• Title/Summary/Keyword: imaging infrared

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Heart Rate Signal Extraction by Using Finger vein Recognition System (지정맥 인식 시스템을 이용한 심박신호 검출)

  • Bok, Jin Yeong;Suh, Kun Ha;Lee, Eui Chul
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.6
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    • pp.701-709
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    • 2019
  • Recently, heart rate signal, which is one of biological signals, have been used in various fields related to healthcare. Conventionally, most of the proposed heart rate signal detection methods are contact type methods, but there is a problem of discomfort that the subject have to contact with the device. In order to solve the problem, detection study by non-contact method has been progressed recently. The detected heart rate signal can be used for finger vein liveness detection and various application using heart rate. In this paper, we propose a method to obtain heart rate signal by using finger vein imaging system. The proposed method detected the signal from the changes of the brightness value in the time domain of the infrared finger vein images and converted it into the frequency domain using the image processing algorithm. After the conversion, we removed the noise not related to the heart rate signal through band-pass filtering. In order to evaluate the accuracy of the signal, we analyzed the correlation with the signal obtained simultaneously with the finger vein acquisition device and contact type PPG sensor approved by KFDA. As a result, it was possible to confirm that the heart rate signal detected in non-contact method through the finger vein image coincides with the waveform of actual heart rate signal.

Reduction of VOCs and the Antibacterial Effect of a Visible-Light Responsive Polydopamine (PDA) Layer-TiO2 on Glass Fiber Fabric (Polydopamine (PDA)-TiO2 코팅 유리섬유 직물을 이용한 VOCs의 저감 성능 및 항균성 연구)

  • Park, Seo-Hyun;Choi, Yein;Lee, Hong Joo;Park, Chan-gyu
    • Journal of Environmental Health Sciences
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    • v.47 no.6
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    • pp.540-547
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    • 2021
  • Background: Indoor air pollutants are caused by a number of factors, such as coming in from the outside or being generated by internal activities. Typical indoor air pollutants include nitrogen dioxide and carbon monoxide from household items such as heating appliances and volatile organic compounds from building materials. In addition there is carbon dioxide from human breathing and bacteria from speaking, coughing, and sneezing. Objectives: According to recent research results, most indoor air pollution is known to be greatly affected by internal factors such as burning (biomass for cooking) and various pollutants. These pollutants can have a fatal effect on the human body due to a lack of ventilation facilities. Methods: We fabricated a polydopamine (PDA) layer with Ti substrates as a coating on supported glass fiber fabric to enhance its photo-activity. The PDA layer with TiO2 was covalently attached to glass fiber fabric using the drop-casting method. The roughness and functional groups of the surface of the Ti substrate/PDA coated glass fiber fabric were verified through infrared imaging microscopy and field emission scanning electron microscopy (FE-SEM). The obtained hybrid Ti substrate/PDA coated glass fiber fabric was investigated for photocatalytic activity by the removal of ammonia and an epidermal Staphylococcus aureus reduction test with lamp (250 nm, 405 nm wavelength) at 24℃. Results: Antibacterial properties were found to reduce epidermal staphylococcus aureus in the Ti substrate/PDA coated glass fiber fabric under 405 nm after three hours. In addition, the Ti substrate/PDA coated glass fiber fabric of VOC reduction rate for ammonia was 50% under 405 nm after 30 min. Conclusions: An electron-hole pair due to photoexcitation is generated in the PDA layer and transferred to the conduction band of TiO2. This generates a superoxide radical that degrades ammonia and removes epidermal Staphylococcus aureus.

Forest Fire Area Extraction Method Using VIIRS (VIIRS를 활용한 산불 피해 범위 추출 방법 연구)

  • Chae, Hanseong;Ahn, Jaeseong;Choi, Jinmu
    • Korean Journal of Remote Sensing
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    • v.38 no.5_2
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    • pp.669-683
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    • 2022
  • The frequency and damage of forest fires have tended to increase over the past 20 years. In order to effectively respond to forest fires, information on forest fire damage should be well managed. However, information on the extent of forest fire damage is not well managed. This study attempted to present a method that extracting information on the area of forest fire in real time and quasi-real-time using visible infrared imaging radiometer suite (VIIRS) images. VIIRS data observing the Korean Peninsula were obtained and visualized at the time of the East Coast forest fire in March 2022. VIIRS images were classified without supervision using iterative self-organizing data analysis (ISODATA) algorithm. The results were reclassified using the relationship between the burned area and the location of the flame to extract the extent of forest fire. The final results were compared with verification and comparison data. As a result of the comparison, in the case of large forest fires, it was found that classifying and extracting VIIRS images was more accurate than estimating them through forest fire occurrence data. This method can be used to create spatial data for forest fire management. Furthermore, if this research method is automated, it is expected that daily forest fire damage monitoring based on VIIRS will be possible.

