• 센서학회지
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• 제12권1호
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• pp.24-33
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• 2003

This research is about a comfort sensing system for human environmental monitoring using a one-bodied humidity and temperature sensor and an air flow sensor. The thermal comfort that a human being feels in indoor environment has been known to be influenced mostly by six parameters, i.e. air temperature, radiation, air flow, humidity, activity level and clothing thermal resistance. Considering an environmental monitoring, we have designed and fabricated a one-bodied humidity and temperature sensor and an air flow sensor that detect air relative humidity, temperature and air flow in human environment using surface micromachining technologies. Micro-controller calculates a PMV (predicted mean vote) and CSV (comfort sensing vote) with sensing signals and display a PMV on LCD (liquid crystal display) for human comfort on indoor climate. Our work has demonstrated that a comfort sensing system can provide an effective means of measuring and monitoring the indoor comfort sensing index of a human being. Experimental results with simulated environment clearly suggest that our comfort sensing system can be used in many applications such as air conditioning system, feedback controlling in automobile, home and hospital etc..

• 대한기계학회논문집B
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• 제39권5호
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• pp.397-403
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• 2015

본 연구는 고분자 전해질 연료전지 (PEMFC)의 성능에 매우 중요한 영향을 미치는 물의 분포를 실험적으로 측정하였다. 내부에서 일어나는 활발한 화학반응과 물질전달 특성 때문에 PEMFC 내부에서 수분의 분포가 불균일하며 그 분포를 실험적으로 측정하기가 용이하지 않아 그 동안 간접적인 측정이 많이 이루어졌다. 본 연구에서는 초소형 온습도 센서를 연료전지의 채널에 직접 삽입하고 채널을 따라 흐르는 반응가스의 습도를 측정하였다. 수소극과 공기극 중 한곳만 가습하며, 가습하지 않은 곳에서 습도를 측정하여 멤브레인을 통한 물의 이동을 연구하였다. 가습기의 온도가 증가할수록 양극의 물농도 구배가 커져서 확산이 증가하나 높은 전류밀도에서는 전기삼투항력의 영향이 더욱 커졌다.

• 패션비즈니스
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• 제19권4호
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• pp.92-108
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• 2015

This study aimed at developing a down jacket prototype that utilized sunlight as an alternative energy source with no air pollution. The jacket is filled with flexible solar panels and has a heat-generating function and LED function. In this study, three smart down jacket prototypes were developed, and the jacket's capabilities were demonstrated through the thermal effect on the performance test. The typical output voltage of the flexible solar panels was 6.4V. By connecting the 2 solar cell modules in series, the final output voltage was 12.8V. A battery charge regulator module was used the KA 7809 (TO-220) of 9V. Three heating pads were to be inserted into the belly of the jacket as direct thermal heating elements, and the LED module was configured, separated by a flash and an indicator. The smart down jacket was designed to prevent damage to the down pack without the individual devices' interfering with the human body's motion. Because this study provides insulation from extreme cold with a purpose, the jacket was tested for heat insulation properties of non-heating, heating on the back, heating on the abdomen, and heating on both the back and abdomen in a sitting posture in a static state. Thermal property analysis results from examining the average skin temperature, core temperature, and the temperature and humidity within clothing showed, that placing a heating element in one place was more effective than distributing the heating elements in different locations. Heating on the back was the most effective for maintaining optimal skin temperature, core temperature, and humidity, whereas heating on the abdomen was not effective for maintaining optimal skin temperature, core temperature, or humidity within clothing because of the gap between the jacket and the body.

