异构备份网络的病毒传播模型及稳定性分析

针对云计算、数据中心等基于虚拟网络的环境中病毒二次攻击的问题，研究了平台动态防御背景下的病毒传播及免疫机理，并提出一种异构备份式的网络病毒防御方法。首先，分析冗余备份发生二次攻击的过程，并总结病毒作用规律；同时，结合平台动态防御的思想，引入异构平台状态节点，并提出了易感-潜伏-感染-免疫-异构-易感（SEIRHS）病毒传播模型；其次，运用劳斯-赫尔维茨稳定性判据证明了模型平衡点处的局部稳定性，并求解基本再生数；最后，通过实验仿真分析对比了所提模型与传统易感-感染-免疫（SIR）模型、易感-潜伏-感染-免疫（SEIR）模型，并验证了所提模型的稳定性，探讨了病毒传播影响因子对病毒扩散规模的作用结果。仿真结果表明，所提模型能客观反映病毒在网络中的传播规律，并通过降低节点度、提高感染-异构（I-H）状态转移概率、降低备份时已被病毒潜伏的概率等有效提升网络对病毒的防御效果。     

异构网络文件打印共享及Samba安全管理研究

通过对异构网络文件打印共享方式NFS、CIFS和Samba服务器的分析比较,提出了完整的Samba服务器管理体系及安全策略,使Samba服务器在异构网络环境中的应用更加稳定、安全.主要包括5个层次:Linux系统管理、Samba安全配置、访问控制、日志管理、系统备份与恢复,对于每个层次的安全管理策略进行了相应的分析讨论.实践证明,这种安全管理体系与策略具有很好的实用性,有助于异构网络环境下的应用性研究与开发.     

区域网络中异构数据库存储复制技术

传统异构数据库存储复制技术只注重数据安全性,忽略了异构数据库存储复制的时效性与可靠性。为此,本文提出一种新的区域网络异构数据库存储复制技术。首先构建区域网络中异构数据库存储框架,通过定向随机游走方法对电力企业灾备中心异构数据进行存储,依据多叉索引树对异构数据库中的数据进行查询处理。然后采用一致性树分布备份技术对本地灾备中心数据进行备份,把待恢复数据分割成若干部分,通过若干差异远程备份服务器实现数据恢复。将所提技术应用于电力企业灾备中心,结果表明,所提技术有很高的存储、复制及备份恢复性能。     

异构数据库之间的数据集成和备份模型

针对目前的海量数据的备份，以实现图方式实现数据仓库的数据集成。提出异构数据库之间的数据集成和备份的PBIHD三层模型，模型中中间控制层通过算法对数据库集成和备份进行了优化，并实现异构数据之间的数据转换，最后给出了模型的实现。     

基于HASH算法的优化网络备份系统研究

本文首先对网络备份系统的概念以及其系统的结构进行了阐述，接着选择了HASH算法，从实际出发，应用HASH算法改进备份策略，均衡和提高备份和恢复的效率，简化过程，提高数据安全性，减少数据一致性问题，提升了系统整体性能。最后，在100M局域网的环境中，分大文件和小文件两种情况，对网络设备系统进行了性能测试和分析，发现相时于标准程序ftp，网络备份系统的数据传输率提高了很多。     

网络数据备份系统的规划

本文对网络环境下数据备份的软、硬件系统及备份策略进行了分析和介绍，提出了一些备份系统实施过程应注意的问题。     

英汉对照软件专业时文选读

分布式备份 据最近估测,存储在网络上的数据每年以40％以上的速率增长着。这样的增长速度带来了包括如何备份这些数据等各种各样令人关心的问题。 备份技术在主机环境中已相当成熟,然而在客户机/服务器网络中仍在继续发展。一种新的称作为分布式备份的策略采用了分布式存储设备,而又同时保留了集中式控制。这种策略能改进现驻留在网络环境中关键数据的安全,并能减少因越来越多的数据在网络上运行而产生的问题。     

异构环境下改进的LATE调度算法

针对异构环境下LATE算法在选择备份任务及执行节点时的不足,提出一个改进的IR-LATE调度算法。算法通过计算为剩余完成时间最长、最需要备份的慢任务启动备份,并将其按负载不同进行分类,结合轮询算法,将备份任务分配到负载最小且成功/负载比高的节点上执行。实验结果表明,该算法与LATE算法比较,有效的将作业完成时间缩短了30%左右,提高了执行效率,进而促进系统的负载均衡。     

利用任务计划实现自动备份

很多朋友都已经开始使用Windows7，这个系统引入了一个完整计算机的备份机制，可以将整个计算机进行完整备份，包括Windows操作系统本身，甚至还可以保存在网络驱动器。在Windows Vism时代，并不能在图形界面下实现定期自动创建系统映像的任务，Windows7不仅突破了这一限制，而且还可以使用wbadmin命令在命令提示符环境下创建系统盘的完整备份。     

