Stress Field of Structures with Internal Cracks by 3D-ILC Technology: Experimental and Numerical Analysis

Haijun Wang,Haitang Qi,Xuhua Ren,Lei Tang,Qianqian Dong 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.1

Great achievements have been made regarding the stress field in the two-dimensional state, however the study of three-dimensional stress field visualization has still not been comprehensively examined. The model with internal cracks was prepared by the laser-medium interaction (3D-ILC), and with the aid of the photoelastic test technology, it visually showed the distribution characteristics of the stress field inside the rock with defects under the three-point bending test method. Primarily, based on the two-dimensional and three-dimensional stress optics law, the isometric fringes were converted into phase differences or optical path differences to visualize the stress field. Moreover, transparent glass, which had better transparency and brittleness closer to real rock was selected as the specimen material. Internal cracks changed the stress fringe distribution of the specimen, and the combination of 3D-ILC technology and photoelasticity provided a new way to visualize the three-dimensional stress field of brittle materials with internal cracks. Through the secondary development and utilization of ABAQUS finite element analysis software, the internal stress fields of brittle solid materials with horizontal internal cracks were visualized. Accurate characterization of the three-dimensional stress field of brittle solid materials has been a long-term goal pursued by researchers in the field of fracture, and it is also the basis and key to solving many practical engineering problems such as design, safety analysis and evaluation.

3D 입체 애니메이션 제작을 위한 효과적인 입체감 표현 연구

김정현(Jung Hyun Kim) 한국애니메이션학회 2011 애니메이션연구 Vol.7 No.4

3D 입체는 양안시차의 원리와 심리적 지각요인이 결합되어 실재감을 재현하는 것으로 제작하는 기술은 크게 어려운 것이 아니다. 다만 현재의 입체는 완벽하게 3차원 공간을 표현하지 못하기에 관객에게 시각피로를 유발할 수 있다. 그렇기 때문에 입체영상의 근본적인 한계를 벗어나 시각피로를 유발하지 않는 범위 내에서 풍부한 입체감을 표현할 수 있어야 한다. 국내에서도 영화 <아바타>개봉 이후, 3D 입체영상의 고부가가치에 대한 관심이 커지면서 두 편의 상업영화와 극장용 애니메이션이 제작되어 큰 관심을 모았다. 하지만, 화제성에 비해 흥행면에서 실패하고 말았다. 이것은 3D 입체영상을 제작할 수 있는 인력과 기술 등의 기초 인프라가 취약한 상태에서 입체 콘텐츠가 제작된 것이 문제라고 할 수 있다. 또한 입체에 대한 선행연구들이 양안시차 구현 및 입체 디스플레이 등과 같은 원천적 기술 부분에 초점이 맞추어져 있어 실질적인 3D 입체 애니메이션 제작에 필요한 다양한 자료 및 연구가 미흡하거나 부족한 실정이다. 이러한 상황에서 3D 입체 애니메이션을 제작하기 보다는 장기적 방안으로 국내 입체 애니메이션 산업의 발전과 인프라 구축을 위해서 다양한 연구에 의한 자료축적이 우선시 되어야 한다. 따라서 본 논문은 3D 입체 애니메이션 제작을 위한 자료로 활용되고자 양안시차의 한계성을 넘어선 효과적인 입체감 표현을 위해 심리적 요인으로 작용하는 시각 요소에 대해서 연구하여, 실제 어떻게 표현되는지 Anagl yph 방식의 입체이미지를 제작하고 분석하였다. 그리고 분석된 시각요소를 토대로 해외 3D 입체 애니메이션에서 어떻게 활용되었는지 확인하였다. 3-dimensional structure is to reproduce a sense of reality by combining the principle of binocular disparity and a psychological perceptual factor and the technology of producing it is not that difficult. But since the current three-dimensional structure does not represent three-dimensional space perfectly, it can cause visual fatigue of audience. Therefore, abundant three dimensional effect should be able to be expressed within the range that does not cause visual fatigue beyond the fundamental limits of stereopsis. Also in Korea, as interests grow for high added value of 3D stereopsis after the movie <Avatar> release, two commercial films and theatrical animation were made and attracted great interest. However, they were a box office failure compared to their topicality. The problem can be said that three-dimensional contents were made in the state that basic infrastructure such as manpower and technology etc. which can produce 3D stereopsis is vulnerable Also, since the previous studies on 3-dimensional structure have focused on the original technology part such as implementation of binocular disparity and three-dimensional display etc., a variety of resources and research required to produce substantial 3D stereoscopic animation are insufficient or not enough. In this situation, rather than creating 3D stereoscopic animation, data accumulation by a variety of studies should be prioritized in order to build infrastructure and develop domestic 3D animation industry as a long-term plan. Therefore, to be used as the data for making 3D stereoscopic animation, this thesis produced and analyzed the stereoscopic image of the Anaglyph method how it is expressed actually by studying the visual elements serving as the psychological factors for effective three-dimensional representation beyond the limitation of binocular disparity. And analyzed on the basis of visual elements from abroad 3D stereoscopic animation make sure that I was utilizing.

