• Journal of Korea Multimedia Society
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• v.9 no.11
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• pp.1503-1514
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• 2006

Today, consumers can access Internet from everywhere, therefore most commercial and other organizations provide their services on the Web. As the result, countless Web service systems are already on the Internet and more systems are under construction. Therefore, many researches of verifying that the system to be constructed will not have any deadlock and will run successfully without any problem at the early stage of design have been performed. Several Petri net based verification methods have also been published. However, they have focused on building Petri net models of Web service systems and none of them introduces efficient analysis methods. As a mathematical technique with which we can find the minimum duration time needed to fire all the transitions at least once and coming back to the initial marking in a timed net, the minimum cycle time method has been widely used in computer system analysis. A timed net is a modified version of a Petri net where a transition is associated with a delay time. A delay time used in a timed net is a constant even though the duration time associated with an event in the real world is a stochastic number in general. Therefore, this paper proposes 'Mixedly Distributed Stochastic Timed Net' where a transition can be associated with a stochastic number and introduce a minimum cycle time analysis method for 'Mixedly Distributed Stochastic Timed Net'. We also introduce a method of analysing a Web service system's response time with the minimum cycle time analysis method for 'Mixedly Distributed Stochastic Timed Net.'.

• Journal of Korea Multimedia Society
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• v.9 no.5
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• pp.671-680
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• 2006

As a mathematical technique with which we can find the minimum duration time needed to fire all the transitions at least once and coming back to the initial marking in a timed net, the minimum cycle time method has been widely used in computer system analysis. A timed net is a modified version of a Petri net where a transition is associated with a delay time. A delay time used in a timed net is a constant even though the duration time associated with an event in the world is a stochastic number in general. In the consequence, the result of minimum cycle time analysis is not realistic. Therefore, we propose ‘Stochastic Timed Net' where a transition can be associated with a stochastic number and introduce a minimum cycle time analysis method for ‘Stochastic Timed Net’ As an example of the application of ‘Stochastic Timed Net’, we introduce a ‘Stochastic Timed Net' model of a Location Based Service Providing Multimedia System and the result of minimum cycle time analysis of it. Whereas the typical form of the result of the existing minimum cycle time analysis is 'It takes at least 10 time units', the typical form of the result of minimum cycle time analysis of a ‘Stochastic Timed Net' is in the probability form such as "The probability of the events in which it finishes its job within 10 time units is 85%."

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5512-5517
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• 2012

In this paper we suggest multimedia synchronization model that is based on the Petri-net and services desirable quality of service requirement. Proposed model applies variable buffer which can be allowed, and then it presents high quality of service and real time characteristics. This paper decreases the data loss resulted from variation of delay time and from loss time of media-data by means of applying delay jitter in order to deal with synchronization interval adjustment. Plus, the mechanism adaptively manages the waiting time of smoothing buffer, which leads to minimize the gap from the variation of delay time. The proposed paper is suitable to the system which requires the guarantee of high quality of service and mechanism improves quality of services such as decrease of loss rate, increase of playout rate.

• Journal of Korea Multimedia Society
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• v.17 no.11
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• pp.1296-1306
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• 2014

Recently there are many attempts that IT convergence has been studied together with very different sector like art and music. If it is possible to make a formal model with combination of engineering with strong creative sector like music, there will be some advantages to analyze its contents easily. In this study, the model has been provided to utilize music analysis and compose algorithm through the formal model research of Sonata. To this end, this study has been provided a formal model of Sonata with the Petri net model being widely used and verify the effectiveness of the proposed model on the case of Piano Sonata K. 332.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.10a
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• pp.377-382
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• 1998

멀티미디어 시나리오를 표현할 수 있는 페트리넷을 제안하고, 멀티미디어 시나리오 작성기 제작에 이 페트리넷을 이용하는 방법을 제안한다. 또한 제안된 페트리넷을 포현된 멀티미디어 시나리오를 재생하여 주는 시스템 구현을 소개한다. 구현된 재생기는 처음부터 끝까지 차례로 출력하는 것 뿐만 아니라 '정지', '역방향 재생', '빠른 재생' 등의 기능도 갖고 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.664-666
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• 2000

