• 한국소음진동공학회논문집
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• 제15권8호
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• pp.945-953
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• 2005

The purpose of this paper is to develop a linear regression model for the sound quality index of vehicle Interior noise. For this, objective measurement data of the vehicles driving in acceleration was measured. On the basis of analysis, psychoacoustic parameters were extracted and subjective evaluation was performed by noise and vibration expert evaluators. For the subjective evaluation, the paired comparisons and the semantic differential methods were used to evaluate sound quality of vehicle interior noise. By the paired comparison which evaluate two pairs of vehicle interior noise, the preference was estimated. With the semantic differential and the factor analysis, it was evaluated words of two pairs which expressed appropriately the sense of evaluator about noise source. Therefore the characteristics of the sound qualify for the vehicle were differentiated. From the results of both the correlation analysis and the multiple factor regression analysis, the sound quality evaluation model for the sense of human hearing was derived and indexed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.311-317
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• 2007

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• 한국소음진동공학회논문집
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• 제18권4호
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• pp.393-399
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• 2008

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.483-488
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• 2013

The psychoacoustic quality of ABS is now considered more important than before as the focus of recent ABS function is expanded to basic function from typical emergency function. Thus, the automotive parts manufacturing companies are actively working to improve NVH (Noise, Vibration, and Harshness) in ABS module. In terms of time, test place, and cost, however, it is very inefficient to have all the operating noise validation test in real vehicle configuration especially for partially improved ABS module. To contribute to reducing the development period and to grasping the improvements faster, this research presents the study of a correlation to predict ABS operating noise inside vehicle via HILS rig test. The regression equation in this paper was statistically drawn from using Minitab S/W, and based on that equation, the noise spectrum of vehicle interior was analogized.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2467-2470
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• 2003

This paper presents a new structure of MPEG-4 AAC encoder. The proposed encoder directly shapes quantization noise distribution according to the energy distribution curve and thereafter performs adjustment of the offset level of the noise distribution to meet the given bit rate. The direct noise shaping and the bit rate matching scheme of the proposed encoder algorithm significantly alleviate the problem of conventional encoder's processing burden related with the employment of the precise psychoacoustic model and iteration intensive quantizer. The encoder algorithm is implemented on ARM processor with fixed-feint arithmetic operations. The audio quality of the implemented system is observed comparable to those of commercially available encoders, white the complexity of the implementation is drastically reduced in comparison to the conventional encoder systems.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.116-121
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• 2013

Panaroma Sun roof's sun shade motor elicits two major sounds when operating: the tonal sound and the white noises. Generally, the sound related to the sharpness contributes the most to the quality of motors' tonal sound. The primary purpose of this study was to set the loudness of the motor's objective tonal sound utilizing the masking effect by its white noises. To conduct this study, the sound made by the operating sun shade motor was categorized into two different subsets of masker and test tone to examine the masking threshold. Also, the shifts of masking threshold were observed with the varying masker loudness.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.513-518
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• 2013

The purpose of vehicle horn sound is for warning to pedestrians. In the past, the main development factor is to match the regulation level. But nowadays perceived quality is more important than level itself. In this study, we measure variety horn sound and evaluate its signals through the jury evaluation aimed at making horn sound quality index. Each contribution of the noise path for sound quality is identified and the target values and methods for implementing the luxurious horn sound are suggested. Finally, we developed, horn component and improve horn mounting condition for luxurious horn sound.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.489-494
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• 2000

제품과 사용자간에 필연적으로 존재하는 소리를 쾌적하게 하기 위한 연구로서 자연음 6종과 소음 6종의 음압(dB)이 비슷하도록 조절하였을 때 소리의 어떠한 물리적 특성이 긍/부정감성에 주된 영향을 미치는지를 파악하기 위하여 남/녀 각각 35명씩의 대학생들에게 7점척도의 8가지 형용사 쌍을 이용한 음질평가 청감실험을 한 결과 물소리를 포함한 자연음은 소음보다 대체로 긍정감성이 높게 평가되었고 긍정감성과 심리음향인자와의 상관성은 Loudness의 -0.37을 비롯하여 "-"상관성을, Unbiased annoyance와 심리음향인자들과의 상관성은 Loudness의 0.92를 비롯한 "+" 상관성을 각각 갖었으며 여자는 남자보다 긍/부정감성에 더욱 예민하게 반응하는 것으로 나타났다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.629-633
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• 2005

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. In previous study, we have developed to verify identification of source for the vehicle HVAC system through multiple-dimensional spectral analysis. Also we carried out objective assessments on the vehicle HVAC noises and subjective assessments have been already performed with 30 subjects. In this study, the linear regression models were obtained for the subjective evaluation and the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Appropriation of regression model is necessary to $R^2$ value and F-value. And testing for regression model is necessary to Independence, Homoscedesticity and Normality. Also we selected optimum layout of damping material using Taguchi method. As a result of application, sound quality is improved by more quiet, powerful, expensive, smooth.

• 한국음향학회지
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• 제25권3호
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• pp.129-136
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• 2006

소음에 대한 인간의 심리적 인지는 소음의 여러 가지 물리적 요인에 의하여 영향을 받는다. 그러나 현재의 환경소음 평가는 A 가중치 등가 소음 수준을 기준으로 평가되고 있으며 인간의 다양한 감성적 요인을 반영하지 못하고 있다. 따라서 본 연구에서는 환경소음 평가를 위하여 환경소음원 43개에 대하여 주관평가와 통계적 분석방법을 사용하여 인간의 감성에 영향을 주는 음질인자 (Sound quality factor)를 분석하였다. 분석방법은 먼저 다양한 환경소음원에 대한 음질물리량 (Sound quality metrics)을 분석하여 음원을 분류하였으며 분류된 음원의 주된 음질 물리량을 고찰하였다. 그리고 쌍대비교법 (Paired comparisons method)과 어의분별척도법 (Semantic differential method)을 사용하여 주관 평가를 실시하고 음질의 요인을 분석하였으며 물리량과의 관계를 규명하였다. 마지막으로 요인에 대한 물리량의 기여도를 분석함으로써 환경소음의 감성적 인지에 대한 기초 물리량을 설정하였다.