• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.715-720
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• 2014

A Cu(II) complex with an three nitrogens and one sulfur coordination environment was synthesized and characterized. Its redox potential was observed at 0.483 V vs. NHE, very similar to that of a Cu-containing fungal enzyme, galactose oxidase, which catalyzes the oxidation of alcohols to corresponding aldehydes with the concomitant reduction of molecular oxygen to water. The Cu(II) complex selectively oxidizes the benzylic alcohols using TEMPO/$O_2$ under mild reaction conditions to corresponding aldehydes without forming any over-oxidation product. Moreover, the catalyst can be recovered and reused multiple times for further oxidation reactions, thus minimizing the waste generation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.687-690
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• 2005

Recently, to consider financial and constructive aspect, usage of Admixture, like Blast- Furnace Slag and Fly-Ash, are increased. These mineral admixtures, a by-product of steel industry, have many advantage, to reduce the heat of hydration, increase in ultimate strength, improve workability and etc. But it also reduces early-age strength, so it is prevented from using of Blast-Furnace Slag at cold-weather-concrete. In this study, for the purpose of increasing usage of mineral admixtures, like Blast-Furnace Slag and Fly ash, it is investigated the strength properties of concrete subjected to under low temperature According to this study, if early curing is carried out before having frost damage, the strength of concrete, subjected to frost damage, is recovered. And to consider increasing effect of strength, it is more effective to use of mineral admixtures, especially to use blast furance slag.

• 한국산림과학회지
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• 제76권3호
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• pp.295-302
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• 1987

Korea is a small country with extremely high population density. Industrialization of the nation resulted GNP per capita of over 2,000$ in 1986 with an inevitable by-product, high level of pollution in many areas. Forest land is now acknowledged as not only a wood production site but also an origin of much more important intangible values, water and clean air, soil conservation, and recreational and scenic values. Mostly devastated forest land from Korean War has been recovered under the strong afforestation drive from the government. The first Forest Development Plan was mostly reforestation phase and the second Forest Development Plan is foundation establishment phase. The third and later Plans are to enlarge economical forest and to maintain sustatined yield phase. Forestry administration as well as forest research certainly played a great role in successful accomplishment of two Forest Development Plans. For effective planning and accomplishment of the third Forest Development Plan close cooperation among policy makers, forest managers and research workers are mostly required.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.958-961
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• 1999

A new image encoding and identification scheme is proposed for security verification by using CGH(computer generated hologram), random phase mask, and correlation technique. The encrypted image, which is attached to the security product, is made by multiplying QPH(quadratic phase hologram) using SA(simulated annealing) algorithm with a random phase function. The random phase function plays a role of key when the encrypted image is decrypted. The encrypted image could be optically recovered by 2-f system and automatically verified for personal identification. Simulation results show the proposed method cand be used for the reconstruction and the recognition of the encrypted. Image.

• Journal of applied mathematics & informatics
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• 제7권3호
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• pp.941-958
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• 2000

Euler method is generalized to solve the system of nonlinear differential equations. The generalization is carried out by taking a special constant matrix S so that exp(tS) can be exactly computed. Such a matrix S is extracted from the Jacobian matrix of the given problem. Stability of the generalized Euler process is discussed. It is shown that the generalized Euler process is comparable to the fourth order Runge-Kutta method. We also exemplify that the important qualitative and geometric features of the underlying dynamical system can be recovered by the generalized Euler process.

• 한국연초학회지
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• 제27권2호
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• pp.235-243
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• 2005

The government continuously increases cigarette price to reduce the smoking rates. Opinions of cigarette makers and Ministry of Health and Welfare on the effect of cigarette price hike are sharply opposed. This dispute is important because there is possibility of additional increase of cigarette price by 500 won. Therefore, as an inquiry into existing studies for the effect of cigarette price hike on tobacco product, namely analysis of the effect of cigarette price hike consumption, we empirically analyzed the effect of cigarette excise tax hike through establishing improved analytic models considering time trend. As a result, it is substantiated that time trend in the effect of cigarette excise tax hike is certainly exist and early impact is heavy. However, the amount of cigarette consumption is recovered to the level of the average in 5 months. Since it is proved that the long term effect of cigarette price hike is immaterial, health authority should reconsider the plan of additional raising cigarette price by 500 won.

