结构体对象的赋值运算方法研究

随着计算机技术的飞速发展,软件的覆盖面越来越广,软件质量的保证成为了一个越来越重要的环节。结构体在程序设计语音中被广泛使用,在静态代码检测的时,对结构体变量进行区间运算的时候不能给出其明确的区间信息,会对其相关运算的判断精度造成影响,本文介绍了一种对结构体赋值运算的区间计算方法。首先,从抽象语法树中识别结构体变量节点,其次为他们建立抽象内存模型,再次根据控制流图节点在其进行赋值运算的时候对它的子成员变量进行运算。     

UML在P2P文件下载软件开发中的应用

P2P作为一种基于互联网环境的新的应用型技术，已经得到越来越多的关注，也应用在一些产品中当中。UML作为一个通用的可视化建模语言，在协议和应用方面也不断在完善。文中试以开发一个集中目录式P2P文件下载软件为背景，使用UML进行需求分析，设计和构造，将P2P的技术应用用UML的元素去描述。对整个系统进行用例分析，建立领域模型。针对其中的文件传输的用例做细化，建立设计模型和实施模型，并在设计模型中使用设计模式中的一些方法，例如GRASP等，进行详细的阐述     

Driver usage and understanding of adaptive cruise control

Automation, in terms of systems such as adaptive/active cruise control (ACC) or collision warning systems, is increasingly becoming a part of everyday driving. These systems are not perfect though, and the driver has to be prepared to reclaim control in situations very similar to those the system easily handles by itself. This paper uses a questionnaire answered by 130 ACC users to discuss future research needs in the area of driver assistance systems. Results show that the longer drivers use their systems, the more aware of its limitations they become. Moreover, the drivers report that ACC forces them to take control intermittently. According to theory, this might actually be better than a more perfect system, as it provides preparation for unexpected situations requiring the driver to reclaim control.     

A state-space model for automatic instruction

This paper introduces a state-space instructional model, in which instruction is viewed as a process of transforming the student from one state to another. The model is expressed in terms of state-space problem solving as in artificial intelligence research, an area to which computer-assisted instruction has been increasingly turning for solutions to some of its fundamental problems. The model is first described in general terms and it is explained how the usual concerns of computer-assisted instruction (such as response-sensitivity and individualisation) find expression in the model. The use of the model in the design of teaching programs is illustrated by two systems, for paired-associate teaching and concept teaching. The former involves a re-expression of familiar methods based on the use of mathematical learning models; the latter uses more heuristic methods derived from artificial intelligence. Finally, some comparisons with other instructional models are made.     

Logo: A cause for concern

Over the past few years, the use of Logo in U.K. classrooms has increased very rapidly across all age ranges. It is used extensively as a tool for the development of problem-solving skills, the introduction of information processing techniques and the exploration of geometrical concepts. As a natural consequence of this wide use of Logo, it is becoming the first programming language met by many young learners. Much has been written about the power and appeal of Logo in its educational context, but there has been little consideration of the consequences of such extensive use of Logo as a programming language. It is also being used increasingly in control environments. This has many positive aspects but here too there are problems to be considered.This paper considers the programming environment of Logo and the programming style that it produces. The issues considered raise questions about the way that we teach Logo to children and the extent to which we use it in both pre-service and in-service training of teachers. Whilst recognising the power of Logo, we must also take account of its defects. Some possible strategies are presented.     

基于WESB的Web服务绑定

随着WESB功能的日益强大,越来越多的企业使用WESB在其应用系统之间进行集成。Web服务技术以其标准性和灵活性,逐步成为系统集成中使用的主要技术,WESB的Web服务绑定也就越来越多地被使用,通过解决在实际项目中遇到的问题,提供了一种使用WESB进行集成的新思路,提出了一个将中介模块发布成Web服务的新方法,并解决了因对嵌套WSDL文件支持不足而在集成过程中引发的问题。     

Understanding behaviors of a constructive memory agent: A markov chain analysis

This paper describes a Markov chain analysis of the behaviors of a constructive memory agent. It shows that a constructive memory agent behaves based on the knowledge structures that it has learned from its interaction with the environment. The internal reasoning moves from reactive and reflective to reflexive as the agent acquires more experiences that are increasingly grounded.     

