• Title/Summary/Keyword: Tightness

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STRONG τ-MONOLITHICITY AND FRECHET-URYSOHN PROPERTIES ON Cp(X)

  • Kim, Jun-Hui;Cho, Myung-Hyun
    • Honam Mathematical Journal
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    • v.31 no.2
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    • pp.233-237
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    • 2009
  • In this paper, we show that: (1) every strongly ${\omega}$-monolithic space X with countable fan-tightness is Fr$\'{e}$chet-Urysohn; (2) a direct proof of that X is Lindel$\"{o}$f when $C_p$(X) is Fr$\'{e}$chet-Urysohn; and (3) X is Lindel$\"{o}$f when X is paraLindel$\"{o}$f and $C_p$(X) is AP. (3) is a generalization of the result of [8]. And we give two questions related to Fr$\'{e}$chet-Urysohn and AP properties on $C_p$(X).

The Mortar Properties of Portland Cements Blended with Modified Coal Ashes (가공된 석탄재를 사용한 석탄재혼합시멘트의 모르터 특성)

  • 홍원표;노재성;조헌영;정수영;김무한
    • Journal of the Korean Ceramic Society
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    • v.27 no.7
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    • pp.833-840
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    • 1990
  • For the development of multi-functional materials which has water reducing power, air entraining power and waterproofing power as well as blending additive in cement mortar the coal ash was modified with asphalt-stearic acid or asphalt-boiled oil mixtures by mechanical treatment. And the physical properties of cement mortar blended with modified coal ashes were compared with those of the water-tightness-cement mortar and the ordinary-portland-cement mortar added with AE.water reducing agent. The mortar of coalash-blend-cement modified with asphalt-stearic mixture was increased acid about 20% in initial strengths and decreased about 20% in water absorption ratio than those of ordinary coalash-blend-cement. The mortar of coalash-blend-cement modified with asphalt-bolied oil mixture was similar to the cement mortar added with AE.water reducing agent in water reduction ratio, air entraining conents and the initial strengths, also was similar to the water-tightness-cement mortar in water absorption and water permeability ratios.

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Stack Effect in High-Rise Buildings: A Review

  • Mijorski, Sergey;Cammelli, Stefano
    • International Journal of High-Rise Buildings
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    • v.5 no.4
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    • pp.327-338
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    • 2016
  • This technical paper presents a detailed review of the stack effect phenomenon and of the associated implications pertaining to the design and construction of high-rise buildings in regions of extreme climatic conditions. The present review is focused on both the classical 'chimney' effect as well as on the reverse stack effect, which are respectively related to cold and hot climates. For the purposed of the work here presented, the ASHRAE (2013) design conditions of Astana (Kazakhstan) and Riyadh (Kingdom of Saudi Arabia) were selected. A 230 m tall residential building of rectangular floor plan was numerically modelled in the context of the climatic conditions of the two abovementioned cities and a number of sensitivity analyses were performed, covering parametric changes of: temperature, façade air tightness, site wind speeds and wind directions.

A Research on Air-tightness and Thermal performance of windows system classified by Windows type (에너지효율화를 위한 창호 유형별 기밀 및 단열성능에 관한 조사 연구)

  • Choi, Gyeong-Seok;Kang, Jae-Sik;Yang, Kwan-Seob;Lee, Seung-Eon
    • 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.

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A Study on the Development of Lightweight Wall for Sound Transmission Loss and Field Test Results of the Dry-Wall System (차음성능이 향상된 경량벽체 개발 및 성능평가 연구)

  • 이병권;배상환;홍천화
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.699-704
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    • 2004
  • 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 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. Therefore wall systems which have high performances of sound insulation and air-tightness are required in high-rise buildings. As a result, a new drywall system was presented and the performance was verified with field test.

