• 한국농공학회논문집
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• 제55권6호
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• pp.87-99
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• 2013

For analysis of climate change effects on agriculture, precise agricultural meteorological data are needed to target period and site. In this study, agricultural meteorological data under new climate change scenario (RCP 8.5) are constructed from 2011 to 2099 in 111 agriculture major station suggested by Rural Development Administration (RDA). For verifying constructed data, comparison with field survey data in Suwon shows same trend in maximum temperature, minimum temperature, average temperature, and precipitation in 2011. Also comparison with normals of daily data in 2025, 2055, and 2085 shows reliability of constructed data. In analysis of constructed data, we can calculate sum of days over temperature and under temperature. Results effectively show the change of average temperature in each region and odd days of precipitation which means flood and dry days in target region.

• 설비공학논문집
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• 제21권11호
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• pp.629-635
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• 2009

In this study, fin surface temperature and frost properties, i.e., frost thickness and frost surface temperature on a heat exchanger, were experimentally analyzed with different fin thicknesses, fin sizes and thermal conductivities of fin. As a result, it is found that fin thickness and thermal conductivity of fin should be considered in order to design an efficient heat exchanger fin. Correlations of dimensionless average frost properties were proposed as functions of dimensionless air temperature, dimensionless fin base temperature, dimensionless fin thickness, absolute air humidity, Reynolds number and Fourier number. The correlations predicted well the average frost thickness with a maximum error of 10.5% and frost surface temperature with a maximum difference of $0.89^{\circ}C$, respectively.

• KIEAE Journal
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• 제12권3호
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• pp.83-88
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• 2012

This study analyzed the measured value came out by the field test to verify the surface temperature reduction of the flat roof due to green roof, and confirmed the influence of the green roof based on it, and assessed the possibility of saving structures' energy and reducing $CO_2$ emission of structures. For the actual measurement, the differences of the average atmospheric temperature of the green roof and non-green roof flat roof were $8.67^{\circ}C$ and $0.787^{\circ}C$, and the average floor temperature gaps were $11^{\circ}C$ and $2.008^{\circ}C$ in October and November respectively. It was expected that if it's measured on around summer solstice that the temperature gets higher, the deviation of the surface temperature should be bigger, and it was confirmed that the green roof eventually raises insulating effect of structures and will influence on cooling and heating effects such as energy saving and insulating.

• Journal of the Korean Wood Science and Technology
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• 제23권3호
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• pp.16-22
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• 1995

The profiles of the heating temperature in three water vat temperatures (55, 66 and 77$^{\circ}C$) and the cooling temperature under the average ambient temperature of 3$^{\circ}C$ in 4 and 10cm depths from surface at the center of veneer bolts length showed similar patterns for Japanese larch (Larix leptolepis). Dahurian larch (Larix gmelinei) and Radiata pine (Pinus radiata). The difference of these core temperatures of 10cm depth from surface varied proportionally with the increase of vat temperatures. The average heating time based on final core temperature of 6$^{\circ}C$ lower than vat temperature required about 14.5 hours in vat temperature of 55$^{\circ}C$ and 13.5 hours in vat temperature of 66and 77$^{\circ}C$. Each internal temperature of 4 and 10cm depths from surface started to decrease from the beginning of cooling and after about two hours.

• Journal of Photoscience
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• 제9권2호
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• pp.406-408
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• 2002

In order to know the characteristics of circadian rhythms in core temperature in tropical inhabitants, we measured rectal temperatures every 10 min for 24 hrs in 6 Vietnamese, 20 - 22 yrs (5 males and I females) under natural conditions. Average light intensity was 16000 lx. Ambient temperatures ranged from 33 to 36 oC. These data obtained were compared with those in Japanese setters and the Polish inhabitants. The participants were sitting mostly during wakefulness and lying in bed during sleep. The results obtained are summarized as follows: I) The average maximum value was 37.7 oC, which was significantly higher than in the Japanese and Polish as well. 2) The average minimum value was 36.4 oC, which was also lower. 3) A range of oscillation was 1.3 oC, which was clearly greater than in the people living in the temperate areas. The higher maximum value of core temperature, which was actively regulated under warm temperature, seemed of adaptive significance in order to reduce water consumption. A greater rage of oscillation in tropical Vietnamese people might have ecological significance for efficient acclimatization in the environment with strong light intensity and high ambient temperature, suggesting that the setpoint of core temperature could show a greater range of oscillation.

• 한국환경과학회지
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• 제24권10호
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• pp.1265-1272
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• 2015

To investigate the thermal environment over the summertime asphalt pavements, an automatic weather observation system was installed at a parking lot paved with asphalt to observe various meteorological parameters and surface temperature from July 1 to September 30, 2014. Since the number of rainy days in summer of 2014 particularly after the mid July is more than that of average data, a ratio of daily peak surface temperature above $45^{\circ}C$ was 28% which was lower than the average. The observational data about hourly average surface temperature and various heat balance factors at days where daily peak surface temperature is above $45^{\circ}C$ are as follows: An hour that had the daily maximum temperature was around 15 pm and the value was $49^{\circ}C$ approximately. Net shortwave radiation was the highest at 12pm as $800W/m^2$ and much radiation of $500W/m^2$ was absorbed at the ground between 11am and 17pm. Sensible heat that was delivered from the ground to the atmosphere was evaluated as $200W/m^2$ between 10am and 19pm. underground transfer heat up to $100W/m^2$ was measured as negative from 19pm to the next day 8am, which indicated the lower atmosphere was heated at night.