Three-dimensional Visualization and Interpretation of Pre- and Post-earthquake Data of 2017 Pohang Earthquake

( Jai-yong Park ),( Jiyeon Kim ),( Chandong Chang ),( Jeong-ung Woo ),( Junkee Rhie ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

We analyze pre- and post-mainshock earthquake data of the 2017 Mw 5.5 Pohang earthquake, South Korea to visualize the geometry of subsurface seismogenic faults and understandearthquake mechanisms. We use a total of 53 high-quality earthquake focal mechanism data from pre-mainshock earthquakes, which were triggered by hydraulic fracturing at the Pohang EGS (Enhanced Geothermal System) site, and 202 post-earthquake data, which are aftershocks of the Pohang earthquake. In order to perform three-dimensional visualization, we determine fault planes from the two nodal planes in individual focal mechanism solutions using the fault instability criterion under a given stress states. The sizes of individual fault planes are also scaled based on earthquake magnitudes. We carefully construct plausible fault planes by grouping individual fault planes based on their geometry and location to visualize them three-dimensionally as hexahedral elements. We then interpret how water injection through geothermal wells stimulated the faults.

3차원 렌더링 기술을 이용한 청동거울의 표면형상 가시화 및 분석

권다경 ( Da Kyung Kwon ),조영훈 ( Young Hoon Jo ) 공주대학교 문화재보존과학연구소 2019 문화재과학기술 Vol.14 No.1

이 연구에서는 문화유산의 문양, 명문, 제작흔, 보존상태 등에 대한 선행 가시화 방법의 한계를 보완하기 위해 청동거울 황비창천명경을 대상으로 3차원 스캐닝과 컴퓨터 그래픽 기반의 렌더링 기술을 적용하였다. 전체적인 연구는 3차원 고정밀 스캐닝 및 모델링, 가시화 렌더링 기술 적용, 형상분석 순으로 진행하였다. 가시화 렌더링 결과, 노말맵은 표면 요철과 문양 윤곽을 명확하게 나타냈고, 곡률맵은 유물 표면에 고착된 부식물을 가시화하였다. 앰비언트 오클루 전맵은 수중짐승과 사람형상 등의 미세 문양을 매우 잘 드러냈으며, 래디언스 스케일링맵은 청동거울 표면형상의 질감과 재질을 가시화하는 데 효과적이었다. 이처럼 3차원 스캐닝 기반의 렌더링 기술은 문화유산의 제작기법과 보존현황을 파악하고 해석하는데 최적의 디지털기술이다. 현재도 다양한 영상기술이 개발되는 만큼 문화유산에 지속적으로 활용될 수 있을 것으로 판단된다. In this study, three-dimensional scanning and computer graphic-based rendering technologies were applied on a bronze mirror inscribed with Hwangbichangcheon in order to supplement the limitation of preceding visualization methods regarding patterns, inscription, making traces, and conservation conditions of cultural heritages. The overall study was carried out in a sequence of three-dimensional high-precision scanning and modeling, visualization rendering technology application, and shape analysis. As a result of the visualization rendering, the normal map had clearly indicated its surface roughness as well as the pattern outline, and the curvature map had visualized the corrosion attached on the surface of the artifact. The ambient occlusion map had well revealed the fine patterns such as underwater beasts and human figures, and the radiance scaling map was effective in visualizing the surface form texture and materials of the bronze mirror. As such, 3D scanning-based rendering technology is a digital technology optimized to identify and interpret the patterns, making traces, inscriptions, and conservation conditions. With various imaging technologies being developed currently as well, it is expected to have a continuous utilization in cultural heritages.

