基于AJAX UpdatePanel无刷新多级联查询的应用研究

笔者通过软件测试实验详细分析ASP.NET的UpdatePanel控件在处理多级联动查询事务中的具体应用,通过实验测试效果对比,表明其在特定场合具有更强的细节实现能力和用户体验。ScriptManager和UpdatePanel控件联合使用可以实现页面异步局部更新的效果。其中的UpdatePanel就是设置页面中异步局部更新区域,它必须依赖于criptManager,因为ScriptManger控件提供了客户端脚本生成与管理UpdatePanel的功能。     

ASP.NET AJAX技术在Web开发中的应用研究

介绍ASP.NETAJAX的体系结构,详述如何使用ASP.NET AJAX框架的ScriptManager控件调用Web服务、UpdatePanel控件实现Web页面的局部更新、UpdateProgress控件实现页面刷新的过程信息,以及使用Timer控件实现定时刷新.介绍ASP.NET AJAX的扩展控件包MAX Control Toolkit的安装和使用方法.     

Visual C#创建用户控件

在使用Visual C#开发应用程序的过程中,经常会遇到系统提供的控件不能满足用户需求的情况,这时需要创建用户控件实现具有特殊功能的控件。Visual C#允许用户定义三种类型的用户控件：复合控件、扩展控件和自定义控件,通过实例解析了Visual C#中如何实现这三种类型的控件。     

DELPHI编程技巧点滴

一、DELPHI IDE环境的一个使用技巧 DELPHI的控件可以分为容器控件和非容器控件两类。容器控件是用来放置其他非容器控件的,例如Panel就是很常用的容器控件,可以在上面放置Button、Label等控件。同样,FORM也是容器类的控件。 如果一个放置在容器控件上的控件,其aligned属性被设置成alClient,那想要选中它的容器控件就比较困难。比如,在FORM上放一个IMAGE控件,设置IMAGE控件的aligned属性为alClient,此时要选取FORM,似乎只有靠在对     

C#.NET中控件数组的实现

在VB中使用控件数组非常灵活,同样在C#中也可以实现控件数组的功能.从三个方面说明C#如何完成控件数组的功能,即对多个控件赋值,多个控件使用同一个事件处理程序,在运行时动态添加或者删除控件.     

用VB5.0编制一个ActiveX控件

使用控件,是VB实现可视化编程和代码复用的重要手段,经历了VBX控件和OCX控件后,VB5.0不但升级为更先进的ActiveX控件,而且还提供了开发ActiveX控件的强大功能。开发者可以通过组合现有的控件来派生新的控件,同时可以继承或新增一些属性、方法、甚至事件。新建的控件也可加入数据绑定支持、自动注册、属性页、Internet特性等功能。     

VB中插入动画的几种方法

介绍了在Windows XP操作系统下,如何利用VB 6.0中的Animation控件、MCI控件、Anigif控件、SwFlash控件以及WebBrowser控件来插入无声和有声的AVI视频动画、GIF动画及FLASH动画的方法.     

VC++静态控件子类化在窗口预览中的应用

为实现某图像控件窗口位置和尺寸的预览功能,在预览对话框中用静态控件窗口代表图像控件窗口,采用静态控件子类化的方法,增加了静态控件响应鼠标拖动和鼠标滚轮缩放的功能,用户可通过对静态控件窗口拖动和缩放,来完成对图像控件窗口的设置.     

Java中双向控件的使用、制作及布局*

介绍了一种国际化控件--双向控件的使用、制作和布局方法,并介绍了如何设置控件的方向,设计控件的结构和布局控件的原理,以及在此过程中可能遇到的问题和解决方法.     

树形控件和列表控件在"新闻稿处理编程"中的应用

树形控件和列表控件都是基于对话框使用的控件.列表控件显示一个项目列表供用户浏览和选择,而树形控件用来以树形格式显示有层次的信息.本文以基于对话框的新闻稿处理程序为例,编写了自己的列表控件类和树形控件类,并说明了它们在对话框编程中的应用.     

网络环境下不敏感系统的分布式区域预测控制方法

针对二分图网络结构下的不敏感系统的可控性比较差的问题,本文提出了带有区域控制的分布式模型预测控制方法.该方法首先利用分支定界法对分布式控制系统结构进行最优设计;然后,结合区域控制提高控制系统的动态性能指标;最后,依据回路之间的关联性的强弱选择每个回路的控制方式(精确控制或区域控制).仿真结果显示带有区域控制的分布式预测控制系统的调节时间比没有带区域控制的分布式控制系统明显缩短;同时,通过对回路控制方式的选择增加了精确控制的智能体数量.仿真结果证明了利用分布式区域预测控制方法可以提高系统的容错性,通过对系统的可控性和关联性进行分析,可以在精确控制和区域控制之间寻找到最优组合,从而达到快速精确的控制效果.     

Robust and adaptive control: fidelity or an open relationship?

