支持下一代无线宽带应用自适应QoS模型的研究

作为真正完整的下一代网络 ( NGN,Next Generation Network)解决方案 ,NGN需要在固定通信领域和移动通信领域都能够支持综合多媒体特性。NGN中的新一代移动通信网承载在开放式、层次化结构的分组交换网络之上 ,能够为用户提供端到端的 Qo S解决方案。本文分析了下一代移动通信系统中多媒体宽带应用的 Qo S问题 ,从无线通信系统的多层次结构出发 ,建立了业务流的 Qo S指标评判体系 ,为下一代网络中的无线宽带应用提供了一种自适应Qo S控制模型     

开发有线电视收费管理系统需注意的问题

分析有线电视业务及用户管理中出现的问题与解决办法，为系统的开发建立数据模型，以确保有线电视网络公司和用户的利益。     

铁通资源管理系统的设计和实现

在分析铁路通信资源结构的基础上,利用地理信息系统技术、数据库技术和客户/服务器(C/S)模式,为铁通(ChinaTietong)各级分公司和运营部门提供一套较为完善的资源管理信息系统。文中分析了铁通资源的结构与资源之间的关联,介绍了系统功能、物理结构及体系结构,详细分析了数据库设计、地理信息系统和系统安全性所采用的关键技术。这套系统的应用对铁通网络管理的现代化将起到重要的推动作用。     

Chemical compositions and optical properties of HfOxNy thin films at different substrate temperatures

High-k HfO_xN_y thin films have been grown by radio frequency (rf) reactive sputtering of metal Hf target in N₂/Ar/O₂ ambient at different substrate temperatures. The chemical compositions of the films have been investigated as a function of substrate temperature by X-ray photoelectron spectroscopy (XPS). XPS measurements showed that nitrogen concentration increases with an increase in substrate temperature. Room-temperature spectroscopic ellipsometry (SE) with photon energy 0.75–6.5 eV was used to investigate the optical properties of the films. SE results demonstrated that refractive index n increases with an increase in substrate temperature. Based on TL parameters which were obtained from the best fit results used in a simulation of the measured spectra, meanwhile, we conclude that the energy band gap (E_g) decreases with an increase in substrate temperature.     

有限元数值试井解释技术在复杂断块油气藏评价中的应用

有限元数值模拟试井技术,可通过描述不同网格的瞬变压力对测试范围内各个小单元进行精细描述.综合运用解析试井、数值试井联带分析方法,将测试动态成果与地质静态成果有机结合、相互补充,可实现对复杂断块油气藏的精细描述,达到一口井搞清一个小型复杂断块油气藏的目的.     

基于Web平台的机器翻译系统

用户可以通过Internet访问和使用机器翻译系统，在线机器翻译系统可以帮助用户阅读网上外文材料。用户一般通过购买相关软件或访问提供在线翻译的网站来获取翻译服务，但是专用软件价格昂贵，或者获得的在线翻译效果不能令人满意。通过Web服务与J2EE技术的结合，提出了将机器翻译拳统包装为Web服务的机制，使企业和个人能够以较低的代价方便地享受更高质量的翻译服务。     

PVR机顶盒文件存储系统的设计与实现

简要介绍了具有PVR功能的机顶盒，具体描述了PVR存储系统硬件与软件的设计与实现，重点讨论了PVR的关键部分——文件存储系统的设计和实现。     

NUMERICAL ANALYSIS OF THE EFFECTS OF LOCAL HYDRODYNAMICS ON MASS TRANSFER IN HETEROGENEOUS POROUS MEDIA

Many engineering problems require the estimation of mass transfer coefficients in porous materials. In heterogeneous materials or in cases where mass transfer sites are not spatially uniform, empirical equations for mass transfer coefficients vary widely, and the origin of these differences is not well understood. In this article, we use a stochastic algorithm to model mass transfer from single particles in a two-dimensional heterogeneous packed bed. The computed mass transfer coefficients are used to generate a distribution of local Peclet numbers in the bed. Detailed hydrodynamics are then used to interpret variations in the local Peclet number. The results show clear relationships between pore structure, streamline patterns, and mass transfer rates.     

Engineering Computation and Analysis of Enhancing Efficiency for Folded Waveguide TWT in MMW

Large signal operating equations in TWT have been solved by numerical solve method. The relations between interaction efficiency and design parameters in TWT are analyzed. A fast engineering design method of enhancing efficiency for folded waveguide TWT by velocity resynchronization is described. The computation is shown that the efficiency of Ka-band folded waveguide TWT with double taper can be enhanced over twice as original tube. This method of approach is very useful for tube designer.