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Structured-Chromosome Evolutionary algorithms for Variable-Size Autonomous Interplanetary Trajectory Planning Optimization

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JOURNAL OF AEROSPACE INFORMATION SYSTEMS 2015年第3期12卷 314-328页

作者： Nyew, Hui Meen Abdelkhalik, Ossama Onder, Nilufer Michigan Technol Univ Dept Comp Sci Houghton MI 49931 USA Michigan Technol Univ Dept Mech Engn Engn Mech Houghton MI 49931 USA

In interplanetary trajectory optimization, events such as planetary gravitational-assist maneuvers (swingbys) and deep-space maneuvers can be added/removed from the trajectory plan to reduce the cost or the flight time. This renders the number of design variables in the optimization problem variable. Global optimization methods that optimize this type of multimodal objective function can only handle problems with a fixed number of design variables. This paper presents the structured-chromosome evolutionary algorithm framework that is developed to handle variable-size design space optimization problems. In this framework, a solution (chromosome) is represented by a hierarchical data structure where the genes in the chromosome are classified as dependent and nondependent genes. This structure provides the capability to apply genetic operations between solutions of different lengths, and thus to automatically determine the number of swingbys, the planets to swingby, launch and arrival dates, and the number of deep-space maneuvers, as well as their locations, magnitudes, and directions, in an optimal sense. This new method is applied to several interplanetary trajectory design problems. Results show that solutions obtained using this tool match known solutions for some complex problems. A comparison between genetic algorithms and differential evolution in the structured-chromosome framework is presented.

关键词： Interplanetary Trajectories Structured Chromosome Evolutionary algorithms Saturn Optimal Impulsive Maneuvers Hidden Genes Genetic algorithms iterative algorithm Jupiter Europa Orbiter Trajectory Optimization Nonlinear Programming Statistical Analysis

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Split general strong nonlinear quasi-variational inequality problem

Split general strong nonlinear quasi-variational inequality ...

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2016 2nd International Conference on Electronics,Network and Computer Engineering(ICENCE 2016)

作者： Dongxue Han Yali Zhao College of Mathematics and Physics Bohai University

In this paper, we introduce a split general strong nonlinear quasi-variational inequality problem which is a natural extension of a split general quasi-variational inequality problem, split variational inequality problem, quasi-variational and variational inequality problems in Hilbert spaces. Using the projection method, we propose an iterative algorithm for the split general strongly nonlinear quasi-variational inequality problem and discuss the convergence criteria of the iterative *** results presented here generalized, unify and improve many previously known results for quasi-variational and variational inequality problems.

关键词： Split general strongly nonlinear quasi-variational inequality problem split general quasi-variational inequality problem iterative algorithm convergence

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iterative Vessel Segmentation of Fundus Images

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IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 2015年第7期62卷 1738-1749页

作者： Roychowdhury, Sohini Koozekanani, Dara D. Parhi, Keshab K. Univ Washington Dept Elect & Comp Engn Bothell WA 98011 USA Univ Minnesota Dept Ophthalmol Minneapolis MN 55455 USA Univ Minnesota Dept Elect & Comp Engn Minneapolis MN 55455 USA

This paper presents a novel unsupervised iterative blood vessel segmentation algorithm using fundus images. First, a vessel enhanced image is generated by tophat reconstruction of the negative green plane image. An initial estimate of the segmented vasculature is extracted by global thresholding the vessel enhanced image. Next, new vessel pixels are identified iteratively by adaptive thresholding of the residual image generated by masking out the existing segmented vessel estimate from the vessel enhanced image. The new vessel pixels are, then, region grown into the existing vessel, thereby resulting in an iterative enhancement of the segmented vessel structure. As the iterations progress, the number of false edge pixels identified as new vessel pixels increases compared to the number of actual vessel pixels. A key contribution of this paper is a novel stopping criterion that terminates the iterative process leading to higher vessel segmentation accuracy. This iterative algorithm is robust to the rate of new vessel pixel addition since it achieves 93.2-95.35% vessel segmentation accuracy with 0.9577-0.9638 area under ROC curve (AUC) on abnormal retinal images from the STARE dataset. The proposed algorithm is computationally efficient and consistent in vessel segmentation performance for retinal images with variations due to pathology, uneven illumination, pigmentation, and fields of view since it achieves a vessel segmentation accuracy of about 95% in an average time of 2.45, 3.95, and 8 s on images from three public datasets DRIVE, STARE, and CHASE_DB1, respectively. Additionally, the proposed algorithm has more than 90% segmentation accuracy for segmenting peripapillary blood vessels in the images from the DRIVE and CHASE_DB1 datasets.