基于移动Agent的备份管理系统的设计和实现

备份是一种重要的数据安全策略。目前，网络备份管理系统通常采用B／S结构系统，备份节点之间相互独立，备份管理服务器负荷重，在实际应用中容易造成带宽要求高、备份速度慢等缺点。本文提出了基于移动Agent技术的备份管理系统框架，并详细讨论了该框架在实际系统中的设计与实现。实验表明，采用移动Agent技术能够大幅度提高网络
络备份系统的效率。     

A Closed-Loop Automatic Data-Mining Approach for Preventive Network Monitoring

As telecommunication networks grow in size and complexity, monitoring systems need to scale up accordingly. Alarm data generated in a large network are often highly correlated. These correlations can be explored to simplify the process of network fault management, by reducing the number of alarms presented to the network-monitoring operator. This makes it easier to react to network failures. But in some scenarios, it is highly desired to prevent the occurrence of these failures by predicting the occurrence of alarms before hand. This work investigates the usage of data mining methods to generate knowledge from historical alarm data, and using such knowledge to train a machine learning system, in order to predict the occurrence of the most relevant alarms in the network. The learning system was designed to be retrained periodically in order to keep an updated knowledge base.     

Publishers’ relationships on the web: An examination of how publishers’ websites are causing changes in relations in the book industry

This research, funded by the British National Bibliography Research Fund, examined how publishers’ websites are causing changes in relations in the book industry in order to gain further understanding of the implications of the impact of the Internet on the publishing chain. The paper is set within the context of the development of electronic commerce and how business to consumer commerce is now being overtaken by the activity in business to business trading. Publishers have followed the main business trends in using their websites to develop relationships directly with the consumer, but have been rather slower in developing their business to business activity through the Internet. This study investigated what changes were taking place as a result of current publisher activity on the Web and how these changes were affecting the traditional lines of communication in the book industry. An analysis of a range of consumer publishers’ websites was carried out to see what facilities they were offering both to the general public and to business partners within the industry. Questionnaires and interviews were then conducted to establish how publishers, booksellers and wholesalers were using publishers’ websites and whether these sites were beneficial to the industry as a whole. Facilities found on the websites were examined and analysed in order to determine their usefulness and how they might be developed to aid business to business commerce. Additionally, several issues relating to online sales, changes in sales patterns and changes in working methods were discussed. Although an amount of quantitative data is included in the report, many of the issues raised relied on the perceptions and opinions of practitioners in the book trade.     

Historical Trajectories of Innovation and Competitiveness: Hong Kong Firms and their China Linkages

Hong Kong manufacturing firms have been competing in world markets since the 1950’s. Their success has been based on low cost and flexible production and an ability to meet very tight delivery schedules as many of their products are short run fashion items for which consumer demand can be fickle. The opening of China in 1978 has enabled Hong Kong firms to sustain their cost advantages in world markets for a further twenty years. However, the rapid economic development of South China in particular, to which Hong Kong is adjacent, and the competition from lower cost economies in Southeast Asia is leading to pressures on Hong Kong manufacturers to rethink their strategies. Ambitions to continue to compete among world class manufacturers has become a survival strategy. The focus of this paper is to identify and explain the historical development of innovation in the strategies of Hong Kong firms to enable them to continue to dominate niche markets in Europe and the USA and develop a presence in the China market.     

Optimization of the material flow in a manufacturing plant by use of artificial bee colony algorithm

To survive in today’s competitive global market, companies must perform strategic changes in order to increase productivity, eliminating wasted materials, time, and effort. This study will examine how to optimize the time and effort required to supply raw material to different production lines in a manufacturing plant in Juarez, Mexico by minimizing the distance an operator must travel to distribute material from a warehouse to a set of different production lines with corresponding demand. The core focus of this study is similar to that of the Vehicle Routing Problem in that it is treated as a combinatorial optimization problem. The artificial bee colony algorithm is applied in order to find the optimal distribution of material with the aim of establishing a standard time for this duty by examining how this is applied in a local manufacturing plant. Results show that using this approach may be convenient to set standard times in the selected company.     

The ageing process: a challenge for design

Growing interest in the design of products for the over 50s suggests that it is important to assess what we know of older users in relation to product design. An evaluation of the research carried out in this field reveals that changes normally associated with ageing frequently occur in the 30s and 40s. It would appear to make economic sense if products were designed to be used by those with limited abilities as well by as the able-bodied. It is concluded that there are gaps in the research in this area which need to be addressed in order to guide designers in the specifications of products which are functional, efficient, safe and attractive to older and younger users alike.     

Product design, semantics and emotional response

This paper explores theoretical issues in ergonomics related to semantics and the emotional content of design. The aim is to find answers to the following questions: how to design products triggering "happiness" in one's mind; which product attributes help in the communication of positive emotions; and finally, how to evoke such emotions through a product. In other words, this is an investigation of the "meaning" that could be designed into a product in order to "communicate" with the user at an emotional level. A literature survey of recent design trends, based on selected examples of product designs and semantic applications to design, including the results of recent design awards, was carried out in order to determine the common attributes of their design language. A review of Good Design Award winning products that are said to convey and/or evoke emotions in the users has been done in order to define good design criteria. These criteria have been discussed in relation to user emotional responses and a selection of these has been given as examples.     

