• Title/Summary/Keyword: Wiener processes

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Nonlinear Model Predictive Control Using a Wiener model in a Continuous Polymerization Reactor

  • Jeong, Boong-Goon;Yoo, Kee-Youn;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 1999.10a
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    • pp.49-52
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    • 1999
  • A subspace-based identification method of the Wiener model, consisting of a state-space linear block and a polynomial static nonlinearity at the output, is used to retrieve from discrete sample data the accurate information about the nonlinear dynamics. Wiener model may be incorporated into model predictive control (MPC) schemes in a unique way which effectively removes the nonlinearity from the control problem, preserving many of the favorable properties of linear MPC. The control performance is evaluated with simulation studies where the original first-principles model for a continuous MMA polymerization reactor is used as the true process while the identified Wiener model is used for the control purpose. On the basis of the simulation results, it is demonstrated that, despite the existence of unmeasured disturbance, the controller performed quite satisfactorily for the control of polymer qualities with constraints.

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CONSTRUCTION OF SOME PROCESSES ON THE WIENER SPACE ASSOCIATED TO SECOND ORDER OPERATORS

  • Cruzeiro, A.B.
    • Journal of the Korean Mathematical Society
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    • v.38 no.2
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    • pp.311-319
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    • 2001
  • We show that it is possible to associate diffusion processes to second order perturbations of the Ornstein-Uhlenbeck operator L on the Wiener space of the form L = L + 1/2∑L$^2$(sub)ξ(sub)$\kappa$ where the ξ(sub)$\kappa$ are "tangent processes" (i.e., semimartingales with antisymmetric diffusion coefficients).

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STOCHASTIC INTEGRAL OF PROCESSES TAKING VALUES OF GENERALIZED OPERATORS

  • CHOI, BYOUNG JIN;CHOI, JIN PIL;JI, UN CIG
    • Journal of applied mathematics & informatics
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    • v.34 no.1_2
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    • pp.167-178
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    • 2016
  • In this paper, we study the stochastic integral of processes taking values of generalized operators based on a triple E ⊂ H ⊂ E, where H is a Hilbert space, E is a countable Hilbert space and E is the strong dual space of E. For our purpose, we study E-valued Wiener processes and then introduce the stochastic integral of L(E, F)-valued process with respect to an E-valued Wiener process, where F is the strong dual space of another countable Hilbert space F.

On Presentable Approximation for Nonlinear Noise

  • Kang, Jie-Hyung
    • Journal of the Chungcheong Mathematical Society
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    • v.5 no.1
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    • pp.23-34
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    • 1992
  • This is an extension of results of Wiener's nonlinear noise theory from noises generated by the Wiener process to noises generated by processes with stationary Gaussian increments. In particular, using Nisio's Approach, we show that every measurable ergodic noise can be approximated in law by Gaussian process-presentable noise.

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Identification of the Relationship between Operating Conditions and Polymer Qualities in a Continuous Polymerization Reactor

  • Jeong, Boong-Goon;Yoo, Kee-Youn;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.501-506
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    • 1998
  • A mathematical model is developed to describe the relationship between the manipulated variables (e.g. jacket inlet temperature and feed flow rate) and the important qualities (e.g conversion and weight average molecular weight (Mw)) in a continuous polymerization reactor. The subspace-based identification method for Wiener model is used to retrieve from the discrete sample data the accurate information about both the structure and initial parameter estimates for iterative parameter optimization methods. The comparison of the output of the identified Wiener model with the outputs of a non-linear plant model shows a fairly satisfactory degree of accordance.

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Superior and Inferior Limits on the Increments of Gaussian Processes

  • Park, Yong-Kab;Hwang, Kyo-Shin;Park, Soon-Kyu
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.57-74
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    • 1997
  • Csorgo-Revesz type theorems for Wiener process are developed to those for Gaussian process. In particular, some results of superior and inferior limits for the increments of a Gaussian process are differently obtained under mild conditions, via estimating probability inequalities on the suprema of a Gaussian process.

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ON THE CONTINUITY AND GAUSSIAN CHAOS OF SELF-SIMILAR PROCESSES

  • Kim, Joo-Mok
    • Journal of the Chungcheong Mathematical Society
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    • v.12 no.1
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    • pp.133-146
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    • 1999
  • Let {X(t), $t{\geq}0$} be a stochastic integral process represented by stable random measure or multiple Ito-Wiener integrals. Under some conditions, we prove the continuity and self-similarity of these stochastic integral processes. As an application, we get Gaussian chaos which has some shift continuous function.

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Single Step Response Based Method for the Simple Identification of Wiener-type Nonlinear Process (단일 계단 응답에 근거한 Wiener형 비선형 공정의 간편한 모델 확인 방법)

  • Sanghun Lim;Jea Pil Heo;Su Whan Sung;Jietae Lee;Friedrich Y. Lee
    • Korean Chemical Engineering Research
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    • v.61 no.1
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    • pp.89-96
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    • 2023
  • The Wiener-type nonlinear model where a static nonlinear block follows a dynamic linear block is widely used to describe the dynamics of chemical processes. A long process excitation step is typically needed to identify this Wiener-type nonlinear model with two blocks. In order to cope with this disadvantage, an identification method for the Wiener-type nonlinear model that uses only a single-step response is proposed here. The proposed method estimates the response of the dynamic linear sub-block from the initial part of the step response, and then the static nonlinear sub-block is identified. Because the only single-step response is used to identify the Wiener-type nonlinear model, there is great benefit in time and cost for obtaining process response. The performance of the proposed identification method with the single-step response is verified through a representative Wiener-type nonlinear process, a pH titration process, and a liquid level system.

A Wong-Zakai Type Approximation for the Multiple Ito-Wiener Integral

  • Lee, Kyu-Seok;Kim, Yoon-Tae;Jeon, Jong-Woo
    • Proceedings of the Korean Statistical Society Conference
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    • 2002.05a
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    • pp.55-60
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    • 2002
  • We present an extension of the Wong-Zakai type approximation theorem for a multiple stochastic integral. Using a piecewise linear approximation $W^{(n)}$ of a Wiener process W, we prove that the multiple integral processes {${\int}_{0}^{t}{\cdots}{\int}_{0}^{t}f(t_{1},{\cdots},t_{m})W^{(n)}(t_{1}){\cdots}W^{(n)}(t_{m}),t{\in}[0,T]$} where f is a given symmetric function in the space $C([0,T]^{m})$, converge to the multiple Stratonovich integral of f in the uniform $L^{2}$-sense.

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