• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.195-199
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• 1998

본 논문은 감성측정평가 시뮬레이터 구축의 일환으로 개발한 3차원 시청각 환경 제시기가 생성하는 가상환경의 현실감 점도를 평가하는데 목적이 있다. 이를 위하여 가상환경의 최소 구성성분요소들로 Size, Length, Distance 등을 설정하였으며, 이들에 대하여 가상환경과 실제환경에서 각각 실험을 통해 피실험자들의 인식전도를 측정하였다. 실험에서 사용한 측정방법은 가상세계에 대한 인식실험을 위해 개발된 Size/Distance Estimation, Sketch Map, Object Search 방법 등을 사용하였으며, 가상환경과 실제환경에서 각각 도출된 실험결과의 차이를 토대로 3차원 시청각 환경 제시기의 현실감 수준을 평가하였다. 본 실험을 위해 구성한 피실험자의 집단은 컴퓨터 사용에 익숙한 20대 이공계열 84명(남:56, 여:28)의 학생들을 대상으로 하였다. 본 논문의 의의로는 3차원 시청각 환경 제시기가 생성하는 가상환경의 현실감 수준을 평가함으로써 개발 시스템의 보완 및 발전과 본격적인 감성공학 분야의 활용을 위한 지침을 마련하는데 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.457-461
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• 2010

소하천에서의 효율적인 유량측정 수행을 위해서 K-water(한국수자원공사) 충청지역본부에서는 금강유역의 보청천 지류인 곰쟁이천에 원격유량측정시설 개념의 위어(weir)를 이용한 고정단면 시설물을 2006년도에 설치하였으며, 2007년부터 2009년까지 시설물 직하류에서 도섭을 통한 유량측정을 실시하였고 3차원 흐름해석 결과와의 비교를 통해 소하천 원격유량측정시설의 적정성을 분석하였다. 총 55회의 유량측정 성과를 이용하여 수위-유량 관계곡선식을 산정하였으며, FLOW-3D를 이용하여 3차원 흐름해석을 실시하였다. Francis 유량산정 공식인 Q=$1.84bH^{3/2}$을 통해 계산되는 수위별 유량, 유량측정 성과에 의한 수위-유량 관계곡선식, 그리고 FLOW-3D로부터 계산된 수위별 유량을 비교하였으며, 실측유량과 계산된 유량의 차이를 비교 검토하였다. 이러한 비교 검토를 통해 소유량 구간에 대해서는 원격유량측정시설의 적정성을 확인할 수 있었으며, 갈수시 미소유량이 흐르는 소하천에 위치한 지점에 대해서는 인력 및 비용이 많이 소요되는 도섭을 통한 직접 유량측정 수행보다는 검증된 유량측정시설(위어, 파샬플룸 등)을 통한 유량측정이 더욱 효과적인 것으로 판단되었다.

• Journal of Broadcast Engineering
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• v.15 no.5
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• pp.607-616
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• 2010

The methods developed to measure visual fatigue so far are quite few and lack of validity, and more importantly, they do not figure out the complex properties of the visual fatigue. The purpose of the research was to analyze the factors comprising the visual fatigue and to develop the method to measure it validly. The results are summarized as follows. First, we found that the 3D visual fatigue was comprised of four independent factors (visual stress, eye pain, body pain and image blurring factors). Second, we developed 29 items that measure four factors of 3D visual fatigue. Finally, the watching duration and binocular disparities affected the visual fatigue as had been expected. These results imply that the developed method does measure the three dimensional fatigue validly.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.85.2-85.2
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• 2010

우리나라에는 조선 태조와 숙종대에 돌에 새겨 만든 두 개의 천상열차분야지도(天象列次分野之圖)가 남아 전하고 있다. 숙종본 천문도는 태조본을 다시 복각한 것으로 알려져 있으며 천문도의 구성은 태조본의 뒷면과 같은 모습이다. 국보 228호로 지정된 태조본 천문도는 오랜 시간의 흐름에 따른 표면 마모로 명문이나 별자리 확인이 쉽지 않다. 특히, 태조본 뒷면은 심한 훼손으로 별의 크기 뿐 아니라 대부분의 별자리 확인도 어려운 상황이다. 지금까지 천문도 표면의 훼손으로 인해 태조본의 앞 뒷면과 숙종본에 새겨진 별의 위치와 크기를 정량적으로 비교하기가 어려웠다. 본 연구에서는 숙종본 천문도의 별자리와 함께 태조본의 앞뒷면 천문도의 별의 위치 및 크기를 정량적으로 비교하기 위해 2008년과 2009년에 걸쳐 태조본 석각 천문도를 3차원 정밀 측정하였다. 천문도 측정은 삼각측량과 간섭효과를 활용한 3차원 스캐너인 Breukmann을 사용하였으며 0.1mm 이내의 측정 정밀도로 측정하였다. 3차원 정밀 측정 자료는 유물 훼손을 대비한 복원 자료구축, 복제품 제작을 위한 기초자료 그리고 별자리 연구를 위한 천문자료 등으로 활용할 수 있다. 우리는 3차원 측정을 통해 석각 천문도의 전체 형태뿐 아니라 모든 별의 위치와 크기의 측정 자료를 DB화 하였으며, 이를 이용해 태조본의 앞 뒷면과 숙종본에 새겨진 별의 위치와 크기를 비교하고 각각의 특성을 조사하였다. 또한 천문도에 새겨진 별의 크기와 실제 별의 밝기와의 상관관계를 알아보았다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.307-307
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• 2004

