• Korea Information Processing Society Review
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• v.2 no.2
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• pp.76-84
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• 1995

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.559-570
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• 2005

ECN is accurate in determining traffic congestion since it explicitly notifies the incipient congestion. Therefore, ECN method has been thoroughly studied in the field of wireless TCP. This paper introduces a formula to find the optimal threshold for ECN marking. We have implemented a Petri net model of 'TCP with ECN strategy' and performed simulations on it in order to verify the validity of the formula. We have also introduced ideas of applying the formula in practice. The primary contribution of this paper is proposing a formula to find the optimal threshold for ECN marking. However, introducing the Petri net model of 'TCP with ECN strategy' is no less valuable contribution because it can be helpfully used by the researchers in studying network protocols. We have built the Petri net model by modifying the existing Petri net model of TCP. In order to add ECN strategy to the existing model, we have mainly modified the network part. We have also modified sender part and receiver part as well.

• The Transactions of the Korea Information Processing Society
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• v.7 no.7
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• pp.2028-2040
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• 2000

A study on workflow as an automated business processing system is done recently. This appear proposes a method to verify commitability and integrity of workflow specifications, which include various dependencies between parallel tasks, using petri nets. For this, firstly, e describe briefly workflow specification method using workflow graphs. Secondly, we propose a method to convert a workflow graph into a petri net to verify workflow specifications. Thirdly, we suggest the commitability verification method using petri nets to check whether workflow specifications can commit or not and the integrity verification method to check whether invalid components exist or not. Lastly, we implement the proposed verification method and propose a defect extraction method.

• 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%."

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.201-203
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• 1999

음성합성에서 자연스러운 합성음을 생성하기 위하여 표준 발음법을 페트리넷 근저행렬로 모델링하는 방법으로 표준 발음법을 음가 생성 규칙으로 만들 수 있다. 본 논문은 페트리넷으로 모델링된 음가 생성 규칙의 크기를 줄이는 방법을 제안하고 구현하였다. 압축하기 전의 음가 생성 테이블의 크기는 719*107의 2차원 배열이었으며 구현된 시스템으로 압축한 결과 41*40의 2차원 구조체 배열로 압축되었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1099-1102
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• 2004

본 논문은 확장된 역할 기반 접근통제 정책에 적용된 시스템의 명세 및 분석을 위해 컬러드 페트리넷을 이용하는 방법에 관하여 기술한다.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.4
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• pp.467-471
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• 2010

Weblog is one of the most spread web services. The content of the weblog includes daily events and emotions. If we collect personal information using mobile devices and create a weblog, user can create their own weblog easily. Some researchers already developed systems that created weblog in mobile environment. In this paper, user's activity is inferred from personal information in mobile device. The inferred activities and story generation engine are used to generate text for creating a weblog. Finally, the text, photographs and user's movement in Google Map are integrated into a weblog.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.354-361
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• 2011

Increasing interest and technological advances in smart home has led to active research on context-awareness service and prediction algorithms such as Bayesian Networks, Tree-Dimensional Structures and Genetic prediction algorithms. Context-awareness service presents that providing automatic customized service regarding individual user's pattern surely helps users improve the quality of life. However, it is difficult to implement context-awareness service because the problems are that handling coincidence with context information and exceptional cases have to consider. To overcome this problem, we proposes an Intelligent Sequential Matching Algorithm(ISMA), models context-awareness service using Timed Petri-net(TPN) which is petri-net to have time factor. The example scenario illustrates the effectiveness of the Timed Petri-net model and our proposed algorithm improves average 4~6% than traditional in the accuracy and reliability of prediction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.101-106
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• 2011

In this paper, our goal is to design the controller which operates a manufacturing system, discrete event system, guaranteeing user specification. In specially, based on supervisory control theory W. M. Wonham, our work consists in performing the controller using Petri nets possible parallelism. In addition, we consider the problem of allocation for resources sharing of the issues to consider when designing using Petri net. The controller can be generated by synthesis of user specification model and plant model after giving the management for the resource sharing. This created controller can control the deadlock and starvation which can occur in the case with resource sharing. Previous studies proposed the Constrained Synchronous Reachability graph to synthesis of the two Petri nets models. Therefore, we provide the controlled system which forbids a deadlock and starvation using the result of previous studies.

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.9-17
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• 2007

This paper introduces a Petri Net-based multimedia programming method. For this purpose, we are proposing MPN(Multimedia Petri Net) which can be used for representing a multimedia scenario. We are also introducing methods to analyze a MPN with which we can detect some kinds of design faults in the scenario. A multimedia program replays the scenario by interpreting the MPN. A method to implement such a multimedia program is also discussed. Our multimedia program provides the manipulation functions of stop, play, fast forward. rewind, and fast rewind. There are many varieties of Petri Net. Several of them are for modeling multimedia scenarios. They all have been used for synchronization analysis. But none of them were used for replaying multimedia scenario. We have extended these nets to MPN. A MPN model contains not only the flow of a scenario but also all the information associated with the data units. Therefore, our player can play the multimedia scenario by interpreting the MPN.