面向Java语言的代码安全

Java语言是一种面向网络的编程语言,通过网络下载Java代码并在本地系统执行是经常的事,但这样可能会危及本地系统安全。虽然Java语言提供了安全编程环境,但是它并没有提供一个完善的下载、运行代码的安全系统。本文以Java安全体系结构为中心详细介绍了Java语言主要安全特性和技术,给出了一种新型的解决网络环境中Java代码安全问题的系统,该系统应用类封装技术实现精细安全策略的安全策略编辑器。     

CORBA和移动代理在电信网络管理中的应用研究

对CORBA和移动代理技术进行了深入研究，在分析了两种网管技术的优势和不足的基础上．提出了一个基于CORBA和移动代理技术的综合网管模型。网管模型利用Java虚拟机作为运行平台．ORB作为底层通信设施，根据网络规模对两种网管模式性能的影响，在不同网管任务中分别使用CORBA对象和移动代理。     

综合网管中通用接口平台的研究和设计

介绍国内目前多厂商环境下通信网络的管理现状以及通信网划分为若干专业子网导致的问题。概述综合网管在网络管理中的作用以及网关接口在综合网管体系结构中的地位和重要性。综合网管是未来网络管理的趋势,而接口平台则是综合网管的根基部分。分析了目前存在的各种网管系统的接口和子网管系统接口的通信协议,指出导致多种接口协议长期存在并共同发展的原因。阐述开发一个通用的接口平台来对各种接口协议的整合和适配的必要性和实用价值。在对实际开发中的综合网管系统过程中,抽象出一个综合网管框架结构,并在此基础上给出一个通用接口平台的架构和具体的设计。     

OSA-based service platform for all-IPv6 network environments

The use of IP (Internet protocol) technology in the information and communications industry constitutes a major global trend. A highly efficient service architecture, enabling technologies and advanced applications are essential to rapid multimedia services in an all-IPv6 network environment. This work presents an all-IPv6 service platform based on open service architecture (OSA) to support a set of standard interfaces and applications. The all-IPv6 network environment was integrated using a network-processor-based IPv4/IPv6 translator and a mobile router (MR) supported IPv6 network mobility. The feasibility of the open service platform for all-IPv6 network environments and of the designed application programming interfaces was examined using three applications: e-commerce, video-on-demand, and on-line gaming. The performance analysis indicates that the system throughput increased from 10.5 to 60.5 Mb/s as the number of users increased from 1 to 80; the mean response time increased from approximately 1 to 10.5 ms, and the delay time increased from 0.1 to 1 ms.     

The common RRM approach to admission control for converged heterogeneous wireless networks

As the wireless environment becomes ever more populated and complex, individual networks offering single or restricted services will become ever more uncompetitive. Common radio resource management algorithms and strategies are used in heterogeneous or converged wireless networks to integrate multiple physical radio interfaces to support different levels of data rates, mobility, and traffic. Admission control in a common RRM environment is used to select the most appropriate wireless access based on service type, user preference, and network load. This is used to provide a balance between real-time and non-real-time traffic across the available access technologies. The development of common radio resource management strategies requires a suitable platform of coupled access networks and is the motivation behind the development of a converged wireless test platform. The tightly coupled platform supports voice and data call setup and delivery over UMTS and WLAN     

Design of a system software based on a Java SoC processor

Java technology is spreading rapidly all over the world in recent years. It is a popular application development language for its well-encapsulation, platform-independent and high security. There are great amounts of Java games and other gadgets on mobile platforms, as well as on set-up-box systems. As Java applications become more sophisticated, the Java Virtual Machine (JVM) middle-wares in embedded systems are not satisfying, Java-specific chips extend in the market. All existing Java-based system software or Operating System (OS) are used on JVM, they cannot be used on Java processors. It is important to develop a pure Java system software or OS so that embedded systems using Java processors will have great performance in Java applications. This paper presents a set of system software designed for a Java-specified processor VP6K, which is also a System-on-Chip (SoC). This system software includes real-time multitask dispatching, file management, device management, hardware drivers, and infrastructural Application Programming Interface (APIs). According to experimental results, the system software provides interfaces for Java programs to fully handle CPU resource, so that all applications can be executed properly and efficiently. VP6K embedded platform shows its good performance for Java applications when the system software is implemented.     

