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Delay-dependent robust H_∞control of convex polyhedral uncertain fuzzy systems

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Journal of Systems Engineering and Electronics 2008年第6期19卷 1191-1198页

作者： gong Cheng Su Baoku Dept. of Control Theory and Control Engeering Harbin Inst. of Technology Harbin 150001 P. R. China

The robust H∞ control problem for a class of uncertain Takagi-Sugeno fuzzy systems with timevarying state delays is studied. The uncertain parameters are supposed to reside in a polytope. Based on the delay-dependent Lyapunov functional method, a new delay-dependent robust H∞ fuzzy controller, which depends on the size of the delays and the derivative of the delays, is presented in term of linear matrix inequalities （LMIs）. For all admissible uncertainties and delays, the controller guarantees not only the asymptotic stability of the system but also the prescribed H∞ attenuation level. In addition, the effectiveness of the proposed design method is demonstrated by a numerical example.

关键词： robust H∞ control delay-dependent polyhedral uncertainty fuzzy systems

Bus holding strategy based on shuffled complex evolution method

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Frontiers of Computer Science 2012年第4期6卷 462-468页

作者： Yu JIANG Shuli gong College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Holding strategies are among the most commonly used operation control strategies. This paper presents an improved holding strategy. In the strategy, a mathematical model aiming to minimize the total waiting times of pas- sengers at the current stop and at the following stops is con- structed and a new heuristic algorithm, shuffled complex evo- lution method developed at the University of Arizona （SCE- UA）, is adopted to optimize the holding times of early buses. Results show that the improved holding strategy can provide better performance compared with a traditional schedule- based holding strategy and no-control strategy. The compu- tational results are also evidence of the feasibility of using SCE-UA in optimizing the holding times of early buses at a stop.

关键词： public transportation improved holding strategy schedule heuristic algorithm-shuffled complex evolution

Horn–Schunck optical flow applied to deformation measurement of a birdlike airfoil

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Chinese Journal of Aeronautics 2015年第5期28卷 1305-1315页

作者： gong Xiaoliang Stephan Bansmer School of Aeronautics Northwestern Polytechnical University Institute of Fluid Mechanics Technische Universitt Braunschweig

Current deformation measurement techniques suffer from limited spatial resolution. In this work, a highly accurate and high-resolution Horn Schunck optical flow method is developed and then applied to measuring the static deformation of a birdlike flexible airfoil at a series of angles of attack at Reynolds number 100,000 in a low speed, low noise wind tunnel. To allow relatively large displacements, a nonlinear Horn-Schunck model and a coarse-to-fine warping process are adopted. To preserve optical flow discontinuities, a nonquadratic penalization function, a multi- cue driven bilateral filtering and a principle component analysis of local image patterns are used. First, the accuracy and convergence of this Horn-Schunck technique are verified on a benchmark. Then, the maximum displacement that can be reliably calculated by this technique is studied on synthetic images. Both studies are compared with the performance of a Lucas-Kanade optical flow method. Finally, the Horn-Schunck technique is used to estimate the 3-D deformation of the birdlike airfoil through a stereoscopic camera setup. The results are compared with those computed by Lucas-Kanade optical flow, image correlation and numerical simulation.

关键词： Deformation measurementsFlexible airfoil Horn-Schunck Optical flow Stereoscopic

On Optimal Priority Modelling of Group Intuitionistic Fuzzy Preference Relations with Normal Uncertainty Distribution

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Journal of Systems Science and Systems Engineering 2019年第4期28卷 510-525页

作者： Lihong Wang Zaiwu gong College of Management Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044 China

The uncertainty distribution can more effectively express the uncertainty of decision makers' judgments during a pairwise comparison of any alternatives. This paper investigates the priority models of group intuitionistic fuzzy preference relations with normal uncertainty distribution. The mathematical equivalence between the membership, non-membership degree interval fuzzy preference relation and the intuitionistic fuzzy preference relation is constructed, showing that there exists an inverse relationship between the priority of alternatives using these two types of interval preference relations. The new optimal models regarded the event that the deviation between the ideal judgement meeting the multiplicative consistency and the actual judgement obeying normal uncertainty distribution shall not exceed a threshold value under the given belief degree as a constraint, and regarded the minimum sum of all the threshold values as the objective function. The chance constraint was introduced to measure the degree to which multiplicative consistency can be realized under different belief degrees. The priority model provides a new method for simulating uncertainty and fuzziness in the real-world decision making environment.

