• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.63-63
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• 1999

The stability of hydrogenated amorphous silicon (a-Si:H) films under the light soaking are very important since the applications of a-Si:H films are solar cells, color sensors, photosensors, and thin film transistors(TFTs). We found the changes of the electric conductivity and the conductivity activation energy (Ea) of a-Si:H films by argon radical annealing. The deposition rate of a-Si:H films depends on the argon radical annealing time. The optical band gap and the hydrogen contents in the a-Si:H films are changes along the argon radical annealing time. We will discuss the microscopic processes of argon radical annealing in a-si:H films.

• Journal of Korea Multimedia Society
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• v.10 no.7
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• pp.827-837
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• 2007

Conventional color-based object tracking using Mean Shift algorithm does not provide appropriate result when initial color distribution disappears. In this paper we propose a tracking algorithm that updates the object color sample when the color is changing. Mean Shift analysis is first used to derive the object candidate with maximum increase in density direction from current position. The color information of object is updated iteratively. The proposed algorithm achieves accurate tracking of objects when initial color samples are changed and finally disappeared. The validity of the effective approach is illustrated by the experimental results.

• Journal of Surface Science and Engineering
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• v.53 no.5
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• pp.265-270
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• 2020

We investigated mechanochemical radical, which is concomitant with chemical lift-off lithography(CLL), on the self-assembled monolayer(SAM)/electrodes and a polydimethylsiloxane(PDMS) using a colorimetric and a spectroscopic method. The 11-mercaptoundecanol(MUO)/Au or the 11-hydroxyundecylphosphonic acid (HUPA)/ITO were contacted with bare or activated PDMS. After contact, the each of SAM/substrates and the PDMS were immersed in a 2,2 Diphenyl-1-picrylhydrazyl(DPPH) radical scavenger. The color of the DPPH exposed to the PDMS was changed from purple to yellow and the absorbance decreased definitely at 515 nm wavelength. The SAM/substrates, however, have caused small changes in spectroscopic property, indicating no existence of radical species. We concluded that mechanochemical radicals were formed by homolytic cleavage of PDMS molecules upon external force and hardly transferred on the SAM/substrates.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1229-1234
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• 2017

This study was carried out to investigate the changes in the antioxidant activity of Cheonggukjang with the addition of hazelnut. The number of Bacillus subtilis and the content of crude fat were increased with the addition of hazelnut. The addition of hazelnut made the color of Cheonggukjang lighter. The flavonoid and polyphenol content were sharply increased in proportion to the addition of hazelnut. The DPPH radical scavenging activity of Cheonggukjang was also increased with the addition of hazelnut. Taken together, it was found that the addition of hazelnut had a positive influence on Cheonggukjang by increasing the antioxidant activity.

• KSBB Journal
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• v.27 no.3
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• pp.195-198
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• 2012

This study was carried out to assess the effect of radiation on the changes of Hizikia fusiformis cooking juice ethanol extract and to compare the effect of gamma ray and electron beam. On the applying radiation, the dark color of cooking juice became changed with higher brightness and lower redness and yellowness. But, there was no difference between gamma ray radiation and electron beam radiation. 1,1-Diphenyl-2-picryl-hydrazyl radical scavenging activity and tyrosinase inhibitory activity of cooking juice were shown to be increased by radiation independent on the radiation source types. The reason for the increased biological activities was caused by higher content of total phenolic compounds. The results could be applied to investigate the effect of radiation source on the color and antioxidant activity of biomaterials, and it was thought that irradiation could be an promising method for enhancing the biological activity of biomaterials.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.137-142
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• 2003

This study was carried out to examine the effects of gamma irradiation on the color removal, antioxidation, DPPH radical scavenger, and antimicrobial activity of Schizandra fructus extracts by different solvents. Schizandra fructus was extracted by hot water, ethanol, acetone and methanol, and the extracts were irradiated 10, 20 and 30 kGy with gamma rays. Hunter color L-value was increased by irradiation in a dose-dependent manner, resulting in brighter color for all solvents used. The a and b values were decreased by irradiation in a dose-dependent manner. Antioxidant activity of the ethanol extract of Schizandra fructus against soybean oil was the highest. The free radical scavenging activity was the strongest in hot water extract. All solvent extracts from Schizandra fructus had the strongest antimicrobial activities to B. subtilis, B. natto, B megaterium, S. aureus, Sal. typhymurium and E. coli. These results suggested that Schizandra fructus extracts have a strong potential as natural food preservatives and cosmetic raw materials. Furthermore, irradiation may not influence adversely on biological activites of the extracts when irradiated up to 30 kGy.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.600-606
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• 2010

