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10th International Symposium on Precision Engineering Measurements and Instrumentation (ISPEMI)

作者： Du, Hubing Yu, Jianhong Zhang, Shaofeng Xian Technol Univ Sch Mechatron Engn Xian 710032 Shaanxi Peoples R China

ISBN: (数字)9781510627826

ISBN: (纸本)9781510627826

The phase shifting shadow moire is an efficient technique for 3-D shape measurement. Our recent research focuses on improving its measurement accuracy without addition the complication of the experimental set-up. Considering that the existing measurement process of shifting shadow moire technique is complex, we had been looking for ways to make it easier. In this paper we propose some effective techniques to fulfil the aim. In the proposed method, the binocular stereovision technique is used to calibrate the geometric parameters of our setup. Then a method is developed to determine the grating translation difference. After that an iterative self-tuning algorithm is use to retrieve the accurate phase. The proposed method is fast and can be implemented easily in many applications. Optical experiments are implemented to verify the feasibility of this method.

关键词： iterative algorithm shadow moire phase-shifting

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Computational Efficiency Enhancements for Optimal Control Allocation

Computational Efficiency Enhancements for Optimal Control Al...

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AIAA Aviation Forum and Exposition

作者： Acheson, Michael J. NASA Langley Res Ctr Dynam Syst & Control Branch Hampton VA 23681 USA

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

Due to the ever increasing requirements of modern aircraft, the subject of control allocation continues to rise in importance. Modern aircraft control methodology requires control allocation algorithms that yield optimal (weighted) control solutions over the entire available envelope, readily accommodate changes in the number of available control effectors and do so in a numerically robust and computationally efficient manner that yields real-time solutions. Additionally, algorithms are being expanded to support dynamic control allocation topics such as linear stability analysis, control effector dynamics, enhance safety, prevent structural overload and address nonlinear control allocation challenges. Prior research has shown that weighted Pseudo-Inverse methods have been used successfully to address these requirements including nonlinear allocation (e.g., affine control effectiveness matrix). The Prediction Method was introduced as a weighted Pseudo-Inverse equivalent algorithm that typically provides optimal control allocation solutions within the envelope in a numerically robust manner. The research of this paper proposes computational efficiency enhancements to the core Prediction Method algorithm and the follow-on Sequential Null Space Generalized Inverse algorithm. These enhancements make use of partitioned matrices which substantially lowers the computational burden of matrix inversion and with the Scalar Difference Quadratic evaluation used for effector unsaturation detection. Numerical examples are presented and provide a computational efficiency comparison against the Cascading Generalized Inverse algorithm.

关键词： Optimal Control Thrust Vector Control High Alpha Research Vehicle MATLAB Ailerons iterative algorithm Computing Trailing Edge Flap Aircraft Control Angle of Attack

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Channel Estimation for Ambient Backscatter Communications with Large Intelligent Surface 11

Channel Estimation for Ambient Backscatter Communications wi...

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11th IEEE International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Zheng, Hui Yang, Ziyao Wang, Gongpu He, Ruisi Ai, Bo Beijing Jiaotong Univ Beijing Key Lab Transportat Data Anal & Min Beijing Peoples R China Beijing Jiaotong Univ State Key Lab Rail Traff Control & Safety Beijing Peoples R China

ISBN: (纸本)9781728135557

In this paper, we investigate the channel estimation problem for ambient backscatter communication system where the backscatter device utilizes large intelligent surface (LIS). For the considered LIS-assisted system, a general system model for ambient backscatter with LIS features is presented. Based on the general mathematical framework we proposed, we design an estimator consisting of initial estimation and subsequent iteration to acquire the channel parameters. To further evaluate the performance of the suggested estimator, we derive the corresponding Cramer-Rao lower bounds (CRLBs) for channel estimates. Simulation results are then provided to corroborate the proposed studies.

