• 한국분무공학회지
• /
• 제21권3호
• /
• pp.162-169
• /
• 2016

When we construct a road near an apartment complex, we consider a soundproof wall. To make residential places quieter, we may consider a soundproof road tunnel. Such a tunnel, however, would become highly concentrated with soot from vehicles whenever a traffic jam might occur. To create an optimum design, this study utilizes the PHOENICS-VR software. The work considers three cases: (1) no openings (2) openings at 30m intervals, and (3) openings at 60m intervals on the upper side of the tunnel. The study finds that in the second case shows CO concentration distributions were 15% less than those without openings. And the CO concentration distributions of the second and third cases are almost the same. The findings suggest that we should make the soundproof tunnel to reduce construction fees.

• International Journal of Railway
• /
• 제6권3호
• /
• pp.125-130
• /
• 2013

Most of the test methods used for determining the acoustic performance of the noise barriers in Korean standards address the sound-proof panels but refer to noise barriers as a whole system or their in-situ performances less. Many new types of trains with different operating speeds have been developed and produced, and civil appeals against railway noise are becoming quite extensive. Considering these latest changes of circumstances, it is necessary to investigate the current standards and specifications pertaining to railway noise barriers. In this paper, criteria for the measurements and evaluations of noise barriers and sound-proof panels are examined and experimental studies are introduced. In order to suggest more efficient methods for reasonable evaluations of the noise barriers, frequency spectrums of the noise source, the power of the actual railway vehicles, are investigated and introduced.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
• /
• pp.676-681
• /
• 1997

The purpose of this study is to evaluate the thermal Conductivity and Foolr Impact Sound of Polyurethane Concretes. The Polyurethane Concretes are prepared with various resin content, Fine and Coarse aggregates content, and its thickness, and tested for the Thermal Conductivity and Impact Sound. From the test results. the sound insulation grade of polyurethane concretes by the floor impact sound test on high frequency band is L-60, and its effect is considerable Polyurethane concretes have high degree of solidity compared with other heat shield materials, and its thermal conductivity is 0.05kcal/$mh^{\cire}C$. And it is suitable for sound proof floor materials.

• Architectural research
• /
• 제8권2호
• /
• pp.11-16
• /
• 2006

The purpose of this study is to scrutinize the effect of office layouts and ambient office sounds on the performance of office workers involved with a proof-reading test (simple task). Twenty subjects, who were professional researchers and computer programmers, were from three different office layouts: 1) Nine subjects from a combined office type with open meeting places and closed individual offices; 2) five from an open office with rectangular individual workstations, and 3) six from an open office with triangular individual workstations. Architects and consultants working in the field of office have reported from interviews and their own observations that occupants' satisfaction differs as their office layouts vary although the sizes are the same. This finding leads to the hypothesis of this experiment. Proof-reading test results were obtained from three different office layouts (combined office type, rectangular and triangular individual workstations in open offices) under two different sound conditions (quiet background sound and ambient sound of their own workplace) for 10 minutes. The test analysis shows the mean test score of subjects from the triangular individual workstations in open offices is significantly different from the mean test scores of subjects from the combined office type and the rectangular individual workstations in open offices.

• 한국환경생태학회지
• /
• 제12권1호
• /
• pp.78-90
• /
• 1998

본 연구는 1980년대 후반부터 조성된 5개 신도시 공동주택단지의 완충녹지를 대상으로 녹지의 형태와 식재기법, 효과 등을 분석하여 완충녹지 조성시 배식에 이용할 수 있는 자료 구축을 목적으로 하였다. 연구대상지 완충녹지의 형태는 마운딩형, 사면형, 펴연형이었으며 식재된 수종으로는 교목은 상록수 10종, 낙엽수 20종의 총 30종이었고 관목은 총 13종 이었으며 도시공원 등의 관상용수종과 차이가 없었고 식재는 단층적으로 한 상태였다. 완충녹지에 의해 소음완화 효과는 인정되었으나 7개 조사유형중 4유형에서는 공동주택단지의 소음 기준치(65dB) 이하의 완충효과를 보이지 못했다. 소음완화효과는 마운드형이 효과적이었다. 본 연구대상지는 식재밀도, 녹지용적계수는 완충녹지의 기능을 충족시키지 못하고 있으며 자연림과 비교했을 때 식재밀도가 매우 적었고 녹지용적계수도 기준 녹지에 비해 션격히 낮은 값을 나타내어 개선이 요구되었다. 완충녹지는 높이를 2m 이상으로 한 마운딩형으로 조성지역 인근 자연림의 식생구조를 모델로 하는 복층적 식재기법을 이요하여 조성하는 것이 바람직한 것으로 판단되었다.

