英特尔官司上身

英特尔将继微软之后,成为美国司法部的下一个诉讼对象,司法部将起诉英特尔试图抑制市场竞争。 这场反托拉斯法诉讼将在美国联邦贸易委员会(FTC)与英特尔公司之间进行。该诉讼案预计将历时三个月,约有50人将出庭作证。 据悉,FTC将指控英特     

IDC对网络安全市场做全新的展望

安全硬件及芯片将渗透到安全的每一个领域 体现在：几乎所有的网络安全软件厂商将很快提供网络安全硬件设备：到2007年将有大约80％的安全产品将是网络安全硬件设备；网络安全软件将在硬件平台的选择上更加灵活；“CD Appliance”将能使软件解决方案快速地集成到硬件设备上；更多的安全软件特征将加在已有的设备上．     

软件推波存储潮

据预测,2001年存储市场的增长将超过服务器市场,存储需求将占到整个 IT 需求的50%;而到2003年,这种需求将达到75%;存储应用也将转向数据管理,用户建造IT 系统的指导思想将从以服务器为中心向以数据管理为中心的模式转变。这一切都表明,2001年将是一个存储年。     

TD-SCDMA论坛与CDMA发展组织签署合作协议

据报道，TD-SCDMA论坛和CDMA发展组织（CDG）签署了合作协议，双方在技术、管理、标准、营销与公众关系和信息交换等方面将加强合作．双方还将联合将促进TD-SCDMA的发展并且还将为TD-SCDMA寻找全世界其它地区发展的机会．在战略、标准和技术互动等领域双方将达成伙伴关系．为促进行高级3G服务应用，还将在应用与功能开发上进行合作．TD-SCDMA论坛和CDG将共同努力促进TD-SCDMA和CDMA2000系统之间漫游性能，另外在无线技术的未来演变过程中还将合作下去．在治理无线通信管理问题上，TD-SCDMA论坛和CDG将针对高级无线服务促进频谱分派，并且还将促进有利高级无线服务发展的管理政策制定．双方将保持信息交换，在进行有利于两方的营销和公共关系项目与活动时要通知对方．     

2008年IT行业十大预测（一）

桌面虚拟化技术将不会成为主流;收购和并购交易将会减少;采用Vista SlideShow技术的笔记本将真正到来;音乐公司将放弃原有的数字版权保护（DRM）政策     

Eckard Pfeiffer——寻找PC驱动力

5年内,业界将形成4家厂商占据全球70％市场的格局,Compaq将是其中之一,这是Compaq总裁Eckhard Pfeiffer的预言。在他以客户为中心的讲话中指出:未来将取决于一件事,那就是为客户提供令人满意的方案及充足的经验,客户必须从技术及服务中获益,客户服务将决定客户的购买行为,必须使客户从我们的技术、产品和服务中充分受益。那些通过E-Mail作生意的厂商的优势将丧失怠尽。PC将趋向复杂化,小企业的PC应用将会大量增加,PC技术将渗透到生活的各个层面。“计算机工业的未来将来自于向客户提供最令人满意的产品和经验。我谈到的未来比我们现在任何可以看到的东西部更具挑战性。PC应用的领域将得到拓展,将远远超过我们今天的想象。”为了     

股市风向标

个人电脑销售增速将放缓 一些业界高层人士认为,个人电脑销售今年对本行业产生的影响将日趋减小。据预测,美国个人电脑消费量今年完一季度将与去年同期持平或出现下降。缺之新技术和这一市场几家大公司的退出是其中的主要原因。另外,消费者将越来越看重上网速度而非电脑运行速度的加快。如果这种预测成为现实,几周以前开始的局面将会再次重复,个人电脑销售的增长将会放缓,而平均销售价格也将被拉平。     

