• 방송공학회논문지
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• 제27권6호
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• pp.885-896
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• 2022

제조에서의 모터 불량은 향후 A/S 및 신뢰성에 중요한 역활을 한다. 모터의 불량 구분은 소리, 전류, 진동등의 측정을 통해 검출한다. 본 논문에서 사용한 데이터는 자동차 사이드미러 모터 기어박스의 소리를 사용하였다. 모터 소리는 3가지의 클래스로 구성되어 있다. 소리 데이터는 멜스펙트로그램을 통한 변환 과정을 거쳐 네트워크 모델에 입력된다. 본 논문에서는 불량 모터 구분 성능을 올리기 위한 데이터 증강, 클래스 불균형에 따는 다양한 데이터 재샘플링, 재가중치 조절, 손실함수의 변경, 표현 학습과 클래스 구분의 두 단계 분리 방법 등 다양한 방법을 적용하였으며, 추가적으로 커리큘럼 러닝 방법, 자기 스페이스 학습 방법 등을 Bidirectional LSTM Attention, Convolutional Recurrent Neural Network, Multi-Head Attention, Bidirectional Temporal Convolution Network, Convolution Neural Network 등 총 5가지 네트워크 모델을 통하여 비교하고, 모터 소리 구분에 최적의 구성을 찾을 수 있었다.

• Composites Research
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• 제17권1호
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• pp.1-9
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• 2004

본 연구에서는 타격음을 이용한 비파괴 검사법을 제안하였다. 제안된 방법(tapping sound analysis)은 건강한 구조물과 손상된 구조물의 타격음의 차이를 분석하여 구조물의 손상 유무를 판단하는 방법이다. 타격음의 직접적인 비교는 비효율적이므로 타격음으로부터 특성을 추출하기 위해 wavelet packet transform에 기반한 특성추출법을 제안하였다. 또한 추출된 특성 자료를 바탕으로 손상의 유무를 판단하는 지표로서 특성 지수를 정의하였다. 제안된 방법의 타당성을 밝히기 위해 실험적인 검증을 수행하였다. 복합재료를 이용하여 건강한 구조물과 손상된 구조물을 제작하고 타격음을 측정하였다. 제안된 손상 판단 기법을 이용한 결과로부터 특성 지수에 의한 손상 판단의 타당성을 밝혔다.

• International Journal of Automotive Technology
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• 제7권1호
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• pp.43-49
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• 2006

In this paper, an index for the evaluation of a vehicle intake booming noise and intake sound quality were developed through a correlation analysis and a multiple factor regression analysis of objective measurement and subjective evaluation data. At first, an intake orifice noise was measured at the wide-open throttle test condition. And then, an acoustic transfer function between intake orifice noise and interior noise at the steady state condition was estimated. Simultaneously, subjective evaluation was carried out with a 10-scale score by 8 intake noise and vibration expert evaluators. Next, the correlation analysis between the psychoacoustic parameters derived from the measured data and the subjective evaluation was performed. The most critical factor was determined and the corresponding index for intake booming noise and sound quality are obtained from the multiple factor regression method. And, the optimal design of intake system was studied using the booming noise and the sound quality evaluation index for expectation performance of intake system. Conclusively, the optimal designing parameters of intake system from noise level and sound quality whose point of view were extracted by adapting comparative weighting between the booming noise and sound quality evaluation index, which optimized the process. These work could be represented guideline to system engineers, designers and test engineers about optimization procedure of system performance by considering both of noise level and sound quality.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.43-43
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• 2010

Presently, there is the dilemma of uncertainty with respect to the evaluation of sound and vibration based on the fact that there is obviously no agreement upon appropriate methods to measure the "truth" concerning the acceptance of sound and vibration. To evaluate properly physical and perception data in sound and vibration it is necessary to implement new methods and innovative approaches to understand the input of human response in sound design. Fortunately, an elaborate dialogue of the usefulness and applicability of those approaches is in progress. Moreover, the need of using and combining perception and physical data in order to comprehend the process of human perception and evaluation sufficiently is widely accepted. However, still the question remains how the goal of an adequate combination can be achieved. Clearly, themultidimensional human perception cannot be easily reduced to singular numbers. Moreover, factors, among others the meaning of the sound, the composition of the diverse sound sources, the listener's attitude, expectations and experiences, are significant parameters which have to be considered to comprehend the different perceptions and evaluations with regard to specific stimuli. Taking under consideration the physical, psychological, and cognitive dimensions as well as the integration of aspects of design require partially various new approaches. While binaural measurement and analysis technologies and psycho-acoustics are well established as they are proved to be valuable auxiliary tools; it has not been achieved to develop generally acceptable measurement units concerning sound quality. Consequently, there is a need for new approaches and methods which make it possible to comprehend sufficiently the process of perception and evaluation. Going with people's mind will be one solution for the future; thisconcept will be introduced based on the development in sound design.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.701-705
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• 2007

