• 대한수학회지
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• 제47권1호
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• pp.165-187
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• 2010

We introduce two numerical schemes for solving a system of ordinary differential equations which characterizes several kinds of linear reactions and diffusion from biochemistry, physiology, etc. The methods consist of sequential applications of the simple exact solver for a reversible reaction. We prove absolute stability and convergence of the proposed explicit methods. One is of first order and the other is of second order. Numerical results are included.

• 한국군사과학기술학회지
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• 제8권4호
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• pp.5-13
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• 2005

The impact of a long-rod penetrator into oblique plates with combined obliquity and yaw is investigated. The study was done using a newly developed three dimensional dynamic and impact analysis code, which uses the explicit finite element method. Through the comparison of simulation result with experimental result and other code's result, the adaptability and accuracy of the developed code is evaluated under the complex situation in which yaw angle and oblique angle exist simultaneously. As a result of comparison, it has found that deformed shape, residual length and velocity, rotational velocity of long-rod show good agreement with experimental data. Through this study, the applicability and accuracy of the code as a metallic armour system design tool is verified.

• 소성∙가공
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• 제18권3호
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• pp.229-235
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• 2009

This paper covers finite element simulations to evaluate the terminal crimping process of automobile electrical connector. Crimping is a classical technology process to ensure the electrical and the mechanical link between a wire and a terminal. Numerical modeling of the process is helpful to choose and to optimize the dimensions of the crimping part of the connector. In this paper, we discuss a 2D simulation of the crimping process, using explicit finite element methods (ABAQUS/Explicit) and we compare the results with experimental data from the industrial process of crimping (crimping height, crimping width and compressibility). The explicit method is preferred for the modeling of multi-contact problems, in spite of the quasi-static process of crimping. As compared with CAE analysis, a performance improvement makes certain of the truth of the matter.

• 수산해양기술연구
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• 제32권2호
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• pp.164-176
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• 1996

The main intention of this paper is to develop and compare the algorithm based on finite element procedures for nonlinear transient dynamic analysis which has combined effects of material and geometric nonlinearities. Incremental equilibrium equations based on the principle of virtual work are derived by the finite element approach. For the elasto - plastic large deformation analysis of shells and the determination of the displacement-time configuration under time-varying loads, the explicit, implicit and combined explicit-implicit time integration algorithm is adopted. In the time structure is selected and the results are compared with each others. Isoparametric 8-noded quadrilateral curved elements are used for shell structure in the analysis and for geometrically nonlinear elastic behaviour, a total Lagrangian coordinate system was adopted. On the other hands, material nonlinearity is based on elasto-plastic models with Von-Mises yield criteria. Thus, the combined explicit-implicit time integration algorithm is benefit in general case of shell structure, which is the result of this paper.

• ETRI Journal
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• 제36권4호
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• pp.609-616
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• 2014

Even though many computational methods (recursive formulae) for blocking probabilities in finite-capacity M/D/1 queues have already been produced, these are forms of transforms or are limited to single-node queues. Using a distinctly different approach from the usual queueing theory, this study introduces explicit (transform-free) formulae for a blocking probability, a stationary probability, and mean sojourn time under either production or communication blocking policy. Additionally, the smallest buffer capacity subject to a given blocking probability can be determined numerically from these formulae. With proper selection of the overall offered load ${\rho}$, the approach described herein can be applicable to more general queues from a computational point of view if the explicit expressions of random vector $D_n$ are available.

• Journal of Ship and Ocean Technology
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• 제7권3호
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• pp.34-55
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• 2003

Explicit Kutta condition approximation, proved useful in existing time-domain solver of the unsteady propeller problem, requires a specified functional behavior of the vorticity in space near the trailing edge. In this paper, the strength of the discrete vortices is controlled to have a specified behavior in space in the frequency domain approach. A new formulation is introduced and is implemented for analysis of a lifting surface of a rectangular planform. Sample computations carried out according to the new formulation compares well with that of existing unsteady lifting problem in the time domain.

• Korean Journal of Hydrosciences
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• 제7권
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• pp.107-124
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• 1996

Pipe design normally requires pump power, discharge or pipe diameter for each condition given. Due to several investigators the pipe friction factor con now be estimated by explicit way for a wide range of flow condition. In various problems of pipe design, however, the flow condition cannot be pre-determined even for a uniformly rough pipe. In these cases a lot of iterations are often required to have an accurate solution with ordinary approach. This paper presents the direct computation method of discharge and pipe diameter without any iteration process. Introducing the power law of friction factor, various non-dimensional physical numbers are derived such as power-diameter number, power-discharge number, diameter-slope number and discharge-slope number. One of the physical numbers concerned with discharge or pipe diameter can be related to a combination of the other in an explicit way.

• Steel and Composite Structures
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• 제13권6호
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• pp.561-570
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• 2012

Seismic collapse analysis requires efficient and automated method to perform thousands of time history analyses. The paper introduced the advantages of speed and convergence property of explicit method, provided a few techniques to accelerate speed of calculation and developed an automated procedure for collapse assessment, which combines the strong capacity of commercial explicit finite element software and the flexible, intelligent specialties of control program written in FORTRAN language aiming at collapse analysis, so that tedious and heavy work of collapse analysis based on FEMAP695 can be easily implemented and resource of calculation can be made the best use of. All the key commands of control program are provided to help analyzers and engineers to cope with collapse assessment conveniently.

• Steel and Composite Structures
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• 제13권6호
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• pp.539-560
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• 2012

This study uses an explicit numerical algorithm to evaluate the ultimate load capacity analysis of a unit Strarch frame, accounting for the initial imperfection effects of the stress-erection process. Displacement-based filament beam element and an explicit dynamic relaxation method with kinetic damping are used to achieve the analysis. The section is composed of the finite number of filaments that can be conveniently modeled by various material models. Ramberg-Osgood and bilinear kinematic elastic plastic material models are formulated to analyze the nonlinear material behaviors of filaments. The numerical results obtained in the present study are compared with the results of experiment for stress-erection and buckling of unit Strarch frames.

• International Journal of Advanced Culture Technology
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• 제7권3호
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• pp.158-165
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• 2019

Knowledge based system includes tools for constructing, testing, validating and refining the system along with user interfaces. An important issue in the design of a complete knowledge based system is the ability to produce explanations. Explanations are not just a series of rules involved in reasoning track. More detailed and explicit form of explanations is required not only for reliable reasoning but also for maintainability of the knowledge based system. This requires the explanation mechanisms to extend from knowledge oriented analysis to task oriented explanations. The explicit modeling of problem solving structures is suggested for explanation generation as well as for efficient and effective reasoning. Unlike other explanation scheme such as feedback explanation, the detailed, smaller and explicit representation of problem solving constructs can provide the system with capability of quality explanation. As a key step to development for explanation scheme, the problem solving methods are broken down into a finer grained problem solving primitives. The system records all the steps with problem solving primitives and knowledge involved in the reasoning. These are used to validate the conclusion of the consultation through explanations. The system provides user interfaces and uses specific templates for generating explanation text.