• Journal of Digital Contents Society
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• v.13 no.3
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• pp.459-467
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• 2012

In this work, we develop an instructional method in which students create 3D animations based on problem-solving techniques and computational thinking. The educational, easy-to-learn programming environment/language called "Alice 2.3", which supports story-telling, is used for the delivery of the instructional method. Unlike typical 3D animation instructional methods using command-based demonstrations and/or 3D animation tools, learners engage in a group project in which they develop a story and solve problems by creativity, computational thinking and reasoning skills. Then they develop animations based on the story by programming with Alice. The analysis based on the collected data showed that learners had to put much effort while working on the project, but their critical-thinking skills were improved. It also showed they were more involved and their interests were heightened in developing animation through programming.

• IE interfaces
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• v.9 no.2
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• pp.129-141
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• 1996

Recently, the tire mold of a passenger car is made almost via aluminum casting, and it is necessary to prepare a master model of the tire for the casting. Because of the geometrical feature of tire, as well known, the master model must be machined by a 5-axis NC machine. The paper proposes a procedure to model and machine the master model. The approach includes (a) transformation of 2D drawing of tire into 3D geometry, (b) modeling surfaces of tire, and (c) inverse kinematics of a 5-axis NC machine. An implementation of the proposed procedure is also presented.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.460-460
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• 2006

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.57-59
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• 2000

실세계의 객체들은 공간 정보뿐만 아니라 시간적 정보와도 연관을 갖는데 기존의 공간데이터베이스만으로는 시간 흐름에 따른 공간 객체의 정보를 효율적으로 관리해 주지 못하는 단점이 있다. 이러한 문제점을 해결하기 위하여 시공간 데이터베이스에 대한 데이터 모델과 시공간 연산자가 제시되었다. 그러나, 시공간 연산자에 대한 정의와 시그너처정도 만이 기술되었고 시공간 연산자에 대한 설계와 구현에 대한 사항은 제시되지 않았다. 이 논문에서는 시공간 데이터모델과 시공간 연산자 그리고 공간 연산자 구현 기법인 Planc-Sweep 기법을 이용한 시공간 연산자인 Trajectory와 MPIntersection에 대한 설계와 구현 알고리즘을 제시하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.85-87
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• 2006

자바의 특징 중 코드 재사용성을 강조하여 게임 엔진에서의 코드 재사용과 확장성을 고려한 비행기 전투 게임인 메타버스 게임 엔진을 개발한다. 현재 PC 게임 개발은 C/C++과 DirectX를 사용한 게임 개발을 주로 하고 있다. 제한된 개발 언어의 사용은 게임 엔진 제작에 있어 게임엔진의 다양화를 억제하는 요소가 된다.

• ETRI Journal
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• v.25 no.1
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• pp.19-24
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• 2003

This paper describes the performance of a Ku-band 5-bit monolithic phase shifter with metal semiconductor field effect transistor (MESFET) switches and the implementation of a ceramic packaged phase shifter for phase array antennas. Using compensation resistors reduced the insertion loss variation of the phase shifter. Measurement of the 5-bit phase shifter with a monolithic microwave integrated circuit demonstrated a phase error of less than $7.5{\circ}$ root-mean-square (RMS) and an insertion loss variation of less than 0.9 dB RMS for 13 to 15 GHz. For all 32 states of the developed 5-bit phase shifter, the insertion losses were $8.2{\pm}1.4$dB, the input return losses were higher than 7.7 dB, and the output return losses were higher than 6.8 dB for 13 to 15 GHz. The chip size of the 5- bit monolithic phase shifter with a digital circuit for controlling all five bits was 2.35 mm ${\times}$1.65 mm. The packaged phase shifter demonstrated a phase error of less than $11.3{\circ}$ RMS, measured insertion losses of 12.2 ${\pm}$2.2 dB, and an insertion loss variation of 1.0 dB RMS for 13 to 15 GHz. For all 32 states, the input return losses were higher than 5.0 dB and the output return losses were higher than 6.2 dB for 13 to 15 GHz. The size of the packaged phase shifter was 7.20 mm${\times}$ 6.20 mm.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.497-505
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• 2016

The two-dimensional (2D) Discrete Cosine Transform (DCT) is used widely in image and video processing systems. The perception of human visualization permits us to design approximate rather than exact DCT. In this paper, we propose a digital implementation of 16-point approximate 2D DCT architecture based on one-dimensional (1D) DCT and Modified Gate Diffusion Input (MGDI) technique. The 8-point 1D Approximate DCT architecture requires only 12 additions for realization in digital VLSI. Additions can be performed using the proposed 8 transistor (8T) MGDI Full Adder which reduces 2 transistors than the existing 10 transistor (10T) MGDI Full Adder. The Approximate MGDI 2D DCT using 8T MGDI Full adders is simulated in Tanner SPICE for $0.18{\mu}m$ CMOS process technology at 100MHZ.The simulation result shows that 13.9% of area and 15.08 % of power is reduced in the 8-point approximate 2D DCT, 10.63 % of area and 15.48% of power is reduced in case of 16-point approximate 2D DCT using 8 Transistor MGDI Full Adder than 10 Transistor MGDI Full Adder. The proposed architecture enhances results in terms of hardware complexity, regularity and modularity with a little compromise in accuracy.

• Journal of Korea Multimedia Society
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• v.5 no.2
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• pp.222-230
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• 2002

Various virtual reality methods are examined on the internet. In this paper, 3D implementations on the internet are discussed using Java3D and GL4Java which are based on the Java. 3D shoppingmall, real time 3D renderings, and various objects are implemented using Java3D and GL4Java, respectively. Especially with Java3D, the file formats of VRML97, OBJ, and 3DS are implemented using Java3D loader, which shows that object implementation in Java3D is better than other methods. Also, the comparisons between Java3D and GL4Java are discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.611-619
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• 2008

2.5D Mapping system that embody in this paper can make new design by doing draping to live various texture and model picture image of fashion clothes by pattern, and can confirm clothes work to simulation without producing direction sample or product directly. Also, the system can support function that can forecast fabric design and state of end article exactly, and the system can bring competitive power elevation of fashion industry and cost-cutting effect by doing draping using database of fabric and model picture image. 2.5D Mapping system composed and embodied by mesh warp algorithm module, light and shade extraction and application module, mapping path extraction module, mesh creation and transformation module, and 2.5D mapping module for more natural draping. Future work plans to study 3D fashion design system that graft together 3D clothes technology and 3D human body embodiment technology to do based on embodiment technology of 2.5D mapping system and overcomes expression limit of 2.5D mapping technology.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.560-563
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• 2008

The early web technology was 2D type and exchange of information was passive generally. AS the time had passed, users wanted to participate in the 3D environment which is similar to real world actively. However VRML which is expected to bring big changes of the web environment has not been expanded owing to various circumstances. At a recent Web 2.0 is the most popular topic in the Internet business. Basic concept of Web 2.0 is implementation of comfortable UI(User Interface) and implementation of more active web than previous web. Concept of RIA(Rich Internet Application) is one of the Web 2.0 important technologies. In this paper, we designed and implemented Web Environmental Sensor Data System which has fantastic UI and various functions by using Flex.