嵌入式系统可生存性分析模型研究

嵌入式系统的安全问题日益凸显,为此,提出一种嵌入式系统可生存性分析模型。借鉴近年来国内外研究成果,给出嵌入式系统可生存性的形式化定义,建立系统威胁、系统可生存性需求、系统可生存性策略3个子模型对嵌入式系统可生存性进行分析,形成一套系统可生存性分析的一般流程。实例分析表明,该模型能定量评估嵌入式系统的可生存性,并通过评估结果得到影响系统可生存性的主要因素。     

ExOA2000跨平台

3月18日京华计算机网络系统公司推出可支持多种群件平台、各种操作系统和数据库平台的京华ExOA2000办公自动化系统,公司北京办事处同时成立。该系统包括京华Exflow流转系统、京华Exfile文档系统、京华Exoffice办公系统和京华ExOA用户业务系统等系列产品,这四个系统既可独立运行,又可协同工作。     

FPGA的可重构测控系统应用设计

可重构器件技术的发展和测控系统结构模式的通用化是实现可重构测控系统的前提。通过对常规计算机测控系统存在的问题、结构模式和多任务特征以及可重构器件技术发展的分析,提出基于FPGA器件设计可重构测控系统平台的设想,对可重构测控系统设计原则、硬件结构单元设计和软件重构方法进行了分析,并给出应用于雷达信号实时侦测的基于CPCI总线的可重构测控系统硬件设计的实例。     

多态关联系统可用度的计算模型

可用度是用来评估系统可用性的衡量指标。本文主要对多状态下的关联系统可用度计算模型进行了研究。首先对多状态单系统可用度计算方法进行了分析,然后在此基础上给出了多状态下串联系统、并联系统和k/m系统可用度的计算模型。     

基于着色Petri网的系统可生存性仿真平台

对可生存系统组件在攻击、抵抗、恢复3种因素作用下的状态转换过程进行分析,设计基于着色Petri网的系统可生存性仿真平台,从攻击强度、攻击密度、恢复强度、攻击策略、恢复策略5个方面模拟可生存系统的行为特性。以一个IPTV网络服务系统为例,利用平台仿真其在遭受不同攻击时的服务提供能力。仿真结果表明,该平台能较好地实现系统可生存性分析。     

系统可生存性研究综述

系统可生存性是信息安全的新研究方向，是对传统安全观念的突破和创新。本文首先给出了开展系统可生存性研究的必要性以及系统可生存性若干定义；基于此，结合可生存性的评测和增强技术研究，从计算系统可生存性、网络可生存性、服务可生存性以及软件可生存性4个角度，综述了可生存性的研究现状，并进行了国内外对比分析；随后探讨了可生存系统的设计与实现问题，最后描述了系统可生存性的发展趋势。     

可重构体系结构和特征及应用

文章介绍了可重构体系结构的概念、特征和应用。着重介绍了可重构体系结构的分类及其适用领域,可重构计算系统的总体结构特征和可重构处理单元RPU的结构特征,对基于FPGA的可重构系统和其他可重构系统进行了比较,并总结了当前可重构体系结构的优点以及存在的问题。     

可重构体系结构的特征及应用

文章介绍了可重构体系结构的概念、特征和应用。着重介绍了可重构体系结构的分类及其适用领域,可重构计算系统的总体结构特征和可重构处理单元RPU的结构特征,对基于FPGA的可重构系统和其他可重构系统进行了比较,并总结了当前可重构体系结构的优点以及存在的问题。     

Windows7各种安装方法大总结

光盘安装法：光盘安装法可以算是最经典、兼容性最好、最简单易学的安装方法了。可升级安装。也可全新安装（安装时可选择格式化旧系统分区）,安装方式灵活。不受旧系统限制,可灵活安装32／64位系统。方法：1、下载相关系统安装盘的ISO文件,刻盘备用。（有光盘可省略此步骤）     

基于随机Petri网的电信交换系统可生存性分析

网络系统的可生存性问题是系统安全领域的一个重点研究方向。讨论现有的系统可生存性的一般分析方法,确定系统的可生存属性,并采用随机Petri网(SPN)技术,分析电信交换系统生存性问题的特点。重点利用随机Petri网描述系统的失效-修复分析模型和性能分析模型,给出系统可生存性分析中主要指标的定量计算方法。系统仿真结果表明了该方法的有效、合理性。     

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。     

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.