• Title/Summary/Keyword: Infrared Thermometer

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Generation of Land Surface Temperature Orthophoto and Temperature Accuracy Analysis by Land Covers Based on Thermal Infrared Sensor Mounted on Unmanned Aerial Vehicle (무인항공기에 탑재된 열적외선 센서 기반의 지표면 온도 정사영상 제작 및 피복별 온도 정확도 분석)

  • Park, Jin Hwan;Lee, Ki Rim;Lee, Won Hee;Han, You Kyung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.4
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    • pp.263-270
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    • 2018
  • Land surface temperature is known to be an important factor in understanding the interactions of the ground-atmosphere. However, because of the large spatio-temporal variability, regular observation is rarely made. The existing land surface temperature is observed using satellite images, but due to the nature of satellite, it has the limit of long revisit period and low accuracy. In this study, in order to confirm the possibility of replacing land surface temperature observation using satellite imagery, images acquired by TIR (Thermal Infrared) sensor mounted on UAV (Unmanned Aerial Vehicle) are used. The acquired images were transformed from JPEG (Joint Photographic Experts Group) to TIFF (Tagged Image File Format) format and orthophoto was then generated. The DN (Digital Number) value of orthophoto was used to calculate the actual land surface temperature. In order to evaluate the accuracy of the calculated land surface temperature, the land surface temperature was compared with the land surface temperature directly observed with an infrared thermometer at the same time. When comparing the observed land surface temperatures in two ways, the accuracy of all the land covers was below the measure accuracy of the TIR sensor. Therefore, the possibility of replacing the satellite image, which is a conventional land surface temperature observation method, is confirmed by using the TIR sensor mounted on UAV.

Evaluation of Measurement Accuracy for Unmanned Aerial Vehicle-based Land Surface Temperature Depending on Climate and Crop Conditions (기상 조건과 작물 생육상태에 따른 무인기 기반 지표면온도의 관측 정확도 평가)

  • Ryu, Jae-Hyun
    • Korean Journal of Remote Sensing
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    • v.37 no.2
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    • pp.211-220
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    • 2021
  • Land Surface Temperature (LST) is one of the useful parameters to diagnose the growth and development of crop and to detect crop stress. Unmanned Aerial Vehicle (UAV)-based LST (LSTUAV) can be estimated in the regional spatial scale due to miniaturization of thermal infrared camera and development of UAV. Given that meteorological variable, type of instrument, and surface condition can affect the LSTUAV, the evaluation for accuracy of LSTUAV is required. The purpose of this study is to evaluate the accuracy of LSTUAV using LST measured at ground (LSTGround) under various meteorological conditions and growth phases of garlic crop. To evaluate the accuracy of LSTUAV, Relative humidity (RH), absolute humidity (AH), gust, and vegetation index were considered. Root mean square error (RMSE) after minimizing the bias between LSTUAV and LSTGround was 2.565℃ under above 60% of RH, and it was higher than that of 1.82℃ under the below 60% of RH. Therefore, LSTUAV measurement should be conducted under the below 60% of RH. The error depending on the gust and surface conditions was not statistically significant (p-value < 0.05). LSTUAV had reliable accuracy under the wind speed conditions that allow flight and reflected the crop condition. These results help to comprehend the accuracy of LSTUAV and to utilize it in the agriculture field.

Black Body Design and Verification for Non-Uniformity Correction of Imaging Sensor and Uncertainty Analysis (영상센서의 비균일 응답특성 보정을 위한 흑체 설계 및 성능검증과 보정오차 분석)

  • Shin, Somin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.3
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    • pp.240-245
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    • 2013
  • Each pixel of InfraRed(IR) sensor differently responds to IR light as time elapses or the sensor on/off operation is repeated. As a result, the quality of IR sensor image is deteriorated, and therefore NUC(Non-uniformity Correction) is periodically needed for IR sensor. In this paper, in order to perform NUC in the Satellite, on-board V-grooved blackbody is designed with a baffle so that the emissivity of black body is to be higher than 0.995 as well as the temperature deviation is less than $1^{\circ}C$ in the range of the infrared wave length from 3.3 to $5.2{\mu}m$. To check its performance, the emissivity and the surface temperature of the blackbody by TRT(Transfer Reference Thermometer) and IR Micrometer scanner are measured, respectively. From the results, black body design is verified and the uncertainty of NUC is estimated through the measurement results.

