• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.389-394
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• 2014

This study was conducted to find out the soil $CO_2$ emission characteristic due to rain fall pattern and intensity changes. Using Automatic Opening and Closing Chambers (AOCCs), we have measured annual soil respiration changes in Pinus koraiensis plantation at Seoul National University experimental forest in Mt. Taehwa. In addition, we have monitored heterotrophic respiration at trenching sites ($4{\times}6m$). Based on the one year data of soil respiration and heterotrophic respiration, we observed that 24% of soil respiration was derived from root respiration. During the rainy season (end of July to September), soil respiration at trenching site and trenching with rainfall interception site were measure during portable soil respiration analyzer (GMP343, Vaisala, Helsinki, Finland). Surprisingly, even after days of continuous heavy rain, soil water content did not exceed 20%. Based on this observation, we suggest that the maximum water holding capacity is about 20%, and relatively lower soil water contents during the dry season affect the vital degree of trees and soil microbe. As for soil respiration under different rain intensity, it was increased about 14.4% under 10 mm precipitation. But the high-intensity rain condition, such as more than 10 mm precipitation, caused the decrease of soil respiration up to 25.5%. Taken together, this study suggests that the pattern of soil respiration can be regulated by not only soil temperature but also due to the rain fall intensity.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.623-633
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• 2007

Stable isotope and biomarker analyses were carried out for the organic sediments from the exploratory wells in the Jeju Basin in order to understand the characteristics of organic matter. Organic matter in Geobuk-1, Okdom-1, JDZ VII-1 and VII-2 well is predominantly originated from land plants rather than marine algae according to carbon $({\delta}^{13}C_{org})$ and nitrogen $({\delta}^{15}N_{org})$ isotopic compositions. In the Geobuk-1, geochemical characteristics such as carbon $({\delta}^{13}C_{org})$, nitrogen ($({\delta}^{15}N_{org})$ and TOC contents are obviously changed by the depth 2,400 m, which is likely due to the change of origin of organic matter, sedimentary process or sedimentary environments. Analysis of the saturated fraction of the bitumen suggests the contribution of migrated oil to the indigenous bitumen from the samples 2,509, 2,833 and 3,163 m of the JDZ YII-1 and 3,253 m of the Geobuk-1 well. However, this characteristics can be derived from the contribution of the original organic matter. Based on the biomarker analysis, the samples from the Okdom-1 and Geobuk-1 appear to represent sedimentary organic matter of similar composition, that is rotatively immature, and which was probably deposited in the fluvio-deltaic setting with minor offshore marine influence. The samples from JDZ VII-1 appear to have been deposited in a more terrestrially dominated setting.

• Polymer(Korea)
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• v.36 no.5
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• pp.549-554
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• 2012

It was known that triphenyl phosphate wasn't homogeneously dispersed in HDPE/EPDM/boron carbide blends, which caused the decrease in mechanical properties. HDPE, EPDM, boron carbide, and triphenyl phosphate were blended with PE-g-MAH(polyethylene-graft-maleic anhydride) as a compatiblizer for improving the miscibility of triphenyl phosphate. Tensile strength of HDPE/EPDM/boron carbide blends decreased with increasing the contents of triphenyl phosphate for flammability. However, the mechanical properties of HDPE/EPDM/boron carbide/triphenyl phosphate blends increased by the addition of compatiblizer because triphenyl phosphate was homogeneously mixed in the blend system. The homogeneous dispersibility of triphenyl phosphate was confirmed by using scanning electron microscopy (SEM). Increased thermal stability and flammability derived from high miscibility of triphenyl phosphate were confirmed by the results of thermogravimetric analysis (TGA) and limiting oxygen index (LOI). A self-extinguishing HDPE/EPDM/boron carbide/triphenyl phosphate blend was successfully fabricated with more than 21% LOI.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.2
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• pp.93-102
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• 2017

