• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.815-817
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• 2003

본 논문은 다품종 소량생산시스템에서 장비 구성 요소들간의 복잡한 활동 및 작업 흐름에 신속하고 유연하게 대처 할 수 있는 프레임워크 구축 방법에 대해서 기술한다. 제안하는 프레임워크의 구조는 OPC와 XML을 이용하여 장비의 행위를 기술하고 제어하는 스크립트를 생성하는 부분과 생성된 스크립트를 시뮬레이션 및 실제 동작시키는 부분으로 구성된다. 이 프레임워크는 표준화와 개방화 추세에 따라 기존 시스템과 쉽게 결합하고 통합할 수 있는 구조를 갖는다. 또한 장비의 행위를 미리 구성하고 시뮬레이션을 통하여 장비 개발의 질을 향상시키고 발생 가능한 문제를 미리 예측할 수 있으므로 장비 제어 시스템의 개발 및 유지보수에 대한 비용을 현저히 줄일 수 있다.

• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.11-18
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• 2007

Recently, as weapon systems have been more diverse and complicated, the factors of risk increase in development. Consequently, demanding reduction of acquired costs and period increase. Under the acquisition environment, more efficiently to develop weapon system, the necessity of application of defense M&S from requirement phase is on the rise. As the importance of M&S is stressed under distributed environment, so the standard of M&S(HLA, SEDRIS, etc.) and the system engineering process, namely FEDEP(Federation Development & Execution Process) have been developed. In this paper using the 5 phase expression, we constructed underwater engagement simulation(UNES) that prototype to develop naval weapon system test bed which take up integrated architecture in HLA. we developed simulators according to FEDEP for expandability and described process applying FEDEP fur UNES development.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.491-500
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• 2003

The need for network security is being increasing due to the development of information communication and internet technology, In this paper, firewall models, operating system models and other network component models are constructed. Each model Is defined by basic or compound model using MODSIM III. In this simulation environment with representative attacks, the following attacks are generated, SYN flooding and Smurf attack as an attack type of denial of service. The simulation is performed with the models that exploited various security policies against these attacks. In addition, the results of the simulation show that the analysis of security performance according to various security policies, and the analysis of correlation between availability and confidentiality according to security empowerment.

• Journal of The Korean Association of Information Education
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• v.15 no.4
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• pp.533-542
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• 2011

In this paper, we have selected traveling algorithms of Line-Tracer as the focused learning elements with the PBL-based programming instruction method. Line-Tracer traveling algorithm programming has been simulated using the Scratch EPL. Development of robot web courseware such as Line-Tracer can create an effective educational environment and also provide solutions for lack of environmental conditions, such as time or spatial factor restrictions and excessive expense issues; these are major obstacles to developing robot programming education. Finally, we analyzed the effects on growth of student's logical thinking and problem solving abilities by demonstrating the Scratch application courseware to the field of elementary education.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.927-933
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• 2014

Ship Power Management System(SPMS) based on Communication Network(CN) is one of the most significant factor for a safe voyage. Therefore, most of the vessels are using greater capacity generator than necessary to prevent pulsating load for safety purposes. However, It provokes low-load damage and reduces generator efficiency that using large capacity generator. Accordingly, in this paper propose hybrid power system for prevent damage of pulse load. Simulation using NI's LabVIEW was conducted for the design of the power system based on actual navigation data of the ship. Also, propose applying methods for hybrid power system in connection with the auxiliary power system for safe navigation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.383-384
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• 2020

다중 이용시설, 학교, 주택 등 사람이 많이 이용하는 곳은 화재 발생 빈도가 높을 뿐만 아니라 대피하기가 어렵고, 기존의 비상등 표시 방법, 일회성 대피 안내 등으로 인해 화재 상황의 다양한 변수에 효과적으로 대처하기 어렵다. 본 논문에서는 디지털 트윈(Digital Twin) 기술을 기반으로 다양한 센서를 통해 인식된 화재 요소를 반영한 화재 대응 및 피난 시뮬레이션(Fire Dynamic Simulator & Pathfinder)을 통해 안전한 대피 경로를 도출하여 안내하는 시스템을 설계한다. 제시하는 방법은 화재 상황에 능동적으로 대처하기 위해 실시간 인원변동 및 변화하는 화재변수에 대비 할 수 있으며, 상황에 따른 적극적인 대피 훈련과 실제 상황에서의 긴급한 상황에서의 대피경로 도출과 안내에 활용할 수 있다.