A study on the relationship between the thermal properties of rock and the enviroment in underground spaces (암반 열물성과 지하공간 환경분석 연구)

  • Lee, Chang-Woo
    • Tunnel and Underground Space
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    • v.6 no.4
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    • pp.335-341
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    • 1996
  • This fundamental study analyzes the relationship between rock thermal properties and psychrometric properties in underground space and has a ultimate goal to develope technologies for predicting major environmental variables. The study is divided into 2 subjects (1) developement of a basic model for predicting temperature and humidity, (2) analysis of the validity of the model through application to a local underground storage space for military supplies. The basic model is built for the network of tunnel-shaped underground spaces. The model takes into account rock thermal properties and changes in moisture content in the air due to condensation/evaporation on the rock surface. Using lumped-parameter analytical method, heat flux from or to the surrounding rock is calculated and then the psychrometric properties(air quantity, pressure, temperature, humidity) are estimated through network simulation. The model can be utilized regardless of the tunnel type. The study site is a local storage space built in rock, mainly granite gneiss and quartz-porphyry. It is a U-shaped tunnel, 593.5m long and 6x6.5m wide. Relative humidity inside has to be strictly controlled under 55% to avoid erosion of a certain types of supplies stored in 6 chambers with the capacity of 300~1.000 ton. The thermal conductivity varies between 2.734 and 2.779W/m$^{\circ}C$ and the thermal diffusivity is in the range of 1.119 and $1.152{\times}10^{-6}\;m^2/s$ the specific heat between 910 and $920\;J/kg^{\circ}C$. Relative errors of the predicted values of dry/wet temperature and relative humidity are 0.8~3.0%, 0~7.5% and 0~7.0%, respectively. Apparent errors associated with the rock surface temperature seems to be partly due to the intrinsic limitations in the infrared thermometer used in this study.

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Comparison of Tympanic and Axillary Temperatures (고막체온과 액와체온의 비교 연구 - 성인대상자를 중심으로 -)

  • Yea, Jae-Hee;Jo, Hyun-Sook
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.16 no.2
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    • pp.162-170
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    • 2009
  • Purpose: To verify the usability of tympanic temperature measurement for adults, a comparison of tympanic and axillary temperatures was done. Method: The study was conducted during October 2008, and participants were 110 female nursing students. Axillary temperatures were taken with glass mercury thermometers for 5, 7 and 10 minutes. Tympanic temperatures were taken with Infrared Thermometer IRT 4520 on both ears, twice at a 5-second interval. The data were analyzed using the SPSS 12.0 program. Results: In the 1st measurement, the mean for right tympanic temperatures ($0.06^{\circ}C$) and for left ($0.03^{\circ}C$) were significantly higher than the 2nd. A comparison of mean temperatures for right and left, showed that the mean for the left side on the 1st measurement was significantly higher ($0.01^{\circ}C$) than the right. Also the temperature on left side in the 2nd measurement was higher ($0.04^{\circ}C$) than the right 2nd, but not significantly higher. The mean temperature for right and left tympanic on 1 st and 2nd measurements were significantly higher than axilla for 5 minutes ($0.58^{\circ}C$), for 7 minutes ($0.52^{\circ}C$), and for 10 minutes ($0.43^{\circ}C$). The tympanic temperature was the most closely correlated with the axillary temperature at 10 minutes. Conclusion: Findings indicate that measurement of tympanic temperature is a useful alternative to axillary temperature taken for 10 minutes.

