• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.9
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• pp.843-849
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• 2007

Recent progress on software engineering especially in object-oriented design concepts has enabled the development of the simulation models of satellite components in view of reliability and reusability. This paper proposes an useful satellite simulator framework using simulation service and generalized model design. The proposed method is verified by a prototyping in .NET/C# environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.53-61
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• 2002

This paper aims to apply a supply chain modeling and its analysis framework to the supply chain in the port industry, each of which has its own objective. The simulation approach serves two purposes: to model a supply chain network in quantity approach and to evaluate its supply chain performance based on proposed strategies. The simulation model will be applied to quantifying the flow of a supply chain, the involved information and material flow and conducted to simulate the supply chain operations. The model will also be used which strategic and operational policies are the most effective in smoothing the variations in the supply chain.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.55-66
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• 2005

Virtual reality (VR) simulators have been extended to transfer knowledge and education, and demands for exhibition systems for science education and cultural experiences has also increased. Existing VR simulators, which are based on the dynamics equations of motion, cannot easily be adapted to changes in simulation contents. In order to effectively transfer knowledge and maintain interests through educational applications, an experiential system that has multi-sensory effects as well as motion effects is required. In this study, we designed and implemented a motion generation that is tailored to experiential exhibition systems and multi-sensory VR effects. Both the sense of motion which is generated from the movement of the viewpoint of the visual image, and motion effects which are constructed in advance, are applied to motion simulation. Motion effects which occur during interaction between the user and the exhibition system can be easily added. Various sensory cues that are appropriate to the exhibition system are also considered.

• Journal of the Korea Society for Simulation
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• v.11 no.2
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• pp.77-88
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• 2002

Petri nets is a widely used formalism for specification and analysis of concurrent systems which is a subclass of discrete event systems. The DEVS (Discrete Event System Specification) formalism provides a general framework for specification of discrete event systems in a hierarchical, modular form. Often, modeling a discrete event system may employ both Petri Nets and DEVS formalism. In such a case low-level operational logics are modeled by Petri Nets and high-level managements by the DEVS formalism. Analysis of the system requires simulation of the overall system. This paper presents an algorithm for transformation of Petri Nets to DEVS formalism. The transformation enables modelers to simulate an overall system, which consists of DEVS models and Petri Nets models, in a unified DEVS simulation environment such as DEVSim++. An example for such transformation will be given.

• Journal of Korea Technology Innovation Society
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• v.7 no.3
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• pp.533-554
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• 2004

Real option valuation considers the managerial flexibility to make ongoing decisions regarding implementation of investment projects and deployment of real assets. The appeal of the framework is natural given the high degree of uncertainty that firms face in their technology investment decisions. This paper suggests an algorithm for estimating volatility of logarithmic cash flow returns of real asset based on Monte Carlo simulation. This research uses a binomial model to obtain point estimate of real option value with embedded expansion option case and provides also an array of numerical results to show the interval estimation of option value using Monte Carlo simulation.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.4
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• pp.501-506
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• 2013

This research is to develop a simulation framework to gauge the mission effectiveness of the rotorcraft system that will be a part of Korean future combat system. The rotorcraft system comprises of many subsystems that are very time-consuming and tedious to model. Each subsystem and its characteristics have been modeled using component-based modeling techniques, which enhances its reusability. The entire system is then constructed from the individually modeled component, which significantly reduces the modelling time. The mission effectiveness of the rotorcraft system is simulated using the developed models, and the output indicates that the methodology proposed in this study is useful, which will be suitable for the modeling and simulation of Korean future combat system.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.2
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• pp.225-234
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• 2018

A Multibeam Echo Sounder (MBES) is commonly used for rapid seafloor mapping. We herein present a time-domain integrated system simulation technique for MBES development. The Modeling and Simulation (M&S) modules consist of four parts: sensor array signal transmission, propagation and backscattering modeling in the ocean environment, beamforming of the received signals, and image processing. Also, the simulation employs a ray-theory-based algorithm to correct the reconstructed bathymetry, which has errors due to the refraction caused by the vertical sound velocity profile. The developed M&S technique enables design parameter verification and system parameter optimization for MBES. The framework of this technique can also be potentially used to characterize the seabed properties. Finally, typical seafloor images are presented and discussed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.3
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• pp.1-14
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• 2019

Cooperative systems among various unmanned vehicles are widely used in various field and emerging. Unmanned vehicles are able to operate various missions without operator onboard and they are highly stable. Collaborative work of multiple unmanned vehicles is emphasized due to the difficulty of recent missions such as SEAD (Suppression of the Enemy Air Defenses), MUSIC (Manned Unmanned Systems Integration Capability), goldentime in the rescue mission. In this study, ROS and Pixhawk were proposed as a method of construction of a collaboration system and framework for an integrated simulation environment for heterogeneous unmanned vehicles is proposed. Totally 5 unmanned vehicles were set for the simulation for the observation of illegal fishing boats. This paper shows the feasibility of the cooperative system using ROS and Pixhawk through the simulation and the experiment.

• International Journal of Advanced Culture Technology
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• v.10 no.2
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• pp.292-299
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• 2022

In precision agriculture (PA), the differences of the agriculture related parameters such as temperature, humidity, soil moisture among different fields are considered and analyzed to precisely utilize water, pesticides, fertilizer, seeds, etc. in fields. Hence, it becomes possible to increase the profit, reduce waste and maintain quality products. This paper suggests a framework for RFID sensor network in view of PA, especially, associated with Container-grown seedlings(CGS), and presents the analysis and simulation by using Ultra High Frequency (UHF) RFID tag system. The simulation is divided into the transmitter and receiver part using Matlab/Simulink. The architecture of the model is flexible to achieve different modulation and encoding types. Finally, some results of the simulation are presents.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.1
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• pp.154-162
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• 2010

A simulation technique is very useful method to analyze the performance on various engineering area. To automate port systems, we have need of simulation to analyze an effect of assigning and operating devices. Thus we propose simulation methodology to be applied to an analysis, evaluation, planning for port automation. To do this, we have adopted the discrete event system specification based system entity structure / model base framework for modeling and simulation environment. We have performed modeling and simulation on entities of port systems such as container crane, yard tractor, transfer crane, etc. The proposed methodology has an advantage being able to effectively simulate on alternatives of composition and operation strategy for port systems. Some case studies will show the validity of proposed simulation methodology.