• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.4
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• pp.85-97
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• 1999

A blind signature scheme is a protocol allowing verifier to obtain a valid signature for a message m from a signer without him seeing the message. This means that the bank in collaboration with the shop cannot trace the electronic cash to user. However anonymous electronic cash also facilitates fraud and criminal acts such as money laundering anonymous blackmailing and illegal purchaes. Therefore in this paper we propose fair blind signature scheme based on KCDSA which is a domestic digital signature scheme and it apply a electronic cash system. In particularly a proposed electronic cash system have an anonymity control ability which trace a user who make use a electronic cash illegally in association with a trusted center.

• Investigative Magnetic Resonance Imaging
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• v.18 no.2
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• pp.120-132
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• 2014

Purpose : To compare dynamic susceptibility contrast imaging, diffusion-weighted imaging, and susceptibility-weighted imaging (SWI) for the differentiation of tumor recurrence and delayed radiation therapy (RT)-related changes in patients treated with RT for primary brain tumors. Materials and Methods: We enrolled 24 patients treated with RT for various primary brain tumors, who showed newly appearing enhancing lesions more than one year after completion of RT on follow-up MRI. The enhancing-lesions were confirmed as recurrences (n=14) or RT-changes (n=10). We calculated the mean values of normalized cerebral blood volume (nCBV), apparent diffusion coefficient (ADC), and proportion of dark signal intensity on SWI (proSWI) for the enhancing-lesions. All the values between the two groups were compared using t-test. A multivariable logistic regression model was used to determine the best predictor of differential diagnosis. The cutoff value of the best predictor obtained from receiver-operating characteristic curve analysis was applied to calculate the sensitivity, specificity, and accuracy for the diagnosis. Results: The mean nCBV value was significantly higher in the recurrence group than in the RT-change group (P=.004), and the mean proSWI was significantly lower in the recurrence group (P<.001). However, no significant difference was observed in the mean ADC values between the two groups. A multivariable logistic regression analysis showed that proSWI was the only independent variable for the differentiation; the sensitivity, specificity, and accuracy were 78.6% (11 of 14), 100% (10 of 10), and 87.5% (21 of 24), respectively. Conclusion: The proSWI was the most promising parameter for the differentiation of newly developed enhancing-lesions more than one year after RT completion in brain tumor patients.

• Journal of the Korean Magnetics Society
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• v.12 no.5
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• pp.184-188
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• 2002

The Cu/Ni/Cu(002)/Si(100) films which have perpendicular magnetic anisotropy were deposited by e-beam evaporation methods. From the reflection high energy electron diffraction pattern, the films were confirmed to be grown epitaxially on silicon. After 2X lots ions/$\textrm{cm}^2$ C+ irradiation, magnetic easy-axis was changed from surface normal to in-plane as shown in the hysteresis loop of magneto-optical Kerr effects. It became manifest from analysis of X-ray reflectivity and grazing incident X-ray diffraction that even though interface between top Cu layer and Ni layer became rougher, the contrast of Cu and Ni's electron density became manifest after ion irradiation. In addition, the strain after deposition of the films was relaxed after ion irradiation. Strain relaxation related with change of magnetic properties and mechanism of intermixed layer's formation was explained by thermo-chemical driving force due to elastic and inelastic collision of ions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1460-1466
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• 2016

This study was conducted to develop a savory ingredient using rice material. We made hydrolysates with ratios of rice bran and rice protein of 4:0, 3:1, 2:2, and 1:3 (w/w) using commercial enzymes, and then investigated their quality properties. At a ratio of 3:1, nitrogen degradation ratio (NDR), savory taste, and overall acceptability were the highest compared to other ratios. Rice bran and rice protein with a ratio of 3:1 were hydrolyzed for 13 days, and characteristics of the hydrolysate were investigated after 3, 5, 7, 10, and 13 days. Total nitrogen, amino nitrogen, and NDR of the hydrolysate after 10 days were higher than those of other hydrolysates. SDS-PAGE showed that the molecular weight of the hydrolysate peptide became smaller as hydrolysis time increased. Glutamic acid content was highest among all amino acids in the hydrolysate for 13 days. Amino acids related to bitter taste decreased from 5 to 13 days, whereas amino acids related to sweet taste substantially increased over time. Sensory evaluation showed that the hydrolysate after 10 days was best. These results suggest that rice bran and rice protein at a mixing ratio of 3:1 and hydrolysis for 10 days were optimal hydrolysis condition for development of natural savory ingredients.

• Journal of Sericultural and Entomological Science
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• v.31 no.1
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• pp.37-44
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• 1989

The parasporal crystals of Bacillus thuringinsis subspecies kurstaki, dendrolimus, finitimus, aizawai and israelensis were compared by polyacrylamide electrophoresis, amino acid composition and immunological analysis. In the subspecies of kurstaki, dendrolimus, finitimus and aizawai, the molecular weights of main subusnits of crystal solubilized by alkaline solution were 1.3${\times}$105 and 6.5${\times}$104 while those of subsp. israelensis were 4${\times}$104 and 1,4${\times}$104. The degradation of lepidopteran toxic subspecies crystals by silkworm midgut protease showed 6.0-6.4${\times}$104 molecular weight and the pattern of degradation of subsp. israelensis crystals was similar to that of alkaline solution treatment. In the amino acid composition, aspartic acid in subsp. israelensis and glutiamic acid in the other four subspecies were the most abundant. The immunological characteristics of the crystals revealed that the antibody produced against the alkali-solubilized crystal protein of subsp. israelensis reacted with only its antigen, but the crystal antigens from the other four lepidopteran toxic subspecies did cross-react with each other as well as with their own homologous antisera.

