• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.27-34
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• 2005

We analyze in detail axially symmetric theoretical study for the photothermal pulsed radiometry of a cylindrical model. The theoretical solutions describe the transient infrared radiation from the sample heated by short-duration pulsed heating. In the conventional transmission radiometry technique, the excitation source and the detector are on opposite sides of the sample, otherwise in the new single ended radiometry technique, the excitation source and the detector are on same sides of the sample. The analytical solution described for photothermal radiometry in this study would not need to cut or polish samples to measure the thermal diffusivity. Therefore the radial area and axial thickness of samples are not limited. The effects of excitation pulse duration and the area of heat source are discussed.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.357-364
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• 2006

Microwave Radiometry is the spectral measurement of eleclromagnetic radiation at frequency bands in the microwave region. One particular application of Microwave Radiometry is for analyzing temperature difffrentials of inside of human body to detect and diagnose pathologic conditions in which the temperature differentials are related with the symptoms of certain diseases. To accomplish this aim, we propose a new calibration method for estimating subcutaneous temperature by Microwave Radiometer and we also suggest a tumor-imitator phantom structure for simulating heat diffusion propagated by tissues around tumors to evaluate the discernment of brighuless temperature difffrentials.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.845-847
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• 2000

깊은 생체 조직에서 전자기 에너지의 일부가 피부로 전달되는데, 이때 생체 내부에서 피부로 전달되는 전자기 에너지의 세기는, 주파수 대역과 전자기파를 흡수, 반사, 투과시키는 인체의 매질에 따라 다르다. Microwave Radiometry는 인체 내부 조직에서 방출되는 1-6 GHz 대역의 전자기 에너지 일부를 피부 표면에서 측정하여 일정한 체적내의 인체 내부 온도 평균온도를 추정하는 방법이다. 이러한 Radiometry로 암이나 종양 등의 이상 조직을 진단하는 의학적 가설은, 암이 진행시 악성 종양의 세포의 신진대사가 정상 세포보다 활발하게 되고 또한 종양 세포 주위로 혈액의 유입이 증가하게되어, 주위의 정상 세포 보다 열을 보다 더 방출하는 데 있다. 이때 발생된 열은 일정한 주파수 대역의 마이크로파 에너지를 방출하게 되고, 이에 Radiometry로 인체에 무해하고(passive), 비침습적(non-invasive), 방사능의 영향이 없는 (non-ionizing) 방법으로 인체 내부에서 전달되는 전자기 에너지 강도를 측정하여 종양 부위와 주위 정상부위의 온도 차이를 추정 의학진단에 응용할 수 있다. 본 논문에서는 이러한 Microwave Radiometry의 의학적 응용과 생리학적 특성을 고려한 인체모델용 팬텀에 대하여 살펴본다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1347-1351
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• 2006

Microwave radiometry, as a non-invasive technique which doesn't pierce inside human and can measure the temperature, is to diagnose early the disease or abnormality by measuring the temperature inside human. In this paper, as an antenna for measuring human radiometric signals, we simulated and measured a dipole-type antenna with circular loops. As a measured result has a ultra wideband characteristic of $130%(0.8\sim3.8GHz)\;for\;511\leq-10dB$, it is considered to be suitable to detect the position and size of human tissue having various diseases.

• Journal of the Korean Physical Society
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• v.73 no.12
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• pp.1821-1826
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• 2018