• Journal of the Korea Society for Simulation
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• v.29 no.2
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• pp.11-20
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• 2020

As the manufacturing environment becomes more complex, traditional simulation models alone are having a lot of difficulties in reflecting real-time manufacturing situations. Although the Digital Twin concept is actively discussed as an alternative to overcome theses issues, many studies are being carried out only in the product design phase. This research presents a Digital Twin-based manufacturing environment framework for applying the Digital Twin concept to the manufacturing process. Twin model that is operated in virtual space, physical system and databases describing the actual manufacturing environment, are proposed as detailed components that make up the framework. To check the applicability of proposed framework, a simple Digital Twin-based manufacturing system was simulated in a conveyor system using Arena software and Excel VBA. Experiment results have shown that the twin model is transmitted real time data from the physical system via DB and were operating in the same time unit. The Excel VBA fitted parameters defined by cycle time based on historical data that real-time and training data are being accumulated together. This study proposes operating method of digital twin model through the simple experiment examples. The results lead to the applicability of Digital twin model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1670-1679
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• 2011

In the area of wireless sensor networks, sensor coverage and network connectivity problems are caused by a limited detection range and the communication distance of the nodes. To solve the coverage and connectivity problems, many studies are suggested, but most research is restricted to apply into the real environment because they didn't consider various environmental factors on wireless sensor network deployment. So in this paper, we propose a node deployment strategy considering environmental factors and the number of nodes in surveillance and reconnaissance sensor networks(SRSN). The proposed node deployment method divides the installation of the surveillance and reconnaissance sensor networks system into four steps such as identification of influences factors for node placement through IPB process, sensor node deployment based on sensing range, selection of monitoring site, and relay node deployment based on RF communication range. And it deploys the sensor nodes and relay nodes considered the features of the surveillance and reconnaissance sensor network system and environmental factors. The result of simulation indicates that the proposed node deployment method improves sensor coverage and network connectivity.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1081-1088
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• 2021

The modern wireless communication system employes the beamforming technique based on a massive array antenna with a number of elements, for supporting the smooth communication services. A reliable beamforming technology requires the Angle-of-Arrival(: AOA) information for the signal incident to the receiving antenna, which is generally estimated by the high-resolution AOA estimation algorithm such as Multiple Signal Classification(: MUSIC). Although the MUSIC algorithm has the excellent estimation performance, it is difficult to estimate AOA in real time for the massive array antenna due to the extremely high computational complexity. In order to enhance this problem, in this paper, we propose the cascade AOA estimation algorithm based on a Flexible Massive Concentric Circular Array(: FMCCA) antenna with the On/Off function for antenna elements. The proposed cascade algorithm consists of the CAPON algorithm using some elements among entire antenna elements and the Beamspace MUSIC algorithm using entire elements. We provide computer simulation results for various scenarios to demonstrate the AOA estimation performance of the proposed approach.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1489-1495
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• 2012

In this study, we perform the structural analysis of a floating offshore wind turbine tower by considering the dynamic response of the floating platform. A multibody system consisting of three blades, a hub, a nacelle, the platform, and the tower is used to model the floating wind turbine. The blades and the tower are modeled as flexible bodies using three-dimensional beam elements. The aerodynamic force on the blades is calculated by the Blade Element Momentum (BEM) theory with hub rotation. The hydrostatic, hydrodynamic, and mooring forces are considered for the platform. The structural dynamic responses of the tower are simulated by numerically solving the equations of motion. From the simulation results, the time history of the internal forces at the nodes, such as the bending moment and stress, are obtained. In conclusion, the internal forces are compared with those obtained from static analysis to assess the effects of wave loads on the structural stability of the tower.