zhq0609的专栏

因素的影响。基于 SIFT 特征提取的人脸识别隶属于局部的特征点的提取算法，这种算法目前来将在人脸图像遭受复杂环境的影响时具有将强的鲁棒性，是人脸识别的主流和发展趋势。未来的人脸识别技术会有更快更高效的算法被提出，检验一个算法的健壮性的好坏最终要的就是检测其在真实环境中的表现能力，也就是对存在噪声、光照、姿势、表情、部分遮挡、旋转、尺度变化以及一定程度的仿射变换等干扰因素影响下的鲁棒性；此外 3D 人脸识别技术也是人脸识别发展的一个重要方向，通过 3D 可变模型对人脸进行建模，摆脱二维人脸算法中的束缚，取得更优异的识别效果。 人脸识别仍旧是一项具有挑战性的任务，人脸识别不仅要考虑在比如 Yale，ORL，AR 等人脸库上的识别率，更重要的是对现实应用环境的抗干扰性，比如声、光照、姿势、表情、部分遮挡、旋转、尺度变化以及一定程度的仿射变换等

对GIS 局部放电辐射的 电磁波使用快速傅立叶 变换( F FT 和小波变换 ( 分析 , 可对不同局部放电源产生的信号进行检测区别, 了解局部放电的存在及其发展