• Journal of the Optical Society of Korea
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• 제4권1호
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• pp.19-22
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• 2000

A new image encoding and identification scheme is proposed for security verification by us-ing a CGH(computer generated hologram), random phase mask, and a correlation technique. The encrypted image, which is attached to the security product, is made by multiplying a QP- CGH(quadratic phase CGI) with a random phase function. The random phase function plays a key role when the encrypted image is decrypted. The encrypted image can be optically recovered by a 2-f imaging system and automatically verified for personal identification by a 4-f correlation system. Simulation results show the proposed method can be used for both the reconstruction of an original image and the recognition of an encrypted image.

• 대한치과의사협회지
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• 제9권12호
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• pp.812-818
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• 1971

The present investigation describes the chemical nature of purified extracellular polysaccharides synthesized by tow resembling streptococci, Streptococcus salivarius strain SD-1 and Streptococcus mitis strain SD-9, which was isolated from human dental plaque, with the following results. 1. Extracellular polysaccharide by Streptoccus salivarius strain SD-1 is recovered mostly in Fraction I-and II-45% of the presne purification procedure, leaving trace amount in Fraction I-and II-70%. 2. The dextran is the major polysaccharides in Fraction I-and II-45% of both strains with minor amounts of levan. 3. The Fraction I-and II-45% of both strains contain glucose and fructose, which its 70% of the same fractions glucose only. 4. It appears that the glycerol was the major end product of the Smith degradation of the Fraction I-45% of both strains.

• 공업화학
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• 제26권3호
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• pp.377-380
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• 2015

본 연구에서는 p-diiodobenzene (PDIB)으로부터 p-phenylenediamine (PPD) 합성 후 생성되는 부산물인 $NH_4I$를 PDIB 합성의 원료로 재활용하기 위하여 $I_2$ 회수 공정의 최적화에 관한 연구를 진행하였다. 양이온교환수지를 사용하여 $NH_4I$ 시약 용액으로부터 $I_2$ 회수에 관한 연구를 진행하였고 양이온교환수지의 파과곡선을 통해 파과점 및 관류교환용량을 조사하였다. 회수되는 요오드의 수율 및 순도 향상을 위해 $NH_4I$의 공급용액 및 산화제($H_2O_2$)의 농도 변화, 상온과 저온 건조공정 그리고 산화시간에 따른 순도와 수율을 측정하여 $NH_4I$ 용액으로부터 요오드를 회수하는 공정의 최적조건을 확립하였다. 또한 산화공정 후 발생하는 여액을 재사용하는 과정을 도입하여 실험한 결과 수율 94.96%, 순도 96.65%의 $I_2$를 회수할 수 있었다.

• Natural Product Sciences
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• 제20권3호
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• pp.216-225
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• 2014

The present study was designed to investigate whether ethylacetate (EtOAc) fraction extracted from Rubus coreanum affect the contractility of the isolated thoracic aortic strips and blood pressure of normotensive rats. The EtOAc fraction ($400{\mu}g/mL$) significantly depressed both phenylephrine (PE, $10{\mu}M$)- and high $K^+$ (56 mM)-induced contractile responses of the isolated thoracic aortic strips in a concentration-dependent fashion. In the simultaneous presence of L-NAME (an inhibitor of NO synthase, $300{\mu}M$) and EtOAc ($400{\mu}g/mL$), both PE- and high $K^+$-induced contractile responses were recovered to the corresponding control level in comparison with inhibition of EtOAc-treatment alone. Moreover, in the simultaneous presence of EtOAc after pretreatment with 0.4% CHAPS, both PE- and high $K^+$-induced contractile responses were recovered to the corresponding control level compared to the inhibitory response of EtOAc-treatment alone. Also, in anesthetized rats, EtOAc fraction (0.3~3.0 mg/kg) injected into a femoral vein dose-dependently produced depressor responses. This hypotensive action of EtOAc fraction was greatly inhibited after treatment with phentolamine (1 mg/kg), chlorisondamine (1 mg/kg), L-NAME (3 mg/kg/30 min) or sodium nitroprusside ($30{\mu}g/kg/30 min$). Intravenous infusion of EtOAc fraction (1.0~10.0 mg/kg/30 min) markedly inhibited norepinehrine-induced pressor responses. Taken together, these results demostrate that EtOAc causes vascular relaxation in the isolated rat thoracic aortic strips as well as hypotensive action in anesthetized rats. These vasorelaxation and hypotension of EtOAc seem to be mediated at least by the increased NO production through the activation of NO synthase of vascular endothelium, and the inhibitory adrenergic modulation.