轻量级嵌入式TCP/IP协议栈的设计

介绍了引入轻量级TCP/IP协议栈的背景，描述了标准TCP/IP协议栈，分析了嵌入式系统中TCP/IP协议栈的特点和设计的思路，总结了轻量级TCP/IP协议栈和标准TCP/IP协议栈的区别。     

基于XML的可配置IP库的设计与实现

当前SOC（System-On-Chip）设计中IP重用面临很多难题：可重用IP的表述及如何提高IP的可重用性等。针对上述的问题，给出一种基于XML描述的IP库设计和实现方法。分析了RTL级IP（Intellectual Property）和IP库的特点，提出了基于XML可配置IP库的层次结构，给出了基于XMLIP库的形式化描述。结合一个软处理器核（OpenRISC嵌入式处理器）给出了基于XMLIP库的框架及实例，总结了基于XML可配置IP库的特点，介绍了基于XMLIP库在实验室项目中的应用：一个基于CSCWD（计算机协同工作设计）的SOC开发设计平台。     

IP数据包及其应用开发

描述了ICP／IP协议的基本结构及IP数据包的一种操作方法，探讨了网络层的应用开发。     

基于Java技术的BACnet/IP路由器的软件实现

对BACnet／IP网络体系结构和BACnet／IP互联网拓扑结构进行了分析．描述了BACnet／IP路由器的功能．提出了连接多个BACnet／IP网络的路由器软件要解决的关键技术问题，论证了Java技术用于开发BACnet／IP路由器软件的可行性．完成BACnet／IP路由器软件的实现。     

基于多播技术的网络应用

在介绍IP多播技术基本原理的基础之上，重点阐述了在Linux环境下如何利用多播技术实现数据的广播和监听，并简要地描述了IP多播技术的应用情况。     

移动IP穿越NAT网关的研究与实现

在分析移动IP隧道数据包和NAT一起工作会出现问题的基础上，描述了基于IP-in-UDP隧道(简称UDP隧道封装)封装移动IP穿越NAT的解决机制，并给出了在企业虚拟专用网中移动IP穿越IPSec／NAT集成网关的一种实现。     

宽带IP数据包分类方法

IP over DH是当前IP主干网上普遍采用的传输技术，与其他传输方式相比，它能提供较高的带宽利用率。本文简要描述了IP over SDH的原理及解帧过程，介绍了SATURN开发组制定的POS-PHY系列接口，并分析了基于第三层和第四层的分类模型。     

嵌入式协议栈Mobile IP功能的测试

在一个无操作系统的嵌入式系统上移植了标准的ICP／IP协议栈。并为协议栈添加了对Mobilc IP协议的支持，为了检验所作的修改是否符合Mobile IP协议的规定，进行了多项测试，观察协议栈在不同情况下的反应，文章对测试过程进行了描述并列出了测试条目。     

IP交换机中关键软件的研究与实现

IP交换机是宽带高速智能网络中的重要设备，本文综合对比了几款IP交换机，给出了IP交换机中的一般软件结构．对软件中最为关键的操作系统、路由软件和驱动程序作了详细的分析．并在此基础上阐述了选择、设计的一般方法，以LT-501IP交换机的设计实现为实例，描述了重点函数和功能模块的设计实现的算法和流程．     

基于Ponder语言的防火墙策略描述方法研究

目前Ponder语法一般采用域表达式来标识主体和目标,不支持IP这类特殊类型的主体/目标标识.而防火墙的策略描述一般用IP地址来标识,如何扩展Ponder语法,使其可以表达防火墙的访问控制规则,是目前用Ponder语言描述防火墙规则亟待解决的问题.引进IP域和服务域结构,给出了采用IP数据包标识目标的描述方法.     

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.     

