• Proceedings of the Korea Society for Simulation Conference
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• 2002.11a
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• pp.125-130
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• 2002

본 연구는 DEVS를 기반으로 개발된 교통류 시뮬레이션 시스템인 $\ulcorner$I$^3$D$^2$ 교통류 시뮬레이션 시스템$\lrcorner$(이하 I$^3$D$^2$)의 검증을 그 목적으로 한다. I$^3$D$^2$는 본 연구진이 DEVS를 기반으로 개발한 범용 시뮬레이션 도구로써, 이미 서울시 강남 신호교차로와 내부순환로를 대상으로 하여 개발된 내용을 발표한 바 있다. I$^3$D$^2$는 헌재 단속류에서의 최적신호 생성 및 대기행렬 예측 문제, 그리고 연속류 시설의 용량 산정 문제등을 시뮬레이션 할 수 있다. 하지만 아직 문헌자료나 현장 데이터를 토대로 한 충분한 검증이 수행되지 못한 문제가 있다. 따라서 본 연구에서는 문헌자료를 토대로, I$^3$D$^2$를 검증한다. 이를 위하여 고속도로 또는 도시고속도로와 같은 연속 교통류의 대표적인 효과척도인 $\ulcorner$교통량 - 밀도 - 평균주행속도 (시간)$\lrcorner$ 간의 상관관계를 이용하여 미국 HCM과 우리나라의 도로용량편람에 정의되어 있는 기준을 토대로 I$^3$D$^2$ 검증을 수행하였다. 모델링은 서울시 올림픽대로의 양화대교 - 성산대교 - 가양대교 구간을 대상으로 했으며, 검증은 교통량에 따라 크게 3가지 교통류 상태(random, intermediate, constant)를 기준으로 시뮬레이션이 각각의 교통상태에서 예측한 평균주행시간의 정확도를 측정하면서 수행하였다. 검증 결과 random 상태에서는 문헌자료에 부합되는 예측결과를 보여주었으나, intermediate와 constant 상태에서는 문헌보다 다소 낮은 속도를 보여주었다 이러한 속도차는 추후 현장 데이터를 수집하여 보다 실질적인 검증을 통하여 조정되어야 할 것으로 판단된다.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.21-30
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• 2007

Simulation means modeling structures or behaviors of the various objects, and experimenting them on the computer system. And the major approaches are DEVS(Discrete Event Systems Specification). Petri-net or Automata and so on. But, the simulation problems are getting more complex or complicated these days, so that an intelligent agent-based is being studied. In this paper, we are describing an intelligent agent-based simulation tool, which can supports the simulation experiment more efficiently. The significances of our system can be described as follows. First, the system can provide some AI algorithms through the system libraries. Second, the system supports simple method of designing the simulation model, since it's been built under the Finite State Machine (FSM) structure. And finally, the system acts as a simulation framework by supporting user not only the simulation engine, but also user-friendly tools, such as modeler scriptor and simulator. The system mainly consists of main simulation engine, utility tools, and some other assist tools, and it is tested and showed some efficient results in the three different problems.

• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.33-46
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• 2020

The purpose of Electronic warfare is to disturbe, neutralize, attack, and destroy the opponent's electronic warfare weapon system or equipment. Suppression of Enemy Air Defense (SEAD) mission is aimed at incapacitating, destroying, or temporarily deteriorating air defense networks such as enemy surface-to-air missiles (SAMs), which is a representative mission supported by electronic warfare. This paper develops a simulator for analyzing the effectiveness of SEAD missions under electronic warfare support using C++ language based on the DEVS (Discrete Event Systems Specification) model, the usefulness of which has been proved through case analysis with examples. The SEAD mission of the friendly forces is carried out in parallel with SSJ (Self Screening Jamming) electronic warfare under the support of SOJ (Stand Off Jamming) electronic warfare. The mission is assumed to be done after penetrating into the enemy area and firing HARM (High Speed Anti Radiation Missile). SAM response is assumed to comply mission under the degraded performance due to the electronic interference of the friendly SSJ and SOJ. The developed simulator allows various combinations of electronic warfare equipment specifications (parameters) and operational tactics (parameters or algorithms) to be input for the purpose of analysis of the effect of these combinations on the mission effectiveness.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.97-105
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• 2015

This paper is to analyze the efficiency of power consumption in logistic systems that are based on self-driving roller conveyors by the simulation technology. The improvement of the efficiency brings advantages for reducing greenhouse gas emission and logistics costs. A self-driving roller conveyor is operated only when products are loaded on itself. Thus, the self-driving roller conveyor systems consume less electric power than continuous-driving roller conveyor systems. In this paper, we design a DEVS (Discrete-Event based System) based simulation model and construct self-driving roller and continuous-driving roller conveyor models. For the verification and validation of the designed simulation system and conveyor models, we model a corresponding logistic model for the experimental environment and compare between the model and a real system. The main objective of this paper is to describe the power consumption advantage of self-driving roller conveyor based logistic systems using a simulation method.

