• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 한국식품저장유통학회 2003년도 춘계총회 및 제22차 학술발표회
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• pp.136-136
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• 2003

Calcium lactate has been known extending shelf-life of several lactic acid fermented foods through buffer action with lactic acid and binding of calcium and pectic polysaccharides in the tissue. But, the effects in kimchi during storage and distribution has not been observed. Calcium lactate is tasteless, nontoxic compounds commonly used in a number of food products. Recent observations have indicated the potential usefulness of calcium lactate as food additive which has anticariogenic-, antimicrobial-, anticalculus, anti- carcinogenic effects and enhancement of bone mineral density. In this work we determined the effects of calcium lactate(CaL)-treatment(0, 1, 2 and 3% against salted Chinese cabbage) on the pH, acidity, microbial counts, content of alcohol insoluble substance and calcium texture, color, scanning electron microscopic observation of kimchi tissue and sensory test during storage. pH of CaL treated kimchi were higher(3.78∼3.92) than that of control products(3.58). Total microbe(TM) of CaL treated kimchis were lower but ratio of lactic acid bacteria against TM was higher than those of control products, respectively. Calcium content of treated products were 3-5 times higher than control products. The hardness and crispy taste of treated products were remarkably higher than those of control products evaluated by SEM observation AIS analysis, sensory and textural analysis. Moreover, evaluation on the pH, acidity and sensory test showed the shelf-life of treated kimchi(CaL 2%) to be 25-30 days, which was 13-15 days longer than that of control products.

• Journal of the Korean Institute of Intelligent Systems
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• 제14권5호
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• pp.587-592
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• 2004

Context-aware computing systems require real-time context reasoning process for context awareness. Context reasoning can be done by comparing input information from sensors with knowledge-base within system. This method is identical with it of rule-based systems. In this paper, we propose hardware rule-based system architecture which can process context reasoning in real-time. Compared to previous architecture, hardware rule-based system architecture can reduce the number of constraints on rule representations and combinations of condition terms in rules. The modified content addressable memory, crossbar switch network and pre-processing module are used for reducing constraints. Using SystemC for description can provide easy modification of system configuration later.

• Journal of the Korean Society of Food Science and Nutrition
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• 제30권1호
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• pp.152-158
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• 2001

In this study, we determined major foods and food groups which contributed to the intake of folate in korean child-bearing women. Folate content of the major foods was also analyzed. A total of 91 healthy women with childbearing potential participated. They were divided into one of three groups by age; A (15∼24 yrs), B(25∼34 yrs) and C (35∼49 yrs). Food consumption data of the subjects were obtained by the 24-hr recall method. The rate of contribution of each food to the total intake of dietary folate was determined. Seventy major foods for folate were selected from the 178 foods they consumed. Two sets of the 70 foods were collected from different markets. After extracting folates from the foods by heating with a HEPES-CHES buffer, the samples were treated with α-amylase, protease and folate intakes was Korean cabbage kimchi followed by laver, soybean sprout, rice, yolmu kimchi, eggs, lettuce, perilla leaves, sea mustard and radish root. Food items that contributed to folate intake were slightly different among the age groups. Although the folate content of Korean cabbage kimchi was 51.6 ㎍/100g, but due to the high amount of intake, it was ranked the first major food prviding folate. High folate foods containing over 100㎍/100g were laver, corn flakes, spinach, mungbean, sesame, quail's eggs, small radish kimchi, kidney beans, leeks and peanuts. However, based on the serving size, spinach, corn flakes, leeks, sweet potato, pepper leaves, quail's eggs, crown daisy, small radish kimchi and perilla leaves contributed above 50㎍ of folate per serving size.

