基于Minix的进程间通信系统的设计与实现①

进程间通信作为操作系统中最重要的原语之一,提供了在多个隔离的进程之间相互通信交流的可能性.提出了一种适用于微内核操作系统的进程间通信系统,并在具体的Minix操作系统平台之上予以实现,解决了Minix系统中由于进程间通信模块的缺失而导致开发人员无法顺利移植其他平台的实用程序的问题。实验数据表明,该进程间通信系统具有高效的特点;同时由于该系统的设计原则,它保持着易扩展的特点。该系统的实现虽然是基于Minix平台,但该设计同样适用于其他微内核的系统,对其他操作系统具有借鉴意义。     

基于Minix的进程间通信系统的设计与实现①

进程间通信作为操作系统中最重要的原语之一,提供了在多个隔离的进程之间相互通信交流的可能性．提出了一种适用于微内核操作系统的进程间通信系统,并在具体的Minix操作系统平台之上予以实现,解决了Minix系统中由于进程间通信模块的缺失而导致开发人员无法顺利移植其他平台的实用程序的问题。实验数据表明,该进程间通信系统具有高效的特点;同时由于该系统的设计原则。它保持着易扩展的特点。该系统的实现虽然是基于Minix平台,但该设计同样适用于其他微内核的系统,对其他操作系统具有借鉴意义。     

微内核架构多线程机制的形式化设计研究

微内核架构因其有效的模块隔离性而成为操作系统方面研究的热点,多线程机制是微内核架构需要解决的关键性能问题。有不少的工作对微内核架构多线程机制进行了研究,但存在频繁的系统地址空间切换和实现复杂度高的问题。采用形式化的方式对微内核架构多线程和安全机制进行描述和设计,提出一个微内核线程分层对象语义模型,用以 设计多线程机制的线程间通信、调度和互斥同步方案。在已实现和验证的微内核操作系统VTOS中对多线程功能和性能进行了测试,结果表明 VTOS有效地实现了多线程机制,并具有很好的系统性能。     

支持多核架构的微内核操作系统设计

针对多核架构开始在嵌入式领域普及的趋势,设计一个基于多核处理器架构的微内核操作系统,描述系统中内存管理、线程调度、锁和中断、线程间通信以及应用程序等各部分的设计方案。该设计充分利用多核架构和微内核操作系统的特点,不仅应用于与Intel公司合作的L4微内核操作系统研究项目,也为其他微内核操作系统设计提供了参考。     

基于TEMU的进程间通信过程逆向

传统的逆向分析方法在分析多进程架构软件时具有较多难以克服的困难, 针对这个问题提出了基于TEMU的进程间通信过程逆向方法。利用动态二进制分析平台TEMU记录多进程程序函数调用信息, 结合进程间通信函数的关联规则从函数调用信息中提取进程间通信的通信方法、通信数据和通信协作机制。根据该方法设计并实现了一个原型系统, 对多款多进程架构软件进行测试, 测试结果表明, 该方法能够准确提取多进程架构软件的进程间通信过程, 对多进程架构软件逆向起到了很大的辅助作用。     

通过单地址空间提高微内核操作系统的效率

提出了一个提高微内核操作系统效率的方法,该方法通过在操作系统中实现单地址空间,操作系统内核程序和用户程序在一个处理抗状态下运行 ,以及复ｄａｐａｂｉｌｉｔｙ实施对资源的保护,使得当进程通过进程通信访问服务器提供的服务时,其代价将接近执行调用的代价,从而提高了微内核结构操作系统的改进。     

分区间通信在机载计算机系统中的应用研究

在机载计算机系统中不同系统之间的通信是系统集成中需要重点考虑的问题之一.介绍了近年机载计算机系统的发展过程.随着顶层体系架构的发展,随之产生了分区操作系统.在分区操作系统中分区间的通信和传统的通信方式有很多不同.就分区间通信的优点和缺点进行了详细的阐述,最后得出了对分区间通信进行限制的必要性及具体的限制措施.     

基于微内核的虚拟机间通信加速方法

基于微内核的虚拟化架构相较于传统的宏内核虚拟化架构,具有可信计算基小,易于完全形式化验证的特点.然而,在基于微内核的虚拟化架构中,即使在同一物理机上运行的不同虚拟机,虚拟机间通信仍需要通过调用网卡驱动传输数据,通信效率低.针对以上问题,提出了一种同一物理机上不同虚拟机间的通信加速方法,通过在网络服务中加入通信数据选择模块和转发模块,使得虚拟机间数据的传输可以直接在内存中完成.实验表明,可以有效提高虚拟机间的通信效率.     

一个教学用操作系统的设计与实现

本文首先指出了现有的教学用操作系统存在的不足,然后设计并实现了一个运行在虚拟机上的微内核结构的教学用操作系统,描述了系统中进程管理、进程间通信、基本内存管理、磁盘服务器以及文件服务器的设计和实现。本系统的实现将有利于学生从微观上观察操作系统的行为特征,并且帮助他们理论联系实际,具有较好的教学价值。     

一种安全高效的Java操作系统IPC机制的设计与实现

安全高效的进程间通信机制是操作系统中实现进程间协同工作的关键.针对现有Java操作系统普遍使用的共享堆和Java远程过程调用(RMI)等进程间通信机制在安全性、高效性等方面的缺陷,面向Java操作系统的结构特点和进程间通信需求,设计和实现了一种新的安全、高效的进程间通信机制MSP.MSP机制通过区分小尺寸和大尺寸消息,...     

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     

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.     

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。