Delay-dependent Robust Stability and Stabilization Criteria for Uncertain Neutral Systems

This paper concerns problem of the delay-dependent robust stability and stabilizationfor uncertain neutral systems. Some new delay-dependent stability criteria are derived by takingthe relationship between the terms in the Leibniz-Newton formula into account. Free weightingmatrices are given to express the relationship between the terms in the Leibniz-Newton formula andthe new criteria are based on linear matrix inequalities such that the free weighting matrices can beeasily obtained. Moreover, the stability criteria are also used to design the state-feedback controller.Numerical examples demonstrates that the proposed criteria are e?ective and are an improvementover the previous papers.

基于模糊决策方法的管道泄漏诊断与定位

A leak detection plays a key role in the overall integrity monitoring for a oil pipeline system. A fuzzy decision-making approach to pipeline leak localization is proposed in this paper.The two main methods, pressure gradient localization and negative pressure wave localization, are combined with fuzzy logical decision-making method to form a novel fault diagnosis scheme. The combination scheme can improve the precision of localization. An application example, 14km long oil pipeline leak detection and localization, is illustrated. This method is compared with others through practical experiments and its validity is confirmed by the results.

Suboptimal Strategies of Linear Quadratic Closed-loop Differential Games: An BMI Approach

The suboptimal control program via memoryless state feedback strategies for LQ differential games with multiple players is studied in this paper. Sufficient conditions for the existence of the suboptimal strategies for LQ differential games are presented. It is shown that the suboptimal strategies of LQ differential games are associated with a coupled algebraic Riccati inequality. Furthermore, the problem of designing suboptimal strategies is considered. A non-convex optimization problem with BMI constrains is formulated to design the suboptimal strategies which minimizes the performance indices of the closed-loop LQ differential games and can be solved by using LMI Toolbox of MATLAB. An example is given to illustrate the proposed results.

A Hierarchy of Lax Integrable Lattice Equations, Liouville Integrability and a NewIntegrable Symplectic Map

A discrete matrix spectral problem and the associated hierarchy of Lax integrable lattice equations are presented, and it is shown that the resulting Lax integrable lattice equations are all Liouville integrahle discrete Hamiltonian systems. A new integrable symplectie map is given by binary Bargmann constraint of the resulting hierarchy.Finally, an infinite set of conservation laws is given for the resulting hierarchy.

On delay-dependent robust stability for uncertain neutral systems

The problem of delay-dependent criteria for the robust stability of neutral systems with time-varying structured uncertainties and identi-cal neutral-delay and discrete-delay is concerned. A criterion for nominal systems is presented by taking the relationship between the terms in the Leibniz-Newton formula into account, which is described by some free-weighting matrices. In addition, this criterion is extended to robust stability of the systems with time-varying structured uncertainties. All of the criteria are based on linear matrix inequality such that it is easy to calculate the upper bound of the time-delay and the free-weighting matrices. Numerical examples illustrate the effectiveness and the improvement over the existing results.

The Reduced-order Design of Robust Adaptive Backstepping Controller

For a class of systems with unmodeled dynamics, robust adaptive stabilization problemis considered in this paper. Firstly, by a series of coordinate changes, the original system is re-parameterized. Then, by introducing a reduced-order observer, an error system is obtained. Basedon the system, a reduced-order adaptive backstepping controller design scheme is given. It is provedthat all the signals in the adaptive control system are globally uniformly bounded, and the regulationerror converges to zero asymptotically. Due to the order deduction of the controller, the design schemein this paper has more practical values. A simulation example further demonstrates the e?ciency ofthe control scheme.

具有时变时滞的Lurie系统绝对稳定性的时滞相关条件

Some delay-dependent absolute stability criteria for Lurie control systems with timevarying delay are derived, in which some free-weighting matrices are used to express the relationships between the terms in the Leibniz-Newton formula. These criteria are based on linear matrix inequality(LMI) such that the upper bound of time-delay guaranteeing the absolute stability and the free-weighting matrices can be obtained through the solutions of the LMI. Moreover, the Lyapunov functional constructed by the solutions of these LMIs is adopted to guarantee the absolute stability of the systems. Finally, some examples axe provided to demonstrate the effectiveness of the proposed methods.

Application of an expert system using neural network to control the coagulant dosing in water treatment plant

The coagulation process is one of the most important stages in water treatment plant, which involves many complex physical and chemical phenomena. Moreover, coagulant dosing rate is non-linearly correlated to raw water characteristics such as turbidity, conductivity, PH, temperature, etc. As such, coagulation reaction is hard or even impossible to control satisfactorily by conventional methods. Based on neural network and rule models, an expert system for determining the optimum chemical dosage rate is developed and used in a water treatment work, and the results of actual runs show that in the condition of satisfying the demand of drinking water quality, the usage of coagulant is lowered.

