• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.101-108
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• 2003

Polymeric positive temperature coefficient(PTC) composites have been prepared by incorporating carbon black(CB) into high density polyethylene(HDPE), polyphenylene sulfide(PPS) and polybutylene terephthalate(PBT) matrices. A PTC effect was observed in the composite, caused by the large thermal expansion due to He consecutive melting of HDPE, PPS and PBT crystallites. This theory is based upon the premise that the PTC phenomenon is due to a critical separation distance between carbon particles in the polymer matrix at the higher temperature. The influence of PTC characteristics of the PPS/CB composite can be explained by DSC result. HDPE, one of prepared composition, exhibit the higher performance PTC behavior that decreaseing of negative temperature coefficient(NTC) effect and improved reproducibility by chemically crosslinking. Also, PBT/CB and PPS/CB composites exhibit the higher PTC peack temperature than HDPE/CB PTC composite, individually $200^{\circ}C$ and $230^{\circ}C$. These PTC composite put to good use in a number of safety application, such as self$.$controlled heater, over-current protectors, auto resettable switch, high temperature proctection sensor, etc.

• Journal of the Korean Society of Costume
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• v.54 no.2
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• pp.66-78
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• 2004

A leather clothes which was a representative item of an existed resistant image created a new esthetics. Cyber Resistance, being mixed with the highlighted cyber image in these days. Especially. the image of such new leather clothes appears apparently in SF movies. The purpose of this study is to examine this new esthetics through the leather clothes of the movie. $\ulcorner$Matrix$\urcorner$. currently becoming the subject of a conversation and affecting to a popular culture and the fashion and to help to the design idea of a unique leather clothes. The result of analyzing of the character in the movie is following. Trinity shows herself as a woman warrior by wearing tight black leather suit. Morpheus is described as a vague character with his old fashioned suit and leather trench coat. while Niobe carries an image of rebellious cyber warrior in her leather suit with unique texture. In addition. leather clothes on $\ulcorner$Matrix$\urcorner$ got the name of Matrix look and became a main theme in fashion collection. We can feel 'Cyber Resistance' esthetics in that leather clothes through the movie and fashion collection and summarize into three following features, First. it's grafted into the dichotomous value by progress and return as a retro futurism. Second. it moderately express a rebellious image of punk into a cyber image. Third. it makes cyber warrior's image that is neutralized mixing military and fetish properly.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.67-70
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• 2002

The RAPD data were used to assess genetic similarity among f grape cultivars. Of the 100 random primers tested on genomic DNA, 10 primers could be selected for Benetic analysis, and the selected primers generated a total of 115 distinct amplification fragments. A similarity matrix was constructed on the basis of the presence or absence of bands. The 7 grape cultivars analyzed with UPGMA were clustered into two groups of A and B. The similarity coefficient value of cultivars was high. The mean similarity index for all pairwise comparisons was 0.851, and ranged from 0.714 ('Rosaki' and 'Black Olympia') to 0.988 ('Kyoho' and 'Daebong'). After due consideration of differences in cultural and morphological characteristics of these two theoretically identical cultivars, it could be deduced that 'Daebong' is a bud sport of 'Kyoho' cultivar.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.21-27
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• 1991

This paper outlines the method of formulating the bi-cubic B-spline surface of ship hull, employing the open uniform knot vector as well as the periodic uniform knot vector. An appropriate set of B-spline control vertices to generate the B-spline surface is determined by obtaining the pseudoinverse matrix of basis functions. The comparison between the given offsets and the resulting coordinates from the generated ship hull surface shows a good agreement. To check the fairness of the surface Gaussian curvature is calculated on many small subpatches and displayed on the black-and-white plot of the isoparametric net of the surface.

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.648-652
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• 1998

TIG remelting was performed to harden the surface of automobile earn shaft. Multipass remelting was conducted in longitudinal direction under argon gas atmosphere. The microstructure of as-east earn shaft was gray iron which consisted of flake graphite and pearlitic matrix. The remelted area had microstructue of both fine pearlite and ledeburite structure that consisted of globular austenite and $Fe_3C$. Hardness for as-cast earn shaft had HRc 25~28, however it increased at remelted area to HRc 53~55. Black line was found at heat affected zone next to the fusion line, that is remelt area of previous pass, during multipass remelting. Black line was identified as graphite, which was transformed from $Fe_3C$. in the ledeburite structure. It is observed that all graphites were nucleated at $Fe_3C$. and matrix interface. High density energy laser remelting process was also applied to verify whether black line could be eliminated. However, black line was still existed as observed in TIG remelting process. Regraphitization was simulated on the ledeburitic structure specimen using Gleeble 1500 with conditions of 1100 and 100$0^{\circ}C$ for 0.5, I, 3, 5 and 1Osee. From the fact that graphite was formed even at the simulation condition of 100$0^{\circ}C$ for 0.5sec, it is seen that regraphitization is an inevitable phenomenon generated whatever processes used during multipass overlap remelting.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.241-246
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• 2004

