Domain Dynamics poised to take centre stage

Following the recent injection into Domain Dynamics of $3 million, (News, p.8) the smart card industry will hear a lot more from the UK-based intellectual property company in 2002.     

Performance analysis of Virtual Mobility Domain scheme vs. IPv6 mobility protocols

The population of mobile users seeking connectivity to the Internet has been growing over the years, spurred by the capabilities of handsets and the increasing rich Internet content and services. Mobility management to enable efficient Internet access for users on the move is thus gaining significance. IETF has standardized several protocols such as Mobile IPv6, Hierarchical Mobile IPv6, and Proxy Mobile IPv6 to provide mobility management on the IP network. With future Internet design initiatives gaining momentum, it is important that these initiatives consider mobility management as an integral part of the design. In this article, we introduce the concept of Virtual Mobility Domain and describe the main features and key strengths of Virtual Mobility Domain that are designed to provide mobility management in a newly proposed tiered Internet architecture. Instead of IP addressing, the proposed Virtual Mobility Domain uses a tiered-addressing scheme to identify a mobile node with a single address regardless of its location. The tiered addressing provides a dynamic address length which brings less signaling overhead and scalable management. We also propose a collaborative network-based mobility management mechanism to provide low-latency handoffs and less processing-overhead on the mobile node compared to the IPv6-based protocols. The proposed mobility scheme unifies inter and intra-domain mobility management by introducing common anchor cloud concept which provides a distributed management and seamless mobility experience. We present comparative qualitative and quantitative performance analysis of Virtual Mobility Domain and aforementioned IPv6-based mobility protocols for Intra-AS roaming support. We examine handoff latency and signaling overhead performance of each protocol based on numerical results retrieved from analytical models and OPNET modeler based simulations. The results from a comparative performance study show the potential for more efficient mobility management under the proposed Internet architecture.     

Efficient parallel algorithm for statistical ion track simulations in crystalline materials

We present an efficient parallel algorithm for statistical Molecular Dynamics simulations of ion tracks in solids. The method is based on the Rare Event Enhanced Domain following Molecular Dynamics (REED-MD) algorithm, which has been successfully applied to studies of, e.g., ion implantation into crystalline semiconductor wafers. We discuss the strategies for parallelizing the method, and we settle on a host-client type polling scheme in which a multiple of asynchronous processors are continuously fed to the host, which, in turn, distributes the resulting feed-back information to the clients. This real-time feed-back consists of, e.g., cumulative damage information or statistics updates necessary for the cloning in the rare event algorithm. We finally demonstrate the algorithm for radiation effects in a nuclear oxide fuel, and we show the balanced parallel approach with high parallel efficiency in multiple processor configurations.     

A mobile-based solution for supporting end-users in the composition of services

Currently, technologies and applications evolve to create eco-systems made up of a myriad of heterogeneous and distributed services that are accessible anytime and anywhere. Even though these services can be used individually, it is their coordinated and combined usage what provide an added value to end-users. In addition, user’s wide adoption of mobile devices for daily activities have fostered a shift in the role played by end-users towards Internet data and services. However, existing solutions to service composition are not targeted to ordinary end-users. More easy-to-use tools have to be offered to end-users to make sure that they are successfully accepted and used by them. To this end, the work presented in this paper supports end-users in the creation of service compositions by using mobile devices. We present a Domain Specific Visual Language (DSVL) for end-users that allows them to create service compositions. A tool specifically designed for mobile devices supports this DSVL.     

What’s in a name. . . generator?

Domain generation algorithms can be used for registering spamming and phishing sites, as well as by botnets for domain flux. In this paper we study Kwyjibo, a more sophisticated domain/word generation algorithm that is able to produce over 48 million distinct pronounceable words. We show through four different implementations how Kwyjibo might be deployed and how its size can be reduced to under 163KiB using a technique we call ??lossy distribution compression??. This means that Kwyjibo is both powerful as well as small enough to be used by malware on mobile devices.     