In this study, various plant extracts were screened for the effective and safe skin care ingredient according to the antioxidant activity assay guidelines. We selected an optimized combination herbal extract, Charmzone extract (CZE), which composed of Nelumbo nucifera leaves, Saururus chinensis and Orostachys japonica. CZE exerted free radical scavenging activity. It reduced reactive oxygen species formation and increased total antioxidant capacities in human keratinocyte (HaCaT) and normal human dermal fibroblasts (NHDF). CZE also leaded procollagen type 1 secretion in NHDF and decreased cellular melanin contents in B16F10. The production of nitric oxide was decreased by CZE in lipopolysaccharide-stimulated RAW264.7 in a dose dependent manner. Therefore, it is concluded that CZE can be applied for naturally derived anti-aging functional skin care ingredient for anti-oxidation, wrinkle enhancement, whitening, anti-inflammation and wound healing of skin.

• Polymer(Korea)
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• v.39 no.2
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• pp.323-328
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• 2015

Poly(${\varepsilon}$-caprolactone) (PCL) nanofibers and PCL/silica membranes were synthesized by sol-gel derived electrospinning and casting, respectively. Smooth PCL nanofibers were obtained from the precursor containing N,N-dimethylformamide (DMF). PCL/silica membranes were prepared by varying the tetraethyl orthosilicate (TEOS) contents from 0 to 40 vol% to investigate the effect of silica addition on mechanical properties and cytotoxicity of the membranes. Although the strength of the membranes decreased from 12 to 8 MPa with increasing the silica content, the strength remained almost constant 7 weeks after dipping in phosphate buffered saline solution (PBS). The strength reduction was attributed to the presence of a patterned surface pores and micro-pores present in the walls between pores. The crystal structure of the membranes was orthorhombic and the crystallite size decreased from 57 to 18 nm with increasing the silica content. From the agar overlay test, the PCL/silica membranes exhibited neither deformation and discoloration nor lysis of L-929 fibroblast cells.

• Journal of Life Science
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• v.19 no.11
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• pp.1553-1561
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• 2009

This study investigated the biological activities and chemical characteristics of Monascus-fermented Korean red ginseng (MFRG). The comparative activities of water, ethanol, and methanol extracts from MFRGE and Korean red ginseng (RG) were tested in vitro of anti-oxidative models of linoleic acid peroxidation by thiocyanate and thiobarbituric acid (TBA) methods and DPPH ($\alpha,\alpha'$-diphenyl-$\beta$-picrylhydrazyl)radical scavenging activities. In addition, measurements of their bioactive total phenolic compounds and minerals, and extract yield, were obtained. The extract yield of each solvent extracted from MFRG and RG was aqueous by 6.58% and 5.83%, ethanol by 0.62% and 0.98%, and methanol by 1.27% and 3.04%, respectively. Total phenolic compounds were higher in all solvents extracted from MFRG than those from RG. Major mineral contents (ppm) of MFRG and RG were K by 16,936 and 22,386, Ca by 2,310 and 3,693, Mg by 2,703 and 2,647, respectively. The DPPH radical scavenging activities were higher in all solvents extracted from MFRG than those from RG, however, all these extracts exhibited a relatively low level of radical-scavenging activity compared to the butylated hydroxytoluene (BHT). In antioxidative activities determined by TBA method using linoleic acid peroxidation, 70% methanol extract from MFRG and RG showed the highest antioxidative activity at a concentration of 0.1%. These results may provide the basic data to understand the biological activities of bio-active materials derived from MFRG.

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.40-44
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• 1995

This study was aimed to mutant induction in Gentiana scabra BUNGE through the tissue culture techniques and comparison of gentiopicroside content in each mutant plants derived from tissue culture. In order to induce the mutants of Gentiam scabra, seed, apical and lateral bud were soaked in $NaN_3$, EMS and MNU solutions and cultured on MS basal medium containing 0.5mg/l NAA, BA $NaN_3$, MNU-treated buds survived about 50% but not survived in EMS treatment. Seed germination rate was extremely low in EMS and MNU treatments but various types of mutant plantlets were obtained by those treatments. 63% of elongated type and 37% of dwarf type were obtained from tissue culture treated by various mutagen. Gentiopicroside contents of regenerated plantlets was analyzed. Root of dwarf type contained more gentiopicroside(1.383%) than that of elongation type (0.083%).

