• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.1
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• pp.55-63
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• 1998

This paper presents a new maching algorithm by Hopfield Neural Network for 3-D object recognition. In the proposed method, a model object is represented by a set of polygons in a single coordinate. And each polygon is described by a set of features; feature attributes. In case of 3-D object recognition, the scale and poses of the object are important factors. So we propose a strategy for 3-D object recognition independently to its scale and poses. In this strategy, the respective features of the input or the model objects are changed to the startegical constants when they are compared with one another. Finally, we show that the proposed method has a robustness through the results of experiments which included the classification of the input objects and the matching sequence to its 3-D rotation and scale.

• Korean Journal of Computational Design and Engineering
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• v.10 no.2
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• pp.107-113
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• 2005

Octree-based algorithm is developed for machining simulation. Most of commercial machining simulators are based on Z map model, which have several limitations to get a high precision in 5 axis machining simulation. Octree representation is three dimensional decomposition method. So it is expected that these limitations be overcome by using octree based algorithm. By using the octree model, storage requirement is reduced. And also recursive subdivision was processed in the boundaries, which reduces useless computation. The supersampling method is the most common form of the anti-aliasing and usually used with polygon mesh rendering in computer graphics. Supersampling technique is applied for advancing its efficiency of the octree algorithm.

• Transactions of Materials Processing
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• v.23 no.1
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• pp.16-22
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• 2014

The current study presents a simple setup method for making teeth models using a three-axis CNC milling machine. Physical teeth models can be made by several methods: casting, machining, and three-dimensional printing. Since the shape of a teeth model requires five-axis machining, the machining of a teeth model using a three-axis CNC milling machine requires careful setup operations. In this paper a simple datum shape is designed within the work piece of the teeth model. The datum shape is an n-sided prism with regular n-polygon ends and rectangular sides. In the present study a 12-sided prism is used, which easily makes 30 degree rotations for finish machining. The proposed setup approach does not require any special tools for making the teeth model using a three-axis CNC milling machine. A test was run and the results show that the proposed approach is useful for experimental makings with the limited facilities available.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.877-886
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• 2009

In this paper, we propose a new method for the design and implementation of Cloth Simulation System for 3D fashion shopping mall based on Web. Web 3D shopping mall is implemented by using a Web3D authoring tool, ISB, which provides easy mouse operation. 3D human models and cloth item model are designed by low polygon modeling method of 3D MAX. The designed 3D human models and cloth item model are exported to XML file. Finally, 3D human models and cloth item model are displayed and animated on the Web by using ActiveX control based on DirectX. We also implemented textile palette and mapped it to clothes model by using alpha blending during simulation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.23-26
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• 2010

In this paper, we propose a new method for the design and implementation of a web-based 3D fashion shopping mall. Web 3D shopping mall is implemented by using a Web3D authoring tool, ISB, which provides easy mouse operation. 3D human models and cloth item model are designed by low polygon modeling method of 3D MAX. The designed 3D human models and cloth item model are exported to XML file. Finally, 3D human models and cloth item model are displayed and animated on the Web by using ActiveX control based on DirectX. We also implemented textile palette and mapped it to clothes model by using alpha blending during simulation.

• Computers and Concrete
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• v.23 no.1
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• pp.69-80
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• 2019

Modeling approach for mesoscopic model of concrete depicting mass transportation and physicochemical reaction is important since there is growing demand for accuracy and computational efficiency of numerical simulation. Mesoscopic numerical simulation considering binder, aggregate and Interfacial Transition Zone (ITZ) generally produces huge number of DOFs, which is inapplicable for full structure. In this paper, a three-dimensional multiscale approach describing three-phase structure of concrete was discussed numerically. An effective approach generating random aggregate in polygon based on checking centroid distance was introduced. Moreover, ITZ elements were built by parallel expanding the surface of aggregates on inner side. By combining mesoscopic model including full-graded aggregate and macroscopic model, cases related to diffusivity and thickness of ITZ, volume fraction and grade of aggregate were studied regarding the consideration of multiscale compensation. Results clearly showed that larger analysis model in multiscale model expanded the diffusion space of chloride ion and decreased chloride content in front of rebar. Finally, this paper addressed some worth-noting conclusions about the chloride distribution and rebar corrosion regarding the configuration of, rebar diameter, concrete cover and exposure period.

• Economic and Environmental Geology
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• v.27 no.5
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• pp.479-489
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• 1994

In this paper, the iterative least-squares inversion method is used to determine shapes and density contrasts of 2-D structures from the gravity data. The 2-D structures are represented by their cross-sections of N-sided polygons with density contrasts which are constant or varying with depth. Gravity data are calculated by theoretical formulas for the above structure models. The data are considered as observed ones and used for inversions. The inversions are performed by the following processes: I) polygon's vertices and density contrast are initially assumed, 2) gravity are calculated for the assumed model and error between the true (observed) and calculated gravity are determined, 3) new vertices and density contrast are determined from the error by using the damped least-squares inversion method, and 4) final model is determined when the error is very small. Results of this study show that the shape and density contrast of each model are accurately determined when the density contrast is constant or vertical density gradient is known. In case where the density gradient is unknown, the inversion gives incorrect results. But the shape and density gradient of the model are determined when the surface density contrast is known.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.109-116
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• 2005

3D Spatial Data, namely 3D Urban CG model express the building, road, river in virtual world and accumulate, manage the data in the GIS system. It is important infrastructure which expected in many usages. Recently 3D CG urban model needs much manual effort, time and costs to build them. In this paper, we introduce the integration of GIS, CG and automatic production of the $\lceil$3D Spatial Data Infrastructure$\rfloor$. This system make filtering, divide the polygon, generate the outlines of the GIS building map, design the graphic and property information and finally make automatic 3D CG models.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.331-336
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• 2015

The texture mapping used for the low-polygon models is one of the important workflows in the graphical representation of the 3D game. Only one hand painted texture is mapped on the surface of the 3D model and represents the color of the material and visual sense of touching by itself in that process. In the 3D game graphics, it is very important to visualize the textile sensation such as protruding and denting. It can be interpreted by the Gestalt Law to recognize a plane as a 3D sense of volume. Moreover, the concept of Affordance is necessary to recognize and perceive the textile sensation. It means visual recognizing of that relationship in the learning process. In this paper, The questionnaire survey targeting 3D game graphic designers is carried out. By analyzing the survey results, we suggest the important characteristic in the process of making hand painted texture.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.135-140
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• 2015

The Cyber-Physical Systems (CPS) complexly perform modeling and simulation (M&S) for the various embedded systems. In this case, due to use diverse formatted models, we suggest to apply with the SEDRIS to systematically manage the different formatted data on M&S. The SEDRIS can reduce time and cost with reusing and interoperating environment data developed in the specific domain. To do this, we should input the data transformed the height map for terrain representation in a simulator into raster data of SEDRIS for which interoperate between the existed simulator and the SEDRIS. To solve the problem, we propose the transformation method to transfer the polygon data from RAW file used in terrain representation. With the proposed method, we can provide two advantages. First, it can possibly express the environment data into SEDRIS. Second, we can see the terrain like an image file through a viewer. Therefore, even non-expert easily constructs the terrain environment data.