Linux终端的设计与应用

Linux,这个代码开放的系统正在被世界各国政府和各大跨国公司所追捧,其潜在的巨大商机,越来越突出.金融、海关、铁路、证券、航空、图书馆等领域,对这种需求日渐迫切.针对此种情况,提出了一种以Linux操作系统为核心的设计方案--Linux终端,该系统性能高、价格低廉、容易二次开发和维护,且代码开放,能够满足上述领域和其他领域的要求.     

Application of a transparent interface methodology to image processing

Many software engineering projects involve a significant design component in which an algorithm must be formulated as a sequence of processing steps that meets a solution criterion. As the problems tackled become more complex, it becomes increasingly important to create and use tools that help designers understand and manage the design process. We demonstrate the use of design tool called T-STAR in the domain of image processing, in which a toolkit called the TRAnsparent Image Problem Solving Environment (TRAIPSE) is extended to solve face-recognition problems. Key features of TRAIPSE are its visual interface to the space of partial image processing algorithms and its support for automatic assistance in exploring the space. The specific application we present is the analysis of human face images.     

The Realities of CASE

To help manage a large and increasingly complex backlog of systems development projects, more IS departments are turning to computer-aided software engineering (CASE) as their solution. However, this technology has certain barriers to its easy implementation, as shown by the response to a recent Deloitte & Touche survey that addressed (among other things) CASE use in organizations. This article discusses some of the problems of CASE implementation these organizations encountered as well as ways IS departments can overcome these barriers and effectively integrate CASE.     

The Realities of CASE

To help manage a large and increasingly complex backlog of systems development projects, more IS departments are turning to computer-aided software engineering (CASE) as their solution. However, this technology has certain barriers to its easy implementation, as shown by the response to a recent Deloitte & Touche survey that addressed (among other things) CASE use in organizations. This article discusses some of the problems of CASE implementation these organizations encountered as well as ways IS departments can overcome these barriers and effectively integrate CASE.     

Mapping the IEC 62264 models onto the Zachman framework for analysing products information traceability: a case study

In order to face new regulation directives regarding the environment and also for improving their customer relationship, enterprises have to increasingly be more able to manage their product information during the entire lifecycle. One of the objectives among others in this paper is to deal with product traceability along the product lifecycle. To meet this objective, the information system has to be designed and, further built in such a way all information regarding products is recorded. The IEC 62264 standards define generic logical models for exchanging product and process information between business and manufacturing levels of enterprise applications. Thus, it can be a base for product information traceability. However, its complexity comes from the fact it mixes conceptual and implementation details while no methodology exists that defines how to instantiate it. Product traceability is then needed to increase its abstraction level in order to concentrate on its concepts and managing its application by providing a methodology for its instantiation. In this paper, we propose to map the IEC 62264 standard models to a particular view of Zachman framework in order to make the framework concrete as a guideline for applying the standard and for providing the key players in information systems design with a methodology to use the standard for traceability purposes.     

On "Technomethodology": Foundational Relationships Between Ethnomethodology and System Design

Over the past 10 years, the use of sociological methods and sociological reasoning have become more prominent in the analysis and design of interactive systems. For a variety of reasons, one form of sociological inquiry—ethnomethodology—has become something of a favored approach. Our goal in this article is to investigate the consequences of approaching system design from the ethnomethodological perspective. In particular, we are concerned with how ethnomethodology can take a foundational place in the very notion of system design, rather than simply being employed as a resource in aspects of the process, such as requirements elicitation and specification. We begin by outlining the basic elements of ethnomethodology and discussing the place that it has come to occupy in computer-supported cooperative work and, increasingly, in human-computer interaction. We discuss current approaches to the use of ethnomethodology in systems design, and we point to the contrast between the use of ethnomethodology for critique and for design. Currently, understandings of how to use ethnomethodology as a primary aspect of system design are lacking. We outline a new approach and present an extended example of its use. This approach takes as its starting point a relationship between ethnomethodology and system design that is a foundational, theoretical matter rather than simply one of design practice and process. From this foundation, we believe, emerges a new model of interaction with computer systems, which is based on ethnomethodological perspectives on everyday human social action.     