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.113-123
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• 1998

The present study is to investigate the effect of experimental parameters on the heat transfer characteristics of a spherical capsule storage system using paraffins. N-Tetradecane and mixture of n-Tetradecane 40% and n-Hexadecane 60% were used as paraffins. Water with inorganic material was also tested for the comparison. The experimental parameters were varied for the Reynolds number from 8 to 16 and for the inlet temperature from -7 to 2$^{\circ}C$. Measured local temperatures of spherical capsules in the storage tank were utilized to calculate charging and discharging times, dimensionless thermal storage amount, and the average heat transfer coefficients in the tank. Local charging and discharging times in the storage tank were significantly different. The effect of inlet temperature on charging time was larger than that on discharging time, but the effect of Reynolds number on charging time was smaller than that on discharging time. Charging time of paraffins was faster by 11~72% than that of water with inorganic material, but little difference of discharging time was found among them. The effect of Reynolds number on the dimensionless thermal storage was less during charging process and more during discharging process than the effect of inlet temperature. The effect of the inlet temperature and the Reynolds number on the average heat transfer coefficient of the storage tank was stronger during discharging process than during charging process. The average heat transfer coefficients of the spherical capsule system using paraffins were larger by 40% than those using water.

• 오토저널
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• 제2권1호
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• pp.21-31
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• 1980

Two phase boundary layer equations of laminar filmwise condensation are solved by an approximate integral method under the following condition; saturated vapour flows vertically downward over a cooled surface of uniform temperature, the condensate film is so thin that the inertia and convection terms are neglected. The following conclusions are drawn under the above assumptions. 1. free convection In case of the linear temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$=4/3,(G $r_{l}$ /4.H)$^{1}$4/ and in case of the quadratic profile, numerical results may be expressed as N $u_{m}$=2/1.682,(G $r_{l}$ /H)$^{1}$4/. 2. Forced convection When the temperature profile is assumed to be linear in a liquid film, numerical results fir the average heat transfer coefficients may be expressed as N $u_{m}$=(A, R $e_{l}$ /H)$^{1}$2/. This expression is compared with the experimental results hitherto reported; For theoretical Nusselt number (N $u_{m}$)$_{th}$<2*10$^{4}$, the experimental Nusselt number (N $u_{m}$)$_{exp}$ is on the average larger than theoretical Nusselt number (N $u_{m}$)$_{th}$ by 30%. For (N $u_{m}$)$_{th}$>2*10$^{4}$, experimental Nusselt number (N $u_{m}$)$_{exp}$ is about 1.6 times as large as theoretical Nusselt number (N $u_{m}$)$_{th}$. These large deviation may be caused by the presence of turbulence in the liquid film. In case of the quadratic temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$'=(2,A,Re/H)$^{1}$2/. This formular shows that theoretical Nusselt number (N $u_{m}$)$_{th}$ is larger than experimental Nusselt number (N $u_{m}$)$_{exp}$ by 60%. It is speculated that when the temperature difference between cooled surface and saturated vapour is small, temperature profile in a liquid film is quadratic.quadratic.. quadratic.quadratic..atic..

• Smart Structures and Systems
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• 제20권1호
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• pp.11-22
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• 2017

The long-term effect of ambient temperature on bridge strain is an important and challenging problem. To investigate this issue, one year data of strain and ambient temperature of a long-span cable-stayed bridge is studied in this paper. The measured strain-time history is decomposed into two parts to obtain the strains due to vehicle load and temperature alone. A linear regression model between the temperature and the strain due to temperature is established. It is shown that for every $1^{\circ}C$ increase in temperature, the stress is increased by 0.148 MPa. Furthmore, the extreme value distributions of the strains due to vehicle load, temperature and the combination effect of them during the remaining service period are estimated by the average conditional exceedance rate approach. This approach avoids the problem of declustering of data to ensure independence. The estimated results demonstrate that the 95% quantile of the extreme strain distribution due to temperature is up to $1.488{\times}10^{-4}$ which is 2.38 times larger than that due to vehicle load. The study also indicates that the estimated extreme strain can reflect the long-term effect of temperature on bridge strain state, which has reference significance for the reliability estimation and safety assessment.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제2호
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• pp.120-129
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• 2004

Urban stream restoration projects can improve water quality, wildlife habitats, urban landscape, outdoor recreation spaces, and urban microclimate. The objectives of this research were to investigate temperature cooling effect of urban streams by using satellite imagery, to evaluate environmental variables related to stream cooling effect, and to estimate the cooling effect of the Cheonggye stream restoration project of Seoul, Korea. Findings of this research can be summarized as follows. First, a method of estimating temperature distribution around urban streams by using satellite imagery was developed. Scatter plots of distance from stream edges and average temperature obtained through multiple buffering were used for the estimation. Second, urban temperature cooling effect of streams was estimated by comparing background temperature and temperature of each buffer zone. Third, environmental factors affecting stream cooling effect were also identified. Fourth, the temperature cooling effect of the restoration project was estimated based on three scenarios. An estimated cooling effect based on the average cooling effect of existing tributaries showed the most significant effect; $2.0^{\circ}C$ lower than the present level at the edge of the renovated stream. It was estimated that the temperature of the same area would be $1.4^{\circ}C$ cooler than the present level if the cooling effect of the Yangjaechun was used as the bench mark But the effect would be $1.2^{\circ}C$ lower than the present level if environmental variables related to the temperature cooling effect of urban streams were used as the bench mark.