• Journal of applied mathematics & informatics
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• 제8권2호
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• pp.345-360
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• 2001

Affine invariant sufficient conditions are given for two local convergence theorems involving inexact Newton-like methods. The first uses conditions on the first Frechet-derivative whereas the second theorem employs hypotheses on the mth(m≥2 an integer). Radius of convergence as well as rate of convergence results are derived. Results involving superlinear convergence and known to be true for inexact Newton methods are extended here. Moreover, we show that under hypotheses on the mth Frechet-derivative our radius of convergence can sometimes be larger than the corresponding one in [10]. This allows a wider choice for the initial guess. A numerical example is also provided to show that our radius of convergence is larger than the one in [10].

• Journal of applied mathematics & informatics
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• 제6권2호
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• pp.393-406
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• 1999

Affine invariant sufficient conditions are given for two local convergence theorems involving inexact Newton-like methods. The first uses conditions on the first Frechet-derivative whereas the second theorem employs hypotheses on the second. Radius of con-vergence as well as rate of convergence results are derived. Results involving superlinear convergence and known to be true for inexact Newton methods are extended here. Moreover we show that under hypotheses on the second Frechet-derivation our radius of convergence results are derived. Results involving superlinear convergence and known to be true or inexact Newton methods are extended here. Moreover we show that under hypotheses on the second Frechet-derivative our radius of conver-gence is larger than the corresponding one in [10]. This allows a wider choice for the initial guess. A numerical example is also pro-vided to show that our radius of convergence is larger then the one in [10].

• 약학회지
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• 제23권2호
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• pp.63-68
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• 1979

Biopbysical investigation has been carried out for the interaction of riboflavin tetraacetate and an orotic acid derivative to know the binding mechanism between dihydroorotate dehydrogenase and dihydroorotic acid which are concerned with the oxidoreduction in vivo. Infrared and nuclear magnetic resonance spectra were measured for the chloroform solution of riboflavin tetraacetate, orotic acid butyl ester and its same mixture. Orotic acid butyl ester has been found to associate with riboflavin tetraacetate. They form a strong complex with each other. The complex is an 1:2 cyclic hydrogen bonded trimer through the imino and 2-C carbonyl groups of the isoalloxazine ring and the imino groups of the orotic acid derivative.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.45-48
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• 2005

Self compacting concrete has the strong point in capability of concrete to be uniformly filled and compacted in every corners of formwork by its self-weight without vibration during placing. However, powder type self compacting concrete has the weak point in the heat of hydration, the drying shrinkage and the elastic property of concrete etc. Recently viscosity agent has been developed in order to overcome these weaknesses. In this study, self compacting concrete is made with viscosity agent based on polysaccharide derivative in order to develope the normal strength self compacting concrete. Slump flow, loss of slump flow and setting time are measured for comparison with normal concrete. Compressive strength, freezing and thawing test and carbonation test are conducted on normal and self compacting concrete using viscosity agent. In the experiment, we acquired good results in fresh and hardened self compacting concrete using viscosity agent based on polysaccharide derivative.

• Interaction and multiscale mechanics
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• 제2권4호
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• pp.333-352
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• 2009

We introduce a radial basis collocation method to solve axially moving beam problems which involve $2^{nd}$ order differentiation in time and $4^{th}$ order differentiation in space. The discrete equation is constructed based on the strong form of the governing equation. The employment of multiquadrics radial basis function allows approximation of higher order derivatives in the strong form. Unlike the other approximation functions used in the meshfree methods, such as the moving least-squares approximation, $4^{th}$ order derivative of multiquadrics radial basis function is straightforward. We also show that the standard weighted boundary collocation approach for imposition of boundary conditions in static problems yields significant errors in the transient problems. This inaccuracy in dynamic problems can be corrected by a statically condensed semi-discrete equation resulting from an exact imposition of boundary conditions. The effectiveness of this approach is examined in the numerical examples.

• Natural Product Sciences
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• 제20권1호
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• pp.22-28
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• 2014

A new natural product, tetrastigmol A (1), and several known compounds as flavonoids (2 - 8), steroids (9 - 10), bergenin and its derivative (11 - 12), stilbens (13 - 15), lignan (16), benzenecarboxylic derivative (17) and two norisoprenoid (18 - 19) were isolated from the stem of Tetrastigma erubescens Planch. (Vitateae). Their structures were determined on the basis of NMR spectroscopic data. This is the first report on chemical constituents of this plant. Compounds 1, 6 - 8 and 12 - 15 showed strong antioxidant activity using two methods including DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging and lipid peroxidation inhibitory assays.

• 한국자기공명학회논문지
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• 제12권1호
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• pp.33-39
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• 2008

Four sesterterpenoids were isolated from AMPK activity-guided fraction of marine sponge Sarcotragus species. Their planar structures were determined from combination of extensive 1D and 2D NMR experiments and MS data, and the configuration at the chiral centers were assigned by comparison with the $^1H$ and $^{13}C$ chemical shifts of the known compounds. Among four compounds, compound 2 was found to be a new sarcotrine derivative. Though not strong, compounds 1-4 moderately showed AMPK activation effect on L6 myoblast cell through Western Blot analysis.