• Geomechanics and Engineering
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• 제27권6호
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• pp.583-594
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• 2021

The gas permeability behavior of unsaturated bentonite-based materials is of major importance for ensuring effective sealing of high-level radwaste repositories. This study investigated this by taking a sample of Granular Bentonite Material (GBM) at the end of the Engineered Barrier Emplacement (EB) experiment in the Opalinus Clay, placing it under different humidity conditions until it achieved equilibration, and testing the change in the gas permeability under loading and unloading. Environmental humidity is shown to have a significant effect on the water content, saturation, porosity and dry density of GBM and to affect its gas permeability. Higher sensitivity to confining pressure is exhibited by samples equilibrated at higher relative humidity (RH). It should be noted that for the sample at RH=98%, when the confining pressure is raised from 1 MPa to 6 MPa, gas permeability can be reduced from 10^-16 m² to 10^-19 m², which is close to the requirements of gas tightness. Due to higher water content and easier compressibility, samples equilibrated under higher RH show greater irreversibility during the loading and unloading process. The effective gas permeability of highly saturated samples can be increased by 2-3 orders of magnitude after 105℃ drying. In addition, cracks possibly occurred during the dehydration and drying process will become the main channel for gas migration, which will greatly affect the sealing performance of GBM.

• Journal of the Korean Wood Science and Technology
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• 제47권6호
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• pp.721-731
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• 2019

천연건조는 건조되는 목재의 수종, 밀도와 크기, 천연건조장의 위치조건과 함께 건조지역의 기상인자를 고려해야 한다. 우리나라와 같이 4계절의 구분이 있는 지역은 여름과 겨울의 온도 및 상대습도의 차이가 크기 때문에 기상인자에 대한 연구가 필요하다. 본 연구에서는 소나무 원목의 천연건조 중 함수율 변화를 분석하기 위한 기초자료로 국내 24지역의 1988년부터 2017년까지 30년간 월별 평균 기온, 상대습도, 풍속의 기상인자를 이용하여 유효천연건조일수를 산출하였다. 24지역의 유효천연건조일수는 239 - 291일 범위로 평균값은 265일이었다. 이 결과는 1955년부터 1984년까지의 기상인자로 산출된 유효천연건조일수의 평균인 260일 비하여 약 5일 증가한 값이다. 유효천연건조일수와 기상인자들의 다중회귀분석 결과, 유효천연건조일수에 영향을 미치는 기상인자는 온도, 상대습도, 풍속의 순서였다. 지역별로 산출된 유효천연건조일수를 이용하여 우리나라를 4개의 유효천연건조일수대로 구분한 결과, 유효천연건조일수대가 지구온난화의 영향으로 선행연구에서 제시된 것에 비하여 위도상 북쪽으로 상승하였다. 서울지역에서 수행된 소나무 원목의 천연건조 중 함수율 분포를 예측하기 위한 기초자료로 2016년부터 2018년까지 3년간의 월별 평균온도, 상대습도, 풍속의 기상인자를 제시하고, 그에 따른 평형함수율 변화를 조사하였다.

• Journal of the Korean Wood Science and Technology
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• 제42권1호
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• pp.49-57
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• 2014

최종함수율은 예비천연건조를 수행한 시험재에서 더 균일하게 건조가 가능하였으며, 예비천연건조 후 고온저습건조시 최종함수율은 초기함수율에 영향을 받는 것으로 사료된다. 재면할렬 억제 효과는 예비천연건조를 수행한 시험재에서 더 효과적인 것으로 조사되었으나, 예비천연건조 중 발생된 재면할렬에 의한 영향이 크기 때문에 예비천연건조 중할렬발생 억제가 중요할 것으로 판단된다. 부분엔드코팅은 내부할렬, 표면경화율, 비틀림, 수축율에 미치는 영향이 없는 것으로 조사되었다. 예비천연건조는 고온저습건조 중 내층에 발생하는 인장응력을 감소시켜 내부할렬의 발생을 매우 효과적으로 억제하고 표면경화율을 감소시키는 것으로 조사되었다. 비틀림의 경우 함수율감소에 따른 수축으로 인하여 비틀림의 정도가 증가되었다.

