基于移动网络的重构技术研究

根据移动网络的特性并结合其管理方式 ,提出了一种新的基于移动网络并具有一定 Qo S保证的网络重组策略 ,将引入的重新划分网络边界和周界的思想 ,与启用备用链路、重路由等几种机制有机地结合起来 .它不仅完善了现有的重组技术 ,而且还可以作为网络管理中的新功能 ,增强故障处理、性能监测能力 ,提高服务质量 ,保证信息安全可靠地传输 .     

一种基于基因重组策略的遗传算法

为了克服标准遗传算法的早熟现象,提高遗传算法的全局收敛性,文章提出了一种基于基因重组策略的遗传算法,该算法定义了一种新的交叉算子,即移位逻辑交叉算子(包括循环移位交叉算子和洗牌移位交叉算子),用它们对染色体的部分基因实现有规律的重组。实验结果表明,该算法比经典的遗传算法具有更好的收敛性和稳定性。     

An integrated runtime QoS-aware middleware framework for distributed multimedia applications

Future-generation distributed multimedia applications are expected to be highly scalable to a wide variety of heterogeneous devices, and highly adaptive across wide-area distributed environments. This demands multiple stages of run-time support in QoS-aware middleware architectures, particularly, probing the performance of QoS parameters, instantiating the initial component configurations, and adapting to on-the-fly variations. However, few of the past experiences in related work have shown comprehensive run-time support in all of the above stages – they often design and build a middleware framework by focusing on only one of the run-time issues. In this paper, we argue that distributed multimedia applications need effective run-time middleware support in all these stages to be highly scalable and adaptive across a wide variety of execution environments. Nevertheless, the design of such a middleware framework should be kept as streamlined and simple as possible, leading to a novel and integrated run-time middleware platform to unify the probing, instantiation and adaptation stages. In addition, for each stage, the framework should enable the interaction of peer middleware components across host boundaries, so that the corresponding middleware function can be performed in a coordinated and coherent fashion. We present the design of such an integrated architecture, with a case study to illustrate how it is simple yet effective to monitor and configure complex multimedia applications.     

配电网络重构的现状和发展

配电网络重构是配电自动化的重要组成部分 ,是系统安全经济运行的重要举措。回顾了配电网络重构的历史和发展现状 ,对各种重构方法进行了详细评述 ,分析了各算法的特点、存在的问题 ,以促进该研究领域的进一步发展     

Efficient Internet Multicast Routing Using Anycast Path Selection

A novel efficient and dynamic multicast routing protocol based on anycast routing techniques is presented. The contributions of the protocol differ from well-known shared-tree systems in two aspects: (1) Off-tree anycast routing: The nodes in the shared tree are formed into a virtual anycast group and multicast sources use anycast routing to select a better path from the source to one router in the group to achieve short delay and fault-tolerance. (2) On-tree dynamic routing: The shared-tree approach is extended with capability of alternative path selections. If a node becomes absent from the shared tree, some predefined backup path(s) is (are) used to bypass the node and enable dynamic multicast routing to continue. The protocol requires only the routers near the faulty node to be reconfigured, thus reducing the runtime overhead as compared with global reconfiguration. The simulation data demonstrates the efficiency of our routing protocol.     

Switching supervisory control based on controller falsification and closed-loop performance inference

The paper addresses two of the basic issues of switching supervisory control (SSC): controller falsification (CF) and inference of candidate loop behaviour (ICLB). CF is approached as a statistical fault detection problem in that the currently operating controller is falsified as soon as a divergence trend is detected. This is achieved by considering a statistic (or residual) in the form of a ratio of closed-loop variables, and the falsification test is carried out by comparing at each time the ratio statistic with a threshold. It is constructively shown that the thresholds can be fixed, irrespective of the disturbance intensity, in such a way that faults are detected with probability one while probability of false alarms can be made as small as we wish. The ICLB issue is approached by the virtual reference approach. This allows one to obtain an inference of the performance of a candidate loop via a mean-square average of suitably filtered prediction errors. It is shown how a supervisory logic can be built by combining the results on CF with those on ICLB.     

配电网络重构的改进混合遗传算法

提出了一种基于改进的混合遗传算法的配电网重构算法,在算法中使用可操作开关支路的整数编号的排列顺序来表示染色体,并通过译码器的设计来映射染色体所对应的辐射状网络结构,避免了产生不可行解的情况,大大提高了算法的运算效率。同时在算法中引入了局部寻优算子,改善了算法的局部寻优性能。算例结果表明本算法是高效可行的。     

Guest editors’ introduction: Advancements and extensions of verification techniques

This special section is devoted to a selection of journal versions of papers that appeared originally in the Proceedings of the 8th International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS), which took place in Grenoble, France in April 2002 as a constituent event of the European joint conferences on Theory and Practice of Software (ETAPS). All papers are relevant to the field of systems validation. The first three papers advance and extend model-checking techniques, the fourth presents algorithms for run-time verification, and the last paper is about animation and test generation for formal system specifications.     

Data Buffering and Allocation in Mapping Generalized Template Matching on Reconfigurable Systems

Image processing algorithms for 2D digital filtering, morphologic operations, motion estimation, and template matching involve massively parallel computations that can benefit from using reconfigurable systems with massive field programmable gate array (FPGA) hardware resources. In addition, each algorithm can be considered a special case of a generalized template matching (GTM) operation. Application performance on reconfigurable computer systems is often limited by the bandwidth to host or off chip memory. This paper describes the GTM operation and characterizes the data allocation and buffering strategies for the GTM operation on reconfigurable computers. Several mechanisms that support different levels of parallelism are proposed and summarized in the paper. Finally, the implementation of an infrared automatic target recognition application on two commercial FPGA boards is used to demonstrate the various design options with different data allocation and buffering mechanisms and the pruning of the design space based on the FPGA area and memory constraints.     

Distributed Control for 3D Metamorphosis

In this paper, we define Proteo as a class of three-dimensional (3D) metamorphic robotic system capable of approximating arbitrary 3D shapes by utilizing repeated modules. Each Proteo module contains embedded sensors, actuators and a controller, and each resides in a 3D grid space. A module can move itself to one of its open neighbor sites under certain motion constraints. Distributed control for the self-reconfiguration of such robots is an interesting and challenging problem. We present a class of distributed control algorithms for the reconfiguration of Proteo robots based on the goal-ordering mechanism. Performance results are shown for experiments of these algorithms in a simulation environment, and the properties of these algorithms are analyzed.