• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.743-747
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• 2000

The coordinated mechanism of terrestrial vertebrates enables them to maneuver over all of the terrain conditions since they have a distinct ability to adapt to varying conditions. Their locomotions remain infinitely more advanced and elegant than that of present-day existing mechanical walking robots. However, the principles of existing walking robots are based more on technical rather than on biological concepts, yielding unstable locomotion with low speed. In order to apply these advanced biological phenomena to the mechanical design of 4-legged walking robot, modeling methods are introduced and mathematical equations are also introduced.

• Journal of the Korean Society of Costume
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• v.36
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• pp.205-217
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• 1998

Several aspects of conscious about somato-type were analysed for high school girls among Seoul, Kwangju, Wando. Questionnares was comprised of 24 item of the conscious about somatotype. Questionnaress were sent to sample of students of high school. The data from 593 respondantss were analysed in using Freequency, Crosstab, and T-test. The results were as follows: 1. High school students in Wando tend to have shorter and fatter than Seoul and Kwangju. 2. Respon-dents were conscioused of , , . 3. Of the trouble of somatotype, respondents of all region have troubled about , , , , It was founded that Respon-dents in Seoul have much the trouble about , than other regions. 4. Mean of Agreement of somatotype were scored 3.49 in Seoul 3.37 in Kwangju, 3.39 in Wando. It was founded that respondents in Seoul were not satisfied more than Kwangju, Wando. And then Respondents in Seoul have strong aspiration to be slim about somatotype although they are a stansard somatotype.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.429-433
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• 2016

Moving robot is divided 2 kinds; one is the robot using wheels and the other has leg structure. On plat terrain, the former is better than the latter because it has fast speed and simple method to control. But on non-plat terrain, the situation is reversed. The robot using legs has slow speed but it has advantage to adjust various environments. This robot is expected to contribute to human in many fields such as rescue and exploration and so on. So walking robot is worth enough to research. In this paper, we present the design of 4-legged walking robot based on Jansen mechanism using m-Sketch and Edison Designer.

• The Journal of Korea Robotics Society
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• v.14 no.3
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• pp.196-202
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• 2019

Snake robots are slower than wheeled robots or legged robots, while they have an excellent terrainability in a disastrous area. Considering their advantages and disadvantages, a legged robot whose legs are snake robots, 'Quadnake' was proposed in this research. Five motions of the snake were analyzed. Applying these motions, Quadnake could implement eight kinds of motions which snake robots and quadruped walking robots can implement. As a result of it, Quadnake can have the advantages of both a snake robot and a walking robot. It is expected to move stably in a harsh terrain with snake's motion and move fast with walking.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.448-453
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• 2012

There are many researches to develop robots that improve its mobility to adapt in various uneven environments. In the paper, a hybrid wheeled and legged mobile robot is designed and a obstacle avoidance algorithm is proposed based on low power walking using LRF(Laser Range Finder). In order to stabilize the robot's motion and reduce energy consumption, we implement a low-power walking algorithm through comparison of the current value of each motors and correction of posture balance. A low-power obstacle avoidance algorithm is proposed by using LRF sensor. We improve walking stability by distributing power consumption and reduce energy consumption by selecting a shortest navigation path of the robot. The proposed methods are verified through walking and navigation experiments with the developed hybrid robot.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.217-230
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• 2002