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Analysis of Thermal Characteristics for Areas of Musim Stream in Cheongju City (청주시 무심천 주변의 열환경 특성 분석)

  • Park, Jin-Ki;Na, Sang-Il;Park, Jong-Hwa
    • Korean Journal of Agricultural Science
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    • v.37 no.1
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    • pp.81-86
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    • 2010
  • The urban thermal environment can be an important index to detect heat island phenomena and manage it to improve urban life quality. Cheongju is a typical plain-city that main part has been formed and developed in lowland. The Mushim stream crosses the city from south to north. We reviewed the use of thermal remote sensing in stream around areas and the thermal environments, focusing primarily on the Urban Heat Island(UHI) effect. The purpose of this study is to determine the relationship between the stream nearby urban area and the stream cooling effect of UHI. The objectives are to determine the usefulness of KOMPSAT-2 bands MS3 and MS4 for vegetation cover mapping, and the usefulness of LANDSAT TM band 6 in identifying thermal environmental characteristics and UHI. Land Surface Temperatures (LST) are retrieved by single-channel algorithm to study the UHI from the 6th band (thermal infrared band) of LANDSAT TM images and thermal radiance thermometer based on remote sensing method and the LST distribution maps are accomplished according to the retrieval results. There is also comparison of satellite-derived and in situ measured temperature. The results indicated that the LST of urban center is higher than that of suburban area, the temperature of mountain and water are the lowest area, so it is clearly proved that there are obvious UHI effects by stream. The surface temperature distribution of Mushim stream is detected $2^{\circ}C$ lower than urban area.

Evaluation of Skin Microcirculation by Laser Doppler Flowmeter in Healthy Beagle Dogs

  • Kim, Juntaek;Bae, Seulgi;Lee, Keunwoo;OH, Taeho
    • Journal of Veterinary Clinics
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    • v.34 no.4
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    • pp.249-254
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    • 2017
  • The cutaneous microcirculation plays a role in various physiological processes and pathological conditions. Two non-invasive methods were used in this study to obtain reference values for cutaneous microcirculation in intact male beagles. Twenty intact male beagles were used. The experimental environments were standardized. Laser Doppler flowmetry was used to measure cutaneous blood flow, and an infrared thermometer was used to measure cutaneous temperature. The blood flow and temperature were measured from the right side of the subjects at 20 cutaneous sites. Based on the laser Doppler flowmetry, the region with the highest blood flow was the periocular region that with the lowest was the forelimb foot pad. In addition, the standard deviation of the chest wall was the highest while that of the periocular region was the lowest. For skin temperature, the inguinal region had the highest mean skin temperature and the forelimb foot pad had the lowest. The correlation coefficient between the two methods was 0.72. Similar to a previous study, the values derived from repeated measurements at the 20 regions are reproducible and can contribute to research. Compared to the results of a previous study, the temperatures of the two smallest skin regions were the same; however, no specific trend was observed. The correlation coefficient between the two methods was significantly comparable, and this good correlation can reduce their limitations and variables complementarily. In addition to possible use in human studies, accumulated resources on measurements of skin blood flow in the future will potentiate its use in the veterinary medicine field.

Dry Friction Characteristics of Bulk Amorphous Thermal Spray Coating and Amorphous Metallic Matrix Composites (벌크 비정질 용사코팅과 비정질 기지 복합재료의 건조 마찰특성)

  • Jang, Beomtaek;Yi, Seonghoon
    • Tribology and Lubricants
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    • v.30 no.2
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    • pp.108-115
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    • 2014
  • The friction behaviors of bulk amorphous thermal spray coating (BAC) and second phase-reinforced composite coatings using a high velocity oxy-fuel spraying process were investigated using a ball-on-disk test rig that slides against a ceramic ball in an atmospheric environment. The surface temperatures were measured using an infrared thermometer installed 50 mm from the contact surface. The crystallinities of the coating layers were determined using X-ray diffraction. The morphologies of the coating layers and worn surfaces were observed using a scanning electron microscope and energy-dispersive spectroscopy. The results show that the friction behavior of the monolithic amorphous coating was sensitive to the testing conditions. Under lower than normal loads, a low and stable friction coefficient of about 0.1 was observed, whereas under a higher relative load, a high and unstable friction coefficient of greater than 0.3 was obtained with an instant temperature increase. For the composite coatings, a sudden increase in friction coefficient did not occur, i.e., the transition region did not exist and during the friction test, a gradual increase occurred only after a significant delay. The BAC morphology observations indicate that viscous plastic flow was generated with low loads, but severe surface damage (i.e., tearing) occurred at high loads. For composite coatings, a relatively smooth surface was observed on the worn surface for all applied loads.