The equipment noise of machine room that generates at the building where human-being is living, is becoming to an object of strong civil appeal, and because it influences to the residential space through the floor or wall, its damage is very serious level. Accordingly, while an efficient forming of the sound insulating measures is earnest, as most of the transmission loss data was the material measured in laboratory, in case when it was applied to the job site, due to the precision difference of constructing work and the influence of detoured transmitting sound, the case of disaccord is the most. Therefore, this thesis has intended to present a fundamental data for an efficient establishment of sound insulation measure, by means of comparison analysis with the existing transmission loss data, after measurement of the transmission loss on the object of various walls, at the construction equipment machinery room.

• 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.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.184-189
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• 2008

본 연구는 기존에 저장되어 있는 응원이나 입력되는 사운드 데이터를 사용하여 게임 플레이상에 지형을 생성함으로서 사운드의 적극적인 황용을 도모하고 렌더링되는 화면과 입출력되는 오디오 간의 동기화를 통해 사용자들에게 공감각적인 상호작용을 제공한다. 사용자가 직접 사운드를 발생시키거나 원하는 음원을 입력하면 그 입력받은 사운드 진폭 데이터를 푸리에 변환하여 주파수 데이터로 변환하고 취득한 데이터로 분석 및 재가공하여 시간에 따라 변화하는 3차원 지형을 만든다. 지형이 생성될 때는 여러 가지 보간 처리를 통하여 에이전트들과 오브젝트들이 활동 가능하도록 지형을 보정하며, 확장 역시 용이하도록 디자인한다.

• 한국음향학회지
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• 제35권2호
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• pp.143-148
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• 2016

깊은 신경망은 데이터의 특성을 효과적으로 나타낼 수 있는 방법으로 최근 많은 응용 분야에서 활용되고 있다. 하지만, 제한적인 양의 데이터베이스는 깊은 신경망을 훈련하는 과정에서 과적합 문제를 야기할 수 있다. 본 논문에서는 풍부한 양의 음성 혹은 음악 데이터를 이용한 전이학습을 통해 제한적인 양의 사운드 이벤트에 대한 깊은 신경망을 효과적으로 훈련하는 방법을 제안한다. 일련의 실험을 통해 제안하는 방법이 적은 양의 사운드 이벤트 데이터만으로 훈련된 깊은 신경망에 비해 현저한 성능 향상이 있음을 확인하였다.

• 대한기계학회논문집
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• 제17권10호
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• pp.2426-2436
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• 1993

Vibration characteristics of a tire play an important role to judge a ride conformability and sound quality for a passenger car. In this study, the experimental investigation for the sound radiation of a radial tire has been examined. Based on the sound intensity techniques, the sound pressure field and the sound radiation are measured. It turns out that air pressure in tire, tread patterns, and aspect ratio of the tire govern the sound radiation characteristics. Then a numerical analysis for the tire element is conducted. During analysis, the tire element is modelled as an elastic ring. The comparison shows that the numerical output correlates to the experimental data.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.719-723
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• 2002

The purpose of this study is to suggest the correlation of single-number ratings for sound insulation by floor impact. As a assessment method of impact sound insulation. we selected the IIC contour of ISO, A weighted sound level. Inverse A-weighting curve and L-Index of japanese industrial standard. And we estimated the single-number ratings by application the measured data of impact sound level to each method. The results showed that the coefficients of determination between each two single-number ratings were very high (more than 0.9169). And In the condition of same assessment method, the coefficient of determination for light-weight impact sound was higher than that for heavy-weight impact sound.