基于UNIX系统的WWW服务器程序的实现

本文介绍了ＷＷＷ的通信规程和核心协议－－－ＨＴＴＰ，通过对广泛使用的ＮＣＳＡ版本的ＨＴＴＰ服务器程序的分析，使用户了解如何在ＵＮＩＸ操作系统上实现ＷＷＷ服务。     

EIKI

ＥＩＫＩ ＬＣ－ＮＢ１Ｗ分辨率 ＳＶＧＡ ８００＊６００支持ＸＧＡ光源亮度 ９００ＡＮＳＩ １６０Ｗ ＵＨＰ ３０００Ｈ重量 ３．９ｋｇＥＩＫＩ ＬＣ－８７０分辨率 ＳＶＧＡ ８００＊６００支持ＸＧＡ光源亮度 １２５０ＡＮＳＩ １６０Ｗ ＵＨＰ ３０００Ｈ重量 ６．６ｋｇEIKI     

THE CADD AND SIMULATION SYSTEM OFTHE NEW-TYPE GEAR

ＴＨＥＣＡＤＤＡＮＤＳＩＭＵＬＡＴＩＯＮＳＹＳＴＥＭＯＦＴＨＥＮＥＷ－ＴＹＰＥＧＥＡＲＨｏｎｇＨａｎｙｕ；ＧｕａｎＲｏｎｇｃｈａｎｇＴＨＥＣＡＤＤＡＮＤＳＩＭＵＬＡＴＩＯＮＳＹＳＴＥＭＯＦＴＨＥＮＥＷ－ＴＹＰＥＧＥＡＲ￥ＨｏｎｇＨａｎｙｕ；ＧｕａｎＲ...     

Constructing M-sided Patches with NURBS

ＣＯＮＳＴＲＵＣＴＩＮＧＮ－ＳＩＤＥＤＰＡＴＣＨＥＳＷＩＴＨＮＵＲＢＳＷａｎｇＬａｚｈｕ；ＺｈｕＸｉｎｘｉｏｎｇＣＯＮＳＴＲＵＣＴＩＮＧＮ－ＳＩＤＥＤＰＡＴＣＨＥＳＷＩＴＨＮＵＲＢＳ￥ＷａｎｇＬａｚｈｕ；ＺｈｕＸｉｎｘｉｏｎｇＡｂｓｔｒａｃｔＴｈｅｐ...     

网络安全问题漫谈

ＷＷＷ是Ｉｎｔｅｒｎｅｔ上的交流信息子系统,它促使了信息资源共享化,开发一个人类共有的虚拟知识库,也是信息研究开发者互相提供各种有用信息和交流思想的新途径。由于它采用了客户／服务器的软件体系结构,而 Ｗｅｂ服务器可接收来自Ｉｎｔｅｒｎｅｔ上未经坚定主机所发出的匿名申请,并迅速回应所需信息,此时恶意网络攻击者先攻击 Ｗｅｂ服务器,然后通过Ｔｅｌｎｅｔ、Ｒｌｏｇｉｎ、 ＲＳＨ、ＦＴＲ或 ＲＣＰ经该 Ｗｅｂ站点攻击网络其他端点,造成ＷＷＷ的安全威胁。 网络安全问题和ＷＷＷ的核心机制构成有很大关联。ＷＷＷ的核心机制由三大部分构成。 ＵＲＬ（ｕｎｉｖｅｒｓａｌ ｒｅｓｏｕｒｃｅ ｉｎｄｅｎｔｉｆｉｅｒ）统一资源定位法、ＨＴＴＰ协议（ｈｙｐｅｒｔｅｘｔ ｔｒａｎｓｆｅｒ　ｐｒｏｔｏｃｏｌ）超文本传输协议、 ＨＴＭＬ（ｈｙｐｅｒｔｅｘｔ　ｍａｒｋｕｐ　ｌａｎｇｕａｇｅ）超文本标记语言,其中ＵＲＬ使用的协议可为ＨＴＴＰ超文本传输协议、ＦＴＰ文件传输、ＭＡＴＴＯ发电子邮件、ＴＥ ＬＮ ＥＴ远程登录、ＷＡＩＳ广域信息服务、ＮＥＷＳ新闻组等。     

