首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
通过多个角度论述了PB(PowerBuilder)中客户端应用程序与服务器端数据库的连接方法以及这些方法所存在的问题.为解决这些问题,提出了一种在客户端应用程序中动态连接数据库的实现方法.  相似文献   

2.
本文就长沙卷烟厂弱电线路计算机网络信息系统的开发背景进行了介绍,就该系统中的Intranet站点的实现、Web服务器和数据库服务器的配置方法、对SQL Server访问的一般步骤和方法、信息点基本内容查询与统计及图内信息查询等问题进行了讨论,并提出了解决这些问题的实现方案.  相似文献   

3.
稳定性和可扩展性是PKI系统要解决的重要问题.先进的Apache2.0框架可以为解决这些问题提供底层支持.本文介绍了一种基于Apache框架的PKI实现方法.通过对Apache过滤器机制、模块设计方法和Hooks注册机制的使用.可以设计和构建配置灵活的高性能PKI业务服务器.  相似文献   

4.
针对城市水环境仿真要解决的重要问题是对城市内河流的水量状态与水质状态的描述,并枚举各种治理措施对水环境的影响.提出了在兼顾景观表现和实时显示速度的前提下根据真实地貌生成逼真的3D模型的方法,动态水的表现方法,汉字显示的实现方法,以及使用TCP/IP协议实现接收网络仿真数据的方法.利用以上提出的这些方法,实现了动态水的生成、水质变化、水量变化、污染物的表现,并且以显示三维物体的方式实现了二维汉字的显示.这些方法已经成功地运用到了城市水环境仿真中,并取得了很好的效果.  相似文献   

5.
本文讨论了用TMS 320实现数字控制系统的几个具体问题,并着重研究由于定点运算和有限字长效应引起的量化误差、舍入和溢出,以及对这些问题的处理方法.  相似文献   

6.
介绍工程质量监督管理系统的设计方法和实现技术.主要论述设计中遇到的技术问题以及解决这些问题过程中用到的关键技术.  相似文献   

7.
本文讨论了将VAX-780型机上用FORTRAN77编写的应用程序向PDP-11/23~ 机移植中的几个问题:程序过长问题、数组过大问题以及文本限制问题.提出了解决这些问题的方法以及处理步骤.采用这些方法可以根据程序中带来的必要信息方便地实现移植任务.用以上方法移植的国际通用地震模式识别程序包已经在PDP-11/23~ 上正常运行.  相似文献   

8.
基于.NET平台的Web系统的构建和实现   总被引:8,自引:2,他引:8  
针对当今基于.NET平台开发Web系统的主流,为了更有效的发挥.NET平台的优势,提出了在.NET框架下系统结构设计和系统开发过程中应该注意的一些问题,分析了这些问题的原因,并提出了一个可重用的系统框架和一些优化的方法从而实现高效的Web系统和提高系统的整体性能.并结合实际的开发讲述了这些方法的具体的实施过程.通过实际的应用可以证明,提出的系统框架和优化方法是有效的.  相似文献   

9.
ASP.NET页面间传值综述   总被引:1,自引:0,他引:1       下载免费PDF全文
范明虎  樊红 《计算机工程》2009,35(22):88-90
对ASP.NET中各种页面间传值方法进行综述,阐述实现这些方法所必需的对象的概念、作用和特点,讨论这些方法的优缺点,通过实例代码给出这些方法的基本应用,并从生命周期、应用范围、可传递的数据类型和数据量4个方面对这些方法进行比较和分析。介绍了实现这些方法时常用的2种页面重定向方法。  相似文献   

10.
机械机电行业中大量使用设计软件制作的工程图纸,如何从这些图纸中有效和快速的获取其中的明细表信息是一个关键环节.本文针对目前明细表信息提取过程繁琐、效率不高的问题,通过对明细表信息提取方法的阐述,实现了从设计软件图纸中简洁、快速的读取信息的目标.在此基础上还可以把这些信息集成到一个软件中,以便实现和其他软件系统的集成.  相似文献   

11.
Distributed control of spatially invariant systems   总被引:2,自引:0,他引:2  
We consider distributed parameter systems where the underlying dynamics are spatially invariant, and where the controls and measurements are spatially distributed. These systems arise in many applications such as the control of vehicular platoons, flow control, microelectromechanical systems (MEMS), smart structures, and systems described by partial differential equations with constant coefficients and distributed controls and measurements. For fully actuated distributed control problems involving quadratic criteria such as linear quadratic regulator (LQR), H2 and H, optimal controllers can be obtained by solving a parameterized family of standard finite-dimensional problems. We show that optimal controllers have an inherent degree of decentralization, and this provides a practical distributed controller architecture. We also prove a general result that applies to partially distributed control and a variety of performance criteria, stating that optimal controllers inherit the spatial invariance structure of the plant. Connections of this work to that on systems over rings, and systems with dynamical symmetries are discussed  相似文献   

12.
Coordination Algorithm for Distributed Testing   总被引:4,自引:0,他引:4  
With the emergence of new models, architectures and middleware such as ODP, TINA and CORBA, for developing open distributed systems, testing technology requires adaptation for use within conformance assessment in such systems. All these frameworks are object-based and aim at creating open distributed environments supporting interworking, interoperability, and portability, in spite of heterogeneity and autonomy of the related systems. In this context, an open distributed system may be viewed as a system providing standardized distributed interfaces for interacting with other systems. Conformance of such a system can be assessed by attaching a related tester at each provided interface. However, many problems of controllability and observability influencing fault detection during the testing process, arise if there is no coordination between the testers. In this paper, we show how to cope with these problems by using test coordination procedures in a distributed testing architecture.  相似文献   