A comparison of models for fusion of the auditory and visual sensors in speech perception

Though a large amount of psychological and physiological evidence of audio-visual integration in speech has been collected in the last 20 years, there is no agreement about the nature of the fusion process. We present the main experimental data, and describe the various models proposed in the literature, together with a number of studies in the field of automatic audiovisual speech recognition. We discuss these models in relation to general proposals arising from psychology in the field of intersensory interaction, or from the field of vision and robotics in the field of sensor fusion. Then we examine the characteristics of four main models, in the light of psychological data and formal properties, and we present the results of a modelling study on audio-visual recognition of French vowels in noise. We conclude in favor of the relative superiority of a model in which the auditory and visual inputs are projected and fused in a common representation space related to motor properties of speech objects, the fused representation being further classified for lexical access.     

在结构与随机扰动下的大系统的稳定性

在本文中,我们给出了在结构与随机扰动下的动态大系统的稳定性分析,建立了这类大系统的依概率吸引性,依概率一致有界性,依概率大范围渐近稳定性,p吸引性,一致p有界性,和大范围渐近p稳定性的结论。这些结论的假设是由孤立子系统和与其联系的李亚普诺夫函数,受扰系统的结构和作用在子系统上的随机扰动表出的。     

关联规则挖掘技术研究进展*

为帮助人们深入研究关联规则挖掘技术,总结了关联规则的分类方法、评价方法以及相关技术的最新进展,特别是对关联规则的主要算法进行了详细的介绍,并探讨未来的发展方向。该研究比较系统全面,对将来进一步深入分析关联规则挖掘技术具有指导意义。     

The Old-Age Healthy Dependency Ratio in Europe

The aim of this study is to answer the question of whether improvements in the health of the elderly in European countries could compensate for population ageing on the supply side of the labour market. We propose a state-of-health-specific (additive) decomposition of the old-age dependency ratio into an old-age healthy dependency ratio and an old-age unhealthy dependency ratio in order to participate in a discussion of the significance of changes in population health to compensate for the ageing of the labour force. Applying the proposed indicators to the Eurostat's population projection for the years 2010-2050, and assuming there will be equal improvements in life expectancy and healthy life expectancy at birth, we discuss various scenarios concerning future of the European labour force. While improvements in population health are anticipated during the years 2010-2050, the growth in the number of elderly people in Europe may be expected to lead to a rise in both healthy and unhealthy dependency ratios. The healthy dependency ratio is, however, projected to make up the greater part of the old-age dependency ratio. In the European countries in 2006, the value of the old-age dependency ratio was 25. But in the year 2050, with a positive migration balance over the years 2010-2050, there would be 18 elderly people in poor health plus 34 in good health per 100 people in the current working age range of 15-64. In the scenarios developed in this study, we demonstrate that improvements in health and progress in preventing disability will not, by themselves, compensate for the ageing of the workforce. However, coupled with a positive migration balance, at the level and with the age structure assumed in the Eurostat's population projections, these developments could ease the effect of population ageing on the supply side of the European labour market.     

Spatio-temporal distribution of rice phenology and cropping systems in the Mekong Delta with special reference to the seasonal water flow of the Mekong and Bassac rivers

Multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS) data was used to estimate the spatial distribution of heading date and rice-cropping system employed in the Mekong Delta relative to seasonal changes in water resources in 2002 and 2003. We improved a Wavelet-based Filter for determining Crop Phenology (WFCP) and developed a Wavelet-based Filter for evaluating the spatial distribution of Cropping Systems (WFCS) to the interpretation of MODIS time-series data to determine the spatial distribution of rice phenology and various rice-cropping systems from the seasonal Enhanced Vegetation Index (EVI) data. The findings correspond well the physical characteristics of the cropping system in the Mekong Delta, which have changed over time in response to localized and seasonal changes in water resources. One such example is the double-irrigated rice-cropping system commonly employed in the upper Mekong Delta in the dry season to avoid damage due to the subsequent floods. The shortage of suitable irrigation water and intrusion of saline water in the coastal regions during the dry season has constrained the practice dry-season cropping and has meant that the double- and single-rainfed rice-cropping systems are employed in the rainy season. A triple-irrigated rice-cropping system is used in the central part of the Mekong Delta which is located midway between the flood-prone and salinity intrusion areas. Analysis of annual changes in the rice cropping systems between 2002 and 2003 showed that the triple-cropped rice expanded to the flood- and salinity-intrusion areas. This expansion indicates that the implementation of measures to limit the extent of flooding and salinity intrusion by improved farming technologies and improvements in land management. The heading dates in the upper Mekong Delta in 2003 were earlier than in 2002 by approximately 20 to 30 days. The reasons for this would be due to decreased flood runoff in 2002 compared to 2001, and implementation of government policies regarding early sowing of dry-season crops. Subsequent analysis of the MODIS data confirmed that the spatial distribution of rice-cropping systems was closely related to seasonal changes in river runoff regime in the Mekong Delta.     

