• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.104-115
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• 2018

Purpose: The purpose of this study is to evaluate the image acquisition ability of intraoral scanners by analyzing the comprehensiveness of scanned images from standardized model, and to identify problems of the model. Materials and Methods: Cast models and 3D-printed models were prepared according to international standards set by ISO12836 and ANSI/ADA no. 132, which were then scanned by model scanner and two different intraoral scanners (TRIOS3 and CS3500). The image acquisition performance of the scanners was classified into three grades, and the study was repeated with varying surface conditions of the models. Results: Model scanner produced the most accurate images in all models. Meanwhile, CS3500 showed good image reproducibility for angled structures and TRIOS3 showed good image reproducibility for rounded structures. As for model ingredients, improved plaster model best reproduced scan images regardless of the type of scanner used. When limited to 3D-printed model, powdered surface condition resulted in higher image quality. Conclusion: When scanning structures beyond FOV (field of view) in standardized models (following ISO12836 and ANSI/ADA 132), lack of reference points to help distinguish different faces confuses the scanning and matching process, resulting in inaccurate display of images. These results imply the need to develop a new standard model not confined to simple pattern repetition and symmetric structure.

• Journal of the Korea Computer Graphics Society
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• v.8 no.4
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• pp.1-7
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• 2002

This paper presents a new approach for modeling human limbs shape from 3D scan data. Based on the cylindrical structure of limbs, the overall shape is approximated with a set of ellipsoids through ellipsoid fitting and interpolation of fit-ellipsoids. Then, the smooth domain surface representing the coarse shape is generated as the envelope surface of ellipsoidal sweep, and the fine details are reconstructed by constructing parametric displacement function on the domain surface. For fast calculation, the envelope surface is approximated with ellipse sweep surface, and points on the reconstructed surface are mapped onto the corresponding ellipsoid. We demonstrate the effectiveness of our approach for skeleton-driven body deformation.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.644-646
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• 1999

본 논문은 한 물체에 대해 스캔 위치 정보가 없는 여러 시점의 레인지 이미지들로부터 3차원 형상 복원을 위한 정합 알고리즘을 제안한다. 기존의 정합 방법은 스캔 위치 정보와 기하학 정보를 이용하여 레인지 이미지들을 정렬시킨 반면, 본 논문의 정합 방법은 스캔 위치와는 독립적으로 수행되며 기하학 정보와 텍스쳐 정보를 함께 이용하여 정렬시킨다. 그러므로 텍스쳐가 있는 여러 장의 레인지 이미지들로부터 3차원 형상을 보다 정확하고 효율적으로 복원할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.519-521
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• 2011

본 연구는 3D 레이저 스캔 방법으로 계측된 인체 데이터를 대상으로 3D 아바타 애니메이션 모듈 구현을 목표로 한다. 이를 위하여 인체의 뼈 골격계 기준점을 지정한다. 기준점을 이용하여 계층에 맞는 골격을 잡아 오브젝트를 이루고 있는 정점들과 그에 해당되는 골격들을 연결하고 기구학에 의한 행동패턴을 제작하여 아바타에 애니메이션을 적용 시킨다. 이를 위하여Visual C++ OpenGL 라이브러리를 이용 하였고 인체 전신 레이저 스캔 데이터를 대상으로 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1448-1450
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• 2015

본 논문은 3D 스캐너 및 센서 등으로 캡처되어 3D로 복원된 얼굴 객체의 부위별 의미 있는 영역에 대한 분할을 자동으로 수행하는 기술을 제안한다. 3D 스캔된 얼굴 모델을 모델링, 애니메이션, 3D 프린팅 등의 다양한 응용분야에 활용하기 위해서는 스캔된 영역의 의미 있는 부위별 인식이 필수적이다. 본 논문에서는 부위별 의미 있는 영역 레이블링이 된 템플릿 모델을 입력된 3D 복원 모델로 전이하여 복원된 3D 모델의 부위별 의미 있는 영역을 자동으로 분할하고 분할된 영역의 일관성을 유지하는 알고리즘을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.2023-2030
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• 2010

In this paper, we present research results of developing high performance scan conversion unit and implementing it on FPGA chip. To increase performance of scan conversion unit, we propose an architecture of scan converter that is a SIMD architecture and uses tile-based traversing method. The proposed scan conversion unit can operate about 124Mhz clock frequency on Xilinx Vertex4 LX100 device. To verify the scan conversion unit, we also develop shader unit, texture mapping unit and $240{\times}320$ color TFT-LCD controller to display outputs of the scan conversion unit on TFT-LCD. Because the scan conversion unit implemented on FPGA has 311Mpixels/sec pixel rate, it is applicable to desktop pc's 3d graphics system as well as mobile 3d graphics system needing high pixel rates.

