• Title/Summary/Keyword: coupled problem

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An Analytic Solution to Projector Pose Estimation Problem

  • Lee, Joo-Haeng
    • ETRI Journal
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    • v.34 no.6
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    • pp.978-981
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    • 2012
  • We present an analytic solution to the projector pose estimation problem for the pinhole projection model in which the source image is a centered rectangle with an unknown aspect ratio. From a single quadrilateral given as a target image, our solution gives the position and orientation of a projector as well as the aspect ratio of a source image. The proposed method decomposes the problem into two pose estimation problems of coupled line projectors aligned at each diagonal of the given quadrilateral and then computes the common solution that satisfies the relevant geometric constraints. The solution is formulated as simple analytic equations. We also provide a determinant of projectability of an arbitrary quadrilateral.

OPTIMAL CONTROL OF SYSTEMS OF PARABOLIC PDES IN EXPLOITATION OF OIL

  • Li, Chunfa;Feng, Enmin;Liu, Jinwang
    • Journal of applied mathematics & informatics
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    • v.13 no.1_2
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    • pp.247-259
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    • 2003
  • Optimal control problem for the exploitaton of oil is investigated. The optimal control problem under consideration in this paper is governed by weak coupled parabolic PDEs and involves with pointwise state and control constraints. The properties of solution of the state equations and the continuous dependence of state functions on control functions are investigated in a suitable function space; existence of optimal solution of the optimal control problem is also proved.

Analysis of body sliding along cable

  • Kozar, Ivica;Malic, Neira Toric
    • Coupled systems mechanics
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    • v.3 no.3
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    • pp.291-304
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    • 2014
  • Paper discusess a dynamic engineering problem of a mass attached to a pendulum sliding along a cable. In this problem the pendulum mass and the cable are coupled together in a model described by a system of differential algebraic equations (DAE). In the paper we have presented formulation of the system of differential equations that models the problem and determination of the initial conditions. The developed model is general in a sense of free choice of support location, elastic cable properties, pendulum length and inclusion of braking forces. Examples illustrate and validate the model.

Mixed H$_2$H$\infty$and $\mu$-synthesis Approach to Coupled Three-Inertia Benchmark Problem (혼합 H$_2$H$\infty$$\mu$-이론을 이용한 벤치마크 문제의 해법)

  • 최연욱
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.22-22
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    • 2000
  • This study investigates the use of mixed $H_2/H_{\infty}$ and $\mu$-synthesis to construct a robust controller for the benchmark problem. The model treated in the problem is a coupled three-inertia system which reflects the dynamics of mechanical vibrations. We, first adopt the mixed $H_2/H_{\infty}$ the to design a feedback controller K(s). Next, $\mu$-synthesis method is applied to the overall system to make use of structured parametric uncertainty.

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A computational setting of calcium leaching in concrete and its coupling with continuum damage mechanics

  • Nguyen, V.H.;Nedjar, B.;Torrenti, J.M.
    • Computers and Concrete
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    • v.1 no.2
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    • pp.131-150
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    • 2004
  • We present in this work a coupled phenomenological chemo-mechanical model that represents the degradation of concrete-like materials. The chemical behaviour is described by the nowadays well known simplified calcium leaching approach. And the mechanical damage behaviour is described by a continuum damage model which involves the gradient of the damage quantity. The coupled nonlinear problem at hand is addressed within the context of the finite element method. For the equation governing the calcium dissolution-diffusion part of the problem, special care is taken to treat the highly nonlinear calcium conductivity and solid calcium functions. The algorithmic design is based on a Newton-type iterative scheme where use is made of a recently proposed relaxed linearization procedure. And for the equation governing the damage part of the problem, an augmented Lagrangian formulation is used to take into account the damage irreversibility constraint. Finally, numerical simulations are compared with experimental results on cement paste.

Development of Part Sales Agent Coupled with Virtual Manufacturing in Internet Environment (인터넷상의 가상생산 기반 부품판매 에이전트 개발)

  • Choi, Hyung-Rim;Kim, Hyun-Soo;Park, Young-Jae;Park, Byoung-Joo;Lee, Kyoung-Jun
    • Asia pacific journal of information systems
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    • v.12 no.4
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    • pp.193-213
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    • 2002
  • The sales activity of most of small manufacturing companies is based on orders of buyers. The process of promotion, negotiation, receipt and selection of orders of the manufacturers is closely coupled with the load status of the production lines. The decision on whether to accept an order or not, or the selection of optimal order set among excessive orders is entirely dependent on the schedule of production lines. However, in the real world, since the production scheduling activity is mainly performed by human experts, most of small manufacturers are suffer from being unable to meet due dates, lack of rapid decision on the acceptance of new order. Recently, Internet based Electronic Commerce is recognized as one of the alternatives for strengthening sales power of small and medium companies. However, small and medium manufacturers can't adjust properly to the new environment because they are in short of money, personnel, and technology. To cope with this problem, this paper deals with development of part sales agent coupled with virtual manufacturing in Internet environment that consist of selection agent, advertisement agent, selection agent, negotiation agent, and virtual manufacturing system. This paper develops a time-bounded negotiation mechanism for small and medium manufacturers in agent-based automated negotiation between customers and negotiation agents. Furthermore, to select optimal order set maximized profit, we first formulate the order selection problem with mixed integer programming, but the computation time of IP is not acceptable for real world scale problem. To overcome this problem and dynamic nature of virtual manufacturing, we suggest a genetic algorithm approach, which shows a reasonable computation time for real world case and good incremental problem solving capability.

