• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.203-204
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• 2010

• Nuclear Engineering and Technology
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• v.29 no.3
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• pp.229-239
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• 1997

To investigate the realistic behavior of mass and energy release and resultant containment response during large break Loss of Coolant accident (LOCA), analyses are performed for Yonggwang (YGN) 3&4 nuclear power plants by using a merged version of RELAP5/CONTEMPT4 computer code. Comparative analyses by using conservative design computer codes are also peformed. The break types analyzed are the double-ended guillotine breaks at the cold leg and hot leg. The design analysis resulted in containment peak pressure during post-blowdown phase for the cold leg break. However, the RELAP5/CONTEMPT4 analyses show that the containment pressure has a peak during blowdown phase, thereafter it decreases monotonously without the second port-blowdown peak. For the hot leg break, revised design analysis shows much lower pressure than that reported in YGN 3&4 final safety analysis report. The RELAP5/CONTEMPT4 analysis shoos similar trend and confirmed that the bypass flow through the broken loop steam generator during post-blowdown is negligibly small compared to that of cold leg break. The low pressure and temperature predicted tv realistic analysis presented in this paper suggest that the design analysis methodology contains substantial margin and it can be improved to provide benefit in investment protection, such as, relaxing plant technical specifications and reducing containment design pressure.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.264-269
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• 2019

This paper presents mechanical design and control of a bio-inspired legged robot. To achieve a fast legged running mechanism, a novel linkage leg structure is designed based on hind legs of domestic cats. The skeletomuscular system and parallel leg movement of a cat are analyzed and applied to determine the link parameters. The hierarchical control architecture is designed according to the biological data to generate and modulate desired gaits. The effectiveness of the leg mechanism design and control is verified experimentally. The legged robot runs at a speed of 46 km/h, which is comparatively higher speed than other existing legged robots.

• Journal of Auto-vehicle Safety Association
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• v.7 no.1
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• pp.27-32
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• 2015

In order to protect occupant during car crash accident, Regulation and NCAP(New Car assessment Program) have been developed among various countries like U.S.A., Europe, Korea and Australia. Especially NCAP scores affect to sales of vehicles. So vehicle makers are trying to get good score in NCAP. Low leg injuries play an important role in Australia and Euro NCAP and these injuries are related with footrest design. Optimization of footrest design in early stage of vehicle development is necessary to obtain better and robust results of low legs during crash tests. In this paper, DFSS method and finite element model were used to optimize the low leg performance in small RHD vehicles. Compared with the lower leg injury of base model, the lower leg injury of proposed model was slightly improved and robustness was enhanced also.

• Korean Journal of Human Ecology
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• v.24 no.4
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• pp.555-569
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• 2015

During a design process of a protective equipment for sports activities, minimizing movement restrictions is important for enhancing its functions particularly for protection. This study presents a three-dimensional(3D) modeling methodology for designing baseball catcher's leg guards that will allow maximum possible performance, while providing necessary protection. 3D scanning is performed on three positions frequently used by a catcher during the course of a game by putting markings on the subject's legs at 3cm intervals : a standing, a half squat with knees bent to 90 degrees and 120 degrees of knee flexion. Using data obtained from the 3D scan, we analyzed the changes in skin length, radii of curvatures, and cross-sectional shapes, depending on the degree of knee flexion. The results of the analysis were used to decide an on the ideal segmentation of the leg guards by modeling posture. Knee flexions to 90 degrees and to $120^{\circ}$ induced lengthwise extensions than a standing. In particular, the vertical length from the center of the leg increases to a substantially higher degree when compared to those increased from the inner and the outer side of the leg. The degree of extension is varied by positions. Therefore, the leg guards are segmented at points where the rate of increase changed. It resulted in a three-part segmentation of the leg guards at the thigh, the knee, and the shin. Since the 120 degree knee-flexion posture can accommodate other positions as well, the related 3D data are used for modeling Leg Guard (A) with the loft method. At the same time, Leg Guard (B) was modeled with two-part segmentation without separating the knee and the shin as in existing products. A biomechanical analysis of the new design is performed by simulating a 3D dynamic analysis. The analysis revealed that the three-part type (A) leg guards required less energy from the human body than the two-part type (B).

