• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.555-563
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• 2018

Thermal infrared images have the characteristic of being able to detect objects that can not be seen with the naked eye and have the advantage of easily obtaining information of inaccessible areas. However, TIR (Thermal InfraRed) images have a relatively low spatial resolution. In this study, the applicability of the pansharpening algorithm used for satellite imagery on images acquired by the UAV (Unmanned Aerial Vehicle) was tested. RGB image have higher spatial resolution than TIR images. In this study, pansharpening algorithm was applied to TIR image to create the images which have similar spatial resolution as RGB images and have temperature information in it. Experimental results show that the pansharpening algorithm using the PC1 band and the average of RGB band shows better results for the quantitative evaluation than the other bands, and it has been confirmed that pansharpening results by ATWT (${\grave{A}}$ Trous Wavelet Transform) exhibit superior spectral resolution and spatial resolution than those by HPF (High-Pass Filter) and SFIM (Smoothing Filter-based Intensity Modulation) pansharpening algorithm.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.5
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• pp.341-348
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• 2015

Active infrared thermography methods have been known to possess good fault detection capabilities for the detection of defects in materials compared to the conventional passive thermal infrared imaging techniques. However, the reliability of the technique has been under scrutiny. This paper proposes the lock-in thermography technique for the detection and estimation of artificial subsurface defect size and depth with uncertainty measurement.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.6
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• pp.609-620
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• 2002

It is well known that during tensile testing, a part of the mechanical work done on the specimen is transformed into heat energy. However, the ultimate temperature rise and the rate of temperature rise is related to the nature of the material, conditions of the test and also to the deformation behaviour of the material during loading. The recent advances in infrared sensors and image/data processing techniques enable observation and quantitative analysis of the heat energy dissipated during such tensile tests. In this study, infrared imaging technique has been used to characterise the tensile deformation in AISI type 316 nuclear grade stainless steel. Apart from identifying the different stages during tensile deformation, the technique provided an accurate full-field temperature image by which the point and time of strain localization could be identified. The technique makes it possible to visualise the region of deformation and failure and also predict the exact region of fracture in advance. The effect of thermal gradients on plastic flow in the case of interrupted straining revealed that the interruption of strain and restraining at a lower strain rate not only delays the growth of the temperature gradient, but the temperature rise per unit strain decreases. The technique is a potential NDE tool that can be used for on-line detection of thermal gradients developed during extrusion and metal forming process which can be used for ensuring uniform distribution of plastic strain.

• Korean Journal of Optics and Photonics
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• v.28 no.4
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• pp.153-157
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• 2017

An infrared camera and laser common-path optical system is applied to DIRCM (directional infrared countermeasures), to increase boresighting accuracy and decrease weight. Thermal effects of a laser beam in a common-path optical system are analyzed and evaluated, to predict any degradation in image quality. A laser beam with high energy density is absorbed by and heats the optical components, and then the surface temperature of the optical components increases. The heated optical components of the common-path optical system decrease system transmittance, which can degrade image quality. For analysis, the assumed simulation condition is that the laser is incident for 10 seconds on the mirror (aluminum, silica glass, silicon) and lens (sapphire, zinc selenide, silicon, germanium) materials, and the surface temperature distribution of each material is calculated. The wavelength of the laser beam is $4{\mu}m$ and its output power is 3 W. According to the results of the calculations, the surface temperature of silica glass for the mirror material and sapphire for the lens material is higher than for other materials; the main reason for the temperature increase is the absorption coefficient and thermal conductivity of the material. Consequently, materials for the optical components with high thermal conductivity and low absorption coefficient can reduce the image-quality degradation due to laser-beam thermal effects in an infrared camera and laser common-path optical system.

• The Journal of Korea Robotics Society
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• v.18 no.1
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• pp.48-52
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• 2023

Many studies have been conducted to ensure that Visual Place Recognition is reliable in various environments, including edge cases. However, existing approaches use visible imaging sensors, RGB cameras, which are greatly influenced by illumination changes, as is widely known. Thus, in this paper, we use an invisible imaging sensor, a long wave length infrared camera (LWIR) instead of RGB, that is shown to be more reliable in low-light and highly noisy conditions. In addition, although the camera sensor used to solve this problem is an LWIR camera, but since the thermal image is converted into RGB image the proposed method is highly compatible with existing algorithms and databases. We demonstrate that the proposed method outperforms the baseline method by about 0.19 for recall performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.4 s.19
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• pp.79-86
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• 2004

This paper has presented to the design results of the analog and digital signal processor for the 2nd generation thermal imaging system using $480\times6$ infrared focal plane array In order to correct non-uniformities of detector arrays, we have developed the 2-point correction method using the thermo electric cooler. Additionally, to enhance the image of low contrast and improve the detection capability, we developed the new technique of histogram processing being suitable for the characteristics of contrast distribution of thermal imagery. Through these image processing techniques, we obtained a high qualify thermal image and acquired good result.

