• 항공우주시스템공학회지
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• 제14권spc호
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• pp.39-48
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• 2020

본 논문에서는 풍동 실험을 통해 측정한 소음 결과를 활용하여 실제 비행하는 기체에서 발생되는 소음수준을 예측하고 비행시험을 통해 검증하는 과정을 다루었다. 항공기의 환경소음 평가를 위해서는 일반적으로 국제민간항공기구(이하 ICAO)에서 규정한 절차에 따라 소음시험 및 평가를 수행하게 된다. 본 논문에서는 고정익 및 회전익(멀티콥터)의 특징을 모두 가지고 있는 복합형 기체에 적용이 가능한 환경 소음평가 방안과 실험을 통해 검증한 결과를 제시하였다. 고정익과 회전익 소형 무인기를 활용하여 풍동실험에서 측정한 소음시험 결과를 실제 비행 시험결과로 시뮬레이션 하는 과정을 제시하였다. 또한, ICAO에서 제시하는 비행 운용조건 및 소음 측정 방법을 고려하여 풍동실험을 통한 결과와 실 기체 비행시험을 모두 수행하여 항공기 소음인증을 위한 실효감각소음레벨(EPNL)을 예측 및 고찰하였다.

• 대한환경공학회지
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• 제31권12호
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• pp.1123-1128
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• 2009

치과병원에서 가동되는 기기소음이 환자들에게 피해를 줄 것으로 예상되어 치료시(스케일링, 치아제거) 및 비치료시(기기만 가동) 소음특성(소음도, 주파수 특성)을 측정하여 PSIL, NR과 같은 평가방법으로 분석하고 환자들의 기기소음에 대한 반응을 설문조사를 실시하였다. 치료기기로부터 1 m 떨어진 거리에서 측정한 소음도의 범위는 67.7~78.3 dB(A)로 4 k (Hz) 이상의 고주파성분을 나타내고 있으며 응답자의 대부분이 소음에 민감한 반응(기분이 거슬리거나, 병원방문을 망설임, 소름이 돋움, 깜짝 놀람)을 보이는 것으로 조사되었다. PSIL에 의한 소음 평가 및 설문조사 결과 환자와 치과종사자의 대화에는 문제가 없는 것으로 평가되었으나 NR곡선에 의한 평가 결과 NRN에 의한 각 실의 소음기준(ISO) 중 작업장의 소음기준(NRN 60~70 dB(A))을 훨씬 초과하는 수준이었다. 병원을 방문하는 환자들의 소음공포증을 해소시키기 위하여 방음보호구 제공, 저소음 저진동 장비의 선택, 마스킹 효과 등의 다양한 대책을 수립 제공하면 치과의료서비스 질을 개선하고 치과병원 경쟁력을 향상시킬 수 있을 것이다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2003년도 정기총회 및 추계학술대회
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• pp.95-100
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• 2003

The purpose of this study is to evaluate the noise environment of one-room type multi-family housing around the campus. The field measurements on equivalent noise level of indoor and outdoor were carried out in 6 subject house units during the 26th${\sim}$28th of November 2002. The results are as follows. 1) Outdoor noise levels of 6 subject buildings were distributed 52.8${\sim}$65.3dB(A) and were inappropriate to the standard for environmental noise, 55dB(A). 2) Indoor noise level of 6 subject house units were measured 27.5${\sim}$63.5dB(A). These values were higher than the indoor noise standard (40dB(A)) except subject house D(average 37.6dB(A)). 3) It was found that the differences of indoor noise levels between subject house units were caused by resident's living factor, characteristics of window, and existence of balcony.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1465-1468
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• 2006

Railway is superior to the other land transportation systems in aspects of environmental problems. Environmental problems are not considered during a preliminary feasibility study. Investment for railway is low because of low B/C(benefit/cost)ratio in the economical efficiency analysis during the preliminary feasibility study. The body of this paper studies the railway noise which can reflect environmental problems an assessment of environmental impact. The body of this paper studies the presumption of The Benefit Cost of railroad noise arresting it will be able to reflect the evaluation environmental matter of the effect which it gives to an environment.

• 한국산업보건학회지
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• 제15권3호
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• pp.202-212
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• 2005

This study was aimed at rating the existing work environment noise components and alternatives in point of worker's view. To answer the purpose, AHP(Analytic Hierarchy Process) method is adopted in this research. Based on the AHP method, this research abstracts a mathematically rigorous noise components and alternative's weights and proven process for priority and decision-making. By reconstructing complex hearing conservation programs to a series of pair-wise comparisons, and then synthesizing the results, this study not only helps establishments of noise countermeasure, but also provides a clear rationale for noise alternatives. The result of this study is summarized as follows; 1) Job satisfaction index and noise identification index are 63, 56 respectively. 2) Noise level(15.7%), frequency(14.1%) and directivity(13.6%) are main reasons in worker's ground. 3) There are some difference between the estimation of worker's identification and that of work sites. 4) Low noise machine(14.7%), enclosure(13.2%) and shielding(9.6%) are chosen for noise protection method by workers. 5) Noise environment improvement should be focused on noise source rather than personal protection. 6) By the AHP method, noise source countermeasure have a key role at work environments.

