• Journal of the Korean Society for Railway
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• v.14 no.1
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• pp.11-18
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• 2011

This paper proposed a new 2-D multi-body dynamic modeling technique to analyze overriding behaviors taking place during train collision. This dynamic model is composed of nonlinear springs, dampers and masses by considering the deformable characteristics of carbodies as well as energy absorbing structures and components. By solving this dynamic model for rollingstock, energy absorbing capacities of collision elements, accelerations of passenger sections, impact forces applied to interconnecting devices, and overriding displacements can be well estimated. For a case study, we chose KHST (Korean High Speed Train), obtained crush characteristic data of each carbody section from 3-D finite element analysis, and established a 2-D multi-body dynamic model. This 2-D dynamic model was simulated under the train-to-train collision scenarios, and evaluated with 3-D virtual testing model. It was founded from the simulation results that this 2-D dynamic model could well predict overriding behaviors, and the modeling technique of carbody deformation was very important in overriding estimation.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.222-227
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• 2008

This study is focused on an integrated numerical modeling enabling one to investigate the dynamic behavior and failure of 2-D textile composite and 3-D orthogonal woven composite structures weakened by micro-cracks and subjected to an impact load. The integrated numerical modeling is based on: I) determination of governing equations via a three-level hierarchy: micro-mechanical unit cell analysis, layer-wise analysis accounting for transverse strains and stresses, and structural analysis based on anisotropic plate layers, II) development of an efficient computational approach enabling one to perform transient response analyses of 2-D plain woven and 3-D orthogonal woven composite structures featuring the matrix cracking and exposed to time-dependent loads, III) determination of the structural characteristics of the textile-layered composites and their degraded features under various geometrical yarn shapes, and finally, IV) assessment of the implications of stiffness degradation on dynamic response to impact loads.

• Structural Engineering and Mechanics
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• v.51 no.6
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• pp.1067-1089
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• 2014

In this paper, three dimensional static and dynamic analyses of two dimensional functionally graded annular sector plates have been investigated. The material properties vary through both the radial and axial directions continuously. Graded finite element and Newmark direct integration methods have been used to solve the 3D-elasticity equations in time and space domains. The effects of power law exponents and different boundary conditions on the behavior of FGM annular sector plate have been investigated. Results show that using 2D-FGMs and graded elements have superiority over the homogenous elements and 1D-FGMs. The model has been compared with the result of a 1D-FGM annular sector plate and it shows good agreement.

• Journal of Korea Game Society
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• v.9 no.2
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• pp.125-133
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• 2009

Game artificial intelligence is usually used to provide intelligent and adjusted game environment for user. Previously, it was used for Non-player character(NPC) playing a role of a company or an enemy through collecting and analyzing a user's behaviour. However, it was just mimicking the user's behavior. This paper introduces a method to change game environment by analyzing a user's game behavior. Game behavior data has been used to understand user's game preference. Also, the user's preference was used to provide more active game environment by reflecting decision of geographical features, items and distribution of NPC. For experiment of the suggested method, we utilized a real 2D action game and confirmed the game environment which changing properly according to the user's game play.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.269-279
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• 2022

In this research, a series of dynamic numerical analysis were carried out for deep underground building structures under the various earthquake conditions. Dynamic numerical analysis model was developed based on the PLAXIS2D and calibrated with centrifuge test data from Kim et al. (2016). The hardening soil model with small strain stiffness (HSSMALL) was adopted for soil constitutive model, and interface elements was employed at the interface between plate and soil elements to simulate dynamic interaction effect. In addition, parametric study was performed for fixed condition and embedded depth. Finally, the dynamic behavior of underground building structure was thoroughly analyzed and evaluated.

