• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.04a
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• pp.409-414
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• 1994

A FMS is a typical discrete event system exhibiting concurrency, asynchronicity and non-determinism. Torepresent a FMS with those chatcteristics, Colored and Timed Petri Nets is defined and the modeling procedure is provided in this paper. Toanalyze and evaluate the performance of a FMS, a simulation software is developed and applied to SNU FMS/CIM Center. This software enables to detect the bottleneck machine and decide the optimaldirection in case of the expansion of a FMS.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.344-350
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• 2001

In this paper, we are focused on the analysis of acyclic schedule for the determination of the opti-mal cycle time and minimization of work in process. Especially, this paper deals with the product ratio-driven cyclic scheduling problem in FMS with different products and ratio using the TPN(Time Petri Nets)un-folding.

• 전기의세계
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• v.43 no.3
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• pp.10-17
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• 1994

패트리네트는 시스템의 관계를 시작적으로 보여주어 시스템의 모델링을 쉽게 만든다. 시스템의 각 부분에 관한 정보를 가지고 전체와 부분에 대하여 하향식(top-down)과 상향식(bottom-up) 설계를 할 수 있게 해준다. 패트리네트는 그래프 표현이므로 FMS(flexible manufacturing systems)등과 같은 실시간 제어(real-time control)의 구현에 사용될 수 있으며 토큰 정보로부터 시스템의 각 부분의 상태를 실시간 감시(monitoring)할 수 있다. 패트리네트는 PLC(programmable logic controller)와 같이 여러 요소시스템(subsystem)을 순서대로 동작시키고 조정한다. 시스테메 대한 페트리네트 모델로부터 시뮬레이션(simulation)을 할 수 있고, 이로부터 성능 평가를 할 수 있다.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.649-652
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• 2000

Beyond free choice net system this paper presents some liveness knowledge in asymmetric net system including necessary and sufficient condition for an asymmetric net system being live and having liveness monotonicity, and an algorithm, polynomial time complexity, for such deciding. Also two conjectures about system livenss are in the contribution.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.352-354
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• 2003

기존의 SOFA(Software Appliances)형의 컴포넌트에서 DCUP(Dynamic Component UPdating)통해 컴포넌트 조립이 가능하다. 이에 대해 비동기적이고 동적 시스템에 적합한 패트리 넷을 이용하여 컴포넌트의 동적 업데이 시 기존 컴포넌트와의 상호작용과 각 인터페이스에 대한 프로세스의 흐름을 정형적으로 정의하고 설계상의 모호성을 줄일 수 있도록 하였으며 보다 나은 동적 업데이트의 최적화를 위한 기반을 제공한다.

• Journal of the Korea Society for Simulation
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• v.11 no.4
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• pp.57-68
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• 2002

The analysis of the cyclic scheduling problem in FMS using the transitive matrix has been proposed. Since the transitive matrix may explain all the relations between the places and transitions, we propose an algorithm to get good solution after slicing off some subnets from the original net based on machines operations. For analyzing the schedule problem, we considered two time functions such as produce time and waiting time using the P-invariant. In addition, we are shown the effectiveness of proposed algorithm after comparing with unfolding algorithms.

• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1639-1642
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• 2013

아코디온은 키보드와 건반 그리고 공기주머니로 구성 되어 있는 악기로써 건반 악기의 특성과 화음을 위한 키보드 코드의 손가락 운영 기법이 요구되는 악기의 특성을 갖는다. 따라서, 연주를 자습하거나 독자적인 교습을 위한 연주법에 대한 알고리즘이 요구된다. 본 연구에서는 아코디온의 효율적인 연주를 위하여 손가락 연주의 알고리즘을 패트리 넷으로 표현하여 화음과 멜로디의 관계성을 표현하였다. 또한 사례를 들어 모델링을 검증하였다.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.479-485
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• 2013

Virtualization is a promising approach to consolidating multiple online services onto a smaller number of computing resources. A virtualized server environment allows computing resources to be shared among multiple performance isolated platforms called virtual machines. Through server virtualization software, applications servers are encapsulated into VMs, and deployed with APIs on top generalized pools of CPU and memory resources. Networking and security have been moved to a software abstraction layer that transformed computing, network virtualization. And it paves the way for enterprise to rapidly deploy networking and security for any application by creating the virtual network. Stochastic reward net (SRN) is an extension of stochastic Petri nets which provides compact modeling facilities for system analysis. In this paper, we develop SRN model of network virtualization based on virtual switch. Measures of interest such as switching delay and throughput are considered. These measures are expressed in terms of the expected values of reward rate functions for SRNs. Numerical results are obtained according to the virtual switch capacity and number of active VMs.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.12
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• pp.529-538
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• 2002

Conventional method to reduce the handoff call blocking probability(PBH) in mobile communication system is to reserve a predetermined number of channels only for handoff calls. To determine the number of reserved channels, an optimization problem, which is generally computationally heavily involved, must be solved. In this Paper, we propose a call admission control (CAC) scheme that can be used to reduce the PBH without reserving channels in advance. For this, we define a new measure, gain, which depends on the state of the system upon the arrival of a new call. The proposed CAC decision rule relies on the gain computed when a new call arrives. SRN, an extended stochastic Petri nets, provides compact modeling facilities for system analysis can be calculated performance index by appropriate reward to the model. In this Paper, we develop SRN models which can perform the CAC with gain. The SRN models are 2 level hierarchical models. The upper layer models are the structure state model representing the CAC and channel allocation methods considering QoS with multimedia traffic The lower layer model Is to compute the gain under the state of the upper layer models.