Clinical Trial for the Heat-Rising Action of Ginseng and Cultivated Wild Ginseng to The Subject Diagnosed as Heat Pattern by Cold-Heat Patternization (한열변증을 통한 열증 대상자에 산양삼과 재배인삼의 상부 승열 작용에 대한 인체적용시험)

  • Yoo, Su-Jeong;Ko, Sung-Kwon;Kim, Hyeong-Jun
    • The Journal of Korean Obstetrics and Gynecology
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    • v.30 no.4
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    • pp.45-58
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    • 2017
  • Objectives: The aim of this trial is to investigate the effect of Ginseng and Wild Cultivated Ginseng to Heat pattern subject. Methods: Eighty-nine Subjects were diagnosed as heat pattern by Cold-Heat Patternization and divided into Ginseng group (n=30), Wild Cultivated Ginseng group (n=31) and Placebo group (n=28) in their 1 st visit. In each visit, The researchers measured the subject's facial temperature using the infrared thermometer (Testo 835-T1). After that, The subjects were asked to mark the current score of flushing on the Visual Analogue Scale (VAS) and to complete the Chalder-Fatigue Scale (CFS) in each visit. The subjects took the test drug for one week and returned the remaining drug on the 2nd visit. The trial result was analyzed with one-way ANOVA using SPSS for Windows version 18. Results: 1. Systolic blood pressure was significantly lower in the Ginseng group and Wild Cultivated Ginseng group than in the control group (p=0.021). 2. There was no significant difference in facial temperature between each groups. 3. The current score of flushing showed the greatest decrease in the Ginseng group compared to the other groups but there was no significant difference (p=0.205). 4. The score of Chalder-Fatigue Scale was decreased in all groups but not statistically significant (p=0.180). Conclusions: This study showed that taking Ginseng extract and Wild Cultivated Ginseng extract do not affect to heat-rising reaction to the subjects diagnosed as heat pattern.

Diagnostic Accuracy of Temporal Artery Temperatures Measurements (이마 체온의 진단정확도)

  • Park, Yumi;Jung, Wonje;Oh, Hyun;Kim, Yoonkyoung;Kim, Eunyoung;Kim, Mikyung;Shin, Heeyeon
    • Journal of Korean Clinical Nursing Research
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    • v.24 no.2
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    • pp.227-234
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    • 2018
  • Purpose: This study compared the temporal artery temperature (TAT) measured by infrared temporal artery thermometers to the axillary temperature (AT) measured by standard mercury-in-glass thermometers, and evaluated accuracy of the TAT measurement for clinical practice. Methods: A total of 247 adult inpatients in general wards in a tertiary medical center located in Seoul participated in the study. The TAT was measured within one minute after the AT measurement. Data were analyzed using descriptive statistics, paired t-test, Pearson correlation coefficient, linear regression, and the Bland-Altman plot. Results: There was a significant difference in mean temperature between AT and TAT, $36.89^{\circ}C$ (SD=0.70) versus $37.35^{\circ}C$ (SD=0.72). The Bland-Altman plots demonstrated the difference between the AT and TAT as -1.29 to +0.33. The specificity and sensitivity of the TAT in detecting fever were high. The positive predictive values were 57.5% and 71.0% when the AT were higher than $38.0^{\circ}C$ and the TAT fever cutoff levels were $38.0^{\circ}C$ and $38.3^{\circ}C$ respectively. Conclusion: TAT and AT were highly correlated and agreeable, indicating that TAT is as accurate as AT. The findings suggested that TAT measurement can be used in clinical practice. For accurate communication between medical personnel, medical institutions need to provide guidelines for temperature measurement, especially for the use of thermometer and measurement sites.