• The KIPS Transactions:PartA
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• v.11A no.5
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• pp.365-372
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• 2004

Recently, the studies for mesh simplification have been increased according to the application area of the complicate 3D mesh models has been expanded. This paper introduces a novel method for mesh simplification which uses the properties of the mesh model in addition to the geometric locations of the model. The information of the 3D mesh model Includes surface properties such as color, texture, and curvature information as well as geometic information of the model. The most of current simplification methods adopt such geometric information and surface properties individually for mesh simplification. However, the proposed simplification method combines the geometric information and solace properties and applies them to the simplification process simultaneously. In this paper, we exploit the extended geometry based quadric error metric(QEM) which relatively allows fast and accurate geometric simplification of mesh. Thus, the proposed mesh simplification utilizes the quadric error metric based on geometric information and the surface properties such as color, normal, and texture. The proposed mesh simplification method can be expressed as a simple quadric equation which expands the quadric error metric based on geometric information by adding surface properties such as color, normal, and texture. From the experimental results, the simplification of the mesh model based on the proposed method shows the high fidelity to original model in some respects such as global appearance rather than using current geometry based simplification.

• Journal of the Korea Computer Graphics Society
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• v.7 no.3
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• pp.9-18
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• 2001

Feature detection is important in various mesh processing techniques, such as mesh editing, mesh morphing, mesh compression, and mesh signal processing. In this paper, we propose a geometric snake as an interactive tool for feature detection on a 3D triangular mesh. A geometric snake is an extension of an image snake, which is an active contour model that slithers from its initial position specified by the user to a nearby feature while minimizing an energy functional. To constrain the movement of a geometric snake onto the surface of a mesh, we use the parameterization of the surrounding region of a geometric snake. Although the definition of a feature may vary among applications, we use the normal changes of faces to detect features on a mesh.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.499-505
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• 2018

Most of 3D indoor spatial data recently constructed by many projects merely focus on the visualization rather than geospatial information applications. The 3D indoor data for visualization in 3DS or COLLADA format are based on triangular mesh representation. In order to implement meaningful applications, we need however more meaningful information in 3D indoor spatial data than visualization data in triangular meshes. For this reason, an OGC (Open Geospatial Consortium) standard, called IndoorGML(Indoor Geographic Markup Language) was published to meet the requirements on 3D indoor spatial data for several geospatial applications for indoor space more than simple visualization. It means that it becomes a critical functional requirement to convert triangular mesh representation in 3DS or COLLADA to IndoorGML. In this paper we propose a framework of the conversion, which consists of geometric, topological, and semantic construction of data from triangular meshes. An experiment carried out to validate the proposed framework is also presented in the paper.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.124-127
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• 2002

This paper presents a 3D shape optimization algorithm for electromagnetic devices using the design sensitivity analysis with finite element method. The structural deformation analysis based on the deformation theory of the elastic body under stress is used for mesh renewing. The design sensitivity and adjoint variable formulae are derived for the 3D nonlinear finite element method with edge element. The proposed algorithm is applied to the shape optimization of 3D electromagnet to get a uniform flux density at the air gap.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.43.1-43.5
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• 2019

Background: Reconstructive surgery is often required for tumors of the oral and maxillofacial region, irrespective of whether they are benign or malignant, the area involved, and the tumor size. Recently, three-dimensional (3D) models are increasingly used in reconstructive surgery. However, these models have rarely been adapted for the fabrication of custom-made reconstruction materials. In this report, we present a case of maxillary reconstruction using a laboratory-engineered, custom-made mesh plate from a 3D model. Case presentation: The patient was a 56-year-old female, who had undergone maxillary resection in 2011 for intraoral squamous cell carcinoma that presented as a swelling of the anterior maxillary gingiva. Five years later, there was no recurrence of the malignant tumor and a maxillary reconstruction was planned. Computed tomography (CT) revealed a large bony defect in the dental-alveolar area of the anterior maxilla. Using the CT data, a 3D model of the maxilla was prepared, and the site of reconstruction determined. A custom-made mesh plate was fabricated using the 3D model (Okada Medical Supply, Tokyo, Japan). We performed the reconstruction using the custom-made titanium mesh plate and the particulate cancellous bone and marrow graft from her iliac bone. We employed the tunneling flap technique without alveolar crest incision, to prevent surgical wound dehiscence, mesh exposure, and alveolar bone loss. Ten months later, three dental implants were inserted in the graft. Before the final crown setting, we performed a gingivoplasty with palate mucosal graft. The patient has expressed total satisfaction with both the functional and esthetic outcomes of the procedure. Conclusion: We have successfully performed a maxillary and dental reconstruction using a custom-made, pre-bent titanium mesh plate.

• Journal of Korea Game Society
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• v.6 no.3
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• pp.3-12
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• 2006

Path-finding, one of the traditional Game A.I. problems, becomes an important issue to make games more realistic. Due to the limited resources in the computer system, path-finding systems sometimes produce a simplified and unrealistic path. The most relent researches have been focused on the path-finding avoiding only static obstacles. Various moving obstacles are however deployed in real games, a method avoiding those obstacles and producing a smooth path is necessary. In this paper, navigation mesh is used to represent 3D space and its topological characteristics are used for path-finding. Intellectual repulser and attractor are also used to avoid moving obstacles and to find an optimal path. We have evaluated the path produced by the method proposed in this paper and verified its usability in real game.

