• Journal of the Korea Institute of Information and Communication Engineering
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• 제3권4호
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• pp.755-764
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• 1999

In this study, the system level network simulation is considered with adaptive array antenna in CDMA mobile communication system. A network simulation framework is implemented based on IS-95A/B system to consider dynamic handoff, system level network behavior, and deploying strategy into the overall CDMA mobile communication network under adaptive array algorithm. Its simulation model, such as vector channel model, adaptive beam forming antenna model, handoff model, and power control model, are described in detail with simulation block. In order to maximize SINR of received signal at antenna, maximin algorithm is particularly considered, and it is computed at each simulation snap shot with SINR based power control and handoff algorithm. Graphic user interface in this system level network simulator is also implemented to define the simulation environments and to represent simulation results on real mapping system. This paper also shows some features of simulation framework and simulation results.

• Journal of Institute of Control, Robotics and Systems
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• 제14권2호
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• pp.111-117
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• 2008

This paper presents a new continuation-based quasi-steady-state(CQSS) time-domain simulation algorithm incorporating a multiplicative aggregated load model for power systems. The authors' previous paper introduced a CQSS algorithm, which has the robust convergent characteristic near the singularity point due to the application of a continuation method. The previous CQSS algorithm implemented the load restoration in power systems using the exponent-based load recovery model that is derived from the additive dynamic load model. However, the reformulated exponent-based model causes the inappropriate variation of short-term load characteristics when switching actions occur, during time-domain simulation. This paper depicts how to incorporate a multiplicative load restoration model, which does not have the problem of deforming short-term load characteristics, into the time simulation algorithm, and shows an illustrative example with a 39-bus test system.

• Journal of the Korea Society for Simulation
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• 제16권4호
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• pp.23-31
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• 2007

Anti-Air Warfare(AAW) functionality of the naval combat system is the key functionality to ensure the ship's survivability. We have applied a novel method using model-based-simulation to analyze and design AAW functionality of the Patrol Killer Experimemnt Combat System. In this approach, an AAW functional model is described with the FSM(Finite State Machine) and directly executed for the AAW simulation. After prototyping using model based simulation, Hardware In Loop Simulation(HILS) is conducted as the AAW functionality is interfaced with the other ones of the combat system for completing the integration of the system components. This incremental and iterative development approach based on the model based simulation can minimize the development risks and costs caused by the system complexity for military system, bringing out the merit of the rapid prototyping.

• Journal of Korean Institute of Industrial Engineers
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• 제41권6호
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• pp.588-598
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• 2015

In this paper, a simulation model for assessing the impact of alternative field service engineer replenishment policies is introduced. The end-to-end supply chain simulation model is created using a discrete-event and agent-based simulation model, which enables accurate description of key individual entities in the investigated supply chain, such as field service engineers. Once the model is validated with the historical data, it is used to assess the impacts of field service engineer replenishment policies for a major printing equipment manufacturing firm.In the case study, newly proposed replenishment policies for post-sale distribution supply chain are assessed for the level of service improvement to end customers.

• Journal of the Korea Society for Simulation
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• 제9권4호
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• pp.41-50
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• 2000

We have many simulation constraints to meet as a modeled system becomes large and complex. Real-time simulations are the examples in that they are constrained by certain non-function constraints (e.g., timing constraints). In this paper, an enhanced hierarchical modeling methodology is proposed to efficiently deal with constraint-simulations. The proposed modeling method enhances hierarchical modeling methods to provide multi-resolution model. A simulation model is composed by determining the optimal level of abstraction that is guaranteed to meet the given simulation constraints. Four modeling activities are defined in the proposed method: 1) Perform the logical architectural design activity to produce a multi-resolution model, 2) Organize abstraction information of the multi-resolution model with AT (Abstraction Tree) structure, 3) Formulate the given constraints based on U (Integer Programming) approach and embrace the constraints to AT, and 4) Compose a model based on the determined level of abstraction with which the multi-resolution model can satisfy all given simulation constraints. By systematically handling simulation constraints while minimizing the modeler's interventions, we provide an efficient modeling environment for constraint-simulations.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2006년도 춘계학술대회
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• pp.87-109
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• 2006

