선형개발 및 성능추정)

  • Yoo, Jae-Hoon;Van, Suak-Ho;Ahn, Hae-Seong;Kim, Jin;Kim, Sang-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.1 s.139
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    • pp.34-42
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    • 2005
  • An overview of 30 feet sailing yacht design is presented, with an emphasis on the factors contributing to start-up popularization. After prescribing the configurations of the purposed yacht, the design of the hull form with a rudder and a keel, are schematically described. Also the determinations of the dimensions of the sail and rig are performed. Finally this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity prediction program (VPP). The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

Height perception of large airplane pilots during landing flare (대형 비행기 조종사의 착륙 조작 시의 높이지각)

  • Kim, Yong-Seok;Sohn, Young-Woo;Park, Soo-Ae;Kim, Chil-Young
    • Science of Emotion and Sensibility
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    • v.10 no.4
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    • pp.539-554
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    • 2007
  • Pilots of large airplanes have to land their airplanes with insufficient visual information because of high approach speed, high vertical velocity and high location or altitude of the cockpits from the runway intending to touch down. This study verifies that, due to the insufficient information, large airplane pilots can't exactly perceive height of their airplanes during the flare. Study 1 explored whether it's possible for the pilots to accurately perceive height with the static visual cues only. We showed them pictures of the runway taken from the pilot's pionts of view and asked them to assess the height of the airplanes. They determined exact height of the airplanes at the height of 85 feet, but they could not, at lower than 55 feet which is the flare preparation altitude. Study 2 explored whether it's possible for the pilots to accurately perceive height when dynamic cues were added to the static visual cues. We showed them videos of the runway taken from the pilot's pionts of view. With more cues they determined exact height of the airplanes at the height of 50 feet, but they could not, at the altitude of lower than 30 feet which is the flare altitude. As experience is believed to be a major factor which affects interpretation of the visual cues, we compared the accuracy of the assessment of the experienced captions and that of the in-experienced first officers. We found there was no significant difference between them.

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A study on the comfort thermal environment by the Draft in floor panel heating system (바닥면복사난방에서 Draft에 의한 쾌적열환경에 관한 연구)

  • KyungHeeLee
    • Journal of the Korean housing association
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    • v.7 no.2
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    • pp.121-129
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    • 1996
  • This study was to estimate how about various effects on the body thermal sensation as air velocity. clo. mean radiant temperature and resultant temperature are varied. The indoor thermal environment elements are measured under the five different of air velocity. Using the above considerations. the following results are obtained. ▶ The states, the air velocity under 0.5 m/s and 0.63 to 0.9 clo. were shown that the comfort zone of mean radiant temperature by 21.2~24.7C, the neutral point by 22.8C, the resultant temperature by 20.7-24.4C and the neutral point by 22.6C. ▶ On equal condition, the draft was occurred at a given air-velocity under 0.5m.s. It was also appeared the floor panel heating system affecting the body thermal sensation by the subject’s below-chest parts and the local discomfort by sensations on the feet and the knees.

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Experimental Study on the Hydrodynamic Forces of 30 Feet Sailing Yacht (30피트급 요트의 유체력에 대한 실험적 연구)

  • Yoo, Jae-Hoon;Ahn, Hae-Seong
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.3
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    • pp.233-240
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    • 2005
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree, which was expected in the initial design stage. It is thought to be the useful informations that the keel has au effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition.

NUMERICAL METHOD FOR VELOCITY PREDICTION CONSIDERING MOTION OF A YACHT (풍상 범주 중인 세일링 요트의 자세를 고려한 속도 추정 방법)

  • Park, M.Y.;Lee, H.;Park, S.;Rhee, S.H.
    • Journal of computational fluids engineering
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    • v.19 no.3
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    • pp.1-7
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    • 2014
  • One of the most important factors in sailing yacht design is an accurate velocity prediction. Velocity prediction programs (VPPs) are widely used to predict velocity of sailing yachts. VPPs, which are primarily based on experimental data and experience of long years, suffer limitations applied in realistic conditions. Thus, in the present study, a high fidelity velocity prediction method using the computational fluid dynamics (CFD) is proposed. Using the developed method, velocity and motion of a 30 feet sloop yacht, which was developed by Korea Research Institute of Ship and Ocean (KRISO) and termed KORDY30, were predicted in upwind sailing condition.

Structrual Dynamic Analysis of a Diving Springboard to Reach Settled Height - Using Co-rotational Formulation (다이버가 일정한 높이로 도약 시 CR기법을 이용한 스프링보드의 구조 동역학적 해석)

  • Lee, Ji-Woo;Lee, Sang-Yeob;Lee, Sang-Hyeon
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.217-221
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    • 2016
  • In this paper, a springboard for diving is analysed to find out how much force a diver should apply to reach specific height when the diver jumps. The springboard is presumed to Co-rotational plane cantilever beam(CR-beam), so EDISON program related to Co-rotational framework is used. The force of the person is supposed to sine function and the demanded height is fixed. Same velocity makes same height regardless of diver's weight. So, the velocity of springboard when the feet of a diver are separated from the springboard is a main factor of the analysis. The result shows that there is no association between deformation and weight and also between velocity and weight. That is, the required force to reach a optimal height is fixed whatever the diver's weight is.

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Performance Predictions for Sailing Yacht by Towing Tests and VPP Calculation (예인수조 시험 및 VPP 계산에 의한 세일링 요트의 성능 추정)

  • Yoo Jae-Hoon;Ahn Hae-Seong
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.1
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    • pp.116-124
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    • 2006
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree. which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity Prediction program (VPP) The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

Performance Predictions for Sailing Yacht (세일링 요트의 성능 추정에 관한 연구)

  • Yoo, Jae-Hoon;Ahn, Hae-Seong
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.824-831
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    • 2005
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree, which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity prediction program (VPP). The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

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The Effects of Augmented Low-dye Taping on One Leg Standing Balance in People with Flat Feet (평발에 적용한 아규먼트 로우-다이 테이핑이 한 발 서기 균형에 미치는 영향)

  • Hwang, Yoon-Seong;Lee, Jeong-Mok;Kang, Ho-Jeong;Park, Ji-Seong;Park, Hae-Sol;Woo, Young-Keun
    • PNF and Movement
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    • v.17 no.2
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    • pp.215-222
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    • 2019
  • Purpose: The objective of this study was to investigate whether augmented low-dye taping treatment, which consists of low-dye, reverse-six, and calcaneal-sling taping, is effective in alleviating the collapse of the medial longitudinal arch, which is used for physical balancing during one leg standing. Methods: The subjects comprised 27 students in their 20s whose navicular bone height was lowered by 10 mm or more when evaluated using the navicular drop test. Those with interference factors like deformities, fractures, or traumas were excluded. Frequency-division multiplexing was used to measure one leg standing, and the method to avoir the average each time after 3 times of measurement was applied. Results: Significant differences in the center of pressure (COP) path length, COP average velocity, and forefoot force were observed during left leg standing (p<0.05), but for right leg standing, only changes in forefoot force were noted. Conclusion: Based on the changes to the non-dominant leg in terms of COP path length, COP average velocity, and forefoot force, the immediate effect of augmented low-dye taping, which combines three types of anti-pronation taping, on one leg standing balance in people with flat feet was confirmed.