• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1614-1616
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• 1998

Insulation performance of major components of prefabricated joint such as epoxy insulation unit and premolded rubber cone are guaranteed by material selection design and proper manufacturing. On the other hand insulation performance of the interfaces between the premolded rubber cone and the epoxy insulation unit and the cable insulation is maintained by keeping the premolded rubber cone to close contact with such insulation by spring. Electric characteristics of a interface depend on the contact pressure, but the required characteristics are assured so far as a proper contact pressure is maintained. In this report, the interfacial pressure by pressure sensors both in the early stage and after heating cycle were measured and the simulation by FEM program were presented. The comparison of these two results show that interfacial pressure could be controlled optimally by changing the spring length and lubricant state of the interface.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.247-255
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• 2019

This study was conducted to investigate the effects of extrusion pressure and particle size of feed ingredients on the growth performance and plasma hormone activity in juvenile olive flounder Paralichthys olivaceus. Experimental diets were prepared with extrusion pressure manipulated by screw speed [low pressure (LP), 885 rpm/min; high pressure (HP), 708 rpm/min] and different dietary particle sizes [specific surface area: small (SS), $169.9m^2/kg$; large (LS), $67.4m^2/kg$] in a two-level factorial design. Four experimental diets (LP+SS, LP+LS, HP+SS, and HP+LS) were randomly assigned to 12 tanks (3 replicates) stocked with 20 fish (initial weight, 57 g) per tank. After a 4-week feeding trial, the observable trends of the main effects of extrusion pressure and particle size on growth performance showed that LP and SS enhanced fish weight gain. The plasma insulin-like growth factor-I level was significantly higher in fish fed the LP+SS diet than in fish fed the HP+SS diet. These results indicate that manipulation of the physical qualities of feed through adjustment of extrusion pressure and feed ingredient particle size may influence the growth performance of juvenile olive flounder, which should be considered in feed manufacture.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.69-80
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• 2007

The purpose of this study was to investigate the difference of ground reaction forces of swimming athletes during their starting motion and to find out the most effective starting motions which were used in swimming athletes. The subjects were 9 male and 8 female high school swimming athletes who were athletic career over 7 years and used three starting motions in competition. The ground reaction forces were measured from each athletes performing three starting motion each of the open grap starting motion, closed grap starting motion and track starting motion. For the measurement, the force platform of AMTI company was utilized, and the analysis on measured ground reaction forces were used of Biosoft(Ver. 1.0). The items measured were stance time, Fz max deceleration force and Fz max deceleration force time, Fz mid stance force and Fz mid stance force time, Fz max acceleration force and Fz max acceleration force time, Torque maximum and Torque maximum time, Torque average, Excursion along Y axis of center of pressure of foot, Excursion along X axis of center of pressure of foot, Length of center of pressure of foot, Average velocity of center of pressure of foot. The data measured by the closed grap starting motion, open grap starting motion and track starting motion were analyzed by one-way repeated ANOVA. The results were as follows ; 1. The Fz max deceleration force time, Fz mid stance force, Fz max acceleration force, Torque maximum and Torque maximum time, Excursion along Y axis of center of pressure of foot, Average velocity of center of pressure of foot were significantly fast and large in the closed grap starting motion then open grap starting motion and track starting motion. 2. The Excursion along Y axis of center of pressure of foot was significantly long in the closed grap starting motion then open grap starting motion and track starting motion.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.338-344
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• 2016

The study is actively being performed to increase fuel injection pressure of common rail system among countermeasures to meet the emission regulation strengthen of the Diesel engine. The common rail fuel injection tube in such ultra high pressure common rail system has the weakest structural characteristics against vibration that is generated by fuel injection pressure and pulsation during engine operation and driving. Thus the extreme durability is required for common rail fuel injection tube, and the drawing process is being magnified as the most important technical fact for strength of seamless pipe that is the raw material of common rail tube. In this respect, we analyzed the characteristic of dimension and stress variation of the ultra high pressure common rail fuel injection tube by variation of Die and Plug angle in drawing process. Based on the analysis, we tried to obtain the raw material strength of common rail fuel injection tube for applying to the ultra high pressure common rail system. As a result, Plug angle is more important than entry angle of Die and we could obtain the target dimension and strength of the ultra high pressure common rail fuel injection tube through optimization of Plug angle.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.228-238
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• 2005

Objectives : We conducted a randomized, double-blinded clinical trial to assess the anti-hypertensive effect of Ginseng and to know the difference of the effect according to it's growing districts md species by 24-hour ambulatory blood pressure measurement (ABPM). Methods : We allocated 96 hypertensive patients enrolled in this trial to Korean ginseng(KG), American ginseng (AG), Chinese ginseng (CG), and Korean red ginseng (KRG) groups by randomization. Each subject was administered 4.5mg/day of encapsulated ginseng for 4 weeks. We assessed anti-hypertensive effect, blood pressure variability using ABPM and toxicity by blood chemistry before and after treatment. We also evaluated changes of symptoms due to hypertension and adverse effect in all groups at the first visit, 2 weeks later and 4 weeks later. Results : Blood pressure after treatments showed significant decrease of systolic blood pressure (sBP) in the CG-group (p<0,05) and diastolic blood pressure (dBP) in the KRG-group (p<0.05). However, there were no significant changes of sBP (or dBP) after treatment in the other groups and no significant difference in changes of BP between before and after treatment among the 4 groups. Blood pressure variability in the CG-group showed significant decrease after treatment but not in the KRG-group. Symptoms such as headache or neck stiffness and heating sensation due to hypertension improved significantly in all groups, especially in the KRG-group. A3l patients had no adverse effect after treatment and there was no liver or kidney toxicity. Conclusions : CG and KRG seem to have anti-hypertensive effects, but there was no significantly different effect depending on growing district and species of Ginseng.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.12
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• pp.1722-1725
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• 2014

