• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.14 no.5
• /
• pp.511-520
• /
• 1989

Generally, Intelliget link is made of drawing picture that is amalgated in two conception of communication and processing. This is a new system of information transmission having fuction being able to handle een though the former information transmission can not be possible. That Intelligent link is to say that function of each segment by working software can be anailable at general purposed pipeline processing system, general purpose pipeline have a different working time in function of segmant, work asynchronizing pipeline. in the papers, graphic design is easy to understand the sense of sight model by Petri Net that is simple regulation. it can translate into working of asynchronzing pipeline by working of calculator of simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.189-192
• /
• 2005

In this paper, we present a Petri Net (PN) model for reliability analysis of a shared database system. The system consists of components; a database, two processors, two memory and a bus. The database should be operational and at least one of the component should be also operational. Otherwise system will be down. Each component can be failed and repaired individually. Stochastic Reward Net (SRN) Model for reliability analysis is developed. SRN is potential to define various reward function and can be easily used to obtain performance measures. The modeling techniques using variable cardinality, enabling function, timed transition priority in SRN are shown.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.39 no.6
• /
• pp.53-67
• /
• 2002

The multimedia synchronization is one of the key issues to be resolved in order to provide a good quality of multimedia related services, such as Video on Demands(VoD), Lecture on Demands(LoD), and tele-conferences. In this paper, we introduce an adaptive multimedia synchronization algorithm using the level of buffers and load of servers, which are modeled and analyzed by ExSpect, a Petri net based simulation tool. In the proposed algorithm, the audio and video buffers are divided to 5 different levels, and the pre-defined play-out speed controller tries to make the buffer level to be normal in different temporal relations between multimedia streams using buffer levels and server loads. Because each multimedia packet is played by the pre-defined play-out speed, the media data can be reproduced within the permissible limit of errors while preserving the level of buffers to be normal. The proposed algorithm is able to handle and support various communication restrictions between providers and users, and offers little jitter play-out to many users in networks with the limited transmission capability. The performance of the developed algorithm is analyzed in various network conditions using a Petri net simulation tool.

• Journal of Korean Institute of Industrial Engineers
• /
• v.25 no.1
• /
• pp.87-99
• /
• 1999

A shop floor control system(SFCS) performs the production activities required to fill orders. In order to effectively control these activities, the autonomous agent-based heterarchical shop floor control architecture is adopted where a supervisor does not exist. In this paper, we define functional perspective of the heterarchical shop floor control using planning, scheduling, and execution modules. In particular, we focus on an execution module that can coordinate the planning and scheduling modules and a general execution module that easily can be modified to execute the other equipment. The execution module can be defined informally as a module that downloads and performs a set of scheduled tasks. The execution module is also responsible for identifying and resolving various errors whether they come from hardware or software. The purpose of this research is to identify all the execution activities and solving techniques under the assumptions of the heterarchical control architecture. And we model the execution module in object-oriented modelling technique for generalization. The execution module modeled in object-oriented concept can be adopted to the other execution module easily. This paper also proposes a classification scheme for execution activities of the heterarchical control architecture. Petri-nets are used as a unified framework for modeling and controlling execution activities. For solving the nonexistence of a supervisor, a negotiation-based solution technique is utilized.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.355-358
• /
• 2007

In wireless mobile communication systems, priority of voice service through high speed data and multimedia transmission requires increased service diversification. Research is being carried out in this environment, on the call admission control techniques to guarantee the diversified service's QoS. SRN (Stochastic Reward Net) is an extended version of Petri nets, well know modeling and analysis tool. In this paper, we develop SRN call admission control model considering the 4 classes of services in the 4th generation IEE 802.16e mobile communication Technology.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.15 no.6
• /
• pp.516-525
• /
• 1990

This paper proposes a hierarchical control algorithm for an efficient network management of a loosely-coupled system which consists of functional division and duplicating structure with a LAN to enhance reliability and availability. The algorithm is modeled using the Perti-net and verified with the reachability tree. Here, the proposed algorithm is compared with the purely centralized control algorithm and distributed control algorithm in terms of message traffic for the network management. The result shows that the message traffic related to system performance is as low as centralized control algorithm and the system availability is independent of a specific processor failure.

