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Sensing Matrix optimization for Random Stepped-Frequency Signal Based on Two-Dimensional Ambiguity Function

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Chinese Journal of Electronics 2024年第1期33卷 161-174页

作者： Mingjiu LYU Hao CHEN Jun YANG Xia WU Ming ZHOU Xiaoyan MA Radar NCO School Air Force Early Warning Academy Department of Early Warning Technology Air Force Early Warning Academy

Compressive sensing technique has been widely applied to achieve range-Doppler reconstruction of high frequency radar by utilizing sparse random stepped-frequency(SRSF) signal, which can suppress the complex electromagnetic interference and greatly reduce the coherent processing interval. An important way to improve the performance of sparse signal reconstruction is to optimize the sensing matrix(SM). However, the existing research on the SM optimization needs to design a measurement matrix with superior performance, which needs a large amount of computation and does not consider the influence of the waveform parameters design. In order to improve the superior reconstruction performance, a novel SM optimization approach for SRSF signal is proposed by using two-dimensional ambiguity function(TDAF) in this paper. Firstly, based on the two-dimensional sparse reconstruction model of the SRSFs, the internal relationship between the waveform parameters and the SM was derived. Secondly, the SM optimization problem was directly transformed into the waveform design of SRSFs. Furthermore, on the basis of analyzing the relationship between the mutual coherence matrix of SM and the TDAF matrix of SRSFs, the purpose of optimizing the SM can be achieved by designing the TDAF of the SRSFs. Based on this analysis, a sparse waveform optimization method with joint constraints of maximum and mean sidelobes of the TDAF by using the genetic algorithm was derived. Compared with the traditional SM optimization method, our method not only avoids generating a new measurement matrix, but also further reduces the complexity of the waveform optimization. Simulation experiments verified the effectiveness of the proposed method.

关键词： Correlation Computational modeling Electromagnetic interference optimization methods Signal reconstruction High frequency radar Sensors

Factor graph based navigation and positioning for control system design:A review

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Chinese Journal of Aeronautics 2022年第5期35卷 25-39页

作者： Xiwei WU Bing XIAO Cihang WU Yiming GUO Lingwei LI School of Automation Northwestern Polytechnical UniversityXi’an 710072China

Navigation and positioning is an important and challenging problem in many control engineering *** provides feedback information to design controllers for *** this paper,a bibliographical review on factor graph based navigation and positioning is *** specifically,the sensor modeling,the factor graph optimization methods,and the topology factor based cooperative localization are *** navigation and positioning methods via factor graph are considered and *** in the current research of factor graph based navigation and positioning are also discussed with emphasis on its practical *** limitations of the existing methods,some solutions for future techniques,and recommendations are finally given.

关键词： Factor graph Navigation optimization methods Positioning Sensor modeling

Predictive Control Based on Ranking Multi-objective optimization Approaches for a quasi-Z Source Inverter

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CSEE Journal of Power and Energy Systems 2021年第6期7卷 1152-1160页

作者： Abualkasim Bakeer Gaber Magdy Andrii Chub Dmitri Vinnikov the Department of Electrical Engineering Faculty of EngineeringAswan University81542 AswanEgypt the Power Electronics Group Department of Electrical Power Engineering and MechatronicsTallinn University of TechnologyTallinn 19086Estonia the Department of Electrical Engineering Faculty of Energy EngineeringAswan University81542 AswanEgypt

In power converter control,predictive control has several merits,such as simple concept and fast ***,the necessity to use the weighting factor inside the cost function makes the control design complex in the case of regulating multivariables where the value of the weighting factor is obtained by a nontrivial ***,it primarily depends on the system parameters and operating points of the control *** paper aims to enhance the model predictive algorithm of the singlestage topology of a quasi-Z Source Inverter(qZSI).The concept of a multi-objective optimization approach is used in addition to the sub-cost function definition to remove the weighting *** using the sub-cost function definition,the inductor current is pushed away from the main loop of the predictive ***,no weighting factor is needed to manage the priority of the inductor *** other two control targets,which are the capacitor voltage and load currents,will be controlled by the multi-objective optimization approach without using any weighting factors.A detailed theoretical analysis of the proposed technique will be given and validated based on simulation results.