• Journal of Digital Contents Society
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• v.3 no.2
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• pp.255-264
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• 2002

Multimedia is now applied to various real worlds. In particular, the focus of CSCW(Computer Supported Cooperated Work) for multimedia education system has increased. DOORAE is a framework for supporting development of applications running on distributed multimedia environment and multimedia distance education system. EDA is a system is able to detect automatically a software error based on distributed multimedia. It has been designed and implemented for construction and experiment of effective DOORAE environment. It detects an error by polling periodically the process with relation to session. Conventional method detects an error by polling periodically all the process. This papaer explains a performance analysis of an error detection system running on distributed multimedia environment using the rule-based SES and DEVS modeling and simulation techniques. In DEVS, a system has a time base, inputs, states, outputs, and functions.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.11a
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• pp.91-97
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• 2002

DEVS 형식론을 비롯한 모듈러한 시스템 모델링 방법은 복잡한 시스템을 모델링 할 때 유리하다. 반면에, 모듈러한 구성요소 모델들은 타 구성요소 모델의 상태 정보를 참조, 복사함으로써 빈번한 메시지 전달을 야기 시켜 시뮬레이션 속도가 저하되는 단점이 있다. 모델 합성법(Composition)은 여러 개의 요소모델들을 하나로 통합시키는 연산으로서 시스템 검증 분야에서 많이 사용되어져 왔다. 본 논문은 모델 합성법을 이용하여 구성요소 모델들 간에 주고받는 메시지 수를 줄이고 시뮬레이션 속도를 개선시키는 방법을 제안한다. 간단한 예제를 통하여 제안한 방법을 자세히 보여주고자 한다.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.04a
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• pp.232-236
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• 1999

Codesign 방법론은 하드웨어와 소프트웨어가 공존하는 시스템을 설계할 때 이드의 설계를 각각의 특성에 맞는 방법을 사용함으로써 효율적인 디자인방법을 제공한다. 전체 시스템의 동작 및 성능을 검증하기 위해서는 다른 방법으로 개발된 하드웨어와 소프트웨어를 같이 시뮬레이션해야 하는데 이를 통합시뮬레이션(Co-simulation)이라고 한다. 하드웨어와 소프트웨어를 개발하는 방법이 다르기 때문에 야기되는 통합의 문제점을 해결하기 위하여 DEVS(Discrete Event System Specification)에 기반한 중간단계형태를 통한 변환방법론을 제시하고 이를 사용하여 C++ 모델과 Verilog HDL 모델간의 통합시뮬레이션을 구현함으로써 효용을 보이고자 한다.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.440-443
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• 2001

As inter-network traffics grows rapidly, the router systems as a network component becomes to be capable of not only wire-speed packet processing but also plentiful programmability for quality services. A network processor technology is widely used to achieve such capabilities in the high-end router. Although providing two such capabilities, the network processor can't support a deep packet processing at nominal wire-speed. Considering QoS may result in performance degradation of processing packet. In order to achieve foster processing, one chipset of network processor is occasionally not enough. Using more than one urges to consider a problem that is, for instance, an out-of-order delivery of packets. This problem can be serious in some applications such as voice over IP and video services, which assume that packets arrive in order. It is required to develop an effective packet processing mechanism leer using more than one network processors in parallel in one linecard unit of the router system. Simulation analysis is also needed for verifying the mechanism. We propose the packet processing mechanism consisting of more than two NPs in parallel. In this mechanism, we use a load-balancing algorithm that distributes the packet traffic load evenly and keeps the sequence, and then verify the algorithm with simulation analysis. As a simulation tool, we use DEVSim++, which is a DEVS formalism-based hierarchical discrete-event simulation environment developed by KAIST. In this paper, we are going to show not only applicability of the DEVS formalism to hardware modeling and simulation but also predictability of performance of the load balancer when implemented with FPGA.

• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.49-59
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• 2018

The simulation-based weapon system effectiveness analysis is to support the decision making in the acquisition process of the defense domain. The effectiveness of the weapon system is a complexly influenced indicator from various factors such as environment, doctrine and so on. And the measurement of effectiveness can be defined differently in compliance with major issues in the weapon system. Because of this, the weapon system effectiveness analysis requires the comparative experiment of various alternatives based on the underlying assumption. This paper presents the efficient approach to reconfigure the simulation using the reflection technique. The proposed method contains the recoupling and resetting the simulation entity using DEVS(Discrete EVent System specification) formalism-based dynamic plug-in method. With the proposed method, this paper designs the effectiveness analysis environment that can efficiently handle the various alternatives of the weapon system.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.55-66
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• 2023

In recent years, naval vessels have been developed to fulfill a variety of missions by being equipped with various cutting-edge equipment and ICT technologies. One of the main missions of Korean naval vessels is anti-ballistic missile warfare to defend key units and areas against the growing threat of ballistic missiles. Because the process of detection and interception is too complex and the cost of failure is much high, a lot of preparation is required to effectively conduct anti-ballistic missile warfare. This paper describes the development of a simulation model of anti-ballistic missile warfare with combat systems and equipment to be installed on future naval vessels. In particular, the DEVS formalism providing a modular and hierarchical modeling manner was applied to the simulation model, which can be utilized to efficiently represent various anti-ballistic missile warfare situations. In the simulation results presented, experiments were conducted to analyze the effectiveness of the model for effective detection resource management in anti-ballistic missile warfare. This study is expected to be utilized as a variety of analysis tools necessary to determine the optimal deployment and configuration of combat resources and operational tactics required for effective anti-ballistic missile warfare of ships in the future.