共查询到19条相似文献,搜索用时 171 毫秒
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计算机应用系统中的菜单子系统及操作权限控制子系统在PB中的设计与实现 总被引:1,自引:1,他引:0
王国军 《计算机工程与应用》2001,37(15):173-176
菜单子系统直接影响到计算机应用系统的易使用性及最终用户的可接受性;操作权限管理与控制是绝大多数计算机应用系统中的一个子系统,在保证整个系统正常、安全运行中起着至关重要的作用。该文介绍计算机应用系统中菜单子系统和操作权限控制子系统在PB中的设计与实现。 相似文献
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任伟 《电脑编程技巧与维护》2006,(12):5-7
完整的数据库应用系统应该有系统登录和权限控制功能,系统管理员可以维护操作员管理模块,对操作员帐号、密码及权限进行设置。在实际应用开发设计中,根据应用系统的使用要求有不同级别的权限控制,可以有应用极(针对系统中不同子系统)、模块级(针对功能菜单模块)、数据操作级(针对数据编辑)等设置。常用的是模块级权限控制,其功能是分配给操作员可操作的功能模块,下面介绍用Delphi实现应用菜单的权限设置。 相似文献
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韩利娟 《计算机光盘软件与应用》2013,(5)
权限管理是教务管理系统中最基础,也是重要的一个子系统。本文采用SSH框架进行设计,遵循MVC设计模式,将授予不同身份用户不同的权限,这样以来,使得系统的安全性更强,操作更简便。 相似文献
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在多用户应用系统中,用户权限控制机制是系统运行机制的重要组成部分,尤其对于企业级的MIS,由于用户在企业管理中所承担的角色不同,权限控制成为实现分工负责、确保系统安全运行的重要技术手段。 相似文献
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内存管理是计算机编程最为基本的领域之一。在很多脚本语言中,不必担心内存是如何管理的,这并不能使得内存管理的重号性有一点点降低。对实际编程来说,理解内存管理器的能力与局限性至关重要。在大部分系统语言中,比如C和C++,必须进行内存管理。本文将介绍C/C++内存管理的基本技术及应用。C++中涉及到的内存的管理问题可以归结为两方面:正确地得到它和有效地使用它。“正确地得到”的意思是正确地调用内存分配和释放程序;而“有效地使用”指写特定版本的内存分配和释放程序。 相似文献
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V. A. Tsarev 《Automation and Remote Control》2011,72(1):196-207
The problem of development and customization of optoelectronic land traffic flow monitoring systems with account taken of
specified operational conditions is examined. The methodology for automated design of algorithmic support for the main subsystem
of the mentioned systems, namely, the one for vehicle registration number recognition is suggested. 相似文献
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复杂工业过程具有模型维数高、多时间尺度耦合、动态不确定性等特点,其运行优化控制(Operational optimal control, OOC)一直是控制领域的研究难点与热点.本文聚焦一类由多个快变且互联的设备单元与慢变且模型未知的运行过程串联组成的工业过程,提出一种数据和模型混合驱动的非串级双速率组合分散运行优化控制方法.该方法通过奇异摄动理论,将非串级双速率运行优化问题描述为异步采样的慢子系统最优设定值跟踪和快子系统最优调节控制.利用工业运行数据,采用不依赖系统动态的Q-学习算法设计慢子系统最优跟踪策略,克服运行过程模型难以建立的情形;针对快子系统,设计基于模型的分散次优控制策略,并给出收敛因子的下界,解决设备层互联项对系统稳定性的影响.通过浮选过程仿真实验验证了所提控制方法的有效性. 相似文献
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Due to its systems control orientation, the theory of multilevel hierarchical control developed by Mesarovic and others appears especially promising for identification and modeling of large scale systems consisting of relatively independent subsystems with strong and weak intersystem coupling.Standard techniques of optimum systems control and estimation theory may be used to resolve system problems described in this format. Determination of system structure and identification of system parameters form an inherent part of this procedure.To achieve advantages by hierarchical system concepts, it is necessary to decompose a large scale system into a number of smaller parts in such a manner that individual subsystem estimation, identification and control is feasible and to coordinate the subsystems in order to obtain the overall system goal. While decomposition is in theory easy, in practice it must be accomplished such that subsystem structure preserves constraints, information structures and acceptable authority structures. The success of coordination will thus, in practice, be affected by the particular system decomposition chosen.This paper presents the results of an investigation of system identification, using the maximum a posteriori criterion, of system parameters within a hierarchical structure. Examples demonstrate the use of the system identification algorithms. 相似文献
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A multilevel feedback control scheme is proposed for optimization of large-scale systems composed of a number of (not necessarily weakly coupled) subsystems. Local controllers are used to optimize each subsystem, ignoring the interconnections. Then, a global controller may be applied to minimize the effect of interconnections and improve the performance of the overall system. At the cost of suboptimal performance, this optimization strategy ensures invariance of suboptimality and stability of the systems under structural perturbations whereby subsystems are disconnected and again connected during operation. 相似文献
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杨旺明 《计算机与数字工程》2014,(3):482-485
在Web系统开发中,由于系统资源的差异性和对权限管理要求的复杂性导致产生一些问题,如同一个系统中不同的子业务设置不同的权限,从而需要对不同的子业务模块编写权限控制代码,而这些代码存在着重复设计冗余编写以致降低了Web系统的开发效率.针对上述问题,在ASP.net中已有的基于角色的访问控制部分上,结合RBAC授权模型进行系统扩展,设计并实现了一个可以在中小型Web应用系统中通用的权限管理系统子模块.该模块采用三层结构,实现了权限控制和业务的分离,可以很方便地在其他Web系统中使用. 相似文献
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Apostolos P. Leros 《International journal of control》2013,86(4):1377-1399
This paper presents as its main result a new control approach of regulating linear large-scale systems (LSS). This approach is based on the concept of ‘partial decentralization’. It differs from other LSS control schemes in that, based on direct arguments, it clearly identifies suboptimality due to decomposition of the LSS linear regulator problem into smaller subproblems, it takes advantage of the LSS structure without system model alteration, and it is based only on the decomposition of the objective function. The resulting controller is feedback and non-iterative in nature with the features of utilizing with complete weighting in the objective function the subsystem interconnections, parallel processing for on-line implementation, and structure flexibility in the sense that the addition and/or deletion of a subsystem does not require the design of the control law of the overall LSS from the beginning again. The stability of the resulting closed-loop LSS is also addressed and a numerical example illustrating the applicability of this new controller is presented. 相似文献