Robust and adaptive control are essentially meant to solve the same control problem. Given an uncertain LTI model set with the assumption that the controlled plant slowly drifts or occasionally jumps in the allowed model set, find a controller that satisfies the given servo and disturbance rejection specifications. Specifications on the transient response to a sudden plant change or “plant jump” are easily incorporated into the robust control problem, and if a solution is found, the robust control system does indeed exhibit satisfactory transients to plant jumps. The reason to use adaptive control is its ability, when the plant does not jump, to maintain the given specifications with a lower-gain control action (or to achieve tighter specifications), and also to solve the control problem for a larger uncertainty set than a robust controller. Certainly equivalence-based adaptive controllers, however, often exhibit insufficient robustness and unsatisfactory transients to plant jumps. It is therefore suggested in this paper that adaptive control always be built on top of a robust controller in order to marry the advantages of robust and adaptive control. The concept is called adaptive robust control. It may be compared with gain scheduling, two-time scale adaptive control, intermittent adaptive control, repeated auto-tuning, or switched adaptive control, with the important difference that the control is switched between robust controllers that are based on plant uncertainty sets that take into account not only the currently estimated plant model set but also the possible jumps and drifts that may occur until the earliest next time the controller can be updated.     

Extension and experimental evaluation of an event-based state-feedback approach

Event-based control aims at reducing the traffic load of the communication network used to implement feedback control. The communication is invoked only if an event indicates that the control error exceeds a certain threshold. This paper extends a state-feedback approach to event-based control published recently and proves that the extended control loop asymptotically reaches the set-point for arbitrary constant disturbances. This control method is applied to a thermofluid process to illustrate the main characteristics of event-based control and to evaluate the closed-loop performance. Experiments with a pilot plant show that the event-based control scheme is robust against severe model uncertainties.     

Qualitative robust fuzzy control with applications to 1992 ACCbenchmark

Robust control has long been the purview of quantitative linear control techniques, while qualitative symbolic control has been deemed more suitable to obtaining complex control objectives that require only low-output precision. The intelligent techniques of fuzzy control have, however, shown promise in obtaining results comparable to those obtained from H_∞ and H₂ robust control techniques. Often though, these fuzzy control techniques ignore the original intent of fuzzy logic: implementation of symbolic linguistic control laws based on qualitative models of the plant and control behaviors. We show that robust control objectives, even for simple plants, can be achieved by first developing qualitative behaviors that stabilize the plant and then superimposing tracking behaviors that achieve control objectives. Specifically, by superimposing qualitative stability and tracking behaviors, we can achieve robustness and tracking stability comparable to the best published linear compensators for the 1992 ACC robust control benchmark     

一种智能交通信号控制机的设计与实现*

该系统采用了“绿冲突”和备用方案的容错控制方式。即使主控部件出现故障,信号机仍可以按备选方案工作。为了便于与上位控制机连接,信号机提供了多种通信方式和“线控”功能。基于车流量检测,提出了信号机的智能控制方案。实际应用结果表明,新型的智能交通信号机系统性能稳定可靠,功能较强,便于实现“绿波带”控制和交通网络协调控制。     

无刷直流电动机积分反演模糊滑模控制

针对普通的无刷直流电动机控制策略受电动机本身因素影响,难以达到理想效果的问题,介绍了一种积分反演自适应滑模变结构控制和模糊控制相结合的控制器。该控制器在滑模面中加入积分项,实现了对速度信号的无静差跟踪,提高了系统的稳态精度;用模糊控制器来解决切换控制增益设定只能靠经验的问题;采用模糊控制算法对不确定性进行估计,有效地减小了滑模控制方法带来的抖振;为了进一步提高控制性能,重新设计了趋近律。仿真结果表明,该控制器能够大幅提升无刷直流电动机控制系统的性能。     

模糊控制和传统PID控制的仿真研究

本文运用模糊控制与PID控制分别对同一受控对象进行控制。通过MATULB仿真。表明了模糊控制与传统的PID控制相比明显地改善了控制系统的动态性能。     

Can local NURBS refinement be achieved by modifying only the user interface?

NURBS patches have a serious restriction: they are constrained to a strict rectangular topology. This means that a request to insert a single new control point will cause a row of control points to appear across the NURBS patch, a global refinement of control. We investigate a method that can hide unwanted control points from the user so that the user’s interaction is with local, rather than global, refinement. Our method requires only straightforward modification of the user interface and the data structures that represent the control mesh, making it simpler than alternatives that use hierarchical or T-constructions. Our results show that our method is effective in many cases but has limitations where inserting a single new control point in certain cases will still cause a cascade of new control points to appear across the NURBS patch.     

脉冲燃烧加热炉炉温模糊控制策略

为解决加热炉燃烧过程及传热机理极为复杂、建模困难、传统的控制方法难以实现对其炉温及加热过程精确有效控制的问题.文中将模糊控制理论与脉冲燃烧控制技术相结合,提出一种脉冲燃烧加热炉炉温完全模糊控制策略.实际应用表明,这种控制方法加热均匀、炉温响应速度快、超调量小、稳态精度高,达到了良好的控制效果.     

Control of a class of patterned systems

Engineering systems are often architected to consist of a number of interconnected parts that interact in distinct patterns. Because most control design methods only provide general, unpatterned control laws, a compelling open question is how to synthesise distributed control laws that adhere to a system's interconnection pattern. This paper addresses patterned control synthesis for systems with interconnection patterns. The pattern is encoded algebraically through commuting relationships of the system's state space matrices. We show that several classic control problems are amenable to a patterned synthesis. Moreover, we show that these patterned control problems have the same solvability conditions as their unpatterned counterparts. That is, a patterned control law can be found whenever any control law can be found. Our findings suggest that patterned systems naturally admit patterned controllers.