关键词： Group decisions and negotiations intuitionistic fuzzy preference relation multiplicative consistency normal uncertainty distribution chance constraint programming

Safety Analysis of Flow Parameters in a Rotor-stator Cavity

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Chinese Journal of Aeronautics 2012年第6期25卷 831-838页

作者： ZHANG gong DING Shuiting Airworthiness Technologies Research Center Beihang University Beijing 100191 China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Jet Propulsion Bei hang University Beij ing 100191 China

In order to ensure the safety of engine life limited parts （ELLP） according to airworthiness regulations, a numerical approach integrating one-way fluid structure interaction （FSI） and probabilistic risk assessment （PRA） is developed, by which the variation of flow parameters in a rotor-stator cavity on the safety of gas turbine disks is investigated. The results indicate that the flow parameters affect the probability of fracture of a gas turbine disk since they can change the distribution of stress and temperature of the disk. The failure probability of the disk rises with increasing rotation Reynolds number and Chebyshev number, but descends with increasing inlet Reynolds number. In addition, a sampling based sensitivity analysis with finite difference method is conducted to determine the sensitivities of the safety with respect to the flow parameters. The sensitivity estimates show that the rotation Reynolds number is the dominant variable in safety analysis of a rotor-stator cavity among the flow parameters.

关键词： airworthiness aircraft engines engine life limited parts safety analysis rotor-stator cavity risk assessment

Exploring a Promising Region and Enhancing Decision Space Diversity for Multimodal Multi-Objective Optimization

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Tsinghua Science and Technology 2024年第2期29卷 325-342页

作者： Fei Ming Wenyin gong School of Computer Science China University of GeosciencesWuhan 430074China

During the past decade,research efforts have been gradually directed to the widely existing yet less noticed multimodal multi-objective optimization problems(MMOPs)in the multi-objective optimization ***,researchers have begun to investigate enhancing the decision space diversity and preserving valuable dominated solutions to overcome the shortage caused by a preference for objective space ***,many existing methods still have limitations,such as giving unduly high priorities to convergence and insufficient ability to enhance decision space *** overcome these shortcomings,this article aims to explore a promising region(PR)and enhance the decision space diversity for handling *** traditional methods,we propose the use of non-dominated solutions to determine a limited region in the PR in the decision space,where the Pareto sets(PSs)are included,and explore this region to assist in solving ***,we develop a novel neighbor distance measure that is more suitable for the complex geometry of PSs in the decision space than the crowding *** on the above methods,we propose a novel dual-population-based coevolutionary *** studies on three benchmark test suites demonstrates that our proposed methods can achieve promising performance and versatility on different *** effectiveness of the proposed neighbor distance has also been justified through comparisons with crowding distance methods.

关键词： multimodal multi-objective optimization evolutionary algorithms promising region neighbor distance decision space coevolution

On Algebraic Immunity of Trace Inverse Functions on Finite Fields of Characteristic Two

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Journal of Systems Science & Complexity 2016年第1期29卷 272-288页

作者： FENG Xiutao gong Guang Key Laboratory of Mathematics Mechanization Academy of Mathematics and Systems ScienceChinese Academy of Sciences State Key Laboratory of Information Security(Institute of Information Engineering Chinese Academy of Sciences) Department of Electrical and Computer Engineering University of Waterloo