• 한국지반환경공학회 논문집
• /
• 제12권3호
• /
• pp.27-35
• /
• 2011

본 연구는 터널발파에서 소음저감을 목적으로 설치되는 방음시설 개발을 위하여 현장에서 주로 사용되는 방음재와 물, 모래 등을 이용하여 각 재질에 따른 소음저감효과를 판단하였다. 최대 소음레벨과 주파수의 범위를 측정하여 방음재질별 소음감쇠도와 주주파수 대역의 음압레벨을 고찰하였다. 그리고, 방음재료 분석의 결과를 반영하여 물과 스펀지 등으로 채운 개량형 워터튜브 방음문과 기존 스펀지 부직포 등으로 채운 방음문을 축소 제작하여 화약을 사용하여 실대형 현장실험을 통한 검증을 하였다. 그 결과 물을 차음재료로 사용한 경우에 기존 방음문에 비해 약 10dB(A) 정도의 소음 저감효과를 나타내었다.

• 한국산학기술학회논문지
• /
• 제10권3호
• /
• pp.607-612
• /
• 2009

생태방음벽에 있어서 구조도 중요하지만, 식물종자의 발아와 생장율을 고려한 선택도 매우 중요하다. 재래종과 외래종 35종을 선발하여 온도 $24^{\circ}C$, 습도 60%, 그리고 12시간 주기로 낮과 밤을 조절하였고, 식생기반재로 일반토양과 유기물 토양의 비율을 6:4, 7:3, 8:2, 9:1로 하여 실험하였다. 실험한 종 중 8종은 2주 동안 발아하지 않았지만 그 외 나머지 종들은 시간차를 두고 모두 발아하였다. 가장 발아율이 좋은 종은 Perennial penant(92 %)이고 다음은 Brassica napus(86%), 그리고 Silene armeria(82 %) 순으로 나타났다. 본 연구에서는 발아한 종의 뿌리 및 줄기의 길이를 측정하여 분석하였다. 이번 연구에서 뿌리의 생장이 가장 좋은 3종 Perennial penant, Perennial sonata Rebolsentri가 생태방음벽 개발에 가장 적합한 종으로 사료된다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2001년도 춘계학술대회논문집
• /
• pp.1040-1044
• /
• 2001

This study is to propose an analyzing method of road traffic noise in apartment sites using computer simulation program. The evaluation method used in this study is to calculate "Site Equivalent Noise Level". It will be possible to set up effective sound proof system with calculation of "The Number of Houses Exceeding Standard Noise Level".

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
• /
• pp.575-581
• /
• 1998

The noise sources in the outdoor unit of RAC(Room Air Conditioner) are identified by the sound intensity method. The main noise sources are compressor noise and fluid noise which is caused by the fan, heat exchanger and shroud. First, the fluid noise is reduced through the design ol new fan and shroud with high flow rate and low noise, reduction of the system resistance by rearrangement of heat exchanger, and optimization of the complex parameter between the fan and shroud. Next, in order to reduce the compressor noise, the new shape of compressor mount and sound-proof material was applied. As a result, the overall noise was reduced by 4-5dB(A).

• 한국소음진동공학회논문집
• /
• 제20권11호
• /
• pp.1001-1008
• /
• 2010

The architectural, facility makes the housing environment more pleasant, while too much noise coming from machinery room is detrimental to the workers physically and mentally. Therefore, more sound insulation and sound proof policies are increasingly required. However, as the annoyance caused by facility noise is influenced by various human listening characteristics as well as physical characteristics such as sound pressure level, it requires subjective evaluation characteristics through acoustic-psychological approach. For this purpose, the facility noise in the machinery room was actually measured and analyzed in the field to understand physical characteristics, and the correlation between physical evaluation value and psychological response value through listening test. Further, this study aims at presenting the data to set the standards of 'Just noticeable difference' of the facility noise together with reasonable evaluation with psychological reaction, through the grading of facility noise using trend formula. In the result, 13 stages of physical properties were forecasted for each evaluation method, together with 'Just noticeable difference' using the grading of architectural facility noise.