• Journal of the Korean Solar Energy Society
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• v.26 no.4
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• pp.109-118
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• 2006

The tree is regarded as an sustainable architectural outdoor design element which reduce urban heat island effect by its solar shading and evapotranspiration. This study carried out field observations of measuring thermal environment of selected tree and its ambience to determine passive cooling effects. Results from the field observations are as below; Tree-shading effect to the thermal environment can not be properly evaluated by merely measuring air temperature differences between tree-shaded space and unshaded space for the maximum temperature difference is less than $1.5^{\circ}C$. The differences of longwave radiation and shortwave radiation between tree-shaded space and unshaded space are measured. Shortwave radiation is considered as a main thermal comfort determining factor for the difference of the shortwave radiation is much bigger than that of longwave radiation. By thermal infrared image analysis, the surface temperature of the tree under strong solar radiation is measured same as ambient air temperature. By which the evapotranspiration is considered to retard tree surface temperature raising effectively.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.25-32
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• 2010

The paper proposes a hierarchical fault detection method for the high voltage equipment using a microphone array which detects the location of fault and the thermal imaging and CCD cameras which verifies the fault and stores the image, respectively. There are partial arc discharges on the faulty insulators, which generates a specific pattern of sound. Detecting the signal using the microphone array, the location of the faulty insulator can be estimated. The 6th band-pass filter was applied to remove noise signal from wind or external influence. When the mobile robot carries the thermal and CCD cameras to the possible place of the fault insulator, the fault insulators or power transmission wires can be detected by the thermal images, which are caused by the aging or natural erosion. Finally, the CCD camera captures the image of the fault insulator for the record. The detection scheme of fault location using the microphone array and the thermal images have been proved to be effective through the real experiments. As a result of this research, it becomes possible to use a mobile robot with the integrated sensors to detect the fault insulators instead of a human being.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.115-118
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• 2000

Uncooled pyroelectric infrared detectors based on BST(B $a_{-x}$S $r_{x}$Ti $O_3$) thin films have been fabricated by RF magnetron sputtering and surface Micromachining technology. The detectors form BST thin film ferroelectric capacitors grown by RF magnetron sputtering on N/O/N(S $i_3$ $N_4$/ $SiO_2$/S $i_3$ $N_4$) membrane. The sputtered BST thin film exhibits highly c-axis oriented crystal structure that no poling treatment for sensing applications is required. This is an essential factor to increase the yield for realization of an infrared image sensor. surface-Micromachining technology is used to lower the thermal mass of the detector by giving maximum sensor efficiency Gold-black is evaporated on top of the sensing elements used the thermal evaporator. fabricated uncooled pyroelectric infrared detectors is highly output voltage at the low temperature(1$^{\circ}C$).).).

• Journal of Acupuncture Research
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• v.21 no.2
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• pp.223-233
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• 2004

Objective: As a manual accupucture method, the twirling-needle treatment has been known more effective in relieving pain than the conventional simple accupuncture treatment. Finding a proper treatment condition is difficult because of the lack of a quantative measurement of the alleviation of pain made by acupuncture. In this research, the authors propose the use of infrared thermal images in a formalin test to quantatively verify the effect of twirling. Methods: After injecting 10%~20% formalin into the tail of rats, the infrared thermal images(ITI) have been obtained to estimate the thermal distribution caused by inflammation. The authors propose a processing method to measure the thermal distribution from the thermal images obtained from the infrared camera as a pain model of the formalin test. Results: The pain model obtained from the infrared thermal image has two phases. The first phase, which is a transient period, is the initial 20 minutes when the pain is developed after the formalin injection. The second phase, which is a steady state, is where the development of pain lasts for 60 minutes or more after the first stage. This characteristic of the proposed model based on ITI is consistent with that of the pain model reported by other researchers whose works are based on the time-course of flinching and licking/biting, following a different concentration of formalin. It is noticed that the response of the thermal distribution obtained from ITI shows very high correlation to the behavioral response in the formalin test performed by Kazuhiro Okuda and four others5). In addition, the authors propose an ITI method to determine the pain-reducing effect of the acupuncture. The thermal distribution obtained from the experiment shows that there is significant pain reducing effect made by the twirling-needle method.