• 한국시뮬레이션학회논문지
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• 제3권1호
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• pp.65-74
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• 1994

In the steady-state simulation, it is important to identify initialization bias for the correct estimates of the simulation model under study. In this paper, the methods from chaos theory are applied to the determination of truncation points in the simulation data for controlling the initial bias. Two methods are proposed and evaluated based on their effectiveness for estimation the average waiting time in M/M/1($\infty$) queueing model.

• 한국시뮬레이션학회논문지
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• 제12권4호
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• pp.83-94
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• 2003

Managing a call center is a complex and diverse challenge. Call center becomes a very important contact point and a data ware house for successful CRM. Improving performance of call center is critical and valuable for providing better service. In this study we applied forecasting technique to estimate incoming calls and ProModel based simulation model to enhance performance of a mobile telecommunication company's call center. The simulation study shows reduction in managing cost and better customer's satisfaction.

• 정보보호학회논문지
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• 제11권2호
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• pp.13-26
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• 2001

본 논문은 계층 구조적이고 모듈화 된 모델링 및 시뮬레이션 프레임워크를 이용한 네트워크 보안 모델링과 시뮬레이션 기법의 연구를 주목적으로 한다. 최근, Howard와 Amroso는 사이버 공격, 방어 및 결과에 대한 원인-결과 모델을 개발하였다. 또한, Cohen은 원인-결과 모델을 이용하여 단순한 네트워크 보안 시뮬레이션 방법론을 제안한 바 있으나, 복잡한 네트워크 보안과 모델과 모델 기반의 사이버 공격에 대한 시뮬레이션은 불가능한 실정이다. 따라서, 본 논문에서 는 인공지능의 기호적 형식론과 시뮬레이션의 동역학적 형식론을 체계적이고 통합한 System Entity Structure/Model Base(SES/MB)을 통하여 계층 구조적이고 모듈화 된 네트워크 보안 모델링 및 시뮬레이션 방법론을 제안하고 사이버 공격 시나리오를 이용한 사례연구를 통하여 타당성을 검증하였다.

• 대한산업공학회지
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• 제33권2호
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• pp.191-200
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• 2007

We propose the QoS (Quality of Service) assurance model for AMR (Adaptive MultiRate) voice users considering the capacity and service quality jointly in downlink WCDMA system. For this purpose, we introduce a new system performance measure and the number-based AMR mode allocation scheme. The proposed number-based AMR mode allocation can be operated only with the information of total number of ongoing users. Therefore, it can be more simply implemented than the existing power-based allocation. The proposed system performance measure considers the stochastic variations of AMR modes of ongoing users and can be analytically obtained using CTMC (Continuous Time Markov Chain) modeling. In order to validate the proposed analytical model, a discrete event-based simulation model is also developed. The performance measure obtained from the analytical model is in agreement with the simulation results and is expected to be useful for parameter optimization.

• 디지털산업정보학회논문지
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• 제17권1호
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• pp.25-34
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• 2021

Availability is one of the important factor for developing weapon system, because it indicates the mission capability and sustainable life cycle management of weapon system. Recently, as weapon system becomes more advanced and more complex, availability estimation becomes more important to reduce the life cycle cost of weapon system. Modeling and simulation(M&S) is useful method to describe the availability of complex weapon system applying operational environment and maintenance plan. Especially agent based model(ABM) has the strength to describe interactions between agents and environments in complex system. Therefore, this paper presents the availability estimation of weapon system using agent based model. The sample data of part list and reliability analysis is applied to build availability estimation model. User agent and mechanic agent are developed to illustrate the behavior of operation and maintenance using formal specification. Storage reliability is applied to describe failure of each parts. The experimental result shows that this model is quite useful to estimate availability of weapon system. This model may estimate more reasonable availability, if full scale data of weapon system and real field data of operation is provided.

