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.     

Linux安全模块的设计与实现

Linux安全模块是为Linux内核开发的一款轻量级的通用访问控制框架,这种访问控制框架能使许多的访问控制模型作为动态内核模块执行.文中阐述了Linux安全模块的设计思路以及实现方法,并且讨论了如何在对Linux内核影响最小的情况下探索一个有效的解决方案.     

Linux内核动态模块开发分析

Linux内核动态模块（LKM）是Linux用于扩充其功能的重要手段，它允许一些模块动态地加载和卸载，而不需要重新编译内核。结合最新的Linux内核发展情况，不仅分析了模块加载的原理，而且分析了具体的方法和注意事项，同时给出了相应的例子，还提供了相关的Linux常用命令，对相关的开发有指导意义。     

Linux 2.6内核IPSec支持机构的研究与分析

新的Linux2.6内核提供了对IPSec的支持机构,文中对Linux 2.6内核中新加入的IPSec代码进行了深入分析。对比先前不支持IPSec的网络协议栈的Linux内核,揭示了Linux 2.6内核“无缝”接入IPSec处理的方法;阐述了内核中IPSec重要组件——安全关联SA、安全策略的设计思想以及相关数据库SAD和SPD的构建方法;分析了基于Netlink套接字通信的内核IPSec管理模块、内核加密算法函数库,总结出一套Linux 2.6内核IPSec支持机构提供给用户进程的调用方法。     

Linux内核跟踪机制LTT的研究

LTT(Linux Trace Toolkit)是Linux内核性能分析工具,由探测内核、数据收集模块、数据提交守护进程、数据表示和分析软件4部分组成,它主要对内核事件进行跟踪,提供精确详细的跟踪信息重构特定时间段内系统行为,使得用户正确了解系统动态,并为后期数据处理提供特色图形化显示和分析工具。经过测试,运行LTT开销低廉,能够有效帮助用户识别性能瓶颈。     

Linux内核2．6进程调度分析与改进

对Linux内核2.6进行了进程调度分析,阐述了Linux内核2.6提高实时性的各方面因素.同时针对Linux内核2.6三种基本的调度策略SCHED-OTHER,SCHED-FIFO,SCHED-RR存在调度实时性不强的问题,提出了四种改进调度实时性的调度算法:静态优先级的RM调度算法,动态优先级的EDF,LSF调度算法及一种混合的调度算法.这四种方法都在不同程度上提高了Linux内核2.6的实时性能.为了让Linux更好地应用到实时系统中去,今后应当研究更切实有效的调度算法来提高Linux实时性.     

Linux 2.6内核IPSec支持机构的研究与分析

新的Linux2．6内核提供了对IPSec的支持机构，文中对Linux2．6内核中新加入的IPSec代码进行了深入分析。对比先前不支持IPSec的网络协议栈的Linux内核，揭示了Linux 2．6内核“无缝”接入IPSec处理的方法；阐述了内核中IPSec重要组件——安全关联SA、安全策略的设计思想以及相关数据库SAD和SPD的构建方法；分析了基于Netlink套接字通信的内核IPSec管理模块、内核加密算法函数库，总结出一套Linux 2．6内核IPSec支持机构提供给用户进程的调用方法。     

Linux内核数据采集的一种有效方法

为了分析改进Linux内核，有必要从运行的内核提取信息。基于内核调试器Kprobe，提出了一个动态采集大量内核数据的有效方法。方法尽可能地减小探测器在内核控制路径上的开销，适用于各种不同的环境。     

ARM Linux内核编译及在Skyeye上模拟移植

以Linux操作系统环境为例,介绍如何在Linux操作系统下建立嵌入式交叉编译环境,并使用交叉编译工具编译嵌入式Linux内核,以及在Skyeye上模拟Linux操作系统内核移植。在ARM Linux内核交叉编译部分以S3C2410X目标机处理器,生成可在其上运行的Linux内核,内核版本为最新的Linux-2.6.39。     

嵌入式Linux的动态扩展技术研究

随着嵌入式技术的快速发展和嵌入式设备的普及,嵌入式应用发展的一个关键趋势是从静态的、固定的系统功能到动态的、可扩展的系统功能。本文主要进行嵌入式Linux系统内核动态扩展技术的讨论。首先,介绍嵌入式Linux系统的发展状况和研究嵌入式 Linux动态扩展性的意义。然后,讨论目前几种主要的核心动态扩展技术,以及各种技术在嵌入式系统上的优缺点。最后,分析嵌入式 Linux动态扩展性研究所面临的挑战和发展趋势。     

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。     

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.     

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.     

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.