• 한국도로학회:학술대회논문집
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• 한국도로학회 2008년도 추계학술대회 논문집
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• pp.419-422
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• 2008

• 콘크리트학회지
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• 제6권4호
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• pp.102-112
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• 1994

콘크리트의 건조수축은 수분확산과 밀접한 관계가 있으며, 수분확산과정은 온도와 습도에 의해 많은 영향을 받는다. 또한 물-시멘트비나 골재의 품질등에 의해서도 영향을 받기 때문에 고차의 비선형성을 보인다. 이 연구에서는 먼저 시간에 따른 콘크리트내의 수분분포를 해석하는 프로그램을 개발하고, 그리고 크리이프 및 온도와 숙성도에 따른 탄성계수의 변화를 고려하여 부등건조수축 및 부등응력을 계산하는 프로그램을 개발하였다. 이 프로그램에 의한 해석값들을 BP-KX 모델에 의해 계산된 건조수축값 및 실험값과 비교하여 좋은 결과를 보여 주었으며, 콘크리트내의 응력은 시간과 위치에 따라 정량적으로 계산되었다.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.67-73
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• 1995

This study was undertaken to investigate the effect of heat treatment on the dynamic viscoelasticity of three species of Phyllostachys bambusoides, Phyllostachys nigra var. henonis and Phyllostachys pubescens, grown in southern Korea. The bamboo was treated for 3~24 hours at $60{\sim}180^{\circ}C$, and then was treated in a climatic chamber for 3~48 hours at $40^{\circ}C$ and 95% relative humidity. The results obtained are summarized as follows : 1. Dynamic Young's modulus decreased with increasing temperature and duration of the heat treatment. 2. Internal friction decreased with increasing treatment duration. 3. Moisture absorption decreased with increasing temperature and duration of the heat treatment. 4. Dynamic viscoelasticity decreased, whereas internal friction slowly increased, with increasing moisture content.

• 한국연초학회지
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• 제14권1호
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• pp.57-65
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• 1992

The quality of cut tobacco will be deteriorated due to weather conditions such as temperature and relative humidity, when shipping and long term storaging. The change of equilibrium moisture contents in cut tobacco were under influence of relative humidity and temperature but not humectants. Therefore internal packing materials are necessary for cut tobacco to maintain initial quality, including taste, flavour and musty smell during shipping or storaging. When packing cut tobacco for shipping or long term storaging, desiralbe packing density was 200/$m^2$, For the long term storage under R.H 90% and 3$0^{\circ}C$, polyethylene film thickness suitable for packing material are above 100$\mu$, which resulted in 42days of shelf life.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.31-32
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• 2020

Concrete changes its internal moisture distribution depending on the external environment, and changes in the condition of the material's interior over time affect the performance of the concrete. These effects are closely related to the long-term behavior and durability of concrete, and the degree of deterioration varies from climate to climate in each region. In this study, we use actual climate data from each region with distinct climates. A multi-physical analysis based on the method was conducted to predict the difference and degree of deterioration rate by climate.

• 산업경영시스템학회지
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• 제36권3호
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• pp.142-149
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• 2013

Among ammunitions which are stored in a war field, the lifespan of propelling gunpowder is affected by storage environment such as storage temperature, humidity, and exposure to sunlight. These are because Nitrocellulose (NC) which is the main component of propelling gunpowder can be naturally disassembled to unstable substances similar with other nitric acid ester. We can't prevent it fundamentally from being disassembled, but to restrain induction of automatic disassembly by decomposition product, a decomposition product ($NO_2$, $NO_3$, and $HNO_3$) and tranquillizer DPA (Diphenylamine), having high reactivity, are added into a propellant. For this, it will decrease the velocity of tranquillizer which can also affect the velocity of producing the decomposition product of NC, storage temperature or humidity of propelling gunpowder is higher, drop of tranquillizer content is much faster. Therefore, to extend storage lifespan of propelling gunpowder, it is really important to control storage temperature or humidity inside the magazine. Hereupon, according to the manufacture of small scale model magazine and the result of performing experiments and measuring variation of inside temperature (storage temperature), using roof types that have a steel slate structure of magazine among ground magazines, this research shows the differences in details.