关键词： Accuracy computational complexity fundus image iterative algorithm morphological reconstruction stopping criterion vessel segmentation

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A Finite iterative Method for Solving the General Coupled Discrete-Time Periodic Matrix Equations

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2015年第1期34卷 105-125页

作者： Hajarian, Masoud Shahid Beheshti Univ Fac Math Sci Dept Math Tehran 19839 Iran

Analysis and design of linear periodic control systems are closely related to the discrete-time periodic matrix equations. In this paper, we propose an iterative algorithm based on the conjugate gradient method on the normal equations (CGNE) for finding the solution group of the general coupled periodic matrix equations {A(1), (i) X-i B-1,B- i + C-1,C- i Xi+1D1, i = E-1,E- i, A(2, i) X-i B-2,B- i + C-2,C- i Xi+1D2, i = E-2,E- i, for i = 1, 2, 3, ... By proving some properties of the algorithm, we show that the solution group of the periodic matrix equations can be obtained within a finite number of iterations in the absence of roundoff errors. Numerical examples are given to illustrate the efficiency and accuracy of the proposed algorithm.

关键词： Discrete-time periodic matrix equation iterative algorithm Conjugate gradient method

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Fast Computation of Discrete Optimal FIR Estimates in White Gaussian Noise

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IEEE SIGNAL PROCESSING LETTERS 2015年第6期22卷 718-722页

作者： Zhao, Shunyi Shmaliy, Yuriy S. Liu, Fei Jiangnan Univ Key Lab Adv Proc Control Light Ind Minist Educ Wuxi Peoples R China Univ Guanajuato Dept Elect Engn Salamanca 36885 Mexico

We propose a fast iterative algorithm for optimal finite impulse response (OFIR) filtering of linear discrete time-invariant state-space models in white Gaussian noise. The OFIR filter is known to have the BIBO stability and better robustness against the Kalman filter (KF). The iterative OFIR algorithm is KF-like;that is, its estimate appears much faster than in the batch OFIR filter. A dramatic reduction of computation time is demonstrated in the full-horizon iterative OFIR algorithm which operates as fast as KF. We also notice a considerable reduction of the computational resources allowed by iterations.

关键词： iterative algorithm optimal FIR filtering state space white Gaussian noise

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An Efficiency Maximization Design for SWIPT

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IEEE SIGNAL PROCESSING LETTERS 2015年第12期22卷 2189-2193页

作者： Quang-Doanh Vu Le-Nam Tran Farrell, Ronan Hong, Een-Kee Kyung Hee Univ Sch Elect & Informat Yongin 449701 South Korea Maynooth Univ Dept Elect Engn Maynooth Kildare Ireland

A joint power splitting and beamforming design for multiuser multiple-input single-output (MISO) systems where receivers have capability of decoding information and harvesting energy simultaneously from received signals is considered. The objective is to maximize the ratio of the achieved utility to the total power consumption subject to harvested power requirements and power budget at a base station (BS). The utility function of interest combines the sum rate and the total harvested power. The design problem is nonconvex, and thus, global optimality is difficult to achieve. To solve this problem locally we first convert the problem into a more tractable form, and then propose an iterative algorithm which is guaranteed to achieve a Karush-Kuhn-Tucker solution. Numerical results are provided to demonstrate the superior performance of the proposed method.