威胁与防御

随着Ｉｎｔｅｒｎｅｔ的发展,客户／服务器结构逐渐向浏览器／服务器结构迁移,因此Ｗｅｂ服务在很短时间内也成为Ｉｎｔｅｒｎｅｔ上的主要服务。Ｗｅｂ文本发布具有简洁、生动、形象等特点,所以,无论是单位和个人,都越来越倾向于用Ｗｅｂ来发布自己的信息。Ｗｅｂ服务基于超文本传输协议,即ＨＴＴＰ协议。目前,ＨＴＴＰ协议共有三个版本,分别为ＨＴＴＰ０．９、ＨＴＴＰ１．０和ＨＴＴＰ１．１。其中ＨＴＴＰ１．０为大多数服务器和浏览器所使用,是一个面向连接的无状态的协议,在ＴＣＰ的端口８０上进行信息的传输。大多数Ｗｅ…     

一种用 JAVA 服务器实现的 WEB 数据库

从Ｊａｖａ的网络通信技术和ＷＷＷ的ＨＴＴＰ协议的应用以及ＪＤＢＣ技术入手，介绍一种用Ｊａｖａ服务器实现的ＷＥＢ数据库     

任意长度GFT的W变换算法

任意长度ＧＦＴ的Ｗ变换算法付彬（湖南大学数学系）曾泳泓（国防科技大学七系）Ｗ－ＴＲＡＮＳＦＯＲＭＡＬＧＯＲＩＴＨＭＯＦＱＦＴＷＩＴＨＡＲＢＩＴＲＡＲＹＬＥＮＧＴＨ￥ＦｕＢｉｎ（ＨｕｎａｎＵｎｉｖｅｒｓｉｔｙ，Ｃｈａｎｇｓｈａ，Ｈｕａｎａ）ＺｅｎｇＹｏ...     

实现文件下载的两种方法

超文本传输协议（ＨＴＴＰ． ＨｙｐｅｒＴｅｘｔＴｒａｎｓｆｅｒ Ｐｒｏｔｏｃｏｌ）和文件传输协议（ＦＴＰ, Ｆｉｌｅ Ｔｒａｎｓｆｅｒ Ｐｒｏｔｏｃｏｌ）是两种使用得最为广泛的因特网协议。 ＨＴＴＰ 协议的主要作用就是对某个万维网（ＷＷＷ）资源服务器的文件进行访问,包括对该服务器上指定文件的浏览、下载、运行等,也就是说,通过ＨＴＴＰ我们可以访问因特网上的所有万维网资源。 ＦＴＰ协议是从因特网上获取文件的最常用协议,通过该协议用户可以很方便地连接到远程服务器上,查看远程服务器上的文件内容,同时还可以把所需…     

正确使用PING工具测试网络连通性

ＰＩＮＧ 是一个验证网络上两台计算机之间连通性的分析工具,是Ｗｉｎｄｏｗｓ９５／９８／ＮＴ中集成的一个ＴＣＰ／ＩＰ协议探测器,它发送网间控制报文协议（ＩＣＭＰ）回应请求报文到一个远程ＩＰ地址,然后接收返回的应答报文,以统计响应两者所经历的时间间隔,从而分析网络的整体特性。１正确使用 ＰＩＮＧ工具 一般来讲,ＰＩＮＧ 是检测收发ＩＰ报文能力的一个指示器,如果能够ＰＩＮＧ一个主机,那么就也可以建立一个ＦＴＰ或ＨＴＴＰ连接。在Ｗｉｎｄｏｗｓ９５／９８／ＮＴ环境中,可以通过切换到ＭＳ－ＤＯＳ的提示符下运行Ｐ…     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate