• Analytical Science and Technology
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• v.19 no.6
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• pp.544-552
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• 2006

Emission tests were carried out to investigate the characteristics of concentration according to flooring sort using small chamber method. The target Volatile Organic Compounds (VOC) included 27 individual compounds of environmental concern, which were determined by adsorption sampling and thermal desorption coupled with GC/MS method and by DNPH cartridge/HPLC method. The emission factor of Total Volatile Organic Compounds (TVOC) and Formaldehyde (HCHO) was detected $0.3mg/m^2{\cdot}h$ and $0.2mg/m^2{\cdot}h$ respectively, and the floorings of 37 (9 PVC Tile, 10 PVC Sheet, 18 Flooring) were satisfied emission standard. TVOC emission factor appeared in order of concentration of PVC Sheet, PVC Tile, and floor flooring, while HCHO was detected very high emission factor (as $0.4mg/m^2{\cdot}h$) at floor flooring above PVC series (as $0.001mg/m^2{\cdot}h$).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.12
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• pp.1207-1215
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• 2008

Satellite generates a complex electromagnetic noise by conducted and radiated coupling effect of the various electrical instruments. This noise may cause serious problems on the satellite system. To minimize the electromagnetic coupling effects and maintain the system safety margin, system noise reduction technique should be applied from the beginning of the system design. The COMS system is evaluated by measuring the conducted noise on system electrical power leads at PSR(Power Supply Regulator) and verifying a 6 dB system safety margin under the complex noise environment with current injection. The radiated noise due to the complex transmit antenna configuration is evaluated by integrating all unit-level RE measurement results, and the RF compatibility between spacecraft and launch vehicle is analyzed with the above estimations. This paper describes the COMS EMC compatibility analysis with respect to each unit level EMC test results, and RF compatibility analysis between spacecraft and launch vehicle. The analyzed results will be reflected on FM(Flight Model) EMC test.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.249-252
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• 2006

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.460-465
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• 2000

원자력 발전소의 중대사고는 비록 발생 확률은 매우 낮지만 사고 발생시 결말 효과가 크기 때문에 TMI 사고나 체르노빌 사고 이후 이에 대한 연구는 활발하게 진행되고 있다. 방사성 물질이 일단 환경으로 방출된 이후에 인체 및 환경에 영향을 미치는 주요 변수로는 풍향, 풍속, 강수량, 대기안정도로 대표되는 기상 조건과 방사선원 및 방출 고도, 열 함량, 방출 시간 등과 같은 방사선원 방출 특성에 관한 여러 가지 많은 변수들을 고려하여야 한다.(중략)

• Tunnel and Underground Space
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• v.34 no.2
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• pp.169-184
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• 2024

This study investigates acoustic emission (AE) and micro-deformation characteristics of circular openings through biaxial compression experiments. The experimental results showed a significant increase in the frequency, count, energy, and amplitude of AE signals immediately before damage occurred in the circular opening. The differences in frequency and count between before and after damage initiation were significantly pronounced, indicating suitable factors for identifying damage occurrence in circular openings. The results for digital image correlation (DIC) technique revealed that micro-deformation was concentrated around the openings, as evidenced by the spatial distribution of strain. In addition, spalling was observed at the end of the experiments. The AE and micro-deformation characteristics presented in this study are expected to serve as fundamental data for evaluating the stability of underground openings and boreholes for deep subsurface projects.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.8
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• pp.138-144
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• 2004

Satellite generates a complex electromagnetic noise by conducted and radiated coupling effect of the various electrical instruments. This noise may cause serious problems on the satellite system. To minimize the electromagnetic coupling effects and maintain the system safety margin, system noise reduction technique should be applied from the beginning of the system design. The KOMPSAT-2 system is evaluated by measuring the conducted noise on system electrical power leads and verifying a 6dB system safety margin under the complex noise environment with current injection. This paper describes the KOMPSAT-2 system evaluation result performed on ETB(Electrical Test Bed) and the analysed noise element, the analysed result will be reflected on FM(Flight Model) EMC test.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.973-978
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• 2010

The emission of volatile organic compounds (VOCs) from building materials is one of great concerns due to maintain airtight condition of a building to reduce energy consumption, and it causes the deterioration of indoor air quality. Therefore, the emission characterization of VOCs from building materials is necessary to improve indoor air quality. Emission characteristics of VOCs from a plywood flooring that is one of the most commonly used materials in an under-heating system, and from an adhesive that is generally used to stick a plywood flooring to a concrete floor were investigated using an emission chamber test in this study. It was found that the VOCs emission factor was dependent upon and proportional to indoor temperature, and the emission characteristics were closely related to the existing places and conditions of VOCs sources inside the building materials. Maximum emission factors of hexane and toluene from building materials were generally observed at the beginning, however, only that of toluene from a plywood flooring was shown after 6 hours from the beginning. It could be considered that the existing place and condition of toluene source inside a plywood flooring could influence on the VOCs emission. From this study, bake-out time more than 72 hours could be recommended before moving in to avoid the exposure to high concentration of VOCs emitted from an under-heating system.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.163-164
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• 2001

휘발성유기화합물(VOCs)과 포름알데히드(HCHO)의 발생원은 매우 다양할 뿐만아니라 주변환경과 인체에 미치는 영향이 매우 크다. VOCs와 포름알데히드의 발생원으로는 크게 인위적인 발생원, 자연적인 발생원, 실내에서의 발생원으로 구분할 수 있다. 현대인들의 하루생활 중 80%이상이 실내에서 이루어지고 있어 실내에서의 발생되는 오염물질에 대한 특성파악과 적절한 제어방안이 요구된다. VOCs와 포름알데히드의 발생원중에서 실내에서의 발생원으로는 여러 가지가 있으나, 신축건물과 리모델링에 사용되는 건축자재에서의 방출은 매우 크다고 할 수 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.111-113
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.261-262
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• 2003

현대인들은 하루 중 80∼90％ 이상의 많은 시간을 실내에서 생활하고 있어 실내에서의 발생되는 오염물질에 대한 특성파악은 무엇보다도 중요하다. 실내오염물질의 종류와 발생원은 매우 다양하며, 최근에는 산업발달과 더불어 수 많은 종류의 새로운 복합화합물질들이 발생되고 있다. 신축건물에 사용되는 건축자재는 휘발성유기화합물(VOCs)과 포름알데히드(HCHO)등의 다양한 유해화학물질들을 방출하고 실내공기질을 악화시키는 것으로 조사되고 있다. (중략)