• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.50-51
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• 2022

현재 사용되는 2차 전지의 특성상 저온 및 고온에 반응하는 특성이 나타나고 있다. 이러한 특성을 고려하여 충방전제어를 진행하면서 사용 되는 2차 전지의 활용을 최대한 운영이 가능한 방법을 제시 하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.545-551
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• 2018

For domestic application of the temperature gradient model proposed by foreign design standards, a specimen of steel box girder bridge was fabricated with the following dimensions: 2.0 m width, 2.0 m height and 3.0 m length. Temperature was measured using 24 temperature gauges during the summer of 2016. The reliability of the measured data was verified by comparing the measured air temperature with the ambient air temperature of the Korea Meteorological Administration. Of the measured gauges, four temperature gauges that can be compared with the temperature difference of the Euro code were selected and used to analyze the distribution of the measured temperatures at each point. The reference atmospheric temperature for the selection of the maximum temperature difference was determined by considering the standard error. Maximum and minimum temperatures were calculated from the four selected points and the resulting temperature difference was calculated. The model for the temperature difference in the steel box girder bridge was shown by graphing the temperature difference. Compared to the temperature distribution of the Euro code, the presented temperature difference model showed a temperature difference of $0.9^{\circ}C$ at the top and of $0.3^{\circ}$ to $0.4^{\circ}C$ at the intermediate part. These results suggested that the presented model could be considered relatively similar to the Euro code The calculated standard error coefficient was 2.71 to 2.84 times the standard error and represents a range of values. The proposed temperature difference model may be used to generate basic data for calculating the temperature difference in temperature load design.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.236-238
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• 2009

에너지 절약차원에서 냉방을 줄여 지구온난화 방지에 일조하고자 여름철에 가벼운 차림의 의복을 권장하는 쿨비즈 캠페인이 시작되었으나 이의 정량적인 효과를 분석하는 연구가 미흡하였다. 본 연구에서는 여름철 온실가스 줄이기 및 직장인 등의 건강증진 등을 위하여 기후복장 적응형에 대한 범국민 인식 및 실천 필요를 바탕으로, 실험을 통해 쿨비즈에 의한 생리적 반응 측정 및 주관적 감각평가를 실시하였다. 1 차실험은 두 복장(전통의복,기후의복)의 피부온 측정실험으로, 환경온 25, $27^{\circ}C$, 상대습도 50% RH 에서 20 대 성인남성 4 명을 대상으로 실험을 하였다. 피험자는 심신을 안정할 수 있도록 30 분간의 안정기를 가진 후에 60 분 동안 실험을 하였으며, 사무실 내 작업환경과 같은 분위기 조성을 위해 편안하게 의자에 앉아 가벼운 대화나 컴퓨터 워드작업 및 설문을 응할 수 있도록 피험자 앞 책상 위에는 노트북을 설치해 두었고, 실험 진행기간 동안 피부온, 직장온, 습도, 발한량, 열화상 카메라, 온열감, 습윤감, 쾌적감 등과 같은 주관적 감각을 측정하였다. 2 차 실험은 동일 피부온 발현하는 환경온 찾기로 기준온도($27^{\circ}C$)에서 전통복장을 입고 온도를 점진적으로 하강시키면서 $27^{\circ}C$ 기후 복장을 입은 상태의 피부온도와 동일해지는 실내온도를 측정한다. 착의 형태에 따른 피부온도 변화에서 환경온도 $25^{\circ}C$ 전통의복 기후의복에 의한 피부온도의 차이는 전통의복이 최소 0.3~최대 $1.6^{\circ}C$ 더 높게 나타났으며, 환경온도 $27^{\circ}C$에서 전통의복 기후의복에 의한 피부온도의 차이는 대체적으로 전통의복이 최소 0.4~최대 $1.0^{\circ}C$ 더 높게 나타났다. 주관적 감각평가에서도 기후의복보다 전통의복에서 온열감 습윤감 불쾌감이 더 높은 경향을 보였다. 주관적 감각으로는 $25^{\circ}C$ 전통의복과 $27^{\circ}C$ 기후의복에서 중립적인 느낌을 나타냈다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.22-22
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• 2019

최근 전 세계적으로 급증하는 기후변화의 영향으로 인해 강우량 증가에 따른 이상홍수 발생 및 댐 여유고 부족 등 다양한 위험인자가 노출되고 있다. 이러한 예상치 못한 이상홍수는 실제 거주하고 있는 사람들을 위협할 수 있으며, 하천 범람으로 인해 2차 3차 피해가 일어날 가능성이 존재하고 있다. 이에 다양한 자연재해로부터 인명 및 재산 피해를 방지 및 저감하기 위한 목적으로 다양한 수공구조물이 존재하며, 수자원 관리계획 수립의 목적에 따라 다양한 강수량이 활용되고 있다. 특히, 지구온난화에 따른 기후변화 영향을 고려한 연최대 강수량 및 확률강수량 산정이 필요한 시점이며, 온도변화에 따른 증기압 계산식인 Clausius-Clapeyron 관계에 따르면 대기 온도가 $1^{\circ}C$ 상승할 때 대기수분량이 6~7% 증가하여 평균 온도상승에 따라 극치강수량 발생 잠재력이 향상 될 것으로 전망되고 있다. 본 연구에서는 온도상승에 따른 극치강수량의 변화를 베이지안 다중분위회귀분석모형을 통해 산정하여 CORDEX 온도자료 기반의 미래 극치강수량을 전망하였다. 본 연구결과 100년 이상 빈도의 강수량은 온도상승에 따라 급격히 증가하는 추세를 확인하였으며, 2100년까지 온도상승을 고려한 최대 극치강수량은 1500mm를 넘을 가능성을 확인하였다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.11
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• pp.1282-1285
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• 1988