The objective of this study was to develop functional rice coated with yacon roots extracts and to evaluate the antioxidant properties and physiological activity of rice coated with yacon extract. The washed rice was coated by spraying yacon extract at 10, 20, 30, and $40^{\circ}Brix$ and dried at room temperature. The moisture contents, color changes, antioxidant properties as total polyphenolics and DPPH radical scavenging activity and instrumental texture property and sensory evaluation change in the yacon root extracts coated rice and uncoated cooked rice were observed during 3 days of storage. Increasing the coating concentration was associated with lower color values(L value) and moisture contents. Total phenolics and DPPH radical scavenging properties generally increased in the cooked rice coated with yacon root extract more than the control (non-coated rice). However, D-20($20^{\circ}Brix$ of the yacon root concentration) resulted in better textural properties and sensory overall acceptability in cooked rice on 0 and 3 storage days. It was concluded that the optimum coating ration of rice and added functional yacon rice were $20^{\circ}Brix$ and 7% respectively, in proportion to the total weight of raw rice.

• Food Science and Preservation
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• v.10 no.3
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• pp.388-393
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• 2003

Citrus peel extract was prepared using 70％ ethanol solution by two extraction conditions (20$^{\circ}C$ for 72 hours and 85$^{\circ}C$ for 3 hours). The effect of gamma-irradiation on the changes of physiological activity also investigated at 0, 5, 10 and 20 kGy of absorbed doses. Color characteristics, DPPH radical scavenging, tyrosinase inhibition and nitrite scavenging activities of the extracts were measured at 41$^{\circ}C$ for 30 days. Color values were different by extraction methods at the initial stage, which heat-extracted sample had lower L$\^$＊/ - but higher a$\^$＊/ - and b$\^$＊/ -values than those extracted at room temperature. Irradiation changed color of the extract lighter by increasing Hunter color L$\^$＊/ - and a$\^$＊/ -values. DPPH radical scavenging, tyrosinase inhibition and nitrite scavenging activities were not affected by either extraction methods or irradiation but significantly reduced by storage time. Therefore, when the cost-effective extraction methods is selected, the citrus peel extracts, which is a major byproduct in citrus processing, could be used as a functional material in various applications.

• The Korean Journal of Food And Nutrition
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• v.28 no.6
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• pp.1004-1010
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• 2015

This study was conducted to investigate the changes in the physicochemical characteristics and antioxidant activity of cheonggukjang with the addition of walnuts. The pH of cheonggukjang did not change significantly with the addition of walnut. But the water content decreased significantly. Walnut addition to the soybean was expected to have a positive effect because the number of Bacillus subtilis was not reduced. The viscous substance content was significantly decreased when more than 20% of walnut was added to cheonggukjang. The addition of walnut made the color darker. The flavonoid and polyphenol content was sharply increased in proportion to the walnut addition and the DPPH radical scavenging activity of cheonggukjang also increased. Altogether, it was found that the addition of walnut had a positive influence on the cheonggukjang by increasing the antioxidant activity.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.342-354
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• 2018

Suaeda japonica is a halophytic plant that lives in mudflat at intertidal zone of western and southern coastal areas of Korea. The seawater-living plants showed a purple color during their whole life. In contrast, freshwater-living plants displayed a green color in leaves. When seawater-living plants were transferred to potting soil, the purple color was gradually changed to green in the leaves. The extracted purple pigment compound exhibited typical characteristics of betacyanin that were represented by water solubility, pH- and temperature-dependent color changes, sensitivity to light, UV-Vis spectra, and gel electrophoretic migration pattern. The LC-MS analysis of the extracted pigment compound showed the presence of two major protonated molecular ions ($[M+H]^+$) at m/z 651.1 and m/z 827.1. Antioxidant activity of the pigment compound was determined using stable free radical DPPH assay. It was found to have an antioxidant activity that is linearly increased in proportion to the reaction time for up to 30 min, and the activity was comparable to that of control BHA at 9.0 mg/ml. The anticancer activity against several tumor cell lines was also examined following the MTT assay. The significant growth inhibitory effect was observed on two tumor cell lines, SW-156 (human kidney carcinoma) and HEC-1B (human endometrial adenocarcinoma). Probably, the pigment compound may function as an osmolyte to uphold halotolerant physiological processes in saline environment.