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Observer-based Variable Universe Adaptive Fuzzy Controller Without Additional Dynamic Order

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International Journal of Automation and computing 2014年第4期11卷 418-425页

作者： Hai-Gang Guo bao-Jie zhang School of Mathematics and Statistics Henan University of Science and Technology School of Mathematics and Information Science Qujing Normal University

A high-precision fuzzy controller, based on a state observer, is developed for a class of nonlinear single-input-single-output(SISO) systems with system uncertainties and external disturbances. The state observer is introduced to resolve the problem of the unavailability of state variables. Assisted by the observer, a variable universe fuzzy system is designed to approximate the ideal control law. Being auxiliary components, a robust control term and a state feedback control term are designed to suppress the influence of the lumped uncertainties and remove the observation error, respectively. Different from the existing results, no additional dynamic order is required for the control design. All the adaptive laws and the control law are built based on the Lyapunov synthesis approach, and the signals involved in the closed-loop system are guaranteed to be uniformly ultimately bounded. Simulation results performed on Duffing forced oscillation demonstrate the advantages of the proposed control scheme.

关键词： Variable universe fuzzy system observer strictly positive real (SPR) condition dynamic order σ-modification adaptive bounding technique

Accumulated-state-error-based event-triggered sampling scheme and its application to H∞ control of sampled-data systems

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Science China(Information Sciences) 2024年第6期67卷 328-341页

作者： Xian-Ming zhang Qing-Long HAN bao-Lin zhang Xiaohua GE Dawei zhang School of Science Computingand Engineering TechnologiesSwinburne University of Technology College of Automation and Electronic Engineering Qingdao University of Science & Technology School of Mathematics Shandong University

This paper is concerned with event-triggered H∞control of sampled-data systems. Its novelties lie in three aspects:（i） A novel accumulated-state-error-based event-triggered scheme is introduced by comparing the integral of the state error from tk to t with the system state sampled at tk. This condition works well due to the fact that the so-called Zeno behaviour does not occur.（ii） A novel Lyapunov functional is constructed to establish a criterion to ensure some certain H∞performance of the closed-loop system. This Lyapunov functional is dependent on the integral of the state error involved in the event-triggered scheme.（iii） Under the event-triggered sampling scheme, suitable state-feedback controllers can be designed rather than be given a priori. Moreover, a self-triggered implementation of the proposed event-triggered sampling scheme is presented as well. Finally, a batch reactor model and an inverted pendulum system are given to demonstrate the effectiveness of the proposed method.

关键词： event-triggered sampling self-triggered implementation H ∞ control looped-functional

Ideal Strengths and Bonding Properties of PuO_(2)under Tension

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Chinese Physics Letters 2011年第4期28卷 178-181页

作者： WANG bao-Tian zhang Ping Institute of Theoretical Physics and the Department of Physics Shanxi UniversityTaiyuan 030006 LCP Institute of Applied Physics and Computational MathematicsBeijing 100088

We perform a first-principles computational tensile test on PuO_(2)based on density-functional theory within a local density approximation(LDA)+U formalism to investigate its structural,mechanical,magnetic and intrinsic bonding properties in four representative directions:[001],[100],[110]and[111].The stress-strain relations show that the ideal tensile strengths in the four directions are 81.2,80.5,28.3 and 16.8 GPa at strains of 0.36,0.36,0.22 and 0.18,***[001]and[100]directions are prominently stronger than the other two directions since more Pu-0 bonds participate in the pulling *** charge and density of state analysis along the[001]direction,we find that the strong mixed ioni%ovalent character of the Pu-0 bond is weakened by tensile strain and PuO_(2)will exhibit an insulator-to-metal transition after tensile stresses exceeding about 79 GPa.

关键词： process strain directions

The Hyperspace of the Regions below Continuous Maps with the Fell Topology

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Acta Mathematica Sinica,English Series 2012年第1期28卷 57-66页

作者： Zhong Qiang YANG bao Can zhang Department of Mathematics Shantou UniversityShantou 515063P.R.China Chengyi College Jimei UniversityXiamen 361021P.R.China

For a Tychonoff space X, we use ↓USCF（X） and↓CF（X） to denote the families of the hypographs of all semi-continuous maps and of all continuous maps from X to I = [0, 1] with the subspace topologies of the hyperspace Cldf（X × I） consisting of all non-empty closed sets in X × I endowed with the Fell topology. In this paper, we shall show that there exists a homeomorphism h： ↓USCF（X） → Q = [-1, 1]^∞ such that h（↓ CF（X））： co ： {（Xn） E Q ｜ limn→ ∞ xn = O} if and only if X is a locally compact separable metrizable space and the set of isolated points is not dense in X.