• ETRI Journal
• /
• v.7 no.3
• /
• pp.49-58
• /
• 1985

통신망 프로토콜은 정보통신망의 중추 신경계를 형성하면서 통신망 시스팀을 구성하는 각 부분들과 전체적으로 조화있게 동작하여야 한다. 최근에 이르러 통신망의 규모 및 복잡성이 증대되고 통신망 시스팀을 구성하고 있는 부분적인 시스팀들이 여러 회사에서 생산됨에 따라, 통신망 프로토콜에 대한 규격을 보다 정확한 방식으로 기술하는 것이 필요하게 되었다. 프로토콜을 정확하게 기술하기 위하여는, 통신망 프로토콜을 정확하고 모호하지 않게 표현 할 수 있는 형식 표현 기법(FDT : Formal Description Technique)이 정의되어야 한다. 지금까지 널리 받아들여지고 있는 대표적인 FDT에는 ESTELLE(ISO 422), LOTOS(ISO 423), SDL 및 Petri Net 등이 있으며, 이들 FDT에 관한 연구는 국제 기구인 ISO, CCITT를 중심으로 하여 활발히 진행되고 있다. 본고에서는 ISO 의 subgroup B 를 중심으로 연구되고 있는 FDT인 ESTELLE를 중심으로 하여 ESTELLE의 기본 개념 및 ESTELLE프로그램의 구성에 대하여 소개하고자 한다.

• Proceedings of the CALSEC Conference
• /
• 1998.10b
• /
• pp.365-373
• /
• 1998

인터넷의 발달로 인해 조직 안의 마케팅, 광고, 조달, 판매, 서비스 제품 기획 등의 각 부분들간의 전자상거래와 조직간의 전자상거래, 그리고 빠르게 변화하는 기회를 잡기 위해 모인 기업의 컨소시엄의 형태인 가상기업에 대한 관심이 고조되고 있다. 이러한 조직내/조직간의 전자상거래와 가상기업에서 수행되어야 하는 비즈니스 프로세스를 통합, 향상시키기 위한 활동이 웍플로우 시스템이다. 웍플로우 관리 시스템은 기업의 비즈니스 프로세스를 정의하고 수행하며, 이를 추적하고 리엔지리어링한다. 하지만, 비즈니스 프로세스는 오랜 수행 기간과 복잡한 비즈니스 규칙등으로 인해 정확하고 신뢰적으로 수행하는 데에 많은 어려움을 가지며, 따라서 웍플로우 관리시스템은 비즈니스 프로세스의 자동화 및 개선을 위해서 작업 수행의 정확성과 신뢰성을 제공할 수 있어야 한다. 본 논문은 Event-Condition-Action(ECA) 규칙을 사용하여 비즈니스 프로세스를 올바르고 신뢰도 있게 정의ㆍ수행ㆍ분석ㆍ개선할 수 있는 트랜잭션의 지원을 위한 통합적이고 체계적인 프레임워크를 제시하고자 한다. 또한 웍플로우 모델과 그에 수반되는 오류 모델을 함께 제시하고 Petri Net으로 비즈니스 프로세스를 분석하는 방법론을 제시하고자 한다.

• IE interfaces
• /
• v.13 no.1
• /
• pp.92-99
• /
• 2000

Conflicts and interruptions caused by resource failures and rush orders require a nonlinear dynamic production management. Generally the PP&C systems used in industry presently do not meet these requirements because of their rigid concepts. Starting with the grasp of the disadvantages of current approaches, this paper presents a control structure that enables system to react to various malfunctions using a planning tolerance concept. Also, production processes are modeled by using Fuzzy-Petri-Net modeling tool in other to handle the complexity of job allocation and the existence of many disparities. On the basis of this model the developed system support the short-term shop control by rule based decision.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.82-85
• /
• 2004

This paper proposes the development of delay compensator to minimize performance degradation caused by time delays in network-based real-time control systems. The delay compensator uses the time-stamp method as a direct delay measuring method to measure time delays generated between network nodes. The delay compensator predicts the network time delays of next period in the views point of time delays and minimizes performance degradation from network through considering predicted time delays. Control output considering network time delays is generated by the defuzzification of probable time delays of next period. The time delays considered in the delay compensator are modeled by using a timed Petri net model. The proposed delay prediction mechanism for the delay compensator is evaluated through some simulation tests by measuring deviation of the predicted delays from simulated delays.