• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.2
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• pp.68-71
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• 2006

Active thermography has been used for several years in the field of remote non-destructive testing. It provides thermal images for remote detection and imaging of damages. Also, it is based on propagation and reflection of thermal waves which are launched from the surface into the inspected component by absorption of modulated radiation. For energy deposition, it use external heat sources (e.g., halogen lamp or convective heating) or internal heat generation (e.g., microwaves, eddy current, or elastic wave). Among the external heat sources, the ultrasound is generally used for energy deposition because of defect selective heating up. The heat source generating a thermal wave is provided by the defect itself due to the attenuation of amplitude modulated ultrasound. A defect causes locally enhanced losses and consequently selective heating up. Therefore amplitude modulation of the injected ultrasonic wave turns a defect into a thermal wave transmitter whose signal is detected at the surface by thermal infrared camera. This way ultrasound thermography(UT) allows for selective defect detection which enhances the probability of defect detection in the presence of complicated intact structures. In this paper the applicability of UT for fast defect detection is described. Examples are presented showing the detection of defects in PCB material. Measurements are performed on various kinds of typical defects in PCB materials (both Cu metal and non-metal epoxy). The obtained thermal image reveals area of defect in row of thick epoxy material and PCB.

• Journal of Surface Science and Engineering
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• v.42 no.2
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• pp.95-101
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• 2009

This study is the research on the thermal emissivity depending on the bulk graphite's alignment degree. Bulk graphites were manufactured by uni-axial pressing and subsequent heat treatment of natural graphite flakes with organic binder. The samples were prepared to be $0^{\circ}$ (relative to the 002 c-face), $45^{\circ}$, and $90^{\circ}$ (relative to the 100 a-face) for measuring alignment degree. The alignment degree of the sample was measured by XRD. The thermal emissivity was measured by infrared thermal image camera at $100^{\circ}C$ and compared with the value obtained by Infrared spectroscopy. The alignment degree and thermal emissivity of $0^{\circ}$ sample were measured to be 0 and 0.70 respectively. And those of $90^{\circ}$ sample were 0.73 and 0.80 respectively. The emissivity value was correlated with obtained by IR spectroscopy. Therefore it was considered that the thermal emissivity of the bulk graphite is correlated with the alignment degree.

• Journal of Animal Science and Technology
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• v.66 no.1
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• pp.31-56
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• 2024

Pig farming, a vital industry, necessitates proactive measures for early disease detection and crush symptom monitoring to ensure optimum pig health and safety. This review explores advanced thermal sensing technologies and computer vision-based thermal imaging techniques employed for pig disease and piglet crush symptom monitoring on pig farms. Infrared thermography (IRT) is a non-invasive and efficient technology for measuring pig body temperature, providing advantages such as non-destructive, long-distance, and high-sensitivity measurements. Unlike traditional methods, IRT offers a quick and labor-saving approach to acquiring physiological data impacted by environmental temperature, crucial for understanding pig body physiology and metabolism. IRT aids in early disease detection, respiratory health monitoring, and evaluating vaccination effectiveness. Challenges include body surface emissivity variations affecting measurement accuracy. Thermal imaging and deep learning algorithms are used for pig behavior recognition, with the dorsal plane effective for stress detection. Remote health monitoring through thermal imaging, deep learning, and wearable devices facilitates non-invasive assessment of pig health, minimizing medication use. Integration of advanced sensors, thermal imaging, and deep learning shows potential for disease detection and improvement in pig farming, but challenges and ethical considerations must be addressed for successful implementation. This review summarizes the state-of-the-art technologies used in the pig farming industry, including computer vision algorithms such as object detection, image segmentation, and deep learning techniques. It also discusses the benefits and limitations of IRT technology, providing an overview of the current research field. This study provides valuable insights for researchers and farmers regarding IRT application in pig production, highlighting notable approaches and the latest research findings in this field.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.10
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• pp.63-70
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• 2018

Biomedical signal measurement technology using images has been developed, and researches on respiration signal measurement technology for maintaining life have been continuously carried out. The existing technology measured respiratory signals through a thermal imaging camera that measures heat emitted from a person's body. In addition, research was conducted to measure respiration rate by analyzing human chest movement in real time. However, the image processing using the infrared thermal image may be difficult to detect the respiratory organ due to the external environmental factors (temperature change, noise, etc.), and thus the accuracy of the measurement of the respiration rate is low.In this study, the images were acquired using visible light and infrared thermal camera to enhance the area of the respiratory tract. Then, based on the two images, features of the respiratory tract region are extracted through processes such as face recognition and image matching. The pattern of the respiratory signal is classified through the k-nearest neighbor classifier, which is one of the statistical classification methods. The respiration rate was calculated according to the characteristics of the classified patterns and the possibility of breathing rate measurement was verified by analyzing the measured respiration rate with the actual respiration rate.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.60-66
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• 2016

