分布式系统

A high order finite element model of a duralumin flexible beam with distributed piezoelectric sensors and actuators was presented in this paper. The beam equation was developed incorporating the stiffness, mass and electromechanical coupling effects of the piezoelectric apparatuses.

本文针对一套表面粘贴有分布式压电传感器和致动器的LY12智能材料柔性臂系统，在对系统组成进行分析的基础上，建立了柔性臂实验系统的有限元模型，并采用自由度凝聚法对该模型进行了降阶处理，以方便控制器设计。

The CNC dressing system based 32-bit micro-computer, and the DNC dressing system developed in this paper plays an important role in the practical production, and it is helpful to study the gear cutter profile modification system deeply.

本文完成的基于32位工业控制机的砂轮修形CNC系统，以及分布式砂轮修形DNC系统，已获得推广应用，这对齿轮刀具修形系统的进一步深入研究具有促进作用。

The configuration and development of simulation computer system, especially the special purpose centralized computer system for the hardware-inthe-loop simulation and general purpose distributed computer system for the operator-in-the-loop simulation, are reviewed.

回顾了仿真计算机系统的结构和发展，特别是面向半实物仿真应用的专用集中式计算机系统和面向人在回路仿真应用的通用分布式计算机系统的结构和发展。

The method of distributed control system composed by PLC technology in glasshouse control is introduced in this paper.

讨论了在温室控制中引入PLC技术构成分布式控制系统的方法，详细介绍了系统的特点、组成、软硬件设计、实时动态监控系统及通信问题。

The author has tried an introductive design to form the Distributed Educational Resource Integration System, and mark out its logical structure. Then I also attempt to define the functions of its sub-systems, and to discuss the problems during the developing of the system (such as the selection of the standards, the balance between efficiency and functions, etc.), further more, I have given the countermeasures accordingly.

笔者对分布式教育资源整合系统的技术实现进行了初步的设计，规划了系统的逻辑结构，并对系统的功能划分，构建过程中遇到的主要技术难题（如标准的取舍、效率与功能的平衡、安全问题等）进行了探讨并提出了相应的对策。

However, the performance of conventional network file system or distributed file system is limited by the low usage of the file system cache and can not meet the application demand.

现有的网络文件系统或分布式文件系统已无法满足应用需求，因此需要对进一步提高机群文件系统性能的技术进行深入研究。

In this system, the combined orientation model of DTWADGPS is established using the WADGPS, odograph, speedometer and roscope, etc. And the information of the multi-sensor is processed using the method of data fusion, which is used to resolve the accuracy and blind area problems of train position Combining the technology of GIS and GSM-R and the Expert System, the system of intellectualized train dispatch and management is established based on train positions and velocities acquired accurately.

系统采用WADGPS、里程表、车速仪、陀螺仪等构建分布式逆向WADGPS组合定位模型并对多传感器信息进行融合处理，解决列车定位的精度和盲区问题；在精确获取列车位置和速度的基础上，结合GIS和GSM-R技术和专家系统构建列车智能调度管理系统。

The architecture of Client/Server based on transaction middleware is a typical kind of the distributed On-line Transaction Processing, becoming a major platform of enterprise information system, which offers communication of striding platform, loading balance, fault-tolerant and resumable ability, and strengthens a new generation middleware in common with 3-layer architecture provided with the strong security, excellent management and high availability in common. Numerous distributed system, different database and different network environment are closely linked up among an enterprise, offering the function of mutual operation on application layer.

基于交易中间件的C／S结构是一种典型的分布式事务处理系统，成为构筑企业信息系统的主流平台，它提供了强大的跨平台通讯、负载平衡、容错及其故障恢复能力，并在这个基础上进一步强化了安全性、可管理性和高可用性的新一代通用型三层结构平台的中间件，把企业中众多的异构系统、异构数据库、不同网络环境紧密的联系起来，并在应用层提供了互操作性的功能。

After studying the MAC protocol of Ad hoc network and by modifying the Wireless Token Ring Protocol, a new uncontested Distributed Parallel Wireless Polling Access Protocol that can provide MAC QoS guarantees for Ad hoc network is presented, and the mathematical model is established by the embedded Markov chain theory and the probability generating function method. Based on it, the mean value of queue length and message waiting time are explicitly obtained.

摘要该文对Ad hoc网络的MAC层协议进行了研究，通过对无线令牌环协议进行改进，提出了一种新的具有QoS保障的无竞争的分布式并行无线轮询访问协议，并采用嵌入Markov链和概率母函数的分析方法，用限定服务规则进行了系统建模，在系统模型的基础上得到了系统的平均排队队长以及平均等待时间的解析结果。

The main features of the system are: the communications line is not only used for data transmission but also responsible for the system control and management; only one analogue to digital converter is needed for the whole system; a digital trimmer which is analogous to the adjustable resister in function is installed to each sub—system.

本文所进行的数字型条干均匀度测试仪的系统设计，采用了多微处理器的分布式并行结构，提出了一种数字信号的总线结构，采取了数据预处理和数字微调等措施，其主要特点为：半双工异步通信线不但用于数据传输，而且还负责系统的控制和管理；整个系统只需一路模数转换器；各子系统均设有数字微调装置，其功能类似于模拟电路中的电位器，可独立进行参数调整。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。