• Journal of Preventive Medicine and Public Health
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• 제39권2호
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• pp.171-176
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• 2006

Objectives : The objective of this study is to assess the factors influencing biological monitoring of textile coating factory workers exposed to N,N-dimethylformamide(DMF). Methods : We studied 35 workers who were occupationally exposed to DMF from 9 textile coating factories. The study was carried out in two phases; summer and winter. While air concentration of DMF, temperature and humidity were assessed in order to monitor the atmospheric conditions, biological monitoring was done to determine the internal dose by analyzing the N-methylformamide(NMF) collected from urine at the beginning and end of the shift. Questionnaires and medical surveillance were also obtained during the two phases. Results : Median air concentrations of DMF in winter and summer were 1.85 ppm and 2.78 ppm respectively. Also the difference between the urinary NMF concentration at the beginning and end of the shift $({\Delta}NMF)$ was always significant in each season (P < 0.001). The correlations between log DMF in air, log end-of-shift urinary NMF (r=0.555, P < 0.001) and log ${\Delta}NMF$ (r = 0.444, P < 0.001) was statistically significant in summer. The temperature, humidity, a shift system and different styles of clothing worn were significantly different during the two phases. In a multivariate analysis, temperature and the concentration of DMF in the air were the main factors influencing biological monitoring of textile coating factory workers. Conclusions : Concerning more comprehensive prevention measures to reduce exposure for those workers occupationally exposed to DMF, dermal exposure conditions such as temperature and humidity together with the air concentration of DMF should be assessed and biological monitoring is necessary to reduce adverse health effects, especially during the summer.

• 한국방재학회 논문집
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• 제9권2호
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• pp.1-9
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• 2009

물-결합재비 0.4이하의 고성능 콘크리트 수축 변형을 파악하기 위해 전체 수축을 수분의 외부이동에 의한 건조수축과 수분의 내부소모에 의한 자기수축으로 분리한 후, 자기건조에 의한 상대습도 변화와 변형률의 관계를 묘사하기 위하여 계면역학적 접근법에 의한 습도-변형률 관계를 설정하였다. 이에 대한 검증을 위해 자기수축 시험체에서의 습도-수축 측정을 수행하였으며, 기존 연구 모델인 Tazawa, CEB-FIP 모델에 비하여 측정값과 가장 유사한 결과를 나타내어 본 연구에서의 자기수축모델은 자기건조에 따른 자기수축은 선형성을 나타내는 수분의 외부이동에 의한 수축과는 달리 지수적 관계를 갖는 특성과 초기재령에서의 급속한 자기수축 발현 특성을 적절히 묘사하고 있음을 알 수 있었다. 이 후 본 연구의 수분이동-수축 모델을 반영하여 온도, 수분이동, 변형률 해석의 다중물리 모델 해석과 모형시험체 측정을 수행한 결과 매우 유사한 값을 나타내어 본 연구를 통해 측정된 수분의 내부소모에 의한 습도와 수축변형률을 고려한 다중물리모델은 타당할 것으로 판단된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.264-265
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• 2008

While the reliability of bulk insulation has become important particularly in multilayer boards and embedded boards, electronics are to be used under various environments such as at high temperature and in high humidity. We observed internal space charge behavior for two types of epoxy composites under dc electric fields to investigate the influence of water at high temperature. In the case of glass/epoxy specimen, homocharge is observed at water-treated specimen, and spatial oscillations become clearer in the water-treated specimens. Electric field in the vicinity of the electrodes shows the injection of homocharge. In aramid/epoxy specimens, heterocharge is observed at water-treated specimens, i.e. negative charge accumulates near the anode, while positive charge accumulates near the cathode. Electric field is enhanced just before each electrode. In order to further examine the mechanism of space charge formation, we have developed a new system that allows in situ space charge observation during ion migration tests at high temperature and high humidity. Using this in situ system.

• 전기화학회지
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• 제6권3호
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• pp.212-216
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• 2003

고분자전해질형 연료전지에 사용되는 외부 및 내부 가습기를 통과한 반응 기체의 상대습도와 온도를 측정한 자료가 실시간으로 컴퓨터에 입력되어지는 시스템을 자체적으로 구성하였다. 이 시스템을 이용하여 측정한 경우 10-20분이 경과한 후에 습도 값이 안정되었으므로 가습 측정치에 대한 신뢰성을 향상시킬 수 있었으며, 여러 가지 가습의 영향을 해석할 수 있었다. 측정 장비의 이상을 초래할 수 있는 상대 습도가 $100\%$부근의 영역에서 지속적으로 측정을 수행할 경우 센서의 오작동 내지 고장의 원인이 될 수 있었으므로 실험시 주의가 필요하였다. 가습기를 통과한 반응기체는 유량이 증가할수록 가습되는 양은 증가하나, 일정 유량 이상이 되면 그 증가폭이 감소하는 경향을 보였는데 이는 가습기 출 통과하는 기체의 체류 시간 영향에 기인한 것으로 추정되어진다.