• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1317-1320
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• 2006

This study compared the floor impact sound level of rectangular receiving room type to differed receiving room types to analyze effect of room mode. The floor impact sound level of master room were higher than the level of living room which resulted from room mode. The result showed that the level of low frequency bandwidth in the location varied with receiving room types were lower than general measuring point of rectangular receiving room.

• 동력기계공학회지
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• 제3권3호
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• pp.97-103
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• 1999

As the noise of ship engine room is too loud, the engineer who works in a ship engine-room has the trouble of hearing. In this paper deals the investigation of the noise of ship engine room and cabins with the internationally allowable noise exposure level and noise exposure time. Recently, the problem of engine-room noise is more serious because of shipowner wants to make small number and larger size of cylinder. Therefore, engineers work in a ship engine-room for a long time have the trouble of hearing when they are exposed the high noise level. In this study, two kinds of vessels were used to investigate the noise of engine room, engine-control room, bridge, offices and cabins. As criteria of sound levels, A-weighted sound pressure level and octave band pressure level were used.

• 한국해양공학회지
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• 제21권2호
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• pp.60-66
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• 2007

The first Korean cold room facility for ice mechanics experiments was assembled in 2004. Since then, the $4m{\times}6m$ cold room facility has been used, extensively under various environmental and loading conditions. After reviewing published references on cold room testing methods and also by trial and error, the standard procedures for testing and preparing laboratory ice material were established for the measurement of basic ice properties. In this paper, laboratory experimental techniques with the cold room facility and standard procedures established for ice material properties are introduced. Test specimens include laboratory-grown fresh water ice and frozen soils. Tests are carried out for unconfined compressive strength. Preparation and dimension of the specimen are the most important issues arising in cold room tests. The details of specimen preparation, testing procedure and strength test results are also discussed.

• 한국화재소방학회논문지
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• 제18권4호
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• pp.78-85
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• 2004

본 연구에서 Clean Room 재해사례를 분석하였고, Factory Mutual Property Loss Prevention Data Sheets(FM), Industrial Risk Insurers(IRI), NFPA Code 등의 Clean Room 설계 주요 방화기준에 대하여 비교 분석을 하였다. 그리고 화재시뮬레이션을 통한 위험성 평가를 통해서 화재 시 공조설비의 작동으로 인한 연기산란 현상으로 Clean Room 내의 피해규모가 상상을 초월하는 결과를 얻을 수 있었으며, 또한 스프링클러설비의 작동으로 열온도가 더 낮아지고, 연기의 확산속도를 더 줄여줄 수 있는 것으로 분석되었다. 따라서, Clean Room내의 화재 시 화재감지기에 의해 공조설비를 정지시키고, 스프링클러설비를 설치하는 것이 안전성을 확보하는데 중요한 요소임을 유추하였다. 그러므로 본 연구에서 Clean Room 에 대한 안전성을 확보하는데 기여하고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.23-27
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• 2007

Many trials have been used to model room impulse responses, all attempting to provide efficient representations of room acoustics. The traditional model designs for room impulse response seem to fail in accuracy, controllability, or computational efficiency. In time domain, a room impulse response is generally considered as the combination of three parts having different acoustic characteristics, initial time delay, early reflection, and late reverberation. This paper introduces new learning hybrid model for the room impulse response. In this proposed model, those three parts are modeled using different models with learning algorithms that determine the length or boundary of each model in the hybrid model. By the simulation with measured room impulse responses, it was examined that the performance of proposed model shows the best efficiency in views of both the parameter numbers and modeling error.

• 한국소음진동공학회논문집
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• 제18권3호
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• pp.361-367
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• 2008

Many trials have been used to model room impulse responses, all attempting to provide efficient representations of room acoustics. The traditional model designs for room impulse response seem to fail in accuracy, controllability, or computational efficiency. In the time domain, room impulse responses are generally considered as combination of the three Parts having different acoustic characteristics, initial time delay, early reflection, and late reverberation. This paper introduces new learning hybrid model for room impulse responses. In this proposed model, those three parts are modeled using different models with learning algorithms that determine the boundary of each model in the hybrid model. By the simulation with measured room impulse responses, the performance of proposed model shows the best efficiency in views of computational burden and modeling error.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.839-843
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• 2008

Receiving room's floor impact sound level is been influenced to various factor of slab thickness, room size, structure etc. This study examined the noise of upper part slab and room mode in receiving room to be importance factor that influence in receiving room level among this factors. According to this study, vibration mode in slab and room mode are concentrated on frequency that is high level relatively. This causes bad effect in floor impact sound level. Therefore, method to reduce floor impact sound level is to change vibration mode using slab upper part's resilient material or reduce room mode in receiving room.

• 한국소음진동공학회논문집
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• 제25권4호
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• pp.291-298
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• 2015

In this study, the reverberation time of apartment living room was measured and distribution of the reverberation time was analyzed. In addition, sound field characteristics of mock-up test room similar with living room and timber structured bedroom was investigated with addition of furniture and sound absorption material. Average reverberation time of unfurnished apartment unit was 1.11 s, and reverberation time in 630 Hz~2000 Hz bands were longer than 1.2 s. It was found that from the field measurement results, reverberation time characteristic of furnished apartment living room was uniform in most of frequency bands. Averaged reverberation time of furnished living room was 0.48 s and the reverberation time of bedroom was 0.44 s. Standardized sound pressure level correction values were calculated from the average reverberation time of furnished and unfurnished apartment units. The correction value of unfurnished living room was −3.4 dB and that of furnished living room was 0.2 dB. Measured reverberation time of furnished and unfurnished apartment units indicated that reference reverberation time; 0.5 s, in KS and ISO standards is reasonable also in Korean residential environment.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1951-1956
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• 2019

As a part of the preliminary decommissioning plan of KEPCO-NF fuel fabrication facility, DCGLs of three target radionuclides, ²³⁴U, ²³⁵U, and ²³⁸U, were derived using RESRAD-BUILD code and contaminated areas of the facility were classified based on contamination levels from the derived DCGLs. From code simulations, one-room modeling results showed that the grinding room in building #2 was the most restrictive (DCGL_gross = 10493.01 Bq/㎡). The DCGL_gross results in contaminated areas from one-room modeling were slightly more conservative than three-room modeling. Prior to the code simulation, field survey and measurements conducted by each survey unit. For a conservative approach, the most restrictive DCGL_gross in each survey unit was taken as a reference to classify the contaminated areas of the facility. Accordingly, seven rooms and 37 rooms in the nuclear-fuel buildings were classified as Class 1 and Class 2, respectively. As expected, fuel material handling and processing rooms such as the grinding room, sintering room, compressing room, and powder collecting room were included in the Class 1 area.

• 대한설비관리학회지
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• 제23권4호
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• pp.51-56
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• 2018

Computed tomography (CT) scan room in the department of radiology is very necessary to maintain pleasant and proper illuminance to relieve fatigue and inconvenience because it affects the work environment to the radiologist. Accordingly, this paper describes the method for measurement of illuminance that exposed to an environmental elements in a CT scan room of the hospital. Therefore, the purpose of this paper is to propose an optimal environment of CT scan room based on the measurement of illuminance. In addition, the 5 point method by KS C7612 was applied to measure the illuminance with illuminometer (Unfors xi light probe) in the CT scan room. In result of this paper, minimum value and maximum value of illuminance in the CT scan room was measured 212.7 lux and 354.8 lux, respectively. The illuminance of CT scan room was lower than KS A 3011. Finally, the work environment in CT scan room should provide higher illuminance for the comfortable environment of radiologists and patients.