• Title/Summary/Keyword: Iterative algorithm

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ITERATIVE ALGORITHM FOR RANDOM GENERALIZED NONLINEAR MIXED VARIATIONAL INCLUSIONS WITH RANDOM FUZZY MAPPINGS

  • Faizan Ahmad, Khan;Eid Musallam, Aljohani;Javid, Ali
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.4
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    • pp.881-894
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    • 2022
  • In this paper, we consider a class of random generalized nonlinear mixed variational inclusions with random fuzzy mappings and random relaxed cocoercive mappings in real Hilbert spaces. We suggest and analyze an iterative algorithm for finding the approximate solution of this class of inclusions. Further, we discuss the convergence analysis of the iterative algorithm under some appropriate conditions. Our results can be viewed as a refinement and improvement of some known results in the literature.

Application of ICP(Iterative Closest Point) Algorithm for Optimized Registration of Object Surface and Unfolding Surface in Ship-Hull Plate Forming (선박 외판 성형에서 목적 형상과 전개 평판의 최적 정합을 위한 ICP(Iterative Closest Point) 알고리즘 적용)

  • Lee, Jang-Hyun;Yoon, Jong-Sung;Ryu, Cheol-Ho;Lee, Hwang-Beom
    • Korean Journal of Computational Design and Engineering
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    • v.14 no.2
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    • pp.129-136
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    • 2009
  • Generally, curved surfaces of ship hull are deformed by flame bending (line heating), multi-press forming, and die-less forming method. The forming methods generate the required in-plane/bending strain or displacement on the flat plate to make the curved surface. Multi-press forming imposes the forced displacements on the flat plate by controlling the position of each pressing points based upon the shape difference between the unfolded flat plate and the curved object shape. The flat plate has been obtained from the unfolding system that is independent of the ship CAD. Apparently, the curved surface and the unfolded-flat surface are expressed by different coordinate systems. Therefore, one of the issues is to find a registration of the unfolded surface and the curved shape for the purpose of minimum amount of forming works by comparing the two surfaces. This paper presents an efficient algorithm to get an optimized registration of two different surfaces in the multi-press forming of ship hull plate forming. The algorithm is based upon the ICP (Iterative Closest Point) algorithm. The algorithm consists of two iterative procedures including a transformation matrix and the closest points to minimize the distance between the unfolded surface and curved surfaces. Thereby the algorithm allows the minimized forming works in ship-hull forming.

A Second-Order Iterative Learning Algorithm with Feedback Applicable to Nonlinear Systems (비선형 시스템에 적용가능한 피드백 사용형 2차 반복 학습제어 알고리즘)

  • 허경무;우광준
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.5
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    • pp.608-615
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    • 1998
  • In this paper a second-order iterative learning control algorithm with feedback is proposed for the trajectory-tracking control of nonlinear dynamic systems with unidentified parameters. In contrast to other known methods, the proposed teaming control scheme utilize more than one past error history contained in the trajectories generated at prior iterations, and a feedback term is added in the learning control scheme for the enhancement of convergence speed and robustness to disturbances or system parameter variations. The convergence proof of the proposed algorithm is given in detail, and the sufficient condition for the convergence of the algorithm is provided. We also discuss the convergence performance of the algorithm when the initial condition at the beginning of each iteration differs from the previous value of the initial condition. The effectiveness of the proposed algorithm is shown by computer simulation result. It is shown that, by adding a feedback term in teaming control algorithm, convergence speed, robustness to disturbances and robustness to unmatched initial conditions can be improved.

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A Formulation of Iterative Eigenvalue Analysis Algorithm to the Second Order Newton Raphson Method (반복계산에 의한 고유치 해석 알고리즘의 2차 뉴튼랩슨법으로의 정식화)

  • Kim, Deok-Yeong
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.3
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    • pp.127-133
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    • 2002
  • This paper presents an efficient improvement of the iterative eigenvalue calculation method of the AESOPS algorithm. The intuitively and heuristically approximated iterative eigenvalue calculation method of the AESOPS algorithm is transformed to the Second Order Newton Raphson Method which is generally used in numerical analysis. The equations of second order partial differentiation of external torque, terminal and internal voltages are derived from the original AESOPS algorithm. Therefore only a few calculation steps are added to transform the intuitively and heuristically approximated AESOPS algorithm to the Second Order Newton Raphson Method, while the merits of original algorithm are still preserved.

Performance analysis of iterative groupwise equal-delay interference cancellation(IGEIC) for multiuser detection of coherent W-CDMA system (동기복조 W-CDMA 시스템의 다중 사용자 검출을 위한 반복 그룹단위 등지연 간섭제거(IGEIC) 알고리즘 성능해석)

  • 구제길;최형진
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.3B
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    • pp.179-187
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    • 2002
  • This paper proposes and analyzes the iterative groupwise equal-delay interference cancellation(IGEIC) algorithm for coherent detection of an asynchronous wideband DS-CDMA system in a single cell over multipath fading channels. The IGEIC algorithm divide users in a system into several groups, and subtract out interference signal from the received signal as many as the number of users within a user group, iteratively. The IGEIC algorithm is also classified into the iterative groupwise equal-delay serial interference cancellation(IGESIC) algorithm and the iterative groupwise equal-delay parallel interference cancellation(IGEPIC) algorithm. In the case of perfect correlation for spreading codes, it shows that the performance of IGESIC and IGEPIC algorithm is the same after interference cancellation of as many as the number of users within a user group, but the performance of IGEPIC algorithm is superior to the IGESIC algorithm just before fecal cancellation within a user group. The results show that (he performance of the two proposed algorithms are also superior to the SIC algorithm by 3dB.