Error Analysis of Three Types of Satellite-observed Surface Skin Temperatures in the Sea Ice Region of the Northern Hemisphere (북반구 해빙 지역에서 세 종류 위성관측 표면온도에 대한 오차분석)

  • Kang, Hee-Jung;Yoo, Jung-Moon
    • Journal of the Korean earth science society
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    • v.36 no.2
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    • pp.139-157
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    • 2015
  • We investigated the relative errors of satellite-observed Surface Skin Temperature (SST) data caused by sea ice in the northern hemispheric ocean ($30-90^{\circ}N$) during April 16-24, 2003-2014 by intercomparing MODerate Resolution Imaging Spectroradiometer (MODIS) Ice Surface Temperature (IST) data with two types of Atmospheric Infrared Sounder (AIRS) SST data including one with the AIRS/Advanced Microwave Sounding Unit-A (AMSU) and the other with 'AIRS only'. The MODIS temperatures, compared to the AIRS/AMSU, were systematically up to ~1.6 K high near the sea ice boundaries but up to ~2 K low in the sea ice regions. The main reason of the difference of skin temperatures is that the MODIS algorithm used infrared channels for the sea ice detection (i.e., surface classification), while microwave channels were additionally utilized in the AIRS/AMSU. The 'AIRS only' algorithm has been developed from NASA's Goddard Space Flight Center (NASA/GSFC) to prepare for the degradation of AMSU-A by revising part of the AIRS/AMSU algorithm. The SST of 'AIRS only' compared to AIRS/AMSU showed a bias of 0.13 K with RMSE of 0.55 K over the $30-90^{\circ}N$ region. The difference between AIRS/AMSU and 'AIRS only' was larger over the sea ice boundary than in other regions because the 'AIRS only' algorithm utilized the GCM temperature product (NOAA Global Forecast System) over seasonally-varying frozen oceans instead of the AMSU microwave data. Three kinds of the skin temperatures consistently showed significant warming trends ($0.23-0.28Kyr^{-1}$) in the latitude band of $70-80^{\circ}N$. The systematic disagreement among the skin temperatures could affect the discrepancies of their trends in the same direction of either warming or cooling.

Improvement of infrared channel emissivity data in COMS observation area from recent MODIS data(2009-2012) (최근 MODIS 자료(2009-2012)를 이용한 천리안 관측 지역의 적외채널 방출률 자료 개선)

  • Park, Ki-Hong;Suh, Myoung-Seok
    • Korean Journal of Remote Sensing
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    • v.30 no.1
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    • pp.109-126
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    • 2014
  • We improved the Land Surface Emissivity (LSE) data (Kongju National University LSE v.2: KNULSE_v2) over the Communication, Ocean and Meteorological Satellite (COMS) observation region using recent(2009-2012) Moderate Resolution Imaging Spectroradiometer (MODIS) data. The surface emissivity was derived using the Vegetation Cover Method (VCM) based on the assumption that the pixel is only composed of ground and vegetation. The main issues addressed in this study are as follows: 1) the impacts of snow cover are included using Normalized Difference Snow Index (NDSI) data, 2) the number of channels is extended from two (11, 12 ${\mu}m$) to four channels (3.7, 8.7, 11, 12 ${\mu}m$), 3) the land cover map data is also updated using the optimized remapping of the five state-of-the-art land cover maps, and 4) the latest look-up table for the emissivity of land surface according to the land cover is used. The updated emissivity data showed a strong seasonal variation with high and low values for the summer and winter, respectively. However, the surface emissivity over the desert or evergreen tree areas showed a relatively weak seasonal variation irrespective of the channels. The snow cover generally increases the emissivity of 3.7, 8.7, and 11 ${\mu}m$ but decreases that of 12 ${\mu}m$. As the results show, the pattern correlation between the updated emissivity data and the MODIS LSE data is clearly increased for the winter season, in particular, the 11 ${\mu}m$. However, the differences between the two emissivity data are slightly increased with a maximum increase in the 3.7 ${\mu}m$. The emissivity data updated in this study can be used for the improvement of accuracy of land surface temperature derived from the infrared channel data of COMS.

