• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.22-25
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• 2001

A new mesh-topology model of IGBT is presented. It can be applied to the research of IGBT's static and dynamic latch-up (du/dt latch-up, overheat latch-up, overload latch-up, overvoltage latch-up) as well as the switching on-off behavior of the device. The overcurrent latch-up is analyzed.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.37-44
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• 1997

A dadaptive refinement tetrahedron mesh has been presented for using in full band GaAs monte carlo simulation. A uniform tetrahedron mesh is used without regard to energy values and energy variety in case of the past full band simulation. For the uniform tetrahedron mesh, a fine tetrahedron is demanded for keeping up accuracy of calculation in the low energy region such as .GAMMA.-valley, but calculation time is vast due to usin gthe same tetrahedron in the high energy region. The mesh of this study, thererfore, is consisted of the fine mesh in the low energy and large variable energy region and rough mesh n the high energy. The density of states (DOS) calculated with this mesh is compared with the one of the uniform mesh. The DOS of this mesh is improved th efive times or so in root mean square error and the ten times in the correlation coefficient than the one of a uniform mesh. This refinement mesh, therefore, can be used a sthe basic mesh for the full band GaAs monte carlo simulation.

• Solar Energy
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• v.19 no.3
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• pp.43-51
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• 1999

Axisymmetric circular water jet impinges against rectangular heated surface with uniform hear flux and wire-mesh screens are set up in the nozzle-to-heater space to augment heat transfer. In the free jet region to be used them, pressure drop and intensive turbulence flow was brought up. When water jet system is not used wire-mesh screens, maximum heat transfer appears in the stagnation point and the secondary maximum appears X/D=4 but it disappears when they are is used. In the low velocity(Vo<6.0m/s), coarse mesh-screen enhanced heat transfer but fine mesh-screens inpeded heat transfer. In the high velocity(Vo>6m/s), all of them enhanced heat transfer. Average Nusselt number of experimental system to be used wire-mesh screens was promoted $4{\sim}6$times than that of simple water jet system. The stagnation heat transfer of experimental system to be used wire-mesh screens was augmented 6times that of simple water jet system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.6
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• pp.853-859
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• 2001

This paper describes the extended topological clean up procedures to improve the quality of unstructured triangular meshes. As a postprocessing step, topological improvement procedures are applied both for elements that are interior to the mesh and for elements connected to the boundary and then Laplacian-like smoothing is used by default. Previous clean up algorithms are limited to eliminate the nodes of degree 3,4,8,9,10 and pairs of nodes of degree 5. In this study, new clean up algorithms which minimize the triple connection structures combined with degree 5 and 7 (ie ; 5-7-5, 7-7-5, 7-5-7 etc) are added. The suggested algorithms are applied to two example meshes to demonstrate the effectiveness of the approach in improving element quality in a finite element mesh.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.7
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• pp.587-594
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• 2013

With the development of web 2.0 and the rapid diffusion of smart devices, current web service, which only provides very limited information and service, has been transformed into user-friendly and comprehensive web service called mash-up service. Mash-up service is defined as comprehensive service that is created by combining variety of web services. When composing a mesh-up service, Open API is used as web service interface. Current mash-up service, however, has fundamental problem in that it could not satisfy the various needs of users who want I-centric personalized service because it is developed and provided by service developers. To overcome these obstacles, a lot of studies on mesh-up framework are being performed for improving mash-up proess though, it is still in beginning stage. In this paper, we introduce an API selection and compostion method as the key technology for mesh-up framework that support the automatic creation of mesh-up service.

• Journal of the Korea Computer Graphics Society
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• v.15 no.2
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• pp.1-8
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• 2009

This paper introduces a virtual dress up system, according to user's input model and garment image. At first step, we deform the garment image by using skeleton structures and ARAP method. Next step, sampling the boundary points and find their matching vertices which are used for optimizing the boundary fitting. In 2D rendering of the dress up, they have some unrealistic results, so we reconstruct the garment mesh to the 3D mesh. Rendering from the reconstructed 3D mesh, we can get the final dress up result. We present that our system produce a visually plausible and well-fitted virtual dress up results.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.616-625
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• 2011

There are two representative geometry rendering methods. One is Geometry Clipmaps, another is ROAM 2.0. We propose an extended Geometry Clipmaps algorithm which does not focus on CPU operation but the GPU for faster and wider visibility area. The extended algorithm presents mesh configuration method of each level by LOD, how to configurate Mesh network between levels, mesh block method for rendering optimization using VFC, and image mapping method to get high resolution up to 1 m.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1786-1791
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• 2016

The damage has occurred inside the semiconductor pattern When using conventional wet station for semiconductor. It was used for electrolytic ion water generator in order to prevent damage to the semiconductor pattern. It was designed and developed a flow path electrode and the mesh electrode to check the efficiency of the electrode. And It confirmed the expected results through the simulation of the flow path. and ORP were measured in accordance with the current and voltage of mesh electrode and flow paht electrodes. Flow path electrode 22A is 3V, up to pH 9.8, the value of ORP-558mV was measured and the mesh electrode was measured up to pH 9.8, ORP -350mV.

• Korean Journal of Computational Design and Engineering
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• v.12 no.2
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• pp.109-117
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• 2007

Three-dimensional mesh models have been widely used in various applications such as simulations, animations, and e-catalogs. In such applications the normal vectors of mesh models are used mainly for shading and take up the major portion of data size and transmission time paper over networks. Therefore a variety of techniques have been developed to compress them efficiently. In this paper, we propose the MOEC (Modified Octree Encoding Compression) algorithm, which allow multi lever compression ratios for 3D mesh models. In the algorithm, a modified octree has nodes representing their own positions and supporting a depth of the tree so that the normal vectors are compressed up to levels where the shading is visually indistinguishable. This approach provides efficient in compressing normals with multi-level ratios, without additional encoding when changing in compression ratio is required.

• Korean Journal of Computational Design and Engineering
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• v.11 no.1
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• pp.20-26
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• 2006

This paper presents a procedure to compute pencil curves from a triangular mesh which is offset with the radius of a given ball-end mill. An offset triangular mesh has numerous self-intersections caused by an abundance of invalid triangles, which do not contribute to the valid CL-surface. Conceptually, we can obtain valid pencil curves by combining all intersections tying on the outer skin of the offset triangular mesh, i.e., the valid CL-surface. The underlying concept of the proposed algorithm is that visible intersections are always valid for pencil curves, because visible intersections lie on the outer skin of the offset model. To obtain the visibility of intersections efficiently, the proposed algorithm uses a graphics board, which performs hidden surface removal on up to a million polygons per second.