• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.6
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• pp.87-95
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• 2004

In this paper, an efficient method for modeling a dual-rotor type wind turbine generator system and simulation results are presented. The wind turbine is treated as a collection of several rigid bodies, each of which represents, respectively, main and auxiliary rotor blades, high/low speed shafts, generator, and gear system. Simulation software WINSIM is developed to implement the proposed modeling method and is used to investigate the transient and steady-state performance of the wind turbine system.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.537-547
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• 2014

In this paper, the ALT (ALTernative) board and a NetLogo extension module are developed for the active participatory simulation (APS) learning. Through the participatory simulation with HubNet each student can attend the experiment as one of clients. Only one HubNet server, however, is able to use an external device so that the bifocal modeling based learning with multiple users is impossible. In order to overcome the drawback, and enable clients participate into the experiment and collect the experimental data and the measured data, an ATmega 32 based board and its firmware are developed. In addition, Java extension module based on TCP/IP socket interfaces is developed to exchange the data with HubNet server. Finally, we show some NetLogo program examples to use the developed hardware and software for APS and seek the way to use them for science education.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.541-544
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• 2005

This study presents the integrated modeling approach to simulate the proton exchange membrane (PEM) fuel cell system for vehicle application. The fuel cell system consisting of stack and balance of plant (BOP) was simulated with MATLAB/Simulink environment to estimate the maximum system power and investigate the effect of BOP component sizing on system performance and efficiency. The PEM fuel cell stack model was established by using a semi-empirical modeling. To maximize the net efficiency of fuel cel1 system, multi-variable optimization code was adopted. Using this method the optimized operating values were obtained according to various system net power levels. The fuel cell model established was co-linked to AVL CRUISE, a vehicle simulation package. Through the vehicle simulation software, the fuel economy of fuel cell powered electric vehicle for two types of driving cycles was presented and compared. It is expected that this study tan be effectively employed in the basic BOP component sizing and in establishing system operation map with respect to net power level of fuel cell system.

• New & Renewable Energy
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• v.1 no.4 s.4
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• pp.43-48
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• 2005

This study presents the integrated modeling approach to simulate the proton exchange membrane [PEM] fuel cell system for vehicle application. The fuel cell system consisting of stack and balance of plant (BOP) was simulated with MATLAB/Simulink environment to estimate the maximum system power and investigate the effect of BOP component sizing on system performance and efficiency. The PEM fuel cell stack model was established by using a semi-empirical modeling. To maximize the net efficiency of fuel cell system, multi-variable optimization code was adopted. Using this method, the optimized operating values were obtained according to various system net power levels. The fuel cell model established was co-linked to AVL CRUISE, a vehicle simulation package. Through the vehicle simulation software, the fuel economy of fuel cell powered electric vehicle for two types of driving cycles was presented and compared. It is expected that this study can be effectively employed in the basic BOP component sizing and in establishing system operation map with respect to net power level of fuel cell system.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.153-158
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• 2008

The technology of Software Defined Radio (SDR) is a possible solution to interwork flexibly between various wireless transport protocols. Ubiquitous network, like u-health service network, includes sensor devices or nodes which do not facilitate all the same transport protocols to access network. As such this may be in such unreachable situations as poverty of all required AP (Access Point)’s, faults or contention in a path of particular protocol communication, etc. This paper presents research results of modeling and simulation to analyze transport performance of multi-protocol ubiquitous network which includes SDR-based interwork nodes and congestion-controlled AP’s. Focusing mainly on dynamics of overall transport performance rather than protocol execution procedures, this paper employs the Zeigler’s DEVS (Discrete Event Systems Specification) methodology and DEVSim++simulation environment to experiment.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.217-223
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• 2023