• 공업화학
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• 제21권2호
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• pp.169-173
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• 2010

다양한 형태의 염들이 수분 제거능력을 지니고 있다. 이러한 수분의 제거 능력은 함습기체의 온도와 공급된 유량에 따라 결정된다. 본 연구에서는 용해성 건조제를 사용하는 제습공정에 유입되는 공기의 유량과 온도, 그리고 용해성 건조제의 양이 제습특성에 미치는 영향에 대한 연구를 수행하였다. 사용된 용해성 건조제는 수용성 공정에서 나트륨(Na) 또는 칼륨(K)이 주성분이 되도록 합성하고 제습특성에 대하여 검토하였다. 연구 결과 다음과 같은 몇 가지 결론을 얻을 수 있었다. 용해성 건조제의 주성분에 관계없이 열적 특성은 유사한 결과를 보여주고 있다. 습도가 70~93%이고 공기의 유량이 $0.22{\sim}0.69m^3/s$인 조건에서 Na가 주성분인 용해성 건조제가 제습공정에 효율적이었다. 또한 이슬점은 공기의 유입량에 따라 증가하였으며, 제습공정에서 상대습도의 변화는 용해성 건조제의 양에 비례하는 결과를 보였다.

• Journal of Ginseng Research
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• 제40권1호
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• pp.90-96
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• 2016

Background: Knowledge on microclimate conditions under artificial shades in a ginseng field would facilitate climate-aware management of ginseng production. Methods: Weather data were measured under the shade and outside the shade at two fields located in Gochang-gun and Jeongeup-si, Korea, in 2011 and 2012 seasons to assess temperature and humidity conditions under the shade. An empirical approach was developed and validated for the estimation of leaf wetness duration (LWD) using weather measurements outside the shade as inputs to the model. Results: Air temperature and relative humidity were similar between under the shade and outside the shade. For example, temperature conditions favorable for ginseng growth, e.g., between $8^{\circ}C$ and $27^{\circ}C$, occurred slightly less frequently in hours during night times under the shade (91%) than outside (92%). Humidity conditions favorable for development of a foliar disease, e.g., relative humidity > 70%, occurred slightly more frequently under the shade (84%) than outside (82%). Effectiveness of correction schemes to an empirical LWD model differed by rainfall conditions for the estimation of LWD under the shade using weather measurements outside the shade as inputs to the model. During dew eligible days, a correction scheme to an empirical LWD model was slightly effective (10%) in reducing estimation errors under the shade. However, another correction approach during rainfall eligible days reduced errors of LWD estimation by 17%. Conclusion: Weather measurements outside the shade and LWD estimates derived from these measurements would be useful as inputs for decision support systems to predict ginseng growth and disease development.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.682-687
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• 2000

In this research the remaining service life of the concrete due to the steel corrosion was predicted by three cases; causing carbonation, using sea sand, using deicing salts. In case of deterioration by carbonation, effective carbonation depth, effective coverage depth and relative humidity are considered for predicting method. In case of using sea sand, predicting method is made of rust growth equation from polarization resistance method. In case of using deicing salts, predicting method is made of transformation of Fick's law. Three methods are very useful in predicting service life of concrete.

• 대기
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• 제17권1호
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• pp.109-114
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• 2007

The mist on the inside of an automobile windshield is not only uncomfortable but also very dangerous because it obstructs the driver's vision. However, the removal process of the mist has never been studied in detail. This study performed experiments analyzing the mechanism causes the mist in a car and investigated the appropriate removal process. The experiments were performed on two rainy days, 10 April 2006 and 26 May 2006, with temperature and relative humidity sensors of testo-175-H2 and DICKSON-TK500. We found a passenger increased water vapor by 0.2 g $min^{-1}$ through respiration and thereby relative humidity (RH) from 55% to 67% in 8 minutes. Even though RH was not saturated, misting occurred because the humid air contacted the colder surface of the window. To remove the mist, it is necessary to increase the temperature or inflow drier air in the car. Therefore, we expected that the heater would be more effective than air conditioner for this matter. However, the outcome was the other way around due to the structure of the heating and cooling system in the car. When the air-conditioner was on, colder and drier air was generated and flowed through the so-called evaporator. Droplets were produced in the evaporator due to cooling procedure. When the heater was on, the warm air evaporated the droplets and increased the water content in the air resulting in an increase of relative humidity. Consequently, the air conditioner is more effective than the heater to remove the mist.