浅谈软交换系统应用中的优势与不足

随着通信技术的不断发展,软交换技术由于其自身的一系列的优势,因此被广泛用于电信网络。软交换技术极大的促进了电信交换网络的发展,但是在实际的应用当中也并非尽善尽美,还存在一些不足。文章对软交换系统在实际应用中的优势进行了阐述,并对其不足之处进行了相应的探讨。     

河北联通NGN通信网络的设计与实施

本文研究了河北联通NGN通信网的网络架构方案，重点对“负荷分担双归属”的软交换组网模式、信令组网和业务工单组网的设计和实施等问题进行了论述。     

基于软交换的边缘接入网关的设计探析

随着网络技术的高速发展,传统的PSTN网络系统已经不能满足人们的需求,随着即时通信等新技术的应用,新一代的NGN网络逐渐发展起来,NGN网络是统一整合了信令网关、智能终端、媒体网关以及媒体服务器等内容,虽然近年来得到了很快的发展,但是仍然存在着一些问题,其中比较突出的一点就是基于软交换平台的用户接入问题。本文结合笔者多年工作经验,对基于SIP协议的软交换平台和网关设计方案进行了初步探讨,以期为同行提供一定的参考。     

IP软交换承载网技术在联通网络中设计与应用

IP软交换承载网是以IP技术为核心,承载数据、语音、视频等多业务的软交换承载网络。为了满足未来几年联通业务网IP化演进时对IP承载的需求,支撑长期的软交换、3G、IMS等网络的演进和基于IP的通信级公众数据业务的开展需要建设一张基于IP的软交换承载网。因此,将IP软交换承载网规划设计的思考过程和涉及到的关键技术进行阐述和归纳。     

软交换网络技术的应用和未来趋势

本文介绍了软交换技术的功能和软交换网络的基本概念，研究了软交换网络的框架结构、相关协议、特点，探讨了软交换网络发展前景。     

浅谈软交换技术的应用与发展

本文简要阐述软交换技术的概念,及在语音长途和网络智能化改造中的应用,并进一步展望其发展空间。     

探讨如何将基于IP的电路交换网络与软交换核心网的相融合

现阶段有关3g互联网网络的发展方向应当集中表现在：将软交换技术与ip网络结构相融合的网络运行系统。因此，研究两者之间的融合技术以及融合方式是至关重要的。基于此，本文以3g网络的发展为研究对象，提出了一种建立在ip电路交换网络基础之上，实现3g核心网发展的基本方案，同时实现了电路交换网络与软交换核心网之间的充分融合，实践证实能够取得良好的效果。     

基于消息的即时协作聚合平台的研究与应用

基层班组信息系统优化提升是为信息系统助力基层减负的重要举措,该文详细分析了即时协助聚合平台建设的技术难点、架构设计。提出情景感知的消息推送技术,精准推送相关信息并发起办公交互,设计了采用表单融合和分布提交的方式,减轻了工作人员的重复录入负担。实现了集"办公、沟通、服务"于一体,以"消息集中化、沟通实时化、办公一体化、应用桌面化、管理精细化"为根本目标的业务协同平台,提高了企业办公效率,提升了企业竞争力。     

以软交换为核心的NGN发展与应用

文章首先针对下一代通信网络的概念以及相关工作特征做出了必要的说明,而后结合NGN网络的结构,就其核心部分,即软交换的工作机制做出了进一步的分析。在此基础之上,文章就NGN网络在实际中的应用特征展开讨论,对于加深其应用特征认识有着一定的积极意义。     

移动网与固定网融合发展的思考

互联网技术已经进入了云计算时代,网络服务功能覆盖面越来越大,本文介绍了固定网、移动网的融合和发展的必然性,针对软交换技术和下一代网络技术特点,指出了移动和固定网融合的必然性。最后结合当前软交换技术的发展状况,分析了移动网和固定网融合的框架和今后趋势,并展望了下一代网络的发展。     

Boundary adaptation in grid generation for CFD analysis of screw compressors

This paper describes some aspects of an advanced grid generation method used, with Computational Fluid Dynamics (CFD) procedures, to model three‐dimensional flow through screw compressors. The increased accuracy of the flow predictions thus derived, enable such machines to be designed with improved performance and for lower development costs. To achieve this, a wholly original boundary adaptation procedure has been developed, in order to allow for convenient mapping of the internal grid points of a screw compressor, which is sufficiently flexible to fit any arbitrary rotor profile. The procedure includes a practical transformation method, which adapts the computationally transformed region to produce a regular boundary distribution on the mesh boundaries. It also allows for subsequent generation of an algebraic grid, which enables the three‐dimensional domain of a screw compressor to be mapped regularly even in regions where the flow patterns are complex and the geometrical aspect ratio is high. This procedure enables more efficient use of a CFD solver for the estimation of the flow parameters within both oil free and oil injected screw compressors, with either ideal fluids or real fluids, with or without change of phase. Copyright © 2005 John Wiley & Sons, Ltd.     