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.39-48
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• 2020

Many studies have been conducted to analyze factors that affect customer satisfaction, and service quality improvement in the parcel delivery industry. Most of these studies have a limited number of respondents using methods such as surveys and interviews. Therefore, this study aims to supplement the shortcomings of previous studies, by searching and analyzing the common major topics related to the complaints pointed out by consumers and suppliers in the parcel delivery service with cases of consumer counseling, and articles that reflect the complaints of workers in the industry. In addition, by analyzing the trend of these topics, we attempted to discover new topics and suggest implications. In conclusion, topics such as delay/lost/wrong deliveries as well as the fierce competition in the parcel delivery industry, turned out to be central aspects. As a result of the topic trend analysis, talks with international couriers have recently increased, and many conflicts related to apartment parcel delivery have been dealt with. The topics presented in this study are mainly focused on the contents of previous studies, but we expect that new and valuable topics can be derived by adding other data and analysis methods, such as internal counseling and academic literature.

• Journal of The Korean Association of Information Education
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• v.16 no.1
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• pp.123-130
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• 2012

As a sequel of "special improvement act for gifted student education" legislated on January 2000, "regulation act for gifted student education" was published on April 2002 which is the time Korea has settled down its education for the gifted. Announced in the December 2007 "general plan for development of gifted student education" provided a platform for the gifted student education in Korea of growth in quantity, in which a plan of providing gifted student education up to 1 percent of the elementary and middle school level students (approximately 70 thousands) has been established while the education currently provides to 0.59 percent (40 thousands) of all students. Until recently, however, education for gifted students has been performed based on the way of concentrating on academic domains. and it has put more weights on mathematics and english domains. In order to overcome this drawbacks, there have been various attempts for growth in quality of education for gifted students, one of them is the our proposal of convergence of science and art education for cultivating 21 century creative humans through establishment of new type of institution. In this paper, education curriculum and management strategies appliable to the proposed convergence education institutions for gifted students. For this purpose we derived the implication points through analysis on education processes used in korea science school for the gifted students, a representative institution for the gifted students in Korea, and we suggested educational process curriculums for the science and art institute for gifted students along with the detailed contents of convergence subject which is an essential subject to the institute.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.3
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• pp.265-286
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• 1997

Bone morphogenetic proteins(BMPs) are a group of transforming growth factor beta(TGF-${\beta}$)-related factors and multifunctional proteins, especially the only known biologic factors capable of inducing endochondral bone formation at an extraskeletal site. This study was performed to investigate the effect of the partially purified porcine BMP(pBMP) at an ectopic site. PBMP was partially purified from porcine bone matrix and its activity was monitored by an in vivo bioassay. The purification method utilized extraction of the bone-inducing activity with 4M guanidine, followed by chromatography on heparin-Sepharose. Active fractions were assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. And the fractions were reconstituted with inactive insoluble collagenous bone matrix from rats, acid soluble type I collagen from rat tail and chondroitin-6-sulfate sodium salt and implanted into the pectroralis muscle pouches of Sprague-Dawley rats. And the carrier complex was implanted on the opposite side as control. The rats were sacrificed at the day of 1st, 3rd, 5th, 7th, 11th, 14th and 21st after implantation and examined histologically, radiologically and biochemically. And alkaline phosphatase activity and calcium content were used as indices of bone formation. The results were as follows ; 1. Active fractions were localized in a zone between 31 and 40 KDa on SDS-PAGE. 2. The implanted 3.0mg of the partially purified pBMP induced cartilage and bone in the muscle tissue of rats through an endochondral ossification process. 3. Inactive insoluble bone matrix, type I collagen and chondroitin-6-sulfate have functioned as carriers for pBMP, but revealed some foreign body reactions. 4. Soft X-ray didn't reveal significant change between the experimental and the control group. 5. The alkaline phosphatase activities in the experimental group of 5th, 7th, 11th, 14th and 21st were increased significantly compared with control (p<0.01) with the peak in the group of 11th day. 6. With time, the calcium content of the experimental group increased. And the calcium contents in the experimental group of 11th, 14th and 21st were increased significantly compared with control (p<0.01).