• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.469-472
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• 2023

If temperature management is required in factory or environmental monitoring, temperature can be measured by connecting various sensors wired or wirelessly. Surface acoustic wave sensors measure temperature using changes in acoustic waves on the sensor surface according to temperature, and are useful for wireless networks. In this paper, in order to build a wireless temperature measurement system in the 900 MHz frequency band, the temperature characteristics of the passive SAW sensor were measured, and the analysis and removal of multipath reflection wave effect inside the high temperature chamber were conducted. The resonant frequency of the SAW sensor was measured, and radio transmission/reception and multipath reflected wave removal techniques were proposed in the shielded chamber.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1218-1226
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• 1994

The shock tube is a useful device for investigating shock phenomena, spray combustion, unsteady gas dynamics, etc. Therefore, it is necessary to analyze exactly the flow phenomena in shock tube. In this study, the mechanics of its reflected shock zone has been investigated by using of the one-dimensional gas dynamic theory in order to estimate the transition from initial reflection of shock wave region. Calulation for four kinds of reflected shock tube temperature (i.e. (a) 1388 K (b) 1276 K (c) 1168 K (d) 1073 K) corresponding to the experimental conditions have been carried out sumarized as follows. (1) The qualitative tendency is almost the same as in that conditions in region of reflected wave region. (2) High temperature period (reflected shock wave temperature) $T_{5}$, exists 0-2.65 ms. (3) Transition period from temperature of reflection shock wave is far longer than the calculated one. This principally attributed to the fact that the contact surface is accelerated, also, due to the release of energy by viscoity effect. This apparatus can advance the ignition process of a spray in a ideal condition that involved neither atomization nor turbulent mixing process, where, using a shock tube, a column of droplets freely from atomizer was ignited behind a reflected shock.

• Communications of the Korean Mathematical Society
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• v.10 no.3
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• pp.767-781
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• 1995

In this paper we present computation of a reflected shock in the hypersonic flow of air with chemical reactions. We consider two dimensional steady inviscid hypersonic flow of air around bodies including chemical reaction effects. At a high Mach number, a strong shock is formed in front of the body when a wedge is placed against the flow. In front of the shock, temperature and pressure increase greatly and the flow is in nonequilibrium state. If the shock hits a wall, then a reflected shock is formed in the nonequilibrium flow region. Behind this reflected shock, the temperature and pressure are very high. We carry out the computation of the reflected shock and the flow behind it. The jump conditions at the reflected shock are presented. A technique combining smooth transforms of domain and implicit difference methods is used to overcome numerical difficulties associated with the lack of resolution behind the shock and near the body.

• Proceedings of the KOSOMBE Conference
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• v.1990 no.05
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• pp.67-71
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• 1990

This paper is dedicated to a research on fluorescent temperature-sensor system, which analyses the characteristic of fluorescent material and observes the relation between temperature and time delay of reflected beam from red light through experiment. From the experiment, We know that the reflected be am from flourescent material has some time delay. The intensity of reflected beam is inversly proportional to the temperature around the material.

• Journal of Sasang Constitutional Medicine
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• v.7 no.2
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• pp.265-274
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• 1995

Skin temperatures were tested under the same conditions by using the thermography in order to extract the biological characteristics of the physical constitutional types in according to the Lee's 4 type physical constitutional theory. The subjects of this experiment were 14 ; 5 Macro-Negative subjects, 5 Micro-Negative subjects, 3 Micro-Positive subjects and 1 Macro-Positive subject. All subjects were stimulated with 2.5Hz 30Vpeak-peak pulses for 2 minutes. As the results, in normal prestimulation state the skin temperatures of the trunk in Micro-Positive and Macro-Positive subjects were higher than those of Macro-Negative and Micro-Negative subjects. In Macro-Negative subjects the reflected skin temperature of lever was the highest in the anterior trunk. In Micro-Negative subjects the reflected skin temperature of kidney was the highest in the trunk. In Micro-Positive subjects the reflected skin temperature of stomach was the highest in the trunk.In Macro-Positive subject the reflected skin temperature of lung was the highest in the trunk. In transient poststimulation state, heart rate was decreased in 7 cases among of 10 Macro-Negative ana Micro-Negative subjects, but it was increased in 3 cases among of 4 Micro-Positive and Macro-Positive subjects. And the hand temerature was increased in 8 cases among of 10 Macro-Negative and Micro-Negative subjects, but it was decreased in 3 cases among of 4 Micro-Positive and Macro-Positive subjects.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1264-1264
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• 2001

