• Title/Summary/Keyword: approximation technique

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Acceleration of the Time-Dependent Radiative Transfer Calculations using Diffusion Approximation

  • Noh, Tae-Wan
    • Proceedings of the Korean Nuclear Society Conference
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    • 2004.10a
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    • pp.151-152
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    • 2004
  • An acceleration technique combined with the discrete ordinates method which has been widely used in the solution of neutron transport phenomena is applied to the solution of radiative transfer equation. The self-adjoint form of the second order radiation intensity equation is used to enhance the stability of the solution, and a new linearization method is developed to avoid the nonlinearity of the material temperature equation. This new acceleration method is applied to the well known Marshak wave problem, and the numerical result is compared with that of a non-accelerated calculation

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Terminal-pair reliability using flow augmenting path search algorithm

  • Choi, Moon-Soo;Jun, Chi-Hyuck
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1993.04a
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    • pp.136-145
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    • 1993
  • This paper considers a reliability problem as a special type of flow problem and presents an algorithm to evaluate the exact 2-terminal reliability of networks by using a backtracking technique. It employs a polygon-to-chain reduction in addition to series and parallel reduction techniques to reduce execution time. In comparisons, it presents a much better performance than other algorithms known to us. We also propose a methodology to apply the algorithm for approximation of the system reliability.

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Fiber orientation in the processing of polymer composites

  • Chung, Du-Hwan;Kwon, Tai-Hun
    • Korea-Australia Rheology Journal
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    • v.14 no.4
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    • pp.175-188
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    • 2002
  • We review the modeling and simulation of fiber orientation during injection molding processes of short fiber reinforced thermoplastics. Generally, a group of fibers are described in terms of probability distribution function or orientation tensor. Various closure approximation models to express higher order tensor in terms of Bower order tensors are reviewed. Rheology of fiber suspensions, multiple fiber-fiber interaction and numerical technique for the prediction of fiber orientation are also considered for concentrated situations.

QRS Recognition Using Attribute Grammar Interpreter (어트리뷰트 그래머 인터프리터를 이용한 QRS 인식)

  • 이병채;남승우
    • Journal of Biomedical Engineering Research
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    • v.12 no.2
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    • pp.121-130
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    • 1991
  • This paper presents a QRS recognition algorithm using attribute grammar and its interpreter. This system extracts primitive and their attributes by linear approximation technique and then represented linguistic formation using attribute grammar. These nonterminals and their attributes are evaluated by attribute grammar interpreter. The performance of the QRS recognition algorithm has been evaluated using arrhythmia simulator and CSE ECG library.

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A NONCONFORMING PRIMAL MIXED FINITE ELEMENT METHOD FOR THE STOKES EQUATIONS

  • Cho, Sungmin;Park, Eun-Jae
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.6
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    • pp.1655-1668
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    • 2014
  • In this article, we propose and analyze a new nonconforming primal mixed finite element method for the stationary Stokes equations. The approximation is based on the pseudostress-velocity formulation. The incompressibility condition is used to eliminate the pressure variable in terms of trace-free pseudostress. The pressure is then computed from a simple post-processing technique. Unique solvability and optimal convergence are proved. Numerical examples are given to illustrate the performance of the method.

A study on an effective tuning of a nonlinear state observer (비선형 상태 변수 관측기의 효과적인 이득 선정에 관한 연구)

  • 이훈구;탁민제
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.636-641
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    • 1993
  • Recent researches on control theory enable nonlinear state feedback which is more closer to real system without approximation. To apply nonlinear control theories, all state variables should be measured or estimated. In this paper, a technique of designing nonlinear state observer for a particular class of nonlinear system is presented. The result is applied to an aircraft model to prove the convergency of observation error.

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A SYSTEM OF NONLINEAR VARIATIONAL INCLUSIONS WITH (A, $\eta$)-MONOTONE MAPPINGS IN HILBERT SPACES

  • Shang, Meijuan;Qin, Xiaolong
    • East Asian mathematical journal
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    • v.24 no.1
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    • pp.1-6
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    • 2008
  • In this paper, we introduce a system of nonlinear variational inclusions involving (A, $\eta$)-monotone mappings in the framework of Hilbert spaces. Based on the generalized resolvent operator technique associated with (A, $\eta$)-monotonicity, the approximation solvability of solutions using an iterative algorithm is investigated. Our results improve and extend the recent ones announced by many others.

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Reliability computation technique for ball bearing under the stress-strength model

  • Nayak, S.;Seal, B.
    • International Journal of Reliability and Applications
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    • v.17 no.1
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    • pp.51-63
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    • 2016
  • Stress function of ball bearing is function of multiple stochastic factors and this system is so complex that analytical expression for reliability is difficult to obtain. To address this pressing problem, in this article, we have made an attempt to approximate system reliability of this important item based on reliability bounds under the stress strength setup. This article also provides level of error of this item. Numerical analysis has been adopted to show the closeness between the upper and lower bounds of this item.

A Study of Designing of Multi-Carrier CDMA System with Multi- Detector based on DGT

  • Kong, Hyung-Yun;Ho, Kwang-Chun
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1343-1345
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    • 2002
  • In this paper, we introduce the MC-CDMA (Multi-Carrier CDMA) system with MD (multi-detector). Due to unknown functional form of noise in wireless channel environments, it is not easy to design the detector through estimating the functional form of noise. Instead, we design the MD, which is constructed based on DGT (Data Grouping Technique) and quantiles estimated through RMSA (Robbins-Monro Stochastic Approximation) algorithm.

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AUXILIARY PRINCEPLE AND ERROR ESTIMATES FOR VARIATIONAL INEQUALITIES

  • NOOR, MUHAMMED ASLAM
    • Honam Mathematical Journal
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    • v.15 no.1
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    • pp.105-120
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    • 1993
  • The auxiliary principle technique is used to prove the uniqueness and the existence of solutions for a class of nonlinear variational inequalities and suggest an innovative iterative algorithm for computing the approximate solution of variational inequalities. Error estimates for the finite element approximation of the solution of variational inequalities are derived, which refine the previous known results. An example is given to illustrate the applications of the results obtained. Several special cases are considered and studied.

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