• Tunnel and Underground Space
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• v.21 no.4
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• pp.287-296
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• 2011

We performed a numerical modeling study of thermodynamic and multiphase fluid flow processes associated with underground compressed air energy storage (CAES) in a lined rock cavern (LRC). We investigated air tightness performance by calculating air leakage rate of the underground storage cavern with concrete linings at a comparatively shallow depth of 100 m. Our air-mass balance analysis showed that the key parameter to assure the long-term air tightness of such a system was the permeability of both concrete linings and surrounding rock mass. It was noted that concrete linings with a permeability of less than $1.0{\times}10^{-18}\;m^2$ would result in an acceptable air leakage rate of less than 1% with the operational pressure range between 5 and 8 MPa. We also found that air leakage could be effectively prevented and the air tightness performance of underground lined rock cavern is enhanced if the concrete lining is kept at a higher moisture content.

• Land and Housing Review
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• v.5 no.4
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• pp.325-332
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• 2014

The purpose of this study was to measure the airtightness and Air-Flow Performance for 7th house of small apartment houses adopted window frame-type natural ventilation. All window and living room door is provide with window frame-type natural ventilation, and there is provide with manual controller. As the object of measurement, the 6th type small apartment houses with area of $33m^2$ to $51m^2$ was selected. airtightness performance was measured at the front door using Blower door system. We measured ventilation rate per hour on 50Pa pressure different between inside and outside by the 1st to 6th cases. As a result, when the natural ventilation frame was closed, average amounts are shown as the ventilation rate per hour were 2.27ACH (CASE1). and the result is similar to general apartment house (1.65~4.28ACH). When the natural ventilation frame was open, average amounts are shown as the ventilation rate per hour were 5.87ACH (CASE6). In addition, that's a 3.6ACH increased more than CASE1.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.120-123
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• 2009

건물에서 에너지손실이 큰 창호에 대해 최저소비효율기준 및 에너지소비효율 등급기준(안) 도입을 통해 지속가능한 고효율 창호의 보급 활성화 촉진과 관련 산업의 기술 및 산업력 향상을 적극적으로 유도할 필요가 있다. 이에 본 연구에서는 창호의 에너지 효율화를 위하여 고효율기자재(고기밀성 단열창호)로 인증받은 약 100여개 제품과 기타 제품에 대하여 창호 유형별 기밀 및 단열성능의 조사 분석을 통하여 창호 관련 제도 개정에 기초자료로 활용 에너지절약과 기후변화협약 관련 건물부문의 구체적 실천 대응방안으로 활용하고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.517-520
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• 2017

In this paper, we represented the structural design parameter effect on the sealing gap behavior of solid rocket motor case and nozzle connection under penetrated pressure through the sealing path between insulation rubber and the ablative FRP bonded on the inside convergent wall of nozzle. It is important to keep the good sealing capacity during all the combustion time of SRM. To achieve the crucial role of sealing system of SRM, designers must consider design factors for stable sealing clearance gap as the nearly unchanged initial design state as possible for sufficient compression rate of O-ring under sealing gap pressure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.260-263
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• 2008

공항에 인접한 주거지역에서 항공기 소음문제로 인하여 거주자들에게 소음피해가 발생하고 있다. 이러한 항공기소음을 저감하기 위한 방법 중 건물외피를 차음성능이 높은 구조로 변경하여 건축물의 차음량을 개선시키는 수음원 대책이 일반적으로 사용되고 있다. 특히 건축물 방음시설 설치는 건물외피 중 외부소음에 가장 취약한 창호의 차음량을 증가시키는 것이 효과적인데, 본 연구에서는 기존 창호에 비하여 차음성능이 높은 창호를 교체 설치하여 건축물의 차음량 개선치를 $L_{max}$, SEL, $L_{eq}$로 각각 검토 비교함과 동시에 창호의 기밀성능을 위한 기밀재 및 추가 모헤어의 설치조건에 따른 차음성능을 검토해 보았다. 측정결과 방음시설 설치 후 항공기소음을 $L_{max}$, SEL, $L_{eq}$로 차음량 개선치를 각각 평가한 결과 1.8dB 이내의 편차를 갖는 것으로 나타났으며, 창의 차음성능 개선치는 기밀재 설치 후 $R'45^{\circ}$,w가 5dB, 기밀재 및 추가 모헤어 설치 후 8dB로 나타났다.

