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

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.645-648
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• 2007

This paper describes database server management system by mobile device. Our system can control database server immediately in any where by mobile device. We have developed the dataset server CE which interface with mobile device, database management system which rons in mobile device and web services which connect the mobile database with desktop database. External mobile device communicate with web service agent via wireless equipment. Our system includes dataset server CE client engine, web service server agent and mobile device management system. Through the test by an application program, we have confirmed that our system operates very well each others.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.59-64
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• 2003

This study was carried out to develop database system using internet fur greenhouse. The database system consisted of group monitor, client monitor. server monitor and DBMS. The results of the study are summarized as follows. 1. The monitoring module, as data collection system for database. could monitor the state of the control device and the greenhouse environment. 2 The group monitor was connected to the house monitors by RS-485 communication method. Data received by the group monitor were sent to the server monitor and then stored in database server by TCP/IP and MIDAS. 3. The data of database consisted of on growing environment. control devices, operation and cultivation data in greenhouse. It was developed using MS-SQL server. 4. Remote monitoring of greenhouse was realized in a client/server environment. The client module. which was named as the client monitor. made requests to access the measurement data of greenhouse through the remote data module of the server monitor in internet environment.

• Journal of the Semiconductor & Display Technology
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• v.3 no.4
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• pp.13-17
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• 2004

As the usage of wireless LAN becomes common in working environment, the number of database systems that support both wired and wireless users increases rapidly. The characteristics of wireless LAN that its speed is slow relatively comparing to wired network and the users in its environment connects to different communication points as they moves creates another challenge to be resolved in database systems. In the environment of hybrid communication systems, wired and wireless for voluminous data amount and a number of users, the two layer architecture of the conventional client-server database systems has limitation in the system performance. This is due to that server is the only point of data service in client-server database systems. In this paper, we discuss a new extended database system architecture that data services are distributed among servers and clients based on user database access patterns in order to improve system performance. We analyze the expected system performance by using simulation technique and prove the practical utilization of the system by demonstrating experimental results.

• Proceedings of the Korea Database Society Conference
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• 1994.09a
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• pp.105-129
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• 1994

The information system of corporations are facing a new environment expressed by miniaturization, decentralization and Open System. It is therefore of utmost importance for corporations to adapt flexibly th such new environment by providing for corresponding changes to their existing information systems. The objectives of this study are to identify this new environment faced by today′s information system and develop effective methods for data resource management under this new environment. In this study, it is assumed that the new environment faced by information systems can be specified as Distributed Computing Environment, and in order to achieve such system, presents Client/server architecture as its representative computing structure, This study defines Client/server architecture as a computing architecture which specialize the fuctionality of the client system and the server system in order to have an application distribute and perform cooperative processing at the best platform. Furthermore, from among the five structures utilized in Client/server architecture for distribution and cooperative processing of application between server and client this study presents two different data management methods under the Client/server environment; one is "Remote Data Management Method" which uses file server or database server and. the other is "Distributed Data Management Method" using distributed database management system. The result of this study leads to the conclusion that in the client/server environment although distributed application is assumed, the data could become centralized (in the case of file server or database server) or decentralized (in the case of distributed database system) and the data management method through a distributed database system where complete responsibility and powers with respect to control of data used by the user are given not only is it more adaptable to modern flexible corporate environment, but in terms of system operation, it presents a more efficient data management alternative compared to existing data management methods in terms of cutting costs.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.237-244
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• 2006

The purpose of this study is to propose the online game server architecture which can expand as the number of users increases. In most online game servers, there is a server group composed of a login server, a cache server, a database server, a game server, and an NPC server, and when the number of users increases, an additional server group with the same structure is installed. The server architecture proposed in this study does not install a server group composed of a login server, a cache server, a database server, a game server, an NPC server, etc., but installs a game server only. When there is a need for the cache server and database server, the required servers will be additionally installed, thus reducing costs.

• The Journal of Information Systems
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• v.4
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• pp.85-104
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• 1995

In a loosely-coupled distributed database server system, a server failure and/or a communication failure can be masked by a resiliency mechanism. Recognizing that a distributed transaction executes at several servers during its lifetime, we propose a resiliency mechanism which allows continuous transaction processing in distributed database server systems in the presence of a server failure. The resiliency mechanism for transaction processing is achieved by keeping redundant information using a primary/backup approach. The purpose of this paper is to analyze the performance improvement opportunities with the resiliency mechanism and to present the design of the proposed system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.4
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• pp.859-868
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• 2018

Previous research related to recovering deleted data in database has been mainly based on transaction logs or detecting and recovering data using original source files by physical collection method. However there was a limit to apply if the transaction log does not exist in the server or it is not possible to collect the original source file because a database server owner does not permit stopping the database server because of their business loss or infringement at the scene. Therefore it is necessary to examine various collection methods and check the recoverability of the deleted data in order to handling the constraints of evidence collection situation. In this paper we have checked an experiment that the recoverability of deleted data in the original database source according to logical and physical collection methods on digital forensic investigation of Microsoft SQL Server database.

• Publications of The Korean Astronomical Society
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• v.21 no.1
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• pp.1-9
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• 2006

An archiving system designed to enable documenting database of astronomical images, with functions of search and download, is being developed by Korean Astronomical Data Center(KADC) of Korea Astronomy and Space Science Institute(KASI). The system consists of three PCs for web server, database server, and system management server. The search program for the web environment is operated in the web server. In the management server, several utility program we developed are installed: input program for the database, program for transfer from fits to jpg files, program for data recovery and management, and programs for statistics and connect management. The collected data would be sorted out by the system manager to input into the database. The online input is possible in an observatory where the data is produced. We applied the content management system(CMS) module for the database management. On the basic of CMS module, we set up a management system for the whole life cycle of metadata from creation and collection to storage and deletion of the data. For the search function, we employed a technique to extract indices from the metadata. In addition, MySQL is adopted for DBMS. We currently display about 2,700 and 25,000 photographs for astronomical phenomena and astronomical objects on the data, respectively.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.458-463
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• 2008

An IFC Server is a database management system that stores data complying with a standard data format, called IFC, and keeps track of data transactions, modifications, and deletions. It plays a role as an information hub for storing and sharing information between various parties involved in construction projects. There have been several efforts to develop an IFC Server, however, they suffered from slow performance and long transaction time due to a complex mapping process between IFC files and relational database structures. In this study, we aim to develop an IFC Server using an object-relational database system. Since IFC has an object-flavored data structure, we expect to have a simpler and faster mapping process from IFC to the IFC Server. This paper reviews existing studies and describes the overall framework of the OR-IFC Server.