• Proceedings of the KSME Conference
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• 2003.04a
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• pp.456-461
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• 2003

A fuel cell is an electrochemical device in which the energy of a chemical reaction is converted directly into electricity. By combining hydrogen fuel with oxygen from air, electricity is formed, without combustion of any form. Water and heat are the only by-products when hydrogen is used as the fuel source. Fuel cell stack consists of multi-layered unit cells. A unit cell consists of MEA and bipolar plates. The end plate of fuel cell stack should give a uniform distributed pressure to multi unit cell layers so as to reduce the contact resistance and to prevent the leakage of reactant gases and the damage of multi layer components. The current end plate is redundantly large and heavy. It makes the power per unit volume reduced. Topology optimization of end plate is conducted for mass reduction and enhancement of bending rigidity. The evaluation of the current design and the recommendation for the future design is remarked.

• Fashion & Textile Research Journal
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• v.8 no.5
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• pp.591-596
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• 2006

In order to analyze the tailorbility of different fabrics for men's suit, FAST system has been used for measuring the distribution of mechanical properties in this study. As results, cashmere mixed woolen fabrics showed the minimum degree in relaxation shrinkage, formability, and shear rigidity than any other fabrics, and also showed more than 6% as maximum level of extensibility. Thus, cashmere mixed woolen fabrics requires careful tailoring in lay-out, marking, and cutting. It is necessary to establish new tailoring criteria for automatic sewing with cashmere mixed woolen fabrics than any other fabrics, because they show more failure rate of tailorbility. There have been noticeably more variation of shrinkage and extension for woolen fabrics with cashmere mixed than 100% woolen fabrics by evaluating the formability of the suits when these are completed to suits through cutting and tailoring from fabrics. Especially nylon mixed woolen fabrics showed shrinkage overall, but polyester mixed woolen fabrics showed extension at waist area. Thus, it is necessary to adjust the appropriate overfeed rate considering the amount of shrinkage and extension while tailoring.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1525-1529
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• 2003

This paper describes the result of carbody load test. The purpose of the test is to evaluate an safety which carbody structure shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load and operating condition. Carbody material applied a stainless steel and an aluminum alloy, The stainless steel model is the carbody of a motor car which is delivering to KNR line 1 in 2002 and the aluminum alloy model is the carbody of a motor car which is delivering to GWANGJU line 1 in 2003.

• Textile Coloration and Finishing
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• v.7 no.1
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• pp.58-64
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• 1995

In this study, we attempted to expect the mechanical characteristics of the wool fabrics by knowing the yarns. Moreover, we believe that we could apply these results to fabric design. We investigated the relationship between the mechanical characteristics of yarns and fabrics. As results, we have found that bending rigidity, bending hysteresis, compressional energy and compressional linearity between yarns and fabrics had correlated more than r=0.5. Also, the correlation between regression and experimental values is r=0.5 in stiffness while it is r=0.67 in fullness. And regression values were larger than experimental ones in stiffness, but were not in fullness. The correlation between regressional and experimental values had 0.63 in THV. According to the study, it is possible to apply it to fabric design when our predicting the primary hand and the total hand values of the fabrics from the mechanical characteristics of the yarns.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.8-13
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• 2020

Carbon fiber-reinforced plastics (CFRPs) are extremely strong and light fiber-reinforced plastics containing carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and rigidity are required, such as in the aerospace, automotive, and ship superstructure industries. In CFRP drilling, the tool performance greatly varies depending on the tool shapes, cutting conditions, and diamond coating. This study developed a new type of tungsten carbide drill with multi-blade edges to evaluate the surface quality of CFRP materials according to the coating thickness of diamond-coated drills. Experiments on tool wear, surface roughness, and burr formation were conducted. The bore exit quality of a 12 mμ -coated drill was better than that of a 6 mμ -coated drill. The superior effects of the 12 mμ -coated drill and the good surface quality of CFRP were also demonstrated.

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.203-217
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• 2000

This review describes the overall knowledges of parkinson's disease. There are involved the causes. chemical characteristics, clinical features including tremor. bradykinesia, and rigidity. evaluation of movement disorders. and physical therapy of parkinson's disease. People who are diagnosed with parkinson's disease experience movement disorders that, if not managed, can lead to considerable disability. Before treated with parkinson's disease, it is important to recognise the pathogenesis of that. Then we need to develop physiotherapeutic programs based on the pathophysiology of parkinson's disease.

• Journal of Power System Engineering
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• v.14 no.6
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• pp.47-53
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• 2010

A stabilizer link connects the stabilizer bar to the lower arm of the suspension. When a vehicle is turning, lateral forces from the tire are transmitted through the stabilizer link into the stabilizer bar. The stabilizer bar will twist, thus adding rigidity to the vehicle body. In this study, the stabilizer link body was manufactured by using composite material with POM-GF25%. Therefore, the strength evaluation of stability link body with composite material carried out from tensile, wear and fatigue test. The tensile strength between the stability link body with composite material and the rod with knurling was the largest of four types of rod. In Analyzing materials property using optical sensing technique of stabilizer link for automobile parts, its has been identified the safety.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.211-215
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• 2004

This paper describes the result of structure analysis and load test of torque arm for driving gear unit. The purpose of the analysis and test is to evaluate an safety which torque arm shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load. Driving gear unit consist of gearbox and torque arm. Both components, torque arm is significant component subjected to the vehicle and motor loads. The evaluation methode is used the FEM analysis, static and fatigue test. The test results have been very safety and stable for design load conditions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.7-14
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• 2012

CFRP composite material has the superior specific strength and rigidity compared to metallic materials, and is widely adopted in the various fields. However, CFRP composite material has the weakness in hygrothermal and crash environment. Especially, moisture ingress into composite material under hygrothermal environment can change molecule arrangement and chemical properties. In addition, interface characteristics and material component properties can be degraded. A collapse experiment has been made to research the differences of absorbed energy and deformation mode between absorbed specimens of moisture and non-moisture. As a result of this study, the effect of moisture absorption and impact loads of about 30~50% reduction in strength are shown.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.156-161
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• 2002

This paper describes the result of carbody load test. The purpose of the test is to evaluate an safety which carbody structure shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load and operating condition. Carbody material applied a stainless steel and an aluminum alloy, The stainless steel model is the carbody of a motor car which is delivering to KNR line 1 in 2002 and the aluminum alloy model is the carbody of a motor car which is delivering to GWANGJU line 1 in 2003. This strength test is based on "performance test standard for Electrical Multiple Unit, noticed by Ministry of Construction ＆ Transportation, in 2000" and reference code is UIC 566 and JIS E 7105.