An Analysis Method on Injury Symptoms Utilizing Infrared Thermal Imaging under the Freezing Stress of Hedera helix L. (헤데라 헬릭스 식물의 적외선 열영상에 의한 저온 및 한풍피해에 관한 연구)

  • Seong, Bu-Geun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.6
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    • pp.173-179
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    • 2012
  • The experiments, which analyze the injury symptoms and diagnose growth conditions utilizing IRVT and analyzing each parts of H. helix L., had been held under a low temperature. Greenhouse and outdoor growing Genus hedera had been prepared and compared with each Genus hedera's peak and bottom leaves' surface temperature under the experimental categories $-6^{\circ}C$ and $-12^{\circ}C$. As results, analyzing the surface thermal property of peak part leaves' of outdoor growing Genus hedera, at experimental categories $-6^{\circ}C$, $-12^{\circ}C$ were ranged from $-2^{\circ}C{\sim}-7^{\circ}C$ and $-2^{\circ}C{\sim}-15^{\circ}C$. On the other hand, the surface thermal property of bottom part leaves at experimental categories $-6^{\circ}C$, $-12^{\circ}C$ were ranged $-2^{\circ}C{\sim}-11^{\circ}C$ and $-1^{\circ}C{\sim}-12^{\circ}C$. It appears that the thermal properties of leaves' surface on $-6^{\circ}C$ peaks and $-12^{\circ}C$ bottoms were more broadband than bottoms and peaks. It means that the peaks were more sensitive than bottoms, as like $-2^{\circ}C{\sim}-15^{\circ}C$, $-1{\sim}-12^{\circ}C$. Moreover, as similar results had seen to leaves surface temperature added to cold wind conditions. How the cold wind damaged the outdoor growing Genus hedera, analyzed the surface thermal property by IRVT data under $0^{\circ}C$, $-2^{\circ}C$, $-4^{\circ}C$ condition, it resulted to $-6.2^{\circ}C$, $-6.8^{\circ}C$, $-7.5^{\circ}C$. It appeared more $3.5{\sim}6.2^{\circ}C$ low temperature than experimental setting point. In addition, each parts thurmal property of peaks and bottoms was not similar, it referred to each parts' sensitivities of low temperature were different on the peak and bottom leaves surface temperature.

A Study on Real-Time Defect Detection Using Ultrasound Excited Thermography (초음파 서모그라피를 이용한 실시간 결함 검출에 대한 연구)

  • Cho, Jai-Wan;Seo, Yong-Chil;Jung, Seung-Ho;Jung, Hyun-Kyu;Kim, Seung-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.4
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    • pp.211-219
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    • 2006
  • The UET(ultrasound excited thermography) for the ,eat-time diagnostics of the object employs an infrared camera to image defects of the surface and subsurface which are locally heated using high-frequency putted ultrasonic excitation. The dissipation of high-power ultrasonic energy around the feces of the defects causes an increase In temperature. The defect's image appears as a hot spot (bright IR source) within a dark background field. The UET for nondestructive diagnostic and evaluation is based on the image analysis of the hot spot as a local response to ultrasonic excited heat deposition. In this paper the applicability of VET for fast imaging of defect is described. The ultrasonic energy is injected into the sample through a transducer in the vertical and horizontal directions respectively. The voltage applied to the transducer is measured by digital oscilloscope, and the waveform are compared. Measurements were performed on four kinds of materials: SUS fatigue crack specimen(thickness 14mm), PCB plate(1.8 mm), CFRP plate(3 mm) and Inconel 600 plate (1 mm). A high power ultrasonic energy with pulse durations of 250ms Is injected into the samples in the horizontal and vertical directions respectively The obtained experimental result reveals that the dissipation loss of the ultrasonic energy In the vertical injection is less than that in the horizontal direction. In the cafe or PCB, CFRP, the size of hot spot in the vortical injection if larger than that in horizontal direction. Duration time of the hot spot in the vertical direction is three times as long as that in the horizontal direction. In the case of Inconel 600 plate and SUS sample, the hot spot in the horizontal injection was detected faster than that in the vertical direction

