• 대한지리학회지
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• 제50권4호
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• pp.431-449
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• 2015

신자유주의의 사상적 기원과 논의구도는 매우 이질적이며, 접근방법도 아나키즘, 탈신자유주의를 포함하여 매우 다양하다. 2008년 금융위기를 계기로 신자유주의는 그 정당성과 안정성을 상실하기는 했지만 여전히 광범위한 변이들을 창출하면서 진화하고 있기 때문에 신자유주의 분석에서 공간적 관점의 중요성이 커지고 있다. 특히 신자유주의의 시공간 전략과 시스템 재생산을 위한 생성적 거점으로서 도시 공간이 핵심 무대가 되었다. 자본의 형식적 실질적 공간포섭으로서 신자유주의 도시화의 구체적 전개과정에서 가장 중요한 수단이 도시 인클로저이다. 현대 자본주의는 도시 인클로저를 통해 시초축적기의 원리를 현대적으로 재구성하여 탈취 기반 축적을 지속하고 있다. 이러한 도시 인클로저는 공적소유라는 본래의 공익개념으로부터 경제적 공익개념으로의 해석 변경과 사적자본의 이익을 위한 공용수용을 통해서 이루어지고 있다. 도시 인클로저는 생산 및 생존수단으로부터 노동자의 분리 소외를 더욱 심화시키는 물상화, 자유로운 장소향유의 제지, 세습가산제 형태로의 도시경제 전환을 동반하면서 인클로저의 일상화를 촉진하고 있고, 사적이익으로 뒤얽힌 사회적 규범들이 공적공간과 공간의 공공성을 지배하도록 만든다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.594-596
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• 2012

최근 야외 방송 및 공연에 대한 수요가 많아지고 있다. 이에 따라, 외부의 비와 같은 환경에서는 설치된 스피커에 침수와 같은 손상을 입을 수 있고, 이로 인해 진동 및 소음이 발생할 수 있다. 이에 따라, 본 논문은 이동용 라우드 스피커(Loud Speaker)의 방수효과를 개선하기 위한 실험적 연구를 수행하였다. 스피커의 성능 시험을 위해 MDF(Medium Density Fiberboard)를 이용하여 인클로저(Enclosure)를 제작하였고, 방수효과비교 실험을 위해 3가지의 마감재 즉 일반 페인트(Paint), 시트지(Sheet Paper), FRP(Fiber Reinforced Plastics)를 제안하였다.

• KASI NEWSLETTER
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• 통권83호
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• pp.5-5
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• 2008

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.240-241
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• 2009

The method of the reduction of the duct noise can be classified by the method of passive control and the method of active control. However, the passive control method has a demerit to reduce the effect of noise reduction at low frequency (below 500Hz) range and to be limited by a space. Whereas, the active control method can overcome the demerit of passive control method. The algorithm of active control is mostly used the Least-Mean-Square (LMS) algorithm because the LMS algorithm can easily obtain the complex transfer function in real-time. Especially, When the Filtered-X LMS (FXLMS) algorithm is applied to an ANC system.

• 한국소음진동공학회논문집
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• 제25권4호
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• pp.223-231
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• 2015

Enclosures are widely used to alleviate the contribution of machinery noise. It has been long concerned with the noise transmission through the access openings of the enclosures. In this study, we investigate active noise control technology for reduction of the transmission. A numerical model based on the acoustic boundary element method is first established. Using the numerical model, the acoustic transfer functions of the field points over the opening to the primary source at arbitrary locations are estimated. The feedforward control to minimize the acoustic power through the opening is then numerically implemented. The controller drives the secondary source to destructively interfere the noise transmission through the opening. Finally, a parametric study is conducted to evaluate the effects of the location and the number of the microphones on the control performance. Furthermore, the effects of the location of the secondary source on the performance of active noise control are investigated. It is followed that the control system implemented in this study leads to a significant reduction of about 31.5 dB in the sound power through the opening using only one secondary source located at the optimized position.

• 한국소음진동공학회논문집
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• 제22권8호
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• pp.756-762
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• 2012

A method of the low-frequency noise reduction in an enclosure by using an array of Helmholtz resonator is presented. An integral form of equation, which represents the acoustical coupling between the internal sound field and the resonator array, is formulated so that the boundary element method can be applied to solve the coupling problem. It is shown that the resonator array on the surface of the enclosure can be regarded as impedance patches on the boundary element. Experiments on a simple enclosure acoustically coupled with an array of resonators are conducted to verify the method. The predicted noise reduction by the boundary element method shows good agreement with the measured one. The effects of the resistance of resonators as well as the number of resonators on the noise reduction are demonstrated. As a practical example, the presented method is applied to the payload fairing of a space launcher with resonator arrays. It is demonstrated that the resistance of resonators affects significantly the required number of resonators to achieve a desired noise reduction.

• 한국소음진동공학회논문집
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• 제25권3호
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• pp.191-198
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• 2015

Noise propagated through the ventilation openings of enclosures is actively controlled using an FIR filter. The enclosures considered in this paper are used for isolating noise due to machinery. This method is of limited use because of the ventilation openings through which most of noise is propagated. Feedforward control strategy is incorporated to minimize the acoustic power propagated through the openings. For the real-time implementation, although it is numerical study, the controller is implemented using an FIR filter. The acoustic transfer functions of the pressure on the openings of the enclosure to the primary source and to the secondary source are numerically calculated using the boundary element method. The performance analysis of the active control is conducted with the time-domain simulation using Matlab Simulink.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.796-802
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• 2013

In this study, we investigates active control technology to reduce the noise transmitted to the outside through the opening of enclosures. A numerical model based on acoustic boundary element method is first established. Using the numerical model, the acoustic transfer functions of the field points over the opening to the primary source at arbitrary locations are estimated. The feedforward control to minimize the acoustic power through the opening is then numerically implemented. The controller generates the secondary source to destructively interfere the noise transmission through the opening. Finally, a parametric study is conducted to evaluate the effects of the location and the number of the microphones on the control performance. Furthermore, the effects of the location of the secondary source on the performance of active noise control are investigated. It is followed that the control system implemented in this study leads to a significant reduction of about 35dB in sound power through the open using only on secondary source located at the optimized position.

• The Journal of the Acoustical Society of Korea
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• 제13권1E호
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• pp.37-44
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• 1994

저주파 대역에서의 스피커 왜곡을 무향실 없이 측정할 수 있는 방법을 제안한다. 이 방법은 제 n고조파의 경우 밀폐형 스피커 내부에 비해 외부에서 40log n dB 증폭된다는 사실에 기초를 두고 있다. 인클로저 내부의 정재파에 의한 영향을 상쇄함으로써 측정가능한 주파수 대역을 넓혔으며 측정오차의 원인을 분석하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.670-672
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• 2014

In this study, we investigate active control of noise transmitted through a window of enclosures minimizing the acoustic power. To reduce noise of the enclosures, passive methods with absorbing material are generally used. The passive methods, however, are limited use due to the vantilation windows. In this case, these windows are path of noise leakage. Feedforward active noise control technology is applied to minimize the sound power from the enclosure. The feedforward controller is implemented with FIR filter based on the transfer functions calculated numerically. The controller reflects the delay due to FIR filter. The noise transmitted through the window is actively controlled, and the reduction of the power is obtained by 15dB.