JTMN: a Java-based TMN development and experimentationenvironment

Java technology has largely entered the world of element, network, and service management and has undoubtedly proven useful in combination with the SNMP framework for both manager and agent side developments. However, very few experiments have been made so far trying to provide an in-depth integration of this technology within the TMN framework. In this paper we present a free software which offers a generic environment which provides a basis for reaching this integration. This environment, called J^TMN, is composed of a set of Java software packages which enable both development and deployment of TMN compliant components. Not bound to any specific management platform and easily portable to any TMN system, its goal is to allow experimentation and deployment of more advanced features such as mobile agents, active network management, and advanced delegation in harmony with existing TMN approaches     

网络攻防模拟实验平台的设计与实现

针对网络攻防环境难以构建的难题,提出了基于虚拟环境的网络攻防模拟实验平台,给出了模拟实验平台的组成结构,分析了在该平台上开展网络攻防模拟实验过程和系统运行机制。分别对网络攻击子系统和网络防护子系统进行了详细设计,研究了两个子系统中采用的关键技术及实现方法。通过采用虚拟机技术,在服务器上虚拟出网络攻击和网络防护子系统,能够实现当前绝大多数的网路攻击操作以及网络防护的配置管理,能够为用户提供功能更为全面、性能更为优越、仿真程度更为逼真的网络攻防实验训练环境。     

Ubiquitous Information Services with JAIN Platform

To provide responsive information services in a ubiquitous computing environment, service software and system development are indispensable. A component-based ubiquitous information system with a JAIN (Java APIs for Integrated Networks) platform to achieve seamless transmissions and reach-everywhere communications was designed in our research. In this development, numerous ubiquitous service modules were identified: location management, roaming, mobile IP and WAP networking. These component-based network modules were constructed using a component composition language with component specification and interface definition, running on top of a distributed service architecture using a JAIN platform to distribute the ubiquitous information services to mobile users. Two applications, Wireless-Application-Protocol (WAP) Mail and Video-on-Demand (VoD) services, show that the JAIN-like platform with the developed networking components effectively fills the gap for application developers between mobile appliances and various kinds of ubiquitous information services.     

Masterpiece: physical interaction and 3D content-based search in VR applications

Virtual reality interfaces can immerse users into virtual environments from an impressive array of application fields, including entertainment, education, design, and navigation. However, history teaches us that no matter how rich the content is from these applications, it remains out of reach for users without a physical way to interact with it. Multimodal interfaces give users a way to interact with the virtual environment (VE) using more than one complementary modality. Masterpiece (which is short for multimodal authoring tool with similar technologies from European research utilizing a physical interface in an enhanced collaborative environment) is a platform for a multimodal natural interface. We integrated Masterpiece into a new authoring tool for designers and engineers that uses 3D search capabilities to access original database content, supporting natural human-computer interaction.     

利用Java实现一个非线性规划问题

Java自发布以来 ,作为一种面向对象的程序设计语言深受广大计算机业者的青睐。而Java2的出现使得支持应用程序开发的环境日益成熟 ,表现在超强的数据处理能力与网络集成开发能力 ,以及由于其跨平台能力和可移植性所带来人机交互能力与分布式计算能力。正是由于后者 ,给出一个非线性规划算法解决一个飞行管理问题。     

一种专用网络管理平台的设计思路

文中分析了网络管理平台的现状、发展趋势和特点.根据笔者的实践从网络管理平台的体系结构与组成,模块之间的通信和二次开发工具等方面,给出了一种专用网络管理平台的设计思路;阐述了实现网络管理平台的3个关键技术:平台体系结构技术、网络管理协议适配技术和网管信息呈现技术关键技术.目前,该设计方案已经应用于多个项目中.     

Study of the Security in Network Management Based on Mobile Agents

Security of mobile-agent based network management must be considered due to the widespread adoption of mobile agents in network management, which involves the protections of mobile agents, management station and managed devices. The integrated security model proposed in our paper incorporates the effective security countermeasures of these entities into a trusted execution environment and two security protection layers. Sandbox based on Java virtual machine and Java card independent on the network devices also with the cryptography technology in this model together protect the network management process.     