• Korean Journal of Human Ecology
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• v.21 no.3
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• pp.539-550
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• 2012

In-depth knowledge of fabric microstructure is essential for understanding clothing comfort since it plays a significant role in heat and mass transfer between the human body and clothing. In this study, a novel method was employed for investigating 3D surfaces and solid construction characteristics of specific fabrics by using a reverse engineering technique. The surface construction data were obtained by a confocal laser scanning microscope and then manipulated by a 3D analysis program. Triangle mesh was used for connecting each 3D point, with clouds and fabric surface characteristics created by rendering techniques. For generating a 3D solid model, determinants of radius of curvature was used. According to the proposed method, actual surface expression of the real fabric was achieved successfully. The results from this methodology can be applied to the detailed analysis of clothing comfort that is highly influenced by the microstructure of the fabric.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1441-1446
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• 2009

Numerical analysis is a powerful method in evaluating the soil-pile-structure interaction under the dynamic loading, and this approach has been applied to the practical area due to the development of computer technology. Finite Difference Method, one of the most popular numerical methods, is sensitive to the shape and the number of mesh. However, the trial and error approach is conducted to obtain the accurate results and the reasonable simulation time because of the lack of researches about mesh size and the number. In this study, FLAC 3D v3.1 program(FDM) is used to simulate the dynamic pile model tests, and the numerical results are compared with the 1G shaking table tests results. With the different size and shape of mesh, the responses of pile behavior and the simulation time are estimated, and the optimum mesh sizes in dynamic analysis of single pile is studied.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1147-1152
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• 2005

Two experiments were conducted to evaluate the effects of dietary Biotite V (BV) supplementation on growth performance, nutrients digestibility and fecal noxious gas content in finishing pigs. In Exp. 1, a total of eighty pigs (initial body weight 88.0${\pm}$1.35 kg) were used in a 35-d growth trial. Pigs were blocked by weight and allotted to five dietary treatments in a randomized complete block design. There were four pigs per pen and four pens per treatment. Dietary treatments included: 1) Control (CON; basal diet), 2) 200 mesh BV1.0 (basal diet+200 mesh Biotite V 1.0%), 3) 325 mesh BV1.0 (basal diet+325 mesh Biotite V 1.0%), 4) 200 mesh BV2.0 (basal diet+200 mesh Biotite V 2.0%) and 5) 325 mesh BV2.0 (basal diet+325 mesh Biotite V 2.0%). Through the entire experimental period, there were no significant differences in ADG, ADFI and gain/feed among the treatments (p>0.05). With the addition of Biotite V in diet, DM and N digestibilities were increased significantly (p<0.01). Also, Ca and P digestibilities tended to increase in pigs fed Biotite V supplemented diet (p<0.01) compared to pigs fed control diet. Supplementation of Biotite V in diet reduced the fecal $NH_3-N$ and volatile fatty acid (VFA) compared to CON treatment (p<0.01). In Exp. 2, a total of sixty four pigs (initial body weight 84.0${\pm}$1.05 kg) were used in a 35-d growth trial. Pigs were blocked by weight and allotted to four dietary treatments in a randomized complete block design. There were four pigs per pen and four pens per treatment. Dietary treatments included: 1) LP (low protein diet), 2) HP (high protein diet), 3) LP+BV (low protein diet+325 mesh Biotite V 1.0%) and 4) HP+BV (high protein diet+325 mesh Biotite V 1.0%). Through the entire experimental period, ADG and gain/feed tended to increase in HP and HP+BV treatments, however, there were no significant differences (p>0.05) among the treatments. With the addition of Biotite V in diets, digestibilities of nutrients (DM, N, Ca and P) were increased significantly (p<0.01). The addition of Biotite V in diets reduced the ammonia emissions in feces (p<0.01). Supplementation of Biotite V in diets also reduced the fecal propionic acid, butyric acid and acetic acid (p<0.01) compared to pigs fed diets without Biotite V. In conclusion, supplementation of Biotite V can increase nutrients digestibility and reduce fecal $NH_3-N$ and volatile fatty acid (VFA) concentrations in finishing pigs.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.373-379
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• 2001

There is a big issue to generate 3D hexahedral finite element (FE) model, since a process to divide the whole domain into several simple-shaped sub-domains is required before generating a continuous mesh with mapped mesh generators. In general, it is nearly impossible to set up proper division numbers interactively to keep mesh connectivity between sub-domains on a complicated arbitrary-shaped domain. If mesh continuity between sub-domains is not required in an analysis, this complicated process can be omitted. Element-free Galerkin method (EFGM) can accept discontinuous meshes, which only requires nodal information. However it is difficult to choose a reasonable influenced domain in moving least squares scheme with non-uniformly distributed nodes in discontinuous FE models. A new FE scheme fur discontinuous mesh is proposed in this paper by applying improved EFGM with some modification to derive FE approximated function in discontinuous parts. Its validity is evaluated on linear elastic problems.