• Title/Summary/Keyword: thermal imaging

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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.

Applying tilt mechanism for high-resolution image acquisition (고해상도 영상 획득을 위한 틸트 메커니즘 적용 기법)

  • Song, Chun-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.12
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    • pp.31-37
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    • 2014
  • In this paper, to compensate the degraded performance in high-resolution infrared sensor due to assembling error, the influence of each component was evaluated through the sensitivity analysis of lens assembly, axis mirror, and detector and also suggested detector tilt mechanism for compensation. 3 detector tilt mechanisms were investigated. The first one is 'Shim plate' method which is applying shim on installing plane. The second one is 'Tilting screw' method that is using tilt screw for adjusting detection plane. The last one is 'Micrometer head' method that is installing micrometer on detection plane and acquiring quantitative data. Based on the investigation result, 'Tilting screw' method was applied due to ease of user control, small volume, and real-time controllability, thereby we could acquire high-resolution infrared images. The research result shows that the tilting mechanism is necessary technology for the implementation of high-resolution infrared imaging system.

Continuous monitoring of the canopy gas exchange of rice and soybean based on the aerodynamic analysis of the plant canopy

  • Tanaka, Yu;Katayama, Hiroto;Kondo, Rintaro;Homma, Koki;Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.60-60
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    • 2017
  • It is important to measure the gas exchange activity of the crops in canopy scale to understand the process of biomass production and yield formation. Thermal imaging of the canopy surface temperature is a powerful tool to detect the gas exchange activity of the crop canopy. The simultaneous measurement of the canopy temperature and the meteorological data enables us to calculate the canopy diffusive conductance ($g_c$) based on the heat flux model (Monteith et al. 1973, Horie et al. 2006). It is, however, difficult to realize the long-term and continuous monitoring of $g_c$ due to the occurrence of the calculation error caused by the fluctuation of the environmental condition. This is partly because the model assumption is too simple to describe the meteorological and aerodynamic conditions of the crop canopy in the field condition. Here we report the novel method of the direct measurement of the aerodynamic resistance ($r_a$) of the crop canopy, which enables us the stable and continuous measurement of the gas exchange capacity of the crop plants. The modified heat balance model shows the improved performance to quantify $g_c$ under the fluctuating meteorological condition in the field. The relationship between $g_c$ and biomass production of rice and soybean varieties is also discussed in the presentation.

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Fabrication of Silicon Window for Low-price Thermal Imaging System (저가형 열영상 시스템을 위한 실리콘 윈도우 제작)

  • Sung, Byung Mok;Jung, Dong Geon;Bang, Soon Jae;Baek, Sun Min;Kong, Seong Ho
    • Journal of Sensor Science and Technology
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    • v.24 no.4
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    • pp.264-269
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    • 2015
  • An infrared (IR) bolometer measures the change of resistance by absorbing incident IR radiation and generates a signal as a function of the radiation intensity. Since a bolometer requires temperature stabilization and light filtering except for the infrared rays, it is essential for the device to be packaged meeting conditions that above mentioned. Minimization of heat loss is needed in order to stabilize temperature of bolometer. Heat loss by conduction or convection requires a medium, so the heat loss will be minimized if the medium is a vacuum. Therefore, vacuum packaging for bolometer is necessary. Another important element in bolometer packaging is germanium (Ge) window, which transmits IR radiation to heat the bolometer. To ensure a complete transmittance of IR light, anti-reflection (AR) coatings are deposited on both sides of the window. Although the transmittance of Ge window is high for IR rays, it is difficult to use frequently in low-price IR bolometer because of its high price. In this paper, we fabricated IR window by utilizing silicon (Si) substrate instead of Ge in order to reduce the cost of bolometer packaging. To enhance the IR transmittance through Si substrate, it is textured using Reactive Ion Etching (RIE). The texturing process of Si substrate is performed along with the change of experimental conditions such as gas ratio, pressure, etching time and RF power.