大型企业信息化应用系统网络平台研究

信息化网络平台是信息化应用系统的基础,通过对信息化网络平台的研究,可以了解和掌握其组成和必要的关键技术,提供良好的网络平台,从而提升应用系统的使用品质,为使用者带来更顺畅的感受。在网络平台的关键技术研究中,通常可以通过搭建临时的实验室环境,对关键技术进行部署和配置,从而取得高可用性、高可靠性和高安全性等特性。文中通过一些已取得成功经验的大型企业信息化应用系统网络平台的研究,列举出了一些关键技术,可以较好地指导其他企业信息化应用系统网络平台的建设。     

Android平台的即时通信系统客户端设计方案

为解决在基于Linux操作系统的Android手机平台上即时通信问题,实现在系统客户端进行文本、图片、音乐的传送和播放。采用Java语言环境下Android应用开发工具和API接口,并使用Eclipse加上Android集成开发环境插件为手段,对客户端架构、应用模块框架、数据存储、主要功能和核心模块开发技术等全方面分析,从而提供了实现即时通信系统的客户端解决方案。     

Experimentation-oriented platform for development and evaluation of MANET cross-layer protocols

We introduce a platform that simplifies the development, performance evaluation, and comparison (DEC) of cross-layer protocols for multi-hop ad hoc networks (MANET). To the best of our knowledge, this is the first platform that provides an integrated API for controlling and assessing, on a per-packet basis, the physical layer and MAC/LLC parameters (e.g. frequency channel, power, rate, coding/modulation, fragmentation, number of retransmissions) for IEEE802.11 network interfaces.Today, performance evaluation of wireless mobile ad hoc networks heavily relies on simulation, which is limited in reflecting real environment scenarios due to the channel modeling approximations. Experimental comparisons of protocols in real-world propagation environment are difficult because of limited reproducibility of the channel propagation, environment, and mobility scenarios. We introduce a DEC platform that provides a network virtualization above the physical/link layers. It runs multiple protocols in TDMA-like timeslots guaranteeing an equitable share of the medium, seamless switching between protocols and synchronization between the nodes, all in a transparent fashion to developers. An extensive experimental evaluation demonstrates the usefulness of the platform.     

Grails框架在数字电视用户管理系统中的应用

Java EE是目前使用最为广泛的Web应用开发平台,然而,Java EE包含了一套非常复杂的规范,不容易学习掌握且开发效率较低,虽然网络社区内不断出现的各种基于Java EE的开源框架从一定程度上弥补了这种不足,但仍不能够使人满意。针对这一情况,介绍了一种新的开源框架Grails,并通过其在数字电视用户管理系统中的应用,以实例说明了Grails框架为开发人员带来的便利和工作量的极大的节省。     

基于Java虚拟机的开放式交互数字电视平台的构建

从计算机网络技术的角度 ,分析交互式数字电视平台的构建必须以开放的Java网络技术为基础 ,构建Java虚拟机 ,在Java虚拟机的基础上 ,以标准中间件作为应用接口 ,构建丰富多彩的交互式数字电视应用平台     

Adaptive connectivity management middleware for heterogeneous wireless networks

The trends of network convergence and mobile accessibility in the Internet are bringing new challenges to the connectivity management of end hosts. Concerning network convergence, the configuration of heterogeneous access networks should be taken into consideration. As for mobile accessibility, seamless handoff between diverse access points is a challenging issue. This article presents the design and implementation of connectivity management middleware (CMM), a channel-based architecture for context-aware connectivity management. This architecture can both provide network awareness to applications and manage network resources in an adaptive fashion. In the case of network awareness, the platform provides interfaces for applications to query network QoS and availability status, as well as subscribe connection events. As for adaptive resource management, channel-based transport services for seamless access switching and disconnection treatment are provided based on a policy mechanism. A prototype is implemented with which experiments were performed in a GPRS-WLAN integrated environment in order to demonstrate the operational correctness of the architecture. Performance metrics are measured and analyzed.     

基于云计算的工业互联网数据资源管理平台构建

云计算作为一种新兴的商业计算模型,融合了分布式计算、并行计算、效用计算等计算机技术与网络技术的优势,为互联网络提供了一个安全、可靠的运行环境。为推进工业互联网平台的自动化、智能化、数字化、网络化发展,技术人员将云计算技术与工业互联网数据资源管理平台的构建工作融为一体,旨在发挥云计算模式低成本、高效率与高可用性的应用优势,以增强工业互联网平台的安全性、可靠性与稳定性。基于此,文中着重围绕基于云计算的工业互联网数据资源管理平台的构建思路展开了论述,以此来强调云计算技术在平台构建过程中的重要作用。