Approximately Coupled Method of Finite Element Method and Boundary Element Method for Two-Dimensional Elasto-static Problem (이차원 탄성 정적 문제를 위한 유한요소법과 경계요소법의 근사 결합 방법)

  • Song, Myung-Kwan
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.3
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    • pp.11-20
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    • 2021
  • In this paper, the approximately coupled method of finite element method and boundary element method to obtain efficient and accurate analysis results is proposed for a two-dimensional elasto-static problem with a geometrically abruptly changing part. As the finite element of a two-dimensional problem, three-node and four-node plane stress element is applied, and as the boundary element of a two-dimensional problem, three-node boundary element is applied. In the modeling stage, firstly, an entire analysis target object is modeled as finite elements, and then a geometrically abruptly changing part is modeled as boundary elements. The boundary element is defined using the nodes defined for modeling finite elements. In the analysis stage, finite element analysis is firstly performed on a entire analysis target object, and boundary element analysis is automatically performed afterwards. As for the boundary conditions at boundary element analysis, displacement conditions and stress conditions, which are the results of finite element analysis, are applied. As a numerical example, the analysis results for a two-dimensional elasto-static problem, a plate with a crack, are presented and investigated.

Free Vibration Analysis of Two Identical Rectangular Plates Coupled with Fluid (유체로 연성된 동일한 두 직사각 평판의 고유진동 해석)

  • Jeong, Kyeong-Hoon;Lee, Seong-Cheol;Yoo, Gye-Hyoung
    • Journal of the Korean Society of Safety
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    • v.17 no.2
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    • pp.8-15
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    • 2002
  • In order to investigate the vibration characteristics of fluid-structure interaction problem, we modeled two identical rectangular plates coupled with fluid. A commercial computer code, ANSYS was used to perform finite element analysis and FEM solutions were compared with the experimental results to verify the finite element model. As a result, comparison of FEM and experiment showed good agreement, and the transverse vibration modes, in-phase and out-of-Phase, were observed alternately in the fluid-coupled system. The effect of fluid gap size on the fluid-coupled natural frequency were investigated. It was shown that the mode numbers increased, the normalized natural frequencies monotonically increased. And it was also found that an increase of the fluid gap reduced the coupled natural frequencies for the in-phase modes but increased the coupled natural frequencies for the out-of phase modes, and eventually converged to the results of an infinite fluid gap.

A fully coupled thermo-poroelastoplasticity analysis of wellbore stability

  • Zhu, Xiaohua;Liu, Weiji;Zheng, Hualin
    • Geomechanics and Engineering
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    • v.10 no.4
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    • pp.437-454
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    • 2016
  • Wellbore instability problem is one of the main problems that met frequently during drilling, particularly in high temperature, high pressure (HPHT) formations. There are large amount of researches about wellbore stability in HPHT formations, which based on the thermo-poroelastic theory and some achievements were obtained; however, few studies have investigated on the fully coupled thermo-poroelastoplasticity analysis of wellbore stability, especially the analysis of wellbore stability while the filter cake formed. Therefore, it is very necessary to do some work. In this paper, the three-dimensional wellbore stability model which overall considering the effects of fully coupled thermo-poroelastoplasticity and filter cake is established based on the finite element method and Drucker-Prager failure criterion. The distribution of pore pressure, wellbore stress and plastic deformation under the conditions of different mud pressures, times and temperatures have been discussed. The results obtained in this paper can offer a great help on understanding the distribution of pore pressure and wellbore stress of wellbore in the HPHT formation for drilling engineers.

Research on parallelization mechanism of inductively coupled plasma for large area plasma source

  • Lee, Jang-Jae;Kim, Si-Jun;Kim, Gwang-Gi;Lee, Ba-Da;Lee, Yeong-Seok;Yeom, Hui-Jung;Kim, Dae-Ung;Yu, Sin-Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.183-183
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    • 2016
  • Inductively coupled plasma having the high-density is often used for high productivity in the plasma processing. In large area processing, the plasma can be generated by using the multi-pole connected in parallel. However, in case of this, the power cannot transfer to plasma uniformly. To address the problem, we studied the mechanism of inductively coupled plasma connected in parallel by using transformer model. We also studied about the change of the plasma parameters over the time through the power balance equation and particle balance equation.

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