• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.188-194
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• 2010

In this paper, the typical Synthetic Aperture Radar (SAR) image quality parameters and analysis method are defined, and the SAR image analysis tool is presented for SAR image evaluation. The structure of the developed SAR image analysis tool consists of four key modules; point target analysis (PTA) module, distributed target analysis (DTA) module, ambiguity analysis (AMA) module, and NESZ analysis (NESZA) module. The developed tool is able to extract the various SAR system parameters from standard SAR product format files. Based on these extracted system parameters, typical SAR image quality parameters are derived from SAR image data.

• BMB Reports
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• v.31 no.5
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• pp.515-518
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• 1998

Adhesive interaction of the platelet glycoprotien IIb-IIIa (GP IIb-IIIa) with a plasma protein, such as fibrinogen, plays an important role in thrombosis and hemostasis. The specific sequence Arg-Gly-Asp (RGD) is critical for the binding of fibrinogen to platelet. To examine and characterize the GP IIb-IIIa antagonist from natural sources, we have developed a simple enzyme-linked immunosorbant assay (ELISA) system. The GP IIb-IIIa complex was purified to homogeneity from platelet Iysates by the combination of two affinity chromatographic methods using the synthetic RGD peptide (GRGDSPK)-immobilized Sepharose and wheat germ lectin-Sepharose. The synthetic peptide GRGDSP inhibits GP IIb-IIIa binding to immobilized fibrinogen with an $IC_{50}$ of $1.5\;{\mu}M$. Venoms of three different snake species and a Korean scolopendra extract have strong antagonistic activities for the binding of human fibrinogen to the platelet GP IIb-IIIa complex. The $IC_{50}$ values of the snake venom s and scolopendra were in the range of $5.5\;{\mu}g$ to $60\;{\mu}g$. These results provide meaningful information for developing antiplatelet agents.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.1-6
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• 2020

In this paper, a method for improving the defect classification performance in steel plate surface has been studied, based on DWT(discrete wavelet transform) and SVM(support vector machine). Surface images of the steel plate have low contrast, uneven, and featureless, so that the contrast between defect and defect-free regions is not discriminated. These characteristics make it difficult to extract the feature of the surface defect image. In order to improve the characteristics of these images, a synthetic images based on discrete wavelet transform are modeled. Using the synthetic images, edge-based features are extracted and also geometrical features are computed. SVM was configured in order to classify defect images using extracted features. As results of the experiment, the support vector machine based classifier showed good classification performance of 94.3%. The proposed classifier is expected to contribute to the key element of inspection process in smart factory.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.167-173
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• 2021

Reactive oxygen species (ROS) disrupt the cellular redox balance, exert cytotoxic effects, and consequently promote the development of various diseases in humans. Previous studies have reported that antioxidants counteract the adverse effects of ROS. Several studies examine the whitening effects of various agents based on their ability to inhibit tyrosinase activity. Tyrosinase is a critical enzyme involved in the synthesis of melanin, which protects the skin against radiation. Various agents exhibiting antioxidant and tyrosinase inhibitory activities have been synthesized. However, these synthetic drugs are associated with toxicity, decreased safety, and poor skin penetration in vivo, which has limited the clinical application of synthetic drugs. This study examined the antioxidant and tyrosinase inhibitory activities of some microalgae. The methanol, dichloromethane, and ethyl acetate extracts of four microalgal species (Tetraselmis tetrathele, Dunaliella tertiolecta, Platymonas sp., and Chaetoceros simplex) were prepared. The physiological and whitening effects of microalgal extracts were investigated by measuring the antioxidant and tyrosinase inhibitory activities. The ethyl acetate extract of D. tertiolecta exhibited the highest antioxidant and tyrosinase inhibitory activities. Future studies must focus on examining the whitening effects of microalgae on cell lines to facilitate the development of microalga-based therapeutics for skin diseases, functional health foods, and whitening agents. Thus, microalgae have potential applications in the pharmaceutical, food, and cosmetic industries.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.3
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• pp.44-51
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• 2001

In general, the realization of spaceborne system is constrained by its space environment. In this paper, we suggest chirp stitching technique which generates and processes wideband radar signal with minimum hardware, design and implement transmit/receive equipments and operating programs to satisfy the requirement of this spaceborne high resolution SAR(Synthetic Aperture Radar). We apply the top down design approach to this system, and divide hardware into equipment, module and circuit levels, and software into SR(Software Requirement), AD(Architecture Design), DD(Detailed Design) and coding levels, and then extract each requirement to satisfy the wideband requirement of this spaceborne high resolution SAR. We, at first, test the hardware functions, confirm the wideband handling capability of this system with 85MHz wideband signals generated from two 42.5MHz narrow band signals, and show that this system can be used in spaceborne high resolution SARs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.303-311
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• 1982

Sensory evaluations of synthetic extracts prepared on the analytical data in the previous papers (Yang and Lee, 1979, 1930-a, 1980-b, 1982) were undertaken to determine the origin of the taste of wild common carp, Cyprinus carpio, and Korean snakehead: Channa argus. Taste panel assessments of synthetic extracts prepared with each extractive component omitted were carried out by a triangle difference test, and changes in taste profile were assessed. The synthetic extracts, prepared with about 40 pure chemicals based on the analytical data from the species satisfactorily revealed the natural taste of the original extracts except slight difference in meaty taste and mildness. From the results of omission test the major components which contribute to produce the taste of the species were assessed as follows: glycine, glutamic acid, arginine, lysine, threonine, alanine, IMP, inosine, hypoxanthine, glucose, succinic acid, $Na^{+},\;Cl^{-}\;and\;PO_{4}^{3-}$ in common carp: glycine, alanine, glutamic acid, IMP, Na+ and $PO_{4}^{3-}$ in Korean snakehead.

• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.207-214
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• 2004

This study was investigated antioxidatve activity for the purpose of developing antioxidant from Morus bombycis Koidzumi. Antioxidant activities of four different organs of Morus bombycis Koidzumi such as fruit, leaf, stem, and root were examined by radical scavenging effect with 1,1-diphenyl-2-picrylhydrazyl (DPPH). 80% methanol extract from the stem showed strongly antioxidative activity and 80% Ethanol extracts from the root, stem, and fruit had high antioxidative activity among 24 samples tested. The 80% ethanol extract has strong absorbency at UVA region (350 nm). The ethyl acetate (EtOAc) fraction exhibited antioxidative activity with $IC_{50}$ of $15.0\;{\mu}g/ml$ similar to those of synthetic antioxidant, BHT The EtOAc fraction has a good absorbency property as synthetic filter. In the absorbance of various extracts, the 80% ethanol and ethyl acetate extracts from the root of Morus bombycis Koidzumi showed higher absorbancy at 285 nm. The ethyl acetate fraction from the root of Morus bombycis Koidzumi contained total phenolic compounds of 654.8 mg/100 g. These results indicate that phenolic compounds are the major was biological components in the root of morus bombycis Koidzumi extracts. Considering these biological activities, the extracts of Morus bombycis Koidzumi showed a possibility to be used as a new material for natural anti-oxidants and substitutes for synthetic UV sunscreen agents.

• Journal of Life Science
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• v.10 no.3
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• pp.241-246
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• 2000

This study was carried out to investigate the antioxidant activity of the water extract from Coptis chinensis Franch. Coptis chinensis Franch. exhibited antioxidative activity at all concentration tested. The extract was as good as antioxidative action of the synthetic antioxidant, butylated hydroxytoluene and ascorbic acid; Also, the one was superior to that of natural antioxidant, $\alpha$ -tocopherol. With heavy metal ions (Fe3+, Zn2+) present, Coptis chinensis Franch. showed strong antioxidative effect.

• Proceedings of the Ginseng society Conference
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• 1987.06a
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• pp.29-37
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• 1987

This study was devised to observe the cytotoxlc activities of petroleum-ether extract of Panax ginseng root(crude Gx) and its partially purified fraction from silicon acid column chromatography(7:3 CX) against sarcoma-180(5-180) and Walker carcinosarcoma 256(Walker 256) in vivo, and murine leukemic lymphocytes(L1210) and human rectal cancer cell(HRT-18) and human colon cancer cells(HT-29 and HCT-48) in vitro . Each cell-line was cultured in medium containing serial concentrations of the crude Gx or 7:3 Gx in vitro. A highly lipid soluble compound in the extract of Panax ginseng root was cytocidal to murine leukemic cells and human colon and rectal cancer cells in vitro In the meantime, ginseng saponin derivatives did not cytotoxic effects at its corresponding concentration. The growth rates of the cancer cells in medium containing ginseng extracts were inhibited gradually to a significant degree roughly in proportion to the increase of the extract concentration. The cytotoxic activity of 7:3 Gx was about 3 times more potent than that of crude Gx, one unit of cytotoxic activity against L121f cells being equivalent to 2.54$\mu\textrm{g}$ and 0.88 $\mu\textrm{g}$ for the crude Gx and 7:3 Gx, respectively. The Rf value of the active compound on silica -gel thin layer chromatography with petroleum-ether/ethyl ether/acetic acid mixture (90:10:1, v/v/v) as a developing solvent was 0.23. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times by the 7:3 Gx treatment compared with their control group. The significantly decreased hemoglobin values of rats after inoculation with Walker 256 were recovered to normal range by oral administration of the crude Gx. The synthetic levels of protein, DNA and RNA in human colon and rectal cancer cells were significantly diminished by treatment with the crude Gx, which can explain a part of the origin of its anticancer activity.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.479-484
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• 2020

In the social atmosphere where the importance of appearance is increasing day by day, efforts and desires of modern people are becoming more active and diversified, and the beauty beauty industry is gradually becoming more specialized and specialized due to these effects. Hair damage is inevitable due to the excessive permanent wave or hair coloring of modern people. However, as the hair is damaged, the cuticle peels off and falls off, and the tensile force decreases and the satisfaction after hair styling or perm decreases relatively. Therefore, it is necessary to manage damaged hair, but since artificial synthetic products occupy most of hair treatment agents on the market, it is necessary to develop a hair treatment product containing antioxidants useful for the human body. In this study, the effect of maple leaf extract on the mechanical change of colored hair was analyzed to investigate the potential of maple leaf extract as a hair treatment agent to improve damaged hair and improve hair health. It is considered that this study will be used as basic data for the development of hair beauty products using natural products in the future.