The trace inverse functions Tr(λx^(-1)) over the finite field F_(2~n) are a class of very important Boolean functions and are used in many stream ciphers such as SFINKS,RAKAPOSHI,the simple counter stream cipher(SCSC) presented by Si W and Ding C(2012),*** order to evaluate the security of those ciphers in resistance to(fast) algebraic attacks,the authors need to characterize algebraic properties of Tr(λx^(-1)).However,currently only some bounds on algebraic immunity of Tr(λx^(-1)) are given in the public literature,for example,the NGG upper bound and the Bayev lower bound,*** paper gives the exact value of the algebraic immunity of Tr(λx^(-1)) over F_(2~n),that is,AI(Tr(λx^(-1))) =[2n^(1/2)]- 2,where n ≥ 2,A ∈ F_(2~n) and λ≠ 0,which shows that Dalai's conjecture on the algebraic immunity of Tr(λx^(-1)) is *** is more,the authors demonstrate some weak properties of Tr(λx^(-1)) against fast algebraic attacks.

关键词： Algebraic immunity boolean functions fast algebraic attacks trace inverse functions

Universal adversarial examples and perturbations for quantum classifiers

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National Science Review 2022年第6期9卷 48-55页

作者： Weiyuan gong Dong-Ling Deng Center for Quantum Information Institute for Interdisciplinary Information Sciences (ⅢS) Tsinghua University Shanghai Qi Zhi Institute

Quantum machine learning explores the interplay between machine learning and quantum physics, which may lead to unprecedented perspectives for both fields. In fact, recent works have shown strong evidence that quantum computers could outperform classical computers in solving certain notable machine learning tasks. Yet, quantum learning systems may also suffer from the vulnerability problem: adding a tiny carefully crafted perturbation to the legitimate input data would cause the systems to make incorrect predictions at a notably high confidence level. In this paper, we study the universality of adversarial examples and perturbations for quantum classifiers. Through concrete examples involving classifications of real-life images and quantum phases of matter, we show that there exist universal adversarial examples that can fool a set of different quantum classifiers. We prove that, for a set of k classifiers with each receiving input data of n qubits, an O(ln [k]/2~n) increase of the perturbation strength is enough to ensure a moderate universal adversarial risk. In addition, for a given quantum classifier, we show that there exist universal adversarial perturbations, which can be added to different legitimate samples to make them adversarial examples for the classifier. Our results reveal the universality perspective of adversarial attacks for quantum machine learning systems, which would be crucial for practical applications of both near-term and future quantum technologies in solving machine learning problems.

关键词： quantum machine learning quantum classifiers adversarial examples measure concentration quantum no-free-lunch theorem

Lidar observation campaigns on diurnal variations of the sodium layer in Beijing and Wuhan, China

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Science China Earth Sciences 2015年第8期58卷 1377-1386页

作者： gong ShaoHua YANG GuoTao CHENG XueWu gong Shun Sheng XU JiYao LI FaQuan gong Wei WANG JiHong School of Physics and Electronics Engineering Hainan Normal University State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences Laboratory of Optoelectronics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University

Based on observations from daytime lidars in eastern China,diurnal cycles of the sodium layer over Wuhan(30.5°N,114.6°E)and Beijing(40.5°N,116°E)are *** variations of Na density,root mean square(RMS)layer width,and centroid height of the sodium layer are *** reveal that the large diurnal cycles of the sodium layer are controlled mainly by 24-hr oscillations at the two observation *** diurnal variation of the sodium layer over Wuhan was modulated mainly by tidal perturbations during the lidar observation ***,the diurnal variation over Beijing was controlled principally by photoionization and photochemistry effects during another campaign,and there was little evidence of direct tidal *** comparisons suggest that the diurnal variation of the sodium layer perhaps has obvious regional characteristics across *** variation can be either controlled mainly by tidal perturbations or by photoionization and photochemistry effects in different seasons.

关键词： daytime lidar diurnal variations of the sodium layer photochemistry effects tidal perturbations