• Proceedings of the KSME Conference
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• 2002.08a
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• pp.67-70
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• 2002

In the present study a pre/post-processor program has been developed to be used with a general CFD code. This program is capable of performing the basic functions of the pre/post-processing, which include mesh generation and post processing plots. Also through perspective projection, this program can be used to check the quality of generated mesh by moving around inside the mesh. The smoke visualization can be also performed with the present program to visualize the smoke behavior in the case of fire simulation. The examples of the program execution are given in paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.895-903
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• 2005

In this paper, we present a cutter location (CL) surface deformation approach for constant scallop height tool path generation from triangular mesh. The triangular mesh model of the stereo lithography (STL) format is offset to the CL surface and then deformed in accordance with the deformation vectors, which are computed by the slope and the curvature of the CL surface. In addition, the tool path which is computed by slicing the deformed CL surface is inversely deformed by those same deformation vectors to a tool path with a constant scallop height. The proposed method is implemented, and a tool path generated by the proposed method is tested by simulation and by numerical control (NC) machining. The scallop height was found to be constant over the entire machined surface, demonstrating much better quality than that of mesh slicing, under the same constraints for machining time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.419-420
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• 2006

This paper deals with a hex-dominant mesh generation using an advancing front method for three-dimensional geometries. Hexahedral and prismatic meshes are generated inwardly by offsetting from initial boundary mesh. When the meshes intersect with each other after offsetting, overlapped meshes are improved by node relocation method. In order to generate conforming mesh, pyramid elements are inserted between hexahedral and tetrahedral elements. Sample meshes fur several geometries are presented and analized to demonstrate the effectiveness of the proposed algorithm.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.87-90
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• 1988

This paper reports a simple posteriori error estimate method for adaptive finite element mesh generation using quadratic shape function especially for the magnetic field problems. The elements of quadratic shape function have more precise solution than those of linear shape function. Therefore, the difference of two solutions gives error quantity. The method uses the magnetic flux density error as a basis for refinement. This estimator is tested on two dimensional problem which has singular points. The estimated error is always under estimated but in same order as exact error, and this method is much simpler and more convenient than other methods. The result shows that the adaptive mesh gives even better rate of convergence in global error than the uniform mesh.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2044-2046
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• 1999

In this paper, the propagation of corona streamer was simulated using finite element method(FEM) combined with Flux-Corrected Transport(FCT) algorithm. To obtain more effective grid distribution, the adaptive mesh generation scheme was also employed. The employed adaptive scheme can refine the mesh where needed. In addition, it is possible to coarsen the unnecessarily dense mesh. Two models were analyzed with proposed method. And the results are shown.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.3
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• pp.228-240
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• 2012

Morphing is a geometric interpolation technique that is often used by the animation industry to transform one form into another seemingly seamlessly. It does this by producing a large number of 'intermediate' forms between the two 'extreme' or 'parent' forms. It has already been shown that morphing technique can be a powerful tool for form design and as such can be a useful addition to the armoury of product designers. Morphing procedure itself is simple and consists of straightforward linear interpolation. However, establishing the correspondence between vertices of the parent models is one of the most difficult and important tasks during a morphing process. This paper discusses the mesh-merging method employed for this process as against the already established mesh-regularising method. It has been found that the merging method minimises the need for manual manipulation, allowing automation to a large extent.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.1
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• pp.83-88
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• 2019

Structural analysis remains as an essential part of any integrated civil engineering system in today's rapidly changing computing environment. Even with enormous advancements in capabilities of computers and mobile tools, enhancing computational efficiency of algorithms is necessary to meet the changing demands for quick real time response systems. The finite element method is still the most widely used method of computational structural analysis; a robust, reliable and automated finite element structural analysis module is essential in a modern integrated structural engineering system. To be a part of an automated finite element structural analysis, an efficient adaptive mesh generation scheme based on R-H refinement for the mesh and error estimates from representative strain values at Gauss points is described. A coefficient that depends on the shape of element is used to correct overly distorted elements. Two simple case studies show the validity and computational efficiency. The scheme is appropriate for nonlinear and dynamic problems in earthquake engineering which generally require a huge number of iterative computations.

• Journal of Institute of Convergence Technology
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• v.12 no.1
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• pp.1-5
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• 2022

This paper describes an algorithm for generating a terrain using a noise function and a height map as one of the procedural terrain generation methods. The polygon mesh data structure to represent the generated terrain concisely and render it is also described. The Perlin noise function is used as the noise technique for terrain mesh, and the height data of the terrain is generated by combining the four noise waves. In addition, the terrain height information can be also obtained from actual image data taken from the satellite. The algorithm presented in this paper generates the geometry part of the polygon topography from the height data obtained, and generated a material for texture mapping with two textures, that is, a diffuse texture and a normal texture. The validity of the terrain method proposed in this paper is verified through application examples, and its possibility can be confirmed through performance verification.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.6
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• pp.685-690
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• 2011

This paper describes a seismic analysis of chemical pump using automated mesh generation system. The use of an automated analysis system, involving FE codes together with CAD systems and FE pre- and post-processors, has provided an important step towards shortening the design process and structural optimization. The FE model, which is a FE mesh accompanied with the analysis condition, is automatically converted from the analysis model. The FE models are then automatically analyzed using the FE analysis code. This integrated FE simulation system is applied to an analysis of three-dimensional complex solid structures such as a chemical pump.

• Journal of KIISE
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• v.43 no.4
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• pp.419-429
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• 2016

Generating a 3D surface model from coronary artery segmentation helps to not only improve the rendering efficiency but also the diagnostic accuracy by providing physiological informations such as fractional flow reserve using computational fluid dynamics (CFD). This paper proposes a method to generate a triangular surface mesh using vessel structure information acquired with coronary artery segmentation. The marching cube algorithm is a typical method for generating a triangular surface mesh from a segmentation result as bit mask. But it is difficult for methods based on marching cube algorithm to express the lumen of thin, small and winding vessels because the algorithm only works in a three-dimensional (3D) discrete space. The proposed method generates a more accurate triangular surface mesh for each singular vessel using vessel centerlines, normal vectors and lumen diameters estimated during the process of coronary artery segmentation as the input. Then, the meshes that are overlapped due to branching are processed by mesh merging and merged into a coronary mesh.