基于QoS域代理在移动无线互联网中区分服务的设计与实现

随着用户数和应用业务的快速发展,对新一代Internet的服务质量提出了更高的要求。然而,在Internet中引入无线接入方式使得提供QoS面临更大挑战。文章基于区分服务(DiffServ)框架结构,并结合移动管理协议———移动IP(MobileIP)协议来研究和解决如何在新一代移动无线互联网中提供QoS控制。同时在每个自治域中引入一个新的概念———QoS域代理(QoSDomainAgent,QDA),并利用QDA进行资源管理并参与和移动主机/用户(MobileHost,MH)或其它QDA进行动态SLS的协商,同时采用组播方式把QDA中的QoSSLS内容信息传输给域内的每一个第一跳和边界路由节点。通过对相关协议和功能进行必要的修改和扩充,从而有效地解决了MH和网络的动态服务级别协议(SLA)的协商和在MobileIP切换中各入口节点动态建立SLS的问题,同时可以有效减少信令交互,节省无线资源和减少移动终端的电池消耗,并且有利于MH在域内漫游时进行无缝切换。最后给出作者的结论及进一步的研究内容。     

移动IP技术及Dynamics HUT Mobile IP应用研究

移动IP是一种解决因特网上节点移动性问题的技术，也是目前Internet技术的一个研究热点。文中从移动IP的基本概念和原理人手，对国内外移动IP在Linux操作系统和Windows操作系统上的实现状况做一概述，并对IPv4下的DynamicsHUTMobileIP系统在Linux平台上安装、配置和应用程序的测试作了详细的阐述，为进一步研究移动IP技术的各项技术打下基础。     

基于领域知网的垃圾邮件过滤方法

垃圾过滤技术的一个重要指标是误判率。把用户的一封正常邮件误判为垃圾邮件,其损失更大。领域知网是某领域内的知识库。提出为常见垃圾邮件类别建立领域知网,当遇到难判别的邮件时,使用基于领域知网的过滤技术,可以降低垃圾邮件的误判率。还介绍了构建领域知网的方法,以及其他关键技术。     

Comparing free algebras in Topological and Classical Domain Theory

We compare how computational effects are modelled in Classical Domain Theory and Topological Domain Theory. Both of these theories provide powerful toolkits for denotational semantics: Classical Domain Theory having been introduced by Scott, and well established and developed since; Topological Domain Theory being a generalization in which topologies more general than the Scott-topology are admitted. Computational effects can be modelled using free algebra constructions, according to Plotkin and Power, and we show that for a wide range of computational effects, including all the classical powerdomains, this free algebra construction coincides in Classical and Topological Domain Theory, when restricted to countably-based continuous domains.     

Performance analysis of DNS-assisted global mobility management scheme in cost-optimized proxy mobile IPv6 Networks

Proxy Mobile IPv6 (PMIPv6) is designed to provide a network-based localized mobility management protocol, but it does not handle the global mobility of hosts. In this paper, we propose a location management scheme based on Domain Name System (DNS) for PMIPv6. In this proposed scheme, DNS as a location manager provides PMIPv6 for global mobility. In addition, a paging extension scheme is introduced to PMIPv6 in order to support large numbers of mobile terminals and enhance network scalability. To evaluate the proposed location management scheme, we establish an analytical model, also formulate the location update and the paging cost, and analyse the influence of the different factors on the total signalling cost. The performance results show how the total signal cost changes under various parameters.     

采用面向对象技术的领域工程

面向对象技术是应用工程中成熟的主流技术。领域工程为应用工程提供了领域构件和领域构架,所以在很大程度上支持了软件复。采用面向对象技术的领域工程将提供更多的软件复用。     

Dynamics and Cooperative Object Manipulation Control of Suspended Mobile Manipulators

Dynamics and control of mobile manipulators is obviously a more challenging problem compared to fixed-base robots. Including a suspension system for these mobile platforms increases their maneuverability, but considerably adds to their complexity. In this paper, a suspended wheeled mobile platform with two 6-DOF Puma-type manipulators is used to manipulate an object along a given path. To apply a model-based control algorithm, it is required to have an explicit dynamics model for such highly nonlinear system. This model should be as concise as possible to include fewer mathematical calculations for online computations. Therefore in this paper, a detailed set of dynamics equations for a multiple arm wheeled mobile platform equipped with an effective suspension system is presented. The method is based on the concept of Direct Path Method (DPM), which is extended here for such challenging type of robots. The obtained dynamics model is then verified with a dynamical analysis study using software ADAMS. Then, Natural Orthogonal Complement Method is used to include the non-holonomic constraint of the wheeled platform in a more concise dynamics model. Next, an impedance control law is applied for cooperative manipulation of an object by the two manipulators. The obtained results for a suspended wheeled platform equipped with two 6-DOF Puma-type manipulators reveal a successful performance for moving an object along a mixed circular-straight path, even in the presence of unexpected disturbing forces, system/end-effector flexibility and impacts due to contact with an obstacle.     

