• 한국소음진동공학회논문집
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• 제15권5호
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• pp.550-557
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• 2005

Korean 'Law of Aviation' and 'Test Method of Measuring Noise and Vibration' designate to use WECPNL metric based on $L_{max}$ measurement for the accessment of aircraft noise in Korea. However, time duration of noise event can not be considered in $L_{max}$ metric in principle, compensation on the duration has been utilized. A study was done recently to evaluate appropriate duration compensation for the accessment of military aircraft noise under current metric of WECPNL and $L_{max}$. This study was carried out to evaluate what metric is the most appropriate to express aircraft noise including time duration of single noise event, computing and comparing noise exposure with 1 second noise measurement data of military aircraft in $L_{max}$, $L_{Aeq,\;T}$ and SEL. This study shows SEL is the most appropriate noise metric for the evaluation of noise exposure with time duration such as aircraft noise without compensation. It is suggested to use SEL noise metric instead of $L_{max}$ noise metric with duration compensation for the aircraft noise accessment either military aircraft or civilian aircraft.

• 한국소음진동공학회논문집
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• 제16권5호
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• pp.503-513
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• 2006

The duration time of aircraft noise event is also an important factor for the evaluation of civil aircraft noise, which is considered as a notable characteristic of military aircraft noise. SEL is proved as a suitable noise metric for the measuring military aircraft noise of various flight pattern considering the duration time of noise event. This study reviews whether SEL is a suitable for measuring civil aircraft noise and study shows SEL is fairly compensating the duration time of civil aircraft noise event for the evaluation of aircraft noise. Noise metric for the evaluation aircraft noise based on SEL is more appropriate than based on $L_{MAX}$ for compensating duration time of noise event either military aircraft or civil aircraft. In this reason, current formula of WECPNL based on energy average of measured $L_{MAX}$ for the evaluation of aircraft noise impact in 'Test Method of Noise and Vibration of Korea' is recommended to be amended to formula of WECPNL based on energy average of measured SEL considering compensation of noise event duration time, if WECPNL is not based on measured EPNL, a metric compensating duration time.

• 한국자동차공학회논문집
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• 제23권2호
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• pp.185-190
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• 2015

The purpose of this study is developing the quantify the seat belt pulling Noise index and evaluation method. This paper presents the objective method to evaluate the emotional feeling about the pulling Noise of the seat belt. The physical quantification is required to objectively evaluate the emotional feeling of the pulling Noise. This is called the "Noise metric." The Noise metric is should correlated to the subjective rating of the pulling Noise. The pulling Noise index is developed throughout the linear regression of the Noise metric and the subjective rating. The developed index is used for the objective evaluation of the emotional feeling about the pulling Noise of a seat belt throughout the modification of seat belt components.

• 한국산업정보학회논문지
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• 제2권2호
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• pp.219-228
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• 1997

The Fano metric is the maximum likelihood decoding choice for convlutional code for binary symmetric channel. The Fano metric assumes that it has previous knowledge of channel error probability. However, the bit errors in real channel occur in bursts and the channel error probability can not be known exactly. Thus, the Fano metric is not the maximum likelihood choice for bursty-noise channel. In this paper universal metri which dose not require the previous knowlege of the channel transition probability is used for sequential decoding. It is shown that the complexity of the universal is much less than that of the Fano metric bursty-noise channel, since it is estimated on a branch by branch basis.

• 한국소음진동공학회논문집
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• 제20권1호
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• pp.66-73
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• 2010

Vehicles experience the impact due to harsh road conditions. Contact with a barrier on a road induces vehicles to vibrate, which brings about an impact sound. The attenuation of the impact sound is an important issue since passengers may complain about the impact noise. However, the perfect removal of impact noise is not possible as most of impact noise is caused by external conditions. It is thus necessary to make vehicles to possess more desirable sound quality characteristic of impact sound. More research is needed on objective attributes of impact sound; it is not a simple matter since impact noise is transient in nature and has a high level of sound at an instantaneous moment. A new objective attribute of impact noise is designed by using wavelet transform. Wavelet transform is appropriate for the analysis of transient signals such as impact noise. The usefulness of new objective attribute, which is a sound metric, is examined by comparison with the mean subjective rating for real impact noise of passenger cars. The new sound metric has better correlation with the mean subjective rating than already existing sound metrics

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.526-527
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• 2014

• 한국소음진동공학회논문집
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• 제25권3호
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• pp.141-149
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• 2015

In this study, there is an investigation about the sound quality of automotive horn that attached to luxury sedans. In order to define a questionnaire of horn sound quality the factor analysis is conducted. Ten automotive horns are selected for this research and ten passenger cars(nine is luxury sedan and one economy class car). Luxury is used for the questionnaire as an attribute for the sound quality of car horn. The interior noises for ten test cars are recorded and used for the subjective analysis of car horn sound. In the paper, new sound metric for the car horn sound is presented. The new sound metric is used for the objective sound index for the prediction of subjective sound quality of car horn.

• 한국지능시스템학회논문지
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• 제14권5호
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• pp.583-586
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• 2004

고밀도의 저장기록장치 채널의 주요 신호검출 오류의 원인은 천이 지터잡음이다. 이러한 채널환경에서 최적의 신호검출기 구현을 위해서는 고도의 복잡도가 요구되는데 이는 지터잡음이 신호와 상관관계가 있고 잡음간에도 상관관계가 존재하기 때문이다. 본 논문에서는 계산량과 하드웨어 복잡도 관점에서 효율적인 두 가지 종류의 신호검출기에 대해서 설명한다. 이는 전통적인 비터비 복호기의 가지값을 변화시킨 형태이며 같은 이진데이터 값의 반복을 제한하는 부호와 함께 결합하여 일반적인 PR 채널에 적용된다 기존의 비터비 알고리즘의 복잡도와 비교하면 비터비 트렐리스에서 각각의 가지값을 계산할 때 추가적으로 하나의 곱셈기 혹은 덧셈기의 증가가 요구된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.421-424
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• 2007

Currently domestic criteria for the aircraft noise is being adapted WECPNL(weighted equivalent continuous perceived noise level), while internationally preferred method is $L_{dn}$ which is based on from $L_{eq}$ and can also evaluate environmental noise. WECPNL used in domestic as an evaluation metric is only for the aircraft noise. It is, therefore, not adequate for the evaluation of residents' injury, moreover, it is very difficult to measure the aircraft noise by WECPNL due to the complicated calculating procedures as long as automatic measuring system is not used. Accordingly, this study aims to propose alternative evaluation metric for the aircraft noise. To achieve this purpose, WECPNL, $L_{eq}$, $L_{dn}$, other metrics and criteria were compared and analyzed.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1997년도 추계학술대회 발표논문집:21세기를 향한 정보통신 기술의 전망
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• pp.435-449
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• 1997

In this paper, a new metric, universal metric, is Proposed for sequential decoding of convolutional decoding. The complexity of Fano metric for Fano's sequential decoding algorithm is compared with that of the proposed universal metric. Since the Fano metric assumes that it has previous knowledge of channel transition probability, the complexity of Fano metric increases as the assumed channel error probability does not coincide with the true channel error probability. However, the universal metric dose not require the previous knowledge of the channel transition probability since it is estimated on a branch by branch basis. It is shown that the complexity of universal metric is much less than that of the Fano metric for bursty noisy channel.