• 한국초등과학교육학회지:초등과학교육
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• 제22권1호
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• pp.15-28
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• 2003

The purpose of this study was to explore the relationships between the concept of heat and that of temperature for elementary students. Eight multiple choice type questions with explanation of reasons for selection were developed based on previous researches and the analysis of science curriculum for elementary students. The students of 9, 10, 11 years(n=292) were selected from two elementary schools in Taegu City. The responses of students' multiple choice and their explanations were analysed in each items χ² test used for the relationships between types of heat and temperature conceptions Half of elementary student could discriminate the two terms of heat and temperature, majority of them thought that heat is likely to be hot and temperature is the quantity of heat, which is not based on scientific conception. Elementary students thinkings about heat could be classified with material type of heat and molecular kinematics type. Material type of heat were more popular than with molecular kinematics type, although the latter is increased. Majority of students answered correctly in qualitative questions of mixing of hot and cold water, but about only one third of them answers in quantitative questions. Subtraction of cold temperature from hot temperature was the most popular explanation, even though one-quarter of students summed up the two temperature in quantitative situation of mixing hot and cold waters. Those who thought heat as the molecular kinetic responded more correctly in most difficult questions than those who as the material. Therefore, we concluded that the types of heat conceptions affected the concept formation of temperature.

• 한국조경학회지
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• 제30권4호
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• pp.28-36
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• 2002

The main purpose of this study was to estimate a new regression model to explain the relationship between urban forest and air temperature in summer, 2001. This study consists of two parts: correlation coefficient analysis and regression analysis. According to correlation coefficient analysis, thermal infra-red radiations of the major land use categories found significant difference in each category. However there were no significant relationship between the data (thermal infra-red radiation and NDVI) derived from Landsat-7 ETM+ image and air temperature at Automatic Weather Stations(AWSs). After estimating various regression models for summer air temperature, the final models were chosen. The final regression models consisted of two variables such as forest m and traffic facilities area. The regression models explained over 78% of the variability in air temperatures. The regression models with variables of forest area and traffic facilities area showed that the coefficient of the first variable was even more significant than the second one. However, the negative impact of the traffic facilities area was slightly greater than the positive impact of the forest area. Consequently, the effects of forest area and traffic facilities area were apparent to explain summer air temperature in Seoul. Therefore two policies have the most important implications to mitigate the summer air temperature in Seoul: to expand and to conserve the urban forest; and to change the Oafnc facilities'characteristics. The results from this study are expected to be useful not merely in informing the public that urban forest mitigates summer air temperahne, but in urging the necessity of budgets for trees and managing urban forests. It is recommended that field swey of summer air temperature be Performed for the vadidation of the models. The main purpose of this study was to estimate a new regression model to explain the relationship between urban forest and air temperature in summer, 2001. This study consists of two parts: correlation coefficient analysis and regression analysis. According to correlation coefficient analysis, thermal infra-red radiations of the major land use categories found significant difference in each category. However there were no significant relationship between the data (thermal infra-red radiation and NDVI) derived from Landsat-7 ETM+ image and air temperature at Automatic Weather Stations(AWSs). After estimating various regression models for summer air temperature, the final models were chosen. The final regression models consisted of two variables such as forest m and traffic facilities area. The regression models explained over 78% of the variability in air temperatures. The regression models with variables of forest area and traffic facilities area showed that the coefficient of the first variable was even more significant than the second one. However, the negative impact of the traffic facilities area was slightly greater than the positive impact of the forest area. Consequently, the effects of forest area and traffic facilities area were apparent to explain summer air temperature in Seoul. Therefore two policies have the most important implications to mitigate the summer air temperature in Seoul: to expand and to conserve the urban forest; and to change the traffic facilities'characteristics. The results from this study are expected to be useful not merely in informing the public that urban forest mitigates summer air temperature, but in urging the necessity of budgets for trees and managing urban forests. It is recommended that field survey of summer air temperature be Performed for the vadidation of the models.

• Journal of information and communication convergence engineering
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• 제7권1호
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• pp.62-65
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• 2009

In this paper, the temperature characteristics of full CMOS FLL(frequency locked loop) re analyzed. The FLL circuit is used to generate an output signal that tracks an input efference signal. The locking time of FLL is short compared to PLL(phase locked loop) circuit because the output signal of FLL is synchronized only in frequency. Also the FLL s designed to allow the circuit to be fully integrated. The FLL circuit is composed two VCs, two buffers, a VCO and two frequency dividers. The temperature variation of frequency divider, FVC and buffer cancelled because the circuit structure. is the same and he temperature effect is cancelled by the comparator. Simulation results are shown to illustrate the performance of the designed FLL circuit with temperature.

• 전자공학회논문지D
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• 제35D권5호
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• pp.63-68
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• 1998

The absolute pressure sensor using SDB wafer has been fabricated. the structure of the sensor consists of two wheatstone bridges and a diaphragm. One of the two wheatstone bridges is located on the edge of diaphragm, and the other is located on the center of diaphragm. The diaphragm cavity is sealted in vacuum (~10$^{5}$ Torr) to reduce the effect of temperature due to the vapor in the cavity on the sensitivity of pressure sensor. This is the minor method of temperature compensation method. In this experiment the main compensation method is to use the difference of the two bridge offset voltages. The drift of offset voltage with temperature is reduced by using this method so that temperature charcteristics is improved. In this method the temperature effect in the range of 22~100.deg. C was compensated over 80%.

