检索结果-南通市图书馆

Resilient control of flexible hypersonic vehicles against unmatched distributed faults

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 60-70页

作者： dong zhao Wenjing REN School of Artificial Intelligence Anhui UniversityHefei 230601China Key Laboratory of System Control and Information Processing Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China

This paper studies a robust fault compensation and vibration suppression problem of flexible hypersonic *** controlled plant is represented by a cascade system composed of a nonlinear Ordinary Differential Equation(ODE)and an Euler-Bernoulli Beam Equation(EBBE),in which the vibration dynamics is coupled with the rigid dynamics and suffers from distributed faults.A state differential transformation is introduced to transfer distributed faults to an EBBE boundary and a longitudinal dynamics is refined by utilizing T-S fuzzy IF-THEN rules.A novel T-S fuzzy based fault-tolerant control algorithm is developed and related stability conditions are *** robust exponential stability and well-posedness are proved by using the modified l_(0)-semigroup based Lyapunov direct approach.A simulation study on the longitudinal dynamics of flexible hypersonic vehicles effectively verifies the validity of the developed theoretical results.

关键词： Flexible hypersonic vehicles ODE-EBBE cascade Robust exponential stability Unmatched distributed fault compensation Vibration suppression

Markov selection and W-strong Feller for 3D stochastic primitive equations

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2017年第10期60卷 1873-1900页

作者： dong zhao ZHANG RangRang Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

This paper studies some analytical properties of weak solutions of 3D stochastic primitive equations with periodic boundary conditions. The martingale problem associated to this model is shown to have a family of solutions satisfying the Markov property, which is achieved by means of an abstract selection principle. The Markov property is crucial to extend the regularity of the transition semigroup from small times to arbitrary times. Thus, under a regular additive noise, every Markov solution is shown to have a property of continuous dependence on initial conditions, which follows from employing the weak-strong uniqueness principle and the Bismut-Elworthy-Li formula.

关键词： primitive equations Markov selection W-strong Feller

Robust load-balanced backbone-based multicast routing in mobile opportunistic networks

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2023年第4期17卷 109-125页

作者： Di ZHANG dong zhao uadong MA Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and TelecommunicationsBeijing 100876China

Mobile opportunistic network(MON)is an efficient way of communication when there is no persistent connection between *** in MONs can be used to efficiently deliver messages to multiple destination ***,because multiple destination nodes are involved,multicast routing is more complex than unicast and brings a higher communication ***-based routing can effectively reduce the network overhead and the complexity of routing ***,the load of backbone nodes is larger than that of regular *** the backbone node’s buffer is exhausted,it will have a significant impact on the performance of the routing *** balancing can improve the ability of backbone to deal with the change of network load,and backbone maintenance algorithm can provide backbone *** this paper,we propose a robust load-balanced backbone-based multicast routing scheme in *** the backbone construction algorithm,we transform the problem of backbone construction into a multi-objective optimization problem,and propose a multi-objective evolutionary algorithmbased backbone construction algorithm,namely LBMBCMOEA *** addition,in order to increase the robustness of the backbone-based routing scheme,we propose a localized multicast backbone maintenance algorithm(MBMA)to deal with the buffer exhaustion of backbone *** a backbone node’s residual buffer is insufficient,MBMA algorithm selects other nodes to replace the backbone *** results on extensive simulations show that when considering the node buffer size constraints,compared with previous backbone-based multicast routing schemes,our proposed algorithm has better performance,and when the node’s residual buffer is insufficient,MBMA algorithm can significantly improve the performance of the backbone-based multicast routing scheme.

关键词： mobile opportunistic network multicast multiobjective optimization backbone construction backbone maintenance

Fault Accommodation for a Class of Nonlinear Uncertain Systems With Event-Triggered Input

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第2期9卷 235-245页

作者： dong zhao Marios M.Polycarpou IEEE KIOS Research and Innovation Center of Excellence and the Department of Electrical and Computer EngineeringUniversity of CyprusNicosia 1678Cyprus

The event-triggered fault accommodation problem for a class of nonlinear uncertain systems is considered in this *** control signal transmission from the controller to the system is determined by an event-triggering scheme with relative and constant triggering *** the event-induced control input error and system fault threat,a novel eventtriggered active fault accommodation scheme is designed,which consists of an event-triggered nominal controller for the time period before detecting the occurrence of faults and an adaptive approximation based event-triggered fault accommodation scheme for handling the unknown faults after detecting the occurrence of *** closed-loop stability and inter-event time of the proposed fault accommodation scheme are rigorously *** cases for the fault accommodation design under constant triggering threshold are also *** example is employed to illustrate the effectiveness of the proposed fault accommodation scheme.