• Journal of Life Science
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• 제5권2호
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• pp.14-14
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• 1995

The effect of lipoxygenase (LOX) on the oxidation and co-oxidation of lipid fraction was studied in the model system of rainbow trout. For the reaction in model system 1 g of lipid fraction and 50mL of enzyme extract(LOX, 140 unit in 50mL phosphate buffer solution at pH 7,4)), which were obtained from rainbow trout, were homoginized in the presence of Tween 20 and kept at 23$\circ$C for 3 days. The activity of LOX was decreased to 43% of initial level during the reaction in the model system. The initial composition of rainbow trout lipid was showed to be consisted of trigliceride(TG;82%) and free fatty acid(FFA;0.1%), while this converted to 59% of TG and 20% of FIFA, respectively after reaction in model system. Change of fatty acid composition was also observed and the content of linoleic acid, one of the major fatte acids, was decreased to 13% from 54% in the content of total fatty acids after reaction. The carotenoids in rainbow trout were composed of 0.4% $\alpha$-carotene, 1.6% $\beta$ -carotene, 80% canthaxanthin, 7% lutein and 11% zeaxanthin, thus the canthaxanthin was the major component. This canthaxanthin was the most degraded carotenoid by lipoxygenase catalyzed co-oxidation during the reaction. On the other hand the tocopherol isomers found in the rainbow trout were $\alpha$ and $\beta$ -tocopherol, and $\alpha$-tocopherol had a higher degradation rate by the lipoxygenase catalyzed co-oxidation than of $\beta$-tocopherol in the reaction of model system.

• Journal of Pharmaceutical Investigation
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• 제38권1호
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• pp.9-14
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• 2008

Cation exchange resin complex of amlodipine free base has been investigated to improve the stability and dissolution profile. The complex was prepared by reacting amlodipine solution with activated cation exchange resin, and amlodipine content in the complex was 31.6% calculated by HPLC determination. Its product was not physical mixture but the complex formed by ionic bond, which was identified by microscope system, differential scanning calorimetry and X-ray diffractometry. Each tablet containing amlodipine free base(I) and its complex(II) was prepared for the accelerated stability test ($40^{\circ}C$, 75%RH) and dissolution test in the pH 1.2 buffer solution and purified water media. Dissolution patterns of formulation II in both media were similar to those of $Norvasc^{(R)}$ tablet, but the pattern of formulation I in purified water was different. After 6 months storage under stability test, amlodipine content of formulation I, II and $Norvasc^{(R)}$ tablet were $99.3{\pm}1.2%,\;98.9{\pm}1.4%\;and\;83.9{\pm}3.4%$, respectively. While amlodipine free base was unstable at the condition, its complex was not only significantly stable, but also similar in the dissolution pattern. These results suggest the usefulness of complex as a stable carrier for amlodipine free base.

• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.249-254
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• 1997

ABA-type block copolymers composed of poly(L-leucine)(PLL) as the A component and poly(ethylene glycol)(PEG) as the B component were synthesized by ring-opening polymerization of L-leucine N-carboxyanhydride initiated by primary amino group located at both ends of PEG chain. A silver sulfadiazine(AgSD)-impregnated wound dressing of sponge-type was prepared by the lyophilization method. Morphological structure of this wound dressing obtained by scanning electron microscopy(SEM) was composed of a dense skin layer and a macroporous inner sponge layer. Equilibrium water content(EWC) of wound dressing was above 10%. It increased with an increased of PEO content in the block copolymer due to the hydrophilicity of PEO. AgSD release from AgSD- impregnated wound dressing in PBS buffer(pH=7.4) was dependent on PEG composition in the block copolymer. Therefore, EWC and release of AgSD can be control by PEG composition. Antibacterial capacity of AgSD-impregnated wound dressing was examined in agar plate against Pseudmonas aeruginosa and Stapplococus aruous. Cytotoxicity of the wound dressing was evaluated by studing mouse skin fibroblast(L929). From the behavior of antimicrobial releasing and the investigation of the suppression of bacterial proliferation, it was supposed that the wound dressing containing antibiotics could protect the wound surfaces from bacterial invasion to suppress the bacterial proliferation effectively. In cytotoxicity observation, cellular damage was reduced by the control led released of AgSD from the LEL sponge matrix of AgSD-medicated wound dressing. In vivo test, granulous tissue formation and wound contraction or the AgSD and DHEA impregnated wound dressing were aster than any other groups.

