• Journal of applied mathematics & informatics
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• 제33권3_4호
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• pp.351-363
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• 2015

In this paper, we investigate existence of solutions to a class of quadratic integral equation of Fredholm type in the space of functions with tempered moduli of continuity. Two numerical examples are given to illustrate our results.

• The Transactions of the Korean Institute of Electrical Engineers
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• 제44권4호
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• pp.483-489
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• 1995

To investigate the mechanism generated by irradiation in the insulator layer irradiated MIS (Metal - Insulator - Semiconductor) device, the various types of MIS capacitors depending on insulator thickness, insulator types and implanted impurities are fabricated on the P-type wafer. MIS capacitors exposed by 1Mrad Co$^{60}$ .gamma.-ray are measured for flat band voltage and charge density shifts pre- and post-irradiation. The measuring results of post-irradiation show the flat band voltage shifting toward negative direction and charge density increasing regardless of parameters. This results have a good agreement with calculated data by computer simulation. Si$_{3}$N$_{4}$ layers have a good radiation-hardness than SiO$_{2}$ layers compared to the results of post-irradiation. Also, radiation-induced negative trap is discovered in the implanted insulator layer. Using numerical analysis, four continuty equations (conduction-band electrons continuity equation, valence-band holes continuity equation, trapped electrons continuity equation, trapped holes continuity equation) are solved and charge distributions according to the distance and Si-Insulator interface states are investigated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.167-174
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• 1997

In this paper, the mathematical model of the hydraulic control valve is formulated, that is, this dynamic modeling which includes the motion equations and continuity equations can analyze the dynamic characteristics of the hydraulic control valve. The control valve for the transmission has the Over Speed Protection to protect a hydraulic travel motor. Therefore, this simulation shows the over speed protection and researches the main design parameters. The results of the computer simulation were assured through the experiment. From the comparison between both results, it is shown that this simulation program is useful and effective.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.74-79
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• 2001

A one-dimensional flood routing model was formulated to simulate the flood flow of drainage sub-canal using the continuity equation of paddy field and the momentum and continuity equation of drainage sub-canal. The model was applied for evaluating the hydraulic characteristics of drainage sub-canal at large-sized paddy fields. The model applicability was evaluated with field data and the simulated results were in good agreement with the observed data.

• Kyungpook Mathematical Journal
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• 제49권4호
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• pp.691-700
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• 2009

We use the fixed alternative theorem to establish Hyers-Ulam-Rassias stability of the quadratic functional equation where functions map a linear space into a complete quasi p-normed space. Moreover, we will show that the continuity behavior of an approximately quadratic mapping, which is controlled by a suitable continuous function, implies the continuity of a unique quadratic function, which is a good approximation to the mapping. We also give a few applications of our results in some special cases.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 춘계 학술대회논문집
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• pp.156-161
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• 1998

This describes a numerical method for predicting the incompressible unsteady laminar three-dimensional flows of fluid behaviour with free-surface. The elliptic differential equations governing the flows have been linearized by means of finite-difference approximations, and the resulting equations have been solved via a fully-implicit iterative method. The free-surface is defined by the motion of a set of marker particles and interface behaviour was investigated by way of a 'Lagrangian' technique. Using the GALA concept of Spalding, the conventional mass continuity equation is modified to form a volumetric or bulk-continuity equation. The use of this bulk-continuity relation allows the hydrodynamic variables to be computed over the entire flow domain including both liquid and gas regions. Thus, the free-surface boundary conditions are imposed implicitly and the problem formulation is greatly simplified. The numerical procedure is validated by comparing the predicted results of a periodic standing waves problems with analytic solutions or experimental results from the literature. The results show that this numerical method produces accurate and physically realistic predictions of three-dimensional free-surface flows.

• Journal of applied mathematics & informatics
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• 제31권3_4호
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• pp.491-498
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• 2013

This note is concerned with the uniform $L^p$-continuity of solution for the stochastic differential equations under Lipschitz condition and linear growth condition. Furthermore, uniform $L^p$-continuity of the solution for the stochastic functional differential equation is given.

• Journal of the Korean Institute of Telematics and Electronics
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• 제27권3호
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• pp.101-107
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• 1990

In this work, one-dimensional simulation is carried out for PT-GaAs Schottky barrier diodes with finite difference method. Shockley's semiconductor governing equations: Poisson equation and current continuity equation are discertized, and linearized by Newton-Raphson method. The linear system of equation is solved by Gaussian elimination method until convergence is achieved. The boundary condition for this equation is taken from thermionic emission-diffusion theory. Simulation is done for PT-GaAs epitaxial-layer Schottky barrier diodes. The claculated results of electron and potential distribution are shown. Simulation results show exellent agreement with experiments.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권1호
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• pp.29-33
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• 2014

In this paper, we report our numerical simulation on the electronic-optical properties of the phosphorescent organic light emitting diodes (PHOLEDs) devices. In order to calculate the electrical and optical characteristics such as the transport behavior of carriers, recombination kinetics, and emission property, we undertake the finite element method (FEM). Our model includes Poisson's equation, continuity equation to account for behavior of electrons and holes and the exciton continuity/transfer equation. We demonstrate that the refractive indexes of each material affect the emission property and the barrier height of the interface influences the behavior of charges and the generation of exciton.

• Kyungpook Mathematical Journal
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• 제61권3호
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• pp.559-581
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• 2021

In this paper, we establish the existence of solutions and the approximate controllability for the semilinear neutral differential control system under natural assumptions such as the local Lipschitz continuity of nonlinear term. First, we deal with the regularity of solutions of the neutral control system using fractional powers of operators. We also consider the approximate controllability for the semilinear neutral control equation, with a control part in place of a forcing term, using conditions for the range of the controller without the inequality condition as in previous results.