• 한국시뮬레이션학회논문지
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• 제27권3호
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• pp.23-36
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• 2018

이산사건시스템명세(DEVS) 형식론은 이산사건시스템을 모듈러하고 계층적으로 모델링할 수 있는 잘 정의된 의미론을 제공하고 있어 이산사건시스템 모델링 시뮬레이션 (M&S)에 많이 사용되어 왔다. 이러한 수학적 표현 대신에 DEVS 다이어그램은 복잡한 시스템을 보다 직관적이며 편리한 표현력을 제공한다. 본 논문은 DEVS 다이어그램을 이용하여 표현된 모델을 시뮬레이션 코드로 체계적으로 구현하며 검증하는 DEVS 클린룸 프로세스를 제안하였다. 구체적으로, 주어진 다이어그램 모델의 적합성 검사, 테이블 DEVS 모델로의 변환, 마지막으로 시뮬레이션 소스코드로 변환하는 방법과 역으로 추적성을 기반으로 한 검사기법을 통해 정적 검증하는 구체적인 방법을 제시하였다. 간단한 예제를 통해 제안된 프로세스를 적용하는 구체적인 방법을 설명하였으며, 적용사례 통해 제안된 기법이 실용적으로 적용 가능한 효과적인 프로세스임을 확인하였다.

• 한국군사과학기술학회지
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• 제10권1호
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• pp.78-85
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• 2007

A gun is still one of the major weapons of a combat ship. To assess the ship's fire control capability which is influenced by tracking system, fire control algorithm, gun, the ship itself, target behavior, environment and engagement situation, simulation system for gun-oriented engagement for surface ship is needed. This paper proposes the process for designing and implementing a gun-oriented engagement simulation system using DEVS(Discrete Event Simulation Specification), which is a formalism based on the set theory. It consists of the following activities : 1) analyzing the characteristics of a gun-oriented engagement, 2) constructing the deterministic model of the combat ship of study with DEVS, 3) modeling properties of each entity showing as stochastic errors. With this process, the gun-oriented engagement simulation system is developed and applied for the combat system under development.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.196-197
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• 2014

Low carbon construction is an important operation management goal such as cost, time, and quality in construction community. This paper introduces a system which measures the variability of carbon dioxide amounts. First, this system allows creating construction operation models of which the level of detail is breakdown into the work task level. Second, the system implements sensitivity analysis along with a ranges of resources that are allocated in an operation model. It facilitates to find the optimal resource combination using the operation performances such as the amount of emissions, operation completion time, and cost. Lastly, it identifies the best fit probability distribution functions of performance criteria given a certain resource combination. It allows project manager to query the percentages to complete the operation within a limitation specified by the system users.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.158-159
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• 2016

Construction project consists of several stages such as planning, design, construction, operation/maintain, etc. Decisions made in the planning and design stage have a significant impact on the construction and operation/maintain stages. Identifying key resources contributing to duration and cost of design alternatives is an important measure to achieve effective coordination between design and construction. This study proposes a method which finds an optimal design alternative by taking into account of resource planning, expected duration, and cost in construction stage. Base on literature review relative to the assessment of design alternatives, a method which predicts required resources, duration, and cost of the design alternative is established. Then, a method that identifies an optimal design alternative based on the preference of a certain project criteria is developed. Finally, a case study is presented.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2000년도 추계학술대회 논문집
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• pp.28-33
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• 2000

This article describes the application of discrete event simulation in a process industry (coffee manufacturing) as a daily production-scheduling tool. A large number of end products (around 300), sporadic demand, and limited shelf life of coffee (90 days) make it difficult to generate feasible production schedules manually. To solve this problem an integrated system was developed incorporating discrete event simulation methodology into scheduling process. The integrated system is comprised of two components: a scheduling program and a simulation model. The scheduling program is used to generate daily schedules for roasting, grinding, and packing coffee. The simulation model uses the generated schedules to simulate the production of coffee and regenerates a modified production schedule. In this paper, each of the components will be described in detail, evaluated in terms of performance factors, and validated with a set of real production data. Although this article focuses on a specific system, we will share our experiences and intuitions gained and encourage other process industries to develop simulation-based scheduling tools.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1359-1363
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• 2009

The object of this research is to develop a simulation system for earthmoving operations in consideration of the impact of congestion in-between equipment and existing traffic flow around the site. The congestion in-between equipment and traffic flow affect work productivity. The conventional discrete event simulation, however, has limitations in simulating the flow of construction equipment. To consider the impact of congestion in-between equipment and existing traffic flow, in this paper, a multi-agent based simulation model that can realize characteristics of truck behavior more accurately to consider the impact of congestion was proposed. In this simulation model, multiple agents can identify environmental changes and adapt themselves to the new environment. This modeling approach is a better choice for this problem since it describes behavioral characteristics of each agent by sensing changes in dynamic surroundings. This study suggests a detailed system design of the multi-agent based simulation system.