OPTO-MECHANICAL DESIGN OF THE KASINICS (KASINICS의 광기계부 설계)

  • Yuk, I.S.;Lee, S.L.;Jin, H.;Seon, K.I.;Pak, S.;Lee, D.H.;Nam, U.W.;Moon, B.K.;Cha, S.M.;Han, J.Y.;Kyeong, J.M.;Kim, K.H.;Yang, J.S.
    • Publications of The Korean Astronomical Society
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    • v.20 no.1 s.24
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    • pp.143-149
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    • 2005
  • KASI (Korea Astronomy and Space Science Institute) is developing the near-infrared camera system named KASINICS (KASI Near-Infrared Camera System) which will be installed at the 60cm f/13.5 Ritchey-Chretien telescope of the Sobaeksan Optical Astronomy Observatory (SOAO). The camera system is optimized for JHKL bands and has a 6 arcmin FOV. The optical system consists of two spherical mirrors and a 8-position filter wheel. With the exception for the dewar window, all optical elements are cooled inside cryogenic dewar. Since the Offner system is adopted to prevent thermal noises from outside of the telescope primary mirror, the secondary mirror of the Offner system acts as a cold Lyot stop. The optical performance does not change by temperature variations because the Aluminum mirrors contract and expand homogeneously with its mount. We finished the design and fabrication of the optical parts and are now aligning the optical system. We plan to have a test observation on 2006 January.

Different Types of Active Region EUV Bright Points by Hinode/EIS

  • Lee, Kyoung-Sun;Moon, Yong-Jae;Kim, Su-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.28.2-28.2
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    • 2010
  • We have investigated seven Extreme-Ultraviolet (EUV) bright points in the active region (AR 10926) on 2006 December 2 by the EUV imaging spectrometer (EIS) onboard Hinode spacecraft. We determined their Doppler velocities and non-thermal velocities from 15 EUV spectral lines (log T=4.7-7.2) by fitting each line profile to a Gaussian function. We present the Doppler velocity map as a function of temperature which corresponds to a different height. As a result, these active region bright points show two different types of characteristics. Type 1 bright point shows a systematic increase of Doppler velocity from -68 km/s (blue shift) at log T=4.7 to 27 km/s (red shift) at log T=6.7, while type 2 bright points have Doppler velocities in the range of -20 km/s and 20 km/s. Using MDI magnetograms, we found that only type 1 bright point was associated with the canceling magnetic feature at the rate of $2.4{\times}10^{18}$ Mx/hour. When assuming that these bright points are caused by magnetic reconnection and the Doppler shift indicates reconnection out flow, the pattern of the Doppler shift implies that type 1 bright point should be related to low atmosphere magnetic reconnection. We also determined electron densities from line ratio as well as temperatures from emission measure loci using CHIANTI atomic database. The electron densities of all bright points are comparable to typical values of active regions (log Ne=9.9-10.4). For the temperature analysis, the emission loci plots indicate that these bright points should not be isothermal though background is isothermal. The DEM analysis also show that while the background has a single peak distribution (isothermal), the EUV bright points, double peak distributions.

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A Clinical Study on Adolescent Idiopathic Scoliosis using DITI (DITI를 활용한 청소년기 특발성 척추측만증에 대한 임상적 고찰)

  • Yang, Tae Jun;Jeong, Sang Jun;Kwak, Min Kyung;Jang, Yeo Jin;Hyun, Min Kyoung;Yoon, Tae Kyung;Kim, Ha Na;Wei, Tung Shuen
    • Journal of Acupuncture Research
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    • v.33 no.4
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    • pp.7-14
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    • 2016
  • Objectives : This study was performed to investigate the correlation between Cobb's angle and digital infrared thermographic imaging(DITI) on adolescent idiopathic scoliosis. Methods : A total of 56 patients with adolescent idiopathic scoliosis were classified into four groups according to their Cobb's angle. Four groups were made for each increment of $5^{\circ}$: group $5-10^{\circ}$, group $11-15^{\circ}$, group $16-20^{\circ}$, and group $21-25^{\circ}$. Next we checked thermal differences of 6 acupoints(GB21, BL13, BL15, BL20, BL23, BL26) on DITI and analyzed correlation by SPSS ver. 20.0.0 for windows. Results : 1. The average patient age was approximately 13 years old. 2. The majority of patients complained of pain on both sides. 3. Significant correlation was found between group $11-15^{\circ}$ and group $16-20^{\circ}$, group $16-20^{\circ}$ and group $21-25^{\circ}$ on Simsu(BL15) by Duncan test. Conclusion : Using DITI, Simsu(BL15) is expected to be a valid indicator for the diagnosis and treatment of adolescent idiopathic scoliosis.