시설거주 시각장애 아동의 또래관계에 대한 입체조형중심 미술치료 사례연구

김상분,김정애 사)한국아동발달지원연구소 2019 임상미술심리연구 Vol.9 No.1

The purpose of the study is to find out how to affect the relationship of peer related relationships when performing three-dimensional formative activity arts therapy for children with visual impairment in institutional settings. The subjects are two visually handicapped children residing in the Y institution. The study conducted a total of 24 sessions for 50 minutes from once or twice a week. Data processing for the results was observed and analyzed for each session of art therapy works and progress and pre-, mid, post- of interviews with the rehabilitation instructors and parents as well as pre- and post- of peer relationship examination developed by Hudson (1987) were conducted as the additional supplementary tools. The results of this study is as follows. Firstly, in the session analysis, there were many negative expressions during the early and mid-early in the art therapy. However, since the last term, here has been an increase in voluntary interaction, increasing attitudes and languages were cooperate with each other. Secondly, it has been observed positive behavior and attitude from the interviews which conducted the rehabilitation instructors and parents. Thirdly, as results of peer relationship examination was shown that post test which was higher than that of the prior test. From the results, this study shows that children with visual impairments can express their thoughts and feelings through their own figurative works and it was found that the three-dimensional formative activity itself works effectively as a means of communicating with others. Therefore, the study is meaningful to show the case model that has confirm some aspect in the art therapy of three-dimensional formative activity at improving peer relationship. 본 연구는 입체조형중심 미술치료가 시설거주 시각장애 아동의 또래 관계에 어떤 영향을 주는지 알아보는데 목적이 있다. 연구 대상은 Y거주시설에 거주하는 시각장애 아동 2명이며, 주 1∼2회, 50분 동안 미술치료를 총 24회기 진행하였다. 결과를 위한 자료처리는 매 회기별 미술치료 작품과 진행 내용을 관찰, 분석하였고, 추가 보완도구로는 사전, 중기, 사후 3차례에 걸쳐 생활재활교사와 학부모의 인터뷰와 Hudson(1987)이 개발한 또래관계 검사의 사전·사후 결과를 비교 분석하였다. 연구문제에 따른 결과를 요약하면, 첫째, 회기별 분석에서는 미술치료 초기와 중기 초반에는 상호간 부정적 표현이 많았으나, 후기부터는 협동조형 활동 속에서 상호배려 행동과 대화로 발전되었다. 둘째, 학부모와 생활재활교사 인터뷰에서도 생활에서의 긍정적인 행동과 모습이 관찰되었으며 셋째, 또래관계 검사결과 역시 사전보다 사후 상승됨으로 나타났다. 따라서 본 연구의 결과는 미술치료에서 입체조형의 창작 과정이 특히 시각장애 아동들에게 시각장애로 인해 보이지는 않지만 입체적인 작품을 만드는 동안 재료를 만지거나 타인의 작품을 감각적으로 체험하는 동안 자연스러운 상호교류를 만들어 내어 또래관계를 향상시키는데 어떠한 과정으로 확인되는지의 사례전형을 보여주었다는데 의미가 있다.

등온 정육면체 열원 주변 3차원 자연대류 온도장의 정량적 가시화

장욱,강민구,주원종,강보선,차동진 한밭대학교 생산기반기술연구소 2003 생산기반기술연구소 논문집 Vol.3 No.1

Holographic interferometric tomography has been used to reconstruct the three-dimensional temperature field around a single isothermal cube in an infinite medium. The technique, which mainly consists of interferometric fringe enhancement and analysis and computational tomography, becomes user-friendly by utilizing GUI(graphics user interface) environment. It can also reconstruct the reasonably complex, three-dimensional fluid flow in a relative short period of time. More systematic analysis of the three-dimensional field is underway, and the results will be reported shortly.

Lymphovenous anastomoses with three-dimensional digital hybrid visualization: improving ergonomics for supermicrosurgery in lymphedema

Will, Patrick A.,Hirche, Christoph,Berner, Juan Enrique,Kneser, Ulrich,Gazyakan, Emre Korean Society of Plastic and Reconstructive Surge 2021 Archives of Plastic Surgery Vol.48 No.4

The conventional approach of looking down a microscope to perform microsurgical procedures is associated with occupational injuries, anti-ergonomic postures, and increased tremor and fatigue, all of which predispose microsurgeons to early retirement. Recently, three-dimensional (3D) visualization of real-time microscope magnification has been developed as an alternative. Despite its commercial availability, no supermicrosurgical procedures have been reported using this technology to date. Lymphovenous anastomoses (LVAs) often require suturing vessels with diameters of 0.2-0.8 mm, thus representing the ultimate microsurgical challenge. After performing the first documented LVA procedure using 3D-augmented visualization in our unit and gaining experience with this technique, we conducted an anonymized in-house survey among microsurgeons who had used this approach. The participants considered that 3D visualization for supermicrosurgery was equivalent in terms of handling, optical detail, depth resolution, and safety to conventional binocular magnification. This survey revealed that team communication, resident education, and ergonomics were superior using 3D digital hybrid visualization. Postoperative muscle fatigue, tremor, and pain were also reduced. The major drawbacks of the 3D visualization microscopic systems are the associated costs, required space, and difficulty of visualizing the lymphatic contrast used.