기존에는 웹 환경에서 정보를 전달하기 위해 고정된 미디어들 위주로 표현하였지만, 최근 웹이 상업화, 대중화, 멀티미디어화 됨에 따라 정보를 효과적으로 전달하기 위해서는 정보를 미디어들이 결합된 연속적인 멀티미디어로 표현되어야 한다. 이러한 미디어들간의 통합 작업에서 요구되는 것이 미디어들 간의 동기화이다. 본 논문에서는 웹 환경에서 연속적인 멀티미디어를 작성하고, 재생할 수 있는 웹 기반의 멀티미디어 시스템(Multimedia System on the Web:MSW)을 설계하고, 멀티미디어의 모델링과 미디어들 간의 동기화를 위하여 MPNW(Multimedia Petri Net on the Web)을 제안한다.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.04a
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• pp.423-431
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• 1998

이진값을 가지는 이진 시스템을 모델화하고 설계하여 구현할 수 있도록 Petri Net의 한 부류인 박스의 마크수가 최대 1인 안전(safe)한 확장된 마크흐름선도(EMFG : Extended Mark Flow Graph)를 재구성하였다. 레벨박스와 펄스박스 및 게이트박스를 하나의 박스로 통일하였으며, 보존아크를 제거하고 서로 상반되는 개념을 가지는 일반아크와 역아크만을 사용하였고, 특히 트랜지션의 출력아크로 새로이 역아크를 도입함으로써 EMFG의 표현을 명확하게 하였다. 또한 EMFG에서 자기루프를 정의하였다. 그리고 이진 시스템을 모델링한 EMFG를 실제회로로 구현하는 방법이 새로이 제시되었다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.141-143
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• 1998

본 논문은 멀티미디어 시나리오 수행시간 예측 방법을 제안한다. 제안된 방법은 멀티미디어 시나리오를 확률분포표를 갖는 페트리넷(Multimedia Petri Net with probability Distribution Table: MPNDT)으로 모델링하고, MPNDT 모델에서 시나리오의 흐름을 시뮬레이션하여 시작부터 종료에 이르기까지의 수행시간을 계산하다. 사용자는 이를 참조하여 시간 사용 계획을 세울 수 있고 , 멀티미디어 정보제공자는 이를 참조하여 사용자에게 가장 효율적인 감상 스케쥴을 작성하여 줄 수 있다.

• Annual Conference of KIPS
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• 2005.05a
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• pp.1585-1588
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• 2005

무선통신 환경에서 TCP의 효율성을 개선하기 위한 ECN 방법을 하나의 페트리 넷 모형으로 표현한 사례가 있다. 이 경우에는 모형이 너무 복잡하여 ECN 방법의 구조를 한눈으로 파악하기 어렵다는 단점이 있다. 본, 논문은 기존의 모형을 추상화하여 계층적으로 표현한 결과를 보인다. 계층적 표현은 시스템 전체 구조를 이해하기가 용이하다는 장점이 있다..

• The Journal of Society for e-Business Studies
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• v.13 no.3
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• pp.67-83
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• 2008

Web caching server is one of the important components of any web site, as it makes the access of users to web content much faster while balancing the network and server load. There are many caching approaches proposed in order to solve this problem. Classically, we know several caching algorithms like FIFO, LRU, LRU-min and etc. Most of them have their advantages and disadvantages based on specific context. The purpose of this paper is to introduce the new concept of caching objects along with their related content and test the performance of the proposed caching method using CPN Tools simulator program. It is generally known that the use of Colored Petri Nets(CPNs) for modeling the simulation of new idea is one of the popular methods of system evaluation throughout software development projects. Moreover it could be very handy in describing the overall logic of the system. The CPN Tools is one of the most robust simulator programs which supports all necessary tools and functions to build and run the simulation model for CPN. Therefore in this paper, we will use CPN Tools software in order to build a simulator for our innovative caching approach named as web caching with related content. Then we will analyze the results derived from the simulation of our model and will make corresponding conclusions.