To develop novel anti-aging peptides from the germinated black rice, we treated with bromelain, papain and Pronase E. And we investigated the effects of the germinated black rice peptide (GBRP) as anti-aging cosmetic ingredients, and compared with the non-germinated black rice protein (NBRP). We investigated the effects on in vitro inhibition of matrix-metalloprotease (MMP), proliferation of human skin fibroblasts, stimulation of collagen synthesis and expression of UVA-induced MMPs in human skin fibroblasts, UVA induced MMP-1 expression and collagen contents in human skin fibroblasts were analyzed by enzyme-linked immunosorbent assay (ELISA). As a result, the molecular weight distributions of GBRP and NBRP were determined by gel permeation chromatography to be approximately 900 and 10,000 daltons. GBRP increased skin cell proliferation about 40% and reduced UVA-induced MMP-1 expression about 50%. Also the collagen protein level of cells, which were cultured with GBRP, was increased about 25%. These results suggest that the geminated plant seed peptides can be novel anti-aging ingredients for cosmetics.

• Journal of Life Science
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• v.20 no.5
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• pp.736-744
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• 2010

The root of Playtcodon grandiflorum, called Platycodi radix, has been a favorite edible plant in Asia and contains a large amount of saponins. Melanoma cells (B16F10) were used to investigate the inhibitory effect of aged black Platycodi radix extract (ABPRE) on oxidative stress and matrix metalloproteinases (MMPs). Platycodon radix has been known to have a variety of medicinal effects such as prevention of gastric ulcers, antiallergenic activities, histamine release inhibition, and antioxidant effects. However, the mechanism of its action remains unclear in humans. ABPRE was prepared using ethanol extraction of aged black Platycodi radix. In an antioxidant effect study of ABPRE, it was observed that ABPRE specifically exhibited the scavenging activity of DPPH radical, but did not inhibit the production of malondialdehyde from lipid peroxidation. DNA oxidation was also blocked in the presence of ABPRE. In addition, ABPRE decreased the expression and activation of MMP-2 stimulated by phenazine methosulfate. Furthermore, ABPRE revealed the inhibitory effect on melanin production induced by L-dopa via antioxidant effect and the reduction of tyrosinase expression. Especially, the expression of antioxidant enzymes such as SOD-1 and SOD-2 regulated by Nrf2 was increased in the presence of ABPRE. Therefore, it appears that ABPRE may be a possible chemopreventive agent for the prevention of metastasis related to oxidative stress.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.351-354
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• 2003

최근 안전 분야에서 기능성 고분자 재료의 응용분야로서 첨단 전기전도성 고분자복합재료를 이용한 섬유상, 구형, flake 등 각종 형상의 금속, 흑연, carbon black, whisker 등의 전도성 filler를 고분자 matrix에 혼입하여 전도성 고분자를 성형가공하여 복합성형체를 제조하고 electrical hazard를 감소시키기 위한 정전기방지효과, 자기발열체, 전자기파 차폐효과 등의 특성을 나타내는 고분자 성형체상으로 가공된 소재로 화학공장, 산업설비, 각종 제조설비의 제조 공정용 제어, 과전류차단 및 외부 전자기파에 의해 발생되는 이상작동 등을 방지하는 안전시스템 소재용으로서 다양하게 사용되고 있다.(중략)

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.192-195
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• 2003

최근 첨단기술 집약형 자동화 시스템과 정보기술의 발달에 따라 산업은 고도화, 정밀화되고 있다. 특히 안전분야 중 기능성 고분자 재료의 응용 분야로서 carbon black, carbon fiber, graphite, 금속 분말 등의 전도성 충전재를 고분자 matrix에 혼입하여 전도성 복합재료를 성형가공하는 기술이 개발되고 있다. 이를 이용한 복합성형체는 과전류 차단, 회로 보호, 전자파 차폐효과 등의 특성을 이용한 electrical hazard 감소 효과, 제어설비, 자동화 설비, 제조설비 등 각종 산업설비의 정밀제어, 과전류차단 및 외란 방지 등에 다양한 용도로 활용되고 있다.(중략)

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.917-919
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• 2003

The effect of conducting carbon layer on the performance of AC thin film EL display was examined. It was found that incorporation of small amount of carbon nano-tube and conducting additive greatly improve the luminance of the inorganic EL compared to the one with only conducting carbon black.