• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.156-162
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• 2006

Pipe thinning is one of the major issues for the structural fracture of pipes of nuclear power plants. Therefore a method to inspect a large area of piping systems quickly and accurately is needed. In this paper, we proposed the method for monitoring pipe thinning. Our basic idea come from that a group velocity of impact wave is different as wall thickness. If the group velocity is measured, wall thickness can be estimated. To obtain the group velocity, time-frequency analysis is used. This is because an arrival time difference can be measured easily in time-frequency domain rather than time domain. To test the performance of this technique, experiments have been performed for a plate and U type pipe. Results show that the proposed technique is quite powerful in the monitoring pipe thinning.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.12 s.117
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• pp.1224-1230
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• 2006

Pipe thinning is one of the major issues for the structural fracture of pipes of nuclear power plants. Therefore a method to inspect a large area of piping systems quickly and accurately is needed. In this paper, we proposed the method for monitoring pipe thinning. Our basic idea come from that a group velocity of impact wave is different as wall thickness. If the group velocity is measured, wall thickness can be estimated. To obtain the group velocity, time -frequency analysis is used. This is because an arrival time difference can be measured easily in time-frequency domain rather than time domain. To test the performance of this technique, experiments have been performed for a plate and U type pipe. Results show that the proposed technique is quite powerful in the monitoring pipe thinning.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.9
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• pp.24-31
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• 2006

This study developed a human robot mast arm, which has a structure similar to the human arm, with the objective of taking over human works. The robot arm was structured to reproduce human actions using three axes on each of the shoulder and the wrist based on mechanics, and the actuator of each axis adopted an ordinary DC motor. The servo system of the actuator is a one body type employing an amp for electric power, and it was designed to be small and lightweight for easy installation. We examined the posture control characteristics of the developed robot mast arm in order to test its interlocking, continuous motions and reliability.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.300-305
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• 2007

This study developed a human robot master arm, which has a structure similar to the human arm, with the object of taking over human works. The robot arm was structured to reproduce human actions using three axes on each of the shoulder and the wrist based on mechanics, and the actuator of each axis adopted an ordinary DC motor. The servo system of the actuator is a one body type employing an amp for electric power, and it was designed to be small and lightweight for easy installation. We examined the posture control characteristics of the developed robot master arm in order to test its interlocking, continuous notions and reliability.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.221-226
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• 1997

This study was carried out for the hull form development of G/T 340ton class high speed fishery patrol ship by Chosun University at the Circulating Water Channel cooperatively with Korea Maritime Service. Same size of 15knots class fishery patrol ship was selected as a parent form (Model number : CU-015), and modified fore and after body to be suitable for the operation at 20 knots. To minimize the breaking wave in the vicinity of fore body at high speed zone, high bulb nose and slender fore body hull form was chosen as an initial condition. Meanwhile, to ensure the engine room space keeping high resistance-propulsion performance, U-type stern hull form was developed.

• Journal of Families and Better Life
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• v.3 no.1
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• pp.35-49
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• 1985

The Purpose of the study is to identify some factors affecting the consumer behavior of the Oriental students in the United States and provide some basic information for desirable consumer skills. The ninety subjects ere collected form the Oriental groups who were studying in Denton, Texas, U.S.A. Data were analyzed by frequency, percentage, mean, X2-test. The results are as follows: 1) There are significant similarities in the consumer behavior of the Oriental students regarding the information source, the preferred type of clothing, the factors affecting the choice of retail store, and the satisfaction after the clothing purchase. 2) There are some differences in the consumer behavior among three groups regarding expenditures of the purchase of clothing and the preferred choice of retail store. This study concludes that the Oriental students tend to: 1) adjust their life style to new situation ; 2) avoid their conflicts dur to the language barrier; 3) have a limited income to stay in the USA; and 4) have their own social acceptability based on their nationality.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.487-494
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• 2016

In order to comply with the Federal Motor Vehicle Safety Standard(FMVSS) No. 208 that has been in force since September 2003, an automatic airbag suppression system has become an essential option for detecting and protecting infants and children seated in the front passenger seat of vehicles in the U.S. market. MOBIS has developed the world's first weight-based OCS under the name NWCS. NWCS is composed of two sensors and ECU. It is sub-packaged in order to minimize the seat structure deviation. In this paper, technical features, robustness and performance of NWCS are summarized and discussed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.83-83
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• 2014

선박건조에 사용되는 도료 중 SPC(self-polishing copolymer) A/F(anti-fouling) 도료의 주된 기능은 해양생물의 부착 등 해양생물에 의한 오염을 방지하는 방오성능으로 인식되어 왔으나, 최근 방오성능 뿐 아니라 선박의 운항 시 선체저항을 줄임으로써 발생되는 연료절감효과와 선박의 미관을 위한 변색지연 등 SPC A/F 도료의 다른 기능에 많은 관심을 가지게 되었다. 이러한 관심과 사용자의 요구에 따라 도료사에서는 항력의 감소를 가져 올 수 있는 Silyl acrylate copolymer로 디자인 된 Silyl acrylate SPC A/F 도료를 개발하였으나 SPC A/F 도료의 방오제(biocides) 종류에 따른 방오성능 차이를 비교 평가 할 수 있는 객관적 자료가 부족하여, 본 연구를 통해 SPC A/F 도료의 종류 별 방오성능을 평가하고자 한다.

• Journal of the Korean Wood Science and Technology
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• v.12 no.1
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• pp.38-43
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• 1984

Water soluble urea-melamine-phenol copolymer adhesive manufactured with 80 percent of urea resin contents was manufactured by different molar ratio for a high temperature curing type, and their properties and strengthes were examined through manufactures of plywood with Kapur (Dryobalanops spp.) veneers. The results are summarized as follows: 1. Specific gravities of air dried plywood manufactured from each adhesive ranged from 0.78 to 0.84 and their moisture contents met the KS requirement. 2. In dry and wet shear strength, $U_{80}M_{10}P_{10}$ copolymer resin showed the highest value and urea resin was the lowest, indicating that melamine and phenol were effective for increasing glue shear strength of urea resin. 3. In case of glue shear strength after boiling test, phenolic resin was the nest and melamine was not so effective as phenol on reinforcement of boiling water resistance of urea resin.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.338-339
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• 2012

This study examined the friction and wear behavior of diamond-like carbon (DLC) films deposited from a radio frequency glow discharge using a hydrogen diluted benzene gas mixture. The DLC films were deposited on Si (100) and polished stainless steel substrates by r.f.-PACVD at hydrogen to benzene ratios, or the hydrogen dilution ratio, ranging from 0 to 2.0. The wear test was carried out in both ambient and aqueous environments using a home-made ball-on-disk type wear rig. The stability of the DLC coating in an aqueous environment was improved by diluting the benzene precursor gas with hydrogen, suggesting that hydrogen dilution during the deposition of DLC films suppress the initiation of defects in the film and improved the adhesion of the coating to the interface.