본 연구는 민감도 분석을 통한 다지교차로의 효용성 분석 연구로 신호교차로, Roundabout, 그리고 Modern Roundabout의 특성을 고찰하고 교통류의 특성에 따른 민감도 분석을 통한 교차로 형태를 검토하는 것에 그 목적을 두고 있다. 이를 위해, 첫째, 신호교차로와 Roundabout의 특성과 사례를 고찰하였다. 둘째, 4지교차로와 5지교차로의 교통류 특성별로 교통량을 산정하여, TSIS Tool을 이용한 분석을 통해 교통류 특성별 신호 교차로와 Round about의 민감도를 비교하였다. 셋째, 민감도 비교를 통한 교통류 특성별 효율적인 교차로 형태를 도출하였다. 4지교차로의 경우, 첫째, 일반적으로 V/C비의 변화에 대해 V/C비가 0.7이하일 때는 Roundabout가 V/C비가 0.7을 초과할 때는 신호교차로가 효율적인 것으로 나타났다. 둘째, V/C비별 회전교통량의 변화와 회전교통량 변화별 V/C비 변화에서도 V/C비의 변화의 분석결과와 비슷한 양상을 보였다. 5지교차로의 경우, 첫째, 4지교차로와는 달리 전반적으로 신호교차로 보다는 Roundabout가 더 효율적인 교차로 형태로 나타났다. 둘째, V/C비별 회전교통량의 변화와 회전교통량 변화별 V/C비 변화에서는 V/C비가 0.8을 초과하고 우회전교통량비가 30%∼40%인 경우에 신호교차로가 조금 더 효율적인 것으로 나타났다.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.153-162
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• 2008

This study deals with the traffic accidents at the 4-legged signalized intersections in Cheong-ju. The purpose is to comparatively analyze the characteristics and models by the accident type using the data of 143 intersections. In pursuing the above, this study gives particular emphasis to modeling such the accidents as head on collision, rear end collision, side swipe, side right angle collision, and others. The main results are the followings. First, the overdispersion tests show that the negative binomial regression models are appropriate to the traffic accident data in the above contexts. Second, five accident models are developed, which are all analyzed to be statistically significant. Finally, the models are comparatively evaluated using the common variable(ADT) and type-specific variables.

• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.438-446
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• 2022

In this paper, we propose an intelligent three-legged landing system that can maintain stability and level even on rough terrain than conventional four-legged landing systems. Conventional landing gear has the limitation that it requires flat terrain for landing. The 3-leg landing system proposed in this paper extends the usable range of the legs and reduces the weight, allowing the quadcopter to operate in various environments. To do this, kinematics determine the joint angles and coordinates of the legs of the two-link structure. Based on the angle value of the quadcopter detected via the IMU sensor, the leg control method that corrects the posture is determined. A force sensor attached to the end of the leg is used to detect contact with the ground. At the moment of contact with the ground, landing control starts according to the value of the IMU sensor. The proposed system verifies its reliability in various environments through an indoor landing test stand. Finally, in an outdoor environment, the quadcopter lands on a 20 degree incline and 20 cm rough terrain after flight. This demonstrates the stability and effectiveness of the 3-leg landing system even on rough terrain compared to the 4-leg landing system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.209-210
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• 2012

• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.143-149
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• 2018

Objective: This study aimed to investigate the influence of landing foot orientations on biomechanics of knee joint in order to identify vulnerable positions to non-contact knee injuries during single-legged landing. Method: Seventeen men (age: $20.5{\pm}1.1 years$, height: $175.2{\pm}6.4cm$, weight: $68.8{\pm}5.8kg$) performed single-leg drop landings repeatedly with three different landing foot orientations. They were defined as toe-in (TI) $30^{\circ}$ adduction, neutral (N, neutral), and toe-out (TO) $30^{\circ}$ abduction positions. Results: The downward phase time of TI was significantly shorter than those of N and TO. The flexion and valgus angle of N was greater than those of TI and TO at the moment of foot contact. At the instance of maximum knee flexion, N showed the largest flexion angle, and TO position had the largest varus and external rotation angles. Regarding ground reaction force (GRF) at the moment of foot contact, TO showed the forward GRF, while others showed the backward GRF. TI indicated significantly larger mediolateral GRF than others. As for the maximum knee joint force and joint moment, the main effect of different foot positions was not significant. Conclusion: TI and TO might be vulnerable positions to knee injuries because both conditions might induce combined loadings to knee joint. TI had the highest mediolateral GRF with a shortest foot contact time, and TO had induced a large external rotation angle during downward phase and the peak forward GRF at the moment of foot contact. Conclusively, N is the preferred landing foot orientation to prevent non-contact knee injuries.