• Title/Summary/Keyword: iterative processes

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Ishikawa-Type And Mann-Type Iterative Processes With Errors For m-Accretive Operators

  • Park, Jong-Yeoul;Jeong, Jae-Ug
    • Communications of the Korean Mathematical Society
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    • v.15 no.2
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    • pp.309-323
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    • 2000
  • The purposes of this paper are to revise the definitions of Ishikawa and Mann type iterative processes with errors, to study the unique solution of the m-accretive operator equation x+Tx=f and the convergence problem of Ishikawa and Mann type iterative processes with errors for m-accretive mappings without the Lipschitz condition. The results presented in this paper improve, extend, and unify the corresponding results in [4, 7, 8, 12, 16] in more general setting.

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Iterative identification methods for ill-conditioned processes

  • Lee, Jietae;Cho, Wonhui;Edgar, Thomas F.
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1762-1765
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    • 1997
  • Some ill-conditioned processes are very sensitive to small element-wise uncertainties arising in classical element-by-element model identifications. For such processes, accurate identification of simgular values and right singular vectors are more important than theose of the elements themselves. Singular values and right singular vectors can be found by iteraive identification methods which implement the input and output transformations iteratively. Methods based on SVD decomposition, QR decomposition and LU decomposition are proposed and compared with the Kuong and Mac Gregor's method. Convergence proofs are given. These SVD and QR mehtods use normal matrices for the transformations which cannot be calculated analytically in general and so they are hoard to apply to dynamic processes, whereas the LU method used simple analyitc transformations and can be directly applied to dynamic processes.

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LOCATING ROOTS OF A CERTAIN CLASS OF POLYNOMIALS

  • Argyros, Ioannis K.;Hilout, Said
    • East Asian mathematical journal
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    • v.26 no.3
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    • pp.351-363
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    • 2010
  • We introduce a special class of real recurrent polynomials $f_m$$($m{\geq}1$) of degree m+1, with positive roots $s_m$, which are decreasing as m increases. The first root $s_1$, as well as the last one denoted by $s_{\infty}$ are expressed in closed form, and enclose all $s_m$ (m > 1). This technique is also used to find weaker than before [6] sufficient convergence conditions for some popular iterative processes converging to solutions of equations.

PERTURBED THREE-STEP ITERATIVE PROCESSES WITH ERRORS FOR GENERAL STRONGLY NONLINEAR QUASIVARIATIONAL INEQUALITIES

  • ZHAO YALI;XIA ZUNQUAN;LIU ZEQING;KANG SHIN MIN
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.171-183
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    • 2005
  • In this paper, we introduce and study a class of general strongly nonlinear quasivariational inequalities in Hilbert spaces. We prove the existence and uniqueness of solution and convergence of the perturbed the three-step iterative sequences with errors for this kind of general strongly nonlinear quasivariational inquality problems involving relaxed Lipschitz, relaxed monotone, and strongly monotone mappings. Our results extend, improve, and unify many known results due to Liu-Ume-Kang, Kim-Kyung, Zeng and others.

Model predictive control combined with iterative learning control for nonlinear batch processes

  • Lee, Kwang-Soon;Kim, Won-Cheol;Lee, Jay H.
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.299-302
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    • 1996
  • A control algorithm is proposed for nonlinear multi-input multi-output(MIMO) batch processes by combining quadratic iterative learning control(Q-ILC) with model predictive control(MPC). Both controls are designed based on output feedback and Kalman filter is incorporated for state estimation. Novelty of the proposed algorithm lies in the facts that, unlike feedback-only control, unknown sustained disturbances which are repeated over batches can be completely rejected and asymptotically perfect tracking is possible for zero random disturbance case even with uncertain process model.