关键词： Energy harvesting fractional problem iterative algorithm linear precoding power splitting

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Simulation Study on iterative Reconstruction Method for Time-Correlation Magnetic Particle Imaging With Continuous Trajectory Scan

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IEEE TRANSACTIONS ON MAGNETICS 2015年第2期51卷 6501004-1-6501004-4页

作者： Shimizu, Shota Homma, Takumi Tsuchiya, Hiroki Ishihara, Yasutoshi Meiji Univ Grad Sch Sci & Technol Kawasaki Kanagawa 2148571 Japan Meiji Univ Sch Sci & Technol Kawasaki Kanagawa 2148571 Japan

Magnetic particle imaging (MPI) is a medical imaging technology suitable for noninvasive diagnostics. However, in conventional image reconstruction methods, due to either noise or the reconstruction method itself, the reconstructed image quality degrades. In order to suppress this problem, we improved the time-correlation MPI method that we had previously proposed. Specifically, this method iteratively corrects image blurring by reducing the difference between the observed signals from magnetic nanoparticles and the analytically calculated waveforms for the reconstructed image generated with the time-correlation method. Using numerical simulation, we evaluate the effectiveness of this method in conjunction with the continuous scan technique, which makes fast data acquisition possible.

关键词： Image reconstruction iterative algorithm magnetic particle imaging (MPI) molecular imaging

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New iterative algorithm for solving a third-order one-dimensional nonlinear pseudoparabolic equation

New iterative algorithm for solving a third-order one-dimens...

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2011 International Conference on Computers, Communications, Control and Automation

作者： Shiping Zhou Wei Feng School of Computer and Technology Yantai University

In this paper, we develop an itarative algorithm to solve for a one-dimensional nonlinear pseudoparabolic equation in the reproducing space. It is proved that the approximate sequence μ_n（x, t） converges to the exa... 详细信息

关键词： iterative algorithm Nonlinear pseudoparabolic equation Reproducing kernel space Nonlocal boundary condition

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Graph Convergence for the H(.,.)-Co-accretive Mapping with an Application

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BULLETIN OF THE MALAYSIAN MATHEMATICAL SCIENCES SOCIETY 2015年第4期38卷 1481-1506页

作者： Ahmad, R. Akram, M. Dilshad, M. Aligarh Muslim Univ Dept Math Aligarh 202002 Uttar Pradesh India Islamic Univ Madinah Fac Sci Dept Math Madinah Saudi Arabia Univ Tabuk Dept Math Tabuk 71491 Saudi Arabia

In this paper, we introduce a concept of graph convergence for the H(., .)-co-accretive mapping in Banach spaces and prove an equivalence theorem between graph convergence and resolvent operator convergence for the H(., .)-co-accretive mapping. Further, we consider a system of generalized variational inclusions involving H(., .)-co-accretive mapping in real q-uniformly smooth Banach spaces. Using resolvent operator technique, we prove the existence and uniqueness of solution and suggest an iterative algorithm for the system of generalized variational inclusions under some suitable conditions. Further, we discuss the convergence of iterative algorithm using the concept of graph convergence. Our results can be viewed as a refinement and generalization of some known results in the literature.

关键词： Graph convergence H(.,.)-co-accretive mapping iterative algorithm System of generalized variational inclusions Convergence criteria

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Decoupling capacitors selection algorithm based on maximum anti-resonance points and quality factor of capacitor

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ELECTRONICS LETTERS 2015年第1期51卷 90-U107页

作者： Liu, Yang Yuan, Yu-Zhang Chen, Kong-Qian Chen, Wei-Wei Xidian Univ Inst Elect CAD Xian 710071 Peoples R China

A decoupling capacitors (decaps) selection algorithm based on maximum anti-resonance points of the power distribution network and the quality factor (Q) of the capacitor is proposed. The experimental results show that the proposed algorithm is superior to the fast algorithm regarding the number of consuming decaps and the genetic algorithm regarding the time consumed.

关键词： terahertz wave imaging quantum cascade lasers quantum well devices photodetectors computerised tomography image reconstruction iterative methods three-dimensional imaging terahertz quantum cascade laser quantum well photodetector three-dimensional terahertz computed tomography system receiver algebraic reconstruction technique image reconstruction iterative algorithm beam hardening effect

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