客户—服务器结构的光盘系统

随着微电子技术的迅速发展,计算机的应用日益广泛和多样化。多媒体技术的蓬勃开展就充分体现了计算机硬件、软件及应用的这种多姿多彩。而这种情形又向集中处理的大中型计算机提出了挑战。大中型计算机的信息处理能力多集中于主机,它的几十个以至数百个终端无多少处理能力。用户在终端上难以得到生动的图形界面,更不用说多媒体应用了。

Data Conversion Among Different Databases Under an Integrated Network Environment

Method for data conversion of heterogeneous DBMS's in the integrated network environment is introduced. The technical approach used can perform data conversion of heterogeneous databases located on different nodes of the network, such as Oracle, Sybase, Informix, MS SQL Server, SQL Anywhere and Foxpro. The conversion system adopts the Client/Server architecture and provides visual integrated interface for users.

PERFORMANOE EVALUATION OF HT-7 DATA PROOESSING SYSTEM

This paper describes the RTSS simulation-based performance evaluation method during the upgrade of the HT-7 data processing system to a distributed environment. We present the main concepts and steps of the method. Queueing modeling and steady-state operational analysis techniques are also used for analytic modeling. Both simulation and analysis studies on the HT-7 data processing system indicate that in comparison with conventional time-shared systems,a client/server system can significantly reduce the completion time of raw data display,real-time data processing and data transfer in the online system,raise the workload capacity and reduce the average waiting time of the off-line system.

A hybrid DVE architecture based on temp server

A hybrid distributed virtual environment （DVE） architecture is presented by importing a peer-to-peer （P2P） idea into the traditional client/server （C/S） architecture to improve the DVE system＇s scalability. The mathematical model of the overload of the center server was built and a series of simulation experiments were performed to validate the conclusions. When the client number increases to a certain value, the hybrid architecture can reduce server overload with some special clients （temp servers） selected with a certain heuristic strategy. With this architecture, the DVE system can support more system clients with the same server hardware than the C/S architecture can. The server overload ＂pulse＂ phenomena causing by the exiting of the temp server can be resolved by adopting a more optimized temp server selecting strategy and by reducing the child client capability of the temp server. By combining the advantages of the C/S architecture and the P2P architecture, the hybrid DVE architecture can effectively improve the scalability of the DVE system. This is validated by theoretical analysis and simulation experiments.

Privacy-Preserving Relative Location Based Services for Mobile Users

Location-aware applications have been used widely with the assistance of the latest positioning features in Smart Phone such as GPS,AGPS,etc.However,all the existing applications gather users' geographical data and transfer them into the pertinent information to give meaning and value.For this kind of solutions,the user's privacy and security issues might be raised because the geographical location has to be exposed to the service provider.A novel and practical solution is proposed in this article to provide the relative location of two mobile users based on their WiFi scanned results without any additional sensors.There is no privacy concern in this solution because end users will not collect and send any sensitive information to the server.This solution adopts a Client/Server(C/S) architecture,where the mobile user as a client reports the ambient WiFi APs and the server calculates the distances based on the WiFi AP's topological relationships.A series of technologies are explored to improve the accuracy of the estimated distance and the corresponding algorithms are proposed.We also prove the feasibility with the prototype of "Circle Your Friends" System(CYFS) on Android phone which lets the mobile user know the distance between him and his social network friends.

Development of a Portfolio Simulation System for Apparel Supply Chain

In this paper,a generic retailer-oriented portfolio simulation system linking manufacturer,retailer,and customer in apparel supply chain is presented.The purpose of the simulator is to generate a portfolio consisting of replenishment strategy and performance index under different sales forecasting errors to satisfy the retailer-defined customer service level in apparel industry.After analyzing the main parameters in the portfolio simulator,the procedure and detailed structure of the simulator are then described.With the use of data from the industry,one case study of the portfolio simulator is achieved and the process of the simulation is validated.

HitPeers:A P2P File Sharing System with Category Tree

HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with category. It is flexible enough to let users customize their own local CT. Its hierarchy helps users to find the information they desire most conveniently. To increase the robustness and retain the efficiency, HitPeers will divide the tree into disjoint parts. Every part is a subtree. Some special nodes named Onodes will take charge of the subtree and play the role of a service provider. HitPeers produce more and more Onodes to meet the service demands in the internet scale distributed environment. This paper will show the profile of the whole system.