13.
Modeling distributed computer systems is known to be a challenging enterprise. Typically, distributed systems are comprised of large numbers of components whose coordination may require complex interactions. Modeling such systems more often than not leads to the nominal intractability of the resulting state space. Various formal methods have been proposed to address the modeling of coordination among distributed systems components. For the most part, however, these methods do not support formal verification mechanisms. By way of contrast, the L-automata/L-processes model supports formal verification mechanisms which in many examples can successfully circumvent state space explosion problems, and allow verification proofs to be extended to an arbitrary number of components. After reviewing L-automata/L-processes formalisms, we present here the formal specification of a fault-tolerant algorithm for a distributed computer system. We also expose the L-automata/L-processes verification of the distributed system, demonstrating how various techniques such as homomorphic reduction, induction, and linearization, can be used to overcome various problems which surface as one models large, complex systems.  相似文献   

14.
Fault Management in Distributed Systems: A Policy-Driven Approach   总被引:1,自引:0,他引:1  
Managing the availability and performance of a distributed system involves monitoring the behavior of the system, identifying system problems, and correcting those problems. Each of these tasks requires some expertise, such as an understanding of the mechanics of the underlying system components. As the size and complexity of these systems increases, and the number of distributed applications executing on these systems increases, managing the availability and performance of distributed systems becomes more difficult. Little research has focused on embedding systems management expertise into a management application for a distributed system. In this paper we describe a rule-based management application for a commercially available distributed computing environment that is capable of monitoring the distributed system, detecting system service-related performance and availability problems, and generating corrective actions to correct the problems.  相似文献   

15.
一种基于分布对象技术的Agent计算框架   总被引:29,自引:0,他引:29  
随着CORBA等分布计算技术的发展,分布式应用开始关注系统的可靠性,可用性,开放性,计算资源共享与可重用等问题。面向Agent的分布计算技术是解决上述问题的有效手段。文中基于面向Agent的计算观点,论述了分布式应用及其内部分布对象之间的关系,并针对系统可靠性以及可用性的需求,在CORBA平台上实现了一个Agent框架,用于构造面向Agnet的分布式应用。  相似文献   

16.
This article considers the distributed robust control problems of uncertain linear multi-agent systems with undirected communication topologies. It is assumed that the agents have identical nominal dynamics while subject to different norm-bounded parameter uncertainties, leading to weakly heterogeneous multi-agent systems. Distributed controllers are designed for both continuous- and discrete-time multi-agent systems, based on the relative states of neighbouring agents and a subset of absolute states of the agents. It is shown for both the continuous- and discrete-time cases that the distributed robust control problems under such controllers in the sense of quadratic stability are equivalent to the H control problems of a set of decoupled linear systems having the same dimensions as a single agent. A two-step algorithm is presented to construct the distributed controller for the continuous-time case, which does not involve any conservatism and meanwhile decouples the feedback gain design from the communication topology. Furthermore, a sufficient existence condition in terms of linear matrix inequalities is derived for the distributed discrete-time controller. Finally, the distributed robust H control problems of uncertain linear multi-agent systems subject to external disturbances are discussed.  相似文献   

17.
一种基于Agent的自适应的分布式入侵检测系统   总被引:4,自引:0,他引:4  
针对传统分布式入侵检测系统组件之间依赖程度大、系统不够健壮且入侵检测系统自身结构固定不能适应入侵的变化的问题,提出了一种基于Agent的自适应的分布式入侵检测系统(简称AAADIDS).AAADIDS采用Agent概念重新构造系统的组件,改进了分布式入侵检测系统由于高层节点单一无冗余而产生的可靠性差的缺陷,从构造上克服了分布式入侵检测系统的脆弱性.同时,AAADIDS系统采用智能技术构建了自适应的入侵检测系统模型,增加了系统应对入侵行为变化的智能性.AAADIDS系统相对于传统的分布式入侵检测系统有效地提高了系统自身的可靠性和针对外界变化的适应能力.  相似文献   

18.
Self-Adaptation Using Multiagent Systems   总被引:1,自引:0,他引:1  
Modern distributed software systems involve dynamic operating conditions that pose engineering challenges to traditional offline design. Multiagent systems engineering can solve some of these problems by offering self-adaptive features such as loose coupling, context sensitivity, and robustness to failure. The authors describe the tradeoffs in multiagent systems and lessons learned in their implementation but propose them as a critical advantage as distributed systems continue to evolve.  相似文献   

19.
Parallel distributed algorithms are presented for adding and deleting edges in a directed graph without creating a cycle. Such algorithms are useful for a variety of problems in distributed systems such as preventing deadlock or ordering priorities. The algorithms operate in a realistic asynchronous computer network environment in which there are numerous possible interactions among overlapping instances of the algorithms.  相似文献   

20.
针对在分布式系统中的层次式失效检测方法的检测准确性和检测效率的问题,在层次式失效检测机制的对象级、进程级和主机级的层次思想指导下,基于Chen预测算法提出了一种分布式系统中的层次式失效检测的改进算法。考虑到传统的分布式系统中层次式失效检侧方法的单点失效问题、检测时延等因素,在分层时把局域网的检测消息限制在组内,并且使组内的节点承担不同组间的检测。改进算法实现时增设一个信任度变量和修正比例因子,采用向网络中加负载的方式模拟大规模网络的复杂情况以增加网络延迟,完成该算法的实验验证。实验结果表明,改进算法能够提高失效检测的准确性和检测效率,降低误判率,该研究成果也为失效检测方法的进一步优化提供了研究依据.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号