• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.3
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• pp.219-226
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• 2014

A bus duct system for wind tower is introduced. A marine cable has been widely used in wind tower or various offshore structures. However, as the electric load capacity is increases, large number of cable lines must be used to cover the huge amount of electric capacities. Therefore, the installation of the cable lines becomes very difficult due to the heavy weight and volume of the cables. On the other hand, by using a single bus duct system line, the power capacity amount of 16 cables can be delivered with significantly compacted form. However, unlike flexible cables, the bus duct is relatively stiff which could generate the resonance phenomenon in the operating condition of the wind tower. In this study, the vibration characteristics of the bus duct are investigated and its long-term reliability during the life time of the wind tower is verified.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.68-73
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• 2002

It is necessary first to understand dynamic characteristics of bus full BIW assembly for fatigue endurance analysis. FE model has been used usually for analyzing the dynamic behavior of structures. A lot of experience and effort, however, is necessary to make the credible FE model. Experimental modal analysis of structures has been performed to verify the credibility of initial FE model and to update the model. In this work, experimental modal analysis was performed to understand dynamic characteristics of bus full BIW assembly in free-free boundary condition and the result was used to verify the initial FE model. In addition, some practical techniques, which were used in this experiment, were mentioned.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.12
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• pp.1276-1282
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• 2003

The SMT(Surface Mount Type) ferrite bead used to reduce the influx of power bus noise is modeled with parallel capacitor(C), series resistor(R) and series inductor(L). The simple equivalent circuit modeling doesn't agree with the measurement result. In this paper, we proposed the accurate equivalent circuit model of the ferrite bead at wide frequency range(50 MHz∼3 GHz) and analyzed the noise effect to the high speed IC(Integrate Circuit) with ferrite bead or not.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.584-590
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• 2009

Since driving include compilcated actions that require a variety of abillity and cause extrme concentration or strain, divers tend to feel tired easiy. However, divers can't recognize fatigue degree by himself and accordingly the methods to measure quantitative fatigue degree exactly is quite difficult to be secured. In this study, the most efficient driving posture was suggested based on the analysis of quantitative muscular strength and fatigue degree according to posture. The driver whom we experimented included 9 commercial bus drivers. We also analyzed quantitative legs' muscular strength according te operating each pedal, left and right then we analyzed muscular strength and muscular fatigue degree according to driving pattern while driving commercial buses. And then we suggested the most efficient driving posture.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.314.2-314
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• 2002

It is necessary first to understand dynamic characteristics of a bus full BIW assembly for fatigue endurance analysis. FE model has been used usually for analyzing the dynamic behavior of structures. A lot of experience and effort, however, is necessary to make a credible FE model. Experimental modal analysis of structures has been performed to verify the credibility of initial FE model and to update the model. (omitted)

• Journal of the Korean Society of Safety
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• v.10 no.4
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• pp.13-21
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• 1995

On mini-bus with diesel engine, at idle rpm for taking measurement to reduce gear rattle noise, was tested by the three clutch disc samples by turns, then measured the fluctuation of revolution of engine & transmission and parallel vibration of differential gear & transmission. By analyzing the measured data, the gear rattle noise, the matching design and tuning technic of transmission are comprehended and established. Conclusions of this test are as follows ; (1) Fluctuation of revolution on transmission is greatly affected by torsion of clutch disc according to fluctuation of engine revolution transmit to transmission through clutch system. Especially, gear rattle noise can be reduced by minimaizing the fluctuation of the revolution of transmission using pre-damper type clutch disc. (2) The reason of gear rattle noise is higher in summer than winter and driving longer period than initial driving is due to affection by drag torque changing. So, it is necessary for manufacturer to choose proper oil to transmission. (3) It can be occurred jumping and crash noise by applying the pre-damper type clutch disc for reducing the gear rattle noise. So, it is necessary to do test with actual vehicle according to test procedure.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.87-88
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• 2017

오늘날 도시의 규모가 커지고 도시의 기능이 점점 복잡해진다. 또한, 도시에는 사람들이 많이 살고 있으며, 계속해서 도시로 사람들이 모이게 된다. 그러므로 도시에서의 삶은 서로 간에 점점 더 가까워지고 많은 부분에서 이웃 사람들과 연결되고 공간과 시간을 공유하게 된다. 특히, 사람들이 대중교통을 이용하면서 원하든 원치 않았든 많은 소리에 노출 되며, 그 소리에 대한 영향으로 서로 피해를 보기도 한다. 서울은 세계에서 가장 혼잡한 도시 중 하나이며, 이런 서울의 대중교통 중 마을버스는 좁은 골목길을 포함해 도로를 다니며 시민들의 공공의 이동을 담담하고 있다. 이 마을버스를 사용하는 사람들은 일반적으로 차량 내에서 좋은 승차감, 높은 공기질 및 적은 소음에서 이용하기를 원한다. 본 논문에서는 마을버스의 실내 소음에 대한 성가심도를 소음도 및 혼잡도에 관하여 분석한다. 그리고 이러한 상황별로 어떠한 경우에 성가심도가 높은지를 판단하고, 저감하는 방법을 마련하도록 하고자 한다. 분석결과 마을버스 내부 소음은 새 차와 오래된 차에서 큰 차이를 보이지 않았고, 성가심도 또한 도로 상황에 따른 소음의 정도에 민감한 반응을 보임을 확인하였다. 그래서 저감대안으로는 차량의 소음이 적게 발생 시키는 운전과, 차량의 정비 등을 제안하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.256-257
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.69-69
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.345-346
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• 2011