• Proceedings of the KSME Conference
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• 2000.04a
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• pp.884-889
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• 2000

This paper describes the design and implementation of PCOAMC(PC-based Open Architecture Machine Controller) to be flexible and independent from the vendor-oriented hardware and software structure. This openness approach is able to enhance an intelligence and integration of a manufacturing system. The development methodology of PcOAMC is an Object-Oriented approach, and all modules in PcOAMC are modelled using UML(Unified Modelling Language) that provides an easy understanding and modification. In order to demonstrate an applicability of PcOAMC, a simple test has been executed by using the Client-Server system consisting of two PcOAMCS and bus monitoring system. The good results have been obtained, so that the developed controller is expected to be embedded into IMS(Intelligent Manufacturing System) as a basic unit.

• The Journal of Society for e-Business Studies
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• v.7 no.2
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• pp.83-95
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• 2002

Because XML is a W3C standard and has characteristics like platform-independent, it has a critical role in e-commerce. Business rules and procedures should be standardized for efficient B2B integration. But a lot of companies has its own XML documents instead of standard documents. Therefore many organizations try to make standards for e-commerce based on framework. In this paper, n messaging system is designed and implemented. Client request service in a XML and server return response in XML in this system. So we can more easily and efficiently build e-Procurement system based on this XML messaging system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1527-1537
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• 2006

The server system of digital contents has to how the context information about client devices to provide the appropriate contents for each device effectively. CC/PP standard specification is an agreement for describing and transmission of the information related with a client device. In this case, the information on device hardware and software, networks and user's preference is included here. In the mean time, WAP forum defined W-HTTP protocol to transmit the CC/PP profile information of a client device to a server system. However, the client devices which use existing HTTP protocol to transmit their information cannot provide the CC/PP profile information to a server. In this paper, we propose an effective method to create and provide the CC/PP profile in the clients which use not only HTTP protocol but also W-HTTP protocol to transmit device information.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1085-1092
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• 2003

The rapid growth of high speed multimedia services demands the large capacity of the server's storage that maintains the multimedia contents. Among the server's devices, the low I/O speed and physical or logical failure of storage device decrease the total performance of system. The continuous increase of multimedia contents require the flexibility of storage capacity. In order to solve the these problems, we propose the uses of software RAID and LVM techniques that provide the performance improvement and reliability of storage device and the flexibility of storage device respectively. In the LINUX 2.4 kernel, we implemented the reliable and flexible storage device and evaluated the performance of it.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.151-153
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• 1996

The purpose of this paper is the development of Integrated Bio-signal Management System(IBMS) using the network. IBMS is the system to manage the medical signals that measured from the each independent medical measurement system module. Each has a LAN. We developed the file-server network using Novell Netware. Also, we developed the Graphic User Interface software for IBMS using Visual C++ at Windows 3.1.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.2
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• pp.121-131
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• 2001

The failure of network and/or node on which server object is executed is a single point of system failure in the CORBA application. One of the possible ways to overcome such problem is to replicate server objects to several independent nodes. The replicated objects executing same tasks are called object group. In order to provide fault tolerance of server object, this paper proposes and implements new CORBA model that supports the object group based on active replication. The proposed model not only provides interoperability with existing CORBA application but also minimizes additional application interface required to support object group because it uses nop to exchange messages between client and server. And this paper extends IDL structure. Depending to application logic, it makes possible to prevent performance degradation caused by consistency maintenance. At present, this paper supports only active replication. But it can be easily extended to provide warm ancVor cold passive replication without modification of architecture required for active replication.

• The KIPS Transactions:PartD
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• v.10D no.1
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• pp.153-160
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• 2003

Recently, deployments of firewalls and NATs ire increasing to provide network security features or to solve the problem of public IP shortage. But, in these environments, peers in different firewall or NAT environments may get limited services because they cannot open direct communicate channels. This can be a significant problem in pure P2P environments where the peers should get or provide services by opening direct channels among themselves. In this paper, we propose a scheme for dynamically selecting a peer that fan be used as a proxy server. The proxy server supports the communication between the peers in different firewall or NAT environments. The proposed scheme is operating system independent and supports bidirectional communication among the peers in P2P environments. Additionally, the proposed scheme can distribute network traffic by dynamically allocating proxy servers to the peers that is not located in the firewall or NAT environments.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.2
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• pp.54-62
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• 2001

In this paper, we proposed multimedia based ExamBank system in web environments. In the proposed system the database was designed based on the object-relation model and the application program was implemented with Java such that independent execution would be possible to guarantee no fault for multi-client in Web environments. We defined the Exam entities as objects, and implemented those inter-relationships as user definition and type. In addition, by mapping the schema object of DBMS and JAVA class, it becomes to possible transferring the object systematically between DHMS and JAVA application server.

• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.699-709
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• 1999

This paper is aimed at defining items of analysis using SNMP MIB-II for the purpose of managing the Internet based network running on TCP/IP protocol, and then utilize these items, in conjunction with various Web technology and JAVA to design and implement a Web based interface of a management system to analyze the performance and status of the Internet. Among the required items in order to accomplish this task are utilization, interface packet transmission rate, I/O traffic ratio, and so on. Based on these items, the actual analysis is carried out by the Web interface according to the type of analysis. For instance, the interface executes the function of real-time analysis, collection processing, elementary analysis and detailed analysis. The demand of the user is fed into the Web interface which carried out a real-time analysis with the client system which in turn will eventually produce the results of the analysis. In order words, the interface acts as a mediator server for the analysis system. Furthermore, a protocol for exchange of data and messages between the server and the analysis system, the MATP protocol, was also designed. Finally, the results obtained through the system presented in this paper were displayed on screen according to the type of analysis. The system realized in this paper uses We technology and is independent of platform and allows the user to determine the performance of Internet at his/her own host according to the selected items of analysis.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.6
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• pp.36-46
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• 2002

This paper proposes an integrated scheduling mechanism for embedded system with real-time web server to meet the characteristics of real time task. The proposed scheduling mechanism may solve the so-called priority inversion problem in scheduling between urgent web requests and tasks with low priorities. The priority inversion problem happens because of operating two independent schedulers, web scheduler and operating system scheduler in a system without considering the requirements of each other. In the proposed mechanism, two schedulers are integrated in an operating system and the integrated scheduler schedules tasks for urgent web requests with real time characteristics and other application tasks together. Since all tasks are scheduled by one unified scheduler that knows the characteristics of tasks, the tasks are scheduled with their absolute priorities and thus the priority inversion problem can be eliminated. The performance is measured on a prototype embedded system with the proposed algorithm.