卫星图像的格矢量量化编码压缩方法研究

卫星图像是一个种高熵值图像,本文针对卫星图像研究了格矢量量化编码压缩方法,分析了格矢量量化特性,并列举了几种格。实验结果表明,格矢量量化编码压缩方法失真小,计算量少,比较适用于卫星图像编码压缩。     

过程系统仿真中的分离技术

首先阐述了过程系统建模与仿真发展的现状,并就目前过程系统建模与仿真的智能化,集成化的需要,阐述了过程系统建模与仿真中的管线与设备分离,算法与数据分离,环境与模型分离的设计思想,最后,给出了应用系统的体系结构。     

过程系统训练仿真器的面向对象分析与设计

针对过程系统训练仿真所存在的问题,结合面向对象的系统分析与设计的特点,提出了基于Ｂｒｏｗｓｅｒ／Ｓｅｖｅｒ体系结构的采用面向对象技术设计的新型过程训练仿真系统的结构及其实现思路。     

水库调度PSO优化模型及求解方法

水库优化调度是水资源系统工程的一个典型,其实质是一个非线性的不等式约束优化问题,然而现行的求解方法中针对离散精度和复杂约束处理两个问题一直考虑不足,相关方面的研究也较少。将连续域寻优的粒子群算法引入到水资源系统工程中,建立水库调度的PSO优化模型,避免因离散而引起的寻优瓶颈,并针对传统粒子群算法的趋同性问题和复杂约束问题,提出退火罚函数法和混沌变异因子法,使改进后的粒子群能更有效地解决水库调度问题。通过实例分析,验证该方法的可靠性,为水库调度提供了一种新的求解途径。     

船舶航向与柴油主机联合LPV鲁棒控制及仿真

船舶航向与柴油机推进装置是紧密耦合的,但长期以来对它们的控制是完全独立的.根据线性变参数(LPV)系统设计原理,提出了基于LPV的船舶航向与主机联合控制.建立了以船速等为变参数的船舶航向与主机联合控制的LPV模型,采用LPV多胞设计方法,通过状态反馈对闭环极点进行配置,分别设计具有H∞鲁棒性能的航向与主机LPV控制器,实现二者的联合控制.以5446箱班轮为被控制对象,仿真验证了航向与主机LPV控制器在风浪干扰下联合控制的有效性.     

Investigation on full distribution CNC system based on SERCOS bus

A full distribution CNC system based on SERCOS bus is studied in accordance with the limitations of traditional PC-based motion card. The conventional PC-based motion control card is dispersed into several autonomous intelligent servo-control units with the function of servo driver. The autonomous intelligent servocontrol units realize the loop control of position, velocity and current. Interpolation computation is completed in PC and the computational results are transferred to every autonomous intelligent servo-control unit by high speed SERCOS bus. Software or hardware synchronization technology is used to ensure all servomotors are successive and synchronously running. The communication and synchronization technology of SERCOS are also researched and the autonomous intelligent servo-control card is developed byself. Finally, the experiment of circle contour process on a prototype system proves the feasibility.     

Non-fragile decentralized H∞ controller design for uncertain linear systems

Considering the design problem of non-fragile decentralized H∞ controller with gain variations, the dynamic feedback controller by measurement feedback for uncertain linear systems is constructed and studied. The parameter uncertainties are considered to be unknown but norm bounded. The design procedures are investigated in terms of positive definite solutions to modify algebraic Riccati inequalities. Using information exchange among local controllers, the designed non-fragile decentralized H∞ controllers guarantee that the uncertain closed-loop linear systems are stable and with H∞ -norm bound on disturbance attenuation. A sufficient condition that there are such non-fragile H∞ controllers is obtained by algebraic Riccati inequalities. The approaches to solve modified algebraic Riccati inequalities are carried out preliminarily. Finally, a numerical example to show the validity of the proposed approach is given.     

Research on secure buyer-seller watermarking protocol

A new buyer-seller watermarking protocol is proposed by applying a double encryption method and a novel mechanism of embedding a buyer＇s watermark. The protocol can effectively prevent against collusion attacks and the man in the middle attack if the third party is not trusted. Also, based on the proposed scheme for the first-hand transaction, a new buyer-reseller watermarking protocol and a formal multi-party watermarking protocol are also proposed. The proposed buyer-resell watermarking protocol only needs the original seller to provide transfer certificate and encryption-decryption service to support the second-hand transaction, and the multi-party watermarking protocol with distributed certificate authorities can overcome the difficulty in the combination of multicast mechanism with multiple unique watermarks and allow a seller to multicast the watermarked digital contents and key transaction information to n buyers. Furthermore, the idea of zero knowledge proof is also applied into the proposed scheme to allow the seller to take an effective control on the task performed by the third party.     

Cluster Synchronization in a Complex Dynamical Network with Two Nonidentical Clusters

This paper further investigates cluster synchronization in a complex dynamical network with two-cluster. Each cluster contains a number of identical dynamical systems, however, the subsystems composing the two clusters can be different, i.e., the individual dynamical system in one cluster can differ from that in the other cluster. Complete synchronization within each cluster is possible only if each node from one cluster receives the same input from nodes in other cluster. In this case, the stability condition of one-cluster synchronization is known to contain two terms： the first accounts for the contribution of the inner-cluster coupling structure while the second is simply an extra linear term, which can be deduced by the ＂same-input＂ condition. Applying the connection graph stability method, the authors obtain an upper bound of input strength for one cluster if the first account is known, by which the synchronizability of cluster can be scaled. For different clusters, there are different upper bound of input strength by virtue of different dynamics and the corresponding cluster structure. Moreover, two illustrative examples are presented and the numerical simulations coincide with the theoretical analysis.     

Robust H∞ control for neutral stochastic uncertain systems with time-varying delay

The problem of robust H∞ control for uncertain neutral stochastic systems with time-varying delay is discussed. The parameter uncertaintie is assumed to be time varying norm-bounded. First, the stochastic robust stabilization of the stochastic system without disturbance input is investigated by nonlinear matrix inequality method. Then, a full-order stochastic dynamic output feedback controller is designed by solving a bilinear matrix inequality (BMI), which ensures a prescribed stochastic robust H∞ performance level for the resulting closed loop system with nonzero disturbance input and for all admissible uncertainties. An illustrative example is provided to show the feasibility of the controller and the potential of the proposed technique.