• 동력기계공학회지
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• 제14권2호
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• pp.55-59
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• 2010

In the study, it is considered sporty car as 1400cc entry cars using sound generator. These cars are required special sound quality, also sporty sound quality. The operational principle of this sound generator system is that on the operation of the engine intake valves caused pulsating is to shake the membrane of the sound generator on the inside of the driver front dash panel through the intake manifold, which will deliver the required sound quality and tone. For the component constructed sound generator, main design parameters are selected and optimized using the daguchi's method. The results are as follows; The C2 sound level must be minimized and C4 level must be maximized. And also overall level keeps linear characteristics.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.506-515
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• 2023

This study is to find a method to learn engine sound after the start-up of a diesel generator installed in nuclear power plant with an unsupervised deep learning algorithm (CNN autoencoder) and a new method to predict the failure of a diesel generator using it. In order to learn the sound of a diesel generator with a deep learning algorithm, sound data recorded before and after the start-up of two diesel generators was used. The sound data of 20 min and 2 h were cut into 7 s, and the split sound was converted into a spectrogram image. 1200 and 7200 spectrogram images were created from sound data of 20 min and 2 h, respectively. Using two different deep learning algorithms (CNN autoencoder and binary classification), it was investigated whether the diesel generator post-start sounds were learned as normal. It was possible to accurately determine the post-start sounds as normal and the pre-start sounds as abnormal. It was also confirmed that the deep learning algorithm could detect the virtual abnormal sounds created by mixing the unusual sounds with the post-start sounds. This study showed that the unsupervised anomaly detection algorithm has a good accuracy increased about 3% with comparing to the binary classification algorithm.

• 한국통신학회논문지
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• 제21권11호
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• pp.2978-2990
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• 1996

With the advent of multimedia era, there are ever increasing interest in computer music and sound syntheis. An FM type sound synthesizing method makes possible the syntheis ofvarious sounds ofmusical instruments with a relatively simple hardware architecture. Therefore, in this paper, we designed a hardware architecture for real-time sound synthesizer and its logic gates. In this paper, we designed a basic sound generator for implementation of real-time logic gates, analzed characteristics of sounds synthesized in this architecture and extracted parameters of FM sounds of musical instruments by using the Csound software. The major bolkcs to build the hardware are a phase-generator, a singe-function-generator, an envelope-generator and a multiplier-part. Finally, logic circuits are designed and verified in VHDL and logic gates by 1.0um standard cell library, which will be easily implementable by the form of ASIC.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.527-532
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• 2014

Generator is the main equipment of a power plant that generates electric power. The line frequency is 60Hz, since that is operated at 3600rpm in fossil power plant. Therefore, the specific frequency 120Hz by the electromagnetic excitation force is generated inherently. If the looseness of stator at generator happens, abnormal sound that has 120Hz and the harmonic frequency is emitted from generator frame. In that case, binding of end-winding or re-wedging is needed for the reduction of sound level. In case of severe level of sound, belly band can be additionally installed at core. In this paper, the characteristics of generator sound is described and modal data is analyzed after installation of belly band.

• 한국정보통신학회논문지
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• 제4권5호
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• pp.1017-1025
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• 2000

인간의 청각시스템은 두 가지 요소 즉, ITD(Interaural Time Difference)와 IID(Interaural Intensity Difference)를 처리하여 음원의 위치와 추적을 하고 있다. 본 연구에서는 음원의 위치 검출을 위하여 ITD와 IID 뿐만 아니라 이전의 위치 정보를 이용하여 정확한 음원의 방향을 결정할 수 있는 TEPILD(Time Energy Previous Integration Location Detector) 모델을 제안하였다. TEPILD 모델에서 time function generator는 ITD, energy function generator는 IID를 처리할 수 있도록 하였다. 음원은 정현파(500Hz,1kHz, 2kHz, 3kHz), White noise, Pink noise, News, Music으로 하고 음원의 방향은 right, front right, front, front left, left로 하였다. 실험 결과 전체 평균 정확도가99.2로 좋은 결과를 얻을 수 있었으며, TEPILD가 음원 위치 검출기에 이용될 수 있음을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1129-1130
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• 2013

