• Proceedings of the Korea Database Society Conference
• /
• 1994.09a
• /
• pp.49-69
• /
• 1994

A client/server system has become the computing architecture for the business organization which seeks competitive edges. Technically, a client/server system places application processing close to the user and thus increases performance. This paper's two primary goals are (i) to present a performance model for client/server database systems and (ii) to demonstrate analytically the effectiveness of client/server computing in comparison with other computing architectures via an illustrative example. The model is most likely to be used as a practical performance guide for client/server computing.

• The KIPS Transactions:PartA
• /
• v.11A no.3
• /
• pp.207-212
• /
• 2004

This paper provides the higher user QoS(Quality of Service) by analyzing media service model between server and client in single VoD(Video on Demand) environment and applying it to parallel VoD environment. Media service model is divided into the Client Pull, Server Push, and IPP(Interleaving Pull & Push) model. A server sends data based on client's request in the Client Pull Model. A server one-sidedly sends data without client's request in the Server Pull model. And the WP model unites above two models. For a parallel VoD environment, We built the PMSS system which provides the parallel media streaming services that one client is simultaneously served by several servers. In the single and parallel VoD environment, We compare and analyze the performance of service models with respect to network delay and data size in buffer. In this experiment, we found that IPP service model keeps the least network delay and stable client buffer in the parallel VoD environment. This result shows that PMSS can provide the more quality of service.

• Journal of information and communication convergence engineering
• /
• v.6 no.3
• /
• pp.327-330
• /
• 2008

It is required that a server which communicates with various client simultaneously should have an efficient data transfer model. In Windows$^{(R)}$ environment, the server was generally developed based on IOCP model. Developing the IOCP model, the server generally has one data transfer buffer per client. If the server divides a larger data than the transfer buffer into several fragments, there used to be a problem in sending it to a client, because there is a conflict in a data transfer buffer. That is, CPU requests one data-fragment transfer, then it will request the next data-fragment transfer successively before completing the previous request, owing to the property of overlapped IO model. In this paper, we proposed the transfer buffer sharing technique to solve the conflicting problem. The experimental result shows that the performance of data transfer was enhanced by 39% maximally.

• Journal of Navigation and Port Research
• /
• v.35 no.9
• /
• pp.735-740
• /
• 2011

It is necessary to develop the one stop system in order to protect our marine environment rapidly from oil spill accident. The purpose of this study is to develop real time database for oil spill prediction modeling and implement real time prediction modelling with ESI and server-client GIS based user interface. The existing oil spill prediction model cannot provide one stop information system for public and government who should protect sea from oil spill accident. The development of multi user based information system permits integrated handling of real time meteorological data from external ftp. A server-client GIS based model is integrated on the basis of real time database and ESI map to provide the result of the oil spill prediction model. End users can access through the client interface and request analysis such as oil spill prediction and GIS functions on the network as their own purpose.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.12
• /
• pp.1371-1379
• /
• 1992

In this paper, we describe the general concept of digital mobile communications system and present a client-server model for the implementation of roaming function, which is on of the most important functions in digital mobile communications system. And finally we also describe our simulation test and analysis for the presented client-server model.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2001.04a
• /
• pp.507-510
• /
• 2001

HTTP/1.1 standard reduces latencies and overhead from closing and re-establishing connections by supporting persistent connections as a default, which encourage multiple transfers of objects over one connection. HTTP/1.1, however, does not define explicitly connection-closing time but specifies a certain fixed holding time model. This model may induce wasting server's resource when server maintains conn ection with the idle-state client that requests no data for a certain time. This paper proposes the mechanism of a heuristic connection management supported by the client-side under persistent HTTP, in addition to HTTP/1.1's fixed holding time model on server-side. The client exploits the tag information within transferred HTML page so that decides connection-closing time. As a result, the mechanism allows server to use server's resource more efficiently without server's efforts.

• Journal of the Korean Institute of Telematics and Electronics T
• /
• v.36T no.2
• /
• pp.42-47
• /
• 1999

This paper suggests a model of a visual information system for factory automation. The model is composed of a visual processing system with client-server model and RPC(Remote Procedure Calling); a main server for controlling the whole factory automation process; and a processing server which processes the visual information only. To verify its efficiency, the suggested model is realized on the bill recognition system.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.5
• /
• pp.797-806
• /
• 1995

The Client-Server model is a computing technique that efficiently uses distributed resources via networks. But, generating an application using Client- Server model requires many different expertises to developers in comparison to that of using the centralized computing method. That is, and application developer must be familiar with network programming and GUI(Graphical User Interface) techniques in addition to conventional programming skills. Accordingly, the time and man power have been issued for building a Client-Server system. To alleviate these problem, the Client-Server applications development tools are needed To meet such a need, we developed a GUI based tool, called Hanuri/C, for generating Client-Server application programs. In comparison to existing Client-Server tools, Hanuri/C is reinforced Multimedia facilities, Hanuri/C is reinforced Multimedia facilities. Hanuri/C is considered as a front-end part of distributed system software. That is, Hanuri/C is a Client-Server tool similar to Forth Generation Language(4GL) supporting multimedia application on top of the Distributed Computing environment(DCE). In this paper, we present the design and implementation method of the middleware part of Hanuri/c.

• The Journal of Information Technology
• /
• v.12 no.1
• /
• pp.15-20
• /
• 2009

In this paper, we aim that it solve to problem of the database hoarding because a week connectivity of wireless networks and cutting of link, Consistency of shared data, optimizing of the log include to Mobile Continuous Query Processing System under the mobile client and server environment. and we demonstrate of the superiority for the new Mobile Continuous Query Processing System compare C-I-S(Client-Intercept -Server)model with performance. and we perform to various experiment in order to establishment of superiority compare the index architecture and method for the realtime Continuous Query Processing. in this paper.

• Journal of Intelligence and Information Systems
• /
• v.13 no.4
• /
• pp.1-16
• /
• 2007

According to the expansion of the Internet use and the utilization of e-business, there are an increasing number of studies of intelligent-based systems for the preparation of ubiquitous environment. In addition, expert systems have been developed from Stand Alone types to web-based Client-Server types, which are now used in various Internet environments. In this paper, we investigated the environment of development for web-based expert systems, we classified and analyzed them according to type, and suggested general typical models of web-based expert systems and their architectures. We classified the web-based expert systems with two perspectives. First, we classified them into the Server Oriented model and Client Oriented model based on the Load Balancing aspect between client and server. Second, based on the degree of knowledge and inference-sharing, we classified them into the No Sharing model, Server Sharing model, Client Sharing model and Client-Server Sharing model. By combining them we derived eight types of web-based expert systems. We also analyzed the location problems of Knowledge Bases, Fact Bases, and Inference Engines on the Internet, and analyzed the pros & cons, the technologies, the considerations, and the service types for each model. With the framework proposed from this study, we can develop more efficient expert systems in future environments.