关键词： Ambient backscatter channel estimation large intelligent surface (LIS) least-square method (LS) iterative algorithm Cramer-Rao lower bound (CRLB)

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An iterative algorithm for Optimal Carrier Sensing Threshold in Random CSMA/CA Wireless Networks

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IEEE COMMUNICATIONS LETTERS 2013年第11期17卷 2076-2079页

作者： Kim, Dong Min Kim, Seong-Lyun Yonsei Univ Sch Elect & Elect Engn Radio Resource Management & Optimizat Lab Seoul 120749 South Korea

We investigate the optimal carrier sensing threshold in random CSMA/CA networks considering the effect of binary exponential backoff. We propose an iterative algorithm for optimizing the carrier sensing threshold and hence maximizing the area spectral efficiency. We verify that simulations are consistent with our analytical results.

关键词： CSMA/CA carrier sensing threshold iterative algorithm stochastic geometry

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MINIMAX MAGNITUDE RESPONSE APPROXIMATION OF POLE-RADIUS CONSTRAINED IIR DIGITAL FILTERS 44

MINIMAX MAGNITUDE RESPONSE APPROXIMATION OF POLE-RADIUS CONS...

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44th IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

作者： Lai, Xiaoping Cao, Jiuwen Lin, Zhiping Hangzhou Dianzi Univ Inst Informat & Control Hangzhou Zhejiang Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore Singapore

ISBN: (纸本)9781479981311

Design of infinite impulse response (IIR) digital filters to approximate some desired magnitude-frequency response is a classical research topic in signal processing. When a pole radius constraint is imposed, however, the problem becomes challenging and few solution methods are available. This paper converts the magnitude-response approximation problem into another problem that approximates the desired magnitude response and an accompanied phase response simultaneously. By iteratively updating the accompanied phase response. a solution to the original magnitude-response approximation problem can be obtained. A striking feature of the proposed method is that the pole radius constraint can be easily incorporated in the problem. Simulations and comparisons demonstrate the effectiveness of the method.

关键词： IIR digital filter approximation problem magnitude response pole radius iterative algorithm

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Research on Saturated Spatial Power Load Forecasting Based on Land Utility 2019

Research on Saturated Spatial Power Load Forecasting Based o...

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Proceedings of the 2nd International Conference on Information Technologies and Electrical Engineering

作者： Qi Han Renhai Feng Wanqi Yuan Chuanjun Shao Electric Power Research Institute State Grid Shandong Electric Power Co. Ltd JiNan China School of EIE Tianjin University Tianjin China

ISBN: (纸本)9781450372930

With the increasing demand for electricity, accurate prediction of power load is of great significance for improving the quality of power grid planning and construction. Traditional saturated load forecasting method is greatly affected by historical information. This paper proposed an improved spatial load forecasting(SLF) method based on error model transformation. Considering the nature and development time of urban land, each district is divided into different blocks, the blocks are classified into two categories: homogeneous blocks and simultaneous blocks. An iterative load forecasting system architecture is proposed, which transforms blocks load forecasting problem into two sub-problems: multi-level gridding parameter training and model integrative prediction. Land utility and historical data are both investigated during the load forecasting procedure. Simulation result indicates that accuracy of calculated prediction result is higher and less affected by the noise.

关键词： distribution network iterative algorithm maximum likelihood estimation error model transformation load forecasting

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iterative algorithm of solutions for a system of generalized mixed implicity equilibrium problems in reflexive Banach spaces

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APPLIED MATHEMATICS AND COMPUTATION 2012年第9期218卷 4953-4961页

作者： Ding, Xie Ping Sichuan Normal Univ Coll Math & Software Sci Chengdu 610066 Sichuan Peoples R China

In this paper, a new system of generalized mixed implicity equilibrium problems involving non-monotone set-valued mappings is introduced and studied in real reflexive Banach spaces. Following the idea of Moudafi, we consider a system of generalized equations problems and show its equivalence with the system of generalized mixed implicity equilibrium problems. By using a fixed point formulation of the system of generalized equation problems, a new iterative algorithm for solving the system of generalized mixed implicity equilibrium problems is suggested and analyzed. The strong convergence of the iterative sequences generated by the algorithm is proved under suitable conditions. These results are new and unify and generalize some recent results in this field. (C) 2011 Elsevier Inc. All rights reserved.