Implement of the Production Monitoring and Control System for Coning,Drawing and Twisting's Workshop

To achieve the production information management of the coning,drawing and twisting's workshop,and promote a good and fast development of the textile enterprise,firstly,we analyze the information technology development status of the textile enterprise at home and abroad,study the weaknesses of the existing computer monitoring system,introduce the system design project,and propose a system network model based on client/server(C/S)mode.Secondly,a multi-agent production monitoring and control system is developed,and the communication of the single-port-multi-protocol and a multi-thread data collection technology are studied via the multi-thread and standard template library(STL)technologies.Thirdly,the system management functions,the structure design of the database,and the technical difficulties in the process of software design are also introduced.As proved in practice,the system satisfies the production management requirements of the workshop,and implements the network management of the production information.

DVE architecture based on message category

By importing the idea of P2P,and transmitting messages among clients directly into the client-server architecture,a new hybrid architecture was presented with the help of AOI technology and message category.Theoretical analysis of this architecture was presented in detail.A series of simulation experiments was carried out to verify its effectiveness.Results indicate that the new architecture produces less server message workload than traditional architectures,which can improve the scalability of DVE systems.

Application of Management Information System Planning in Concurrent Engineering for Wooden Furniture Industry

This research is a development in management information system （MIS） planning based on operation analysis and development according to concurrent engineering approach and reestablishment of database management. According to our case study industry, such industry currently used traditional network systems such as LAN, and ＂Bus Network＂ Network Topology. Client/Server distributed computing has a problem with database management in data redundancy, data inconsistency, and data independency. For Network Topology, Bus Network has problem with multitasking since the network are able to handle only a set of data at a time so the traffic problem will occur when multiple users request for the service. Thus, such condition is inconsistent with concurrent engineering which must be able to access the data simultaneously. As a consequence, this study develops a network system, network system of working system, using LAN and ＂Star Network＂ network topology. The file server processing distributed is an application while database is stored in host computer or file server but the data will be processed in users＇ computer. When the user needs to access the data, file server will send it to the user and the user can further analysis or manage such data in the user computer, so called ＂Hierarchical Database Model＂. Hierarchical database structure is easily developed like general organization command structure with different level of responsibility. In details, the data level in the database is divided into three levels including DBI, DB2, and DB3, so development of simultaneously systemic flow and access of various critical data is performed in parallel. Furthermore, this is consistent with access of all three data levels including： Level 1 is overall dataflow of both inside and outside the organization; Level 2 is dataflow of each division in the organization; and Level 3 is dataflow of subunit in each division in the organization. After systemize flow and access of data with concurrent engineering as mentioned, it provided optimal efficiency in the whole production system management reducing loss in the whole system of the organization

Develop and Implement of Real-time Network Monitoring Software based on C/S

This article mainly introduces the multi-layer distributed C/S architecture of system design scheme. Its working principle is the client program runs automatically after the computer starts, and establish communication with the application server. The network administrator can monitor and intelligent management of the client computer through the server program, the computer will execute the corresponding operation according to the server to send command instructions. The system realize the main module of the whole system framework, network monitoring data initialization module, network data transmission module, image coding and decoding module, the advantages of system make full use of existing LAN resources, timely delivery and manaRement information.

Multiple Welding Seam Video Transmission and Monitoring of Welding Robot in Local Area Network

A method of transmission and monitoring in local area network(LAN) for the welding seam video information of binocular vision welding robot is proposed.This paper uses MPEG-4 video CODEC functions of DivX,video for Windows(VFW) video capture technology,multi-threaded network communication idea and WinSock Socket in Visual C++ 6.0.In the end,client/server(C/S) communication model based on TCP/IP protocol has been developed.Experimental results show that the method can achieve the multiple welding seam video's real-time transmission in LAN.Moreover,the Canny operator is used to realize the edge feature extraction of the seam image which is captured by the client,so that the edge of the seam extracted is continuous and clear.

HydrIS: An Open Source GIS Decision Support System for Groundwater Management (Morocco)

A regional groundwater management system has been elaborated, integrating Relational Database Management System （RDBMS） and various web services. It consists of web geospatial application so-called HydrlS （ Hydrogeological Information System） based on Open Source components and technologies, leading to a feasible and low-cost solution. Therefore, HydrlS permits delivery of data from a number of heterogeneous sources to standards supported by the Open Geospatial Consortium （OGC）. The protocols used for exchanging data are also derived from OGC standards, i.e., WMS （Web Mapping Service）, WFS （Web Feature Service）, and WCS （Web Coverage Service）. Finally, a geoportal was developed, which consists of client-applications that communicate with different Web Services （WMS, WCS, and WFS） through HTTP-requests. A prototype for web-based GIS application was designed using the deegree Framework to provide systematic interfaces and functions. This system was developed to demonstrate the value of making hydrogeological data more widely accessible through client/server architecture. This experience and knowledge already gained in this project will be a source for technology transfer and policy decisions. Otherwise, this will enable user groups to improve the management of their groundwater resources and contribute to enhanced decision support capabilities.