• 한국수학교육학회지시리즈B:순수및응용수학
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• 제4권1호
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• pp.27-33
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• 1997

Let (M = B$\times$f F, g) be an ($n \geq3$ )-dimensional differential manifold with Riemannian metric g. We solve the following elliptic nonlinear partial differential equation (equation omitted). where $\Delta_{g}$ is the Laplacian in the $\Delta$g-metric and ($h(\chi)$) is the scalar curvature of g and ($H(\chi)$) is a function on M.

• BMB Reports
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• 제33권4호
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• pp.289-293
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• 2000

Annexin I is a 37 kDa member of the annexin family of calcium-dependent phospholipid binding proteins. Annexin I plays regulatory roles in various cellular processes including cell proliferation and differentiation. Recently we found that annexin I is a heat shock protein (HSP) and displays a chaperone-like function. In this paper we investigated the function of annexin I as an ATPase using 1 to 32 amino acids deleted annexin I (${\Delta}-annexin$ I). ${\Delta}-Annexin$ I hydrolyzed ATP as determined by thin layer chromatography. The ability of ATP hydrolysis was inhibited by ADP, GTP and GDP, but not by the AMP, GMP and cAMP. In view of the ATP hydrolyzing function of HSP, the results support the function of annexin I as a HSP.

• Journal of the Korean Data and Information Science Society
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• 제16권4호
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• pp.815-821
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• 2005

Among the various artificial neural networks the backpropagation network (BPN) has become a standard one. One of the components in a neural network is an activating function or a transfer function of which a representative function is a sigmoid. We have discovered that by updating the slope parameter of a sigmoid function simultaneous with the weights could improve performance of a BPN.

• IMMUNE NETWORK
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• 제15권4호
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• pp.206-211
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• 2015

Pulmonary edema is a major cause of mortality due to acute lung injury (ALI). The involvement of protein kinase C-${\delta}$ (PKC-${\delta}$) in ALI has been a controversial topic. Here we investigated PKC-${\delta}$ function in ALI using PKC-${\delta}$ knockout (KO) mice and PKC inhibitors. Our results indicated that although the ability to produce proinflammatory mediators in response to LPS injury in PKC-${\delta}$ KO mice was similar to that of control mice, they showed enhanced recruitment of neutrophils to the lung and more severe pulmonary edema. PKC-${\delta}$ inhibition promoted barrier dysfunction in an endothelial cell layer in vitro, and administration of a PKC-${\delta}$-specific inhibitor significantly increased steady state vascular permeability. A neutrophil transmigration assay indicated that the PKC-${\delta}$ inhibition increased neutrophil transmigration through an endothelial monolayer. This suggests that PKC-${\delta}$ inhibition induces structural changes in endothelial cells, allowing extravasation of proteins and neutrophils.

• 한국세라믹학회지
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• 제31권12호
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• pp.1491-1500
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• 1994

Nonstoichiometry($\delta$) and the phase stability region of a ferrite spinel (Mg0.29Fe0.71)3-$\delta$O4 have been investigated by a coulometric titration method as a function of temperature(T) and oxygen partial pressure(Po2). It has been found that the spinel is thermodynamically stable in the ranges -8.0$\leq$log(PO2/atm)$\leq$-2.4, -7.0$\leq$log(PO2/atm)$\leq$-1.7 respectvely at 100$0^{\circ}C$. The nonstoichiometry extends over the ranges of -0.004$\leq$$\delta$$\leq$0.007, -0.008$\leq$$\delta$$\leq$0.006, -0.033$\leq$$\delta$$\leq$0.004 at 100$0^{\circ}C$, 120$0^{\circ}C$, respectvely. The observed PO2-dependence of $\delta$ suggests that the majority ionic defects are cation interstitials in the low PO2 region and cation vacancies in the high PO2 region.

• 대한기계학회논문집
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• 제9권1호
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• pp.1-9
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• 1985

본 연구에서는 이러한 점에도 역점을 두어서 초기 피로균열의 발생.거동을 관 찰하기 쉬운 연강을 선택하여 편진인장반복하중을 작용시켜, 연강 평골재의 표면상에 발생.성장하는 미소표면균열의 거동을 전자현미경과 광학현미경을 병용하여 표면과 파 단면을 입체적으로 조사하여, 피로균열의 초기발생상태를 조사하고, 그 성장율을 조사 하여 파괴역학적으로 해석하여 그 특성을 조사한다.

• 전자공학회논문지CI
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• 제39권4호
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• pp.19-27
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• 2002

역전파 알고리즘의 성능 개선을 위해서 학습율을 자동 조정하는 방식을 제안하였다. 제안한 방식은 각각의 연결강도의 학습율을 퍼지 논리 시스템을 이용하여 자동 조정하는 방식으로 각각의 연결강도에 대해서 ${\Delta}$와 $\bar{{\Delta}}$를 구하여 퍼지 논리 시스템의 입력으로 사용하고, 학습율을 출력으로 사용하였다. 제안한 방식을 N-패리티 문제, 함수 근사, 숫자 패턴 분류에 대한 시뮬레이션 결과 일반적인 역전파 알고리즘, 모멘텀 방식, Jacobs의 delta-bar-delta 방식보다 성능이 개선됨을 확인하였다.

• Journal of information and communication convergence engineering
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• 제1권3호
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• pp.157-162
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• 2003

We propose a learning method for improving the performance of the backpropagation algorithm. The proposed method is using a fuzzy logic system for automatic tuning of the learning rate of each weight. Instead of choosing a fixed learning rate, the fuzzy logic system is used to dynamically adjust the learning rate. The inputs of fuzzy logic system are delta and delta bar, and the output of fuzzy logic system is the learning rate. In order to verify the effectiveness of the proposed method, we performed simulations on the XOR problem, character classification, and function approximation. The results show that the proposed method considerably improves the performance compared to the general backpropagation, the backpropagation with momentum, and the Jacobs'delta-bar-delta algorithm.

• 제어로봇시스템학회논문지
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• 제6권2호
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• pp.121-126
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• 2000

In the fast sampling limit the delta operator model tends to the analog system model. This fundamental property of the delta operator model unifies continuous and discrete time control system. In this paper we study robust linear optimal model following servo system in the presence of disturbances and parameter perturbations. A technique to directly design the generalized differential operator based unified control system that covers both differential operator based continuous time and delta operator based discrete time case is presented. The quadratic criterion function for a linear system is used to design the robust unified servo control system The characteristics of the proposed servo system are analysed and simulated to verify the robustness.

• 대한전기학회논문지:전력기술부문A
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• 제48권6호
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• pp.747-752
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• 1999

In the fast sampling limit, the delta operator model tends to the analog system model. This fundamental property of the delta operator model unifies continuous and discrete time control system. In this paper, we study robust linear optimal model following servo system in the presence of disturbances and parameter perturbations. A technique to directly design the generalized differential operator based unified control system that convers both differential operator based continuous time and delta operator based discrete time case is presented. The quadratic criterion function for a linear system is used to design the robust unified servo control. The characteristics of the proposed servo system are analysed and simulated to verify the robustness.