• Journal of Korean Academy of Nursing
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• v.38 no.2
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• pp.278-286
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• 2008

Purpose: This study was done to compare edema and pain after completing a nurse's daily shift and to examine the effects of self leg massage which was usually used for reducing nurses' lower extremity edema and pain after their shift. Methods: The research design was a nonequivalent control group pretest-posttest design. Study subjects were 81 nurses who took a self leg massage program created by the researcher. Self leg massage was done 15 times during 3 weeks. Data were collected from September 21 to October 31, 2007. The level of lower extremity edema was measured by ankle and calf circumference by a tapeline in cm and the pain score was measured by using a subjective numbering rating scale. Data were analyzed with the SPSS 12.0 program using statistics of repeated measures ANOVA. Results: There was a statistically significant difference in pain according to the department. There was a statistically significant difference in lower extremity edema and pain in nurses after their shift and self leg massage. Conclusion: Self leg massage was effective for relieving nurses' lower extremity edema and pain. Therefore, it is proposed that standardized self leg massage should be applied as a method for nurses' lower extremity edema and pain.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.5
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• pp.257-263
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• 2000

One of the basic assumptions in the static gait design for a walking robot is that the weight of leg should be negligible compared to that of body, so that the total gravity center is not affected by swing of a leg. Based on the ideal assumption of zero leg-weight, conventional static gait has been simply designed for the gravity center of body to be inside the support polygon, consisting of each support leg's tip position. In case that the weight of leg is relatively heavy, however, while the gravity center of body is kept inside the support polygon, the total gravity center of walking robot can be out of the polygon due to weight of a swinging leg, which causes instability in walking. Thus, it is necessary in the static gait design of a real robot a compensation scheme for the fluctuation in the gravity center. In this paper, a body impedance control is proposed to obtain the total gravity center based on foot forces measured from load cells of a real walking robot and to adjust its position to track the pre-designed trajectory of the corresponding ideal robot's body center. Therefore, the walking stability is secured even in case that the weight of leg has serious influence on the total gravity center of robot.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1593-1596
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• 1997

Because the leg mechanism of walking roblt affect on the mobility and energy efficiency, we focus on the design of new leg mechanism based on the previous leg mechanisms. We mention the deficiency of the previous leg mechanisms and propose a new leg mechanism that consists of a 2-d.o.f pantograph mechanism and a vertical linear actuator. The pantograph mechanism is attached to the horizontal plane of the body and the verical linear actuator is vertical to that plane. In order to design a quadruped walking robot, we consider the kinematics of the 2-d.o.f pantograph mechanism and the arrangement of twol linear motion guides that drive the pantograph mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.326-330
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• 2004

This study is object to design and structural analysis of Leg Extension Machine. Design tool is AutoCAD and structural analysis of Leg Extension Machine using result from ANSYS Code. This structural analysis results, many variables such as boundary condition, constraint condition and load condition are considered.

• Journal of the Korean Home Economics Association
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• v.39 no.10
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• pp.97-109
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• 2001

It is thought that a composition of trousers is related to fabrics with single breadth. Therefore, trousers are designed with pattern using this fabrics with single breadth. However, in the old pattern of trousers, the breadth of 33cm-35cm was not considered in designing patterns. In this context, deciding which pattern design is better is not easy as there are a variety of estimation methods. So in this study, standardization of drafting is pursued by an objective pattern design. For this, a base angle of the trouser closely relating to a form and function was measured and using the height and the base angle, a trouser pattern design was tried. For a measurement of the base angle, 5 subject were selected. They are 25-29 year-old male graduates with fine physical standard. The base angle was measured with symphysis pubis point as a standard when subjects sat with their legs crossed, when they stood with their legs open (not forced artificially) and when they laid down with their legs open. The distance between a knee inside joint and knees was measured three times and the resultant value was used for the pattern design. For a design of trousers, the height was applied and the base angle was fixed. As a pattern drawing, using the height, a base angle and circumference of the hip, a trouser was designed. The production method for the pattern design is as follow: (1) The length formula, is height + $\frac{height}{2}$ (2) The hip girth formula is $\frac{hipgirth}{2}$ - $\frac{hipgirth}{20}$(3) A crotch angle is fixed at $72^{\circ}$. (4) The ratio of outer leg length to leg width is 5 : 8. (5) The component ratio of the upper outer leg length to the pant length is 5 : 8. (6) The ratio of the division point of front right inner leg length and left inner width to upper outer leg length is 5 : 8.