• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.89-94
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• 2019

K1A1 tank commander's primary thermal sight is a device that enables tank commanders to detect, identify, aim and track the target by observing targets in all directions during day, night and in situations of smokescreen and fog through $360^{\circ}$ rotation independent from the gunner's primary thermal sight and stabilizing the line of sight even under the vibrations occurring when the tank is standstill and moving. The main function of this device is to detect and process visible and thermal images and deliver the final images to the tank commander. One of the core parts to that end is the observation window (daytime/thermal image window). This core part is mounted at the entrance of the optical path for observing the target and plays the role of making visible light during the daytime and infrared light during the night pass through the target and transmitting the resultant images to the internal optical system of the tank commander's primary thermal sight. Such core parts have been selected as depot maintenance items so that they are replaced by new parts instead of being recycled when they are subjected to maintenance in most cases. That is, the military budget is wasted because such parts are replaced by new parts despite that they can be recycled for maintenance. Therefore, this study proposed a mounting tool for polishing and coating observation windows (daytime and thermal image window) using planar polishing equipment and DLC (Diamond-Like Carbon) coating equipment. In addition, this study presented an amendment (proposal) of the Depot Maintenance Work Request (DMWR) already published to verify the performance of recycled products including the establishment of inspection standards for recycling processes.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1041-1041
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• 2001

Removal of variability in spectra data before the application of chemometric modeling will generally result in simpler (and presumably more robust) models. Particularly for sparsely sampled data, such as typically encountered in diode array instruments, the use of Savitzky-Golay (S-G) derivatives offers an effective method to remove effects of shifting baselines and sloping or curving apparent baselines often observed with scattering samples. The application of these convolution functions is equivalent to fitting a selected polynomial to a number of points in the spectrum, usually 5 to 25 points. The value of the polynomial evaluated at its mid-point, or its derivative, is taken as the (smoothed) spectrum or its derivative at the mid-point of the wavelength window. The process is continued for successive windows along the spectrum. The original paper, published in 1964 [1] presented these convolution functions as integers to be used as multipliers for the spectral values at equal intervals in the window, with a normalization integer to divide the sum of the products, to determine the result for each point. Steinier et al. [2] published corrections to errors in the original presentation [1], and a vector formulation for obtaining the coefficients. The actual selection of the degree of polynomial and number of points in the window determines whether closely situated bands and shoulders are resolved in the derivatives. Furthermore, the actual noise reduction in the derivatives may be estimated from the square root of the sums of the coefficients, divided by the NORM value. A simple technique to evaluate the actual convolution factors employed in the calculation by the software will be presented. It has been found that some software packages do not properly account for the sampling interval of the spectral data (Equation Ⅶ in [1]). While this is not a problem in the construction and implementation of chemometric models, it may be noticed in comparing models at differing spectral resolutions. Also, the effects on parameters of PLS models of choosing various polynomials and numbers of points in the window will be presented.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.130-137
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• 2012

In this paper, a post-analysis of cooling system for infrared(IR) window was performed based on heating experiment of IR window system. We applied the same experimental conditions to analysis, and then validated the analysis technique by comparing numerical and experimental results. For an analysis software, we used a professional heat/fluid analysis program and the numerical and experimental results were in fairly good agreement. We investigated the effect of thermal transfer between the frame and IR window and also a cooling efficiency between fluid and structure in order to determine the proper parameters for the analysis. In this study, 100 % thermal transfer between the frame and IR window and 30 % cooling efficiency between fluid and structure have been proposed, which can be used in the future conceptual design and analysis of similar IR windows.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.572-581
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• 2022

Objective : Compared to microscopes, exoscopes have advantages in field-depth, ergonomics, and educational value. Exoscopes are especially well-poised for adaptation into fluorescence-guided surgery (FGS) due to their excitation source, light path, and image processing capabilities. We evaluated the feasibility of near-infrared FGS using a 3-dimensional (3D), 4 K exoscope with near-infrared fluorescence imaging capability. We then compared it to the most sensitive, commercially-available near-infrared exoscope system (3D and 960 p). In-vitro and intraoperative comparisons were performed. Methods : Serial dilutions of indocyanine-green (1-2000 ㎍/mL) were imaged with the 3D, 4 K Olympus Orbeye (system 1) and the 3D, 960 p VisionSense Iridium (system 2). Near-infrared sensitivity was calculated using signal-to-background ratios (SBRs). In addition, three patients with brain tumors were administered indocyanine-green and imaged with system 1, with two also imaged with system 2 for comparison. Results : Systems 1 and 2 detected near-infrared fluorescence from indocyanine green concentrations of >250 ㎍/L and >31.3 ㎍/L, respectively. Intraoperatively, system 1 visualized strong near-infrared fluorescence from two, strongly gadolinium-enhancing meningiomas (SBR=2.4, 1.7). The high-resolution, bright images were sufficient for the surgeon to appreciate the underlying anatomy in the near-infrared mode. However, system 1 was not able to visualize fluorescence from a weakly-enhancing intraparenchymal metastasis. In contrast, system 2 successfully visualized both the meningioma and the metastasis but lacked high resolution stereopsis. Conclusion : Three-dimensional exoscope systems provide an alternative visualization platform for both standard microsurgery and near-infrared fluorescent guided surgery. However, when tumor fluorescence is weak (i.e., low fluorophore uptake, deep tumors), highly sensitive near-infrared visualization systems may be required.

