基于多层结构中间件（EdbClient,EdbServer）的设计与实现

文中首先分析了Ｃｌｉｅｎｔ／Ｓｅｒｖｅｒｓ模型中中间件的应用背景。     

基于构件模型的系统设计研究

本文利用Web Service技术思想和构件的强装拆性思想,将可复用的、基于构件的应用系统框架同内部的业务构件实现分离开来,以提高系统框架的可复用性;设计了一个典型的系统框架,在系统框架内实现构件的管理和互操作,以使系统具有良好的可移植性、可复用性和可维护性。     

基于J2EE的分布式多层应用系统的设计和实现

构建在分布式多层结构上的应用有着层次结构清晰、可伸缩、可配置、灵活可靠性以及跨平台等优越性,因而分布式多层结构模型成为当前主要的企业应用模型。文中主要讨论多层结构计算模式的优点和现在流行的分布式计算平台的比较,并在此基础上,给出一个基于J2EE的分布式多层计算平台在呼叫中心中的应用案例。从而使人们更加充分了解分布式多层应用系统意义。     

C／S模型中中间件的一种实现方法

文章首先分析了Client／Server模型中中间件(middleware)的应用背量,阐述了中间件的概念。在此基础上,以南宁百货大楼商业自动化管理信息系统(NBMIS)的开发为例详细说明了基于多层结构(multitier)的中间件的一种实现方法。     

用Java实现B／S多层结构的网络图文档管理

针对现代企业图文档管理系统的要求,介绍基于B/S多层结构的网络图文档管理系统的Ja-va语言实现方法,系统体系结构、实现的主要功能及关键技术。     

多线程在分布式多层管理信息系统中的应用

在分布式多层管理信息系统中,信息查询往往是用得最多的操作,查询效率的高低通常能决定整个系统的优劣。利用Delphi多线程技术,探讨了一种在客户端有效的实现远程数据存取的方法。     

Joint interference coordination approach in femtocell networks for QoS performance optimization

Future heterogeneous networks with dense cell deployment may cause high intercell interference. A number of interference coordination (IC) approaches have been proposed to reduce intercell interference. For dense small‐cell deployment with high intercell interference between cells, traditional forward link IC approaches intended to improve edge user throughput for best effort traffic (ie, file transfer protocol download), may not necessarily improve quality of service performance for delay‐sensitive traffic such as voice over long‐term evolution traffic. This study proposes a dynamic, centralized joint IC approach to improve forward link performance for delay‐sensitive traffic on densely deployed enterprise‐wide long‐term evolution femtocell networks. This approach uses a 2‐level scheme: central and femtocell. At the central level, the algorithm aims to maximize network utility (the utility‐based approach) and minimize network outage (the graphic‐based approach) by partitioning the network into clusters and conducting an exhaustive search for optimized resource allocation solutions among femtocells (femto access points) within each cluster. At the femtocell level, in contrast, the algorithm uses existing static approaches, such as conventional frequency reuse (ReUse3) or soft frequency reuse (SFR) to further improve user equipment quality of service performance. This combined approach uses utility‐ and graphic‐based SFR and ReUse3 (USFR/GSFR and UReUse3/GReUse3, respectively). The cell and edge user throughput of best effort traffic and the packet loss rate of voice over long‐term evolution traffic have been characterized and compared using both the proposed and traditional IC approaches.     

A Web-Based Remote Cooperative Design for Spatial Cam Mechanisms

Proliferation of the Internet has provided a great opportunity to exploit the advantages of distributed design and manufacturing. This paper presents an approach to component-based distributed cooperative design over the Internet where an extended multi-tier model (Browser/Server) is used to implement the web-based remote design system. As a case study, the system has been used to design spatial cam mechanisms based on mathematical models. Some experimental results are reported in order to illustrate the flexibility of the approach and the capabilities of the system. ID="A2" Correspondence and offprint requests to: Dr Gui Yun Tian, School of Computing and Engineering, University of Huddersfield, Huddersfield, HD1 3DH, UK. E-mail: g.y.tian@hud.ac.uk     

Multitier heterogeneous network using stochastic geometry and factorial moment approaches

The rapid growth of small cells is driving cellular network toward randomness and heterogeneity. Usually, cellular networks are modeled by placing each tier (eg, macro, pico, and relay nodes) deterministically on a grid. In such a heterogeneous cellular network, the rational approach to characterize the base stations (BSs), user, and relay locations is by using random spatial models. When calculating the metric performances such as coverage probability, these networks are idealized without consideration of interference. Therefore, interference modeling remains the key issue for the deployment of small cells. This paper developed a single and multitier cellular network model that captures the downlink heterogeneous cellular network with variable parameters such as the target signal‐to‐interference ratio (SIR), transmitted power, and deployment density. In particular, we model ‐tier transmission and compare it with a single‐tier and traditional grid model to obtain tractable coverage probability using stochastic geometry and factorial moment. The obtained results demonstrate the effectiveness and analytical tractability to study the heterogeneous performance.     

多层体系结构在数据挖掘系统中的应用研究

数据挖掘系统是计算密集型的应用系统,性能的提高是整个系统设计的关键。文章在多层体系结构理论的基础上,提出了数据挖掘系统的多层体系结构及其J2EE实现方案,通过将应用逻辑移入中间层,减少了数据库服务器的负担,增加了系统的扩展性,增强了对多用户的控制和管理,从而提高了数据挖掘系统的性能。