关键词： Adaptive control event-triggered control fault accommodation neural networks nonlinear systems

Simulataneous analysis of reactivity of anilines in the hydro gen-isotope exchange reaction

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2005年第6期16卷 352-357页

作者： zhao dong-Yu IMAIZUMI Hiroshi LEI Qing-Quan zhao dong-Mei School of Chemistry and Materials Science Heilongjiang University Harbin 150080 China College of Electrical and Electronic Engineering Harbin University of Science and Technology Harbin 150040 China Department of Chemistry and Chemical Engineering Faculty of Engineering Niigata University Niigata-shi 950-2181 Japan

In order to reveal the reactivity of a functional group in an aromatic compound having two substituents inthe aromatic ring, the hydrogen-isotope exchange reaction (T-H exchange reaction) between tritiated water vapor(HTO vapor) and 4-amino-2-methylbenzenesulfonic acid (and 5-amino-2-methylphenol) were dynamically observedat 50 (and 70 ) in a gas ℃ ℃ -solid system. Consequently, the fact that the specific activity of the acid increased withtime was obtained, and the T-for-H exchange reaction occurred. By applying the A"-McKay plot method to the dataobserved, the rate constant of each functional group for the reaction was obtained. After the additive property of theHammett’s rule was applied to this work, the new substituent constants were obtained. From the above-mentioned,the following four items have been confirmed: (1) the reactivity of the functional groups can be dynamically analyzed,and the A"-McKay plot method is useful to analyze the reactivity; (2) the additive property of the Hammett’s rule isapplicable to quantitative comparison of the reactivity of the functional groups; (3) the reactivity of the functionalgroups can be simultaneously analyzed by using the A"-McKay plot method in the T-H exchange reaction; and (4) themethod used in this work is also useful for analyzing the reactivity of a certain material having some kinds of functional groups.

关键词：放射性同位素芳胺交换反应环境污染

Research progress in Mg-based hydrogen storage alloys

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2014年第5期33卷 499-510页

作者： dong-Liang zhao Yang-Huan Zhang Department of Functional Material Research Central Iron and Steel Research Institute

Magnesium and magnesium-based alloy hydrides remain attractive hydrogen storage materials owing to high hydrogen capacity and rich reserves in the earth＇s crust. A high stability of hydride and sluggish hydriding/dehydriding kinetics at practical temperatures for the materials drove researchers into alloying with other elements, using different preparation techniques, using catalyst and thin film hydride to improve the hydrogen absorption/desorption properties. In this review, the development of these approaches and their effects on the thermodynamic and kinetics properties of magnesium and magnesium-based alloy hydrides were descript in details.

关键词： Magnesium-based storage alloy Thermodynamic and kinetics Preparation technique Alloying and catalyzing

Track-position and vibration control simulation for strut of the Stewart platform

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第4期14卷 281-291页

作者： zhao-dong XU Chen-hui WENG MOE Key Laboratory of C&PC Structures Southeast University Guangzhou Design Institute

Vibrations inherently generated by on-board disturbance sources degrade the performance of the instruments in an on-orbit spacecraft,which have stringent accuracy *** Stewart platform enables both track-positioning and vibration *** strut of the Stewart platform is designed as a piezoelectric(PZT) element in series with a voice coil motor(VCM) element and a viscoelastic *** track-positioning system uses a VCM as the main positioning control driver and a PZT as the positioning *** vibration control system uses the characteristics of struts including active and passive control elements to attenuate the *** results indicate that the Stewart platform with the designed struts has good performance in tracking and vibration attenuation with different interference waves.

关键词： Stewart platform Track-positioning control Vibration control

Novel dye-sensitized solar cell architecture using TiO2-coated Ag nanowires array as photoanode

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2019年第4期38卷 316-320页

作者： Ming Wang Sam Zhang zhao-Fu Du Li-dong Sun dong-Liang zhao Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore 639789 Singapore

With the aim of reducing series resistance and increasing dye loading,novel dye-sensitized solar cell architecture was designed with TiO2 nanoparticle-coated Ag nanowires array as the *** nanowire array was prepared by anodic aluminum oxide (AAO) templateassisted electrochemical deposition ***,Ag nanowires were coated by TiO2 nanoparticles in hydrothermal *** structures of the photoanode were characterized by field emission scanning electron microscopy (FESEM).Ag nanowires are covered by a layer of very fine nanoparticles with a diameter of less than 5 nm.X-ray diffraction (XRD) and selected-area electron diffraction (SAED) show that Ag nanowires have a strong preferred orientation in (220) direction and the TiO2 coating layer is a polycrystalline *** this photoanode,3.2 % conversion efficiency is achieved for the cell sensitized with N3 dye.

关键词： Dye-sensitized solar cell Nano wires array Photoanode Anodic aluminum oxide

Knowledge-oriented modeling for influencing factors of battle damage in military industrial logistics:An integrated method

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第3期16卷 571-587页

作者： Xiong Li Xiao-dong zhao Wei Pu Military Exercise and Training Center Army Academy of Armored ForcesBeijing 100072China

Modeling influencing factors of battle damage is one of essential works in implementing military industrial logistics simulation to explore battle damage laws ***,one of key challenges in designing the simulation system could be how to reasonably determine simulation model input and build a bridge to link battle damage model and battle damage laws *** this paper,we propose a novel knowledge-oriented modeling method for influencing factors of battle damage in military industrial logistics,integrating conceptual analysis,conceptual modeling,quantitative modeling and simulation *** conceptualize influencing factors of battle damage by using the principle of hierarchical decomposition,thus classifying the related battle damage knowledge ***,we construct the conceptual model of influencing factors of battle damage by using Entity-Relations hip approach,thus describing their interactions ***,we extract the important influencing factors by using social network analysis,thus evaluating their importance quantitatively and further clarifying the elements of ***,we develop an agent-based military industry logistics simulation system by taking the modeling results on influencing factors of battle damage as simulation model input,and obtain simulation model output,i.e.,new battle damage laws knowledge,thus verifying feasibility and effectiveness of the proposed *** results show that this method can be used to support human decision-making and action.

关键词： Battle damage Industrial logistics Entity-relationship approach Social network analysis Agent-based simulation