关键词： System of generalized mixed implicity equilibrium problems System of generalized equation problems iterative algorithm Reflexive Banach spaces

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On iterative Solutions of Periodic Sylvester Matrix Equations

On Iterative Solutions of Periodic Sylvester Matrix Equation...

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第三十九届中国控制会议

作者： Zebin Chen Xuesong Chen School of Applied Mathematics Guangdong University of Technology

We propose a gradient based iterative algorithm with multiple iterative factors(MGI) to find the solutions of the Sylvester discrete-time periodic matrix equations Aj Xj + Xj+1 Bj = Cj(j = 1, 2, ···, T). It is proved that the exact solution of the periodic matrix equations can be converged by the MGI method for any initial matrices. Then, we study the optimal convergence rate of gradient based iterative algorithm with single iterative factor(SGI). Nextly, we compare the convergence rate of the two algorithms, and find that MGI is faster than SGI when the appropriate convergence factors μj are selected. Finally, a numerical example is given to verify that MGI is superior to SGI in both speed and iterative steps.

关键词： iterative algorithm Multiple iterative Factors Periodic Matrix Equations Convergence Rate

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Enhancement of vibration desensitising capability of iterative algorithms for phase-shifting interferometers

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OPTICS AND LASERS IN ENGINEERING 2017年第Nov.期98卷 31-36页

作者： Liu, Qian Yuan, Daocheng He, Huabin China Acad Engn Phys Inst Machinery Mfg Technol 64th Mianshan Rd Mianyang 621000 Sichuan Peoples R China Xi An Jiao Tong Univ Sch Mech Engn 28 Xianning West Rd Xian 710049 Shaanxi Peoples R China

The sensitivity of phase-shifting interferometers (PSIs) to vibration impairs their application in unsteady environment. iterative algorithms were developed to desensitise the effect of vibration on PSIs, but their desensitising capability is restricted by the estimated initial value. In this paper, a spatial carrier-assisted method is proposed, in which a wavefront phase retrieved from an additional spatial-carrier interferogram is used as the initial value. Because of the benefits of spatial carrier, vibration immunity and sign determination, iteration could converge to accurate value even when interferometers are under severe vibration. To reduce the possibility of transverse movement of the measured surface, subsampling strategy is further proposed to decrease the required tilt angle, with the additional benefit of decreasing the calculation time of iteration. Computer simulations and experiments are performed to verify the effectiveness of the proposed method. Results indicate that the vibration desensitising capability of an iterative algorithm is significantly enhanced by the proposed method. The proposed method improves the vibration desensitising capability with low cost and is thus highly compatible. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Metrology Phase-shifting interferometry iterative algorithm Vibration desensitisation

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SELF-ADAPTIVE iterative algorithmS FOR SOLVING MULTIPLE-SET SPLIT EQUALITY COMMON FIXED-POINT PROBLEMS OF DEMICONTRACTIVE OPERATORS

JOURNAL OF NONLINEAR FUNCTIONAL ANALYSIS

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JOURNAL OF NONLINEAR FUNCTIONAL ANALYSIS 2018年 2018卷

作者： Su, Hongyan Zhao, Jing Qingdao Univ Sci & Technol Dept Math Qingdao 266000 Peoples R China Civil Aviat Univ China Coll Sci Tianjin 300300 Peoples R China

In this paper, we introduce parallel and cyclic iterative algorithms for solving the multiple-set split equality common fixed-point problem of demicontractive operators. We propose a way of selecting the stepsizes such that the implementation of our algorithms does not need any prior information about operator norms. It thus avoids the difficult task of estimating the operator norms. We also combine the process of cyclic and parallel together and propose two mixed iterative algorithms without prior knowledge of operator norms. The weak convergence theorems of the proposed algorithms are established under some suitable control conditions in a real Hilbert space. Some numerical experiments are given for the proposed iterative algorithms.

关键词： Multiple-set split equality common fixed-point problem Demicontractive operator Weak convergence iterative algorithm Hilbert space

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