• International Journal of CAD/CAM
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• 제6권1호
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• pp.3-8
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• 2006

The application of three-dimensional (3-D) CAD has been popularized for design and production and digital manufacturing has been spreading in many industrial fields. By simulation of the production process using 3-D digital models, which are the core of CIM (Computer Integrated Manufacturing) system, the efficiency and safety of production are improved at each stage of work, and optimization of manufacturing can be achieved. This paper firstly describes the concept of "simulation based production" in shipbuilding and also digital manufacturing; the 3-D CAD system is indispensable for effective simulation because ship structure is three dimensionally complex. By simulation, "computer optimized manufacturing" can be possible. The most effective fields of simulation in shipbuilding are in jobs where many parties have to cooperate, while existing two-dimensional drawings are hardly observed the whole structures due to interference between structures or equipment of complex shape. In this paper some examples of the successful application in IHIMU (IHI Marine United Inc.) are shown: assembly of a pipe unit, erection of a complex hull block, carriage of equipment, installation of a propeller, and access in an engine room.

• 한국시뮬레이션학회논문지
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• 제12권4호
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• pp.25-40
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• 2003

With the growing usage of the networks, the world-wide Internet has become the main means to exchange data and carry out transactions. It has also become the main means to attack hosts. To solve the security problems which occur in the network such as Internet, we import software products of network security elements like an IDS (Intrusion Detection System) and a firewall. In this paper, we have designed and constructed the general simulation environment of network security model composed of multiple IDSes and a firewall which coordinate by CNP (Contract Net Protocol) for the effective detection of the intrusion. The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. Command console in the CNP is a manager who controls the execution of agents or a contractee, who performs intrusion detection. In the network security model, each model of simulation environment is hierarchically designed by DEVS(Discrete Event system Specification) formalism. The purpose of this simulation is that the application of rete pattern-matching algorithm speeds up the inference cycle phases of the intrusion detection expert system and we evaluate the characteristics and performance of CNP architecture with rete pattern-matching algorithm.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권1호
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• pp.37-47
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• 2018

Dynamic simulation is critical for electrical ship studies as it obtains the necessary information to capture and characterize system performance over the range of system operations and dynamic events such as disturbances or contingencies. However, modeling and simulation of the interactive electrical and mechanical dynamics involves setting up and solving system equations in time-domain that is typically time consuming and computationally expensive. Accurate assessment of system dynamic behaviors of interest without excessive computational overhead has become a serious concern and challenge for practical application of electrical ship design, analysis, optimization and control. This paper aims to develop a systematic approach to classify the sophisticated dynamic phenomenon encountered in electrical ship modeling and simulation practices based on the design intention and the time scale of interest. Then a novel, comprehensive, coherent, and end-to-end mathematical modeling and simulation approach has been developed for the latest Medium Voltage Direct Current (MVDC) Shipboard Power System (SPS) with the objective to effectively and efficiently capture the system behavior for ship-wide system-level studies. The accuracy and computation efficiency of the proposed approach has been evaluated and validated within the time frame of interest in the cast studies. The significance and the potential application of the proposed modeling and simulation approach are also discussed.

• 대한원격탐사학회지
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• 제24권5호
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• pp.497-506
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• 2008

The needs for digital models of real environment such as 3D terrain or cyber city model are increasing. Most of applications related with modeling and simulation require virtual environment constructed from geospatial information of real world in order to guarantee reliability and accuracy of the simulation. The most fundamental data for building virtual environment, terrain elevation and orthogonal imagery is acquired from optical sensor of satellite or airplane. Providing interoperable and reusable digital model is important to promote practical application of high-resolution satellite imagery. This paper presents the new research regarding representation of geospatial information, especially for 3D shape and appearance of virtual terrain. and describe framework for constructing real-time 3D model of large terrain based on high-resolution satellite imagery. It provides infrastructure of 3D simulation with geographical context. Web architecture, XML language and open protocols to build a standard based 3D terrain are presented. Details of standard-based approach for providing infrastructure of real-time 3D simulation using high-resolution satellite imagery are also presented. This work would facilitate interchange and interoperability across diverse systems and be usable by governments, industry scientists and general public.

• 한국컴퓨터정보학회논문지
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• 제13권6호
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• pp.25-31
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• 2008

웹은 1990년 Berners Lee가 웹 서버와 브라우져를 소개한 이후 우리 생활에 필수 불가결한 요소로 발전되고 있다. 웹의 성능은 사용자와 관리자의 관점이 조금 다를 수 있다. 즉 사용자는 빠른 응답시간에 관심이 있고 관리자는 응답시간뿐만 아니라 처리율과 같은 시스템 메트릭에도 관심이 있다. 웹 애플리케이션의 성능은 인터넷의 전체적인 운영환경을 구성하고 있는 여리가지의 요소에 관련되어 있으므로 예측하기가 쉽지 않다. 본 논문에서는 Buch and Pentkowski [1]가 측정한 성능 데이터와 Gunther [2]가 제시한 분석적 모델을 기초로 대략적 시뮬레이션 모델을 제시하였다. 시뮬레이션 모델은 특히 관심이 있는 응답시간과 처리율을 중심으로 구성하였으며 큐 길이 등에 대한 결과도 추출하였다. 본 시뮬레이션 모델의 결과는 측정된 데이터와 거의 일치하였고 이를 이용하여 성능을 예측할 수 있음을 보였다.

