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Predictive sliding-mode control of networked high-order fully actuated systems under random deception attacks

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Science China(Information Sciences) 2023年第9期66卷 50-63页

作者： da-Wei ZHANG Guo-Ping LIU Center for Control Theory and Guidance Technology Harbin Institute of Technology Center for Control Science and Technology Southern University of Science and Technology

This research addresses the output tracking of networked high-order fully actuated(NHOFA)systems under random deception attacks in the sensor to networked controller(SNC) and networked controller to actuator(NCA) communication channels, where a Bernoulli process represents the launching success rate of random deception attacks. A successful attack involves the output and control signals being tampered with by the injection of false data. Herein, a predictive sliding-mode control scheme is proposed to achieve the security tracking. In this scheme, a sliding-mode variable is introduced to defend the random deception attacks by enhancing the robustness of closed-loop systems. An incremental HOFA(IHOFA) prediction model is developed using a Diophantine equation as an alternative to the traditional reduced-order prediction model. Through this IHOFA prediction model, the multistep ahead predictions of the sliding-mode variable are constructed to optimize the tracking performance and defense of random deception attacks. By utilizing the Lyapunov function and linear matrix inequality(LMI) approach, a sufficient and necessary condition is proposed to ensure stability and high tracking performance of closed-loop NHOFA systems. Herein, an experiment on the tracking control of an air-bearing spacecraft(ABS) simulator is performed to demonstrate the effectiveness and practicability of the predictive sliding-mode control scheme.

关键词： NHOFA systems random deception attacks predictive sliding-mode control stability and tracking performance tracking control of ABS simulator

A sample of active galactic nuclei with strong soft X-ray variabilities

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Science China(Physics,Mechanics & Astronomy) 2015年第4期58卷 101-108页

作者： BI da LIU Teng WANG JunXian CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of China

Large-amplitude X-ray variation is a special feature of AGN, reflecting possible extreme change in the central engine or the ab- sorption along the line of sight. Till now there are only a few relevant studies on individual sources or rather small samples. In this work we aim to perform a systematic study of AGNs with strong soft X-ray variations at timescale of 〉 10 years. To build the sample, we compare the soft X-ray fluxes of AGNs measured in ROSAT All-Sky Survey （RASS） during 1990-1991 with those measured by XMM-Newton during 2000-2009. This investigation bings forth to a sample of 13 AGNs, which appeared bright in RASS era, and went into low states （flux dropped by a factor of 〉 10） when they were caught by XMM-Newton. Most of the 13 sources are type I Seyfert galaxies. 5 of them are noticed to have strong X-ray vai＇iation for the first time. We study the nature of their variations through performing XMM-Newton spectral analyses and by collecting reports from the existing literature. We find the sample could be divided into three categories according to the possible causes of the strong X-ray variations. The variations in MRK 0478 and 1H 0419-557 are consistent with strong light-bending effect, i.e., the observed X-ray flux drops significantly as the X-ray emitting corona gets much closer to the central black hole. The variations in ESO 140-G043 and NGC 7158 are caused by absorption changes along the line of sight. For one special case MRK 0335, the variation can be explained by either light-bending or absorption variation. In the rest 8 sources （- 60%）, the strong soft X-ray variations are likely to exist due to intrinsic changes in the activities of the corona, although in some of them without high quality X-ray spectra we are unable to rule out alternative models. This sample provides good targets for future monitoring campaigns with more extensive studies.

关键词： soft X-ray active galactic nuclei variation

Application of Wavelets Transform to Fault Detection in Rotorcraft UAV Sensor Failure

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Journal of Bionic Engineering 2007年第4期4卷 265-270页

作者： Jun-tong Qi Jian-da Han Shenyang Institute of Automation Chinese Academy of Sciences Shenyang 110016 P. R. China Graduate School Chinese Academy of Sciences Beijing 100049 P. R. China

This paper describes a novel wavelet-based approach to the detection of abrupt fault of Rotorcrafi Unmanned Aerial Vehicle （RUAV） sensor system. By use of wavelet transforms that accurately localize the characteristics of a signal both in the time and frequency domains, the occurring instants of abnormal status of a sensor in the output signal can be identified by the multi-scale representation of the signal. Once the instants are detected, the distribution differences of the signal energy on all decomposed wavelet scales of the signal before and after the instants are used to claim and classify the sensor faults.

关键词： RUAV wavelet transform fault detection sensor failure

Some properties of linguistic preference relation and its ranking in group decision making

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Journal of Systems Engineering and Electronics 2010年第2期21卷 244-249页

作者： Yejun Xu Qingli da Xinwang Liu Business School Hohai University Nanjing 210098 E R. China School of Economics and Management Southeast University Nanjing 210096 P. R. China

The group decision making problem with linguistic pref- erence relations is studied. The concept of additive consistent linguistic preference relation is defined, and then some properties of the additive consistent linguistic preference relation are studied. In order to rank the alternatives in the group decision making with the linguistic preference relations, the weighted average is first utilized to combine the group linguistic preference relations to one linguistic preference relation, and then the transformation function is proposed to transform the linguistic preference relation to the multiplicative preference relation, and thus the Saaty＇s eigenvec- tor method （EM） of multiplicative preference relation is utilized to rank the alternatives in group decision making with the linguistic preference relations. Finally, an illustrative numerical example is given to verify the proposed method. A comparative study to the linguistic ordered weighted averaging （LOWA） operator method is also demonstrated.

