• Title/Summary/Keyword: Fokker-Plank equation

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Analysis of the fokker-plank equation for the dynamics of langevine cometitive learning neural network (Fokker-plank 방정식의 해석을 통한 Langevine 경쟁학습의 동역학 분석)

  • 석진욱;조성원
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.7
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    • pp.82-91
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    • 1997
  • In this paper, we analyze the dynamics of langevine competitive learning neural network based on its fokker-plank equation. From the viewpont of the stochastic differential equation (SDE), langevine competitive learning equation is one of langevine stochastic differential equation and has the diffusin equation on the topological space (.ohm., F, P) with probability measure. We derive the fokker-plank equation from the proposed algorithm and prove by introducing a infinitestimal operator for markov semigroups, that the weight vector in the particular simplex can converge to the globally optimal point under the condition of some convex or pseudo-convex performance measure function. Experimental resutls for pattern recognition of the remote sensing data indicate the superiority of langevine competitive learning neural network in comparison to the conventional competitive learning neural network.

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The Calculation of Seawater Exchange Rate in a Port by Numerical Analysis (수치해석을 이용한 항만의 해수교환율 산정)

  • Kim, Hyung-Jun;Kang, Gyu-Young;Cho, Yong-Sik
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.237-240
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    • 2008
  • Numerical Analysis for exchanging seawater experiment is carried out in Do-Jang fish port. The change of tidal velocity and water level is derived by the two-dimensional nonlinear shallow-water numerical model. To calculate exchange rate of seawater with the change of tidal velocity and water level, a two-dimensional numerical model is employed which governing equations are Fokker-Plank equations. The calculated exchange rates of each time are described in tables and figures.

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A study of global minimization analaysis of Langevine competitive learning neural network based on constraction condition and its application to recognition for the handwritten numeral (축합조건의 분석을 통한 Langevine 경쟁 학습 신경회로망의 대역 최소화 근사 해석과 필기체 숫자 인식에 관한 연구)

  • 석진욱;조성원;최경삼
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.466-469
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    • 1996
  • In this paper, we present the global minimization condition by an informal analysis of the Langevine competitive learning neural network. From the viewpoint of the stochastic process, it is important that competitive learning guarantees an optimal solution for pattern recognition. By analysis of the Fokker-Plank equation for the proposed neural network, we show that if an energy function has a special pseudo-convexity, Langevine competitive learning can find the global minima. Experimental results for pattern recognition of handwritten numeral data indicate the superiority of the proposed algorithm.

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Stochastic System Reduction and Control via Component Cost Analysis (구성요소치 해석을 이용한 확률계의 축소와 제어)

  • Chae, Kyo-Soon;Lee, Dong-Hee;Park, Sung-Man;Yeo, Un-Kyung;Cho, Yun-Hyun;Heo, Hoon
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.921-926
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    • 2007
  • A dynamic system under random disturbance is considered in the study. In order to control the system efficiently, proper reduction of system dimension is indispensible in design stage. The reduction method using component cost analysis in conjunction with stochastic analysis is proposed for the control of a system. System response is obtained in terms of dynamic moment equation via Fokker-Plank-Kolmogorov(F-P-K) equation. The dynamic moment response of the system under random disturbance are reduced by using of deterministic version of component cost analysis. The reduced system via proposed "stochastic component cost analysis" is successfully implemented for dynamic response and shows remarkable control performance effectively utilizing "stochastic controller" in physical time domain.

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Estimation of excitation and reaction forces for offshore structures by neural networks

  • Elshafey, Ahmed A.;Haddara, M.R.;Marzouk, H.
    • Ocean Systems Engineering
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    • v.1 no.1
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    • pp.1-15
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    • 2011
  • Offshore structures are subjected to wind loads, wind generated wave excitations, and current forces. In this paper we focus on the wind generated wave excitations as the main source for the external forces on the structure. The main objective of the paper is to provide a tool for using deck acceleration measurements to predict the value of the force and moment acting on the offshore structure foundation. A change in these values can be used as an indicator of the health of the foundation. Two methods of analysis are used to determine the relationship between the force and moment acting on the foundation and deck acceleration. The first approach uses neural networks while the other uses a Fokker-Planck formulation. The Fokker-Plank approach was used to relate the variance of the excitation to the variance of the deck acceleration. The total virtual mass of the equivalent SDOF of the structure was also determined at different deck masses.

