• Title/Summary/Keyword: Thermal Imaging

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GEOMETRY OF SATELLITE IMAGES - CALIBRATION AND MATHEMATICAL MODELS

  • JACOBSEN KARSTEN
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.182-185
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    • 2005
  • Satellite cameras are calibrated before launch in detail and in general, but it cannot be guaranteed that the geometry is not changing during launch and caused by thermal influence of the sun in the orbit. Modem satellite imaging systems are based on CCD-line sensors. Because of the required high sampling rate the length of used CCD-lines is limited. For reaching a sufficient swath width, some CCD-lines are combined to a longer virtual CCD-line. The images generated by the individual CCD-lines do overlap slightly and so they can be shifted in x- and y-direction in relation to a chosen reference image just based on tie points. For the alignment and difference in scale, control points are required. The resulting virtual image has only negligible errors in areas with very large difference in height caused by the difference in the location of the projection centers. Color images can be related to the joint panchromatic scenes just based on tie points. Pan-sharpened images may show only small color shifts in very mountainous areas and for moving objects. The direct sensor orientation has to be calibrated based on control points. Discrepancies in horizontal shift can only be separated from attitude discrepancies with a good three-dimensional control point distribution. For such a calibration a program based on geometric reconstruction of the sensor orientation is required. The approximations by 3D-affine transformation or direct linear transformation (DL n cannot be used. These methods do have also disadvantages for standard sensor orientation. The image orientation by geometric reconstruction can be improved by self calibration with additional parameters for the analysis and compensation of remaining systematic effects for example caused by a not linear CCD-line. The determined sensor geometry can be used for the generation? of rational polynomial coefficients, describing the sensor geometry by relations of polynomials of the ground coordinates X, Y and Z.

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The Effect of Urban Road Vegetation on a Decrease of Road Surface Temperature (도시도로 녹지의 도로 표면온도 져감 효과에 관한 연구)

  • Cha, Hye-Jin;Lim, Ji-Hyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.3
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    • pp.107-116
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    • 2011
  • One of the major factors which increase urban temperature is roads. This paper is aimed to investigate the effect of urban roadside vegetation on the road surface temperature. For this, surface temperature was measured at 18 spots using the thermal imaging camera in terms of road components including use of roadside land use, roadway, sidewalk, roadside vegetation and vegetation median barrier. The size of the roadside vegetation and related urban road characteristics were also measured. In terms of the effect of roadside vegetation on a decrease in road surface temperature, the roadside land use as a green area or open space was the highest, followed by the size of vegetation median barrier and the size of roadside vegetation. Besides road surroundings, an increase in the green zone such as roadside vegetation and median strip vegetation has a significant impact on lowering road surface temperature. Therefore, a good solution for reducing urban heat island effects would be to increase the area of roadside vegetation and green areas along roads.

Study on the Performance of Infrared Thermal Imaging Light Source for Detection of Impact Defects in CFRP Composite Sandwich Panels

  • Park, Hee-Sang;Choi, Man-Yong;Kwon, Koo-Ahn;Park, Jeong-Hak;Choi, Won-Jae;Jung, Hyun-Chul
    • Journal of the Korean Society for Nondestructive Testing
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    • v.37 no.2
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    • pp.91-98
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    • 2017
  • Recently, composite materials have been mainly used in the main wings, ailerons, and fuselages of aircraft and rotor blades of helicopters. Composite materials used in rapid moving structures are subject to impact by hail, lightning, and bird strike. Such an impact can destroy fiber tissues in the composite materials as well as deform the composite materials, resulting in various problems such as weakened rigidity of the composite structure and penetration of water into tiny cracks. In this study, experiments were conducted using a 2 kW halogen lamp which is most frequently used as a light source, a 2 kW near-infrared lamp, which is used for heating to a high temperature, and a 6 kW xenon flash lamp which emits a large amount of energy for a moment. CFRP composite sandwich panels using Nomex honeycomb core were used as the specimens. Experiments were carried out under impact damages of 1, 4 and 8 J. It was found that the detection of defects was fast when the xenon flash lamp was used. The detection of damaged regions was excellent when the halogen lamp was used. Furthermore, the near-infrared lamp is an effective technology for showing the surface of a test object.

