• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.616-619
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• 2002

The z-map structure is widely used for NC tool path verification as it is very simple and fast in calculation of Boolean operations. However, if the number of the x-y grid points in a z-map is increased to enhance its accuracy, the computation time for NC verification increases rapidly. To reduce this computation time, we proposed a NC verification method using 3-D graphic acceleration hardwares. In this method, the z-map of the resultant workpiece machined by a NC program is obtained by rendering tool swept volumes along tool pathos and reading the depth buffer of the graphic card. The experimental results show that this hardware-based method is faster than the conventional software-based method.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.49-49
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• 2009

Phosphors with oxide host material, YAG:$Ce^{3+}$ and $(Ca,Sr,Ba)_2SiO_4:Eu^{2+}$ yellow phosphor, has been used for LED applications. The WLEDs using these phosphors are widely used for LCD backlighting, automobile, and general lighting applications since they have high conversion efficiency and good thermal and chemical stability which can meet necessary life time of LED products up to now. With advances of LED chip technology, the external quantum efficiency and driving current in chip get higher so that the phosphors for high power chip are required to maintain high conversion efficiency and stability at high temperature due to the heat dissipated from LED chips. In addition, higher color rendering index of LED lighting and color reproducibility of LCD than those of LEDs with single yellow phosphors are required. In order to overcome these technical issues rising from evolution of LED technology, new phosphors are in demand and nitride phosphors, one of the promising new candidate materials, will be discussed here.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.486-489
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• 2016

가상현실 기반 훈련시스템은 3D 모델링 기법으로 개발되어 실시간 렌더링(Realtime Rendering)되는 훈련용 콘텐츠와 운동감 제공을 위한 모션플랫폼, 촉감 제공을 위한 햅틱장치 등 다양한 하드웨어를 이용하여 인간 감각에 대한 모의 체험환경을 제공함으로써 높은 훈련 몰입감을 제공한다. 훈련시스템의 구성요소 중 하드웨어들은 설계 성능을 바탕으로 정량적 시험평가로서 검증(Verification)과 확인(Validation)이 가능하나, 훈련환경에 대한 사실적 가시화가 요구되는 훈련용 콘텐츠는 시현을 위한 실시간 렌더링 성능 등의 정량적 시험평가 만으로 검증과 확인에 어려움이 많다. 본 연구에서는 일반 소프트웨어와 콘텐츠 소프트웨어 테스팅 요소 차이와 상용게임 콘텐츠와 훈련용 콘텐츠의 차이점을 분석하고, 훈련용 콘텐츠의 정량적 시험평가를 위한 명세서의 작성과 활용을 제안한다.

• Korean Journal of Computational Design and Engineering
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• v.11 no.6
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• pp.403-411
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• 2006

NURBS surfaces have been widely used in engineering design since it can create a smooth surface using minimal numbers of data. But deformation of the surfaces is quite difficult especially for the detailed modification. Also, NURBS surface deformation processes need many inputs, and it is not easy to be implemented in 3D virtual system. In this paper, both the surface trimming and multi-resolution surface are used for the detailed sculpting including sharp edges of NURBS surface. QuadTree is used to separate cleanly the target surface with the surface for sculpting effect. Simple user strokes are also used for the sculpting target curves and GOMS(Goals, Operators, Methods, Selection Rules) model is applied to verify the efficiency of the proposed sculpting process.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.11
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• pp.724-729
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• 1999

We developed the correlated color temperature (CCT) control technique for electrodeless sulfur lamp (ESL) by adding a few milligrams of NaI into sulfur discharge bulb. Nal produces intense Na D-line that changes the CCT of the ESL. We can adjustthe CCT in the range of 8,400 K to 3,600 K. Color rendering index can be maintained between 79 and 90 for the adjustable range of the CCT. the NaI helps the ESL dischargeable at below 0.5 kW of forward microwave power into the bulb. We have shown that this technique did not cause reduction of luminance compared to electrodeless elemental sulfur lamp.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.67-71
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• 2002

In this paper, we propose a new deformable model based on non-linear elasticity, anisotropic behavior and the finite element method and developed the high-speed controller for haptic control. The proposed controller is based on the PCI/FPGA technology, which can calculate the real position and transmit the force data to device rapidly, The haptic system is composed of 6DOF force display device, high-speed controller and HIR library for 3D graphic deformation algorithm & haptic rendering algorithm. The developed system will be used on constructing the dynamical virtual environment. we demonstrate the relevance of this approach for the real-time simulating deformations of elastic objects. To show the efficiency of our system, we designed simulation program of force-reflecting, As the result of the experiment, we found that the controller has much higher resolution than some other controllers.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.712-714
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• 2005

Real-time 3D visualization of large datasets imposes a distributed architecture of the rendering system and dedicated hardware for image composition. Previous work on this domain has relied on prohibitively expensive cluster systems with hardware composition done by complicated schemes. In this paper we propose a low-cost hardware compositor fur a high performance visualization cluster. We show the system's design and the results obtained using Simulink [1] for our image composition scheme.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3089-3091
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• 1999

To control IWR-III Biped Waking Robot, those complex modules are necessary that concurrent control multi-axes servo motors, PID & Feedforward gain tuning, initial value calibration, display current status of system, user interface for emergency safety and three-dimensional rendering graphic visualization. It is developed for various-type gait $data^{[1]}$ and for control modes (i.e open/closed loop and pulse/velocity/torque control) that Integrated Control Enviroment with GUI( Graphic User Interface) consist of time-buffered control part using MMC (Multi-Motion Controller) and 3D simulation part using DirectX graphic library.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.51-52
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• 2018

사실감 있는 디지털 캐릭터를 만드는 것은 3D 영역에서 가장 어려운 도전 중에 하나이다. 특히 얼굴의 특징을 만들기 어렵기 때문에 얼굴포착기술이 점점 보편화되어가고 있다. 본문에서도 Photo Scan의 얼굴포착으로 고품질의 디지털 캐릭터 모델을 얻는 방법을 제시하였다. 이 방법은 시간을 단축시킬 수 있을 뿐 아니라 효율이 높아서 이 작업 과정이 고품질의 디지털 캐릭터 모델을 얻는 데 매우 유용하다.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.301-303
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• 1996

A platform is developed for fast and effective functional mapping of human brain, which can allow semi-automatically the whole processes of an image segmentation, a fusion of MR and PET images, and 3-D rendering of volumetric data, including DICOM-based image transfers from PACS archiver within a short period of time.