• Korean Architects
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• no.1 s.142
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• pp.32-34
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• 1981

• Journal of Energy Engineering
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• v.24 no.4
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• pp.63-70
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• 2015

Crevices between window and window frame cause not only heat losses but also serve path to sound transmission and infiltration of fine dusts that are harmful to humans. There were many efforts in the past to eliminate these crevices but because of the windows' indispensable function of opening and closing, it was an unsolvable problem. In this study, a new type sliding window is developed by applying horizontally rolling wheels to implement a surface sealing which is excellent for enhancing air tightness. To evaluate the feasibility of the newly developed window, forces for opening and closing, durability and air tightness were testet according to Korean Testing Standards. Force for opening a 2000 N window is 30 N. It endured 100,000 cycles of opening and closing. Infiltration was $0.00m^3/(m^2h)$ for a pressure difference of 10 Pa. Since this window has few moving parts, it has favorable features of low cost and few breakdown.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.855-860
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• 2001

As being inconvenient to apply reinforced concrete structure to high-rise buildings. it is applied steel structured system. Therefore light-weight wall systems are applied as partition wall to reduce the self-load of the building. But. the required performances of a light-weight wall are not evaluated systematically. As a field survey result. partition walls of house-to-house and room-to-room were not showed their respected performances. so the dwellers are feel so worse the quality of the whole building. In steel-structured high-rise buildings especially. occupant's dissatisfaction concerned indoor noise was high because curtain wall systems having a high air-tight performance isolate the outdoor noise making masking effect. Also to suppress indoor air movement. stact effect must be concerned. Therefore wall systems which have high performances of sound insulation and air-tightness are required in high-rise buildings.

• Review of KIISC
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• v.6 no.1
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• pp.65-78
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• 1996

본 논문에서는 JPEG 알고리즘을 이용하여 화상데이터를 부호화할때 디지털 서명문과 같은 기밀 데이터를 몰래 집어넣어 합성하는 방식에 대하여 고찰한다 그 기본원리는 DCT 계수를 양자화 할 때 필연적으로 생기는 오차를 이용하는 것으로 0이 아닌 양자화 계수를 합성하고자 하는 기밀데이터에 따라 근처의 정수로 조절하는 것이다. 이 방식을 SIDBA 표준화상에 적용하여 화상의 열화는 무시할 정도로 작으면서 원하는 크기의 기밀 데이터를 합성할 수 있음을 보인다. 또한, 화질의 열화를 최소화시키면서 일정량의 기밀 데이터를 합성시키기 위하여 블록당 1화소를 적절히 선택하여 제3자의 공격에 대한 안전성을 향상시키는 방법을 제시하고 컴퓨터 시뮬레이션을 통하여 성능을 분석한다.

• Solar Energy
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• v.15 no.3
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• pp.119-125
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• 1995

Since the using of heating energy associated with infiltration is significant in a building, the efforts to minimize the infiltration while ensuring minimum ventilation rates for various types of occupancy will be beneficial. In constrast to that many efforts have been made to reduce heat loss by improving thermal resistance of building envelope, little has been tried to reduce heat loss from infiltration. For achieving such an objective, measurement of air leakage rate will be pre-requisite as a diagnostic tool. A blower door system, a depressurization/pressurization method, was employed and it demonstrated a good potential for measuring airtightness performance of residential buildings. Based on the test results, annual energy savings for residential heating was estimated by reducing infiltration to a level of reasonably airtight or to a level of ASHRAE Standard 62-1989 for minimum ventilation.