In this study, we compared the VacCAD and VacTran, commercial vacuum simulators, to investigate the simulation applicability and efficiency as vacuum simulation software. It was verified on reliability and simplicity of simulation modelling, and characteristics of the pump combinations, pumping down curves, and employed vacuum materials. First, usability of simulation schematics was estimated through the modeling tools and the overall simulation characteristics of each simulator were compared to evaluate the applicability in practice. Simulation reliability of each simulator was also probed by comparing the pumping performance characteristics of commercial high vacuum system models. In addition, the degree of tolerances on both simulators was also evaluated through pumping down analysis considering outgassing effect due to chamber material variations. The higher effectiveness and expediency of VacCAD than VacTran has been presented, and it was also expected that the utilization of VacTan in vacuum applications to be increased due to the higher availability of modelling variations.

• Computers and Concrete
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• v.18 no.1
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• pp.99-112
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• 2016

Since the preservation of monuments is very important to human societies, different methods are required to preserve historic structures. In this paper, 3D model of arch stone bridge at Pont Saint Martin, Aosta, Italy, was simulated by 1660 integrated separate stones using ABAQUS$^{(R)}$ software to investigate the seismic susceptibility of the bridge. The main objective of this research was to study a method of preservation of the historical stone bridge against possible earthquakes using FRP techniques. The nonlinear behavior model of materials used theory of plasticity based on Drucker-Prager yield criterion. Then, contact behavior between the block and mortar was modeled. Also, Seismosignal software was used to collect data related to 1976 Friuli Earthquake Italy, which constitutes a real seismic loading. The results show that, retrofitting of the arch stone bridge using FRP techniques decreased displacement of stones of spandrel walls, which prevents the collapse of stones.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.395-402
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• 2005

This paper deals with modeling and computer simulation of a full multibody vehicle model for a driving simulator. The multibody vehicle model is based on the recursive formulation and a corresponding simulation code is generated automatically from AUTOCODE, which is a symbolic computation package developed by the authors using MAPLE. The paper describes a procedure for automatically generating a highly efficient simulation code for the full vehicle model, while incorporating realistically modeled components. The following issues have been accounted for in the procedure, including software design for representing a mechanical system in symbolic form as a set of computer data objects, a multibody formulation for systems with various types of connections between bodies, automatic manipulation of symbolic expressions in the multibody formulation, interface design for allowing users to describe unconventional force-and torque-producing components, and a method for accommodating external computer subroutines that may have already been developed. The effectiveness and efficiency of the proposed method have been demonstrated by the simulation code developed and implemented for driving simulation.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.377-382
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• 2010

In lunar explorer development program, computer simulator is necessary to provide virtual environments that vehicle confronts in lunar transfer, orbit, and landing missions, and to analyze dynamic behavior of the spacecraft under these environments. Objective of simulation differs depending on its application in spacecraft development cycle. Scope of use cases considered in this paper includes simulation of software based, processor and/or hardware in the loop, and support of ground-based flight test of developed vehicle. These use cases represent early phase in development cycle but reusability of modeling results in the next design phase is considered in defining requirements. A simulator architecture in which simulator platform is located in the middle and modules for modeling, analyzing, and three dimensional visualizing are connected to that platform is suggested. Baseline concepts and requirements for simulator development are described. Result of trade study for selecting simulation platform and approaches of defining other simulator components are summarized. Finally, characters of lunar elevation map data which is necessary for lunar terrain generation is described.

• Journal of Navigation and Port Research
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• v.35 no.6
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• pp.489-494
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• 2011

Present study introduces an implementation of product data management (PDM) that can be applied to the design of ship propulsion system. The PDM system is developed based on both object oriented software development environment and Open Scene Graph (OSG) library while the system architecture is modeled by the unified modeling language (UML). Suggested PDM system also integrates the modeling & simulation components required to estimate the performance of ship propulsion system as the product information is represented based on the 3-dimensional digital mock-up (DMU). Finally, functions of the implemented PDM system that is integrated with the M&S softwares are illustrated in order to suggest a practical guidance for the efficient design of ship propulsion system.