• Journal of the Korean GEO-environmental Society
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• v.20 no.12
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• pp.5-14
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• 2019

Recently in Korea, researches on seismic analyses for high-rise buildings in a large city have been increasing because earthquakes have occurred. However, the ground conditions are not included in most of seismic researches and analyses on a high-rise building. Also the influence of the predominant period of a seismic wave is not considered in reality. Therefore, in this study, the influence of the predominant period of a seismic wave on the dynamic behavior of high-rise buildings was analyzed based on the complete system model which can consider the grounds. For this purpose, 2D dynamic analyses based on a linear time history analysis were performed using MIDAS GTS NX, a finite-element based program. Dynamic behavior was analyzed in terms of horizontal displacements, drift ratios, bending stresses, and building weak zones. As a result, in overall, the dynamic response of a high-rise building become bigger as the predominant period of a seismic wave become longer. It was also found that the predominant period had a greater influence than other parameters, ground conditions and peak ground acceleration.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.113-120
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• 1999

When we design the large rockfill dams the safety of dams against the quake must be considered. Generally pseudostatic analysis method has been used for slope stability and evaluation of safety but the case of dynamic response analysis of earthquake was not in general in Korea. Therefore we need to perform the dynamic response analysis of rockfill dams from these results we analyze the dynamic behavior of dam body such as response displacement and response acceleration. consequently we analyse the selected model of rockfill dam using the FLAC-2D (FDM) program.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.4
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• pp.45-53
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• 1999

The microbial organisms named "Pseudomonas sp. LK-14" were isolated from farm land and shallow river sediment, activated, augmented and identified; which were using 2,4-D (2,4-Dichlorophenoxyacetic acid) as a sole carbon source and energy source. 2,4-D removal efficiency of LK-14 with 2,4-D sole carbon source (reactor S) were higher than that of Activated Sludge with 2,4-D sole carbon source (reactor A). Dynamic bioligical reaction kinetic parameters (sole carbon source was 2,4-D) obtained from batch reactor experiments were ${\mu}_{max}$ $0.105hr^{-1}$, $K_{s,24D}$ 15.64mg/L, $K_{i,24D}$ $1.94h^{r-1}$, $Y_{24D}$ 0.39 for LK-14 and ${\mu}_{max}$ $0.008hr^{-1}$, $K_{s,24D}$ 26.95mg/L, $K_{i,24D}$ $1.75hr^{-1}$, $Y_{24D}$ 0.10 for Activated Sludge. Using these parameters, we could predict the behaviors of 2,4-D substrate utilized by LK-14 and Activated Sludge in batch reactors. The kinetic parameters are enable to predict the 2,4-D substrate and microbial population behavior entering into wastewater treatment plants by using unsteady states dynamic simulation modeling technique.

• Journal of ILASS-Korea
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• v.18 no.2
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• pp.94-99
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• 2013

The spherically-symmetric burning of an isolated droplet is a dynamic problem that involves the coupling of chemical reactions and multi-phase flow with phase change. For the improved understanding of these phenomena, this paper presents the numerical results on the n-heptane droplet combustion conducted at a 1 atm ambient pressure in three different initial droplet diameter ($d_0$). The main purpose of this study is to provide basic information of droplet burning, extinction and flame behavior of n-heptane and improve the ability of theoretical prediction of these phenomena. To achieve these, the numerical analysis was conducted in terms of normalized droplet diameter ($d/d_0$), flame diameter ($d_f$) and flame standoff ratio (FSR) under the assumptions that the droplet combustion can be described by both the quasi-steady behavior for the region between the droplet surface and the flame interface and the transient behavior for the region between the flame interface and ambient surrounding.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.10a
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• pp.139-146
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• 1996

The torsion tests in the range of 900~1100$^{\circ}C$ and 5.0X10-2~5.0X100/sec were performed to study the high temperasture deformation behavior kinetics of 304 stainless steels. The flow curves and microstructures exhibited the characteristic of dynamic recrystallization(DRX). The relationship between the critical strain($\varepsilon$c) for the initiation of dynamic recrystallization and the peak strain($\varepsilon$p) could be expressed as $\varepsilon$c=0.73$\varepsilon$p. The dependence of the flow stress on temperature(T) and stain rate($\varepsilon$) was expressed by hyperbolic sine law, $\varepsilon$=2.75X1014 (sinh 0.076$\sigma$)5.26 exp(-379.55kJ/mol). Under the Zener-Hollomon parameter, Z value of 1013 order, it was found that the grain size was 20${\mu}$m. The relationship between the grain size, dDRX and Z parameter was expressed as dDRX =139.48-7.33 log Z.