• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1891-1898
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• 2013

To efficiently execute 3D graphic APIs, such as OpenGL and Direct3D, special purpose arithmetic unit(SFU) which supports floating-point sine, cosine, reciprocal, inverse square root, base-two exponential, and logarithmic operations is designed. The SFU uses second order minimax approximation method and lookup table method to satisfy both error less than 2 ulp(unit in the last place) and high speed operation. The designed circuit has about 2.3-ns delay time under 65nm CMOS standard cell library and consists of about 23,300 gates. Due to its maximum performance of 400 MFLOPS and high accuracy, it can be efficiently applicable to mobile 3D graphics application.

• Computers and Concrete
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• v.3 no.1
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• pp.29-42
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• 2006

In this study, a novel education system for inspection of concrete bridges is presented. The new education approach uses virtual reality (VR) and three-dimensional computer graphics (3DCG) in training engineers to become bridge inspection specialists. The slow time-dependent deterioration of concrete bridges can be reproduced on the computer screen in any chosen time frame, thus providing the trainees with illustrative and educative insight into the deterioration problem. In the proposed VR/3DCG approach a three-dimensional model of concrete bridge, including surfaces, viewpoints and walkthrough paths is created. With the help of this virtual bridge model, an experienced bridge inspection specialist teaches the different deterioration phenomena of concrete bridges to the trainees. The new system was tested, and the inspection results from the case bridge showed that in comparison with the traditional Japanese bridge inspection education system, the new system gives better results. In addition to the improvement of quality of bridge inspections, the new VR/3DCG system-based education brings along some other, more intangible benefits.

• Journal of the Korea Computer Graphics Society
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• v.22 no.3
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• pp.63-73
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• 2016

Animation contents are gradually growing every year, but production period and budget for making one animation contents is insufficient as of now. In particular, in case of animation series that are broadcasted on television, many episodes should be made within a short period of production term. Hence, production pipeline of full three-dimensional animation is frequently chosen in this case. However, another problem emerges as the full three-dimensional animation also requires a lot of time for making high-quality background and for rendering. Composed animation is a production pipeline that attempts to solve such problem. It is a pipeline of producing animation by composing computer graphic (CG) character and real background. It requires relatively small number of human resources compared to the full three-dimensional animation pipeline. Hence, it has an advantage in that natural-looking image can be produced under efficient structure and time for rendering can also be reduced. This paper proposes an efficient process of producing composed animation by using miniature set and three-dimensional computer graphic.

• ETRI Journal
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• v.41 no.3
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• pp.277-288
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• 2019

VWorld is run by the Ministry of Land, Infrastructure, and Transport of South Korea and provides national spatial information, such as aerial images, digital elevation models, and 3D structural models. We propose herein an open platform for 3D spatial information based on WebGL using spatial information from VWorld. WebGL is a web-based graphics library and has the advantage of being compatible with various web browsers. Our open platform is also compatible with various web browsers. Accordingly, it is easily accessible via the VWorld site and uses the three-dimensional (3D) map program. In this study, we describe the proposed platform configuration, and the requests, management, and visualization approaches for VWorld spatial information data. Our aim is to establish an approach that will provide a stable rendering speed even on a low-end personal computer without a graphics processing unit based on a quadtree structure. We expect that users will be able to visualize 3D spatial information through the VWorld open platform, and that the proposed platform will become the basis for various applications.

• Journal of the Korea Computer Graphics Society
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• v.29 no.3
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• pp.149-158
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• 2023

HMD, which is applied with the latest technology, minimizes motion sickness with high-resolution displays and fast motion recognition, and can accurately track location and motion. This can provide an environment where you can immerse yourself in a virtual three-dimensional space, and virtual reality contents such as disaster simulators and high-risk equipment learning spaces are developing using these characteristics. These advantages are also applicable in the field of basic science education. In particular, expanding the concepts of electric and magnetic fields in physics described by existing two-dimensional data into three-dimensional spaces and visualizing them in real time can greatly help improve learning understanding. In this paper, realistic physical education environments and contents based on three-dimensional virtual reality are developed and the developed learning contents are experienced by actual learning subjects to prove their effectiveness. A total of 46 middle school and college students were taught and experienced in real time the electric and magnetic fields expressed in three dimensions in a virtual reality environment. As a result of the survey, more than 85% of positive responses were obtained, and positive results were obtained that three-dimensional virtual space-based physical learning could be effectively applied.