• 한국시뮬레이션학회논문지
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• 제19권1호
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• pp.91-101
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• 2010

전투관리언어인 BML은 미군에서 가상 부대 및 실제 부대를 지휘 및 통제하기 제공하기 위한 명확한 언어라고 정의할 수 있다. BML은 C2 체계와 M&S를 연결하기 위해 미국과 NATO에서 개발되었다. BML이 개발된 목적은 전장정보를 통해 상황인식을 제공하고, C2 체계와 M&S간 상호운용을 위한 해법을 제시하는 것이라고 할 수 있다. 본 연구는 육군에서 시작하여 다국적국으로 구성된 환경으로 확장되고 있는 미국의 BML 개발과정에 대해서 설명하고, 한국군에서 C4I체계와 M&S간 상호운용을 위한 BML 적용 방안에 대해서 제안한다. 최근, 미국에서는 BML을 연합국으로 구성된 환경에서 적용하여 긍정적인 결과를 얻었는데, 이는 C2 체계와 M&S간 상호운용에 대한 가능성을 보여주었다. 마지막으로, 본 연구는 BML을 한국군에 적용하기 위한 방안으로 한국군 합동지휘통제체계를 중심으로 제안하였다. 이는 향후 한국군에서 BML 적용시 밑그림을 제공 할 것이라고 판단된다.

• 한국시뮬레이션학회논문지
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• 제6권2호
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• pp.59-69
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• 1997

This paper proposes a simulation method of train control system to increase railroad transportation capacity in the Seoul Subway. Comparing with the conventional fixed block system, a new train operation method of "moving block system" shows a more capability of same railroad. A graphic simulation program is developed for application of moving block system to Seoul subway train control system. The result of the simulation program shows a shorten headway i.e. a more dense operation of trains and a higher efficiency of railroad with the suggested moving block system.

• 한국시뮬레이션학회논문지
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• 제2권1호
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• pp.125-133
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• 1993

A statistical method is described for estimation of the unknown constants in a theory using both of the computer simulation data and the real experimental data, The best linear unbiased predictor based on a spatial linear model is fitted from the computer simulation data alone. Then nonlinear least squares estimation method is applied to the real experimental data using the fitted prediction model as if it were the true simulation model. An application to the computational nuclear fusion devices is presented, where the nonlinear least squares estimates of four transport coefficients of the theoretical nuclear fusion model are obtained.

• 한국정보통신학회논문지
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• 제18권5호
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• pp.1128-1134
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• 2014

컴퓨팅 기술의 발달과 네트워크의 확산으로 보다 쉽게 실세계의 다양한 현상들을 수치적으로 분석할 수 있는 웹기반 시뮬레이션 서비스가 활발히 이용되고 있다. 그러나 대부분의 서비스에서 시뮬레이션 수행 내역이 공유/공개되지 않아 사용자들이 같은 실험을 반복해서 수행해야하고 데이터나 정보를 공유하기 어렵다. 이 논문에서는 첨단 사이언스 교육 허브 (EDISON, EDucation-research Integration Simulation On the Net)의 열유체 분야 시뮬레이션 서비스를 중심으로, 기존에 수행된 시뮬레이션 수행내역을 공개할 수 있는 이력출처 데이터 공유 서비스를 설계한다. 공유 서비스를 위해 EDISON_열유체 시뮬레이션 수행 과정을 "문제 ${\rightarrow}$ 계획, 설계 ${\rightarrow}$ Mesh ${\rightarrow}$ 시뮬레이션 수행 ${\rightarrow}$시뮬레이션 결과분석 ${\rightarrow}$ 보고서"로 정의하고 이에 맞게 기존의 시뮬레이션 수행 정보를 저장한다. 사용자는 이력출처 스토어의 검색/공유 API를 통해 시뮬레이션 수행 내역을 검색하여, 시뮬레이션을 통해 어떤 문제가 어떻게 해결되는지를 이해할 수 있다. 또한 동일한 시뮬레이션을 수행하는 시간과 계산자원의 낭비를 줄일 수 있다.

• Structural Engineering and Mechanics
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• 제30권3호
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• pp.331-350
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• 2008

A framework for multi-platform analytical and multi-component hybrid (testing-analysis) simulations is described in this paper and illustrated with several application examples. The framework allows the integration of various analytical platforms and geographically distributed experimental facilities into a comprehensive pseudo-dynamic hybrid simulation. The object-oriented architecture of the framework enables easy inclusion of new analysis platforms or experimental models, and the addition of a multitude of auxiliary components, such as data acquisition and camera control. Four application examples are given, namely; (i) multi-platform analysis of a bridge with soil and structural models, (ii) multiplatform, multi-resolution analysis of a high-rise building, (iii) three-site small scale frame hybrid simulation, and (iv) three-site large scale bridge hybrid simulation. These simulations serve as illustrative examples of collaborative research among geographically distributed researchers employing different analysis platforms and testing equipment. The versatility of the framework, ease of including additional modules and the wide application potential demonstrated in the paper provide a rich research environment for structural and geotechnical engineering.