IT spending in the midst of the Asian economic downturn: a Singapore perspective

The Asian economic downturn has severely affected the revenue and profitability of companies operating in Asia. This has in turn caused a significant number of companies to reduce their spending on IT, particularly in the countries that have been most affected by the downturn. While IT spending is an immediate and visible effect of the downturn, less visible changes in managerial attitudes towards IT, and approaches to controlling IT spending are likely to have longer term implications to the IT capabilities of companies in the region. In this paper, we examine these issues in the Singapore context, paying particular attention to how companies plan to control and reduce IT infrastructure spending. We found that in the participating firms, managers appear to pay more attention to the links between business strategy and IT after the downturn. We also found that deferring investments in physical infrastructure and outsourcing were the main approaches to IT cost reduction.     

Using a fuzzy approach to support financial analysis in the corporate acquisition process

In the global market place, many companies have had to adapt their strategies to meet significant challenges. A strategy adopted by some companies has been international expansion via acquisitions. The need for expert knowledge to determine an appropriate company to acquire has been complicated by the sheer size of the global market place. The costs associated with this in relation to time and personnel have created the need for a computerised expert system to be developed. This paper endeavours to show how a proposed fuzzy based system can assist in the identification of a company for acquisition. The authors discuss the manipulation of the magnitude of fuzzy membership functions to communicate priorities within the system. The fuzzy system is designed to assist financial experts in identifying a suitable company for acquisition in the corporate acquisition process. This includes the deliberate weighting of certain inputs and results above others in the decision-making process. The system attempts to learn and simulate the human precedence given to particular financial statistics in company analysis. The system uses the magnitude of the fuzzy membership functions to reflect the human precedence given to each financial ratio. This enables a particular company's strengths and weakness to be considered while concurrently considering their significance and relevance to the acquiring organisation. The system will enable a larger number of companies to be analysed in a more time and cost-effective manner. The development of this system is intended to illustrate that a fuzzy system can aid the financial experts of an acquiring organisation in the global acquisition process.     

Affinity-Based Network Interfaces for Efficient Communication on Multicore Architectures

Improving the network interface performance is needed by the demand of applications with high communication requirements (for example, some multimedia, real-time, and high-performance computing applications), and the availability of network links providing multiple gigabits per second bandwidths that could require many processor cycles for communication tasks. Multicore architectures, the current trend in the microprocessor development to cope with the difficulties to further increase clock frequencies and microarchitecture efficiencies, provide new opportunities to exploit the parallelism available in the nodes for designing efficient communication architectures. Nevertheless, although present OS network stacks include multiple threads that make it possible to execute network tasks concurrently in the kernel, the implementations of packet-based or connection-based parallelism are not trivial as they have to take into account issues related with the cost of synchronization in the access to shared resources and the efficient use of caches. Therefore, a common trend in many recent researches on this topic is to assign network interrupts and the corresponding protocol and network application processing to the same core, as with this affinity scheduling it would be possible to reduce the contention for shared resources and the cache misses. In this paper we propose and analyze several configurations to distribute the network interface among the different cores available in the server. These alternatives have been devised according to the affinity of the corresponding communication tasks with the location (proximity to the memories where the different data structures are stored) and characteristics of the processing core. As this approach uses several cores to accelerate the communication path of a given connection, it can be seen as complementary to those that consider several cores to simultaneously process packets belonging to either the same or different connections. Message passing interface (MPI) workloads and dynamic web servers have been considered as applications to evaluate and compare the communication performance of these alternatives. In our experiments, performed by full-system simulation, improvements of up to 35% in the throughput and up to 23% in the latency have been observed in MPI workloads, and up to 100% in the throughput, up to 500% in the response time, and up to 82% in the requests attended per second have been measured in dynamic web servers.     

Increased synchrony with increase of a low-threshold calcium conductance in a model thalamic network: a phase-shift mechanism

A computer model of a thalamic network was used in order to examine the effects of an isolated augmentation in a low-threshold calcium current. Such an isolated augmentation has been observed in the reticular thalamic (RE) nucleus of the genetic absence epilepsy rat from the Strasbourg (GAERS) model of absence epilepsy. An augmentation of the low-threshold calcium conductance in the RE neurons (gTs) of the model thalamic network was found to lead to an increase in the synchronized firing of the network. This supports the hypothesis that the isolated increase in gTs may be responsible for epileptic activity in the GAERS rat. The increase of gTs in the RE neurons led to a slight increase in the period of the isolated RE neuron firing. In contrast, the low-threshold spike of the RE neuron remained relatively unchanged by the increase of gTs. This suggests that the enhanced synchrony in the network was primarily due to a phase shift in the firing of the RE neurons with respect to the thalamocortical neurons. The ability of this phase-shift mechanism to lead to changes in synchrony was further examined using the model thalamic network. A similar increase in the period of RE neuron oscillations was obtained through an increase in the conductance of the calcium-mediated potassium channel. This change was once again found to increase synchronous firing in the network.