基于OPS的计算流体力学软件多平台自动并行

当前高性能计算机体系结构呈现多样性特征,给并行应用软件开发带来巨大挑战.采用领域特定语言OPS对高阶精度计算流体力学软件HNSC进行面向多平台的并行化,使用OPS API实现了代码的重构,基于OPS前后端自动生成了纯M PI、OpenM P、M PI+OpenM P和M PI+CUDA版本的可执行程序.在一个配有2块I...     

一种用于微型工厂的毫米级全方位移动微机器人设计与分析

介绍了一种毫米级全方位移动微机器人,尺寸为9mm*8mm*8mm。独特的双轮设计实现了转向时与地面的滚动摩擦。驱动器为3个直径2mm的电磁微马达,其中2个用于直线驱动,另一个用于转向。运动受力分析揭示了微马达驱动力矩与双轮结构尺寸及各种摩擦之间的关系。仿真计算及实验表明微机器人具有良好的负载能力,能够满足微型工厂中的搬运操作要求。     

基于域数据模型的类SQL查询语言

基于域数据模型,提出了一种类SQL的域数据库查询语言DSQL.DSQL提供了对域数据库进行各项操纵和管理的功能.通过分析域数据模型,给出了DSQL设计的总体思路,描述了DSQL的分类、语法设计和访问控制方法.最后通过具体的查询示例说明了DSQL的用法.     

域名服务体系安全问题研究

域名服务是互联网的基础服务。域名服务体系不同于域名系统（DNS）,仅提高域名系统的安全并不能解决整个域名服务的安全问题。基于中国互联网络信息中心运行国家CN域名的经验,创新的提出域名服务体系的概念,并对域名服务体系的安全问题进行了论述分析。首先介绍了域名系统的基础知识及全球域名体系,然后研究分析了域名服务体系中的5个主要角色和7个主要数据流,结合数据流分析了其中主要的安全问题,并提出了安全防范措施。     

基于知识的UML图形文档自动生成

基于领域本体的需求获取使得用领域术语描述用户需求,并进行应用模型的自动分析成为可能,以尽可能地保证需求描述的正确性和完整性。从以领域概念为背景的应用模型,到以软件概念为基础的应用软件模型,是需求工程要完成的一个实质性跨越。UML是目前软件需求描述的一个实际上的标准。该文主要论述了从基于领域本体的应用需求描述到基于UML的软件需求文档的自动转换过程,文章提出建立从领域本体概念到UML概念映射规则库,以及根据UML概念填写用XML表示的UML图元模板的规则库,设计并实现了一个基于规则的,从应用需求概念到UML图元模板的自动转换工具。     

Data warehouse access using multi-agent system

The new approach that we will propose, in this paper deals with the dynamic data distribution of the data warehouse (DWH) on a set of servers. This distribution is different from the “classical” one which depends on how data is used. It consists in distributing data when the machine reaches its storage limit capacity. The proposed approach insures the scalability and exploits the storage and processing resources available in the organization using the DWH. It is worth noting that our approach is based on a multi-agent model mixed with the scalability distribution proposed by the Scalable Distributed Data Structures. Our multi-agent model is made up of stationary agent classes: Client, Dispatcher, Domain and Server, and a mobile agent class: Messenger. These agents collaborate and achieve automatically the storage, splitting, redirection and access operations on the distributed DWH. In this paper, we focus on the global dynamic for the data access operation and we present the inherent experimental results.     

The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications

The IP Multimedia Subsystem (IMS) is defined by the 3 ^rd Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services. Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype application. This work was done when the author was with Siemens Communications Inc., Boca Raton, FL