• 대한기계학회논문집B
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• 제20권9호
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• pp.3007-3014
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• 1996

The instantaneous flame temperature and soot formation and oxidation in a D.I. diesel engine are measured using a two-color method. The proposed method based on the continuous spectral radiation from the soot particles in the flame is applicable to industrial diesel engines without major modifications of their main characteristics. Measurements are performed at one location inside the combustion chamber of a D.I. diesel engine. Effects of different engine speeds and loads on flame temperature and KL factor which is an index of soot concentration were examined. Little temperature change were observed with increasing rpm, while increased with loads. The higher the flame temperature is, the lower the KL factor is.

• 대한기계학회논문집B
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• 제28권9호
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• pp.1124-1132
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• 2004

The inverse problem of determining unknown inlet temperature in thermally developing, hydrodynamically developed two phase laminar flow in a parallel plate duct is considered. The inlet temperature profile is determined by measuring temperature in the flow field. No prior information is needed for the functional form of the inlet temperature profile. The inverse convection problem is solved by minimizing the objective function with regularization method. The conjugate gradient method as iterative method and the Tikhonov regularization method are employed. The effects of the functional form of inlet temperature, the number of measurement points and the measurement errors are investigated. The accuracy and efficiency of these two methods are compared and discussed.

• Journal of Advanced Marine Engineering and Technology
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• 제22권6호
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• pp.782-791
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• 1998

This paper presents a computer simulation of five types of triple effect absorption cycles employ-ing the refrigerant absorbent combinations of NH3/LiNO3 low-pressure type NH3/LiNO3+H2O/LiBr binary two-stage type series flow cycle and two types of parallel flow cycle for H2O/LiBr. The absorption systems is investigated through cycle simulation to obtain the system characteristics with the cooling water inlet temperature approach temperature of absorber loss temperature of absorber and chilled water outlet temperature. The most important characteristic temperature of absorber and chilled water outlet temperature. The most important characteristic of NH3/LiNO3 low-pressure type and a NH3/LINO3+H2O/LiBr binary two-stage type is that it obtains a coefficient of performance higher than the sum of the performance coefficients of its part operating independently. As a result of this analysis the optimum designs and operating conditions were determined based on the operating conditions and the coefficient of performance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.272-277
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• 1997

The object of this paper is to analyze the surface temperature of RC structures caused by fire. The experimental analysis is undertaken by using following two methods. 1) Simulation to analyze the relationship between the temperature and the condition change for glass wool caused by fire. 2) Temperature-analysis (TG/DTA tests) of RC structures. From the results of the two experimental analysis, it was possible to estimate the temperature of RC concrete structures caused by fire.

• 설비공학논문집
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• 제25권12호
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• pp.674-678
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• 2013

We present a non-invasive technique to the measure temperature distribution in nano-sized porous thin films by means of the two-color laser-induced fluorescence (2-LIF) of rhodamine B. The fluorescence induced by the green line of a mercury lamp with the makeup of optical filters was measured on two separate color bands. They can be selected for their strong difference in the temperature sensitivity of the fluorescence quantum yield. This technique allows for absolute temperature measurements by determining the relative intensities on two adequate spectral bands of the same dye. To measure temperature fields, Silica (SiO2) nanoporous structure with 1-um thickness was constructed on a cover glass, and fluorescent dye was absorbed into these porous thin films. The calibration curves of the fluorescence intensity versus temperature were measured in a temperature range of $10-60^{\circ}C$, and visualization and measurement of the temperature field were performed by taking the intensity distributions from the specimen for the temperature field.

• 태양에너지
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• 제15권1호
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• pp.29-38
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• 1995

본 연구는 $H_2O/LiBr$와 $NH_3/H_2O$계를 사용하는 2단2원 흡수식 사이클의 특성에 관한 연구이다. 이 사이클은 2개의 단효용 사이클로 이루어져 있으며, 저온단의 흡수기와 응축기에서 얻어진 열을 고온단의 증발기에서 이용하는 사이클로서 저온단의 증발기 및 응축기의 온도, 재생기 온도, 열교환 온도차를 파라메터로 하여 계산한 결과 다음과 같은 결론을 얻었다. 2단2원사이클의 성립범위를 확인하였으며 본 계산조건에서 $50{\sim}70^{\circ}C$의 승온폭을 얻을 수 있었다. 또한 $50^{\circ}C$의 난방온도를 얻기위한 최적재생온도는 $105^{\circ}C$, 최대 COP를 얻기위한 저온측사이클의 응축압력은 $16^{\circ}C$, 그리고 이 조건에서 저온측 사이클의 응축압력을 단효용 사이클의 경우보다 낮게 억제하는 것이 가능함을 알았다.