• Journal of Acupuncture Research
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• 제19권3호
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• pp.126-137
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• 2002

Objective : There is accumulating data that cardiovascular diseases, including hypertension, cerebro-vascular accident, coronary heart disease, relate to atherosclerotic changes. Increased serum levels of lipids could play a role in these circumstances. the SDPTG(the second derivative of photoplethysmogram waveform) is noninvasive methods for evaluating the pulse wave and is correlated with age and other risk factors for atherosclerosis. Methods : To study the effects of serum lipid levels on the SDPTG in the middle-age adults, data on serum lipid levels and the SDPTG were collected in 80 healthy middle age with varying serum lipid concentrations. Biological vascular age was assessed using the SDPTG. the SDPTG consists of an a, b, c, and d wave in systole and an e wave in diastole; an SDPTG aging index(Al) was calculated as (b-c-d-e)/a. Results : Serum triglyceride, total cholesterol, total lipid, phospholipid, HDL cholesterol levels were respectively and significantly correlated with SDPTG Al. Serum lipid levels and blood pressure are age-dependent and the SDPTG is blood pressure-dependent. Restricting analysis to age and blood pressure yield strong positive correlations between serum triglyceride, total lipid levels and SDPTG Al, but no correlations between serum total cholesterol, phospholipid levels and SDPTG Al. Conclusion : The results of this study suggest that preventive acupuncture programs or herbal medications for reducing serum lipid, especially triglyceride, levels in middle-age should include a evaluation of biological vascular aging with the second derivative of photoplethysmogram waveform.

• 원예과학기술지
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• 제28권4호
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• pp.656-663
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• 2010

노란색 유향성 호접란을 육성하기 위해 황화계 육종모본들을 이용하여 5종류의 교배조합이 작성되었으나 $Phal.$ Brother lawrence를 종자친으로 $Phal.$ Brother saragold를 화분친으로 한 교잡에서만 정상적인 교배와 꼬투리 형성 및 종자발아가 이루어졌다. 잡종후대로 약 500개체가 실생 조직배양을 통해 육성되어 온실에 심어졌으며 개화기에 화색과 화형 위주로 60여 우수개체가 1차 선발 되었고 다시 생육속도, 병충해저항성 등을 검정한 2차 선발에서 15계통이 육성되었다. 이들을 대상으로 향기가 비교적 강하고 꽃 수명이 길어 시장에서 기호도가 높을 것으로 예상되는 6계통을 최종 선발하였다. 최종 선발된 이들 유향종들과 이들 교잡종들의 양친을 대상으로 전자코를 이용한 향기패턴분석이 이루어졌다. 전자코로 꽃 향기를 분석한 후 GC chromatogram peak와 이 피크를 이용한 Polar derivative diagram을 작성 비교한 결과 양친에서는 retention time 7s와 9s 사이, retention time 20s와 25s 사이에서 강한 peak가 나타났다. 양친과 비교하여 잡종후대의 선발계통에서는 retention time 7s와 9s 사이 즉 8s 근처에서 하나의 강한 피크가 공통적으로 나타났으며 양친에서 나타났던 retention time 20s와 25s 사이에서 강한 2개의 피크는 교잡후대 중 4개의 계통에서 이 피크가 강하게 발현되었으나 2개의 계통에서는 오히려 거의 나타나지 않았다. 그리고 $VaporPrint^{TM}$ 이미지 분석소프트웨어를 이용하여 향기패턴을 시각적으로 이미지화 한 결과 더욱 명확하게 향기패턴을 비교 분석할 수 있었는데 마찬가지로 교잡양친과 교잡후대계통 모두에서 retention time 8s 근처에서 강한 peak가 공통적으로 나타났으며 이 피크의 성분은 노란색 유향종에서 주로 강하게 발현되는 향기성분인 것으로 판단되었다. 이 피크는 향후 노란색 유향성 개체의 교잡선발 육종에 유용한 마커로서 활용할 수 있을 것으로 판단되었다.

• 생약학회지
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• 제23권4호
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• pp.240-247
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• 1992

Impatiens balsamina Linne(Balsaminaceae) known as 'BONG SUN HWA' in Korea and has been used for the treatment of scrofulosis, carbunculus and dysenteria etc. Bioassay-guided fractionation of MeOH extract from the whole plants of Impatiens balsamina has afforded a simple naphthoquinone derivative, 2-methoxy-1,4-naphthoquinone. The structure of this compound was established by spectroscopic methods. This compound possessed strong antifungal activity against Candida albicans, AspergiIlus niger, Crytococcus neoformans and Epidermophyton floccusum. The activity of 2-methoxy-1,4-naphthoquinone on E. floccusum $(MIC{\;}:{\;}5.0{\;}{\mu}g/ml)$ was the same potency as that of nystatin. It showed also strong antibacterial activity against gram-positive bacteria Bacillus subtilis as well as gram-negative bacteria Salmonella typhimurium. Although the activity of this compound on gram-negative bacteria was lower than that of gram-positive bacteria.