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A Case of Aberrant Right Subclavian Artery (Arteria Lusoria) with Chest Tightness and Coughing (요골동맥을 통한 관상동맥촬영 중 진단된 편위된 우측쇄골하동맥 1예)

  • Han, Seung-Hee;Kim, Su-Young;Park, Hye-Kyong;Park, Jong-Sung
    • Journal of Yeungnam Medical Science
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    • v.29 no.1
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    • pp.61-64
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    • 2012
  • The left aortic arch with an aberrant right subclavian artery, or arteria lusoria, is the most common aortic arch anomaly, occurring in 0.5-2.5% of individuals. In such cases, the angular course of the arteria lusoria to the ascending aorta imposes difficulty in passing a guide wire to the ascending aorta during right transradial catheterization. Here, the case of a 53-year-old woman with intermittent chest tightness and coughing is reported. Aberrant right subclavian artery (arteria lusoria) was diagnosed via aortogram during right transradial coronary angiography. Compression of the esophagus and trachea by the aberrant right subclavian artery was demonstrated by chest computed tomography (CT).

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Comparison of evaluation methods for measuring pressure of compressionwear (컴프레션웨어의 압박감 측정 방법 비교 연구)

  • Park, Jee Hye;Chun, Jongsuk
    • The Research Journal of the Costume Culture
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    • v.21 no.4
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    • pp.535-545
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    • 2013
  • The aim of this study was comparing measuring tools for detecting physical comfortness with variation of garment pressure. The measuring tools for detecting physical comfortness were EEG and survey questionnaire. Two low-pressure compressionwears and a commercial compressionwear (girdle) were tested. Results showed that the questionnaire survey well detected suffocation or motion comfortness. But it did not discrete the appropriate tightness of the compressionwears. The results of EEG analysis show that the absolute power of ${\alpha}$-wave value was elevated with the low-pressure compressionwears. It also showed lower stress value. The high-pressure compressionwear presented decreased absolute power of ${\alpha}$-wave value. It showed higher stress value. These results implicate that EEG can appropriatly indicate the change of physical comfortness of compressionwear. The appropriate tightness of compressionwear can be measured with EEG analysis rather than survey questionnaire.

Development of Optical Device Housing Compacted Using SUS304L Granulated Powders

  • Suzuki, Hironori;Hara, Toshihiro;Ogino, Yukinobu;Sato, Yasushi;Tomota, Yo
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.754-755
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    • 2006
  • In order to develop the SUS304L housing by powder metallurgy for an optical device useful for the FTTH communication system, the optimum compacting pressure and sintering temperature were investigated using granulated powder as the material to satisfy high air-tightness and high laser-weldability. Then the laser-welding test of specimen made under the optimum condition was carried out to observe welding sputters.

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Experimental Study on Airtightness Performance of the House with High Levels of Insulation and Airtight Construction (고기밀 고단열 주택의 기밀성능에 관한 실험적 연구)

  • Shin, U-Cheul;Yoon, Jong-Ho;Baek, Nam-Choon
    • Journal of the Korean Solar Energy Society
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    • v.25 no.4
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    • pp.61-67
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    • 2005
  • The purpose of this study is to evaluate the air tightness of Zero Energy Solar House(ZeSH) and to propose the construction improvement of junctions and penetrations where air infiltration was identified. Air leakage rate were measured by means of blower door test in accordance with ASTM E779-87. The results showed that ZeSH has an excellent airtightness with ACH50/20 (air change per hour at a pressure difference of 50 Pa between inside outside) of 0.34hr-1 and leakage class E by normalized leakage area of ASHRAE.

An Experimental Study on Improving Water Tightness of Concrete Surface Applied High Growth Organic Crystalization Material (고성장 유기결정체의 성장 특성을 이용한 콘크리트 표층부의 수밀성 개선에 관한 연구)

  • Song Je-Young;Kang Hyo-Jin;Oh Sang-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.817-820
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    • 2004
  • Our country was much developments in change of construction environment along with fast economy development. But, various problems that must think in problem of safety and quality were appeared. Constructions which build through rapid economy development are getting many social criticisms to problem of crack and water leakage at use process. Is situation that huge repair expense to cure this is engaged. Safety problem of construction is indicated socially through various media mediums again.

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