• Analytical Science and Technology
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• v.5 no.3
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• pp.285-294
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• 1992

Structures of dimers of the acetonitrile and DMF diluted by carbon-tetrachloride and xenon matrices at 80K were studied with infrared absorption spectroscopy. Sample and matrix materials were codeposited onto a KBr cold trapping window. Infrared absorption spectra of pure samples and diluted samples were compared to explain the structures of dimers. The acetonitrile dimer showed the antiparallel shape and the DMF dimer showed the linear shape. After annealing, the infrared spectrum of the diluted sample showed the same shape with that of the pure sample.

• Journal of the Korean Society of Combustion
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• v.10 no.3
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• pp.17-24
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• 2005

A sub-millimeter scale catalytic combustor with a simple plate-shaped combustion chamber was fabricated. A porous ceramics support coated with platinum catalyst was placed in the chamber. The combustor has a gallium arsenide window on the top that is transparent to infrared ray. The temperature distribution in the combustion chamber was measured using infrared thermal imager while hydrogen-air premixture is steadily supplied to the combustor. The area where the catalytic reaction took place broaden for higher flow rate and lower equivalence ratio made activated area in the combustion chamber broaden. The amount of coated platinum catalyst did not affect the reaction. Stop of reaction, which is similar to flame quenching of conventional combustion, was investigated. Large content of heat generation and broad activated area are essential criteria to prevent stop of reaction that has a bad effect on the combustor performance.

• Analytical Science and Technology
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• v.5 no.4
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• pp.455-464
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• 1992

Using FT-IR, we determined the depth of silylated layers produced from various gas-phase-silylation conditions was proposed by using Fourier Transform Infrared (FT-IR) spectroscopic analysis. The depth of silylated layer was determined from absorbance measurments of the significant peaks (Si-O-ph, Si-C, Si-H) of FT-IR spectra with background spectrum subtraction method. And the results were compared with thickness measurments of SEM. The results were well agree with SEM. It found to be well suited for determining silylation process window.

• Atmosphere
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• v.12 no.4
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• pp.69-90
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• 2002

The infrared and microwave satellite observations have been used to derive the information of hydrometeors (i.e., cloud and precipitation) and atmospheric temperature. The observations were made by the Nimbus-4 Infrared Interferometer Spectrometer (IRIS) in 1970, and by the Microwave Sounding Unit (MSU) during the period 1980-99, which had channel 1~4 (Chl~4). The IRIS, which has a field of view of ~100 km, has been utilized to examine the cirrus and marine stratus clouds. The cirrus and stratus distributions were obtained, respectively, based on the spectral difference in the infrared window region, and the absorption of water vapor and $CO_2$ in the spectral region $870-980cm^{-1}$. The MSU Ch1 data has been used for low tropospheric temperature and hydrometeors, while the Ch2, Ch3 and Ch4, respectively, for the thermal state of midtroposphere, tropopause, and lower stratosphere. The climatic aspects of El Ni$\tilde{n}$o, Quasi-Biennial Oscillation (QBO) and temperature trends over the globe are discussed with the MSU data. This study suggests that the IRIS and MSU data are useful for monitoring the hydrometeors and atmospheric thermal state in climate system.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.1
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• pp.45-51
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• 2012

To see sunlight condition around in storage room, this study analyzers the scope both of sunlight and of the shade of sun into upper and lower window according to seasons. For this, this study investigates sun's seasonal changes, its effect of sunlight and notes antinomic conditions for ventilation and draft performance. In this, Architects of Jangkyunggak tride to block discoloration and fading due to ultraviolet rays and visible rays and block deterioration drying of the surface of Kyung-Pan due to infrared rays by oppressing sunlight flowing by means of narrowing the area of the upper window at front face that has a direct influence of Pan-Ga to avoid the exposure to direct sunlight.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.178-178
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• 2010

칼코게나이드계 재료를 사용한 비냉각 적외선 센서의 윈도우를 제작하여 그 특성을 조사하였다. 조성을 EDS로 분석한 결과 Ge-Se-Sb로 구성되어 있음을 확인하였다. 두께 2mm인 윈도우 모재를 양면 경연마한 후 코팅 설계치로 8-12um 영역에서 평균 투과도가 95.6%로 나타났다. 이온빔보조증착장치를 이용하여 Ge, ZnS, $YF_3$ 소스로 코팅한 결과 투과도는 동일파장영역에서 약 94%로 나타났다. 칼코게나이드 원재료의 투과도는 약 69%로써 12um 영역 부근에서 강한흡수를 보였다. 코팅면의 거칠기 값(Ra)은 약 1.5 nm로써 매우 매끄러운 면을 얻었으며, 단면 SEM 측정 결과 설계치와 유사한 박막 두께를 얻었다.