• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1263-1268
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• 2011

Rail infrastructure manager and operators shall establish emergency response plans. Emergency Response Planning Activities expanded coincidence events should be modeled. Identify the emergency response organization for the purpose of knowledge is required. In other words, control concepts and skills needed core elements. Structured analysis & design technic methodology is Compared with other modeling techniques through a simple graphical model is visualized. The information contained in a model real problems that considering the state of the system activities, so that knowledge acquired in situations where the modeling becomes possible. In this paper, using structured analysis techniques, infrastructure deployment model of the proposed features. In addition to emergency response planning in the 1960s in Germany, Karl Petrie (Carl Petri) devised various means of modeling the situation presents a Petri net model.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1897-1902
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• 2008

The computer system is used in many application domains and any system error in these domains may either cause critical loss or threaten environment or human life. Though examples of these domains can be found in many areas, the system, which is used in domains for carrying passengers including rolling stocks in particular, is expected to show satisfactory operation all the time. The relay control logic, which is used in rolling stocks, is complex in hardware and occupies considerably large volume. Nevertheless, it has been used for a long time, to let the system safely operate even in the occurrence of an error in the computer system. However, the relay control logic circuit is so complex that the analysis of proper circuit operation and interlocking tends to be dependent only on the designer's experiences instead of being systematically performed. Especially, the analysis following a change, addition and deletion of a previous circuit according to the requirements from a source of demand is significantly limited. In this paper, the accuracy of relay control logic is verified by the use of properties of Petri Net model. In addition, how main circuit breaker (MCB) control circuit is modeled and analyzed by the design methodology is shown.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1186-1190
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• 1995

This paper is focused on the formulation of explicit closed-form functions describing the performance measures of the general flexible manufacturing system (FMS)according to the strategy of material handling system(MHS). the performance measures such as the production rate, the production lead-time and the utilization rate of the general FMS are expressed, respectively, as the explicit closed-form functions of the part processing time, the service rate of the material handling system (MHS) and the number of machine tools in the FMS. For this, the gensral FMS is presented as a generalized stochastic Petri net model, then, the moment generating function (MGF) based approach is applied to obtain the steady-state probabity formulation. Based on the steady-state formulation, the explicit closed-form functions for performance measures of the probability FMS can be obtained. Finally, the analytical results are compared with the Petri net simulation results to verify the validity of the suggested method. The paper is of significance in the sense that it provides a comprehensive formula for performance measures of the FMS even to the industry engineers and academic reademic resuarchers who have no background on Markov chain analysis method or Petrinet modeling

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1254-1256
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• 1996

Design methods for sequence flow controllers play an important role in industrial automation. To design a flexible, reusable, and maintainable control software has become a key issue nowadays. Petri net has been emerging as an important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems recently. This paper describes an international standard of programming languages for programmable logic controllers, IEC 1131-3 SFC( Sequential Function Chart), and the sequence flow control method for an SFC using a Petri net-like model.

• Journal of Korean Society for Quality Management
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• v.31 no.3
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• pp.114-125
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• 2003

In this paper, we deal with the problem of modeling of agent-based robot manufacturing cell. Its role is becoming increasingly important in automated manufacturing systems. For Object Oriented & Queueing Petri Nets (OO&QPNs), an extended formalism for the combined quantitative and qualitative analysis of different systems is used for structure and performance analysis of mobile robotic cell. In the case study, the OO&QPN model of a mobile robotic cell is represented and analyzed, considering multi-class parts, non-preemptive priority and alternative routing. Finally, the comparison of performance values between Shortest Process Time (SPT) rule and First Come First Serve (FCFS) rule is suggested. In general, SPT rule is most suitable for parts that have shorter processing time than others.

• Journal of Korea Multimedia Society
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• v.2 no.2
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• pp.200-216
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• 1999

In this paper, we propose a BTPN (Beta-distributed Timed Petri Net) model which is not only an effective multimedia synchronization and authoring specification model, but also a direct control model for playout of a title. Methods of specification of relationships among all media objects in a title by using the BTPN structure and language, as well as methods of analysis of the BTPN by means of a Remaining Timed Reachability Graph and Timing diagram, are proposed. A concept of critical object path, coming from PERT/CPM, is useful for modeling the uncertainty of playout of a multimedia title and editing of title.

• Proceedings of the Korea Society for Simulation Conference
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• 1992.10a
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• pp.12-12
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• 1992

This paper proposes an analysis method of Petri nets (PNs) using the relational algebra (RA). More specifically, we represent PNs in relations of the relational model. Based on such representation, we first develop an algorithms for analyzing properties of PNs, such as boundedness, conservation, coverability, reachability, and liveness. The advantage of this approach is as follows: First, the algorithms represented by RA can be easily converted to a query language such as SQL of the widely used, commercial relational database management systems (DBMSs). Second, we can alleviate the problem of state space explosion because relational DBMSs can handle large amounts of data efficiency. Finally, we can use the DBMS's query language to interpret the Petri nets and make simulation.

• The Journal of Society for e-Business Studies
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• v.14 no.1
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• pp.35-56
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• 2009

Many process modeling techniques, such as Petri-net, UML Activity Diagram, and EPC, are used to design process models. In this paper, we analyze ubiquitous process design based on workflow patterns. In particular, we focus on process design using active rules that have the form of Event-Condition-Action, and deal with the WS-ECA language, which was devised for ubiquitous web services coordination. We first check whether workflow patterns can be designed with ECA rules, and we then provide WS-ECA representations for ECA rules of the patterns. The contribution of this paper is that ECA rule-based process models were presented based on workflow patterns and they can be a guideline for ubiquitous process modeling.

• The Journal of the Korea Contents Association
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• v.3 no.4
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• pp.55-62
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• 2003

In this paper, a call admission contro(cac) technique is proposed to reduce the dropping probabilities of handoff calls in wireless networks while guaranteeing QoS to the users. The proposed technique is based on the estimated effective load for the target eel if a call is accepted. When the estimated effective load is higher than a predetermined threshold, a nu call is blocked and a handoff call is queued irrespective of the availability channels. The SRN, an extended Stochastic Petri Net, modes are constructed to compare the performance of the techniques. The SRN uses rewards concepts instead of the complicate numerical analysis required for the Markov chain modes. As a result, the SRN modeling techniques provide an easier way to carry out performance analysis for call admission control and channel allocation.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.115-122
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• 2004

Software system modeling has a goal for finding and solving system's problems by describing and analyzing system model in formal notations. Petri nets, as graphical formalism, have been used in describing and analyzing the software systems such as parallel systems, real-time system, and protocols. In the analysis of Petri nets, general system properties such as deadlock and liveness are analyzed by the reachability analysis. On the other side, specific properties such as functional requirements and constraints are checked by model-checking. However, since these analysis methods are based on enumeration of ail possible states, there nay be state explosion problem, which means that system states exponentially increase as the size of system is larger. In this paper, we propose a new method for mechanically checking system properties with avoiding state explosion problem. At first, system properties are described in property nets then the system model and the property net are composed and analyzed. In the compositional analysis, system parts irrelevant to the specific property are reduced to minimize the analysis domain of the system. And it is possible to mechanically check whether a specific property is satisfied or not.