The affect of surface temperatures of fruits on spectrum which measures actual sugar contents was observed. PLSR was applied to develop the sugar content evaluation system that was not affected by temperature. The reflected spectrum was used at the wavelengths of 654 and 1052nm with the separation distance of 2.5nm. To increase the conformance of a model using unknown samples, let the minimum value of PRESS be an optimum factor. 71 Shingo pears stored in a refrigerator were left in a room temperature for a while and these temperatures and reflected spectrums were measured. Reflected spectrums were measured at the wavelengths of 654 and 1052nm, 3 samples in one second. To measure these at different temperatures, the experiment was repeated hourly and four times. Starting temperatures of 2-3 were increased up to 17. The total number of measured spectrum was 284. To develop a sugar content evaluation system model using measured reflected spectrum, three groups of samples were considered. First group had 51 samples at 14 and second group had 141 samples with lower or higher temperatures than 14. Third group had 155 samples with well distributed temperatures. Other samples were used as validations to ensure the conformance. Measuring the sugar contents of samples with surface temperatures other than 14 were difficult with PLS model I, developed by using a sample temperature of 14. If the sugar contents were compensated using samples' temperatures, results of prediction would be close to the expected results and it would be one of the most important factors to develop this system. PLS models I and II could compensate the temperature but the precision would not come up to the standard. High precision was expected by using samples with wide ranges of temperatures and sugar contents. Both models showed the possibility of an improvement of a sugar content evaluation system disregarding the temperature. For practical use of a system, selecting samples should be done carefully to reduce the effect of the temperature.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.271-274
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• 1997

Skin temperatures, heart rates and skin conductance levels were tested in order to extract the biological characteristics of the physical constitutional types in according to the Lee's 4 type physical constitutional theory. The subjects of this experiment were 14 ; 5 Macro-Negative subjects, 5 Micro-Negative subjects, 3 Micro-Positive subjects and 1 Macro-Positive subject. All subjects were stimulated with 2.5Hz 30V peak-peak pulses for 2 minutes. As the results, in normal prestimulation state the skin temperatures of the trunk in Micro-Positive and Macro-Positive subjects were higher than those of Macro-Negative and Micro-Negative subjects. In Macro-Negative subjects the reflected skin temperature of lever was the highest in the anterior trunk. In Micro-Negative subjects the reflected skin temperature of kidney was the highest in the trunk. In Micro-Positive subjects the reflected skin temperature of stomach was the highest in the trunk. In Macro-Positive subject the reflected skin temperature of lung was the highest in the trunk. In transient poststimulation state, heart rate was decreased in 7 cases among of 10 Macro-Negative and Micro-Negative subjects, but it was iscreased in 3 cases among of 4 Micro-Positive and Macro-Positive subjects. And the hand temperature was increased in 8 cases among of 10 Macro-Negative and Micro-Negative subjects, but it was decreased in 3 cases among of 4 Micro-Positive and Macro-Positive subjects.

• Journal of Sensor Science and Technology
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• v.14 no.3
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• pp.180-185
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• 2005

In this study, a plastic fiber-optic temperature sensor is fabricated using TSCM(thermo sensitive clouding material) which changes its light transmittance with temperature and the characteristics of this sensor are evaluated. The fabricated fiber optic temperature sensor is the reflector type using a Y-coupler. The optimum light source and reflector are decided by measuring the amount of reflected light through TSCM. Also, the optimum distance from the end of sensor to the surface of reflector is determined. Then the relationship between the amount of measured reflected light and the temperature of TSCM is found.

• Journal of Biosystems Engineering
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• v.27 no.2
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• pp.117-124
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• 2002

This research was conducted to develop a method to remove the effect of surface temperature of Shingo pears for sugar content measurement. Sugar content was measured by a near-infrared spectrum analysis technique. Reflected spectrum and sugar content of a pear were used for developing regression models. For the model development, reflected spectrums having wavelengths in the range of 654 to 1,052nm were used. To remove the effect of surface temperature, special sample preparation techniques and partial least square (PLS) regression models were proposed and tested. 71 Shingo pears stored in a cold storage, which had 2$^{\circ}C$ inside temperature, were taken out and left in a room temperature for a while. Temperature and reflected spectrum of each pear was measured. To increase the temperature distribution of samples, temperature and reflected spectrum of each pear was measured four times with one hour twenty minutes interval. During the experiment, temperature of pears increased up to 17 $^{\circ}C$. The total number of measured spectrum was 284. Three groups of spectrum data were formed according to temperature distribution. First group had surface temperature of 14$^{\circ}C$ and total number of 51. Second group consisted of the first and the fourth experiment data which contained the minimum and the maximum temperatures. Third group consisted of 155 data with normal temperature-distribution. The rest data set were used for model evaluation. Results shelved that PLS model I, which was developed by using the first data group, was inadequate for measuring sugar content of pears which had different surface temperatures from 14$^{\circ}C$. After temperature compensation, sugar content predictions became close to the measured values. Since using many data which had wide range of surface temperatures, PLS model II and III were able to predict sugar content of pears without additional temperature compensation. PLS model IV, which included the surface temperatures as an independent variable. showed slightly improved performance(R$^2$=0.73). Performance of the model could be enhanced by using samples with more wide range of temperatures and sugar contents.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.493-501
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• 2013

LED lighting is sensitive because it made by semiconductor. So it has been researched about radiation of heat technologies for a long time. In addition, measurement and assessment a radiation of heat also conducted. It is necessary to get a date of accuracy temperature on the board after LED driven for measuring Junction temperature of the LED Lighting. For this research, we use 5 chip which is 4 W power on top of LED lighting board made by aluminum. Thermal camera effects to emissivity depending on material and property of the surface in LED board because it determines thermal energy which emitted from material surface. it is not only thermal camera has not a standard about emissivity. It has an error of temperature when emissivity was measured by thermal camera. we confirmed that emissivity and reflected temperature depending on color and quality of the surface throughout experiment.