Desktop publishing in education

Abstract The term 'desktop publishing' has received much media coverage in recent months in both the commercial and educational press. School-based 'desktop publishing' packages are at the moment poor imitations of full-specification systems. This paper discusses the state of desktop publishing in education today and demonstrates the weaknesses of the systems available for use in the classroom. The skills required for desktop publishing are interrelated in a complex way and cannot be presented in a hierarchical fashion. A model of the functional processes involved is suggested in the paper and analysed in terms of the skills required.     

A distributed deadlock detection and resolution algorithm and itscorrectness proof

The key idea of the algorithm is to let one transaction controller be in charge of all transactions in a set of interacting transactions. Two transactions are interacting if they are both interested in (accessing) the same resource. In addition, the controller is in charge of all the resources allocated to any of the transactions in the set. Having one controller in charge of all the transactions in a set of interacting transactions and all the resources allocated to them makes it easier to detect deadlocks and avoid them. The main problem dealt with is how a controller takes charge of another transaction when the transaction tries to access one of the resources currently in the control of the controller and how a controller releases a transaction back to its original controller when the transaction is no longer interested in any of the resources in which one or more of the other transactions are also interested. Communicating sequential processes (CSP) is used to code the algorithm. The correctness of the algorithm is proved in a semiformal manner     

Adaptive solutions to the mutual exclusion problem

Summary Algorithms for mutual exclusion that adapt to the current degree of contention are developed. Afilter and a leader election algorithm form the basic building blocks. The algorithms achieve system response times that are independent of the total number of processes and governed instead by the current degree of contention. The final algorithm achieves a constant amortized system response time. Manhoi Choy was born in 1967 in Hong Kong. He received his B.Sc. in Electrical and Electronic Engineerings from the University of Hong Kong in 1989, and his M.Sc. in Computer Science from the University of California at Santa Barbara in 1991. Currently, he is working on his Ph.D. in Computer Science at the University of California at Santa Barbara. His research interests are in the areas of parallel and distributed systems, and distributed algorithms. Ambuj K. Singh is an Assistant Professor in the Department of Computer Science at the University of California, Santa Barbara. He received a Ph.D. in Computer Science from the University of Texas at Austin in 1989, an M.S. in Computer Science from Iowa State University in 1984, and a B.Tech. from the Indian Institute of Technology at Kharagpur in 1982. His research interests are in the areas of adaptive resource allocation, concurrent program development, and distributed shared memory.A preliminary version of the paper appeared in the 12th Annual ACM Symposium on Principles of Distributed ComputingWork supported in part by NSF grants CCR-9008628 and CCR-9223094     

日汉机器翻译中词的自动切分技术

本文阐述NDJCMT系统中词的自动切分技术, NDJCMT是我们实现的一个日汉机器翻译实验系统, 词的自动切分是日语词素分析、句法及语义分析的基础, 是一项日本语计算机信息处理的基础性研完课题, 它涉及对语言本身的研究。日语和汉语类似, 词及词之间无分隔符, 通常假名、汉字混写, 给词的切分造成了困难。作者根据日语的特点, 提出了一种“ 句节数最少” 词的自动切分方法, 使用语言编程且在一机上获得实现。