• 환경정책연구
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• 제9권3호
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• pp.29-46
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• 2010

소음지도를 활용하여 개발계획의 수립단계에서 환경소음을 사전에 예방하기 위한 방안을 제안하였으며 도시기본계획의 전략환경평가와 도시개발사업의 환경영향평가를 대상으로 하였다. 도시기본계획의 전략환경평가에서는 도시지역의 개발계획내용과 소음지도 제작결과를 상호 비교 검토하여 환경소음의 영향을 고려한 계획의 타당성과 입지의 적정성을 검토하고 도시지역의 소음현황과 개발계획의 시행으로 인한 소음영향을 종합적으로 평가하여 그에 따른 장기적인 저감대책을 수립하는 것을 포함한다. 도시개발사업의 환경영향평가에서는 소음지도를 통한 개발지역 주변의 소음현황 파악, 환경소음의 현황과 개발사업으로 인한 소음영향에 대한 종합적인 평가, 다양한 소음저감방안 적용에 따른 소음지도 제작결과의 비교 검토를 통한 최적의 대책 마련 등을 포함한 소음지도 활용방안을 제안하였다.

• 한국환경과학회지
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• 제25권10호
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• pp.1407-1415
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• 2016

In this study, we investigated the relationship between noise reduction and the community structure of nine groups of typical plant communities as well as the reduction in noise at different frequencies. The semantic differential method was adopted to explore the perception of noise reduction. The results indicated that there was a significantly positive correlation between noise reduction and coverage, a significantly negative correlation between noise reduction and bifurcate height, and a negative correlation between noise reduction and bare rate. However, there was no significant correlation between noise reduction and height, diameter at breast height, or crown width. The reduction of middle-frequency noise was better than that of low- and high-frequency noise. The indicators "quiet" and "calm" showed that plant communities could reduce the noise perceived by humans. However, overly dense woodland caused nervousness, fear, depression, and other negative effects. Relatively open environments and those with large forest gaps obtained the highest evaluation.

• 한국소음진동공학회논문집
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• 제18권1호
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• pp.57-60
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• 2008

Since human listening is very sensitive to sound, for evaluating of a sound quality is required. Therefore, in the analysis for each situation, the sound evaluation is composed with sound quality factor. My researchers spends their effort to make a more reliable and more accurate of sound in term of sound quality index for various system noise. 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 highly dependent on jury test and have many difficulties due to various environmental factors. So, to reduce jury test weight. we suggested a new method using Mahalanobis distance for SQ evaluation. Threrefore, in this study Mahalanobis distance for the vehicle interior noise was derived using the objective SQ except jury test. Finnaly, the results of the SQ evaluation was analyzed discrimination between reference and abnormal group.

• KIEAE Journal
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• 제8권1호
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• pp.31-36
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• 2008

For the comfortable housing life, comfortable and pleasant urban environment should be created for the people living in house and in city. There are lots of environmental conditions in city affecting house and life. Also most of all the noise pollution have been become major factor that makes people's life uncomfortable. Recently soundscape researches have been performed to create comfortable urban environment and various studies on the evaluation of urban environmental sounds are now undergoing. This study aimed to analyse the subjective characteristics through the subjective evaluation to the sounds measured with physical parameters and eventually to find out alternative evaluation method for urban environmental sounds. Adjectives applied to previous studies were used for the subjective evaluation and sound sources recorded in specific places were presented with picture at the same time. As a result, new physical parameters such as Lmax, Unbiased Annoyance, G, N and EmT have a feasibility to evaluation of urban environment sounds in terms of acoustic comfort.

• 환경영향평가
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• 제18권3호
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• pp.143-150
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• 2009

The present study investigates the effects of the flight paths of military aircraft on noise map and its WECPNL(Weighted Equivalent Continuous Perceived Noise Level) distribution. Aircraft noise modeling and simulation have been performed on a Korean military air base by means of INM(Integrated Noise Model) with the input data of airfield location, aircraft specifications, flight paths and aircraft's operation schedules. The result of noise modelling has been verified in comparison with the result of measured noise level. The flight path of military aircraft, as the key parameter of the present study, was modeled by combining takeoff, overfly, approach and touch-and-go modes. The present INM simulations have been conducted for various flight path cases with different takeoff, approach modes and overfly modes. The simulation results showed that the change of flight path can remarkably affect the noise influence region and the WECPNL distribution around the airfield.