Influence of Eco-Friendly Underwears on Atopic Dermatitis (친환경 속옷이 아토피 피부염에 미치는 영향)

  • Choi, Jung-Hwa;Choi, Mee-Sung
    • Journal of Fashion Business
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    • v.19 no.1
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    • pp.141-150
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    • 2015
  • The present study was undertaken to evaluate effects of eco-friendly underwears(three kinds of natural dying underwears) in patients with atopic dermatitis. We recruited 45 patients with atopic dermatitis admitted to Dongshin Oriental Hospital from August to September 2013. These patients were divided into three groups (A, B and C). Each group include 15 patients and three kinds of natural underwears dyed with polygonum tinctorium, loess, and non-dyed general cotton were given, respectively. We also used SCORAD index and digital infrared thermal imaging to investigate the effects of each eco-friendly underwear in patients with atopic dermatitis. In SCORAD index, Group A after wearing loess-dyed underwears for 4 weeks showed statistically significant reduction to 27.96 (P<0.05) compared to 34.20 before wearing loess-dyed underwears. In Group B after wearing polygonum tinctorium-dyed underwears for 4 weeks, SCORAD index and objective severity assessment were markedly reduced into 22.97 (P<0.01) and 18.17 (P<0.01) compared to 35.95 and 27.89 before wearing polygonum tinctorium.-dyed underwears, respectively. In Group C after wearing general cotton (non-dyed) underwears for 4 weeks, there was statistically no difference in SCORAD index, objective severity assessment and body temperature between before and after wearing general cotton (non-dyed) underwears. Taken together, polygonum tinctorium-dyed underwears used to patients with atopic dermatitis shows significant amelioration in atopic symptoms than loess-dyed underwears as well as general cotton (non-dyed) underwears.

An analysis of Electro-Optical Camera (EOC) on KOMPSAT-1 during mission life of 3 years

  • Baek Hyun-Chul;Yong Sang-Soon;Kim Eun-Kyou;Youn Heong-Sik;Choi Hae-Jin
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.512-514
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    • 2004
  • The Electro-Optical Camera (EOC) is a high spatial resolution, visible imaging sensor which collects visible image data of the earth's sunlit surface and is the primary payload on KOMPSAT-l. The purpose of the EOC payload is to provide high resolution visible imagery data to support cartography of the Korean Peninsula. The EOC is a push broom-scanned sensor which incorporates a single nadir looking telescope. At the nominal altitude of 685Km with the spacecraft in a nadir pointing attitude, the EOC collects data with a ground sample distance of approximately 6.6 meters and a swath width of around 17Km. The EOC is designed to operate with a duty cycle of up to 2 minutes (contiguous) per orbit over the mission lifetime of 3 years with the functions of programmable gain/offset. The EOC has no pointing mechanism of its own. EOC pointing is accomplished by right and left rolling of the spacecraft, as needed. Under nominal operating conditions, the spacecraft can be rolled to an angle in the range from +/- 15 to 30 degrees to support the collection of stereo data. In this paper, the status of EOC such as temperature, dark calibration, cover operation and thermal control is checked and analyzed by continuously monitored state of health (SOH) data and image data during the mission life of 3 years. The aliveness of EOC and operation continuation beyond mission life is confirmed by the results of the analysis.

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Design of 4:1 I$\mathbb{R}$ zoom afocal telescope (원적외선 대역 4 : 1 줌 망원경 광학계 설계)

  • 김현숙;김창우;홍석민
    • Korean Journal of Optics and Photonics
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    • v.9 no.3
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    • pp.134-141
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    • 1998
  • A high performance afocal zoom telescope has been designed to operate in the 7.6${\mu}{\textrm}{m}$ to 10.3${\mu}{\textrm}{m}$ waveband for thermal imaging system. This IR zoom telescope is characterized by using of two movable optical element groups, variator and compensator, with mechanically compensated method and the positioning of these groups is controlled by means of a computerized program. The optical performance over the entire 4:1 zoom range and $\pm$2.31~$\pm$9.36 degrees field of view is near diffraction limit while maintaining a constant F-number. The all refracting surfaces of this system except only one aspheric surface are spherical curvature and the material for the optical elements is selected Ge and ZnSe which is used for correction of chromatic aberration.

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Defect Monitoring of a Wind Turbine Blade Surface by using Surface Wave Damping (표면파 기반의 풍력발전기 블레이드 표면상태 실시간 모니터링에 관한 연구)

  • Kim, Kyung-Hwan;Yang, Young-Jin;Kim, Hyun-Bum;Yang, Hyung-Chan;Lim, Jong-Hwan;Choi, Kyung-Hyun
    • Clean Technology
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    • v.23 no.1
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    • pp.90-94
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    • 2017
  • These days much efforts are being dedicated to wind power as a potential source of renewable energy. To maintain effective and uniform generation of energy, defect preservation of turbine blade is essential because it directly takes effects on the efficiency of power generation. For the effective maintenance, early measurements of blade defects are very important. However, current technologies such as ultrasonic waves and thermal imaging inspection methods are not suitable because of long inspection time and non-real time inspection. To supplement the problems, the study introduced a method for real time defect monitoring of a blade surface based on surface wave technology. We examined the effect of various parameters such as micro-cracks and peelings on the propagation of surface wave.

