• Proceedings of the IEEK Conference
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• summer
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• pp.361-364
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• 2004

This paper describes an automatic 3D models generation algorithm based on 2D silhouette images, using X-ray camera without camera parameters. The algorithm takes a multi steps process approach. First, a series of 2D silhouette images is captured from different directions of object and then converted to binary images. An octree data structure is constructed for voxel-based representation of object. An estimate 3D volume of object can be reconstructed by intersecting voxels and the 2D silhouettes. The marching cube algorithm is applied to get triangle mesh representing of the obtained 3D model for rendering.

• Architectural research
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• v.15 no.2
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• pp.103-109
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• 2013

Various types of building information should be linked to 3D model objects for their effective use by stakeholders. Because Building Information Modeling (BIM) based on 3D is used by different stakeholders, the created BIM need standard guidelines for each purpose, as, for example, for quantity take-off. Thus, this study was conducted to propose guidelines for BIM modeling for quantity take-off in the framework, especially, in the concrete and form. The proposed guidelines adopted each element of the BIM model based on an analysis of the problem of the general BIM model. Moreover, the usability and accuracy of the reinforced structure modeling guidelines were verified by comparing the quantity of the commercial estimation software and the modeling quantity using the proposed modeling guidelines.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.91-101
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• 2011

This research aims to suggest web-based 3D face modeling system for hairline modification surgery. As public interests in beauty regarding face escalate with era of wide persoanl mobile smart iCT devices, need for medical information system is urgent and increasing demand. This research attempted to build 3D facing modeling library deploying conventional technology and proprietary software available. Implications from the our experiment found that problems and requirement for developing new web based standard. We suggest new system from our experiment and literature review regarding relevant technologies. Main features of our suggested systems is based on studies regarding hair loss treatment such as medical science, beauty studies and information technology. This system processes input images of 2D frontal and profile pictures of face into 3D face modeling with mesh-data. The mesh data is compatible with web standard technology including SVG and Canvas Tag supported natively by HTML5.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.184-191
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• 2020

Avionics System Integration Laboratory is the integrated test environment for integration and verification of avionics systems. When real equipment can not be used in the laboratory for various reasons, software models should be needed. Because there hasn't been any standardized method for the models so that it is difficult to reuse the developed models, the need for a framework to develop the avionics software models was emerged. We adopted DEVS(discrete event system specification) formalism as the standardized modeling method for the avionics software models. Due to DEVS formalism is based on event-driven algorithm, it doesn't accord a legacy system which has sequential and periodic algorithms. In this paper, we propose real-time event-driven modeling and simulation method for SIL to overcome these restrictions and to maximize reusability of avionics models through the analysis of the characteristics and the limitations of avionics models.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.452-459
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• 2015

Thanks to the development of applications, many people are using a smart phone cradle these days. But it has some problems. First of all, it is hard to fix on automobiles. Also, it is vulnerable to external vibration. Recognizing these problems, we decided to improve this device by using FreeCAD and ANSYS. Because FreeCAD is newly invented software, we used another 3D modeling software to cover shortages of tools in FreeCAD. Also, we used famous analysis software 'ANSYS' to analyze bending deformation, modal analysis, and harmonic analysis.

• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.177-189
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• 2013

3D modeling and rendering technologies are getting more attention from landscape planners and architects because the virtual reality based on 3D graphic technology could give more realistic experience to landscape simulation users and boost promotional effects. The 3D landscape simulation, however, not only requires a lot of cost and time in production, but also demands efforts to distribute to consumers due to various computing environment of them. The purpose of this study is to suggest a process for developing an interactive 3D landscape simulator with low-cost, which can support multi-platform functionality in high quality through reviewing related current software and web services. We select GIMP for 2D image texturing, SketchUpfor 3D modeling, Unity for real-time rendering, and Google Earth for terrain modeling considering price and workability and apply the developed process for Windows, Web, and Android versions to test the applicability for Sangji-ri, Gosam-myeon, Gyeonggi-do, Korea.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.632-638
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• 2002

Extensible 3D(X3D) is a software standard for defining interactive web and broadcast-based 3D content integrated with multimedia. The data size of Web3D representation based on polygon meshes is so large that transferring practical data fast is a hard problem. This paper proposes 3D object structure, a new framework for compact 3D representation with high quality surface shape. By utilizing a free form surface technique, qualified surface are transferred with limited amount of data size and rendered. 3D graphic structure can be regarded ad both polygon meshes and free form surfaces. Therefore, it can be easily integrated to existing Web3D data formats, for example VRML ＆ XML. 3D object structure also enables modeling free form surface shapes intuitively with polygon modeling like operations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.984-990
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• 2017

Mesh screen modeling and liquid propellant discharge simulation of surface tension tank were performed using commercial CFD software Flow-3d. $350{\times}2600$, $400{\times}3000$ and $510{\times}3600$ DTW mesh screen were modeled using macroscopic porous media model. Porosity, capillary pressure, and drag coefficient were assigned for each mesh screen model, and bubble point simulations were performed. The mesh screen model was validated with the experimental data. Based on the screen modeling, liquid propellant discharge simulation from PMD tank was performed. NTO was assigned as the liquid propellant, and void was set to flow into the tank inlet to achieve an initial volume flow rate of liquid propellant in $3{\times}10^{-3}g$ acceleration condition. The intial flow pressure drop through the mesh screen was approximately 270 Pa, and the pressure drop increased with time. Liquid propellant discharge was sustained until the flow pressure drop reached approximately 630 Pa, which was near the estimated bubble point value of the screen model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3284-3306
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• 2018

This study proposes a method to develop an authoring system(GeoMaTree) for diverse trees that constitute a virtual landscape. The GeoMaTree system enables the simple, intuitive production of an efficient structure, and supports real-time processing. The core of the proposed system is a procedural modeling based on a mathematical model and an application that supports digital content creation on diverse platforms. The procedural modeling allows users to control the complex pattern of branch propagation through an intuitive process. The application is a multi-resolution 3D model that supports appropriate optimization for a tree structure. The application and a compatible function, with commercial tools for supporting the creation of realistic synthetic images and virtual landscapes, are implemented, and the proposed system is applied to a variety of 3D image content.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5243-5250
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• 2013

BIM(Building Information Modeling) enables 3D model-base management for all information produced by construction project during its life cycle. Also as a national policy, BIM has been institutionalized as design criteria. But, on the matter of 2D drawing using BIM software (Revit Architecture), it has been recognized as difficult to realize the same quality drawing drawn by CAD. The purpose of this study is verifying the possibility of printable design drawing implemented by BIM software at the same quality of 2D shop drawing drawn by 2D CAD. Through the analysis of basic design elements of 3D BIM software and 2D CAD software, with the case of partial cross sectional drawing which is most faithful representation of the basic design elements, this study find out that the 3D BIM software can produce the same quality 2D printable drawing utilizing its implicit function.