• The Journal of Information Technology
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• v.9 no.4
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• pp.35-47
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• 2006

Many researches are going on with regard to issues and problems related to mobile database systems, which are caused by the weak connectivity of wireless networks, the mobility and the portability of mobile clients. Mobile computing satisfies user's demands for convenience and performance to use information at any time and in any place, but it has many problems to be solved in the aspect of data management. The purpose of our study is to Implement Real-Time Mobile Query Processing System(MQPS) to solve problems related to database hoarding, the maintenance of shared dataconsistency and the optimization of logging, which are caused by the weak connectivity and disconnection of wireless networks inherent in mobile database systems under mobile client server environments. In addition, we proved the superiority of the proposed MQPS by comparing its performance to the C I S(Client-Intercept-Srever) model.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.58-61
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• 2003

This paper proposes e-Learning environments far digital circuit experiment. The e-Learning environments are implemented as a WBT system that includes the circuits monitoring system and the students management system. In the WBT client-server system, the instructor represents the server and students represent clients. The client computers are equipped with a digital circuit training board and connected to the server on the World Wide Web. The training board consists of a Programmable Logic Device (PLD) and measuring instruments. The instructor can reconfigure the PLD with various circuit designs from the server so that students can investigate signals from the training board. The instructor can monitor the progress of the students using Joint Test Action Grouo(JTAG) technology. We implement the WBT system and a courseware fo digital circuits and evaluation the environments.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.2
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• pp.79-83
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• 2009

Streaming Technology can support the real-time playback without downloading and storing multimedia data in local HDD. So, client browser or plug-in can represent multimedia data before the end of file transmission using streaming technology. Recently, the demand for efficient real-time playback and transmission of large amounts of multimedia data is growing rapidly. But most users' connections over network are not fast and stable enough to download large chunks of multimedia data. In this paper, we propose an intelligent IP streaming system based on personalized media service. The proposed IP streaming system enables users to get an intelligent recommendation of multimedia contents based on the user preference information stored on the streaming server or the home media server. The supposed intelligent IP streaming system consists of Server Metadata Agent, Pumping Server, Contents Storage Server, Client Metadata Agent and Streaming Player. And in order to implement the personalized media service, the user information, user preference information and client device information are managed under database concept. Moreover, users are assured of seamless access of streamed content event if they switch to another client device by implementing streaming system based on user identification and device information. We evaluate our approach with manufacturing home server system and simulation results.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.509-520
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• 2009

The advancement of network & application technology causes a major change for the use of IT(Information Technology) equipment, including computer and mobile system. In the process from beginning with main frame in the 1960s and 70's, through the server-client paradigm in the 1980s and toward the development of network computer since 90's, computer systems are now evolutioning from isolated physical system to complementary network based virtual system[1][2]. In network based computer system, application and data required for operation are stored at not client as local system, but at server[1]. User can use application & data on a server as if those are on a local client, and a client is now toward a developing thin and network friendly system. In this paper, we discuss possible ways for the efficient implementation of thin-client. For the use of remote application & data as if in local environment, we make use of X protocol. Unlike formal simple Client - Server paradigm, we design a Proxy for middle-tier server for the improvement of QoS and session persistence. X server, Xvfb(X virtual frame buffer) are implemented on thin client and Server, respectively and we applied XSMP(X Session Management Protocol) to our framework for session management. In the end, beyond simple transfer of server display, we suggest thin client framework for the transfter of remote server application over internet.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.375-378
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• 2002

In this paper we propose parallel GA to optimize mutation rate and crossover rate using server-client model. The performance of GA depend on the good choice of crossover and mutation rates. Although many researcher has been study about the good choice, it is still unsolved problem. proposed GA optimize crossover and mutation rates trough evolving subpopulation. In virtue of the server-client model, these parameters can be evolved rapidly with relatively low-grade

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.4
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• pp.479-485
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• 2005

Recently, computing technology requires intelligent system structures for context-awareness in ubiquitous computing environment. An intelligent system for context-awareness is based on agents, and need sensor information to recognize users and frames to support service. Therefore, this paper proposes the structure of 3-tier context-awareness processing server/client that can connect dynamically with each sensor and service, and support various context stably The structure of a proposal system is composed of a client class that recognizes uses' context information, a server class that processes realized context information by an application processing agent, and a management server that manages these two classes. Also, in this structure users information is composed of dynamic profile to support exquisite service.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.153-161
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• 2009

In this paper, we designed and implemented realtime DID(digital information display) system based on web server that displayed multimedia contents. The contents are weather, news information on the internet web sites and public relations or advertisements data on local systems. The DID system has client/server architecture that the server send to client that schedule informations and multimedia contents received form web server and the client displayed the contents though scheduled information. Therefore the systems overcome network fault for the mean time. Also, the system has realtime services of web page filtering function that extract the partial information of specific web pages.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1436-1438
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• 2003

A prototype of OGC Web Map Service and Web Feature Service is developed by NEC Aerospace Systems, Ltd. under the contract from NASDA and RESTEC. The server provides satellite imagery data taken by JERS-1 and ADEOS satellite, via OGC interfaces to the client. The related features are also available to the client through the Internet with OGC interfaces. The imagery, map and feature data is handled layer by layer at the client. OGC Web Map Service and Web Feature Service interoperability capability and applicability to Digital Asia Network are demonstrated.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2391-2394
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• 2003

J2ME service technology has advantage that can embody independent and, more soft system in DICOM 3.0 and medicine reflex administration server, client′s OS that is medical treatment reflex standard in radio Internet. Also, intranet that do web based spread, and develop by system that can alternate existent client-server structure rapidly. Specialty, possibility of improvement is much because is connecting being limited in internet environment that medical equipment and information system of various kinds of machine are wire in medical institution and so on. Because do medical treatment reflex transmission module development applying DICOM technology and filtering techniques of "m-PACS" In this research, existence, by interlock in radio usable Mobile reflex conversion system design and embody. That is, patient′s information which is stored to various systems to be transmited and can give big help in medical examination and treatment to reflex client without being wooed doctor′s interpretation result and so on in place through environment to be radish tentacle bar see.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.521-530
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• 2005

Many researches are going on with regard to issues and problems related to mobile database systems, which are caused by the weak connectivity of wireless networks, the mobility and the Portability of mobile clients. Mobile computing satisfies user's demands for convenience and Performance to use information at any time and in any Place, but it has many Problems to be solved in the aspect of data management. The purpose of our study is to design Mobile Query Processing System(MQPS) to solve problems related to database hoarding, the maintenance of shared data consistency and the optimization of logging, which are caused by the weak connectivity and disconnection of wireless networks inherent in mobile database systems under mobile client-server environments. In addition, we proved the superiority of the proposed MQPS by comparing its performance to the C-I-S(Client-Intercept- Server) model.