• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1025-1028
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• 2010

This paper presents a new approach to analyze the stability of dynamic competitive markets within the framework of supervisory control of discrete event systems. A competitive market is representative of free market economy where it is well known that an invisible hand (also referred to as Walrasian auctioneer) always achieves an equilibrium of demand and supply. Upon the framework of supervisory control theory, this paper shows that Walrasian auctioneer is a stabilizing supervisor for a convergent competitive market, however a non-convergent competitive market (e.g. a free market under economic bubble and depression) controlled by Walrasian auctioneer may not be stable.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.2
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• pp.119-126
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• 2001

시간 페트리 네트는 실시간 값을 갖는 이산사건 시스템을 모델링하고 해석하기 위한 방법중 하나이다. 시간 페트리 네트는 각 트랜지션에 대하여 두 개의 시간 값, 최초 발화 시간 $\alpha$$_{i}$와 최종 발화 시간 $\beta$$_{i}$를 갖는다. 본 논문에서는 최적 발화 시간을 결정하기 위하여 퍼지 이론을 적용한 퍼지 트랜지션 시간 페트리 네트를 제안하였다. 퍼지 트랜지션 시간 페트리 네트의 트랜지션 점화 시간 ${\gamma}$$_{i}$는 고정 최초 발화 시간 $\alpha$$_{i}$와 고정 최종 발화 시간 $\beta$$_{i}$ 사이에서 어떠한 복잡한 계산 절차나 임의의 조건 없이 입력정보를 이용한 퍼지 이론으로부터 결정된다. 교차로에서 교통 신호제어기는 퍼지 트랜지션 시간 페트리 네트에 의하여 모델링되고 해석되었다. 퍼지 트랜지션 시간 페트리 네트의 중요한 특성은 교통 신호기의 모델링과 시뮬레이션에 의해서 보여진다. 의해서 보여진다.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.4
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• pp.304-312
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• 2011

In an oligopolistic market, only a few firms account for most or all of total production, e.g., automobile, steel, and computer industries. For a dynamic oligopolistic market with two firms competing in quantities, we show that supervisory control theory of discrete event systems provides a novel approach to solve the dynamic oligopoly problem with the aim of maximizing the profits of both firms. Specifically, we show that the controllability, observability, and nonblocking property (which are the core concepts in supervisory control theory) are the necessary and sufficient conditions for two oligopolistic firms in disequilibrium to eventually reach equilibrium states of maximizing the profits of both firms.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.632-638
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• 1997

The growing number of electronic components used in automobiles has given rise to problems concerning the increasing number, size and weight of the wiring harnesses. As an approach to resolve these problems, multiplexed wiring systems using automotive communication protocol such as Controller Area Network(CAN), Advanced PALMNET and J1850 have been developed by many automobile companies. In order to compare these protocols quantitatively, this paper presents the performance evaluation of CAN and Advanced PALMNET via discrete event simulation. Through numerous simulation experiments, several important quantitative performance factors such as the probability of a transmission failure, average system delay(data latency), and throughput have been evaluated.

• Journal of the Korea Society for Simulation
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• v.10 no.3
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• pp.15-30
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• 2001

Hybrid simulation may employ different types of simulation based on which models in different system types are developed. The simulation requires simulation time synchronization and data exchange between such simulators, which is called simulators interoperation. This paper develops such interoperable simulation environments for modeling and simulation of hybrid systems whose components consist of continuous and discrete event systems. The environments, one for centerized and the other for distribute, support interoperation between a discrete event simulator of DEVSim++ and a continuous simulator of MATLAB. The centerized environment, HDEVSim++, is developed by extending the sxisting DEVSim++ environment; the distributed environment, HDEVSimHLA, is developed using the HLA/RTl library. Verification of both environments is made and performance comparison between the two using a simple example is presented. .

• 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.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.1
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• pp.9-17
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• 2006

This paper deals with a discrete simulation optimization method for designing a complex probabilistic discrete event simulation. The developed algorithm uses the configuration algorithm that can change decision variables and the stopping algorithm that can end simulation in order to satisfy the given objective value during single run. It tries to estimate an auto-regressive model for evaluating correctly the objective function obtained by a small amount of output data. We apply the proposed algorithm to M/M/s model, (s, S) inventory model, and known-function problem. The proposed algorithm can't always guarantee the optimal solution but the method gives an approximate feasible solution in a relatively short time period. We, therefore, show the proposed algorithm can be used as an initial feasible solution of existing optimization methods that need multiple simulation run to search an optimal solution.

• ICROS
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• v.5 no.4
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• pp.29-41
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• 1999

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.570-571
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• 1999

• Korean Management Science Review
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• v.11 no.1
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• pp.107-115
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• 1994

Stochastic manufacturing systems are generally formulated as performance models of discrete event systems. In this paper, logical models(as opposed to performance models) of kanban systems are presented which are deterministic and untimed but not stochastic and timed. As a result, the first and second order properties of kanban systems are showed which can be fruitfully applied to the analysis and design of kanban systems.