Linux内核启动过程分析

结合Linux内核代码,分析了80x86平台上Linux操作系统内核的启动过程,特别对内核的动态加载、CPU工作模式的转换以及内存分页机制最终启动的全过程做了较为细致的阐述.该分析有助于更深入地了解Linux内核的工作原理和多任务操作系统的实现机理,是将Linux运用于嵌入式系统的前期工作.     

基于ARM平台的Linux内核分析与移植研究

搭建以S3C2440A(ARM920T核)微处理器为核心的硬件平台,分析Linux内核启动的过程,阐述移植要点,介绍Linux的源代码结构。针对Netfilter嵌入式防火墙的应用需求做具体的研究和开发,并对内核进行相应的修改和优化。通过配置、编译完成整个移植过程,为Linux内核移植提供借鉴。     

Linux内核中信号量机制的研究与实现

信号量是Linux内核中对竞相进入临界区的进程进行同步机制的有效手段。即使在最新版本的Linux-2.6.12内核中,也没有对等待进入临界区的进程链表进行优化,在实时系统中这是一个缺陷,本文重点通过研究内核下的信号量同步机制,针对实时系统提出一种改进的方案。     

基于内核启动优化的嵌入式Linux快速启动方案

快速启动是嵌入式Linux需要解决的关键问题.在比较目前加速嵌入式Linux启动的几种方法的基础上,给出了一种针对内核启动优化的快速启动方案.通过测量内核启动过程时间,荻取了主要的延时因素,以此为依据,引入Kernel XIP技术消除了内核映像拷贝解压时间,提出了不检测、并行检测、驱动模块化、驱动管理优化等加速设备初始化策略,设计了一种既适合快速启动又实用的文件系统架构.试验结果表明,该方案明显地加快了嵌入式Linux的启动速度.     

一种基于Linux Live USB的启动优化研究

Live USB上的Linux内核启动时间较长,这使Linux在Live USB上的普及受到了一定的限制。现存的对其进行优化的方法主要是通过配置Linux内核模块以及Linux内核运行参数以减少其启动时间,但这些优化方法并没有对占据大量Linux内核启动时间的设备初始化过程进行优化。为此,提出了一种针对PCI设备的初始化过程进行优化的方法,该方法的思想是通过已知信息,移除探测PCI总线上的设备的时间。实验结果表明该方法能够进一步减少Linux的启动时间,启动速度提升幅度达到21.25%。     

Linux启动过程分析

随着IT行业的发展,嵌入式系统日益重要,尤其是Linux操作系统更是得到了极高的重视与广泛的应用。本文以VMware虚拟机为工具,以fedora8及2．6．23内核版本为例,详细分析Linux操作系统的启动过程;并把启动过程分为硬件初始化、内核引导、运行init程序、建立终端等4部分。分析每个阶段的执行过程并画出整个操作系统的启动过程流程图。对Linux操作系统启动过程的分析,是进一步分析Linux内核及裁剪linux操作系统和最终将Linux用于嵌入式系统的基础工作。     

Linux系统引导概述

Linux操作系统在当今有着广泛的应用,系统引导是操作系统启动不可或缺的重要步骤.文中描述了在X86体系结构的系统中,从系统加电的一刻起,Linux内核是如何逐步加载到内存中并开始初始化的,通过对Linux启动部分源代码和相关文档的分析,介绍了BIOS读取引导扇区代码和实模式下初始化例程加载内核映像的过程.这对于嵌入式操作系统引导程序开发具有一定参考作用.     

基于状态恢复的嵌入式Linux快速引导

提高系统在配置较低的嵌入式设备上的启动速度,对嵌入式Linux的推广应用具有重要的意义.详细分析了嵌入式Linux启动引导过程中的Bootloader部分和内核的初始化部分之后,通过对部分内核源代码的修改及U-boot的重新设计实现,提出了一种基于状态恢复的系统快速引导策略,并在基于Intel Xseale的嵌入式开发板上进行了验证.     

U-Boot在LPC2210上的移植分析

在嵌入式系统中运行Linux变得越来越广泛,而启动引导程序Bootloader的开发是嵌入式操作系统移植的一个重要环节,在内核映像执行前完成相关的底层硬件的初始化工作,建立内存空间的映射图等重要工作,然后为内核提供引导参数,启动内核.U-Boot软件是一种功能强大的开源Bootloader,本文详细的分析了U-Boot软件针对LPC2210处理器的移植方法、移植过程及相关要点.     

Linux在嵌入式系统中的实现

本文在对Linux的内核结构、启动过程进行分析的基础上,分析并给出了Linux内核向嵌入式系统中移植的方法,其中包括开发平台的建立、内核裁减的方法、内核在CF存储卡上的安装及引导过程。     

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.