基于H．323协议的企业级VoIP语音网关的设计和实现

讨论了基于H．323的企业级VoIP语音网关的设计原则，并根据该原则设计和实现了VoIP语音网关的基本模块。文章还简要介绍了H．323协议，同时对VoIP语音网关和VoIP技术作了小结。     

VoIP网关软硬件体系结构设计

本文详细分析了一个VoIP网关的软硬件体系结构.该网关以摩托罗拉的MPC860MH为核心处理器、AudioCodec公司的AC4830xA-C作为语音处理芯片,运行VxWorks操作系统.网关同时支持H.323和SIP协议.     

基于H.323协议的VoIP语音流量识别

通过分析H.323协议和H.323协议的会话流程,基于H.323协议的VoIP通信过程中出现的会话特征,提取出通信双方的元组信息来识别整个会话流量,设计出相应的流存储、搜索、更新方案和识别VoIP流量的算法。实验表明,该方法能够准确识别基于H.323协议的VoIP语音流量。     

基于H.323的VoIP监测系统的研究与设计

H.323协议簇作为支持VOIP的主要协议之一,在VoIP领域得到广泛的应用。该文在对H.323协议过程进行系统研究的基础上,提出了一个基于H.323的VoIP监测系统的设计方案。系统主要对VoIP呼叫过程中的H.323信令进行截获、分析,获得呼叫的连接信息及通话内容的语音信息。     

VoIP双模网关的研究与系统设计

VoIP双模网关是一种同时连接VoIP网络和PSTN网络并能在两者之间互相切换的用户端网关设备,可广泛应用于小区和企业。详细阐述了双模网关的功能和工作原理,提出了一种基于H.323的支持四路话音的网关系统设计方案,包括硬件设计和软件设计方案,其中为了减少设备的物理端口数量,系统使用三相转接头。     

通信用SIP、H.323协议转换网关的初步设计

随着通信设备制造商和标准化组织,以及电信运营商的纷纷加入,VoIP系统得到了广泛的应用。VoIP技术的发展有两大方向:国际电联的H.323协议栈、IETF的SIP协议栈。本文详细介绍VoIP系统及其相关协议栈以及所用VoIP系统的具体情况,对H.323和SIP协议分别做了介绍和对比:重点讨论了基于H.323和SIP协议之间的互通问题,及硬件系统的结构设计。主要内容分析内容:不同网络之间的寻址与定位;消息的映射预处理;终端地址的转换;硬件模块的组成。具体设计了网关会话层软件程序的结构和功能模块的划分,给出了实现互通时的外部通信流程与内部消息流程,及硬件模块化设计。     

下一代网络中SIP和H.323互通网关研究和设计

随着网络技术的飞速发展,网络融合成为当前网络发展的主流趋势,信令网的融合互通显得非常重要。H.323和SIP是当前、VoIP网络上的主要控制信令,对于基于这两种协议网络互通的研究很有必要。本文分析了H.323网络和SIP网络在互通过程中所需解决的问题,实现了一个简单的H.323网络和SIP网络互通的信令网关,初步展现了软交换平台的雏形。     

基于IP的智能网络

作为科学应用国际公司的一个组成部分,Bellcore公司准备在9月份介绍一种载波类型的IP语音网关系统,对Sprint公司正在从事的工作具有着重大的影响。设计这一IP语音策略的工作关键在于通过IP语音连接实现IN(Intelligent Network)的通用特性。而和PSTN之间的接口通过H.323标准IP语音网关和Gatekeeper服务器。在今天的网     

基于H.323的VoIP监听模型的设计与实现

随着VoIP的广泛应用,如何对其实施快捷、有效的合法监听已成为当前研究的热点。对H.323协议网络及其协议自身的特点进行了研究和分析,并对基于H.323的VoIP流量的识别方法、动态会话的提取算法和网络监听流程作了重点阐述,在此基础上,提出了一个基于H.323的VoIP监听模型的设计方案。     

基于嵌入式处理器的VoIP双模语音网关设计

讨论了一种基于IP2022解决方案的双模语音网关设计.可以实现同时连接VoIP网络和PSTN网络并能在两者之间互相转换,还可在VoIP网络不可用时使用PSTN网络保障电话线路畅通,该设计使得VoIP网络的通话成本大大降低,具备很好的实用性和灵活性.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。