企业级基础设施十大趋势

未来五年,非结构化数据将大幅度增加,总数据量将增长800％,非结构化数据将占80％,如此大量的数据内容将会给企业级基础架构带来怎样的挑战呢？     

风向

Gartner:今年全球芯片销售将增22.6%据Gartner预测,2004年全球芯片销售收入将比去年增长22.6%,超过2170亿美元。芯片市场的兴衰周期在2005年将达到顶点,达到2450亿美元。2004年供货紧张的环境将给芯片厂商带来更多的收入和利润,同时,半导体厂商的金融状况将得到改善并且将增加资本开支。Gartner还表示,尽管供货量紧张将使价格在短期内上涨,但需求可能会继续增长。不过,随着企业在2005年投资升级其计算机设备,半导体供货量将增长而且价格会开始下降。2006年芯片行业的销售收入将比2005年下降大约2.6%,销售收入大约是2402亿美元。IDC:2007…     

2009年互联网十大趋势

面对全球经济危机挑战,务实创新,将成为2009年互联网的主旋律。一、互联网将进一步走向开放：全球经济危机将使互联网产生分化,与美国某些专家的看法相反,互联网总趋势将进一步走向开放。2009年的中国互联网将以开放为主流趋势：以阿里巴巴、腾讯、盛大等“平台开放,增值赢利”为代表的开放模式将日益主流化;UCWEB等移动开放平台呈现广阔发展空间;开放性概念如“智慧地球”、“云计算”将引领潮流。     

基于数字化平台的柴油机电控系统可靠性计算

为了评估核电厂应急柴油机数字化控制方案替代部分传统继电器控制系统的可行性,对基于数字化专用仪控平台的柴油机电控系统进行了可靠性分析和计算。依据该系统的架构设计,建立了系统可靠性框图模型,并结合可靠性设计和失效率预计数据,采用蒙特卡罗方法计算得到的系统可用性达到99.99%。分析结果表明,冗余设计、故障诊断和维修性设计对系统可用性影响显著。该研究结论为柴油机电控系统的数字化改造提供了可靠性数据参考,并有助于同类系统在设计阶段有效地提升固有可靠性。多种可靠性分析方法从系统架构、功能安全和运行维护方面更准确地描述了电控系统的可用性,为数字化仪控设备的可靠性分析提供了方法借鉴。     

基于CORBA的分布对象容错机制研究与实现

一、引言目前,以CORBA为代表的分布对象计算技术已日趋成熟,越来越多的分布式应用系统利用CORBA提供的标准服务和协议来实现。基于CORBA的新一代的分布式系统,如分布式实时控制系统、在线支付系统和股票交易系统,需要可靠性保证。容错技术是分布式系统运行过程中可靠性保证的重要手段,可以在分布式系统的每一个层次实现,利用底层的CORBA基础设施提供容错机制具有显著的优势,既能够避免系统层为支持容错而做的巨大改变,又能够简化应用软件的设计。因此,容错CORBA已经成为国外CORBA研究的重     

A model for availability analysis of distributed software/hardware systems

System availability is a major performance concern in distributed systems design and analysis. A typical kind of application on distributed systems has a homogeneously distributed software/hardware structure. That is, identical copies of distributed application software run on the same type of computers. In this paper, the system availability for this type of system is studied. Such a study is useful when studying optimal testing time or testing resource allocation. We consider both the case of simple two-host system, and also the more general case of multi-host system. A Markov model is developed and equations are derived to obtain the steady-state availability. Both software and hardware failures are considered, assuming that software faults are constantly being identified and removed upon a failure. Although a specific model for software reliability is used for illustration, the approach is a general one. Comparisons show that system availability changes in a similar way to single-host based software/hardware systems. Sensitivity analysis is also presented. In addition, the assumptions used in this paper are discussed.     

Optimal number of hosts in a distributed system based on cost criteria

Redundant or distributed systems are increasingly used in system design so that the required reliability and availability can be easily achieved. However, such an approach requires additional resources that can be very costly. Hence, how to design and test such a system in the most cost-effective way is of concern to the developers. A general cost model and a solution algorithm are presented for the determination of the optimal number of hosts and optimal system debugging time that minimize the total cost while achieving a certain performance objective. During testing, software faults are corrected and the reliability shows an increasing trend, and hence system reliability increases. A general system model is constructed based on a Markov process with software reliability and availability obtained from software reliability growth models. The optimization problem is formulated based on the cost criteria and the solution procedure is described. An application example is presented.     