局部放电模式识别特征量提取方法研究与特征量相关性分析

作者：friendcn 日期：2001-2-22 12:50:46 Page changes The following are the list of changes that occurred using the Struts tag library: Imports <%@ taglib uri="/WEB-INF/struts.tld" prefix="struts" %> The <%@page import? for Java has been replaced by <%@ taglib uri? for the Struts tag library. Text <struts:message key="join.title"/> The resource property file contains the text for join.title. In this example, ApplicationResources property file contains the name-value pair. This makes string review and changes for internationalization easier. Errors <form:errors/> ActionServlet or ActionForm builds the error message to display. These error messages can also be contained in the property file. ApplicationResources also provides a way of formatting the error by setting error.header and error.footer. HTML Form <form:form action="join.do" focus="email" > JSP <form> tags and attributes replace HTML <form> tags and attributes. <form action="join.jsp" name="join"> has changed to <form:form action="join.do" focus="email" >. HTML <input> tag has been replaced by <form:text/>. HTML <submit> tag has been replaced by <form:submit/>. Model -- Session state JoinForm subclasses ActionForm and contains the form data. The form data in this example is simply the e-mail address. I have added a setter and getter for the e-mail address for the framework to access. For demonstration purposes, I overwrote the validate() method and used the error tracking feature of Struts. Struts will create JoinForm and set the state information. Model -- Business logic As we discussed earlier, Action is the interface between the Controller and the actual business object. JoinAction wraps the calls to the business.jar that was originally in join.jsp. The perform() method for JoinAction is displayed in Listing 5. Listing 5. - JoinAction.perform() public ActionForward perform(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { // Extract attributes and parameters we will need JoinForm joinForm = (JoinForm) form; String email = joinForm.getEmail(); ActionErrors errors = new ActionErrors(); // store input.... try { business.db.MailingList.AddEmail(email); } catch (Exception e) { // log, print stack // display error back to user errors.add("email",new ActionError("error.mailing.db.add")); } // If any messages is required, save the specified error messages keys // into the HTTP request for use by the <struts:errors> tag. if (!errors.empty()) { saveErrors(request, errors); // return to the original form return (new ActionForward(mapping.getInput())); } // Forward control to the specified 'success' URI that is in the Action.xml return (mapping.findForward("success")); } Note: The perform() returns a class called ActionForward that tells the Controller where to go next. In this example, I am using the mapping passed in from the Controller to determine where to go. Controller I have modified the JSP file and created two new classes: one to contain form data and one to call the business package. Finally, I glue it all together with changes to the configuration file struts-config.xml. Listing 6 displays the action element I added to control the flow of joinMVC.jsp. Listing 6. Action Configuration <action path="/join" name="joinForm" type="web.mailinglist.JoinAction" scope="request" input="/joinMVC.jsp" validate="true"> <forward name="success" path="/welcome.html"/> </action> The action element describes a mapping from a request path to the corresponding Action classes that should be used to process the requests. Each request type should have a corresponding action element describing how to process the request. On a join request: joinForm is used to hold the form data. Since validate is marked true, joinForm will try to validate itself. web.mailinglist.JoinAction is the action class used to process requests for this mapping. If everything works correctly, the request will forward to welcome.jsp. If there is a business logic failure, the flow will return to joinMVC.jsp, which is the original page that made the request. Why is this? In the action element in Listing 6 is an attribute called input with a value of "/joinMVC.jsp". In my JoinAction.perform(), displayed in Listing 5, if the business logic fails, perform() returns an ActionForward using mapping.getInput() as the parameter. The getInput() in this instance is "/joinMVC.jsp". If the business logic fails, it will return to joinMVC.jsp, which is the original page that made the request. Before and after Struts As we can see from Figure 9, a lot of complexity and layers have been added. No more direct calls from the JSP file to the Service layer. Figure 9. Before and after Struts Struts pros Use of JSP tag mechanism The tag feature promotes reusable code and abstracts Java code from the JSP file. This feature allows nice integration into JSP-based development tools that allow authoring with tags. Tag library Why re-invent the wheel, or a tag library? If you cannot find something you need in the library, contribute. In addition, Struts provides a starting point if you are learning JSP tag technology. Open source You have all the advantages of open source, such as being able to see the code and having everyone else using the library reviewing the code. Many eyes make for great code review. Sample MVC implementation Struts offers some insight if you want to create your own MVC implementation. Manage the problem space Divide and conquer is a nice way of solving the problem and making the problem manageable. Of course, the sword cuts both ways. The problem is more complex and needs more management. Struts cons Youth Struts development is still in preliminary form. They are working toward releasing a version 1.0, but as with any 1.0 version, it does not provide all the bells and whistles. Change The framework is undergoing a rapid amount of change. A great deal of change has occurred between Struts 0.5 and 1.0. You may want to download the most current Struts nightly distributions, to avoid deprecated methods. In the last 6 months, I have seen the Struts library grow from 90K to over 270K. I had to modify my examples several times because of changes in Struts, and I am not going to guarantee my examples will work with the version of Struts you download. Correct level of abstraction Does Struts provide the correct level of abstraction? What is the proper level of abstraction for the page designer? That is the $64K question. Should we allow a page designer access to Java code in page development? Some frameworks like Velocity say no, and provide yet another language to learn for Web development. There is some validity to limiting Java code access in UI development. Most importantly, give a page designer a little bit of Java, and he will use a lot of Java. I saw this happen all the time in Microsoft ASP development. In ASP development, you were supposed to create COM objects and then write a little ASP script to glue it all together. Instead, the ASP developers would go crazy with ASP script. I would hear "Why wait for a COM developer to create it when I can program it directly with VBScript?" Struts helps limit the amount of Java code required in a JSP file via tag libraries. One such library is the Logic Tag, which manages conditional generation of output, but this does not prevent the UI developer from going nuts with Java code. Whatever type of framework you decide to use, you should understand the environment in which you are deploying and maintaining the framework. Of course, this task is easier said than done. Limited scope Struts is a Web-based MVC solution that is meant be implemented with HTML, JSP files, and servlets. J2EE application support Struts requires a servlet container that supports JSP 1.1 and Servlet 2.2 specifications. This alone will not solve all your install issues, unless you are using Tomcat 3.2. I have had a great deal of problems installing the library with Netscape iPlanet 6.0, which is supposedly the first J2EE-compliant application server. I recommend visiting the Struts User Mailing List archive (see Resources) when you run into problems. Complexity Separating the problem into parts introduces complexity. There is no question that some education will have to go on to understand Struts. With the constant changes occurring, this can be frustrating at times. Welcome to the Web. Where is... I could point out other issues, for instance, where are the client side validations, adaptable workflow, and dynamic strategy pattern for the controller? However, at this point, it is too easy to be a critic, and some of the issues are insignificant, or are reasonable for a 1.0 release. The way the Struts team goes at it, Struts might have these features by the time you read this article, or soon after. Future of Struts Things change rapidly in this new age of software development. In less than 5 years, I have seen things go from cgi/perl, to ISAPI/NSAPI, to ASP with VB, and now Java and J2EE. Sun is working hard to adapt changes to the JSP/servlet architecture, just as they have in the past with the Java language and API. You can obtain drafts of the new JSP 1.2 and Servlet 2.3 specifications from the Sun Web site. Additionally, a standard tag library for JSP files is appearing; see Resources for links to the specifications and the tag library. Final notes Struts solved some big problems using tags and MVC. This approach aided in code re-usability and flexibility. By separating the problem into smaller components, you will be more likely to reuse when changes do occur in the technology or problem space. Additionally, Struts enabled page designers and Java developers to focus on what they do best. Yet, the tradeoff in increased robustness implies an increase in complexity. Struts is much more complex than a simple single JSP page, but for larger systems Struts actually helps manage the complexity. Additionally, I do not want to write my own MVC implementation, just learn one. Whether you use Struts or not, reviewing the Struts framework (excuse me, library) can give you a better understanding of JSP files and servlets features, and how to combine them for your next Web project. Just as struts are essential to the structure of a wing, Struts might become an indispensable part of your next Web project.