This study used an ultrasound infrared thermography technique to detect issues in the motor core of typical power equipment. The current defect inspection method of the motor core is often incomplete (due to the limits of visual inspection) and thus the reliability of the motor core is reduced. Therefore, in this study, experiments were carried out to increase the reliability of the test by using an ultrasonic infrared thermal non-destructive inspection method to image the motor core. The ambient temperature of the experimental system was maintained at $25^{\circ}C$. Experiments were carried out to examine a damaged motor core and a defect-free motor core. Experimental results confirm the technique clearly detected defects in the motor core, thereby confirming the possibility of using this technique in the field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.212-215
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• 2003

This paper presents constitution of a moderate price thermography system for on-line measurement. All objects with some temperature above absolute zero radiate in the infrared. The intensities and spectra of the infrared radiated from some object depend on the conditions and temperature distributions on the surface of the objects, and the temperature distributions differ from each others with different undersurface structures. Consequently, infrared radiation is useful for diagnosis of the conditions on the surface and undersurface of electric power apparatus. But the present, because engineers directly measure the temperatures of apparatuses in off-line, the measured data do not always have the information of the past. The proposed system is able to analyze not only the information of the past but the trend of deterioration, and the system is able to compensate for the distortion of surface temperature as to weather conditions. The thermal image histogram is equalized to upgrade observability, and a pan-tilter is adopted to control of direction for any target point.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.277-279
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• 2003

The study utilizes remote sensing as the main monitoring means. With different spatial high-resolution, multichannel ASTER remote sensing image as the main information in Beijing city zone; with regional border and statistical data as auxiliary factor a study between the thermal space distribution character and the underground medium is analyzed based on the GIS logical algorithm and synthetic analysis technology. Results show thermal forming mechanism and the rule of distribution is mainly related to the underground medium and the change of the city distribution. Different underground medium has different degree and intensity influence on the thermal space distribution. Furthermore, urban greenbelt and water areas can reduce the thermal effect and large-scale greenbelt creates green island effect. In addition, Road net, residential area, population density, heat resources and so on have some positive effect on the thermal distribution, which increase the local temperature and intensity on the other hand. It is important to study the thermal distribution and its related factors, which contributes to the plan, construction and development of the city.

• Journal of Astronomy and Space Sciences
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• v.20 no.4
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• pp.393-402
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• 2003

The Multi-Spectral Camera (MSC) is the payload of KOMPSAT-2 which is designed for earth imaging in optical and near-infrared region on a sun-synchronous orbit. The telescope in the MSC is a Ritchey-Chretien type with large aperture. The telescope structure should be well stabilized and the optical alignment should be kept steady so that best images can be achieved. However, the MSC is exposed to adverse thermal environment on the orbit which can give impacts on optical performance. Solar incidence can bring non-uniform temperature rise on the telescope tube which entails unfavorable thermal distortion. Three ways of preventing the solar radiation were proposed, which were installing external mechanical shield, internal shield, and maneuvering the spacecraft. After trade-off study, internal sun shield was selected as a practical and optimal solution to minimize the effect of the solar radiation. In addition, detailed designs of the structure and sunshield were produced and analyses have been performed. The results were assessed to verify their impacts to the image quality. It was confirmed that the internal sunshield complies with the requirements and would improve image quality.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.376-380
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• 2006

Temperature distribution measured to estimate the condition of an electrical apparatus is an absolute reference for the apparatus conditions and the difference between the reference temperature and the current temperature. Because of passive thermography, without the external thermal stimulation, the difference in surface temperature between the region of interest and back ground shows that the results can apply only to the estimation or the monitoring for the condition of loose terminal and the overload pertaining to the rise in temperature. However, a thermal diffusion in the active thermography is differently generated by the structure and condition of the surface and subsurface. This paper presents a nondestructive test using this behavior and deals with the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1250-1254
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• 1992

This paper describes the designed and fabricated thermal imaging system with the SPRITE(Signal PRocessing in The Element) detector, operating in the 3-12 micron band. This system consists of an afocal telescope, a scan unit containing the SPRITE detector, an electronic processor unit and a cooler. The optical scan system utilizing rotating polygon and oscillating mirror, is 2-dimensional serial/parallel scan type using five elements of the detector. And the electronic processor unit performs digital scan conversion to reform the parallel data stream into serial analog data compatable with conventional RS-170 video. The scan field of view is 40 ${\times}$ 26.7 and the MRTD(Minium Resolvable Temperature Difference) is 0.6 K at 7.5 cycles/mm. The acquired thermal image indicates that this system has a satisfactory performance.