一种新型的能够防止两块磁盘失败的技术

海量存储系统的建设是目前计算机系统最热门和发展最快的领域,存储系统的主要部分是在线存储系统。RAID(磁盘阵列)对于提升存储系统的效率、数据的高可靠性、防止数据破坏和业务停顿具有重大意义。目前实际应用中的RAID 1,RAID 0+1,RAID 4,RAID 5都只能防止单块磁盘的损坏,实际生产中已经出现了很多由于双盘损坏造成业务长时间停顿的事故。在介绍了通用的RAID级别的基础上,介绍了一种新型的对角线奇偶校验方法,结合水平奇偶校验,可以防止两块磁盘损坏。通过可靠的数学分析,可以看到该方法可以极大提高磁     

Reliability modelling of redundant computer systems with common-cause failures

This paper presents a common-cause failure analysis of redundant computer systems. Three mathematical models representing a two-unit redundant computer system are developed. Computer system reliability, steady-state availability, mean time to failure and variance of time to failure formulas are developed. In addition, a general formula for redundant computer system steady-state availability is derived when the failed computer system repair times are described by Erlangian distribution. The computer system reliability, availability and mean time to failure plots are shown.     

混合控制系统及其分析与设计方法

混合控制系统是指那些由实时产了系统和实时数值反馈子系统组成的系统，这类系统的特点是事件变量和时间变量的演化在不同系统内并行，实时地进行，本文基于对混合控制系统以往研究框架的分析，给出了混合控制系统的一个新框架，并提出了混合动态系统的分析和设计方法，混合控制系统的包括系统性能指标的分解，决策子系统的设计和实时数值反馈子系统的设计，其分析则分为离散时间域和离散事件域分析，文中采用了煤气炉系统作为例子说     

Performance and reliability improvement by using asynchronous algorithms in disk buffer cache memory

This paper proposes performance and reliability improvement by using new algorithms for asynchronous operations in disk buffer cache memory. These algorithms allow for writing the files into the buffer cache by the processes and consider the number of active processes in the system and the length of the queue to the disk buffer cache. Writing the contents of the buffer cache to the disk depends on the system load and the write activity. Performance and reliability measures including the elapsed time of writing a file into the buffer cache, the waiting time to start writing a file, and the mean number of blocks written to the disk between system failures are used to show performance and reliability improvement by using the algorithms. Sensitivity analysis is used to influence the algorithms' design. Examples of real systems are used to show the numerical results of performance and reliability improvement in different systems with various disk cache parameters and file sizes.     

基于传感器模型的安全计算机仿真系统

在安全计算机信号系统的研发与测试中,没有真实的传感器接入会带来测试难、验证难等问题。为此,设计一种基于传感器模型的轨道交通安全计算机平台仿真系统。以真实的传感器为模型基础进行传感器建模,控制真实的硬件输出,通过软硬件结合的方法为安全计算机平台提供真实的输入与输出。同时利用软件修改模型参数,模拟传感器故障,为安全计算机平台提供无损坏的故障注入。测试结果证明,该仿真系统能够有效验证安全计算机平台的安全性、可靠性与可用性,加快安全计算机平台的开发进程。     

Modeling and Tracking of Transaction Flow Dynamics for Fault Detection in Complex Systems

With the prevalence of Internet services and the increase of their complexity, there is a growing need to improve their operational reliability and availability. While a large amount of monitoring data can be collected from systems for fault analysis, it is hard to correlate this data effectively across distributed systems and observation time. In this paper, we analyze the mass characteristics of user requests and propose a novel approach to model and track transaction flow dynamics for fault detection in complex information systems. We measure the flow intensity at multiple checkpoints inside the system and apply system identification methods to model transaction flow dynamics between these measurements. With the learned analytical models, a model-based fault detection and isolation method is applied to track the flow dynamics in real time for fault detection. We also propose an algorithm to automatically search and validate the dynamic relationship between randomly selected monitoring points. Our algorithm enables systems to have self-cognition capability for system management. Our approach is tested in a real system with a list of injected faults. Experimental results demonstrate the effectiveness of our approach and algorithms