• Journal of KIBIM
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• v.6 no.4
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• pp.18-26
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• 2016

Recently, for the purpose of maintenance of facilities and energy, there have been growing cases of the 3D image scan-based reverse design technology mostly in the manufacturing field. In the MEP field, because of differences between design and physical model, the reverse technology has been utilized in factory facilities such as a semiconductor factory. Because 3D point clouds from scanning include accurate 3D object information, the efficiency of management works related to the complex MEP facilities can be enhanced. In this study, the reverse technology was surveyed, and the MEP facility management based on 3D image scanning was analyzed. Based on the results, a method of 3D image scan-based MEP facility management was proposed.

• Smart Media Journal
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• v.12 no.9
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• pp.134-141
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• 2023

In this paper, we propose a ToF-Stereo fusion sensor system for 3D space scanning that increases the recognition rate of 3D objects, guarantees object detection quality, and is robust to the environment. The ToF-Stereo sensor fusion system uses a method of fusing the sensing values of the ToF sensor and the Stereo RGB sensor, and even if one sensor does not operate, the other sensor can be used to continuously detect an object. Since the quality of the ToF sensor and the Stereo RGB sensor varies depending on the sensing distance, sensing resolution, light reflectivity, and illuminance, a module that can adjust the function of the sensor based on reliability estimation is placed. The ToF-Stereo sensor fusion system combines the sensing values of the ToF sensor and the Stereo RGB sensor, estimates the reliability, and adjusts the function of the sensor according to the reliability to fuse the two sensing values, thereby improving the quality of the 3D space scan.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.413-420
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• 2003

In this paper, the correction method of antenna beam direction errors is introduced which caused by frequency scan effect in active Phased may antenna for satellite communications. The antenna makes the beam directional error from frequency scan effect when it has dual beam may structure with asymmetrical series connection, their frequencies are different and for from each other, their 3dB beamwidth is narrow, and scan range is wide. By proposed equations, estimated beam direction error angles can be calculated and active phase shifter control values also can be calculated to compensate them. In this paper, the active phased array antenna system was fabricated to measure beam direction errors both before and after correction, which has dual beam from 32${\times}$4 main level array and 4${\times}$2 second level array, frequency deviation 500 MHz max.(6.7 %) at 7.25 GHz∼7.75 GHz ranges, 0$^{\circ}$∼${\pm}$35$^{\circ}$nm ranges, and 35.6 dBi gain with 2.2$^{\circ}$3 dB beam width. Its beam direction error by frequency san effect which was 2.5$^{\circ}$max., was reduced to 0.2$^{\circ}$max. after correction. This was 7 dB improvement of signal loss. The active phased array antenna can accurately track the target satellite for communications by this proposed correction method.

• Journal of the Korea Fashion and Costume Design Association
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• v.22 no.1
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• pp.1-13
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• 2020

The purpose of this study is to create a 3D avatar from 3D human body shape data using the CLO 3D virtual clothing program and to verify the feasibility of avatar production using the virtual clothing system for verifying size and shape. The research method was to select one virtual representative model that is the closest to the mean size of each body item for each age group. Using the 3D human body scan shape of a 40-69 years old male was applied to the CLO 3D virtual wearing system. Using the CLO 3D Avatar conversion menu, we verified the feasibility of creating a 3D avatar that reproduces the human body scan shape. In the dimension comparison between the 3D avatar and the fictitious representative model, the dimension difference was noticeable in height, circumference, and length. However, as a result, the converted 3D avatar showed less than a 5% difference in most human dimensions. In addition, since the body shape and posture were reproduced similarly, the utilization of the avatar was verified.