关键词： Cost function definition model predictive control optimization methods quasi-Z Source Inverter(qZSI) weighting factors

Sequential ensemble optimization based on general surrogate model prediction variance and its application on engine acceleration schedule design

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Chinese Journal of Aeronautics 2021年第8期34卷 16-33页

作者： Yifan YE Zhanxue WANG Xiaobo ZHANG Shannxi Key Laboratory of Internal Aerodynamic in Aero-Engine School of Power and EnergyNorthwestern Polytechnical UniversityXi'an 710072China

The Efficient Global optimization(EGO)algorithm has been widely used in the numerical design optimization of engineering ***,the need for an uncertainty estimator limits the selection of a surrogate *** this paper,a Sequential Ensemble optimization(SEO)algorithm based on the ensemble model is *** the proposed algorithm,there is no limitation on the selection of an individual surrogate ***,the SEO is built based on the EGO by extending the EGO algorithm so that it can be used in combination with the ensemble ***,a new uncertainty estimator for any surrogate model named the General Uncertainty Estimator(GUE)is *** performance of the proposed SEO algorithm is verified by the simulations using ten well-known mathematical functions with varying *** results show that the proposed SEO algorithm performs better than the traditional EGO algorithm in terms of both the final optimization results and the convergence ***,the proposed algorithm is applied to the global optimization control for turbo-fan engine acceleration schedule design.

关键词： Cross-validation Efficient global optimization Engine acceleration schedule design Ensemble of surrogate models Gas turbine engine optimization methods Surrogate-based optimization

A D-optimal Multi-position Calibration Method for Dynamically Tuned Gyroscopes

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Chinese Journal of Aeronautics 2011年第2期24卷 210-218页

作者： FU Li ZHU Yongquan WANG Lingling WANG Xinling School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China

This paper presents a novel experimental design to greatly improve the calibration accuracy of the acceleration-insensitive bias and the acceleration-sensitive bias of the dynamically tuned gyroscopes（DTGs）.In order to reduce experimental cost,the D-optimal criteria with constraints are *** turntable positions and the number of test points are chosen to build D-optimal experimental *** D-optimal experimental designs are tested by multi-position calibration experiment for tactical-grade *** results show that,with the same cost,the fit uncertainty is reduced by about 50% by using the D-optimal 8-position experimental procedure,compared to using a defacto standard experimental procedure in ANSI/IEEE Std ***,the new experimental procedure almost achieves optimal accuracy with only 12-position which is half the cost of the widely adopted 24-position experimental procedure for achieving optimal accuracy.

关键词： optimization methods calibration gyroscopes error compensation design for testability

An iterative re-weighted least-squares algorithm for the design of active absorbing wavemaker controller

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Journal of Hydrodynamics 2016年第2期28卷 206-218页

作者：杨洪齐李木国柳淑学陈芳梅 State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology The Department of Electronic Engineering Tsinghua University

In physical model tests for highly reflective structures, one often encounters a problem of multiple reflections between the reflective structures and the wavemaker. Absorbing wavemakers can cancel the re-reflective waves by adjusting the paddle motion. In this paper, we propose a method to design the controller of the 2-D absorbing wavemaker system in the wave flume. Based on the first-order wavemaker theory, a frequency domain absorption transfer function is derived. Its time realization can be obtained by de- signing an infinite impulse response （IIR） digital filter, which is expected to approximate the absorption transfer function in the least- squares sense. A commonly used approach to determine the parameters of the IIR filter is applying the Taylor expansion to linearize the filter formulation and solving the linear least-squares problem. However, the result is not optimal because the linearization cha- nges the original objective function. To improve the approximation performance, we propose an iterative reweighted least-squares （IRLS） algorithm and demonstrate that with the filters designed by this algorithm, the approximation errors can be reduced. Physical experiments are carried out with the designed controller. The results show that the system performs well for both regular and irregu- lar waves.

