• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.939-943
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• 2001

PLC(programmable Logic Controller)s essential components of modern automation systems encompassing almost every industry. Ladder Diagrams (LD) have been widely used in the design of such PLC since the LD is suitable for the modeling of the sequential control system. However, the synthesis of LD itself mainly depends on the experience of the industrial engineer, which may results in unstructured or inflexible design. Hence, in this paper, we propose a ladder diagram conversion algorithm which systematically produces LDs for PLCs based on discrete event models to enhance the structured and flexible design mechanism.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.838-840
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• 1999

In this paper, modeling and analysis of discrete event systems by temporal logic frame works and petri net is considered. The reachability tree of the petri net can be used to solve the safeness, boundedness, conservation and coverability problems of discrete event systems. But the reachability tree of the petri net do not solve reachability and liveness problems in general. We proposed a method that synthesised the petri net and the temporal logic frameworks. This method slove some problems of petri net by logical representation of temporal logic frameworks.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.79-81
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• 2006

Simulation and physical implementation are both valuable tools in evaluating sensor network routing protocols, but neither alone is sufficient. In this paper, we present the implementation and analysis of sensor routing protocols on the discrete-event simulation system that allows existing nesC codes of sensor network routing protocols to be used to create a physical implementation of the same protocol. We have evaluated the Surge function of TinyOS through example implementations in the Ptolemy II of the unmodified codes and Direct-diffusion routing protocols using VIPTOS simulation models.

• Korean Journal of Computational Design and Engineering
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• v.19 no.1
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• pp.29-40
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• 2014

Conceptual Modeling is the process of abstracting a model from a real or proposed system. It is probably the most important aspect of a simulation study. Relate works show that the elementary developers devoted little time to understanding how the systems actually worked, namely they didn't build appropriate conceptual model. Thus, the result of simulation is inconsistent because it depends on developer's competence. Although many researchers suggested various techniques enabling developer to build conceptual model, there were several limitations. In this study, to overcome the limitations of existing techniques, we proposed COMBINE-DES (COnceptual Model BuildINg framEwork using ontology for Discrete Event Simulation). The COM-BINE-DES supports expediting the conceptual modeling with Solution ontology generated by Domain ontology and Simulation ontology. Moreover, it provides consistent simulation result regardless of repeated modeling.

• Journal of the Korea Society for Simulation
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• v.9 no.1
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• pp.39-54
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• 2000

Presented in this paper is a modeling and simulation methodology for 3 dimensional man-made systems. Based on DEVS(discrete event system specification) formalism[13], we propose GK-DEVS (geometrical and kinematic DEVS) formalism to describe the geometrical and kinematic structure and continuous state dynamics. To represent geometry and kinematics, we add a hierarchical structure to the conventional atomic model. In addition, we employ the "empty event" and its external event function for continuous state changing. In terms of abstract simulation algorithm[13], the simulation method of GK-DEVS, named GK-Simulator, is proposed for combined discrete-continuous simulation. Using GK-DEVS, the simulation of an FMS(flexible manufacturing system) consisting of a luring machine, a 3-axis machine and a RGV-mounted robot has been peformed.en peformed.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.590-592
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• 1997

A Discrete Event Dynamic System is a system whose states change in response to the occurrence of events from a predefined event set. A major difficulty in developing analytical results for the systems is the lack of appropriate modeling techniques. This paper proposes the use of Real-time Temporal Logic as a modeling tool for the analysis and control of DEDS. The Real-time Temporal Logic Frameworks is extended with a suitable structure of modeling hard real-time constraints. Modeling rules are developed for several specific situations. It is shown how the graphical model can be translated to a system of linear equations and constraints.

• Journal of the Korea Society for Simulation
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• v.1 no.1
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• pp.64-76
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• 1992

The DEVS(discrete event system specificaition) formalism specifies a discrete event system in a hierarchical, modular form. DEVSIM++ is a C++based general purpose DEVS abstract simulator which can simulate systems modeled by the DEVS formalism in a sequential environment. This paper describes P-DEVSIM++which is a parallel version of DEVSIM++ . In P-DEVSIM++, the external and internal event of DEVS models can by processed in parallel. For such processing, we propose a parallel, distributed optimistic simulation algorithm based on the Time Warp approach. However, the proposed algorithm localizes the rollback of a model within itself, not possible in the standard Time Warp approach. An advantage of such localization is that the simulation time may be reduced. To evaluate its performance, we simulate a single bus multiprocessor architecture system with an external common memory. Simulation result shows that significant speedup is made possible with our algorithm in a parallel environment.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.244-252
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• 2013

In this paper, we show that supervisory control theory of discrete event systems can be applied to analyze the problem of power in political economy. For this purpose, we introduce the decision mechanism of control inputs based on power, and the consequent behavior of a supervised system. Specifically, this paper presents the notion of power-controllability as a necessary and sufficient condition to achieve a common control objective of competing groups (local controllers). If the power-controllability is met, a modular system controlled by local controllers with power functions is not deviated from a common control objective of them.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.816-819
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• 1996

This paper focuses on development of simulation model for SAE J1850 and performance evaluation of a J1850 network. The simulation model has been developed by using discrete event simulation language. SAE J1850 is one of Class B network protocol for general data sharing applications. Through numerous simulation experiments, several important performance factors such as the probability of a successful transmission, average queue delay, and throughput have been evaluated.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.73.5-73
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• 2001

In this paper, we present a procedure to design the robust optimal supervisor which has the minimal cost in the sense of average for a given multiple-modelled discrete event system DES. In order to design the robust optimal supervisor, we extend the optimal supervisor design algorithm for a deterministic DES to the case of multiple-modelled DESs. In addition, using the proposed algorithm with modified costs of events and penalities of states, we can show whether a robust supervisor for a given multiple-modelled DES exists and design the minimally restricted robust supervisor.