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Advanced Control Techniques for Batch Processes Based on Iterative Learning Control Methods (반복학습제어를 기반으로 한 회분공정의 고급제어기법)

  • Lee, Kwang Soon
    • Korean Chemical Engineering Research
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    • v.44 no.5
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    • pp.425-434
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    • 2006
  • The operability and productivity of continuous processes, especially in petrochemical industries have made remarkable improvement during the past twenty years through advanced process control (APC) typified by model-based predictive control. On the other hand, APC have not been actively practiced in industrial batch processes typified by batch polymerization reactors. Perhaps the main cause for this has been the lack of reliable batch process APC techniques that can overcome the unique problems in industrial batch processes. Recently, some noteworthy progress is being made in this area. New high-performance batch process control techniques that can accommodate and also overcome the unique problems of industrial batch processes have been proposed on the basis of iterative learning control (ILC). In this review paper, recent advancement in the batch process APC techniques are presented, with a particular focus on the variations of the so called Q-ILC method, with the hope that they are widely practiced in different industrial batch processes and enhance their operations.

Numerical Solution of Riccati Differential Equation in Optimal Control Theory (최적제어이론과 관련된 "리카티" 미분방정식의 수식해)

  • 경규학
    • Journal of the Korean Operations Research and Management Science Society
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    • v.9 no.2
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    • pp.28-33
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    • 1984
  • In this paper some procedures are given whereby an analytic solution may be found for the Riccati differential equation and algebraic Riccati equation in optimal control theory. Some iterative techniques for solving these equations are presented. Rate of convergence and initialization of the iterative processes are discussed.

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NUMERICAL METHODS SOLVING THE SEMI-EXPLICIT DIFFERENTIAL-ALGEBRAIC EQUATIONS BY IMPLICIT MULTISTEP FIXED STEP SIZE METHODS

  • Kulikov, G.Yu.
    • Journal of applied mathematics & informatics
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    • v.4 no.2
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    • pp.341-378
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    • 1997
  • We consider three classes of numerical methods for solv-ing the semi-explicit differential-algebraic equations of index 1 and higher. These methods use implicit multistep fixed stepsize methods and several iterative processes including simple iteration, full a2nd modified Newton iteration. For these methods we prove convergence theorems and derive error estimates. We consider different ways of choosing initial approximations for these iterative methods and in-vestigate their efficiency in theory and practice.

APPROXIMATIONS OF THE ITERATIVE SEQUENCES FOR ASYMPTOTICALLY NONEXPANSIVE MAPPINGS IN BANACH SPACES

  • Chang, Shih-Sen;Cho, Yeol-Je;Zhou, Haiyun
    • East Asian mathematical journal
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    • v.24 no.1
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    • pp.125-137
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    • 2008
  • In this paper, we first introduce some iterative sequences of Halpern type for asymptotically nonexpansive mappings and nonexpansive mappings in Banach spaces and then we discuss strong convergence for the iterative processes. The results presented in this paper extend, supplement and improve the correspoding main results of Reich [11], Shimizu and Takahashi [13], Shioji and Takahashi [15], [16] and Wittmann [18].

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Example of iterative process in upcycled clothing design: Unused neckties and upholstery scraps

  • Koca, Emine;Koc, Fatma
    • The Research Journal of the Costume Culture
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    • v.28 no.6
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    • pp.890-911
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    • 2020
  • This study proposed a base framework for creating sustainable designs with textile production waste and unused neckties with the "design thinking" approach, which is an iterative process. It aimed to set an example of how fashion designers can plan and manage their clothing design processes in a more sustainable way by recycling textile production scraps and unused neckties into unique clothing pieces with the upcycling method. Unused neckties and upholstery scraps were turned into skirts, blouses, and dresses by using creative techniques in line with current fashion trends. In addition, the five-stage iterative design process followed was explained, and the way in which the waste textile materials gained value by being converted into unique garments was discussed in terms of the user and the designer. Through the study, it was observed that the smallest amount of textile waste can be transformed into upcycled clothing via the iterative process, and original, value-added products enjoyed by consumers can be created. In addition, it was observed that the design thinking approach improves the understanding of the context of the problem, creativity in the generation of insights and solutions, skills to materialize those solutions through iterative prototyping, and the ability to combine these factors. Promising ideas to help designers develop recycling strategies were also provided.