A novel temperature difference-to-frequency converter using two resistance temperature detectors (RTD) has been developed. The resistance difference of two RTD is converted into its equivalent inductance to form the resonant circuit of the Colpitts oscillator. The conversion sensitivity of 16 Hz/$^{\circ}C$ and the residual nonlinearity less than 2.15% over the temperature difference range from 35$^{\circ}C$ to 155$^{\circ}C$ are obtained by the prototype converter. The frequency drift of oscillator itself is $\pm$ 0.5Hz. Thus, the minimum detectable temperature difference is estimated to be $\pm$ 0.013$^{\circ}C$. The proposed coverter, except for two RTD, can be fabricated in monolithic IC form.

• Solar Energy
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• v.10 no.3
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• pp.35-45
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• 1990

An analytical equation to estimate the Rankine power cycle efficiency at maximum power for the given mass flow rates of heating and cooling fluids is derived. The accuracy of the result is shown by comparing the analytical values with those calculated one using detailed thermodynamic data. The results indicate that the thermal efficiency at maximum power depends primarily on the initial temperatures of the heating and cooling fluids, and it also depends on the pinch-temperature differences between the working fluid and the heating and cooling fluids. The efficiency at maximum power provides a measure of the power available in a practical Rankine heat engine.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.776-783
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• 1997

Response surface methodology was applied to determine the optimum roasting conditions (roasting temperature and time) for the high-quality Polygonatum odoratum tea which has been roasting with a traditional means. As quality criteria of Polygonatum odoratum tea, water-soluble solids, browning color, total phenolic compounds and electron-donating ability were proportionally increased with increased temperature and time of roasting conditions up to around $145^{\circ}C$ and 55 min, respectively, while they were decreased under the extended-roasting conditions. The optimum roasting temperature and time based on the organoleptic overall acceptability were $146^{\circ}C$ and 52 min, respectively. On the basis of superimposed contour maps for the tea characteristics, the optimum range of roasting conditions were $135{\sim}140^{\circ}C$ and $58{\sim}64$ min. Predicted values at the optimum conditions $(137^{\circ}C,\;60\;min)$ were in good agreement with experimental values.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.981-984
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• 2008

The super tall building above 100 floors is required that each floor's height is more than 4 meters, and each core wall's thickness is more than 60cm. Therefore, for the successive accomplishment of super tall building, the full scale mock-up test was required. The test results are as follows; Real strength of core wall was satisfied with design strength at 28 days regardless of types of strength, and according to the consolidation effect, lower part's strength was a little higher than upper part's strength. Lateral force of HSC was evaluated with max. $4.5ton/m^2$, and hydration temperature of mock-up test was evaluated that maximun heat of central part revealed about $80^{\circ}C$ at 70MPa and $65^{\circ}C$ at 50MPa, and, the difference between inner and outter part revealed about $30^{\circ}C$ at 70MPa and $12^{\circ}C$ at 50MPa. Also, no crack by hydration temperature was not shown on the surface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4375-4380
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• 2015

This study was performed to evaluate a newly proposed heating process of blank, which was used for Crank throw in the diesel engine, and provide design guidelines of heating processes. Non-linear numerical analyses were done using ANSYS program to investigate temperature and thermal stress distributions of blank during heating processes. The heating process consists of two stages; one is a heating stage with 20 hours, and the other is a holding stage with 12 hours, totaling 32-hour heating time. Based on analysis results, it was found that the temperature difference between the center and the surface of blank increased linearly during the heating stage but decreased gradually during the holding stage of heating processes, while max. equivalent stress, $12.5kg/mm^2$, was found at the center of blank after 10-hour heating time. As the guideline of blank heating process, it was recommended to keep the temperature difference between the center and the surface of blank to be within $150^{\circ}C$ when the environment temperature in furnace reaches $650^{\circ}C$ during a heating stage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.602-608
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• 2019

The purpose of this study was to calculate the temperature difference of the sectional elevation according to the asphalt thickness of the steel box girder bridge deck and provide data on the design basis accordingly. Asphalt thicknesses produced four steel box girder model specimens of 0mm, 50mm, 100m and 150mm. In each model, 17 to 23 temperature sensors were attached to upper concrete and steel box girders. Six temperature gauges were selected to compare the temperature difference with Euro codes. The maximum and lowest temperature were calculated at the reference atmospheric temperature of each model, and the temperature difference (slope) was calculated based on this calculation. Four models of temperature difference are presented at each model. The 0mm to 100mm temperature difference models showed a -0.9 to -1.5 degree lower temperature difference compared to the temperature difference of Euro codes at the top of the slab. Overall, the measured temperature difference was found to be between 5.45% and 8.33% compared to the Euro code. The standard error coefficient, which was calculated by multiplying the average temperature with the standard error, was calculated from a range of 2.50 to 2.51 times the average at the top and bottom. It is estimated that the proposed temperature difference model can be used as a basic data when calculating temperature difference criteria for bridges in Korea.