• Journal of the Korean Magnetics Society
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• v.3 no.2
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• pp.108-114
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• 1993

This paper presents a study on the effects of silica coating in the production of ${\gamma}-Fe_{2}O_{3}$ powders suitable for magnetic recording media. Emphasis has been put on investigating the relationship between the powder characteristics and the effects of silica coating in the heat-treatment stage of ${\gamma}-Fe_{2}O_{3}$ production. After we prepared non-coated ${\gamma}-Fe_{2}O_{3}$ and silica coated ${\gamma}-Fe_{2}O_{3}$ with coating water glass on the surface of goethite and heattreatment process, we compared and investigated powder characteristics. As silica coated layer played a role of preventing the powders from overreduction to metal iron and rapid oxidation, silica coated ${\gamma}-Fe_{2}O_{3}$ showed superior magnetization value due to inhibiting t!1e adulteration of ${\alpha}-Fe_{2}O_{3}$ into the final product. When silica coated layer acted as a sintering restrainer, silica coated ${\gamma}-Fe_{2}O_{3}$ showed high coercivity and specific sur-face area due to good acicularity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.281-286
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• 2010

Effects of soaking period on physicochemical characteristics of chokong (black soybean picked in brown rice vinegar) and soaking solution were investigated. The pH and soluble solid contents in soaking solution increased rapidly whereas total acidity decreased during the first 4 days of soaking. The sudden drop of color 'L' and 'b' values in soaking solution occurred one day after start of soaking; in contrast, 'a' value increased by 1 day, and then decreased for soaking periods. The strength and hardness of chokong showed a decreasing trend as soaking for a long time, and the values of chokong were lower than those of control (black soybean soaked in water and freeze dried). The protein bands of chokong for soaking appeared only under 24,000 Da of molecular weight by electrophoresis. The content of total amino acids of chokong pickled for 7 days was 86.86 mg%, about 3 times for 28.36 mg% of raw black soybean. The contents of essential amino acids, especially, leucine and phenylalanine increased greatly in chokong. In vitro digestibility for protein was 62% in raw black soybean and 84% in chokong pickled for 7 days. Therefore, these results may assumed that chokong will be good source of amino acids.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.27-32
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• 2008

Detailed bathymetry and magnetic survey data for Esmeralda Bank obtained by R/V Onnuri of Korea Ocean Research & Development Institute in September 2007 were analyzed to estimate the locations of possible hydrothermal vents. The shape of Esmeralda Bank is caldera type opened in the western part. The summit is very shallow, about 50 meter b.s.l. and the bottom is about 1300 meter b.s.l. The western part of Esmeralda Bank is more steeper and topographic irregular than eastern part, and showed the valley made by erosion or collapse. The magnetic anomaly patterns of Esmeralda Bank located low anomalies over the north and high anomalies over the south. The magnetic anomalies are steep over the summits and gently smooth over the deep bottom. Two low magnetization zones are located in the summit and westside of Esmeralda Bank. The low magnetization zones of the summits of Esmeralda Bank suggest the possible existence of hydrothermal vent.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.211-216
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• 2001

Top synthetic spin valves wi th structure Ta/NiFe/CoFe/Cu/CoFe(Pl)/Ru/CoFe(P2)/FeMn/Ta on Si (100) substrate with SiO$_2$ of 1500 were prepared by dc magnetron sputtering system. We have changed only the thickness of the free layer and the thickness difference (Pl-P2) in the two ferromagnetic layers separated by Ru, and investigated the effect of magnetic film thickness on the GMR properties and the interlayer coupling field in a spin valve with a synthetic antiferromagnet. As thickness difference of pinned layer was decreased from +25 to -25 , MR ratio was decreased gradually. However, there was a dip zone indicating a big change of MR ratio around Pl = P2, which can be due to the large canting of pinned layers. The modified Neel model was suggested for the top synthetic spin valve to explain the interlayer coupling field according to the thickness change of ferromagnetic layers. The interlayer coupling field was decreased due to the magnetostatic coupling (orange peel coupling) as suggested by model. However, the interlayer coupling field was not explained at the dip zone by the modified Neel model. The deviation of modified Neel model at the dip zone could be due to the largely canting of the pinned layers as well, which depends on different thickness in synthetic antiferromagnetic structure.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.742-748
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• 1998

Experiments have been conducted to investigate synergistic effects and mechanisms of the Alaskan subbituminous coal/polypropylene (PP). Coliquefaction of coal/PP gave the synergistic effect in yields by 17% compared to independent liquefactions of coal or PP at $430^{\circ}C$. To analyse coliquefaction mechanisms, the second and zeroth order kinetic models were developed for coal and PP conversions respectively. When the models were simulated to fit coliquefaction results, those represented results successfully with the correlation coefficient of 0.99. The amount of tetralin needed to liquefy unit mass of coa 1(${\beta}$) was also calculated using the developed model. According to the calculated results, $\beta$ increased from 0.4 to 1.0 as the coliquefaction temperature increased from $410^{\circ}C$ to $470^{\circ}C$. This indicated that tetralin lowered the molecular weight of oil produced, and this phenomenon was recognized by the GPC analyses. Furthermore, it was found that tetralin prohibited the liquefaction of PP when coal was not added. On the other hand, tetralin was believed to act as a hydrogen-donor solvent to coal rather than prohibit PP liquefaction during coliquefaction. Therefore, the liquefaction rate of PP increases and synergistic effects in oil yields are mainly due to the increase in PP liquefaction during coal/PP coliquefaction.