• 대한수학회논문집
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• 제35권4호
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• pp.1329-1352
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• 2020

In this paper we consider a class of nonlinear evolution equations on infinite dimensional Banach spaces driven by vector measures. We prove existence and uniqueness of solutions and continuous dependence of solutions on the control measures. Using these results we prove existence of optimal controls for Bolza problems. Based on this result we present necessary conditions of optimality.

• 대한산업공학회지
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• 제4권2호
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• pp.107-118
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• 1978

The paper illustrates a possible application of control theory to an economic growth system. Simultaneous nonlinear system of differential equations has been modeled which is different from the traditional formulation, based on the theory of economic growth for a two-sector (dual) economy. Necessary and sufficient conditions for the existence of the optimal control are derived directly from the Hamiltonian, and the optimal controls are also obtained by solving simultaneous equations. Obtaining the trajectories of the optimal control and state variables, however, should rely on the numerical procedures. Empirical application has been conducted for the case of the Korean economy as an illustration.

• 한국전자거래학회지
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• 제22권2호
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• pp.99-121
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• 2017

모든 영역에서 조직의 디지털 자산을 보호하기 위해, 보안 규제를 강제하고 있는 추세이다. 문제는 조직 내의 보안 통제장치 가운데 투입된 노력이나 보안 수준을 외부에서 확인할 수 없는 통제장치가 존재한다는 것이다. 이 논문에서는 확인할 수 없는 통제장치가 존재하는 경우, 합리적인 보안 수준이 무엇인지 불완전 계약이론을 적용하여 분석하였다. 이를 위해, 확인할 수 없는 통제장치를 무시하는 경우의 비이성적 규제(naive standard)와 모두 확인할 수 있다고 가정할 경우의 완전정보하의 규제와 비교 분석하였다. 결과는 통제장치의 구성에 따라 달라졌다. 우선 평형구성(parallel configuration)하에서는 완전정보하의 규제와 최적규제가 동일하였으며, 순차구성(serial configuration)하에서는 최적규제 수준이 낮아야 하며, 다른 비교대상 규제와는 차이를 보였다. 최적구성(best shot configuration)하에서 확인가능한 통제장치가 비용 효율성이 높은 경우, 흥미롭게도 비합리적 규제가 최적규제수준과 동일한 것으로 나타났다.

• 대한수학회지
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• 제45권3호
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• pp.757-769
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• 2008

This paper deals with the existence of optimal controls and maximal principles for semilinear evolution equations with the nonlinear term satisfying Lipschitz continuity. We also present the necessary conditions of optimality which are described by the adjoint state corresponding to the linear equations without a condition of differentiability for nonlinear term.

• 한국식품조리과학회지
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• 제24권3호
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• pp.358-366
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• 2008

The antioxidant properties of red ginseng extracts prepared under different extraction conditions were evaluated by a variety of antioxidant assays, including $DPPH^{\cdot}$ radical scavenging, $ABTS^{+\cdot}$ radical scavenging, superoxide anion scavenging, nitrite scavenging and reducing power activities. The contents of total phenolic compounds and flavonoids were also determined. The various antioxidant activities were compared to positive controls such as Trolox, tannic acid and ascorbic acid. The antioxidant activities of all of the extracts were shown to be the highest in the ethanol extract. The antioxidant activities of the red ginseng powder were the lowest among the samples. The amounts of total phenolic compounds and flavonoids were at a maximum in the ethanol extract. Correlation analysis demonstrated the existence of a linear relationship between free radical scavenging activities and the phenolic compounds contents of extracts. The antioxidant activity of yogurt was increased as the result of the addition of red ginseng extract. The quality characteristics of the yogurt to which red ginseng extract was added were similar to those of yogurt without red ginseng extract. The overall sensory score and color of yogurt made from 0.5% red ginseng was the best of the tested yogurts. In accordance with the antioxidant activity and quality characteristics, the optimal concentration of red ginseng extract was approximately 0.5%.