VXI总线专用协议测试模块的设计研究

随着大量军用综合电子信息系统在部队的应用，系统的装备维护倍受国内外军事装备保障专家的高度关注，研制和开发模块化的军用综合自动测试设备是目前军事装备测试领域的一大发展方向。同时，军用信息系统为完成设备的互连互通，大量采用各种专用传输协议和专用互联装备，协议的测试就成了军用综合测试系统必需解决的课题。因此，结合测试平台的研制，针对专用协议的测试需求，本文就专用的“TDMA”数传专用协议，介绍一种基于VXI总线的测试模块，着重就设计思想、方法、应用和关键技术及解决途径进行研究。     

一种新型水下移动自组织网路由算法

目前针对移动自组织网提出的路由协议普遍存在路由发现和路由维护效率低的问题,在研究按需距离矢量(AODV)路由算法的基础上,提出了一种水下多路径选择按需距离向量算法(MAODV)。该算法采用多节点路由切换机制,在一条链路失效后不必重新启动路由发现过程,而选用备用节点构成新的链路,继续进行数据包的传输,大大节省了信息资源和带宽。计算机统计仿真表明,该MAODV方法的性能在端到端通信的平均时间延迟和数据包接收率上均优于(AODV)。有效地解决了路由协议中路由发现和路由维护效率低的问题。     

深度领域自适应及其在跨工况故障诊断中的应用

实际生产中,机械设备的工况变化会造成监测数据的分布差异,破坏分类模型的应用基础,降低诊断准确率。为此,提出一种基于深度学习的领域自适应方法,用于跨工况情境下轴承故障诊断。该方法构建两个级联的深度网络:前者用于处理振动信号,自动挖掘故障敏感特征;后者用于将不同工况的样本特征同步映射到一个深度隐藏层(公共特征空间)中,消除工况波动引起的分布差异,生成工况不变特征,实现领域自适应。此外,该深度映射网络可通过参数优化方法自适应构建,能够实现最佳的跨域诊断性能。实验表明,与其他方法和相关研究相比,深度领域自适应在跨工况故障识别中具有更高的准确率。     

The Known and Unknown about the Environmental Safety of Nanomaterials in Commerce

The widespread nanomaterial use in commercial products has fed significant concern over environmental health and safety ramifications. Initially, little was known as to how these highly reactive particulates interacted with biological systems. Nanomaterials have introduced complexities not normally considered in traditional safety assessments of chemicals and therefore have generated uncertainty in the reliability of standard tests of safety. Advances in understanding the potential impacts of nanomaterials have occurred since their introduction, particularly for those used in the greatest quantities in commerce. The impact of characteristics such as charge, size, surface functionalization, chemical composition, and certain transformations on the potential effect of nanomaterials in the environment continue to move the field forward. However, generalizations of risk based on any one factor across nanomaterials is not possible. Estimating risk also remains difficult due to the introduction of materials that are new and more complex, minimal information on the specific molecular interactions of nanomaterials and organisms, and the need for more tools for measuring the dynamics of nanomaterial state and fate in complex matrices. Finally, exposure estimates are difficult due to difficulty of environmental monitoring which may be exacerbated by lack of information on nanomaterials in products and new uses in the marketplace.     

Development of a unifying theory for mechanical adaptation and maintenance of trabecular bone

Trabecular bone is a tissue with a complex 3D structure, consisting of struts and plates, which attains its mature morphology during growth in a process called ‘modeling’. In maturity, the tissue is renewed continuously by local bone resorption and subsequent formation in a process called ‘remodeling’. Both these metabolic activities are executed by bone-resorbing osteoclastic and bone-forming osteoblastic cells. It is known that bone mass and trabecular orientation are adapted to the external forces and that alternative loading conditions lead to adaptations of the internal tissue architecture. The question is how the characteristics of external loads are sensed in the bone, and how they are translated to structural adaptation of the tissue. The time scale of the underlying processes is on the order of months, or even years. This aspect makes bone a complex research topic. In this paper, we discuss the application of computer simulation to investigate the remarkable adaptive processes. We describe our developments of empirical models in the past 15 years, able to predict bone adaptation to external loads from a macroscopic level towards a cell-based level, in which the most important relationships of the cellular processes are captured. The latest model explains the morphological phenomena observed in trabecular bone at a microscopic level.     

Generation and adaptation of computational surface meshes from discrete anatomical data

Fast and accurate scanning devices are nowadays widely used in many engineering and biomedical fields. The resulting discrete data is usually directly converted into polygonal surface meshes, using ‘brute‐force’ algorithms, often resulting in meshes that may contain several millions of polygons. Simplification is therefore required in order to make storage, computation and display possible if not efficient. In this paper, we present a general scheme for mesh simplification and optimization that allows to control the geometric approximation as well as the element shape and size quality (required for numerical simulations). Several examples ranging from academic to complex biomedical geometries (organs) are presented to illustrate the efficiency and the utility of the proposed approach. Copyright © 2004 John Wiley & Sons, Ltd.     

基于IEC60870-5-104远动规约的PLC：信模块的'计与实现

为了实现对分布在很广地域的变电站或设备进行监视和控制的以太网规约IEC60870-5-104远动规约在工业通信领域的应用,首先深入分析了该远动规约的结构模型,设计了一种主要由ARM7内核的主控制器和以太网控制器构成的通信模块硬件平台,以及通过嵌入式实时操作系统来实现多任务调度的软件平台,并针对规约要求以及工业现场需求设计了主要任务的有限状态机模型。还通过实验对该模块的一致性、互操作性和系统性能进行了测试,结果表明,该通信模块具有系统独立、通讯稳定、互操作性强、可靠性高等特点。     

面向下一代网络业务部署的多维负载平衡算法

分析了用于解决下一代网络业务部署问题的已有负载平衡算法的不足,提出了一种启发式的多维负载平衡优化算法(MLOASD),并通过理论分析和实验检测证明了该算法的有效性.结果表明,用该算法能够获得系统负载平衡的近似最优的业务部署方案,其性能优于已有算法,具有实用性.