• Journal of Ginseng Research
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• 제13권1호
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• pp.92-97
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• 1989

This study investigated the effects of high light intensity (100 KLw) and high temperature (45 ℃, dark) on enzyme (glucose-6-phosphate dehydrogenase, acid phosphatase, catalase, peroxidase, and proteinase) activities and characteristics of Panax ginseng C.A. Meyer leaves. Enzyme activity and protein content decreased rapidly under treatment with high light intensity In P ginseng the thermal stabilities of catalase and peroxidase were high (above 70%), and the coagulation rates of soluble proteins were low (below 17%). Therefore, the decrease in enzyme activity and protein content was not caused by increase in leaf temperature due to the high light intensity, but by increase in proteolytic activities. The photochemical formation rate of superoxide radical (O-2) was higher in the P ginseng leaf extracts than in Solanum nigmm, and was accelerated by addition of crude saponin to the buffer extracts.

• Macromolecular Research
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• 제16권5호
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• pp.429-433
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• 2008

Alginate/carboxymethyl scleroglucan (CMSG) hydrogels were suggested as a novel carrier for the controlled release of protein drugs. The drug release characteristics of alginate hydrogels were improved by CMSG addition. Scleroglucan (Sclg) was carboxymethylated using monochloroacetic acid in aqueous alkaline medium. Alginate/CMSG hydrogels were prepared by dropping the mixture solution of alginate/CMSG into calcium chloride solution. The swelling behaviors and drug release characteristics of the hydrogels were investigated in the buffers of pH 1.2 or 7.4. As the CMSG content increased in the hydrogels, the swelling ratio of the alginate/CMSG hydrogel increased rapidly in the buffer of pH 7.4. At pH 1.2, however, the swelling ratio significantly decreased compared to that at pH 7.4. According to in vitro release tests, only 15% of ovalbumin, investigated as a model protein drug, was released from the alginate/CMSG hydrogels at pH 1.2 within 6 h. At pH 7.4, however, the drug release significantly increased due to the rapid swelling of the hydrogels. The release and swelling behaviors of the hydrogels could be controlled by changing the CMSG content in the hydrogels. These results supported the use of alginate/CMSG hydrogels as a suitable carrier for the controlled release of protein drugs in a pH responsive manner.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제25권8B호
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• pp.1424-1435
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• 2000

A bit-rate controller that can achieve a constant bit rate when coding object-based video sequences is an important part to achieve an adaptation to bit-rate constraints, desired video quality, distribution of bits among objects, relationship between texture and shape coding, and determination of frame skip or not. Therefore we design content-based bit rate controller which will be used for relevant bit-rate control. The implementation is an extension of MPEG-4 rate control algorithm which employs a quadratic rate-quantizer model. The importance of different objects in a video is analyzed and segmented into a number of VOPs which are adaptively bit-allocated using the object-based modelling. Some test sequences are observed by a number of non-experts and interests in each object are analysed. The initial total target bit-rate for all objects is obtained by using the proposed technique. Then the total target bits are jointly analyzed for preventing from overflow or underflow of the buffer fullness. The target bits are distributed to each object in view of its importance, not only of statistical analysis such as motion vector magnitude, size of object shape, and coding distortion of previous frame. The scheme is compared with the rate controller adopted by the MPEG-4 VM8 video coder by representing their statistics and performance.

• Polymer(Korea)
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• 제33권6호
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• pp.581-587
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• 2009

PLA/PEG blend fibers composed of poly (lactic acid) (PLA) and poly (ethylene glycol) (PEG) were prepared via melt blending and spinning for bioabsorbable filament sutures. The blend fibers hydrolyzed with the immersion in a phosphate buffer solution at pH 7.4 and $37\;^{\circ}C$ for 1~8 weeks. The effects of blending time, blend composition, and hydrolysis time on the weight loss and tensile strength of the hydrolyzed blend fibers were investigated. After hydrolysis, the weight loss of the blend fibers increased with increasing PEG content, blending time, and hydrolysis time. The tensile strength and tensile modulus of the blend fibers decreased with increasing PEG content, blending time, and hydrolysis time. Therefore, it can be concluded that the weight loss of the PLA/PEG blend fibers was less than 0.9% even at hydrolysis time of 2 weeks and their strength retentions were over 90%.