《云计算入门指南》.pdf

操作系统考试题及计算机组成与结构考试题 (研究生入学试卷6暂缺答案) (0013)《计算机组成原理》复习思考题 一、单项选择题 1．下列（ ）属于应用软件。 　　　　① 操作系统 ② 编译系统 ③ 连接程序 ④ 文本处理 2．计算机的字长决定了（ ）。 　　　　①指令直接寻址能力 ②计算机的运算精度 　　　　③计算机的运算速度 ④计算机的高低档次 3．主板上高速缓冲存储器CACHE是设在（ ）。 　　　　①主存与CPU之间 ②主存与外存之间 　　　　③接口板上 ④CPU内部 4．进位计数制中的最大数是指（ ）。 　　①一个数允许使用的最大数码 ②一个数位允许使用的数码个数 　　③一个固定的常数值 ④数码在数据中的不同位置 5．相联存贮器是按（ ）进行寻址的存贮器。 ① 地址方式 ② 堆栈方式 ③ 内容指定方式 ④ 地址方式与堆栈方式 6．总线中地址线的作用是（ ）。。。。。。。。。。。。。

考研练习题系列 有选择填空判断应用 以后我还会陆续上传答案的数据类型是程序设计语言中的一个概念，它是一个值的集合和操作的集合。如C语言中的整型、实型、字符型等。整型值的范围（对具体机器都应有整数范围），其操作有加、减、乘、除、求余等。实际上数据类型是厂家提供给用户的已实现了的数据结构。“抽象数据类型（ADT）”指一个数学模型及定义在该模型上的一组操作。“抽象”的意义在于数据类型的数学抽象特性。抽象数据类型的定义仅取决于它的逻辑特性，而与其在计算机内部如何表示和实现无关。无论其内部结构如何变化，只要它的数学特性不变就不影响它的外部使用。抽象数据类型和数据类型实质上是一个概念。此外，抽象数据类型的范围更广，它已不再局限于机器已定义和实现的数据类型，还包括用户在设计软件系统时自行定义的数据类型。使用抽象数据类型定义的软件模块含定义、表示和实现三部分，封装在一起，对用户透明（提供接口），而不必了解实现细节。抽象数据类型的出现使程序设计不再是“艺术”，而是向“科学”迈进了一步。