• Journal of the Korea Computer Graphics Society
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• v.3 no.2
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• pp.77-84
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• 1997

Solid modeling refers to techniques for unambiguous representations of three- dimensional objects. The most widely used techniques for solid modeling have been Constructive Solid Geometry (CSG) and Boundary Representation (BRep). Contemporary solid modeling systems typically support both representations, and bilateral conversions between CSG and BRep are essential. However, computing a CSG from a BRep is largely an open problem. This paper presents 3D geometric reasoning algorithms for converting a BRep into a special CSG, called Destructive Solid Geometry (DSG) whose Boolean operations are all subtractions. The major application area of BRep-to-DSG conversion is feature recognition, which is essential for integrating CAD and CAM.

• Journal of Information Technology Applications and Management
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• v.19 no.1
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• pp.13-24
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• 2012

Usability and knowledge drawn from utilizing various ways of representing accounting data were examined. Classroom experiments were conducted to compare students' assessment of financial data using table of numbers, 2-dimensional column graphs (2D), 3-dimensional column graphs (3D), and mixed reality visualization of true 3-dimensional graphs (MR). The results showed that in assessing the financial status and performance of a firm, Table of numbers and MR took longer than 2D and 3D graphs. The time spent on true 3D graphs using MR technology was about the same as Table of numbers. When compared the assessment scores of the firm's financial status and performance between participants and experts, the difference was the least when participants used 2D graphs. However, MR was seen as being a new way to provide data of greater complexity and was very useful for financial information.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.544-551
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• 2000

A fabrication method of inner and outer crown using CAD/CAM is presented. The information of abutment teeth is transferred to a computer through a 3-dimensional scanner. A Konus inner and outer crown is designed on a computer and a real crown is machined based on this design using CAM. This method can save laboratory time and reduce inaccuracies compare to conventional casting procedure. A stone model with six prepared abutment teeth from a patient was used in this study. Three dimensional information from the model was transferred to a computer using a contact type 3-dimensional scanner with a $25{\mu}m$ accuracy. All margins were identified on a computer image where there is a change in surface taper of a model. To provide a cement space, the image of a inner sur face of a Konus inner crown was duplicated $25{\mu}m$ apart from the surface of a prepared abutment teeth image. The cement space was $20{\mu}m$ at the cervical margin. All Konus crowns were machined with a $10{\mu}m$ accuracy. It was concluded that this method can reduce working-time for the laboratory process and increase accuracy. A further research is required to make a simplified process for a more complex prosthesis.

• Journal of the Korea Computer Graphics Society
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• v.11 no.2
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• pp.34-39
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• 2005

본 논문에서는 인터넷 게임 개발에 있어서 배경 화면을 구성하는 3차원 가상환경 생성 및 가상환경을 돌아다니면서 주변을 관찰할 수 있게 하는 카메라 처리 기능을 포함한 가상환경 제어 방법에 대해 기술한다. 여기에 포함되는 기술로서 3차원 지형 메쉬 데이터 처리, 맵에디터, 장면 처리, 캐릭터의 충돌 처리 및 게임 제어 방법 등을 소개한다. 그리고, 시맨틱 가상환경 구현을 목적으로 가상환경상의 각 위치에 대해 의미를 부여할 수 있도록 현재 위치에 대한 정보 입력을 가능하게 해주는 위치 기반 동적 정보 입력기에 대해서도 설명한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.229-232
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• 2009

In this paper, we propose a new programmable shader architecture based on an effective ALU operation. Today's mobile devices need the programmable shader processor for a three-dimensional(3D) graphics. The programmable shader processors require a lager ALU than a fixed pipeline ALU used previously. The proposed ALU architecture is able to execute two different arithmetic operations at the same time. Two instructions which need exclusive ALU operations are inserted into instruction decoders in parallel. Experimental results show the number of instruction cycles can be substantially reduced up to 40%.