• 대한산업공학회지
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• 제42권2호
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• pp.151-164
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• 2016

In this paper, we deal with a risk analysis for an IPS (Integrated power system) and propose a simulation model combining the fault tree and event tree in order to estimate the system availability and risk level, together. Firstly, the basic information such as operational scenarios, physical structure, safety systems is explained in order to make the fault tree and event tree of the IPS. Next, we propose a discrete-event simulation model using a next-event time advance technique to advance the simulation time. Also the state transition and activity diagrams are explained to represent the relationship between the objects. By numerical examples, the redundancy allocation is considered in order to decrease the risk level of the IPS.

• Advances in Computational Design
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• 제3권4호
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• pp.405-418
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• 2018

Building Information Modelling (BIM) and Discrete Event Simulation (DES) are tools widely used in the context of the construction industry. While BIM is used to represent the physical and functional characteristics of a facility, DES models are used to represent its construction process. Integrating both is beneficial to those interested in the field of construction management since it has many potential applications. Game engines provide a human navigable 3D virtual environment in which the integrated BIM and DES models can be visualised and interacted with. This paper reports the experience obtained while developing a simulator prototype which integrates a BIM and a DES model of a single construction activity within a commercial game engine. The simulator prototype allows the user to visualise how the duration of the construction activity is affected by different input parameters interactively. It provides an environment to conduct DES studies using the user's own BIM models. This approach could increase the use of DES technologies in the context of construction management and engineering outside the research community. The presented work is the first step towards the development of a serious game for construction management education and was carried out to determine the suitable IT tools for its development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권5호
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• pp.2186-2203
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• 2020

Security administrators of companies and organizations need to come up with proper countermeasures against cyber-attacks considering infrastructures and security policies in their possession. In order to develop and verify such countermeasures, the administrators should be able to reenact both cyber-attacks and defenses. Simulations can be useful for the reenactment by overcoming its limitations including high risk and cost. If the administrators are able to design various scenarios of cyber-attacks and to develop simulation models from their viewpoints, they can simulate desired situations and observe the results more easily. It is challenging to simulate cyber-security issues, because there is lack of theoretical basis for modeling a wide range of the security field as well as pre-defined basic components used to model cyber-attacks. In this paper, we propose a modeling method for cyber-security simulations by developing a basic component and a composite model, called Abstracted Cyber-Security Unit Model (ACSUM) and Abstracted Cyber-security SIMulation model (ACSIM), respectively. The proposed models are based on DEVS(Discrete Event systems Specification) formalism, a modeling theory for discrete event simulations. We develop attack scenarios by sequencing attack behaviors using ACSUMs and then model ACSIMs by combining and abstracting the ACSUMs from a security perspective. The concepts of ACSUM and ACSIM enable the security administrators to simulate numerous cyber-security issues from their viewpoints. As a case study, we model a worm scenario using ACSUM and simulate three types of simulation models based on ACSIM from a different security perspective.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1990년도 춘계공동학술대회논문집; 한국과학기술원; 28 Apr. 1990
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• pp.22-31
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• 1990

본 논문에서는 컴퓨터 통신 프로토콜의 모델링과 시뮬레이션에 관한 이론적 인 연구를 하였다. 먼저 통신 프로토콜의 정의와 기능을 설명하였고 통신 프 로토콜을 위한 모델을 분류하였다. 또한, 통신 프로토콜의 모델 중에 Timed Petri Net(TPN) 모델에 시간함수 .tau.를 부여함으로써 TPN을 구조적으로 정의하였으며 TPN Based 모델의 문제점을 보완하기 위하여 시스템 시뮬레 이션 분야의 이산사건 시스템 명세(DEVS:Discrete Event Simulation) 개념 을 도입하였다. 중요한 연구 결과로서 TPN모델이 DEVS모델이라는 정리를 제시하고 증명하였다. 이 정리에 따르면, TPN모델을 시뮬레이션 할 때 시뮬 레이션을 위해 모델을 설계할 필요없이 DEVS모델로 변환하여 사용함으로써 시뮬레이션을 수행할수 있다.