Iterative Reliability-Based Modified Majority-Logic Decoding for Structured Binary LDPC Codes

  • Chen, Haiqiang;Luo, Lingshan;Sun, Youming;Li, Xiangcheng;Wan, Haibin;Luo, Liping;Qin, Tuanfa
    • Journal of Communications and Networks
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    • v.17 no.4
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    • pp.339-345
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    • 2015
  • In this paper, we present an iterative reliability-based modified majority-logic decoding algorithm for two classes of structured low-density parity-check codes. Different from the conventional modified one-step majority-logic decoding algorithms, we design a turbo-like iterative strategy to recover the performance degradation caused by the simply flipping operation. The main computational loads of the presented algorithm include only binary logic and integer operations, resulting in low decoding complexity. Furthermore, by introducing the iterative set, a very small proportion (less than 6%) of variable nodes are involved in the reliability updating process, which can further reduce the computational complexity. Simulation results show that, combined with the factor correction technique and a well-designed non-uniform quantization scheme, the presented algorithm can achieve a significant performance improvement and a fast decoding speed, even with very small quantization levels (3-4 bits resolution). The presented algorithm provides a candidate for trade-offs between performance and complexity.

An Iterative Normalization Algorithm for cDNA Microarray Medical Data Analysis

  • Kim, Yoonhee;Park, Woong-Yang;Kim, Ho
    • Genomics & Informatics
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    • v.2 no.2
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    • pp.92-98
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    • 2004
  • A cDNA microarray experiment is one of the most useful high-throughput experiments in medical informatics for monitoring gene expression levels. Statistical analysis with a cDNA microarray medical data requires a normalization procedure to reduce the systematic errors that are impossible to control by the experimental conditions. Despite the variety of normalization methods, this. paper suggests a more general and synthetic normalization algorithm with a control gene set based on previous studies of normalization. Iterative normalization method was used to select and include a new control gene set among the whole genes iteratively at every step of the normalization calculation initiated with the housekeeping genes. The objective of this iterative normalization was to maintain the pattern of the original data and to keep the gene expression levels stable. Spatial plots, M&A (ratio and average values of the intensity) plots and box plots showed a convergence to zero of the mean across all genes graphically after applying our iterative normalization. The practicability of the algorithm was demonstrated by applying our method to the data for the human photo aging study.

Iterative Unsharp Mask Filter for Digital Auto-Focusing (디지털 자동초점을 위한 반복적 Unsharp Mask 필터)

  • Shin, Jeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.5
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    • pp.145-152
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    • 2010
  • This paper presents a digital auto-focusing algorithm using iterative unsharp mask filter. The proposed digital auto-focusing algorithm has the advantage of low computational complexity because it uses a simple filter instead of calculating the point spread function for the estimation of image degradation. The proposed iterative algorithm can control the number of iterations for image restoration according to the objective and the subjective criterion. We show that the proposed algorithm is mathematically equivalent to the conventional image restoration. Finally, in order to evaluate the performance of the proposed algorithm, various experiments are performed so that the proposed algorithm can provide good results in the sense of subjective and objective views.

Parallel Algorithm of Improved FunkSVD Based on Spark

  • Yue, Xiaochen;Liu, Qicheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.5
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    • pp.1649-1665
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    • 2021
  • In view of the low accuracy of the traditional FunkSVD algorithm, and in order to improve the computational efficiency of the algorithm, this paper proposes a parallel algorithm of improved FunkSVD based on Spark (SP-FD). Using RMSProp algorithm to improve the traditional FunkSVD algorithm. The improved FunkSVD algorithm can not only solve the problem of decreased accuracy caused by iterative oscillations but also alleviate the impact of data sparseness on the accuracy of the algorithm, thereby achieving the effect of improving the accuracy of the algorithm. And using the Spark big data computing framework to realize the parallelization of the improved algorithm, to use RDD for iterative calculation, and to store calculation data in the iterative process in distributed memory to speed up the iteration. The Cartesian product operation in the improved FunkSVD algorithm is divided into blocks to realize parallel calculation, thereby improving the calculation speed of the algorithm. Experiments on three standard data sets in terms of accuracy, execution time, and speedup show that the SP-FD algorithm not only improves the recommendation accuracy, shortens the calculation interval compared to the traditional FunkSVD and several other algorithms but also shows good parallel performance in a cluster environment with multiple nodes. The analysis of experimental results shows that the SP-FD algorithm improves the accuracy and parallel computing capability of the algorithm, which is better than the traditional FunkSVD algorithm.

A Study on the Second-order Iterative Learning Control Algorithm with Feedback (궤환을 갖는 2차 반복 학습제어 알고리즘에 관한 연구)

  • Huh, Kyung-Moo
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.5
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    • pp.629-635
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    • 1999
  • A second-order iterative learning control algorithm with feedback is proposed in this paper, in which a feedback term is added in the learning control scheme for the enhancement of convergence speed and robustness to disturbances or system parameter variations. The convergence proof of the proposed algorithm is givenl, and the sufficient condition for the convergence of the algorithm is provided. And it also includes the discussions about the convergence performance of the algorithm when the initial condition at the beginning of each iteration differs from the previous value of the initial. Simulation results show the validity and efficiency of the proposed algorithm.

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