Three-Dimensional Flow Visualization for the Steady and Pulsatile Flows in a Branching Model using the High-Resolution PIV System

Suh, Sang-Ho,Roh, Hyung-Woon Biomedical Engineering Society for Circulation 2004 International Journal of Vascular Biomedical Engin Vol.2 No.2

The objective of the present study is to visualize the steady and pulsatile flow fields in a branching model by using a high-resolution PIV system. A bifurcated flow system was built for the experiments in the steady and pulsatile flows. Harvard pulsatile pump was used to generate the pulsatile velocity waveforms. Conifer powder as the tracing particles was added to water to visualize the flow fields. CCD cameras($1K{\times}1K$(high resolution camera) and $640{\times}480$(low resolution camera)) captured two consecutive particle images at once for the image processing of several cross sections on the flow system. The range validation method and the area interpolation method were used to obtain the final velocity vectors with high accuracy. The results of the image processing clearly showed the recirculation zones and the formation of the paired secondary flows from the distal to the apex of the branch flow in the bifurcated model. The results also indicated that the particle velocities at the inner wall moved faster than the velocities at the outer wall due to the inertial force effects and the helical motions generated in the branch flows as the flow proceeded toward the outer wall. Even though the PIV images from the high resolution camera were closer to the simulation results than the images from the low resolution camera at some locations, both results of the PIV experiments from the two cameras generally agreed quite well with the results from the computer simulations. Therefore, instead of using the expensive stereoscopic PIV or 3D PIV system, the three-dimensional flow fields in a bifurcated model could be easily and exactly investigated by this study.

열교환기 브레이징 접합의 결함 형상 3차원 가시화

서상우,김진영 제어로봇시스템학회 2011 제어로봇시스템학회 국내학술대회 논문집 Vol.2011 No.5

삼차원 시각 자극을 이용한 f-MRI 연구

안창범,김치영,박호종,오승준 대한자기공명의과학회 2005 Investigative Magnetic Resonance Imaging Vol.9 No.1

목적 : 기존의 시각 자극과 관련한 뇌기능 연구가 일반적인 이차원 시각 자극을 이용한 데 반하여 본 논문에서는 삼차원 스트레오스코픽 비젼에 의한 시각 자극을 이용한 뇌기능 영상 연구를 수행하였다. 본 연구를 통하여 삼차원 시각처리와 관련한 뇌의 기능 영역 및 특징을 이차원 시각 자극 결과와 비교 검토하였다. 대상 및 방법 : Anaglyph(이차원 그림을 칼라 코딩한 후 왼쪽과 오른쪽에 서로 다른 색깔의 렌즈를 사용하여 스트레오스코픽 비젼을 구현)를 이용하여 삼차원 시각 자극을 주었으며, 이와 비교를 위하여 동일한 영상으로 이차원 시각 자극을 구현하였다. 건강한 volunteer들에 대하여 삼차원 및 이차원 시각 자극에 대한 뇌기능 영상을 3.0 Tesla MRI 시스템에서 얻었다. 결과 : 삼차원 시각 자극에 의하여 활성화된 뇌의 영역은 이차원 시각 자극과 동일하게 후두엽으로 나타났으며, 삼차원 시각 자극에 의한 활성영역이 이차원 시각 자극에 의한 영역 보다 약 18% 더 넓게 나타났다. 결론 : 사람은 양 눈을 사용하여 삼차원 물체를 인식한다. 삼차원 물체 인식은 스테레오스코픽 비젼에 기인하는데, anaglyph 를 이용하여 삼차원 시각 자극에 대한 뇌기능 영상을 3.0 Tesla MRI 시스템에서 수행하였다. 삼차원 시각 자극에 의하여 활성화된 뇌의 영역은 이차원 시각자극과 동일하게 후두엽으로 나타났으나, 활성영역이 이차원 자극에 비하여 약 18% 더 넓게 나타났다. 이것은 삼차원 영상 처리가 이차원 영상 처리에 비하여 왼쪽 영상과 오른쪽 영상의 차이에서 거리 정보를 추출하는 삼차원 시각 처리 기능이 추가됨에 따라 뇌의 처리 영역이 넓 어진 것으로 판단된다. 이러한 삼차원 시각 자극 뇌기능 영상은 가상현실이나 3-D 디스플레이, 3-D 멀티미디어 콘텐츠 연구 등 다양한 분야에 활용될 수 있을 것으로 기대한다.