Computation of viscoelastic flow using neural networks and stochastic simulation

  • Tran-Canh, D.;Tran-Cong, T.
    • Korea-Australia Rheology Journal
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    • v.14 no.4
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    • pp.161-174
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    • 2002
  • A new technique for numerical calculation of viscoelastic flow based on the combination of Neural Net-works (NN) and Brownian Dynamics simulation or Stochastic Simulation Technique (SST) is presented in this paper. This method uses a "universal approximator" based on neural network methodology in combination with the kinetic theory of polymeric liquid in which the stress is computed from the molecular configuration rather than from closed form constitutive equations. Thus the new method obviates not only the need for a rheological constitutive equation to describe the fluid (as in the original Calculation Of Non-Newtonian Flows: Finite Elements St Stochastic Simulation Techniques (CONNFFESSIT) idea) but also any kind of finite element-type discretisation of the domain and its boundary for numerical solution of the governing PDE's. As an illustration of the method, the time development of the planar Couette flow is studied for two molecular kinetic models with finite extensibility, namely the Finitely Extensible Nonlinear Elastic (FENE) and FENE-Peterlin (FENE-P) models.P) models.

A Study of Realizing Technique for Stochastic Controller (확률제어기의 실시간 적용을 위한 연구)

  • Kim, Y. K.;Lee, J. B.;Yoon, Y. S.;Choi, W. S.;Heo, H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.215-218
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    • 2002
  • A control strategy for a dynamic system under irregular disturbance by using stochastic controller is developed. In order to design stochastic controller, system dynamic model in real domain i transformed dynamic moment equation in stochastic domain by F-P-K approach. A study of real time control technique four stochastic controller is performed in this paper.

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A Experimental Study of Stochastic Controller Realizing Technique (실험적 연구를 통한 확률제어기 구현)

  • Lee, Jong-Bok;Kim, Yong-Kwan;Yoon, Young-Soo;Choi, Won-Seok;Heo, Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.715-718
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    • 2002
  • A control strategy for a dynamic system under Irregular disturbance by using stochastic controller is developed. In order to design stochastic controller. system dynamic model in real domain is transformed dynamic moment equation in stochastic domain by F-P-K approach. A study of real time control technique for stochastic controller is presented. The performance of stochastic controller is verified through experiment used by real time control technique method.

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A Study of 'Mode Selecting Stochastic Controller' for a Dynamic System Under Random Vibration

  • Kim Yong-Kwan;Lee Jong-Bok;Heo Hoon
    • Journal of Mechanical Science and Technology
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    • v.19 no.10
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    • pp.1846-1855
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    • 2005
  • This paper presents a new stochastic controller applied on the vibration control system under irregular disturbances based on the mode selection scheme. Measured displacement and frequency characteristics are simultaneously used in designing a mode selecting controller. This technique is validated by applying to the suppression problem of a flexible beam with randomly vibrated circumstances. The presented method, called Mode Selecting Stochastic Controller, uses the frequency measurement of the flexible system based on a Fast-Fourier transformation algorithm. This controller is constructed by combining mode selection method with previous known Stochastic Controller in real time: Numerical simulations and several experiments are conducted to validate the proposed method. The performance of the proposed method is compared with a stochastic controller developed recently. This method was improved compared with previous one.

A Study of Real Time Mode Selecting Stochastic Controller (실시간 모드 선택 확률제어기에 관한 연구)

  • Kim, Yong-Kwan;Lee, Jong-Bok;Yeo, Woon-ju;Heo, Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.1054-1057
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    • 2003
  • A Real Time Mode Selecting Stochastic Controller (RTMSSC) is developed as a new control strategy for a vibrating system under irregular disturbance. Displacement information and frequency characteristics obtained from me::id analysis of the system are used to design a Mode Selecting Controller. This Paper explains design technique of RTNSSC by applying it to the suppression of a flexible beam experiencing random vibration. The RTMSSC is designed by stochastic control from the modal information. The frequency information of the flexible system is utilized from the Mode Selecting Unit (MSU) based on a Fast-Fourier Transformation algorithm. The performance of the proposed technique, RTMSSC, is compared with that of Real Time Stochastic Controller developed recently, which show quite promising results.

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