关键词： Fell topology hyperspace upper semi-continuous Hilbert cube

Experimental observation on a small-scale thermoacoustic prime mover

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第2期8卷 205-209页

作者： JIN Tao zhang bao-sen TANG Ke bao Rui CHEN Guo-bang Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China

A miniature thermoacoustic prime mover, consuming heat to radiate sound, may be considered as a potential way of heat management in microcircuits because of its simplicity and stability. A prototype with variable resonant tube length of 10 to 25 cm was built, and experiments were carried out to observe its performance, such as onset temperature, oscillation amplitude and operating frequency. The results with atmospheric air showed that proper structures and operating conditions can make the system start an oscillation at a temperature lower than 100 ℃, which proves the feasibility of potential usage in electronic units. The influences of stack position, heat input power or tube inclination on the oscillation amplitude, onset temperature and operating frequency are also presented.

关键词： Thermoacoustics Miniaturization Onset temperature

A novel posture alignment system for aircraft wing assembly

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第11期10卷 1624-1630页

作者： Bin zhang bao-guo YAO Ying-lin KE College of Mechanical and Energy Engineering Zhejiang University Hangzhou 310027 China

A novel 6-degree of freedom (DOF) posture alignment system, based on 3-DOF positioners, is presented for the assembly of aircraft wings. Each positioner is connected with the wing through a rotational and adsorptive half-ball shaped end-effector, and the positioners together with the wing are considered as a 3-PPPS (P denotes a prismatic joint and S denotes a spherical joint) redundantly actuated parallel mechanism. The kinematic model of this system is established and a trajectory planning method is introduced. A complete analysis of inverse dynamics is carried out with the Newton-Euler algorithm, which is used to find the desired actuating torque in the design and path planning phase. Simulation analysis of the displacement and actuating torque of each joint of the positioners based on inverse kinematics and dynamics is conducted, and the results show that the system is feasible for the posture alignment of aircraft wings.

关键词： Aircraft wings Three-coordinate positioner Posture alignment Kinematics Dynamics

An optimization model for fragmentation-based routing in delay tolerant networks

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Science China(Information Sciences) 2016年第2期59卷 185-200页

作者： Xuyan bao Yong zhang Da GUO Mei SONG School of Electronic Engineering Beijing University of Posts and Telecommunications

The explosive growth of mobile data traffic has raised big penetration to cellular network. Fortunately, offloading part of traffic through Delay Tolerant Network(DTN) would be a promising option to relieve load pressure. However, the existing routing strategies designed for DTNs are inappropriate in offloading scenario, where i) large data item would take on the dominance of mobile traffic, ii) centralized control can be exploited with merge between DTN and cellular network. To improve the routing performance of large data transmission, we propose a novel optimization model by creating two-tier solution space based on fragmentation,maximizing the probability that the requested data item is successfully delivered before expiration, taking limited buffer space as constraint metric. Moreover, a specific routing scheme is instantiated from our model, which is supported by uniform fragmentation and fine-grained path selection. Extensive trace-driven simulations show that our scheme is more appropriate for offloading case with outstanding performance in terms of replication overhead and acceptable routing capability.

关键词： multi-path routing delay tolerant networks optimization model data offloading stochastic orderings

Analysis of electrical performances of planar active phased array antennas with distorted array plane

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Journal of Systems Engineering and Electronics 2009年第4期20卷 726-731页

作者： Wang Congsi bao Hong zhang Fushun Feng Xingang Key lab. of Electronic Equipment Structure of Ministry of Education Xidian Univ. Xi'an 710071 P. R. China National Key lab. of Antenna and Microwave Technology Xidian Univ. Xi'an 710071 P. R. China

The influence of the distorted plane of the active phased array antenna on the electromagnetic performance is of great significance to the research on and development of the high-performance antennas. On the bent and bowl-shape distortion, the model is established of the relationship between the electromagnetic performance and the position error of the radiated elements. The method is presented of analyzing the far-field pattern of the distorted rectangular active phased array antenna. The analysis results of a planar phased array antenna with different distortions grades prove the validity of the model. Therefore, by the method, the antenna designers may set the reasonable requirement on the structural tolerance in manufacturing antenna.

关键词： active phased array antenna distortion error radiated element structural tolerance

Experimental Study on Measurement and Calculation of Heat Flux in Supersonic Combustor of Scramjet

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Journal of Thermal Science 2015年第3期24卷 254-259页

作者： zhang Cong YAO Zhanli QIN Jiang bao Wen Harbin Institute of Technology

An experimental measurement and calculation method which consist of thermal response model, convergence criteria and control algorithms, is proposed in this paper for the determination of heat flux in a scramjet combus- tot. Numerical simulations are done to evaluate the effectiveness of the proposed method, and experiments are made in the direct-connect hydrocarbon fueled scramjet combustor of Mach-6 flight for different equivalence ra- tios. The distribution of heat flux along the axial and circumferential directions can be obtained using the pro- posed method. The distribution of heat flux is uneven which is caused by the aerodynamic heating, combustion heat release and changes of section area, and the peak heat flux can be more than 2MW/m^2 during the experi- ments. Heat flux increases with the increase in equivalence ratio for the same Mach number. And axial distribu- tion of heat flux is uniform for different equivalence ratios. In addition, the combustion heat release area of the combustion chamber can therefore be concluded which is useful for guiding the structural design of the thermal protection system.

关键词： Scramjet Heat flux Thermal response model Thermal protection