• The Journal of the Acoustical Society of Korea
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• v.21 no.4E
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• pp.178-182
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• 2002

In this paper, we propose an adaptive wavelet method for car interior noise cancellation. For this purpose, we use a node dependent threshold which minimizes the Bayesian risk. We propose a noise estimation method based on spectral entropy using histogram of intensity and a candidate best basis instead of Donoho's best bases. And we modify the hard threshold function. Experimental results show that the proposed algorithm is more efficient, especially to heavy noisy signal than conventional one.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.42-47
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• 2017

In these days, the size of urban is growing and the function of city becomes complicated. And also, in city, people lives a lot. The life of urban is getting closer and linked with neighboring people in many parts. Especially, when peoples are exposing during using public transportation, even though does not be known, in they were living. Seoul is the most crowded place in Korea. In Seoul,The village buses have been serviced to the narrow streets. And people who use this bus, wants to seek the comfort of the ride, air quality and noise during in vehicle. In this paper, we determine the degree of annoyance with the noise inside the town bus in dB scale. And, such a situation was confirmed annoyance see their effect. The Interior noise did not see a big difference in the new car and the old car. Annoyance but also according to the skill of the bus driver remains the difference was confirmed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.887-890
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• 2007

The low frequency noise, including infra-sound is known to affect human physiology and psychology. Guidelines and measurement method of low frequency noise has been introduced in several countries in order to evaluate low frequency noise. In this work, low frequency characteristics of Daejeon subway was investigated in terms of the noise level and spectrum in the interior of running subway car and the subway station. The interior sound pressure level of the passenger car was between 60 and 102 dB in the frequency range of $1{\sim}250$ Hz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.489-493
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• 2007

Mmulti-domain noise analysis method using Power Flow Boundary Element Method(PFBEM) has been developed successfully. Some applications are introduced. several examples. PFBEM is a numerical analysis method formulated by applying Boundary Element Method(BEM) to Power Flow Analysis(PFA). PFBEM is very powerful in predicting noise level in medium-to-high frequency ranges. However there are restrictions in analyzing the coupled structures and multi-media. In this paper, an analysis method for multi-domain acoustic problems in the diverse acoustic fields is suggested. And the developed method is applied to the car interior and exterior multi-domain noise analysis.

• Proceedings of the Korea Society of Design Studies Conference
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• 2004.05a
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• pp.284-285
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• 2004

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.65-68
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• 2003

Using composite materials for lilting train system has many advantages such as manufacturing variety, specific high-strength & stiffness characteristics, and long-life durability, but the strongest advantage could be the possibility of lightweight product. In the leading countries, the composite materials are used for the material fer drivers' cabs, interior/exterior equipments for railway train, and it is now developing the composite materials applied for the train car body structure. In this paper, we examine the use of composite materials for the drivers' cabs and interior/exterior equipments for the developing tilting train in Korea, and review the car body design using composite materials.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.154-157
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• 2001

자동차 인테리어 디자인에 있어서 색상은 외형디자인과 함께 사용자의 감성적 평가를 결정짓는 중요한 요인중의 하나이다. 그러나 이러한 중요성에도 불구하고 이에 대한 체계적인 연구가 이루어지지 않고 있는데 그 주된 이유로 자동차 프로토타입 모델의 완성 전에 가상적인 색상 배색 시뮬레이션을 해 볼 수 있는 기술적 기반이 미약했음을 들 수 있다. 다행히 최근의 컴퓨터 하드웨어 발달로 자동차 색상계획 단계에서 실시간으로 색채 배색효과를 시뮬레이션 할 수 있는 환경의 구축이 가능해지고 있다. 본 연구에서는 색상이미지에 대한 사용자 감성척도를 기반으로 색상 배색 디자인을 지원할 수 있는 자동차 인테리어 색상 배색 지원 시스템을 제안하고자 한다. 지원 시스템은 색상 감성 요소의 수집을 위한 정보수집 모듈, 색채 감성과 색상 속성의 상관관계를 추출하기 위한 컬러 감성 해석 모듈, 디자이너의 색상 배색을 지원하기 위한 시뮬레이션 모듈, 도출된 배색의 평가 테스트를 위한 평가 지원 모듈로 구성된다.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.327-332
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• 2003

We investigated the fire characteristics of the subway electric car's interior materials and evaluated the safety of it. The testing methods are ISO 4589-2 for Limited Oxygen Index, ISO 5658-2 for surface flame spread, ISO 5660-1 for Heat Release Rate, ASTM E 662 for smoke density and BS 6852 Annex B.2 for gas toxicity. The materials of seven organization including KNR were tested. Most of the materials are under the levels of the foreign country's demand. We also reported the test methods of other countries and compared it to ours.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.942-946
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• 2010

As the major sources of interior noise of train at running condition are the wheel/rail contact noise, the traction motor's noise and the driving gear's noise and these noise sources are transmitted through the car body, the noises of HVAC and air duct can be ignored. But the interior noise of train at standstill condition is decided by HVAC's noise and noise from the diffuser through the air duct. the interior noise prediction of train at standstill condition should be performed considering the shape of air duct, the air velocity and noise reduction property inside the air duct. But it is hard to estimate the interior noise level by the numerical method. Therefore train maker predict the interior noise level using The commercial noise prediction program. This paper introduce the noise prediction method of the train at standstill condition using the commercial program appling the ray tracing method and statistical energy analysis.

• Proceedings of the Korea Society of Design Studies Conference
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• 2002.05b
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• pp.244-245
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• 2002