关键词： wavemaker active absorption infinite impulse response (IIR) digital filters optimization methods

Review of cylinder block/valve plate interface in axial piston pumps: Theoretical models,experimental investigations, and optimal design

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Chinese Journal of Aeronautics 2021年第1期34卷 111-134页

作者： Jiang'ao ZHAO Yongling FU Jiming MA Jian FU Qun CHAO Yan WANG School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Laboratory of Aerospace Servo Actuation and Transmission Beihang UniversityBeijing 100191China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

Axial piston pumps have been widely used in aircraft hydraulic systems to supply the system with pressurized fluid. The continuous improvement of the aircraft performance has put forward the demand on aviation piston pumps for high power density, safety, and reliability. The lubricating interfaces in axial piston machines are the key design issue that greatly determines the pump performance and service life. The cylinder block/valve plate interface is one of these critical lubricating interfaces and has received considerable attention from many researchers in the last half century. This study aims to review the state-of-the-art literature on the cylinder block/valve plate interface comprehensively and systematically. First, we introduce various theoretical models developed to investigate the lubrication behaviors of the interface and compare them in terms of their assumptions and limitations. Second, the experimental studies on the cylinder block/valve plate interface are presented comprehensively, where the involved test rigs are divided into three types according to their fidelity levels and measurement functionality. Third, we summarize some typical approaches of structure optimization, surface shaping, and surface strengthening, which help improve the load-carrying and anti-wear capacities of the interface under severe operating conditions. Finally, the challenges and future trends of the cylinder block/valve plate interface research are discussed briefly.

关键词： Axial piston pump Cylinder block/valve plate interface Theoretical model Test rig optimization methods

Phishing Websites Detection by Using Optimized Stacking Ensemble Model

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Computer Systems Science & Engineering 2022年第4期41卷 109-125页

作者： Zeyad Ghaleb Al-Mekhlafi Badiea Abdulkarem Mohammed Mohammed Al-Sarem Faisal Saeed Tawfik Al-Hadhrami Mohammad T.Alshammari Abdulrahman Alreshidi Talal Sarheed Alshammari College of Computer Science and Engineering University of Ha'ilHa'il81481KSA College of Computer Sciences and Engineering Hodeidah UniversityHodeidah967Yemen College of Computer Science and Engineering Taibah UniversityAl-Madinah42353KSA Nottingham Trent University MansfieldNG185BHUnited Kingdom

Phishing attacks are security attacks that do not affect only individuals’or organizations’websites but may affect Internet of Things(IoT)devices and *** environment is an exposed environment for such *** may use thingbots software for the dispersal of hidden junk emails that are not noticed by *** and deep learning and other methods were used to design detection methods for these ***,there is still a need to enhance detection *** of an ensemble classiﬁcation method for phishing website(PW)detection is proposed in this study.A Genetic Algo-rithm(GA)was used for the proposed method optimization by tuning several ensemble Machine Learning(ML)methods parameters,including Random Forest(RF),AdaBoost(AB),XGBoost(XGB),Bagging(BA),GradientBoost(GB),and LightGBM(LGBM).These were accomplished by ranking the optimized classi-ﬁers to pick out the best classiﬁers as a base for the proposed method.A PW data-set that is made up of 4898 PWs and 6157 legitimate websites(LWs)was used for this study's *** a result,detection accuracy was enhanced and reached 97.16 percent.

关键词： Phishing websites ensemble classiﬁers optimization methods genetic algorithm

The incremental subgradient methods on distributed estimations in-network

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Science China(Information Sciences) 2014年第9期57卷 30-39页

作者： FENG Hui JIANG ZiDong HU Bo ZHANG JianQiu Department of Electronic Engineering Fudan University

A unified framework on distributed estimations in-network using incremental subgradient(IS)methods is *** IS methods meet the requirement of the asynchronously processing,which are efficient solvers developed recently focusing on separable non-differentiable convex optimization *** main contribution of this paper is to formalize distributed estimators as equivalent separable convex optimization problems,where general skills and several specific cases on signal estimations are *** and simulation results show that the IS framework can solve general nonlinear estimation problems in-network,and achieve comparable performances as the centralized estimators.

关键词： distributed signal processing signal processing in-network distributed estimation incremental subgradient optimization methods