• Journal of the Society of Naval Architects of Korea
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• v.56 no.5
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• pp.383-388
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• 2019

It is essential to reduce the Infra-red signature for increasing ship's survivability in ship design stage. However the ship's IR signature is quite sensitive to the maritime and atmosphere. Therefore, it is very important to select the marine meteorological data to be applied to the signature analysis. In this study, we selected the three meteorological sample sets from the population of the Korea Meteorological Administration's marine environment data in 2017. These samples were selected through the two-dimensional stratified sampling method, taking into account the geopolitical threats of the Korean peninsula and the effective area of the buoy. These sample sets were applied to three naval ships classified by their tonnage, and then the IR signature analysis was performed to derive the Contrast Radiant Intensity (CRI) values. Based on the CRI values, the validity of each sample set was determined by comparing Cumulative Distribution Function (CDF), and Probability Density Function (PDF). Also, we checked the degree of scattering in each sample set and determined the efficiency of analysis time and cost according to marine meteorological sample sets to confirm the possibility of a probabilistic method. Through this process, we selected the standard for optimization of marine meteorological sample for ship IR signature analysis. Based on this optimization sample, by applying probabilistic method to the management of IR signature for naval ships, the robust design is possible.

• KIISE Transactions on Computing Practices
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• v.23 no.3
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• pp.141-147
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• 2017

Recently there has been an increasing demand for developing a domestic software (S/W) for infrared signature generation to prevent technology leakage and match the domestic operating environment. In this study, we developed a S/W for infrared signature generation and presented its structures and functions for creating and analyzing the IR images of designated spectral bands. The proposed S/W generates IR images of an object through calculations of surface temperatures and IR signals including the self-emitted, surface reflected and path dependent radiances. Moreover, the proposed S/W includes the features of infrared threat analyses from the generated IR images including the infrared contrast radiant intensity (CRI), detection ranges or detection probability analyses, unlike the imported, commercial infrared signature generation S/W.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.3
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• pp.276-283
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• 2012

In this study, it was studies the utilization of LIT(lock-in infrared thermography) which can detect defects in welded parts of ship and offshore structures. Quantitative analysis was used through methods of filtering and texture measurement of image processing techniques to find the optimized experimental condition. We verified reliability in our methods by applying image processing techniques in order to normalize evaluations of comparative images that show phase difference. In addition, low to mid exposure showed good results whereas high exposure did not provide significant results in regards to intensity of light exposure on surface. Lock-in frequency was satisfactory around 0.1 Hz regardless of intensity of light source we had. In addition, having the integration time of thermography camera inversely proportional to intensity of exposed light source during the experiment allowed good outcome of results.

• Macromolecular Research
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• v.11 no.2
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• pp.92-97
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• 2003

Model compounds and polymers having N-substituted 1,2-diphenylmaleimide moieties were synthesized and characterized by NMR, IR, UV, and fluorescence spectroscopy. The fluorescence intensity could be controlled by N-substituents of model compounds and polymers. As the structure of an N-substituent of them was bulkier, or the electron density of an N-substituent was denser, the photoluminescence intensity was increased. All the compounds showed greenish yellow photoluminescence with the maximum intensity between 510 and 537 nm. From quantum efficiency data of the model compounds and the polymers, the fluorescence intensity of the polymer 11 was higher than that of the model compound 4.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.497-499
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• 2002

This paper proposes the effective compensation method fur the IR lamp deterioration in NDIR capnograph system. The newly designed optical chamber with two IR lamps and an electronic hardware for controlling lamp intensity have been implemented. After applying the proposed optical chamber and reference lamp control circuit to the NDIR type capnograph system, it is identified that the proposed method can compensate the lamp deterioration effectively.

• Journal of the Korean Ceramic Society
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• v.22 no.3
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• pp.29-34
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• 1985

The IR spectra of he heavy metal fluoride glasses showed peaks at $1, 400cm^{-1}$ or $1, 100cm^{-1}$ due to metal oxyfluoride impurities. The intensity of this band and hence the oxide impurity content of the glass could be reduced considerably by the use of reactive atmosphere melting under $CCl_4$ In comparison with the fundamental IR absorption band of heavy metal oxides the oxide impurity bands observed in the heavy metal fluoride glasses are multiphonon bands due to a 2-phonon absorption process. The envelope of the a vs. v curve beyond thue fundamental region shows the exponential fall off of a with increasing v-typical of intrinsic multiphonon absorption. In the multiphonon region the amount of structure is intermediate between that observed for covalent solids and that for ionic solids.

• Journal of Sensor Science and Technology
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• v.24 no.4
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• pp.264-269
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• 2015

An infrared (IR) bolometer measures the change of resistance by absorbing incident IR radiation and generates a signal as a function of the radiation intensity. Since a bolometer requires temperature stabilization and light filtering except for the infrared rays, it is essential for the device to be packaged meeting conditions that above mentioned. Minimization of heat loss is needed in order to stabilize temperature of bolometer. Heat loss by conduction or convection requires a medium, so the heat loss will be minimized if the medium is a vacuum. Therefore, vacuum packaging for bolometer is necessary. Another important element in bolometer packaging is germanium (Ge) window, which transmits IR radiation to heat the bolometer. To ensure a complete transmittance of IR light, anti-reflection (AR) coatings are deposited on both sides of the window. Although the transmittance of Ge window is high for IR rays, it is difficult to use frequently in low-price IR bolometer because of its high price. In this paper, we fabricated IR window by utilizing silicon (Si) substrate instead of Ge in order to reduce the cost of bolometer packaging. To enhance the IR transmittance through Si substrate, it is textured using Reactive Ion Etching (RIE). The texturing process of Si substrate is performed along with the change of experimental conditions such as gas ratio, pressure, etching time and RF power.