• 대한조선학회논문집
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• 제46권6호
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• pp.641-649
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• 2009

There were many simulation models that made for validation of industrial environment and estimate of efficiency to be constructed. And there will be more simulation models made for same reason, too. Already, there have been a lot of simulation models in industry field and scholar labs. To reuse these simulation models, it is necessary to find common properties and make the high abstract simulation model. Based on this idea, this study shows to define the high abstract simulation model to be able to specialize in need and to make the software framework for connecting the specific simulation model to the abstract model. And it is held up as the example that applying the simulation framework to the Ship Panel Block shop simulation model.

• 제어로봇시스템학회논문지
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• 제2권3호
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• pp.209-219
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• 1996

Fieldbus provides a real-time data communication among field devices in the process control and manufacturing automation systems. In this paper, a Petri Net model of the 1993 draft of IEC/ISA fieldbus which is proposed as an international standard of fieldbus network is developed. Based on the Petri Net model, discrete-event simulation model of IEC/ISA fieldbus network is developed. This paper evaluates the network induced delay in the data link layer of IEC/ISA fieldbus using the simulation model. In addition, an integrated discrete-event/continuous-time simulation model of fieldbus system and distributed control system is developed. This paper investigates the real-time data processing capability of IEC/ISA fieldbus and the effect of network-induced delay to the performance of control system.

• 한국시뮬레이션학회논문지
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• 제6권1호
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• pp.25-40
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• 1997

This study deals with an autonomous generation of simulation codes for the design of processes of c CIM system based on the concept of model transformation. We assume we have a functional model of an organization which is developed using the well-known IDEF0 methodology. Then, a modeling methodology, called PROWD(PRocess flOW Description), is suggested to develop the flow processes of the organization. To Derive simulation specifications for the transformed PROWD model, we define a module of a "unit system" for each activity of PROWD model. Then specifications for system entities and resources are derived from input/control/mechanism/output and entity flows of PROWD model. Entitiy queues are defined from the sates and events of unit systems. Finally, SIMAN model frame is generated from those specifications through a suggested algorithm. The implementability and validity of the proposed approach is tested by developing a prototype of a computer-assisted design system on the operation processes of FMS installed at SNU-ASRI (Seoul National University-Automation and Systems Research Institute).nstitute).

• 한국시뮬레이션학회논문지
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• 제23권4호
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• pp.21-29
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• 2014

일반적으로 시뮬레이션 프로젝트는 목적에 부합되는 수준에서 연구 대상 시스템과 유사하게 작동되는 모델을 개발해야 하기 때문에 시간과 비용이 많이 소요된다. 따라서 적절한 개념 모델 설계와 이를 바탕으로 시뮬레이션 모델을 자동 생성하여 모델 개발 과정의 시행착오를 최소화함으로써 모델링 시간을 단축하기 위한 연구가 요구되고 있다. 본 논문에서는 실무에서 많이 사용되고 있는 Microsoft Excel과 Visio를 활용하여 개념 모델을 개발하고 이를 Arena 모델로 자동으로 변환하는 툴을 제안하였다. 예제를 이용하여 본 논문의 모델 자동 생성 툴의 효용성을 보였다.

• Interaction and multiscale mechanics
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• 제2권4호
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• pp.353-374
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• 2009

A new seamless multiscale simulation was developed for coupling the continuum model with its molecular dynamics. Kriging-based Finite Element Method (K-FEM) is employed to model the continuum base of the entire domain, while the molecular dynamics (MD) is confined in a localized domain of interest. In the coupling zone, where the MD domain overlaps the continuum model, the overall Hamiltonian is postulated by contributions from the continuum and the molecular overlays, based on a quartic spline scaling parameter. The displacement compatibility in this coupling zone is then enforced by the Lagrange multiplier technique. A multiple-time-step velocity Verlet algorithm is adopted for its time integration. The validation of the present method is reported through numerical tests of one dimensional atomic lattice. The results reveal that at the continuum/MD interface, the commonly reported spurious waves in the literature are effectively eliminated in this study. In addition, the smoothness of the transition from MD to the continuum can be significantly improved by either increasing the size of the coupling zone or expanding the nodal domain of influence associated with K-FEM.