• Korean Journal of Computational Design and Engineering
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• v.20 no.3
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• pp.221-229
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• 2015

M&S (Modeling & Simulation) based design is widely accepted for the development of the future weapon system with better performance in a cheaper and faster way. Integrated simulation environment (ISE) is needed for the M&S based design. On the ISE, system engineers can not only verify design options but also validate system requirements. In this paper, we propose architectural models of the integrated simulation environment (ISE) which incorporates mission effectiveness M&S (Modeling & Simulation), system performance M&S, the optimization model of integrated performances, digital mockup and virtual prototype. The ISE architectural models may be used to implement the ISE for the development of the future unmanned ground combat vehicle.

• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.81-90
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• 2012

Presented in this paper is a study for construction of a simulation system for the engagement of ground weapon systems. This paper proposes architecture for the simulation system based on agent simulation design methodology. Every entity of the proposed architecture is developed by assembling modularized agent components, and it enhances the reusability and composability of the entity. Consequently, time, costs, and efforts that are required to develop a new simulation system is able to be reduced by the enhancement. In the case of ground engagement simulation, it is very important to reflect environmental effects. Synthetic battlefield of the proposed architecture has environmental data of the battlefield and interacts with entities in the simulation system. The proposed architecture based simulation system can build swiftly various simulation models by the objectives and derive reasonable results from behaviors of entities that include environmental effects. This paper contains the construction of an example system based on the proposed architecture to verify the advantages of the architecture.

• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.6
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• pp.233-240
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• 2021

The stochastic method is applied to simulate strong ground motions at seismic stations of seven metropolises in South Korea, creating an earthquake scenario based on the causative fault of the 2016 Gyeongju earthquake. Input parameters are established according to what has been revealed so far for the causative fault of the Gyeongju earthquake, while the ratio of differences in response spectra between observed and simulated strong ground motions is assumed to be an adjustment factor. The calculations confirm the applicability and reproducibility of strong ground motion simulations based on the relatively small bias in response spectra between observed and simulated strong ground motions. Based on this result, strong ground motions by a scenario earthquake on the causative fault of the Gyeongju earthquake with moment magnitude 6.5 are simulated, assuming that the ratios of its fault length to width are 2:1, 3:1, and 4:1. The results are similar to those of the empirical Green's function method. Although actual site response factors of seismic stations should be supplemented later, the simulated strong ground motions can be used as input data for developing ground motion prediction equations and input data for calculating the design response spectra of major facilities in South Korea.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.16 no.1
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• pp.17-25
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• 2020

Ground-coupled heat pump (GCHP) systems have become an efficient alternative to conventional cooling and heating methods due to their higher energy using efficiency. Although some experimental and simulation works related to performance analysis of GCHP systems for commercial buildings have been done, relatively little has been reported on the performance evaluation of GCHP systems for school buildings. The purpose of this simulation study is to evaluate the performance of a hypothetical GCHP system for a school building in Seoul. We collected various data of building specifications and construction materials for the building and then modeled to calculate hourly building loads with SketchuUp and TRNSYS V17. In addition, we used GLD (Ground Loop Design) V2016, a GCHP system design and simulation software, to design the GCHP system for the building and to simulate temperature of circulating water in ground heat exchanger. The variation of entering source temperature (EST) into the system was calculated with different prediction time and then each result was compared. For 20 years of prediction time, EST for baseline design (Case A) based on the hourly simulation results were outranged from the design criteria.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.195-202
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• 2002

By using modeling and simulation. today's design engineers are simultaneously reducing time to market and decreasing the cost of development, while increasing the quality and reliability of their products. A driving simulator is the best example of this method and allows virtual designs of control systems, electronic systems, mechanical systems and hydraulic system of a vehicle to be evaluated before costly prototyping. The objective of this Paper is to develop the virtual Proving: ground using a driving simulator and to show its capabilities of an automotive system development tool. For this purpose, including a real-time vehicle dynamics analysis system, the PC-based driving simulator and the virtual proving ground are developed by using VR(Virtual Reality) techniques. Also ABS HIL(Hardware-In-the-Loop ) simulation is performed successfully.

• Structural Engineering and Mechanics
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• v.66 no.1
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• pp.75-84
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• 2018

This study presents the reliability-based analysis of nonlinear structures using the analytical fragility curves excited by random earthquake loads. The stochastic method of ground motion simulation is combined with the random vibration theory to compute structural failure probability. The formulation of structural failure probability using random vibration theory, based on only the frequency information of the excitation, provides an important basis for structural analysis in places where there is a lack of sufficient recorded ground motions. The importance of frequency content of ground motions on probability of structural failure is studied for different levels of the nonlinear behavior of structures. The set of simulated ground motion for this study is based on the results of probabilistic seismic hazard analysis. It is demonstrated that the scenario events identified by the seismic risk differ from those obtained by the disaggregation of seismic hazard. The validity of the presented procedure is evaluated by Monte-Carlo simulation.

• New & Renewable Energy
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• v.10 no.3
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• pp.6-13
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• 2014

This paper presents a computational study of thermal performance and construction cost of horizontal ground heat exchangers (GHEs). GLD (ground loop design) simulations of various type of GHEs were carried out. Construction costs were also calculated based on standard estimating, and compared with vertical type GHE system. Besides that, dummy regression analysis was conducted to study the influence of design parameters on the simulation results in horizontal ground heat exchanger system.

• Journal of Ocean Engineering and Technology
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• v.12 no.2 s.28
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• pp.87-96
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• 1998

A numerical simulation was done to investigate the performance of thin wings in close vicinity to ground. The simulation is based on Vortex Lattice Method(VLM) and freely deforming wake elements are taken into account for a sudden acceleration case. The parameters covered in the simulation are angle of attack, aspect ratio, ground clearance, sweep angle and taper ratio. In addition, the effect of the wing endplate on the ground effect is included. The wing sections used for present computations are uncambered, cambered and S-types. The present computational results are compared with other published computational results and experimental data.

• Korean Journal of Remote Sensing
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• v.25 no.2
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• pp.107-112
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• 2009

A technique for the simulation of various kinds of ground based SAR system was developed. This is an ancillary research for the development of an ArcSAR system which uses an arc-rail as a platform for the antenna movement instead of linear rail. The results of applying conventional Deramp FFT based SAR focusing algorithm to the simulated raw signal of linear rail type ground based SAR for the point targets showed that the developed simulation technique generated accurate GB-SAR raw signal. The developed technique is now being used for the development and verification of SAR focusing algorithm for the arc-rail type ground based SAR. The simulation technique is also expected to be very useful for the purpose oriented system design and operation planning of ground based SAR technique.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.2
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• pp.1-9
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• 2019

In a ground-source heat pump (GSHP) system, a vertical ground heat exchanger (GHE) is widely accepted due to a higher thermal performance. In the vertical GHE, grout (also called grouting material) plays an important role in the heat transfer performance and the initial installation cost of the GHE. Bentonite-based grout has been used in practice because of its high swelling potential and low hydraulic conductivity. This study evaluated the thermo-physical properties of the bentonite-based grouts through lab-scale measurements. In addition, we conducted performance simulation to analyze the effect of mixed ratio of grouts on the design length and thermal performance of the vertical GHE. The simulation results show that thermally-enhanced grouts improve the heat transfer performance of the vertical GHE and thus reduce the design length of GHE pipe.