The purpose of this paper is to examine the present performance evaluation methods and to make Monte Carlo Simulation Model for the IT-based Government innovation project. It is suggested the proper ways in applying of Monte Carlo Simulation Model by integration of present evaluation methods. It develops the theoretical framework for this paper, examining the existing literature on proposing an approach to the key concepts of the economic impact analysis methods. It examines the actual conditions of performance evaluation focusing on the It-based Government Innovation project. It considers how the simulation model is applied to the performance management in the public innovation project focusing on the framework, process and procedure of performance management.

• Journal of Industrial Technology
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• 제27권A호
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• pp.149-155
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• 2007

The counter emf(electromotive forces) of a permanent magnet multi-phase brushless motor is generally a non-sinusoidal wave or a non-ideal trapezoid. So, conventional modeling using a sinusoidal wave or an ideal trapezoid counter emf can result in errors. In order to reduce modeling errors for simulation and analysis the properties of a multi-phase brushless AC motor, this paper proposes a phase variable model that is a mixed modeling technique using both Finite Element Analysis(FEA) based circuits and motor voltage equations. The phase model parameters including the counter emf voltage waveform are obtained by using of FEA, and the mixed modeling technique based on circuits and equations is used to implement a simulation model for multi-phase brushless AC motors with any counter emf voltage waveforms. Adequacy of the proposed model is established from the simulation and experimental results for a seven-phase brushless motor.

• International conference on construction engineering and project management
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.32-41
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• 2017

Accidents on offshore oil and gas platforms (OOGPs) usually cause serious fatalities and financial losses considering demanding environment platforms locate and complex topsides structure platforms own. Evacuation planning on platforms is usually challenging. The computational tool is a good choice to plan evacuation by emergency simulation. However, the complex structure of platforms and varied evacuation behaviors usually weaken the advantages of computational simulation. Therefore, this study developed a simulation model for OOGPs to evaluate different evacuation plans to improve evacuation performance by integrating building information modeling (BIM) and agent-based model (ABM). The developed model consists of four parts: evacuation model input, simulation environment modeling, agent definition, and simulation and comparison. Necessary platform information is extracted from BIM and then used to model simulation environment by integrating matrix model and network model. During agent definition, in addition to basic characteristics, environment sensing and dynamic escape path planning functions are also developed to improve simulation performance. An example OOGP BIM topsides with different emergent scenarios is used to illustrate the developed model. The results showed that the developed model can well simulate evacuation on OOGPs and improve evacuation performance. The developed model was also suggested to be applied to other industries such as the architecture, engineering, and construction industry.

• Proceedings of the Korea Society for Simulation Conference
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• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
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• pp.106-110
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• 1998

Some successful scheduling systems are based on simulation technique. However, they are relatively expensive. A cost-effective solution is to apply general-purpose simulation software to the scheduling system. This paper is concerned with developing a simulation model for MPS(Master Production Schedule) evaluation system. The target system of the model is PC production system. AIM (Analyzer for Improving Manufacturing system), a well-known manufacturing oriented simulation software, is used for modeling tool. Eventually, the model can be included into an MPS evaluation system as simulation module and a scheduler can use the system to verify the MPS in advance.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• 제14권1호
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• pp.16-21
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• 2018

This work aims to develop a platform to investigate the effect of operation schedules on the building energy consumption and to derive a simulation model based optimal start and stop daily strategy. An open-source building energy simulation tool DOE2 is used for the engine, and the developed simulation model is validated using ASHRAE guideline 14. The effect of late-start/early-stop operation of HVAC system on the daily building energy consumption was analyzed using the developed simulation model. It was found that about 10% of energy consumption cut was possible using the control strategy for an hour of advance of the stop operation, and about 3% per an hour of delay of the start operation.