Uniformity is a key feature of state-of-the-art infrared focal planed array (IRFPA) and infrared imaging system. Unlike traditional infrared telescope facility, a ground-based infrared radiant characteristics measurement system with an IRFPA not only provides a series of high signal-to-noise ratio (SNR) infrared image but also ensures the validity of radiant measurement data. Normally, a long integration time tends to produce a high SNR infrared image for infrared radiant characteristics radiometry system. In view of the variability of and uncertainty in the measured target's energy, the operation of switching the integration time and attenuators usually guarantees the guality of the infrared radiation measurement data obtainted during the infrared radiant characteristics radiometry process. Non-uniformity correction (NUC) coefficients in a given integration time are often applied to a specified integration time. If the integration time is switched, the SNR for the infrared imaging will degenerate rapidly. Considering the effect of the SNR for the infrared image and the infrared radiant characteristics radiometry above, we propose a-wide-dynamic-range NUC algorithm. In addition, this essasy derives and establishes the mathematical modal of the algorithm in detail. Then, we conduct verification experiments by using a ground-based MWIR(Mid-wave Infared) radiant characteristics radiometry system with an Ø400 mm aperture. The experimental results obtained using the proposed algorithm and the traditional algorithm for different integration time are compared. The statistical data shows that the average non-uniformity for the proposed algorithm decreased from 0.77% to 0.21% at 2.5 ms and from 1.33% to 0.26% at 5.5 ms. The testing results demonstrate that the usage of suggested algorithm can improve infrared imaging quality and radiation measurement accuracy.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.305-308
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• 2008

The goal of this study is to retrieve ASTER thermal radiometry using a radiative transfer model. The MODTRAN is used for the model because it is easy to use with high spatial resolution and it is possible to specify input parameters such as profiles of temperature, water vapor density, ozone, aerosols and any of the other gasses. Most of parameters such as temperature and water vapor profiles were obtained from the Terra MODIS. The selected ASTER scene images land and coastal area. The surface radiance of ASTER TIR bands were retrieved by MODTRAN and extracted atmospheric profiles from MOD07 and US standard 76 models. Radiance estimated using MOD07 data was systematically lower by about 0.5-1.0 $W/m^2$ sr ${\mu}m$ than that by US standard 76 model between the two cases.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.261-266
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• 1997

Nonevasive multifrequency microwave radiometry using coaxial waveguide antenna has been investigated for a homogeneous and four layer human body model. The coupling between coaxial waveguide antenna and a biological object was analyzed by use of the finite-difference time-domain(FDTD) method to obtain the absorbed power patterns in the media. The object studied in this paper was a homogeneous and four-layered lossy medium. The specific absorption rates(SAR) distribution which was corresponding to the temperature distribution was calculated in each region by use of the steady-state response in FDTD method. The SAR pattern of 1.2GHz was compared with that of 1.8GHz.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.3 no.3
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• pp.14-24
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• 1989

• Journal of the Korea Society of Computer and Information
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• v.20 no.4
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• pp.57-67
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• 2015

The concept of detection and classification of objects based on infrared camera is widely applied to military applications. While the object detection technology using infrared images has long been researched and the latest one can detect the object in sub-pixel, the object classification technology still needs more research. In this paper, we present object classification method based on measured radiant intensity of objects such as target, artillery, and missile using infrared camera. The suggested classification method was verified by radiant intensity measuring experiment using black body. Also, possible measuring errors were compensated by modelling-based correction for accurate radiant intensity measure. After measuring radiation of object, the model of radiant intensity is standardized based on theoretical background. Based on this research, the standardized model can be applied to the object classification by comparing with the actual measured radiant intensity of target, artillery, and missile.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.2
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• pp.235-247
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• 2006

Aerosol indirect radiative forcing of climate change is considered the most uncertain forcing of climate change over the industrial period, despite numerous studies demonstrating such modification of cloud properties and several studies quantifying resulting changes in shortwave radiative fluxes. Detection of this effect is made difficult by the large inherent variability in cloud liquid water path (LWP): the dominant controlling influence of LWP on optical depth and albedo masks any aerosol influences. Here we have used ground-based remote sensing of cloud optical depth (${\tau}_c$) by narrowband radiometry and LWP by microwave radiometry to determine the dependence of optical depth on LWP, thereby permitting examination of aerosol influence. The method is limited to complete overcast conditions with liquid-phase single layer clouds, as determined mainly by millimeter wave cloud radar. The results demonstrate substantial (factor of 2) day-to-day variation in cloud drop effective radius at the ARM Southern Great Plains site that is weakly associated with variation in aerosol loading as characterized by light-scattering coefficient at the surface. The substantial scatter suggests the importance of meteorological influences on cloud drop size as well, which should be analyzed in the further intensive studies. Meanwhile, it is notable that the decrease in cloud drop effective radius results in marked increase in cloud albedo.