在TCP/IP网络支持下的Client/Server编程技术

一、引言 1.网络应用程序接口socket介绍 通常用户可利用网络操作系统提供的命令,如ftp,rcp,rcmd,rlogin等来进行网络操作。但用户应用程序则需要利用TCP/IP提供的网络应用程序接口(API)来实现进程间通信。TCP/IP提供的网络API主要是socket。socket的目的是解决网间网进程通信问题,一般UNIX系统进程通信是在同一台主机内不同的进程间的通信,主要是利用进程通信机制(IPC)来实现的,通信双方可用各自的进程号来标识。但是在网络上进程间通信就比较复杂了,此时大部分通信是发     

UNIX操作系统的模块化设计

本文从结构程序设计的观点分析了UNIX 操作系统结构上的一些问题,介绍了重新设计的UNIX操作系统核心结构及在设计中采用的方法。最后,讨论了在用XCY语言改写这一系统时要处理的该语言与操作系统的接口问题。     

基于Delphi与OpenGL的三维图形环境的构建

OpenGL实际上是一种图形与硬件的接口,是一个强大的3D图形库。Delphi是Windows平台下最好的开发工具之一。介绍了OpenGL绘图与Windows编程的联系：阐述了实现Delphi和OpenGL图形接口主要的工作是初始化OpenGL、设置像素格式、关联RC（RenderingContexts）和DC（DeviceContexts）,从而实现与OpenGL在Windows操作系统下的图形接口,以构建三维图形开发环境。     

基于Netlink机制的1553B协议通用接口设计

Netlink是Linux系统下的一种全新的协议族,其实现了进程间通信功能.文中在参考了linux操作系统下Netlink机制和1553B协议的实现,研究了将1553B协议和基于Netlink机制的socket套接字相结合之后,设计了一套基于Netlink机制的1553B协议通用接口.该套接口的实现是通过Netlink通信机制对socket下的协议栈进行了扩展和定义.文中实现了基于Netlink机制下使用socket API传输1553B数据的功能.通过实验验证了通用接口的便利性.     

用VisualC＋＋6.0实现Sockets编程

Sockets最早是作为UNIX BSD(Berkeley Software Distribution)Release 4.3规范提出来的,随着网络的迅速发展以及Internet在全球范围内的广泛使用,Sockets已逐渐成为网络编程的通用接口。作为网络通信的基本操作单元,它提供了不同主机间进程双向通信的端点,使编程人员能够简单地对网络进行操作,构造任意的跨操作系统、跨网络协议的分布式处理系统。 一、Windows Sockets功能简介 Microsoft公司开发的Windows Sockets API建立了Windows环境与网络间的编程接口,它以BSD Sockets的编程模块为基础,提供了16位和32位两种版本。根据传输的数据类型不同,Windows So-     

用Java Socket实现网络聊天室

Socket是进行网络通信编程的API,也是unix、linux、windows等操作系统的通用网络编程标准。在网络编程中最常用的方案便是客户/服务器模型。本文提出了在客户机/服务器模型下用java socket实现Internet中常见的聊天室软件的解决方案。 一、Socket简介 Socket实际在计算机中提供了一个通信端口,可以通过这个端口与任何一个具有Socket接口的计算机通信。应用     

开发支持IPv6的应用程序

随着IPv6(Internet Protocol Version 6）网络的部署,程序员必须面对多种地址协议族（Address Families,AF)的接口（socket）连接问题,使其程序同时支持IPv6和IPv4。结合作者的实验经验,研究网络编程时处理多个地址协议族的问题,以期实现与地址协议族无关的编程。     

UNIX系统讲座 第一讲 使用UNIX系统的初步知识——入门

序言 UNIX系统是国际上最为著名的操作系统之一,特别是七十年代末到八十年代初,UNIX系统越来越引起人们的重视,尤其在小型和微型计算机上,也广泛的配有UNIX操作系统,例如DUAL68000及IBM-PC-AT(类似UNIX的操作系统)等机器。在巨型机及大型机上也广泛采用,如IBM370及Amdahl 470巨型机。因此UNIX操作系统现在已成为唯一能够在微型机、小型机、中型机、大型机及巨型机上广泛使用的一种操作系统。近来我国引进或组装的小型及微型机中,也大量的带有UNIX系统或者类似UNIX的     

在UNIX下对文件与目录进行编程

近来,随着UNIX系统的不断普及,使用UNIX系统的单位和个人也越来越多,特别是Linux的推出,更是风靡全球。基于UNIX系统的编程也愈显重要。本文以一个简单的程序为例,说明怎样在UNIX系统下对文件和目录进行编程。该例是一个类似于UNIX系统命令ls的程序,用于列出指定的目录中所有文件和子目录并计算出指定目录所用的磁盘空间。 一、UNIX文件系统简介 文件是通过操作系统来管理的。文件的结构以及命名、存取、使用、保护和实现方法都是UNIX系统中的重要内容。总体上,UNIX系统中处理文件的那部分称为文件系统。同DOS类似,UNIX中的文件系统被组织成树状结构。 UNIX中的文件和目录通过一个9比特的保护码来进行保     

Linux环境下的MATLAB混编方法研究及应用

随着基于Linux操作系统下的开发愈加广泛,研究Linux环境下的MATLAB仿真平台及MATLAB的混合编程方法将是十分必要的。根据搭建小型无人直升机仿真平台的需要,本文提出了一种在Linux操作系统环境下,应用MAT-LAB与C语言的接口C-MEX函数,实现读取系统硬件设备（joystick）数据的方法,实例验证方法的可行性。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.