• Elastomers and Composites
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• v.37 no.2
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• pp.107-114
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• 2002

This paper discusses the accelerated heat aging tests were carried out to predict the useful life of EPDM isolating rubber components of ventilation fan motor for clean room. 20% compression set results changes as the threshold are used for assessment of the useful life and the time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. The useful life at variable temperatures and activation energy are obtained from the Arrhenius relationship. An accelerated test program to assess useful life can be represented an appreciable investment in time was designed. We also considered the effect of antioxidant agents.

• 한국벤처창업학회:학술대회논문집
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• 2023.11a
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• pp.91-96
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• 2023

글로벌로 핵심기술 경쟁 및 최상의 기술을 적용한 제품 제조를 실현해야 하는 ICT 분야의 수출 제조 중소기업은 내부, 외부적인 환경적 요인뿐 아니라 다양한 위기상황을 겪게 된다. 이러한 위기상황을 극복하고자 기업 자체적인 전략을 다방면으로 모색하고 실행하여 성공한 수출 제조 중소 벤처기업인 '(주)쎄믹스'가 있다. 2000년에 설립한 (주)쎄믹스는 반도체 검사장비 중 하나인 Wafer Prober 제조 전문기업으로, 'Simple Perfection'이라는 슬로건 아래 23년간 'OPUS' 및 'OPERA'를 생산, 판매에 전념하고 있는 글로벌 강소기업이며, 지속적인 핵심기술 연구개발을 통해 품질혁신에 성공하였고 글로벌 반도체 검사장비 시장에서 기술적 신뢰와 브랜드 명성을 인정받고 있는 벤처기업이다. 현재 (주)쎄믹스의 입지를 구축하기까지 수출 제조기업으로서 겪은 환율관리 실패인 키코손실에서 기인한 회사 위기를, 자체적으로 기술혁신, 조직혁신, 핵심인재 육성 등 전략적 기업혁신에 성공하여 회사의 존폐위기였던 상황을 극복하였다. 우선 키코손실을 떨쳐내고 새로이 시작하기 위한 S사와의 합병, 분할 후 조직 내부에 기업가정신을 고취하였고 핵심기술을 발굴하여 세계일류상품 인증, 월드클래스 300 선정 및 완수, 6개국에 7개의 자회사 설립 통한 조직혁신, 과감한 인재등용, 인재육성 위한 사내 컨퍼런스 제도 도입, TRIZ 등을 통한 과감한 교육혁신, 인재를 위한 특별한 복지정책 구현 등을 실천하였다. 본 연구는 '(주)쎄믹스'의 위기극복 사례를 통해 일본의 두 곳 대기업만이 누리고 있던 Wafer Prober 장비 시장에서 독자적인 글로벌 판로개척을 통한 자생적 성장시스템 구축과 창의적이고 자기 주도적인 혁신체제를 구축하는 계기를 제공하여 다양한 위기상황에 직면하였거나 위기를 미연에 방지하여야 할 중소기업인과 임직원들에게 성공 사례를 제공하고자 하였다.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.99-103
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• 2015

We conducted reduction reactions of graphene oxide (GO) using three selected reductants. The conductivity and solubility of three kinds of the reduced graphene oxides (RGOs) were examined based on the degree of reduction. When the ethylene glycol (EG) was used as a reductant, the reduction reaction did not sufficiently progress and as a result the conductivity of RGOs was observed to be relatively low. For RGOs made by hydrazine (HZ) and thiourea dioxide (TU), we observed no significant differences in the degree of the reduction, conductivity and dispersity in water. However, RGO prepared by TU showed an exceptionally good solubility in N-methylpyrrolidone, and the solution was stable for more than 4 months.

• Elastomers and Composites
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• v.42 no.3
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• pp.168-176
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• 2007

When the rubber vulcanizates reinforced with carbon black or silica are subjected to cyclic loading from its virgin state, the stress required on reloading is less than that on the initial loading. This stress softening phenomenon is referred to as the Mullins effect. The strain energy function of rubber vulcanizates was investigated using theory of pseudo-elasticity incorporated damage parameter that Ogden and Roxburgh have proposed to describe the damage-induced stress softening effect in rubber-like solids. The quasi-static cyclic loading test was performed using the NR-SBR vulcanizates reinforced with carbon black, and then the effect of a damage parameter to stress-strain curve in reloading and subsequent reloading paths was studied. The strain energy function of the rubber vulcanizates with a different filler content was also evaluated.

• Journal of architectural history
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• v.28 no.5
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• pp.43-58
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• 2019

After the study of Fujishima Gaijiro(1930), although it is common to see that the Tang-ruler(唐尺) was used in the construction of the Silla Sacheonwangsa temple(679), the basis of the discrimination of the construction measure and the detection of the unit length is not actually sufficient since conventional research was done before the excavation. The study was based on archaeological results, which was secured through the excavation research(2006~2012) of the temple site in recent years, to determine the construction measure and try to detect the unit length. In the analysis of the measured value of the ruins, the numerical data were obtained through measurements on drawings of the ruins, the tendency of conversion measure's number appearing by dividing each unit length of the Goguryeo-ruler(高句麗尺) and Tang-ruler within a certain range was compared from the Wansu-je(完數制) viewpoint. The research results are summarized as follows : 1)As a result of the analysis of the distance between the site's center, the case that conversion Cheok's(尺) number is converged to the unit of Jang(丈) within the range of unit length expresses three times more in Tang-ruler, and it is confirmed that a simple multiple relationship based on the unit of Jang is established between conversion Cheok's number. 2)As a result of analysis of Bokan(梁間) of the each Corridor site and the measured value of the stonework ruins, it could be confirmed that appears overwhelmingly in the Tang-ruler when conversion Cheok's number becomes an integer within the range of unit length. The results of the analysis are judged to be a clear basis for viewing the Tang-ruler as the construction measure of the Sacheonwangsa temple. 3)The estimated unit lengths of the construction measure that were obtained from the analysis of the distance between the site'scenter, the foundation stone center distance of the building site and the measured value of the stonework ruins are slightly different. There is a limit to the verification of the construction error about this, however it is difficult to specify, it is mentioned 294.37mm which is obtained from the analysis of the distance between the site's center.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.149-154
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• 2002

