• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.75-87
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• 2007

As the VoIP service quality is getting better and many shortcomings are being overcome, users are getting interested in this service. Also, there are several additional features that provide a convenience to users such as presence service, instant messaging service and so on. But, as there are always two sides of rein, some security issues have users hesitate to make use of it. This paper deals with one of the issues, the VoIP spam problem. We took into account the signal pattern of voice message in spam call and we have constructed voice signal models of normal call, normal call with noise and spam call. Each voice signal case is inserted into our spam decision algorithm which detects the spam calls based on the amount of information in the call signal. We made use of the DEVS-$Java^{TM}$ for our modeling and simulation. The contribution of this work is in suggestion of a way to detect voice spam call signal and testing of the method using modeling and simulation methodology.

• Journal of the Korea Computer Graphics Society
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• v.26 no.5
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• pp.1-13
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• 2020

In this paper, we propose a new method to stable simulation the directional ice shape by coupling of freezing solver and viscous water flow. The proposed ice modeling framework considers viscous fluid flow in the direction of ice growth, which is important in freezing simulation. The water simulation solution uses the method of applying a new viscous technique to the IISPH(Implicit incompressible SPH) simulation, and the ice direction and the glaze effect use the proposed anisotropic freezing solution. The condition in which water particles change state to ice particles is calculated as a function of humidity and new energy with water flow. Humidity approximates a virtual water film on the surface of the object, and fluid flow is incorporated into our anisotropic freezing solution to guide the growth direction of ice. As a result, the results of the glaze and directional freezing simulations are shown stably according to the flow direction of viscous water.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.121-128
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• 2014

This study aims to develop a simulation bed for the mechanical balance of plants of high temperature fuel cells such as molten carbonate fuel cells. For using fuel cells in transportation, the optimization of the balance of plants should be considered. In this study, the dynamic model of a molten carbonate fuel cell and the model's responses to inlet gas composition, pressure, flow rate, and stack temperature were analyzed. On/off simulation was performed for testing the dynamic model's feasibility. The simulation results are in reasonable agreement with the experimental results from published literatures.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.11a
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• pp.109-113
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• 2002

본 연구에서는 서로 다른 형태의 VR 디스플레이 장비인 가상워크벤치와 프로젝션 월을 연동한 이종협업 가상환경을 구축하고 이러한 환경에서 단일 빌딩을 모델링 하는 전과정을 입체적으로 시뮬레이션 할 수 있는 어플리케이션에 대하여 소개한다. 수평 형태의 가상워크벤치 상에서는 건축가와 일반 사용자 혹은 견습 디자이너가 함께 참여하여 빌딩의 형태 및 색상, 재질 등을 인터랙티브하게 변화시키면서 디자인 된 모델을 단계별로 입체 시뮬레이션 할 수 있도록 하였다. 대형의 스크린을 기반으로 하는 수직형 프로젝션 월에서는 디자인 된 빌딩의 입면도를 시뮬레이션하고 빌딩의 외부 및 주변 환경을 네비게이션 할 수 있도록 하여 동일한 모델을 서로 다른 시점에서 관찰하고 의견을 교환하여 이를 모델링에 반영할 수 있도록 하였다.

• Journal of the Korea Society for Simulation
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• v.22 no.2
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• pp.21-31
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• 2013

There is a high demand for the diagnostic medical blood analyzer in the global medical device market. The domestic market is in infant stage, but expected to grow very fast. In this study, we attempt to provide several ways for production improvement in order to secure price competitiveness of domestic medical blood analyzer. For this purpose we identify the problems of current production process using ARENA simulation and suggest several alternatives for productivity improvement.. Five steps of TOC (Theory of Constraints) and ARENA simulation are employed to predict productivity of each alternative and to suggest further improvement.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.51-62
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• 2010

Modeling and Simulation techniques are useful to construct executable battlefields and forces on computers, and have been utilized to analyze effectiveness of weapon systems in the computerized war environment. However, most weapon simulations so far have exhibited low reusability and extensibility, since they have been developed for specific simulation objectives with different structures and simulation engines. In this paper, we identify requirements for defense modeling and simulation activities and propose a simulation engine to support the identified requirements. We define the software architecture of the proposed engine, in a way to efficiently provide usability, component-based reusability, interoperability, and reuse-based development.

• The Magazine of the IEIE
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• v.19 no.1
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• pp.105-114
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• 1992

• The Journal of Society for e-Business Studies
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• v.17 no.1
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• pp.91-110
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• 2012

Recently the effort of retailers improving the efficiency of store operations by using the information technology (IT) is increasing. Among them, the analysis of the shoppers' flow in retail stores is one of the critical tasks since it is an essential part in optimizing store layout and item grouping, and in developing the customized services specialized to shoppers' classification. Agent-Based Modeling and Simulation (ABMS) is one of the most promising methods which support analyzing the shoppers' flow. In this paper, we suggested a shopper's behavior model and developed an agent-based simulator for optimizing the operations of retail stores. In order to model the shoppers' behavior, we analyzed the behavioral characteristics of shoppers based on their shopping lists, suggesting BDI-based agent models of the shoppers' behavior. The shopping agent model were suggested, which has an additional mental state, the shopper's behavioral characteristic, as well as the original mental states of the BDI theory which has beliefs, desires and Intentions. The result of this study can be used in as a preliminary study for modeling and simulation of retail stores congestion and in the end the optimization of item grouping and store layout.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.43-52
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• 2021

In this study, performance modeling and simulation of a gas turbine engine, a constituent module, was performed for the integrated control of the CODOG structure, mechanical propulsion systems. The engine model used MATLAB/Simulink to facilitate integration with the host controller and other components, and was configured to enable input/output settings suitable for the system configuration and purpose. In general, engine manufacturers do not provide performance data for the engine and components. Therefore, as a modeling method for a gas turbine, a CMF method that obtains performance data by scaling the map of components was applied. Using the generated model and simulation program, steady-state and dynamic simulation analysis tests were performed, and reliability within 5% of the maximum error was secured for the final output of power.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.226-228
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• 2009

본 논문에서는 분산전원 시스템을 등가회로를 이용하여 수학적으로 모델링하고, 이를 결합하여 제어 가능한 시스템을 모델링하였다. 시뮬레이션과 실험 결과로부터, 선로 모의실험을 통한 고조파 해석을 IEEE Std 1547.1-2005의 고조파 연계 기준을 통하여 모델링의 적합유무를 판단할 수 있었다. 제시한 계통연계 태양광발전 시스템은 점차적으로 활성화되고 있는 태양광발전 시스템 계통연계 연구에 유용하게 활용될 것이다.