• 충청수학회지
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• 제22권1호
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• pp.39-47
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• 2009

Pan, Shen and Woo [8] introduced the concept of the G-sequence of a map. We introduce the G'-sequence of a map, which is a dual concept of the G-sequence of a map. We obtain some sufficient conditions for the all sets in the G'-sequence of a map are groups, and for the exact G'-sequence of a map.

• 한국응용과학기술학회지
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• 제34권3호
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• pp.451-460
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• 2017

본 연구는 구기자 항산화 성분의 최적 추출과 항산화 활성의 변화를 모니터링 하였다. 건조 구기자의 추출 조건은 에탄올 농도($X_1$, 0~80%) 및 추출 시간($X_2$, 1~5 hr)이며, 종속변수로는 수율, 안토시아닌, 플라보노이드 및 DPPH 라디컬 소거능으로 반응표면분석을 실시하였다. 가용성 고형분 수율, 안토시아닌, 플라보노이드 및 DPPH 라디컬 소거능에 대한 회귀식의 $R^2$은 각각 0.9066, 0.9859, 0.8645, 0.9464로 1~10%의 유의수준에서 유의성이 인정되었다. 건조 구기자 가용성 고형분 수율이 가장 높은 추출 조건은 에탄올 농도 8.25%에서 4.22 hr 추출한 것(23.12%)으로 나타났다. 안토시아닌이 가장 높은 추출 조건은 에탄올 농도 79.98%에서 3.06 hr 추출한 것(흡광도 1.43)으로 나타났다. 플라보노이드의 가장 높은 추출 조건은 에탄올 농도 67.02%에서 3.37 h 추출한 것($3,100{\mu}g/100g$)으로 나타났다. 그리고 DPPH 라디컬 소거능이 가장 높은 추출 조건은 에탄올 농도 69.81%에서 1.67 h 추출한 것(96.93%)으로 나타났다. 안토시아닌, 플라보노이드 및 DPPH 라디컬 소거능에 대한 등고선도를 겹쳐 그려 얻은 최적 조건(에탄올 농도 70% 및 추출 시간 2,5 hr)으로 추출된 추출물의 안토시아닌은 1.0080(흡광도) 이었으며, 플라보노이드 함량은 $3,145{\mu}g/100g$, 그리고 DPPH 라디컬 소거능은 97%로써 증류수로 1시간 추출한 대조구(안토시아닌 0.4652(흡광도), 플라보노이드 $1,633{\mu}g/100g$ 및 DPPH 라디컬 소거능 87%)에 비해 높은 항산화 성분 추출 및 항산화 효과를 나타내었다.

• 대한화장품학회지
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• 제46권2호
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• pp.185-194
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• 2020

본 연구에서는 진생베리로부터 활성 성분인 ginsenoside Re와 Rb1의 함량과 항산화 활성이 높은 추출물을 얻기 위한 최적의 추출조건을 확인하였다. 70% 에탄올과 증류수를 추출 용매로 하여 교반, 초음파 및 마이크로파를 이용하여 추출한 후 ginsenoside Re와 Rb1 의 함량, 총 폴리페놀 함량, 항산화 활성 및 친환경적 제조 방법 여부를 고려한 결과 증류수 용매의 마이크로파 추출법이 가장 적합한 추출방법인 것을 확인하였다. 마이크로파 추출법의 최적 추출조건을 설정하기 위해 반응표면분석법(RSM)을 사용하여 마이크로파 출력량(50 ~ 200 W, X1), 용매와 진생베리의 비율(5 ~ 20 times, X2), 추출시간(30 ~ 120 s, X3)을 독립변수로 최적화 실험을 진행한 결과 도출된 회귀방정식의 결정계수는 0.9보다 높으며 p-value값은 0.05보다 작아 모델의 적합성이 확인되었다. Ginsenoside와 총 폴리페놀 함량을 위한 최적 추출조건은 마이크로파 출력량(200 W), 진생베리와 추출 용매 비율(20 times), 추출시간(90 s)로 확인되었다. 최적 추출조건에서 총 폴리페놀 함량이 6.23 mg GAE/g, ginsenoside Re 17.69 mg/g, Rb1 16.01 mg/g으로 예측되었고, 실제 실측검증에서 각각 6.33 mg GAE/g, 17.79 mg/g, 15.59 mg/g으로 예측된 값에 대하여 유사한 결과를 확인할 수 있었다.

• Journal of Magnetics
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• 제12권1호
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• pp.27-30
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• 2007

Experimental evidence suggests that spin pinning conditions for standing spin mode in polycrystalline $Ni_{84}Fe_{16}$ alloy film, is confirmed using the four categories of Camley et al. and the value of q$\bot$ for the pinning conditions, this was achieved by performing Brillouin light scattering measurements. The value of q$\bot$ was observed, in order to increase at a rate of $\pi$/2 with an increasing mode number. With this condition, the coexistence of standing spin wave modes was shown, with intermediate pinning, in addition to free and strong pinning. The values for spin-wave-stiffness constant ($D_B$), g-factor (g), and surface magnetization (4$\pi$M) of the Permalloy film were obtained from the results of BLS, and determined to be $D_B=1.85{\pm}0.05Oecm^2$, $g=2.11{\pm}0.02$, and 4$\pi$M=8.7 kG, respectively.