THE LUMINOSITY-LINEWIDTH RELATION AS A PROBE OF THE EVOLUTION OF FIELD GALAXIES

  • GUHATHAKURTA PURAGRA;ING KRISTINE;RIX HANS-WALTER;COLLESS MATTHEW;WILLIAMS TED
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.63-64
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    • 1996
  • The nature of distant faint blue field galaxies remains a mystery, despite the fact that much attention has been devoted to this subject in the last decade. Galaxy counts, particularly those in the optical and near ultraviolet bandpasses, have been demonstrated to be well in excess of those expected in the 'no-evolution' scenario. This has usually been taken to imply that galaxies were brighter in the past, presumably due to a higher rate of star formation. More recently, redshift surveys of galaxies as faint as B$\~$24 have shown that the mean redshift of faint blue galaxies is lower than that predicted by standard evolutionary models (de-signed to fit the galaxy counts). The galaxy number count data and redshift data suggest that evolutionary effects are most prominent at the faint end of the galaxy luminosity function. While these data constrain the form of evolution of the overall luminosity function, they do not constrain evolution in individual galaxies. We are carrying out a series of observations as part of a long-term program aimed at a better understanding of the nature and amount of luminosity evolution in individual galaxies. Our study uses the luminosity-linewidth relation (Tully-Fisher relation) for disk galaxies as a tool to study luminosity evolution. Several studies of a related nature are being carried out by other groups. A specific experiment to test a 'no-evolution' hypothesis is presented here. We have used the AUTOFIB multifibre spectro-graph on the 4-metre Anglo-Australian Telescope (AAT) and the Rutgers Fabry-Perot imager on the Cerro Tolalo lnteramerican Observatory (CTIO) 4-metre tele-scope to measure the internal kinematics of a representative sample of faint blue field galaxies in the red-shift range z = 0.15-0.4. The emission line profiles of [OII] and [OIII] in a typical sample galaxy are significantly broader than the instrumental resolution (100-120 km $s^{-l}$), and it is possible to make a reliable de-termination of the linewidth. Detailed and realistic simulations based on the properties of nearby, low-luminosity spirals are used to convert the measured linewidth into an estimate of the characteristic rotation speed, making statistical corrections for the effects of inclination, non-uniform distribution of ionized gas, rotation curve shape, finite fibre aperture, etc.. The (corrected) mean characteristic rotation speed for our distant galaxy sample is compared to the mean rotation speed of local galaxies of comparable blue luminosity and colour. The typical galaxy in our distant sample has a B-band luminosity of about 0.25 L$\ast$ and a colour that corresponds to the Sb-Sd/Im range of Hub-ble types. Details of the AUTOFIB fibre spectroscopic study are described by Rix et al. (1996). Follow-up deep near infrared imaging with the 10-metre Keck tele-scope+ NIRC combination and high angular resolution imaging with the Hubble Space Telescope's WFPC2 are being used to determine the structural and orientation parameters of galaxies on an individual basis. This information is being combined with the spatially resolved CTIO Fabry-Perot data to study the internal kinematics of distant galaxies (Ing et al. 1996). The two main questions addressed by these (preliminary studies) are: 1. Do galaxies of a given luminosity and colour have the same characteristic rotation speed in the distant and local Universe? The distant galaxies in our AUTOFIB sample have a mean characteristic rotation speed of $\~$70 km $s^{-l}$ after correction for measurement bias (Fig. 1); this is inconsistent with the characteristic rotation speed of local galaxies of comparable photometric proper-ties (105 km $s^{-l}$) at the > $99\%$ significance level (Fig. 2). A straightforward explanation for this discrepancy is that faint blue galaxies were about 1-1.5 mag brighter (in the B band) at z $\~$ 0.25 than their present-day counterparts. 2. What is the nature of the internal kinematics of faint field galaxies? The linewidths of these faint galaxies appear to be dominated by the global disk rotation. The larger galaxies in our sample are about 2"-.5" in diameter so one can get direct insight into the nature of their internal velocity field from the $\~$ I" seeing CTIO Fabry-Perot data. A montage of Fabry-Perot data is shown in Fig. 3. The linewidths are too large (by. $5\sigma$) to be caused by turbulence in giant HII regions.

