• Journal of the Korea Society for Simulation
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• v.6 no.2
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• pp.117-124
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• 1997

A simulation model for the estimation of cutoff connection rate in the asynchronous transfer mode (ATM) switching system under multimedia traffic environments is presented. The simulator is developed by the integration of the AweSim tool with user-written C++ routines that model the internal structures of operational details of the switching system. For the case study, the simulator is applied to the ATM switching system developed by Electronics and Telecommunications Research Institute (ETRI) to compare design alternatives according to the cutoff connection rates.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.3
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• pp.222-230
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• 2004

In this paper, a 3㎾ fuel cell generation system with an active fuel cell simulator has been proposed. The developed fuel cell simulator generates the actual voltage and current output characteristics of the Polymer Electrolyte Membrane Fuel Cell (PEMFC), so that the overall performance and the dynamics of the proposed system could be effectively examined and tested. In This paper, at first, the system configuration and operational principle of the developed fuel cell simulator has been investigated and the design process of the fuel cell generation system is explained in detail. In addition, the validity of the proposed system has been verified lly the informative simulation and experimental result

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.99-106
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• 2010

In the anti-submarine warfare, a search using HMS is used as a basic strategy. The importance of HMS operation strategy is increasing, but it is hard to develop effective anti-submarine search strategy due to reciprocal actions among sea environments, search patterns, sonar operational tactics, anti-submarine search strategy, etc. In this research, a simulator was invented so as to analyze anti-submarine search patterns used when an HMS-carrying ship searches for submarine in various anti-submarine search environments. The simulator reflects various factors that influence anti-submarine search, and with consideration of search patterns of anti-submarine ships as well as evasive movement of submarines, it can simulate various anti-submarine search operations such as a collaborative anti-submarine operation by a single or multiple forces. Also, the simulator will contribute to developing and improving systematic and efficient HMS operational tactics in anti-submarine warfare.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.4
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• pp.543-554
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• 2000

The engineering equations, which have been used in many engineering companies, were employed for the dynamic modelling part in order to develop the naturally circulated boiler simulator. The fuzzy algorithm, which is similar to the algorithm of making decision by the human being, was developed for the boiler simulator controller and its simulated variables were compared with those of classical PID simulations to verify the stability and the effectiveness of fuzzy controller. The simulator is for the naturally circulated boiler and the main components are the furnace, the drum, the super heater, and the economizer. The combustion and thermal radiation dominant equations were used within the furnace and the mass conservation and the energy rate balance equations were employed for the drum part. The heat transfer rates were calculated using the logarithmic mean temperature differences both for the super heater and for the economizer. The simulations are very useful to understand the boiler operations and the engineering design of the main components. The main program was developed under the PC window condition by linking the fuzzy controller to the main boiler program using the Visual C++ language. The various operational conditions such as the abrupt changes of load, the changes of water supply pipes and the diameter of drum were simulated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.6
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• pp.810-816
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• 2012

As wind power has increased steadily, the importance of a condition monitoring system is being emphasized to maximize the availability and reliability of a wind turbine. To develop the advanced algorithms for fault detection and lifespan estimation, a wind turbine simulator is essential for verification of the proposed algorithms before applying them to a condition diagnosis & integrity prognosis system. The developed new-type simulator in this paper includes blades and various sensors as well as a motor, a gearbox and a generator of which the existing simulators generally consist. It also has similarity with a 3MW class wind turbine and can be used to acquire operational data from various operation conditions. This paper presents a design method of control logic for the wind turbine simulator, which gives a wind generation method and similar dynamic characteristics with the 3MW wind turbine. Finally, the proposed control logic is verified through experiments.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.215-217
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• 2008

This paper describes development of hardware simulator for the PMSG wind power system, which was designed considering wind characteristic, blade characteristic and blade inertia compensation. The simulator generates torque and speed signals for a specific wind turbine with respect to given wind speed. This torque and speed signals are scaled down to fit the input of 2kW PMSG. The PMSG-side converter operates to track the maximum power point, and the grid-side inverter controls the active and reactive power supplied to the grid. The operational feasibility was verified by computer simulations with PSCAD/EMTDC, and the implementation feasibility was confirmed through experimental works with a hardware set-up.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1130-1137
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• 2009

This paper describes a scaled model development of PMSG wind power system using wind turbine simulator and matrix converter. The wind turbine simulator, which consists of an induction motor with vector drive, calculates the output torque of a specific wind turbine using simulation software and sends the torque signal to the vector drive after scaling down the calculated value. The operational feasibility of interconnected PMSG system with matrix converter was verified by computer simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was conformed by experimental works with a laboratory scaled-model of wind power system. The simulation and experimental results confirm that matrix converter can be effectively applied for the PMSG wind power system.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.326-333
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• 2003

Railway system is consisted of resources such as rail-line, signalling system, and railcars. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present systematic line capacity analysis model. The proposed model has three main components; TPS(tain performance simulator), PES(parameter evaluation simulator), LCS(line capacity simulator).

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1559-1565
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• 2004

Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(tain performance simulator), PES (parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.58-65
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• 2001

Many changes in the railway environment has directly affected to the railway company. To cope immediately with the influence of environment and to promote productivity, the railway company has to introduce an efficient train operation system and related core technologies. The railway system is composed or large-scale infrastructures ann high-cost trains. Simulation method is one or core technologies and also is efficient tool for planning and analyzing this kind of complex system. The purpose of this research is to develop multi-train traffic simulator considering high-speed train for GyongBu-Line. To achieve this objective, the elements of railway system was analyzed, and as a result, a data structure modeling for the railway system such as rail-Tine infrastructure, rain, timetable and operational route is presented. The developed simulator is composed of three major part : input-module, main-module, and output module. The concept and brief explanation of each module will be treated.