• Carbon letters
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• v.6 no.2
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• pp.106-110
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• 2005

In this work, the effects of atmospheric oxygen plasma treatment of carbon fibers on mechanical interfacial properties of carbon fibers-reinforced epoxy matrix composites was studied. The surface properties of the carbon fibers were determined by acid/base values, Fourier-transform infrared spectrometer (FT-IR), and X-ray photoelectron spectroscopy (XPS) analyses. Also, the crack resistance properties of the composites were investigated in critical stress intensity factor ($K_{IC}$), and critical strain energy release rate mode II ($G_{IIC}$) measurements. As experimental results, FT-IR of the carbon fibers showed that the carboxyl/ester groups (C=O) at 1632 $cm^{-1}$ and hydroxyl group (O-H) at 3450 $cm^{-1}$ were observed for the plasma treated carbon fibers, and the treated carbon fibers had the higher O-H peak intensity than that of the untreated ones. The XPS results also indicated that the $O_{1S}/C_{1S}$ ratio of the carbon fiber surfaces treated by the oxygen plasma led to development of oxygen-containing functional groups. The mechanical interfacial properties of the composites, including $K_{IC}$ (critical stress intensity factor) and $G_{IIC}$ (critical strain energy release rate mode II), were also improved for the oxygen plasma-treated carbon fibersreinforced composites. These results could be explained that the oxygen plasma treatment played an important role to increase interfacial adhesions between carbon fibers and epoxy matrix resins in our composite system.

• The Korea Journal of Herbology
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• v.30 no.2
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• pp.37-42
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• 2015

Objectives : The aim of this study was to investigate the effects of licorice supplementation on muscle injury, plasma cortisol, testosterone and insulin sensitivity after high intensity resistance exercise. Methods : The fourteen health college male students were voluntarily participated in this study and were randomly divided into 2 groups: Control group (CON, n=7), Licorice group (LR, n=7). LR group ingested 2 g/time of licorice extract (mixed with 100 ml of water) two times/day for 10 days while the CON group ingested 100 ml of water. All subjects performed a high intensity resistance exercise (half-squat, 8 RM at 80% one-repetition maximum, 5 sets, 1min rest). Blood samples were collect before (-7) and after (0) licorice supplementation, and then 1 day, 2 day and 3 day post exercise. After 10 day treatment, plasma creatine kinase, cortisol, testosterone, glucose, insulin were measured. To determine the insulin sensitivity, HOMA-IR was calculated. Results : Plasma creatine kinase activities were significantly elevated after exercise, but there was not different between two groups. The plasma cortisol and testosterone levels were not significantly different between two groups. Plasma glucose levels were increased at 1 day and 2 day after exercise in the LR comparing with CON group (P<0.05) but plasma insulin levels were significantly lower in comparison with CON. HOMA-IR were significantly lower in the LR than CON group at 0 day to 3 day (P<0.05). Conclusions : The results of the current study suggest that licorice supplementation for 10 days might not attenuate the high-intensity exercise-induce muscle injury but may enhance the whole-body insulin sensitivity.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.25-31
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• 2001

The purpose of this study was to investigate the distribution and fluorescence intensity of vasoactive intestinal polypeptide immunoreactive (VIP-IR) cells in rat trigeminal ganglion following pulp extirpation of rat mandibular molar. The animals were divided into control group(n=6) and experimental group(n=6). The experimental animals were sacrificed at 14 days after pulp extirpation. The trigeminal ganglion was removed and immersed in the 4% paraformaldehyde in 0.1M phosphate buffer. Serial frozen sections about $20{\mu}m$ in thickness were cut with a cryostat. The immunofluorescence staining was performed. The rabbit anti-VIP(1 : 8,000) was used as primary antibody and fluorescene isothiocynate(FITC) conjugated anti-rabbit IgG(1 : 80) as secondary antibody. The slides were observed under confocal laser scanning microscope (CLSM). Unprocessed optical sections were obtained and stored on a optical disk. Color pictures were printed by a video copy processor. The results were as follows; 1. The positive ratio of VIP-IR cells in mandibular part of trigeminal ganglion were 7.40% in control group and 28.42% in experimental group(14 days after pulp extirpation). 2. The relative fluorescence intensity of VIP-IR cells in mandibular part of trigeminal ganglion were 87.78 in control group and 138.65 in experimental group. The relative fluorescence intensity of experimental group was 58% higher than that of control group. 3. In optical serial section analysis of VIP-IR cells of experimental group, most of the 9 sections showed high fluorescence intensity. At high magnification, axons of the experimental group displayed greater VIP-IR than in the control group, and the positive cells were mainly of medium size. The result indicate that number and fluorescence intensity of VIP-IR cells were increased in the mandibular part of trigeminal ganglion following pulp extirpation of mandibular molar, and it suggests that VIP could play a role in processing of nociception.