Seventy two Duroc $\times$ Yorkshire $\times$ Landrace pigs (75.66$\pm$1.86 kg average initial body weight) were used in a 45 days growth assay to determine the effects of Astragalus membranaceus, ginseng and onion complex on growth performance and carcass characteristics of finishing pigs. Dietary treatments included 1) Control (basal diet), 2) AGO 0.25 (basal diet + 0.25% Astragalus membranaceus, ginseng and onion complex), 3) AGO 0.50 (basal diet+0.50% Astragalus membranaceus. ginseng and onion complex). For overall period, average daily weight gain increased as the concentration of Astragalus membranaceus, ginseng and onion complex in the diets was increased (linear effect, p<0.01). Gain/feed improved without significant difference (p>0.05) as the concentration of Astragalus membranaceus, ginseng and onion complex in the diets was increased. As adding level of Astragalus membranaceus, ginseng and onion complex increased in the diets, A grade appearances of carcass tended to increase (linear effect, p<0.01). The total and LDL+VLDL cholesterol concentrations in serum of pigs fed AGO 0.25 diet were lower than them of pigs fed Control and AGO 0.50 diets without significant difference (p>0.05). $L^{*}$-, $a^{*}$-, and $b^{*}$- value of M. longissimus dorsi muscle were not significantly different among the treatments (p>0.05). Total feed cost per kg of weight gain was lower in the AGO 0.50 treatment (813 won) than in the Control (830 won). The results obtained from this feeding trial suggest that the Astragalus membranaceus, ginseng and onion complex supplementation for finishing pigs had improved growth performance. However, carcass characteristic was not affected by supplemental Astragalus membranaceus, ginseng and onion complex.lex.x.

• Korean Journal of Microbiology
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• v.33 no.3
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• pp.193-198
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• 1997

Microorganisms capable of producing biosurfactant were isolated from oil-contaminated soils and seawater. Among them, the selected strain SW1 was identified as Pseudomonas sp. by taxonomical characteristic tests, and so tentatively named Pseudomonas sp. SWI. The optimal temperature and initial pH for biosurfactant production were TEX>30^{\circ}C.$ and 7.0, respectively. The optimal medium composilion for the production of biosurfactant by Pseudomonas sp. SW1 were hexadecane of 2.0%, yeast extract of 0.04%, $K_{2}HPO_4$ of 0.02%, $KH_2PO_4$ of 0.03% and $MgSO_4$ center dot $7H_2O$ of 0.04%, respectively. Under the above conditions, minimum wrface tension was 32 mN/m after incubation of 2 days. The biosurfactant was produced during initial stationary phase in the optimal medium. Pseudotnonas sp. SWl utilized various hydrocarbons such as Bunker oils, n-alkanes and branched alkanes as a sole carbon source.

• Journal of Pharmaceutical Investigation
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• v.35 no.1
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• pp.45-50
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• 2005

The purpose of the present study was designed to evaluate the bioequivalence of two ofloxacin tablets, Tarivid (Jeil Pharm. Co., Ltd.) and Favid (ILHWA Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four normal male volunteers, $23.67{\pm}3.12$ year in age and $68.50{\pm}7.23$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After four tablets containing 100 mg of ofloxacin were orally administered, blood was taken at predetermined time intervals and concentrations of ofloxacin in plasma were determined using HPLC. Pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$ and untransformed $T_{max}$. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals for the log transformed data were acceptance range of log 0.8 to log 1.25 (e.g., $log0.94{\sim}log1.04\;and\;log0.90{\sim}log1.07\;for\;AUC_t\;and\;C_{max}$, respectively). The major parameters, $AUC_t$, and $C_{max}$, met the criteria of KDFA for bioequivalence indicating that Favid tablet is bioequivalent to Tarivid tablet.

• Analytical Science and Technology
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• v.7 no.3
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• pp.301-313
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• 1994

X-Ray Photoelectron Spectroscopy(XPS) and Rutherford Backscattering Spectroscopy(RBS) are used for the analysis of additives, examination of chemical structure and determination of identity with qualitative and quantitative analysis of surface elements, binding energy level and depth profiling in the surface. We analyzed surface of polyethylene, acrylonitrile butadien rubber, polypropylene, glass, fiber and paper treated with $XeF_2$ or C-F plasma by XPS and RBS. It was found that fluoro element was penetrated to sample surface and the distribution of surface elements are different than untreated samples.

• Korean Journal of Medicinal Crop Science
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• v.13 no.4
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• pp.182-185
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• 2005

Bioassay-guided isolation of the dried roots of Aralia continentalis led to the isolation of (-)-pimara-8(14), 15dien-19-oic acid (continentalic acid) and $(24E)-Stigmasta-5,22-dien-3{\beta}-ol$ (stagmasterol). Their structures were elucidated using $^1H-NMR$, $^{13}C-NMR$, UV and mass spectra analyses. The gram-positive bacterial, including methicilline-resistant (MRSA), were more sensitive to the continentalic acid and stagmasterol than gram-negative bacterial.