关键词： group decision making linguistic preference relations additive consistency rank.

Investigation of high power laser coatings

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光学精密工程 2005年第4期13卷 471-479页

作者： SHAO Jian-da FAN Zheng-xiu R＆D Center for Optical Thin Film Coating Technology Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China

High laser-induced damage threshold and large aperture were focuses on the studies of high power laser coatings. This paper reports the research activities at our center. Several measures were developed for evaluating characters of laser damage, including determination of laser induced damage threshold and detection of absorption based on surface thermal lensing technique. Defect was deemed to be the initial source of laser damage, and was the main factor restricting the laser damage resistance of optical coatings. The contribution of several kinds of typical defects to laser damage was analyzed, and some deposition measures were adopted to control and eliminate the origin of defect. Furthermore, some post-treatment methods were also employed to alleviate the influence of the defect and to improve the laser damage resistance. Correction mask was introduced to improve the thickness uniformity, and the thickness uniformity can be amended to less than 1% in the range of Φ650 mm. Preliminary investigation related to surface deformation was also conducted.

关键词：激光涂覆技术 LidT 吸收能力激光器

ON MAXIMA OF DUAL FUNCTION OF THE CDT SUBPROBLEM

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Journal of Computational Mathematics 2001年第2期19卷 113-124页

作者： Xiong-da Chen Ya-xiang Yuan Reserach Development Center of Parallel Software Institute of SoftwareBeijing 100080China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Ssientific/Engineering ComputingAcademy of Mathematics and Systems SciencesChinese Academy of SciencesBeijing 100080China

Focuses on a study which determined the geometry meaning of the maxima of the CDT mathematical subproblem's dual function. Properties of trust region subproblem; Approximation of the CDT feasible region; Relations bet... 详细信息

关键词： trust region subproblem global minimizer approximation

Integrated criteria for covert channel auditing

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第6期9卷 737-743页

作者： Chang-da WANG Shi-guang JU School of Computer Science and Telecommunications Engineering Jiangsu University Zhenjiang 212013 China School of Computer Science Carleton University Ottawa Ontario K1S 5B6 Canada

A new concept, the security level difference of a covert channel, is presented, which means the security level span from the sender to the receiver of the covert channel. Based on this, the integrated criteria for covert channel auditing are given. Whereas TCSEC (Trusted Computer System Evaluation Criteria) or CC (Common Criteria for Information Technology Security Evaluation) only use the bandwidth to evaluate the threat of covert channels, our new criteria integrate the security level difference, the bandwidth sensitive parameter, bandwidth, duration and instantaneous time of covert channels, so as to give a comprehensive evaluation of the threat of covert channels in a multilevel security system.

关键词： Multilevel security Covert channel Covert channel auditing

Effects of yaw-roll coupling ratio on the lateral-directional departure prediction and restraint

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Chinese Journal of Aeronautics 2019年第10期32卷 2239-2253页

作者： Lin SHEN da HUANG Genxing WU College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

The experimental data obtained from yaw-roll coupled wind tunnel tests are used for lateral-directional departure prediction,by linearizing the_b model to extract nominal dynamic derivatives at each coupling *** prediction results are compared with those of the existing engineering methods which are based on the conventional aerodynamic *** comparison shows that the yaw-roll coupling ratio has a great influence on the departure *** departure resistance will loss in partial region of the coupling ratio when the angle of attack is higher than a critical *** to the stable and unstable regions of coupling ratio,a two-segment stability augmentation system with two different feedback gain matrices is obtained by pole-placement *** two-segment stability augmentation system is used in the simulations of straight and level flight,steady turn,spin recovery and Herbst *** simulation results are also compared with the applications of a fixed-gain stability augmentation system designed by the conventional aerodynamic *** the yaw-roll coupling effects are fully considered,the two-segment stability augmentation system is more effective for departure restraint and can provide a better flying quality with less control energy.

关键词： Lateral-directional departure Stability augmentation system Stability criterion Unsteady aerodynamics Yaw-roll coupling

Reconstruction Method for Running Shape of Rotor Blade Considering Nonlinear Stiffness and Loads

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Journal of Thermal Science 2017年第5期26卷 431-439页

作者： WANG Yongliang KANG da ZHONG Jingjun Marine Engineering College Dalian Maritime University Dalian 116026 China

The aerodynamic and centrifugal loads acting on the rotating blade make the blade configuration deformed comparing to its shape at rest. Accurate prediction of the running blade configuration plays a significant role in examining and analyzing turbomachinery performance. Considering nonlinear stiffness and loads, a reconstruction method is presented to address transformation of a rotating blade from cold to hot state. When calculating blade deformations, the blade stiffness and load conditions are updated simultaneously as blade shape varies. The reconstruction procedure is iterated till a converged hot blade shape is obtained. This method has been employed to determine the operating blade shapes of a test rotor blade and the Stage 37 rotor blade. The calculated results are compared with the experiments. The results show that the proposed method used for blade operating shape prediction is effective. The studies also show that this method can improve precision of finite element analysis and aerodynamic performance analysis.

关键词： Blade reconstruction Fluid-structure interaction Aeroelasticity Nonlinearity