Digital forensics and the issues of identity

The issue of what we consider to be the identity of a person has become increasingly complex as we have made ever greater use of the facilities and services that have been made available by developing technologies and the Internet. In the past people normally had one identity, while in the current environment it is acceptable to maintain separate ‘identities’ for different aspects of our on-line interactions.Proving beyond a reasonable doubt that an individual that is suspected of a crime that is based on the technologies that we increasingly rely on was the actual perpetrator has always been problematic. It is relatively easy to determine the device that was used, but proving that the suspect was the person that used it has always been more difficult.This paper looks at a range of issues that have affected what we consider to be reasonable proof of identity and a number of the problems that this causes in identifying the perpetrator of a crime.     

计算机软件的可靠性设计研究

软件可靠性随着科学技术的逐渐进步已成为我们需要关注的一个问题,软件系统的可靠性随着其规模的加大就会变得越发难以保证。应用本身对系统运行可靠性的要求逐渐增高,尤其是在如航天、航空等一些关键的应用领域,对其可靠性的要求就更加重要,软件系统的可靠性在银行等服务性行业中也和其自身的生存发展竞争能力和声誉有着直接的关系。本文对软件可靠性设计的基本概念进行了介绍,并且对软件可靠性设计方法着重进行了介绍。     

Dubbo服务框架技术在学习系统开发中的应用与实践

随着软件技术和网络的飞速发展,互联网技术越来越多地被应用到了教育领域,互联网教育以其日益丰富的形式和内容被越来越多的人接受和采纳.在线学习已经成为一种新型而且有效的学习方式.在线学习以其独有的时空无关性、及时性、可重复性等特点,使得每一个互联网用户都可以进行在线学习.同时也对在线学习系统提出了一项挑战——如何使学习系统在高并发访问下稳定运行?本文主要介绍以Dubbo分布式架构为后台服务的学习系统的设计与实现.该系统通过教育游戏吸引儿童注意力,提高学习积极性,引导儿童通过网络进行有效的学习;通过Dubbo分布式集群架构,缓解高并发访问时服务器的压力.     

计算机网络防火墙的应用

随着网络应用的日益普及和更为复杂,网络安全事件不断出现,电脑病毒网络化趋势愈来愈明显,垃圾邮件日益猖獗,黑客攻击成指数增长,利用互联网传播有害信息手段日益翻新等等。网络在带给人们自由开放的同时,也带来不可忽视的安全风险。     

网络诱骗与陷阱系统Honeypot

网络攻击和入侵事件的不断发生,给人们造成了巨大的损失,网络安全问题越来越成为社会关注的热点。Honeypot是一种比较新颖的用于网络安全防范的入侵检测技术,通过对Honeypot作用、构建过程和运用的了解,我们可以更好地将其用于网络安全领域。     

Refining visualization reference model for context information

Context-awareness can be used to decrease the need for interaction with a mobile device. This is increasingly important since the functionality of mobile devices and personal digital assistants gets more and more complex while the input and output capabilities remain restricted. An important aspect of context-awareness is to present the current context to the user. We propose a model for visualizing contextual information on the mobile terminal screen. The model is a refinement of a well-known visualization reference model; it takes into account the specific characteristics of mobile use and context information. We present the design of the model in detail, and discuss its applicability for a variety of contexts and tasks by providing a full-fledged use case.     

基于SVG技术的室内地图设计与实现

室内环境导航的需求在今天越来越受关注。目前现有的室内环境地图采用常见的瓦片技术,但它限制室内环境的展示。室内地图与室外地图的特征有着许多区别,尤其是存储室内地图的数量级远小于室外地图。此外移动终端的性能不断提升,能够处理更多更复杂的任务。基于此,室内地图在移动终端独立完成地图解析和展示的任务变得可能,且不影响用户体验。实验证明,采用SVG作为室内地图的数据源,在移动终端解析和展示是可行的,并有更好的用户体验。