• Proceedings of the Korea Society for Simulation Conference
• /
• 2001.10a
• /
• pp.405-424
• /
• 2001

Many simulation models have been built to facilitate simulation technique in designing, evaluating, and optimizing supply chains. Simulation is preferred to deal with stochastic natures existing in the supply chain. Moreover simulation has a capability to find local optimum value within each component through entire supply chain. Most of supply chain simulation models have been developed on the basis of discrete-event simulation. Since supply chain systems are neither completely discrete nor continuous, the need of constructing a model with aspects of both discrete-event and continuous simulation is provoked, resulting in a combined discrete-continuous simulation. In this paper, an architecture of combined modeling for supply chain simulation is proposed, which includes the equation of continuous portion in supply chain and how these equations are used in the supply chain simulation models. A simple example of supply chain model dealing with the strategic level of supply chain presented in this paper shows the possibility and the prospect of this approach.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.570-573
• /
• 2001

Safety is very important to operate nuclear power plant. To have the safety, nuclear power plant should be run without trouble. This paper presents the application of a failure diagnosis approach based on discrete event system theory to the Main Feedwater System for Safe Integral Reactor.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10b
• /
• pp.1240-1245
• /
• 1990

Intelligent Control is an extended paradigm that subsumes both control and AI paradigms, each of which is limited by its own abstractions. Autonomy, as a design goal, offers an arena where both control and AI paradigms must be applied -and a challenge to the viability of both as independent entities. We discuss hierarchical event-based control architectures in which AI and Control paradigms can be integrated within a model-based approach. In a niodel-based system, knowledge is encapsulated in the form of models at the various layers to support the predefined system objectives. Concepts are illustrated with a robotmanaged space-borne chemical laboratory.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.11
• /
• pp.1025-1028
• /
• 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 Korean Institute of Industrial Engineers
• /
• v.43 no.1
• /
• pp.12-18
• /
• 2017

This study presents a plant concept design for a smart factory which is mainly targeted to machine airplane parts. The plant layout is based on the TOC-DBR approach together with autonomous distributed factory control considered, while discrete event simulation is also performed in order to validate its layout. The resulting layout and its procedure turn out to be quite a useful guideline in realizing those smart factories especially for machining-oriented manufacturing industries.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2006.11a
• /
• pp.574-578
• /
• 2006

Simulation has considerable potential as the tool of construction management, but in the case of domestic, it is at an early stage applying simulation to micro-process assesment. For applying simulation to the construction process, much effort is needed to collect input data and to build the model including the characteristics of the fields. This study introduces the methodology to build the simulation model, then verifies the model with the operation data.

• Journal of the Korea Society for Simulation
• /
• v.10 no.2
• /
• pp.75-89
• /
• 2001

Many simulation models have been built to facilitate simulation technique in designing, evaluating, and optimizing supply chains. Simulation is preferred to deal with stochastic natures existing in the supply chain. Moreover simulation has a capability to find local optimum value within each component through entire supply chain. Most of supply chain simulation models have been developed on the basis of discrete-event simulation. Since supply chain systems are neither completely discrete nor continuous, the need of constructing a model with aspects of both discrete-event and continuous simulation is provoked, resulting in a combined discrete-continuous simulation. In this paper, an architecture of combined modeling for supply chain simulation is proposed, which includes the equation of continuous portion in supply chain and how these equations are used in the supply chain simulation models. A simple example of supply chain model dealing with the strategic level of supply chain presented in this paper shows the possibility and the prospect of this approach.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.4
• /
• pp.304-312
• /
• 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
• /
• v.3 no.6
• /
• pp.632-638
• /
• 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 Korean Data and Information Science Society
• /
• v.25 no.5
• /
• pp.1117-1125
• /
• 2014

In a longitudinal study, subjects can experience same type of events repeatedly. Also, there may exist intermittent dropouts resulting in repeated observation gaps during which no recurrent events are observed. Furthermore, when such observation gaps have incomplete forms caused by the unknown termination times of observation gaps, ordinary approaches result in biased estimates. In this study, we investigate the effect of ignoring observation gaps and propose methods to overcome this problem. For estimating the distribution of unknown termination times, an interval-censored mechanism is applied and two cases are considered. Simulation studies are carried out to evaluate the performance of the proposed method. Conviction data of young drivers with several suspensions are analyzed to illustrate the suggested approach.