A Report on 6 cases of Abdominal Obesity using Electroacupuncture Combined with Magnetic Acupuncture (전기와 자기장 복합 침 자극을 활용한 복부비만 치료 6례에 대한 증례 보고)

  • Yun, Gee Won;Lee, Hyun;Kim, Yun Joo;Kang, Jae Hui
    • Journal of Acupuncture Research
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    • v.32 no.4
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    • pp.213-226
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    • 2015
  • Objectives : This study was aimed to show the effect of electroacupuncture combined with magnetic acupuncture on abdominal obesity without patient dieting, exercise or use of herbal medication. Methods : Women over 85 cm in waist circumference were treated with electroacupuncture combined with magnetic acupuncture. Acupuncture points were located at the abdomen ($CV_{12}$, $CV_6$, $ST_{25}$, $ST_{21}$, $SP_{15}$, $SP_{14}$), extremities ($LI_4$, $LI_{11}$, $ST_{36}$, $ST_{44}$) and were stimulated 30 minutes with 2.1~3 Gaus, 500 Hz, tolerable strength. The Interference wave forms were by Whata 153 (Medi Lab, Korea). Two or three treatment sessions per week (five or ten sessions in total) were done. Before treatment, and after the last treatment, we measured waist circumference, hip circumference, waist hip ratio, thickness of abdominal subcutaneous fat, body weight, body mass index, body fat ratio, visceral fat area, free fat mass, body fat mass and skeletal muscle mass. We also measured the subcutaneous temperature of the abdomen($CV_{12}$, $ST_{25}(Rt)$, $ST_{25}(Lt)$, $CV_6$) by using digital infrared thermal imaging(DITI). Results : In this study, significant reductions were shown in waist circumference, hip circumference, thickness of abdominal subcutaneous fat, body weight, body mass index, body fat ratio and body fat mass. There were no significant differences in waist hip ratio, free fat mass or skeletal muscle mass. There were also significant increases of the subcutaneous temperature on $CV_{12}$, $ST_{25}(Rt)$, $ST_{25}(Lt)$. Conclusions : From the above results, electroacupuncture combined with magnetic acupuncture might be an effective treatment for abdominal obesity.

Flight Model Development of the MIRIS, the Main Payload of STSAT-3

  • Han, Won-Yong;Lee, Dae-Hee;Park, Young-Sik;Jeong, Woong-Seob;Moon, Bong-Kon;Park, Kwi-Jong;Park, Sung-Joon;Pyo, Jeong-Hyun;Lee, Duk-Hang;Nam, Uk-Won;Park, Jang-Hyun;Seon, Kwang-Il;Yang, Sun-Choel;Park, Jong-Oh;Rhee, Seung-Wu;Lee, Hyung-Mok;Matsumoto, Toshio
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.65.1-65.1
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    • 2012
  • MIRIS (Multipurpose Infra-Red Imaging System) is the first Korean Infrared Space Telescope developed by KASI (Korea Astronomy and Space Science Institute), and is the main payload of STSAT-3 (Science and Technology Satellite-3). The FM (fight model) of MIRIS has been recently completed, and various performance tests have been made to measure system parameters such as readout noise, system gain, linearity, and dark current. Final thermal-vacumm test of the MIRIS and the vibration test of the electronics box have been performed. Band response tests showed good agreement with the initial design requirements. No significant dark difference was measured within the expected temperature variation range during observation in orbit. Using Pa-alpha band from a uniform source, the readout noise and system gain were measured by mean variance test. To obtain uniform flat image, flat fielding tests were made for each band, and the data will be compared to that obtained in orbit for calibration. The final version of MIRIS FM will be delivered in March, and it will be integrated into the satellite system for the AIT (Assembly Integration, Test) procedure. The launch of MIRIS is expected in November 2012.

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Simultaneous velocity and temperature measurement of thermo-fluid flows by using particle imaging technique (화상처리기법을 이용한 온도장 및 속도장 동시 측정기법 개발)

  • Lee, Sang-Joon;Baek, Seung-Jo;Yoon, Jong-Hwan;Doh, Deog-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.10
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    • pp.3334-3343
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    • 1996
  • A quantitative flow visualization technique was developed to measure velocity and temperature fields simultaneously in a two-dimensional cross section of thermo-fluid flows. Thermochromic liquid crystal(TLC) particles are used as temperature sensor and velocity tracers. Illuminating a thermo-fluid flow with a thin sheet of white light, the reflected colors from the TLC particles in the flow were captured simultaneously by two CCD cameras; a 3-chip CCD color camera for temperature field measurement and a black and white CCD camera for velocity field measurement. Variations of temperature field were measured by using a HSI true color image processing system and TLC solution. The relationship between the hue values of TLC color image and real temperature was obtained and this calibration curve was used to measure the true temperature under the same camera and illumination condition. The velocity field was obtained by using a 2-frame PTV technique using the concept of match-probability to track true velocity vectors from two consecutive image frames. These two techniques were applied at the same time to the unsteady thermal-fluid flow in a Hele-Shaw cell to measure the temperature and velocity field simultaneously and some results are discussed.