• 농업과학연구
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• 제11권1호
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• pp.53-60
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• 1984

퇴비 온천 논밭토양 등으로부터 항생물질을 생산하는 호열성 곰팡이를 분리하고 그 생산조건을 검토하여 다음과 같은 결론을 얻었다. 1. $45^{\circ}C$에서 생육하는 곰팡이 중 항균력이 강한 H-3균주를 선발하였다. 2. H-3 균주는 형태적 특성에 따라 Aspergillus fumigatus의 근연균으로 동정되었다. 3. 최적배지의 조성은 glucose 20g, $NaNO_3$ 3g, $K_2HPO_4$ 1g, $CaCl_2$ 0.5g, $MgSo_4$ 0.5g, $FeSO_4$ 0.005g이었다. 4. 항생물질 생산을 위한 최적 pH와 온도는 각각 pH5 및 $40^{\circ}C$이었다. 5. 최적 조건하에서 항생물질 생산은 14mm의 저태환으로 72hrs후에 최고에 달하였다. 6. 조정제한 항생물질은 그람양성 및 그람음성 세균과 효모에는 활성이 높았으나 곰팡이에 대해서는 항균력을 볼수 없었다.

• 한국식품영양과학회지
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• 제25권3호
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• pp.513-518
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• 1996

In order to investigate the characteristics of alcohol fermentation by Saccharomyces cerevisiae, compositions and free sugar content of dried riped pumpkin powder were determined. The proximate compositions of ripe pumpkin powder were as follows: moisture 11.98%, total sugar 62.18%(dried weight basis 70.64%), protein 13.38%, lipid 0.85%, fiber 7.07% and ash 4.54%. The compositions of free sugar in well ripe pumpkin were: glucese 85.36mg/g, fructose 40.68mg/g, sucrose 68.25mg/g, lactose 18.60mg/g and maltose 3.82mg/g. The optimum conditions for alcohol fermentation by S. cerevisiae were as follows; incubation temperature of 3$0^{\circ}C$, initial pH of 6.0, ripe pumpkin powder concentration of 10% and cells inoculation of 1.3$\times$$10^{6}$ cells/ml liquid medium. Ethanol production under the optimum conditions was 5.95g/100g in liquid medium containing 10% ripe pumpkin powder after 4 days incubation.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제17권1호
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• pp.39-49
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• 2010

This paper deals with the second-order differential equation (p(t)x'(t))' + g(t)f(t, x(t), x'(t)) = 0, a.e. in (0, $\infty$) with the boundary conditions $$x(0)={\int}^{\infty}_0g(s)x(s)ds,\;{lim}\limits_{t{\rightarrow}{\infty}}p(t)x'(t)=0,$$ where $g\;{\in}\;L^1[0,{\infty})$ with g(t) > 0 on [0, $\infty$) and ${\int}^{\infty}_0g(s)ds\;=\;1$, f is a g-Carath$\acute{e}$odory function. By applying the coincidence degree theory, the existence of at least one solution is obtained.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권3호
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• pp.181-185
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• 2000

A marine microorganism, strain 96CJ10356 produced exopolysaccharide, designated as EPS-R. To optimize culmize culture conditions for the production of EPS-R, carbon and nitrogen sources, mineral salts, temperature, and pH were exmined. From this study, STN medium for the production of EPS-R was suggested as follows; sucrose 20g, typtone 10g, NaCl 10g, MgSO45g, CaCl21g, KH2PO4 76mg, K2HPO4 83mg, FeCl2 5mg, MnCl2 1mg, NaMoO4 1mg, and ZnCl2 1mg per liter at pH 7.0. About 9.23g/L of EPS-R was obtained from STN medium after cultivation for 120h at $25^{\circ}C$ in a 5-liter jar fermentor with an aearation rate of 0.17 vvm. Apparent viscosity and flocculation activity of the culture broth were increased with the production of EPS-R and the maximal values were 415 cP and 1400 unit/mL against 0.5% activated carbon, respectively.

• 한국환경과학회지
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• 제25권11호
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• pp.1541-1554
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• 2016

To understand the characteristics of vanadium leaching from soils formed by the weathering of basalts, paleo soil at Gosan, Jeju Island, Korea, and several present-day soils from neighboring areas were collected. Leaching experiments were carried out by two approaches: 1) batch experiments under various geochemical conditions (redox potential (Eh) and pH) and 2) continuous leaching experiments under conditions similar to those of natural environments. From the batch experiments, leached vanadium concentrations were highest under alkaline (NaOH) conditions, with a maximum value of $2,870{\mu}g/L$, and were meaningful (maximum value, $114{\mu}g/L$) under oxidizing ($H_2O_2$) conditions, whereas concentrations under other conditions (acidic-HCl, $neutral-NaHCO_3$, and $reducing-Na_2S_2O_3$) were negligible. This indicated that the geochemical conditions, in which soil-water reactions occurred to form groundwater with high vanadium concentrations, were under alkaline-oxidizing conditions. From the continuous leaching experiments, the pH and leached vanadium concentrations of the solution were in the ranges of 5.45~5.58 and $6{\sim}9{\mu}g/L$, respectively, under $CO_2$ supersaturation conditions for the first 15 days, whereas values under $O_2$ aeration conditions after the next 15 days increased to 8.48~8.62 and $9.7{\sim}12.2{\mu}g/L$, respectively. Vanadium concentrations from the latter continuous leaching experiments were similar to the average concentration of groundwater in Jeju Island ($11.2{\mu}g/L$). Furthermore leached vanadium concentrations in continuous leaching experiments were highly correlated with pH and Al, Cr, Fe, Mn and Zn concentrations. The results of this study showed that 1) alkaline-oxidizing conditions of water-rock (soil) interactions were essential to form vanadium-rich groundwater and 2) volcanic soils can be a potential source of vanadium in Jeju Island groundwater.

• 충청수학회지
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• 제22권3호
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• pp.497-506
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• 2009

This work studies about the composition polynomial f(g(x)) that preserves certain properties of f(x) and g(x). We shall investigate necessary and sufficient conditions of f(x) and g(x) to be f(g(x)) is separable, solvable by radical or split completely. And we find relationship of Galois groups of f(g(x)), f(x) and of g(x).