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Relation between Changes of DITI and Clinical Results according to the Level and Extent of Sympathicotomy in Essential Hyperhidrosis (본태성다한증에서 흉부교감신경의 차단 범위와 부위에 따른 임상결과와 체열변화 사이의 관계)

  • 최순호;임영혁;이삼윤;최종범
    • Journal of Chest Surgery
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    • v.37 no.1
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    • pp.64-71
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    • 2004
  • Background: Video-assisted sympathicotomy is a safe and effective method for the treatment of essential hyperhidrosis with immediate symptomatic improvement. However, this is offset by the occurrence of a high rate of side-effects, such as embarrassing compensatory hyperhidrosis. Therefore, by comparing and assessing the relationship between temperature change measured by DITI (digital infrared thermographic imaging) and clinical results according to the level and extent of sympathicotomy in essential hyperhidrosis. we tried to obtain a more precisely and objectively, the distribution and degree of compensatory sweating by DITI and also for ascertaining the clinical usefulness. Material and Method: From January 2000 to June 2002, the thoracoscopic sympathicotomy was performed in 28 patients suffering from essential hyperhidrosis in Dept. of Thoracic and Cardiovascular Surgery, Wonkwang University Hospital. The patients were divided into four groups, Group I: patients having undergone T2 sympathicotomy, Group II: patients having undergone T3 sympathicotomy, Group III: patients having undergone T3,4 sympathicotomy, and Group IV: patients having undergone T2,3,4 sympathicotomy. The parameters were composed of the satisfaction rate of treatment, the degree of compensatory and plantar sweating, and temperature changes of entire body measured by DITI Result: There was no difference in age and follow-up period among the groups. All of the treated patients obtained satisfactory alleviation of essential hyperhidrosis in immediate postoperative period. However, the rate of long-term satisfaction were 85.8%, 85.8%, 42.9%, and 28.6% in group I, II, III, and IV (p<0.05). More than embarrassing compensatory sweating was present in 14.2%, 14.2%, 57.1%, 71.4% in group I, II, III, and IV (p<0.05) In regard to plantar sweating, decrease in sweating was expressed in each of four groups, but was not significant between groups. An apparent increase of temperature measured by DITI indicated sufficient denervation and predicted long-lasting relief of essential hyperhidrosis and also decrease in temperature of trunk and lower extremity by DITI had correlated well with postoperative satisfaction, and also postoperative compensatory sweating. Conclusion: We suggested that the incidence and degree of compensatory sweating was closely related to the site and the extent of thoracic sympathicotomy. Resection of the lower interganglionic neural fiber of the second thoracic sympathetic ganglion on the third rib is the most practical and minimally invasive treatment than other surgical methods. We were also to anticipated the distribution and degree of compensatory sweating by DITI precisely and objectively and for ascertaining the clinical usefulness.

A Reflectance Normalization Via BRDF Model for the Korean Vegetation using MODIS 250m Data (한반도 식생에 대한 MODIS 250m 자료의 BRDF 효과에 대한 반사도 정규화)

  • Yeom, Jong-Min;Han, Kyung-Soo;Kim, Young-Seup
    • Korean Journal of Remote Sensing
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    • v.21 no.6
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    • pp.445-456
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    • 2005
  • The land surface parameters should be determined with sufficient accuracy, because these play an important role in climate change near the ground. As the surface reflectance presents strong anisotropy, off-nadir viewing results a strong dependency of observations on the Sun - target - sensor geometry. They contribute to the random noise which is produced by surface angular effects. The principal objective of the study is to provide a database of accurate surface reflectance eliminated the angular effects from MODIS 250m reflective channel data over Korea. The MODIS (Moderate Resolution Imaging Spectroradiometer) sensor has provided visible and near infrared channel reflectance at 250m resolution on a daily basis. The successive analytic processing steps were firstly performed on a per-pixel basis to remove cloudy pixels. And for the geometric distortion, the correction process were performed by the nearest neighbor resampling using 2nd-order polynomial obtained from the geolocation information of MODIS Data set. In order to correct the surface anisotropy effects, this paper attempted the semiempirical kernel-driven Bi- directional Reflectance Distribution Function(BRDF) model. The algorithm yields an inversion of the kernel-driven model to the angular components, such as viewing zenith angle, solar zenith angle, viewing azimuth angle, solar azimuth angle from reflectance observed by satellite. First we consider sets of the model observations comprised with a 31-day period to perform the BRDF model. In the next step, Nadir view reflectance normalization is carried out through the modification of the angular components, separated by BRDF model for each spectral band and each pixel. Modeled reflectance values show a good agreement with measured reflectance values and their RMSE(Root Mean Square Error) was totally about 0.01(maximum=0.03). Finally, we provide a normalized surface reflectance database consisted of 36 images for 2001 over Korea.