본 논문에서는 3차원 스캔기기에서 실제 모델을 측정하여 얻어지는 점 데이터로부터 모델의 표면을 생성하는 알고리즘을 제안한다. 3차원 스캔기기가 정밀해지고 스캔 규모도 커짐에 따라 측정 데이터의 크기도 증가되어, 이러한 대용량 측정 데이터의 복원 알고리즘이 필요로 되고 있다. 그리고 여러 다른 각도에서 스캔닝 된 점 데이터들은 이어지는 부분이 정확히 맞지 않아 중첩되어 표현되거나 기계적인 또는 환경적인 제약 등의 이유로 오류가 포함될 수도 있다. 그러므로 복원 알고리즘은 이러한 중첩된 표현을 정리하고 오류를 보정해 주어야 한다.(중략)

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.975-980
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• 2020

Cervical neural foraminal stenosis is a very common spinal disease that affects a relatively large number of people of all ages. However, since imaging methods that quantitatively provide neural foraminal stenosis are lacking, this study attempts to present quantitative measurement results by reconstructing 3D computed tomography images. Using a 3D reconstruction software, the surrounding bones were removed, including the spinous process, transverse process, and lamina of the cervical spine so that the neural foramen were well observed. Using Image J, a region of interest including the neural foramen area of the 3D image was set, and the number of pixels of the neural foramen area was measured. The neural foramen area was calculated by multiplying the number of measured pixels by the pixel size. In order to measure the widest area of the neural foramen, it was measured between 40-50 degrees in the opposite direction and 15-20 degrees toward the head. The measured cervical neural foramen area showed consistent measurement values. The largest measured area of the right neural foramen C5-6 was 12.21 ㎟, and after 2 years, the area was measured to be 9.95 ㎟, indicating that 18% stenosis had progressed. Since 3D reconstruction using axial CT scan images, no additional radiation exposure is required, and the area of stenosis can be objectively presented. In addition, it is good to explain to patients with neural stenosis while viewing 3D images, and it is considered a good method to be used in the evaluation of the progression of stenosis and post-operative evaluation.

• Therapeutic Science for Rehabilitation
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• v.12 no.1
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• pp.79-92
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• 2023

Objective : This study aimed to assess the reliability of a three-dimensional (3D) motion analysis program for measuring the range of motion (ROM) of wrist and finger joints. Methods : The study recruited 50 people who had no restrictions on wrist and finger movements, understood the purpose of this study, and agreed to participate. Using a goniometer and a 3D motion analysis program, a total of 11 wrist and finger ROM were measured once each. To measure the reliability of the 3D motion analysis program, the degree of agreement and inconsistency of the measured values were compared. Results : Analysis of the degree of agreement of the measured values revealed that 38 out of 44 items showed a very high degree of agreement. Regarding analysis of inconsistency in the measured values, inconsistencies were found in three items. Conclusion : The results of this study confirmed that the ROM of the joint could be measured using the 3D motion analysis program applied in this study. In addition, it might be expected that the 3D motion analysis program would be used in various clinical fields owing to the advantages of measurement convenience and accuracy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.35-39
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• 2019

The shielding effectiveness (SE) of the EMI spray coating film was measured in a three-dimensional structure. The shielding effectiveness was measured by AST D4935 using coaxial type TEM cell. A standard sample of the cylindrical slab is fabricated to measure the shielding effectiveness using the ASTM D4935. At this time, spray coating was performed by bonding a three-dimensional structure with NAND flash memory to a standard sample. In the case of spray coating, it was uniformly coated not only on the horizontal plane but also on the vertical plane of the three-dimensional structure. As a result of measurement, shielding effectiveness of maximum 59 dB was measured in a three-dimensional structure similar to the case without three-dimensional structure. As a result, it was confirmed that the spray coating can be uniformed even in the three-dimensional structure.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.1
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• pp.69-76
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• 1995

This study is the 3-D precision deformation measurement of a bridge, obtain results of precision control points by GPS and 3-D measurement system and develope efficientlty technices which can solve precision 3-D analysis by CRP In the result, we could overcome the problems of former control point measurement in the way of the combination system of GPS and 3-D measurement system to positioning decision of reference points and control points. Then we could symplify old measurement process on the 3-D deformation analysis of a linear structure and complement parted analysis fault of measurement instrument.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.2
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• pp.129-135
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• 2015

The objective grading system for the facial palsy is needed. In this study, the facial palsy grading system was developed with combination of three dimensional image processing and Nottingham scale. The developed system is composed of 4 parts; measurement part, image processing part, computational part, facial palsy evaluation & display part. Two web cam were used to get images. The 8 marker on face were recognized at image processing part. The absolute three dimensional positions of markers were calculated at computational part. Finally, Nottingham scale was calculated and displayed at facial palsy evaluation & display part. The effects of measurement method and position of subject on Nottingham scale were tested. The markers were measured with 2-dimension and 3-dimension. The subject was look at the camera with $0^{\circ}$ and $11^{\circ}$ rotation. The change of Scale was large in the case of $11^{\circ}$ rotation with 2-dimension measurement. So, the developed system with 3-dimension measurement is robust to the orientation change of subject. The developed system showed the robustness of grading error originated from subject posture.