• 산업공학
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• 제10권3호
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• pp.167-177
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• 1997

This paper deals with an application of process value analysis method for a manufacturing process in order to redesign facility layout in a paper company. We have used the value analysis method which permits an overall and rigorous study of process by a functional approach. Firstly, customer's expectations for the future process are clearly and precisely expressed with specifications of the Functional Extern Analysis. The existing process is analyzed using various tool of the Functional Internal Analysis in the second part. From the results of these analysis, we find out that the main problems of current facility are due to scheduling and facility layout. This paper is devoted to resolve the second problem. We suggest an ideal solution in order to have a reference solution. Nextly, We give realistic choices and the final solution for the facility layout.

• 대한수학회지
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• 제59권2호
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• pp.279-298
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• 2022

In this paper, the existence and uniqueness for the global solution of neutral stochastic functional differential equation is investigated under the locally Lipschitz condition and the contractive condition. The implicit iterative methodology and the Lyapunov-Razumikhin theorem are used. The stability analysis for such equations is also applied. One numerical example is provided to illustrate the effectiveness of the theoretical results obtained.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2003년도 춘계 학술발표회 논문집
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• pp.31-36
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• 2003

Using a short time expansion of the fundamental solution of heat equation by analysis of Wiener functional with the help of Malliavin calculus, we obtain the asymptotic expansion of the mean distance of Brownian motion on Riemannian manifolds.

• Nonlinear Functional Analysis and Applications
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• 제26권5호
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• pp.869-885
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• 2021

In this article, we define Picard's three-step iteration process for the approximation of fixed points of Zamfirescu operators in an arbitrary Banach space. We prove a convergence result for Zamfirescu operator using the proposed iteration process. Further, we prove that Picard's three-step iteration process is almost T-stable and converges faster than all the known and leading iteration processes. To support our results, we furnish an illustrative numerical example. Finally, we apply the proposed iteration process to approximate the solution of a mixed Volterra-Fredholm functional nonlinear integral equation.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.295-309
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• 2010

In this paper, we study delayed high-order Cohen-Grossberg neural networks with reaction-diffusion terms and Neumann boundary conditions. By using inequality techniques and constructing Lyapunov functional method, some sufficient conditions are given to ensure the existence and convergence of the periodic oscillatory solution. Finally, an example is given to verify the theoretical analysis.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제27권1호
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• pp.23-36
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• 2023

The vector wave equation is widely used in electromagnetic wave analysis. This paper solves the vector wave equation using curl-conforming finite elements. The variational problem is established from Riesz functional based on vector wave equation and the unique existence of weak solution is explored. The edge elements are used in computation and the simulation results are compared with those obtained from a commercial simulator, ANSYS HFSS (high-frequency structure simulator).

• Environmental Engineering Research
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• 제19권2호
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• pp.157-163
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• 2014

The adsorption of Cr(VI) from aqueous solutions to activated carbon fiber (ACF) was investigated using both batch and flow-through column experiments. The batch experiments (adsorbent dose, 10 g/L; initial Cr(VI) concentration, 5-500 mg/L) showed that the maximum adsorption capacity of Cr(VI) to ACF was determined to 20.54 mg/g. The adsorption of Cr(VI) to ACF was sensitive to solution pH, decreasing from 9.09 to 0.66 mg/g with increasing pH from 2.6 to 9.9; the adsorption capacity was the highest at the highly acidic solution pHs. Kinetic model analysis showed that the Elovich model was the most suitable for describing the kinetic data among three (pseudo-first-order, pseudo-second-order, and Elovich) models. From the nonlinear regression analysis, the Elovich model parameter values were determined to be ${\alpha}$ = 162.65 mg/g/h and ${\beta}$ = 2.10 g/mg. Equilibrium isotherm model analysis demonstrated that among three (Langmuir, Freundlich, Redlich-Peterson) models, both Freundlich and Redlich-Peterson models were suitable for describing the equilibrium data. In the model analysis, the Redlich-Peterson model fit was superimposed on the Freundlich fit. The Freundlich model parameter values were determined to be $K_F$ = 0.52 L/g and 1/n = 0.56. The flow-through column experiments showed that the adsorption capacities of ACF in the given experimental conditions (column length, 10 cm; inner diameter, 1.5 cm; flow rate, 0.5 and 1.0 mL/min; influent Cr(VI) concentration, 10 mg/L) were in the range of 2.35-4.20 mg/g. This study demonstrated that activated carbon fiber was effective for the removal of Cr(VI) from aqueous solutions.

• Nonlinear Functional Analysis and Applications
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• 제26권1호
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• pp.65-70
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• 2021

We characterize the solution set for a second-order cone linear fractional optimization problem (P). We present sequential Lagrange multiplier characterizations of the solution set for the problem (P) in terms of sequential Lagrange multipliers of a known solution of (P).

• Korean Journal of Mathematics
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• 제21권3호
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• pp.345-350
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• 2013

Some results on the sensitivity of the solution of the generalized Lyapunov equation $$A^{n-1}X+A^{n-2}XA^*+{\cdots}+X(A^*)^{n-1}=B$$ are shown follow easily from well-known theorems in functional analysis.

• 대한임상검사과학회지
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• 제53권1호
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• pp.19-31
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• 2021

이 연구의 목적은 기능적, 정량적 분석을 바탕으로 수입 LX 세정액(LX-CS)과 자가제조 OC 세정액(OC-CS)의 성능을 비교하였다. 기능적 분석은 ADC값을 사용하여 평가하였다. 정량적 분석을 위해 CLSI 지침에 따라 정도 관리 물질을 이용하여 정밀도, 직선성 및 오염률을 평가하였다. OC-Sensor PLEDIA(Eiken Chemical, Japan)를 이용한 모든 cuvette의 ADC값은 허용기준을 만족하였다. 정량적 분석의 경우 두 제품의 정밀도는 5.0% 미만이었고, 오염율은 ±1.00% 이하였다. 직선성 기울기와 r2 값은 LX-CS에서 각각 1.0017와 0.9982였으며, OC-CS에서 0.9924와 0.9996이였다. 상관계수(r)는 0.9997이였다. 또한 40개의 가변을 이용한 % difference는 10% 미만, P값은 0.1 미만이였다. 각 각 차이: 표준 편차 비(D: ±1 SD 비)에 기초한 두 제품 모두 유사한 결과를 보였다. 결론적으로 두 제품의 기능적, 정량적 분석을 비교한 결과 유사하였다. 향후 자가제조한 OC세정액은 수입 LX세정액보다 훨씬 더 안정적이고 빠른 공급을 제공할 수 있을 것이라 기대된다.