• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.14-20
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• 2014

This study, the reliability of weapon systems acquisition and research and development in order to increase the effect of the modeling and simulation method has been studied using computational fluid dynamics. Weapon system acquisition, Test & Evaluation for use in the modeling and simulation can reduce the reliability of the time and cost savings and possible predictions and verification, and can provide useful data. However, the current weapon system acquisition and active use of modeling and simulation and verification do not even use the software are restricted. In this study, using computational fluid dynamics (CFD) modeling and simulation using the GAMBIT and FLUENT modeling and simulation was performed. The result is better than previous research results were confirmed in future weapon systems acquisition and research and development are expected to be actively used.

• Korean Journal of Computational Design and Engineering
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• v.7 no.4
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• pp.240-247
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• 2002

Most commercial CAD systems provide parametric modeling functions, and by using these capabilities designers can edit a CAD model in order to create design variants. It is necessary to transfer parametric information during a CAD model exchange to modify the model inside the receiving system. However, it is not possible to exchange parametric information of CAD models based on the cur-rent version of STEP. The designer intents which are contained in the parametric information can be lost during the STEP transfer of CAD models. This paper introduces a hybrid CAB model translator, which also uses the feature tree of commercial CAD systems in addition to the macro file to allow transfer of parametric information. The macro-parametric approach is to exchange CAD models by using the macro file, which contains the history of user commands. To exchange CAD models using the macro-parametric approach, the modeling commands of several commercial CAD systems are analyzed. Those commands are classified and a set of standard modeling commands has been defined. As a neutral fie format, a set of standard modeling commands has been defined. Mapping relations between the standard modeling commands set and the native modeling commands set of commercial CAD systems are defined. The scope of the current version is limited to parts modeling and assemblies are excluded.

• Geomechanics and Engineering
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• v.1 no.1
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• pp.53-74
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• 2009

In recent years, several computer-aided pattern recognition and data mining techniques have been developed for modeling of soil behavior. The main idea behind a pattern recognition system is that it learns adaptively from experience and is able to provide predictions for new cases. Artificial neural networks are the most widely used pattern recognition methods that have been utilized to model soil behavior. Recently, the authors have pioneered the application of genetic programming (GP) and evolutionary polynomial regression (EPR) techniques for modeling of soils and a number of other geotechnical applications. The paper reviews applications of pattern recognition and data mining systems in geotechnical engineering with particular reference to constitutive modeling of soils. It covers applications of artificial neural network, genetic programming and evolutionary programming approaches for soil modeling. It is suggested that these systems could be developed as efficient tools for modeling of soils and analysis of geotechnical engineering problems, especially for cases where the behavior is too complex and conventional models are unable to effectively describe various aspects of the behavior. It is also recognized that these techniques are complementary to conventional soil models rather than a substitute to them.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.93-103
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• 2015

In this study, we organize and explain various ways to construct 3D models in the 2D plane using Geogebra, mathematical education software that enables us to visualize dynamically the interaction between algebra and geometry. In these ways, we construct three unit vectors for 3 dimensions at a point on the Cartesian coordinates, on the basis of which we can build up the 3D models by putting together basic mathematical objects like points, lines or planes. We can apply the ways of constructing the 3 dimensions on the Cartesian coordinates to modeling of various structures in the real world, and have chances to translate, rotate, zoom, and even animate the structures by means of slider, one of the very important functions in Geogebra features. This study suggests that the visualizing and dynamic features of Geogebra help for sure to make understood and maximize learning effectiveness on mechanical modeling or the 3D CAD.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.78-84
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• 2008

This paper presents a fast modeling technique of virtual pottery using force feedback based on a circular sector element method. Previous techniques for simulating deformable objects such as finite element method (FEM) are limited in real-time haptic rendering due to their complexity and expensive computational cost. In our model, circular sector elements which fully represent features of pottery's shape are closely gathered and piled together. This allows efficient deformable object modeling through a decrease in the number of elements and reducing computational cost.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.341-349
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• 2002

The radar method is becoming one of the major nondestructive testing(NDT) techniques lot concrete structures. Numerical modeling of electromagnetic wane is needed to analyze radar measurement results. Finite difference-time domain(FD-TD) method can be used to simulate electromagnetic wave propagation through concrete specimens. Five concrete specimens with different thickness are modeled in 3-dimension. Radar modeling results compare measurement results to find backface of the concrete specimens and measure thickness of the concrete specimens.

• Journal of computational fluids engineering
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• v.11 no.2 s.33
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• pp.32-39
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• 2006

A heat dissipation modeling method of EEE parts is developed for thermal design and analysis of an satellite electronic equipment. The power consumption measurement value of each functional breadboard is used for the heat dissipation modeling method. For the purpose of conduction heat transfer modeling of EEE parts, surface heat model using very thin ignorable thermal plates is considered instead of conventional lumped capacity nodes. These modeling methods are applied to the thermal design and analysis of CTU EM and EQM and verified by thermal cycling and vacuum tests.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.333-340
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• 2006

In these days the floor vibration is beginning to make its appearance of the environmental dispute in apartment building. Standard floor system are suggested for the settlement of this issue by government. The sound of floor impact sound is needed to secure comfortable quality in housing. Also, it is required an accurate analysis and a proper evaluation for floor vibration. Refine model is necessary for the floor system of housing to analyze accurately the floor vibration. But this refine model is not efficient because it is required so much running time for vibration analysis and it is difficult of modeling of standard floor slab. In this paper, new modeling methods of standard floor slab are proposed for the accurate rigidity evaluation. By using the new modeling method, the accurate vibration response can be obtained and can accurately evaluate the rigidity of standard floor system with resilient materials. Therefore the proposed modeling method is of practical use for vibration analysis of floor system of apartment building.

• Computers and Concrete
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• v.12 no.4
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• pp.443-498
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• 2013

A detailed finite element modeling is presented for the simulation of the nonlinear behavior of reinforced concrete structures which manages to predict the nonlinear behavior of four different experimental setups with computational efficiency, robustness and accuracy. The proposed modeling method uses 8-node hexahedral isoparametric elements for the discretization of concrete. Steel rebars may have any orientation inside the solid concrete elements allowing the simulation of longitudinal as well as transverse reinforcement. Concrete cracking is treated with the smeared crack approach, while steel reinforcement is modeled with the natural beam-column flexibility-based element that takes into consideration shear and bending stiffness. The performance of the proposed modeling is demonstrated by comparing the numerical predictions with existing experimental and numerical results in the literature as well as with those of a commercial code. The results show that the proposed refined simulation predicts accurately the nonlinear inelastic behavior of reinforced concrete structures achieving numerical robustness and computational efficiency.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.512-517
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• 2011

This study is intended for validation of numerical modeling of a residential building which is made to simulate a phenomenon of fire extension from floor to floor. A common residential building which has the area of 80m2 each floor and some combustibles were chosen for numerical modeling. The combustible models were verified through comparing results of numerical simulations and real fire tests. For computational analysis, the Fire Dynamics Simulator was used with Large Eddy Simulation model for turbulence. Consequently, fire-intensity was well predicted and flash-over of rooms were successfully estimated.