A hybrid genetic algorithm based on mutative scale chaos optimization strategy

In order to avoid such problems as low convergent speed and local optimalsolution in simple genetic algorithms, a new hybrid genetic algorithm is proposed. In thisalgorithm, a mutative scale chaos optimization strategy is operated on the population after agenetic operation. And according to the searching process, the searching space of the optimalvariables is gradually diminished and the regulating coefficient of the secondary searching processis gradually changed which will lead to the quick evolution of the population. The algorithm hassuch advantages as fast search, precise results and convenient using etc. The simulation resultsshow that the performance of the method is better than that of simple genetic algorithms.

Analysis of Chaotic Synchronization Stability and Its Application to a Two-dimensional Advertising Competing Model

A class of map in which chaotic synchronization can occur is defined. The transverse Lyapunov exponents are used to determine the stability of synchronized trajectories. Some complex phenomena closely related to chaotic synchronization, namely riddled basin, riddling bifurcation and blowout bifurcation are theoretically analyzed. Riddling bifurcation and blowout bifurcation may change the synchronization stability of the system. And two types of riddled basins, i.e., global riddled basin and local riddled basin, may come into being after riddling bifurcation. An advertising competing model based on Vidale-Wolfe model is proposed and analyzed by the above theories at the end of the paper.

An Ontology-Based Service Matching Strategy in Grid Environments

An efficient ontology-based service scarching scheme is put forward in this paper by introducing semantic information into grid systems. The ideas of ontology and OWL (Web ontology language) are applied to establish a uniform abstract concept model and standardization for grid services. We propose a general framework of ontology-based service discovery sub-system, which includes ontology storage module, context-based domain selection module and specific service matching module. Implementation policies are also presented in this paper. Key words ontology - grid - service matching - scmantic - service composition CLC number TP 393 Foundation item: Supported by High Technology Research and Development Program of China (2003AA414210) and National Natural Science Foundation of China (60173051)Biography: YIN Nan (1979-), male, Master student, research di rection: Web service, grid, distributed system.

Parameter-dependent Lyapunov functional for systems with multiple time delays

The separation of the Lyapunov matrices and system matrices plays an important role when one uses parameter-dependent Lyapunov functional handling systems with polytopic type uncertainties. The delay-dependent robust stability problem for systems with polytopic type uncertainties is discussed by using parameter-dependent Lyapunov functional. The derivative term in the derivative of Lyapunov functional is reserved and the free weighting matrices are employed to express the relationship between die terms in the system equation such that the Lyapunov matrices are not involved in any product terms with the system matrices. In addition, the relationships between the terms in the Leibniz Newton formula are also described by some free weighting matrices and some delay-dependent stability conditions are derived. Numerical examples demonstrate that the proposed criteria are more effective than the previous results.

Irregular and regular LDPC codes with high spectrum efficiency modulation in image transmission over fading channel

If the degree distribution is chosen carefully, the irregular low-density parity-check (LDPC) codes can outperform the regular ones. An image transmission system is proposed by combining regular and irregular LDPC codes with 16QAM/64QAM modulation to improve both efficiency and reliability. Simulaton results show that LDPC codes are good coding schemes over fading channel in image communication with lower system complexity. More over, irregular codes can obtain a code gain of about 0.7 dB compared with regular ones when BER is 10 -4. So the irregular LDPC codes are more suitable for image transmission than the regular codes.

Towards Single-component Molecular Conductor[Ni(dmit)2]by Charge Disproportionation:2[Ni(dmit)2]^0.5→[Ni(dmit)2]+[Ni(dmit)2]^-

A new method of synthesizing single-component molecular conductor [Ni(dmit)2] by the reaction 2(Me4N)[Ni(dmit)2]2 [Ni(dmit)2] + (Me4N)[Ni(dmit)2] is reported. [Ni(dmit)2] exhibits a semiconductive behavior above 167 K, while from 167 K down to the measuring limit of 60 K, it exhibits metallic conductivity.

EFFICIENT IMAGE TRANSMISSION SCHEME IN FMT SYSTEM

An efficient image transmission scheme is proposed based on byte partition and adaptive sub-channel distribution technique in Filtered MultiTone (FMT) system over frequency selective slow fading channel. According to the simulation results and analysis of a typical image with matlab, improvement in Peak Signal to Noise Ratio (PSNR) of the received image and low complexity for equalization is demonstrated remarkably. Comparing with no adaptive and no actual channel equalization scheme, the proposed scheme saves over 6 dB when PSNR=40 dB.

Robust H-infinity reliable control for a class of nonlinear uncertain neutral delay systems

This paper focuses on the robust H-infinity reliable control for a class of nonlinear neutral delay systems with uncertainties and actuator failures. We design a state feedback controller in terms of linear matrix inequality(LMI)such that the plant satisfies robust H-infinity performance for all admissible uncertainties, and actuator failures among a prespecified subset of actuators. An example is also given to illustrate the effectiveness of the proposed approach.

A New Method of CT Medical Images Contrast Enhancement

A new method of contrast enhancement is proposed in the paper using multiscale edge representation of images, and is applied to the field of CT medical image processing. Comparing to the traditional Window technique, our method is adaptive and meets the demand of radiology clinics more better. The clinical experiment results show the practicality and the potential applied value of our method in the field of CT medical images contrast enhancement.