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1037-1041
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• 2007

With the advent of sound field simulator, many sound fields have been reproduced by obtaining the impulse responses of specific acoustic spaces like famous concert hall, opera house. This sound field reproduction has been done by the linear convolution operation between the sound input signal and the impulse response of certain acoustic space. However, the conventional finite impulse response based linear convolution operation always makes real-time implementation of sound field generator impossible due to the large amount of computational burden. This paper introduces the fast convolution method using perceptual redundancy in the processed signals, input audio signal and room impulse response. Temporal and spectral psycho-acoustic filters considering masking effects are implemented in the proposed convolution structure. It reduces the computational burden of convolution methods for realtime implementation of a sound field generator. The conventional convolutions are compared with the proposed one in views of computational burden and sound quality. In the proposed method, a considerable reduction in the computational burden was realized with acceptable changes in sound quality.

• 한국소음진동공학회논문집
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• 제18권2호
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• pp.231-237
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• 2008

With the advent of sound field simulator, many sound fields have been reproduced by obtaining the impulse responses of specific acoustic spaces like famous concert hall, opera house. This sound field reproduction has been done by the linear convolution operation between the sound input signal and the impulse response of certain acoustic space. However, the conventional finite impulse response based linear convolution operation always makes real-time implementation of sound field generator impossible due to the large amount of computational burden. This paper introduces the fast convolution method using perceptual redundancy in the processed signals, input audio signal and room impulse response. Temporal and spectral real-time masking blocks are implemented in the proposed convolution structure. It reduces the computational burden of convolution methods for real-time implementation of a sound field generator. The conventional convolutions are compared with the proposed one in views of computational burden and sound quality. In the proposed method, a considerable reduction in the computational burden was realized with acceptable changes in sound quality.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.662-667
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• 1994

This paper presents the design and construction details of a soundproof enclosure for housing 20 KVA diesel generator-set. As the generator had to be installed close to the hospital building, it was desirable to reduce the transmission of noise by housing the generator in such an enclosure. The diesel engine being an air cooled one, it was essential to supply fresh air into the enclosure for its cooling. Forced inflow of air is provided through an inlet duct located in such a way that the incoming fresh air is thrown close to the inlet of cooling fan of the engine. The high velocity air stream, which heats up while passing over the engine head, escapes to the atmosphere through a rectangular outlet duct with enlarges inlet that receives hot air from the engine. The air ducts were designed specially and have been provided with acoustic lining for sound absorption. The masonary enclosure has been provided with double glazed fixed windows and double doors. The exhaust pipe of the engine fitted with a muffler has been taken out through the enclosure wall facing away from the hospital. Acoustic performance studies conducted in terms of attenuation provided by the enclosure at different frequencies have also been presented and discussed. The noise control measures adopted for building the sound-proof enclosure have been found to be quite effective as the noise levels inside the hospital building are now within the acceptable limits.

• 음성과학
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• 제11권3호
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• pp.175-180
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• 2004

In case of the hearing impairment with tinnitus and increased sound sensitivity, it is known that the patients tend to appeal the psychologically oriented social handicap rather than communication disability. The audiologist who is responsible for such patients in aural rehabilitation should pay special attention to the counseling techniques including tinnitus retain therapy (TRT), ear protector, noise generator, or specific acoustic training based on close cooperation and rapport. And then the audiologist should try to lessen their reaction to the tinnitus by using a hearing aid. This therapies tries to focus not a. total approach but a treatment to lessen the severity of tinnitus. This paper as a case report that a unilateral sharply slopped sensorineural hearing impaired person with tinnitus and increased sound sensitivity by using four channel digital signal processing (DSP) hearing aid with programming increment at low level (PILL).