• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.22-30
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• 2011

This study analyzes harmonic vibration with natural frequency according to the configuration of damper clutch. In the case of double spring, equivalent stress at same direction of the revolution at inner and outer coil spring is over 30% as compared with at its opposite direction. Natural frequency or harmonic response with maximum deformation in case of the less coil pitch is below 3Hz as compared with in case of the more coil pitch. As the coil pitch of damper spring as the case 2 or 4 becomes smaller, its mass and deformation can be large. In these cases, spring constant and natural frequency become smaller. In the case 5 or 6 of double spring at natural vibration or harmonic response, the frequency becomes over 300Hz. As the result of this study is applied by the design of damper spring, the damage at its connected part is prevented and the durability can be predicted.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.903-908
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• 2007

A retractor is the major component of a seatbelt system that restraints passengers by locking the movement of webbing. Recently, in order to increase the effectiveness of seatbelt systems, motorized retractors that remove slack and correct passenger posture just before airbag expansion when collision is predicted are widely used. Key component of motorized retractors is the one-way clutch that engages and disengages the winding action of webbing according to the direction of motor revolution. Analytical investigation of action of the one-way clutch mechanism has been carried out to figure out conditions for one-way locking, and to study the effect of various kinematic and dynamic design variables of one-way clutch. Using combination of ADAMS and LifeMOD soft-wares, dynamic simulation of operation of motorized retractors including Hybrid-III dummy model has been carried out to evaluate the performance of the motorized retractors in various crash scenarios.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.637-639
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• 2005

정보 통신 기술의 빠른 발전으로 인해 차량이 단순한 운전 공간이 아닌 다양한 서비스를 이용할 수 있는 복합적 환경으로 변모해 강에 따라 텔레매틱스라는 말이 더 이상 낯선 말이 되지 않고 있다. 이에 세계의 여러 나라들은 이와 관련된 IT 산업에서의 경쟁력 확보를 위해 핵심 기술을 더욱 연구 개발하고 있다. 본 논문에서는 텔레매틱스 기술을 발전시키고, 관련 산업을 더욱 활성화 시키기 위하여 현재 진행중인 제주 텔레매틱스 시범 서비스에 대해 소개한다. 제주 텔레매틱스 시범 서비스는 향후 관련 기술의 향상과 국외 텔레매틱스 기술에서의 주도권 확보를 통하여 한국이 텔레매틱스 강국이 되는 것을 목표로 하고 있다.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.207-212
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• 2003

Recently there has been a remarkable increase in the number of high speed and large ships, and the high power involved for propulsion of above ships have brought high pitch ratio and high skew propeller. The recent tendency toward highly skewed propeller has increased the load on propeller blades and the fatigue strength of propeller blades has become the critical point in design of propellers for above ships. In this paper fatigue tests in sea water were carried out on propeller material of Ni-Al bronze. The stress and environmental conditions of the test were selected to be close to those of full size propellers in use. The effect of stress ratio, stress frequency, revolution number of propeller for above ships numbers and so on were discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.84-89
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• 2004

This study is a basic one for application of ER Fluid to fluid power systems. By mixing silicone oil with zeolite particles, four kinds of ER fluids were made, in which the weight ratio of zeolite particles are different. We examined how the Yield shear stress and Bingham characteristics of the ER fluids are effected by varying electric field intensity. We designed and constructed a disk type power transmission clutch in which ER fluid fills and this ER fluid transmits the power of drive shaft to the driven shaft. With this equipment, the revolution transmission ratio from the chive shaft to the driven shaft by varying electric field density of the ER fluid was examined.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.107-112
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• 2012

Air flow and its pressure at electric fan according to three, four and five blades are analyzed in this study. As the number of blades increases at the same condition of specification, air tends to converge and becomes natural wind but higher power is consumed. And the velocity of wind is decreased as the space between winds becomes narrow. The turbulent flow is happened in the center of the body of revolution and the kinetic energy becomes largest in case of three blades. The pressure is decreased than atmospheric pressure from fan to outlet. As the number of blades increases, the pressure drop becomes smaller and is smallest in case of the fan with three blades. As the study result, The electric fan with three blades is thought to be effective in view of power consumption and design.

• Proceedings of the Korea Society of Costume Conference
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• 2003.10a
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• pp.40-40
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• 2003

People calls the 21th century when they have just entered 'the age of culture'. In the end of the last country, they reflected the trend of materialism and with this the business of knowledge, art and culture which leaded the information revolution arose as the dominant form of industry. The world opened 'the age of culture'. In the new paradigm called 'the age of culture', the color has become the leading medium to change the comtemporary vision. At this time, this study has diversely considered about purple displayed in the modern fashion.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.942-945
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• 2003

Noise cause is dividing to fluid noise by exhaust flow of fan and vibration noise by rotational vibration of motor. Until now, measuring method has been used to measure vibration by the accelerometer, this method has been not measured for the vibration in some parts of brush and commutator because of motor construction. This research was purposed on the accurate analysis. using laser vibration analyzer, of noise cause against the difficult part in old times. By using this measured data, we would like to use for the design of silent motor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.179-184
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• 2003

Noise cause is dividing to fluid noise by exhaust flow of fm and vibration noise by rotational vibration of motor. Until now, measuring method has been used to measure vibration by the accelerometer, this method has been not measured for the vibration in some parts of brush and commutator because of motor construction. This research was purposed on the accurate analysis, using laser vibration analyzer, of noise cause against the difficult part in old times. By using this measured data, we would like to use for the design of silent motor.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.240-243
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• 2008

In this paper, the design of Centrifugal Compressor which is used in sizes 50 horse power has 8 pressure ratio and numerical analysis of the flow within compressor varying tip clearance length are performed. To get high pressure ratio with low power the exit height of impellers is low but compressor has very high speed of revolution. So compressor has high specific speed although mass flow rate is very small. The shape of impellers at the first stage is carried out. Flow and performance characteristics of impellers has been analyzed by using a commercial CFD program, $Fine^{TM}$/turbo. The result shows that loss coefficient is affected by tip clearance length and compressor has proper tip clearance length. It is possible to decrease loss by selecting apt tip clearance length.