An experimental investigation of COP(center of pressure) was performed using FSR(force sensing resistor) and force plate. The FSR sensor system is used as effective device to detect the movement of human body in activities of daily living. It has been shown that the FSR provides the trajectories of COP with repeatability and reliability.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.417-422
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• 1998

The study was explored socket pressure distributions on a trans-femoral amputee with a suction socket in static and dynamic situations. Even when the amputee stood in the anatomically neutral position, significant pressure concentrations were observed in the lateral, medial, and posterior planes of the socket. During free level walking, a significant shifting pattern of pressure concentration areas was observed. High socket pressure was observed in the lateral, medial-anterior and posterior walls during mid-stance or push-off period. Socket pressure measurement will be one of the good tool to determine the optimal socket-limb interface.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.231-241
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• 2011

The purpose of this study was to analyze the distribution of foot pressure generated by active materials of a functional insole. Comfort is an important consideration while selectingfootwear and insoles. Consequently, it has an influence on injury. The development of new materials for functional insoles is considered one of the more important points for their manufacture. The method adopted in this study is as follows. First, ten healthy males were selected as subjects for the study. Each subject's foof was pre-screened podoscope(Alfoots, Korea) to check for the presence of any foot abnormalities, Two kinds of equipment were used for the study: a foot pressure device from Pedar-X, Germany, and a treadmill from Pulsefitness, UK. Next, each subject was asked to test four types of insoles(insoles of outdoor shoes, indoor shoes, walking shoes, and sports shoes) via walking trials on the treadmill at a constant speed of 4.2 km/h. The pressure distribution data(contact area, maximum force, maximum peak pressure, and maximum mean pressure) was collected using the pressure device at a sampling rate of 100 Hz. Results of the tests showed that all four types of functional insoles increased contact areas whit the foot. Further, functional insoles of walking shoes and sport shoes decreased the foot pressure. From these results, we conclude that the active materials of functional insoles of shoes can increase the contact area and provide greater comfort.

• Journal of the Korean Society of Safety
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• v.25 no.5
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• pp.7-14
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• 2010

Ultra high pressure system, which can be generally increased over 1,000bar, needs to have sealing mechanism to protect leakage and selection of the materials used in the intensifier. Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions. Components need to be tested under 1.5 to 3 times of rated pressure to check the tolerance even though rated pressure range of these components are not ultra high pressure. So, the ultra high pressure system needs to be equiped to test components. In this study, safety assessments of ultra high pressure system which are using failure analysis of components, changing the types of the control system, and finite element analysis with static condition, are investigated.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.83-98
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• 2004

The purpose of this study was to investigate the test-retest of plantar pressures using the F-Scan system over speeds and plantar regions. 6 healthy female subjects in 20's were recruited for the study. Plantar pressure measurements during locomotor activities can provide information concerning foot function, particularly if the timing and magnitude of the loading profile can be related to the location of specific foot structures such as the metatarsal heads. The Tekscan F-Scan system consists of a flexible, 0.18mm thick sole-shape having 1260 pressure sensors, the sensor insole was trimmed to fit the subjects' right. left shoes - sneakers shoes & dress shoes. It was calibrated by the known weight of the test subject standing on one foot. The Tekscan measurements show the insole pressure distribution as a function of the time. This finding has important implications for the development of plantar pressure test protocols where the function of the forefoot is important. According to the result of analysis it is as follows 1) Center of force trajectory in women's dress shoes display direct movement, compare with center of force trajectory in Sneaker shoes displays a little bit curved slow pronation movement. Sneaker shoes in forefoot part display very quick supination movement, therefore, this shoes effects negative effectiveness for ankle's stability Considering center of force trajectory analyzing the more center of force close straight line, the more movement can be quick movement for locomotion. For foot pressure distribution, center of force trajectory in locomotion is better to curved trajectory with pronation movement. So sneaker shoes style is good shoes considering center of pressure distribution trajectory compare with women's dress shoes. 2) Women's dress shoes increased peak pressure in medial, this is effected by high hill's height. The more increased women's dress shoes's height, the more women's peak pressure will increase, pronation can increase compare with before. Supination movement increase, this focused pressure in lateral, also, supination increased more. If the supination movement increased, foot pressure focused in lateral, therefore, it is appeared force distribution in gait direction. This is bad movement in foot's stability. 3) Women's dress shoes in landing phase displayed a long time, this is when women's dress shoes wear, gait movement is unbalance, so, landing phase displayed a long time. For compensation in gait, swing phase quick movement. 4) Women's dress shoes displayed peak pressure distribution in lateral of rearfoot part, Sneakers shoes displayed peak pressure distribution in medial of forefoot part. Its results has good impact absorption compare with women's dress shoes. In forefoot part, sneakers shoes has good propulsive force compare with women's dress shoes.