• East Asian mathematical journal
• /
• 제32권5호
• /
• pp.729-744
• /
• 2016

A Crank-Nicolson characteristic finite element method is introduced to construct approximate solutions of a Sobolev equation with a convection term. The higher order of convergences in the temporal direction and in the spatial direction in $L^2$ normed space are verified for the Crank-Nicolson characteristic finite element method.

• Journal of applied mathematics & informatics
• /
• 제29권5_6호
• /
• pp.1205-1219
• /
• 2011

In this work, a stabilized characteristic finite volume method for the time-dependent Navier-Stokes equations is investigated based on the lowest equal-order finite element pair. The temporal differentiation and advection term are dealt with by characteristic scheme. Stability of the numerical solution is derived under some regularity assumptions. Optimal error estimates of the velocity and pressure are obtained by using the relationship between the finite volume and finite element methods.

• East Asian mathematical journal
• /
• 제38권3호
• /
• pp.293-319
• /
• 2022

In this paper, we introduce a higher order split least-squares characteristic mixed element scheme for Sobolev equations. First, we use a characteristic mixed element method to manipulate both convection term and time derivative term efficiently and obtain the system of equations in the primal unknown and the flux unknown. Second, we define a least-squares minimization problem and a least-squares characteristic mixed element scheme. Finally, we obtain a split least-squares characteristic mixed element scheme for the given problem whose system is uncoupled in the unknowns. We establish the convergence results for the primal unknown and the flux unknown with the second order in a time increment.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
• /
• pp.202-205
• /
• 2004

A numerical method is presented to determine the characteristic lengths for the failure analysis of composite joints without characteristic length tests. In the conventional methods, compressive characteristic length was determined from the result of a combined bearing test and finite element analysis. The present study, however, shows that the same compressive characteristic length can be obtained by numerical calculation without the bearing test. A new method to define the tensile characteristic length is also introduced so that the tensile characteristic length is numerically determined without the tensile test. Failure loads based on the numerically calculated characteristic lengths are validated by the test results for composite joints

• 대한전기학회논문지
• /
• 제36권9호
• /
• pp.685-690
• /
• 1987

Adaptive design of IIR digiral filters using equation error method has been studied. In this paper, a design technique of IIR digital filters using output error method with adaptive compensator is presented. In computer simulation results, it is shown that flat response characteristic in pass-band, below-40[dB] attenuation characteristic in stop-band, sharf cut-off characteristic in transition-band, and phase characteristic is linearin pass-band.

• Composites Research
• /
• 제16권4호
• /
• pp.10-21
• /
• 2003

본 논문에서는 특성길이 결정을 위해 시편에 가해지는 하중과 내부 응력분포의 관계가 거의 선형적으로 변한다는 특성을 이용하여. 실험을 수행하지 않고 복합재 체결부 파손해석을 위한 특성길이를 결정할 수 있는 방법을 제안하였다. 제안된 방법을 사용할 경우 특성길이 결정을 위한 실험 없이도 실험값을 사용한 결과와 동일한 압축특성길이를 얻을수 있음을 보였다. 압축특성길이 결정에서와 마찬가지로 실험 없이 인장특성길이를 결정하기 위해, 기존의 방법에서와 달리, 인장특성길이의 정의를 위해 사용하는 적층판의 강도값을, 원공이 없는 적층판의 값이 아닌 원공을 가진 적층판의 값을 사용하였다. 유한요소해석은 MSC/NASTRAN을 이용하였고, 체결재와 복합재의 접촉부는 접촉면 요소를 사용하여 모델링하였다. 제안된 방법으로 해석한 복합재 체결부의 파손하중은 Graphite/Epoxy 복합재료 체겯부의 실험 견과와 매우 잘 일치함을 확인하였다

• International Journal of Railway
• /
• 제3권1호
• /
• pp.14-18
• /
• 2010

This paper describes design and characteristic analysis of long primary type linear synchronous motor (LSM) for high speed train system. LSM is designed using loading distribution method and magnetic equivalent circuit. For characteristic analysis of LSM, analytical and numerical methods are applied. Analytical method for solving the magnetic field distribution of the analytic model is based on the Maxwell’s equations. Using the characteristic equation and magnetic equivalent circuit, we analyze the effect of variation of parameters, and then we validate the result by comparing with numerical method by finite element method (FEM). We compare the analytical method with numerical method for analyzing the effect by variable parameters. This result will be useful of design and forecast of performance without FEM.

• Water Engineering Research
• /
• 제5권4호
• /
• pp.177-183
• /
• 2004

This paper introduces an eigenvalue method of transforming the hyperbolic partial differential equations of a particular unsteady friction water hammer model into characteristic form. This method is based on the solution of the corresponding one-dimensional Riemann problem that transforms hyperbolic quasi-linear equations into ordinary differential equations along the characteristic directions, which in this case arises as the eigenvalues of the system. A mathematical justification and generalization of the eigenvalues method is provided and this approach is compared to the traditional characteristic method.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.197-197
• /
• 2000

In this paper, we present a novel method for design of fuzzy Logic controllers by defining a set of characteristic parameters (CFLCS). These parameters are extracted and defined by examining the structure and characteristics of the individual components of FLCs and parameterizing those. Based upon this formulation, a series of simulations is conducted for plants having simple dynamics in order to see the performance of this proposed method. The simplicity and effectiveness of this method are discussed in detail.

• 대한기계학회논문집
• /
• 제15권1호
• /
• pp.179-189
• /
• 1991

본 연구에서는 특성근이 같은 같은 경우의 기본해 유도에서 사용하였던 상사 방법을 이용하여, 균열끝 부근의 응력장과 변위장을 나타내고자 한다. 위의 해석을 바탕으로 개발한 프로그램의 정도에 대하여 검증하고, 이 프로그램을 복합재료 내의 균열 문제에 응용하여 응력확대계수에 관한 자료를 계산하고, 그 유용성을 검토하고자 한다.