• IE interfaces
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• v.17 no.2
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• pp.226-232
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• 2004

In shipbuilding area, data sharing is one of the crucial issues. Recently, for collaborative design, ship structural CAD systems adopt the database as its primary storage. Database is useful to deal with the large amount of design information among the heterogeneous design department and design stage. To make the database-based CAD system object-oriented database(OODB) and object-relational database(ORDB) can be used. It is important to select proper database because the CAD system performance mainly depends on access performance of database. In this research, using prototype CAD system from other research, access performance of OODB and ORDB form CAD system was evaluated. STEP application protocol was used as the database schema and experiment was made in query by property and query by region. The results give some idea of how to choose the database for CAD systems.

• Journal of Korea Multimedia Society
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• v.2 no.2
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• pp.145-154
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• 1999

We are very interested in electronic commerce today, and it will is more developed in the future. In electronic commerce, we can easily purchase a cheap goods like digital data using a micropayment system. Though small value is used in micropayment system, it is important because it has many application. The transaction cost of a micropayment system must be small. Many protocols for the micropayment system are studied, but it's not support user's anonymity. In this paper, we examines the existing micropayment system and proposes a new micropayment protocol that have a anonymity.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1553-1556
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• 2001

무선 이동 통신 인구의 증가와 무선 서비스에 대한 수요는 증가하고 있으며 이에 맞추어 무선휴대 장치의 성능도 빠르게 발전을 하고 있다. WAP 포럼에서 제정한 WML(Wireless Markup Language)을 사용한 무선 컨텐츠의 제작이 활발하게 이루어지고 있는 가운데 보다 더 동적인 WML 무선 컨텐츠의 요구가 증가하고 있다. 그로 인해 개발자가 실제와 같은 상황에서 WML과 WML Script 컨텐츠를 편리하게 테스팅 할 수 있는 환경이 필요하게 되었다. 따라서 본 논문에서는 CP(Content Provider)들이 작성된 WML(Wireless Markup Language) 컨텐츠(Content)를 쉽고 편리하게 브라우징하면서 테스팅 하기 위하여 필수적으로 요청되는 WAP(Wireless Application Protocol) 에뮬레이터 및 무선컨텐츠 제작에 필수적인 WMLScripts 해석기의 설계 및 구현에 대해 기술한다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.352-354
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• 2002

Explicit multicast 는 narrowcast 기술의 일종으로써 소수의 참여자가 참가하는 다수의 멀티캐스트 그룹을 지원하는데 효과적인 멀티캐스트 프로토콜이다. 기존의 멀티캐스트기술에 비해 Explicit multicast 는 세션별 정보를 유지하고 있지 않기 때문에 네트워크 대역폭을 절약할 수 있고 확장성에 대한 강점을 가지고 있다. 본 연구에서는 Explicit multicast 프로토콜의 특징들을 분석해 보고 Explicit multicast 프로토콜을 지원하는 라우터를 Linux 기반 플랫폼에서 동작하도록 구현하여 Explicit multicast 실험 네트워크를 구축한다. 또한 Explicit multicast 프로토콜 응용프로그램을 개발하여 구축된 Explicit multicast 네트워크와 연동시켜 프로토콜의 동작을 확인한다. 이러한 개발 및 실험 결과를 바탕으로 향후 Explicit multicast 프로토콜이 효과적으로 사용되기 위한 개선점들을 제안한다.

• Journal of the Korean Professional Engineers Association
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• v.29 no.3
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• pp.94-104
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• 1996

When Broadband Integrated Services Digital Network(BISDN) becomes commercially available In public network, conventional Local Area Network(LAN)s will still be in use. The first wide spread application for B-ISDN will be the interconnection of LANs. The equipment providing the connection between the LAN and the BISDN will be given the general name Inter Working Unit(IWU). We addresses the congestion problem of many interworking issues. In this paper, Our study is concentrated on applying connectionless network protocol for interworking. We suggest a rate control method in the network layer to prevent a buffer overflow in the IWU. Since this rate control method can be applied to prevent buffer overflow in a congested IWU, We investigate the use of rate control to solve congestion problems of IWU and parallize network layer with rate control to lessen the congestion problem in IWU.

• Journal of Korean Physical Therapy Science
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• v.16 no.3
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• pp.67-74
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• 2009

Background: Various functional factors should be incorporated during assessment and intervention for patient rehabilitation. Stable respiratory function is one of required factors for functional restoration. To maximize respiratory physical therapy intervention outcome, it is required to understand clinical features of respiratory diseases and physical therapy approaches. Methods: Previous studies were systematically reviewed through computerized search. Methodological qualities of selected studies were evaluated and the levels of recommendations were determined. Results: Assessment for respiratory pattern and thoracic mobility is of importance to improve cardiopulmonary fitness during physical reconditioning. Application of optimal therapeutic protocol can increase thoracic mobility and respiratory function. Interdisciplinary communication is critical during rehabilitation for respiratory patients. Health care provider should have professional knowledge and experience for cardiopulmonary fitness and obligation to endeavor for patients' respiratory rehabilitation. It is necessary to standardize therapeutic intervention, and rehabilitative respiratory exercise should be applied to confirm the effects of intervention. Conclusion: Respiratory diseases that may reduce patients' quality of life and cardiopulmonary fitness should be resolved through physical therapy approaches. Through conducting research, effect of evidence-based and patients' function-oriented intervention can be determined.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.799-801
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• 2005

There have been many streaming servers that provide a large number of contents for a user's preference. General purpose streaming sewer makes use of a RTSP protocol for streaming controls such as message passing with client players. To date, there has been minimal research regarding streaming server's performance test tools. For measuring streaming server's performance, performance evaluation technique is needed and also achieved by RTSP based controls, a server's performance result and its miscellaneous test tools such the PseudoPlayer for pumping data to a specified port and the PseudoMonitor for gathering information. In this paper, We implement a test toolkit for evaluating a streaming server's performance and show the case of its application

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.229-231
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• 2001

IPSec is a security protocol suite that provides encryption and authentication services for IP messages at the network layer of the Internet. Key recovery has been the subject of a lot of discussion, of much controversy and of extensive research. Key recovery, however, might be needed at a corporate level, as a from of key management. The basic observation of the present paper is that cryptographic solutions that have been proposed so far completely ignore the communication context. Static systems are put forward fur key recovery at network layer and solutions that require connections with a server are proposed at application layer. We propose example to provide key recovery capability by adding key recovery information to an IP datagram. It is possible to take advantage of the communication environment in order to design key recovery protocols that are better suited and more efficient.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.50-58
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• 2007

We design a filtering management scheme with synchronization function under a realtime RFID middleware system for larger-scale data processing. The application interface(AI) is to support a various access protocol, HTTP, XML, JMS, and SOAP for the RFID applications. Generally, the synchronization problem is occurred in multiple accessing of clients for single filtering file. In this paper, we implement a filtering management scheme supporting the synchronization using the filter management process, and then demonstrate the RFID middleware filtering scheme.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.707-710
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• 2007

The sensor network by using Utrasonic transceiver is concerned about the dampness of the signals caused by distance among the nodes, the distortion for speed of data trasmission and the transport protocol. The motes are sized $50mm\times60mm$, the ultrasonic analog part sized $30mm\times40mm$ and record 2% error rate for data transport.