• Proceedings of the Korea Database Society Conference
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• 1995.12a
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• pp.117-126
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• 1995

본 논문에서는 분산 환경에서 멀티미디어 문서를 공동 저작하는 시스템을 설계하는 데 있어서 고려해야 할 요구 사항들을 분석하였다. 또한 이들 요구 사항을 만족시키는 문서 구조 DMDA (Distributed Multimedia Document Architecture)의 기본 개념을 소개하였다. DMDA는 논리 구조 지향적이다. 표현 객체와 상대공간 합성의 도움으로 동적인 재배치가 가능하다. 또한 사용자 관점에 따를 문서 출력이 가능하고 버전 관리가 쉬운 구조로 되어 있다. 공동 작업 중에 문서 위에 행해진 표시나 주석은 표시객체에 담겨 분산된다 분산 멀티미디어 환경에서 문서를 편집 또는 공동 저작하는 시스템은 분산 객체들을 조합하여 하나의 문서를 만들 수 있기 위하여 논리 구조 지향적이고 구조 편집 지향적이어야 한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.33-36
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• 2004

공개키기반구조(Public Key Infrastructure, PKI)는 인터넷상에서의 안전한 전자거래를 위한 보안기술의 핵심적인 요소이며, OCSP(Online Certificate Status Protocol)는 PKI에서 공개키 인증서의 상태를 검증하기 위한 프로토콜이다. 최근 단일 OCSP 서버의 업무 부담을 줄이고 OCSP 서버의 개인키 노출에 대한 영향을 최소화시킬 수 있는D-OCSP(Distributed OCSP) 시스템이 제안 되었다. 본 논문에서는 신원기반의 암호기법을 이용하여 효율적인 D-OCSP 시스템을 설계하기 위한 방안을 제안한다.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.883-892
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• 2009

SOAP using WSDL(Web Service Definition Language) was proposed for effective integration of distributed objects. But the SOAP message and WSDL document automatically generated from development tool are fully dependent on the development environments. So the dependency of SOAP messages and WSDL documents for objects to the development environment is still a big problem to be solved for the integration of heterogeneous distributed objects. In order to support integration of heterogeneous distributed object, we implemented SOAP Bridge called WBSB(WSDL Based SOAP Bridge). As service request message for a particular service object is translated into appropriate SOAP message for the selected service object by WBSB using WSDL repository, a client can use service object without considering the development environment of the service object.

• Journal of Korea Multimedia Society
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• v.12 no.2
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• pp.178-190
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• 2009

XML is recommended by W3C(World Wide Web) and widely accepted as a standard markup language for expression and sharing data. Recently, increasing the use and the amount of XML documents, there is required that easy methods for accessing XML documents at anytime and anywhere, therefore, the distributed XML repository systems is developed. For this, distributed XML repository systems is necessary to research catalog management schemes. In this paper, we design distributed XML database model considering CPU costs, I/O costs, concurrency control, two-phase commits a protocol, queuing delay and so on. And we implement a simulator in order to execute performance evaluation centralized catalog method, fully replicated catalog method, and partitioned catalog method using reasonably setting up environments.

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

• Proceedings of the ESK Conference
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• 1995.10a
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• pp.46-55
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• 1995

The multimedia documents becomes the most natural user interface for CSCW(Conputer Supported Cooperative Work) in distributed environment. The objective of this study is to propose a multimedia document architecture and to develop a system that can manage it well. The new architecture is for revisable documents and is the basic layer for hypermedia documents. A good document architecture for CSCW must support pointing, marking, and editing over a part of documents. The user views, version control, and full- content search are also desirable features. In this paper, we discuss the basic concept of a new document architecture for CSCW. We also present the user interfaces for spatio-temporal compositions of multimedia documents.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.367-377
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• 1998

In this paper, we propose a framework (named Multimedia Service Framework) that provides the development and operation of different kind of multimedia applications. This framework defines the architectures and its functionalities for supporting multimedia services, in 3 layers of: Application, Distributed Support System and Network. Firstly, we analyzed general characteristics of multimedia applications, and defined a set of horizontal and vertical services in the Application Architecture. Also, we determined functionalities and services required to support all application services in the Distributed Support System Architecture which must provide functions for the distribution transparencies, resource sharing, interoperability and portabiliy. Finally, in the Network Architecture we proposed the network infrastructure and services to increase the efficiency in resource management and processing capacity of network components such as router and switch, adopting the active networking approach.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.227-229
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• 2005

This paper proposes a method of implementation of digital convergence platform(DCP) which enable the service of broadcasting, communication, multimedia and home automation. Also digital convergence platform based on MPEG-21 multimedia framework can be a model to provide a distributed electronic commerce environment of multimedia and to manage of it. Platform hardware is implemented using a general purpose CPU and high performance digital signal processor and has peripheral units for network and multi I/O. It is able to run applications of multimedia which has variable formats on DSP. In addition, a personal transaction of multimedia packaged with MPEG-21 multimedia framework is provided on digital convergence platform. Like this, digital convergence platform bring up a new architecture of multimedia systems using a new generation network.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3785-3793
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• 2000

Effective synchronization specification model which can specify temrxlral relationship among media resolving asynchronous problem due to variable network delay is necessary in a distributed multimedia system. Therefore in this paper, we propose RTPN(Real- Time Petri Net) synchronization specification model based on Petri Net for multimedia application in a distributed real time environment. The proposed RTPN model supplies a tlexible decsription of the temporal relationship among various media objects by defining primary key media and relative key media according to delay and importance among media. Firing rule is instantly executed by firing function based on QoS values which supports intra-media and inter-media syncbronization. And asynchronous control algorithm for resynchronization of presentation level is possible more effective supporting of QoS.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.785-790
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• 2008

Our Digital Carousel enables user to share media objects through media synchronization mechanism. We implemented the Digital Carousel so that the users participated in collaborative work may refer shared media or error objects as the same view to others. In this paper, we discuss a method for increasing reliability through fault tolerance. We describe the design and implementation of the ER running on distributed multimedia environment. ER is a system which is able to recover automatically a software error based on distributed multimedia. This paper explains a performance analysis of an error recovery system running on distributed multimedia environment using the rule-based DEVS modeling and simulation techniques. In DEVS, a system has a time base, inputs, states, outputs, and functions.