• Title/Summary/Keyword: 삼차원영상 시스템

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Structural and Functional Changes of Hippocampus in Long Life Experienced Taxi Driver (오랜 운전경험을 가진 택시운전기사들의 해마의 구조와 기능적 변화에 대한 MRI연구)

  • You, Myung-Won;Lee, Dong-Kyun;Lee, Jong-Min;Kim, Sun-Mi;Ryu, Chang-Woo;Kim, Eui-Jong;Jahng, Geon-Ho
    • Investigative Magnetic Resonance Imaging
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    • v.16 no.2
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    • pp.124-135
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    • 2012
  • Purpose : The objective of this study was to investigate the differences of hippocampal volume and shape as well as the functional change between long life experienced taxi drivers and controls of Korean population. Materials and Methods: Three-dimensional T1-weighted images and blood oxygen level dependent functional MRI(fMRI) were obtained from 8 subjects, consisting of 4 experienced (20-30 years) taxi drivers and 4 age-matched controls. The hippocampal volume and shape were analyzed with three-dimensional T1-weighted images. In addition, neuronal activities of brain were analyzed using a blood oxygen level dependent fMRI between the two groups. Results: The hippocampal volume showed no statistically significant difference between the two groups (p > 0.05). The left hippocampi of the taxi drivers were slightly elongated with larger head and tail portions than those of the controls (p < 0.05, uncorrected). For the functional MRI, fusiform gyrus was specifically activated in taxi drivers, compared with the control group. Conclusion: The structural and functional changes of taxi driver's hippocampus indicate the functional differentiation as a result of occupational dependence on spatial navigation. In other words, the continuous usage of spatial navigation performance may diminish degeneration of hippocampus and the related brain regions.

Color correction of tile color input device using the Neural Network (신경망을 이용한 칼라 입력장치의 칼라 보정)

  • Eum, Kyoung-Bae;Ahn, Chang-Sun
    • Journal of The Korean Association of Information Education
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    • v.3 no.1
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    • pp.134-142
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    • 1999
  • The demand for recognizing the color as well as the object shape is increasing to use the detailed information, because-the expense of color input/output devices become cheap. The research on the color correction should be researched for the exact color presentation and color reproduction of color input/output systems. In this paper, we researched on the color correction of color scanner. The characterization of color scanner is a two step process of gray-balancing and color transformation. The decoupling of the gray-balancing from the color transformation enables the portability of the scanner characterization. We used the least square methods for the line fitting and the Neural Network for the storage space and computation speed. The output of Neural Network is similar to the target value in three-dimensional tristimulus space. The proposed color correction method can be used for all scanners of a manufacturer's model because of the portability.

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Three Dimensional Volume Reconstruction of an Object from X-ray Iamges using Uniform and Simultaneous ART (USART 방법에 의한 X선 영상으로부터의 삼차원 물체의 형상 복원)

  • Roh, Young-Jun;Cho, Hyung-Suck;Kim, Hyeong-Cheol;Kim, Jong-Hyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.1
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    • pp.21-27
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    • 2002
  • Inspection and shape measurement of three-dimensional objects are widely needed in industries for quality monitoring and control. A number of visual or optical technologies have been successfully applied to measure three-dimensional surfaces. However, those conventional visual or optical methods have inherent shortcomings such as occlusion and variant surface reflection. X-ray vision system can be a good solution to these conventional problems, since we can extract the volume information including both the surface geometry and the inner structure of any objects. In the x-ray system, the surface condition of an object, whether it is lambertian or specular, does not affect the inherent characteristics of its x-ray images. In this paper, we propose a three-dimensional x-ray imaging method to reconstruct a three dimensional structure of an object out of two dimensional x-ray image sets. To achieve this by the proposed method, two or more x-ray images projected from different views are needed. Once these images are acquired, the simultaneous algebraic reconstruction technique(SART) is usually utilized. Since the existing SART algorithms have several shortcomings such as low performance in convergence and different convergence within the reconstruction volume of interest, an advanced SART algorithm named as USART(uniform SART) is proposed to avoid such shortcomings and improve the reconstruction performance. Because, each voxel within the volume is equally weighted to update instantaneous value of its internal density, it can achieve uniform convergence property of the reconstructed volume. The algorithm is simulated on various shapes of objects such as a pyramid, a hemisphere and a BGA model. Based on simulation results the performance of the proposed method is compared with that of the conventional SART method.

The Effect of Accommodation Cue Manipulation at Stereoscopic Display on Binocular Fusion (양안식 디스플레이에 제시되는 자극의 조절단서 조작이 양안융합에 미치는 영향)

  • Park, Jong-Jin;Kim, Shinwoo;Li, Hyung-Chul O.
    • Journal of Broadcast Engineering
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    • v.27 no.4
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    • pp.569-580
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    • 2022
  • In this study, we investigated the effect of peripheral blur on binocular fusion to resolve binocular fusion failure which is one of the 3D visual fatigues in the perspective of human visual system. With stimulus having discrete disparity change, binocular fusion failure rate for target stimulus having crossed and uncrossed disparity decreased. And target stimulus having continuous disparity also required relatively larger binocular disparity when peripheral blur was presented with target stimulus rather than when peripheral blur was not presented. These results imply that peripheral blur facilitated binocular fusion in the situation of binocular disparity change, and suggest that considering the characteristics of human three-dimensional visual systems, manipulating 3D contents can improve visual discomfort caused by binocular displays at low costs.

Preliminary Results of 3-Dimensional Conformal Radiotherapy for Primary Unresectable Hepatocellular Carcinoma (절제 불가능한 원발성 간암의 입체조형 방사선치료의 초기 임상 결과)

  • Keum Ki Chang;Park Hee Chul;Seong Jinsil;Chang Sei Kyoung;Han Kwang Hyub;Chon Chae Yoon;Moon Young Myoung;Kim Gwi Eon;Suh Chang Ok
    • Radiation Oncology Journal
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    • v.20 no.2
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    • pp.123-129
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    • 2002
  • Purpose : The purpose of this study 띤as to determine the potential role of three-dimensional conformal radiotherapy (3D-CRT) in the treatment of primary unresectable hepatocellular carcinoma. The preliminary results on the efficacy and the toxicity of 3D-CRT are reported. Materials and Methods : Seventeen patients were enrolled in this study, which was conducted prospectively from January 1995 to June 1997. The exclusion criteria included the presence of extrahepatic metastasis, liver cirrhosis of Child-Pugh classification C, tumors occupying more than two thirds of the entire liver, and a performance status of more than 3 on the ECOG scale. Two patients were treated with radiotherapy only while the remaining 15 were treated with combined transcatheter arterial chemoembolization. Radiotherapy was given to the field including the tumor plus a 1.5 cm margin using a 3D-CRT technique. The radiation dose ranged from $36\~60\;Gy$ (median; 59.4 Gy). Tumor response was based on a radiological examination such as the CT scan, MR imaging, and hepatic artery angiography at $4\~8$ weeks following the completion of treatment. The acute and subacute toxicities were monitored. Results : An objective response was observed in 11 out of 17 patients, giving a response rate of $64.7\%$. The actuarial survival rate at 2 years was $21.2\%$ from the start of radiotherapy (median survival; 19 months). Six patients developed a distant metastasis consisting of a lung metastasis in 5 patients and bone metastasis in one. The complications related to 30-CRT were gastro-duodenitis $(\geq\;grade\;2)$ in 2 patients. There were no treatment related deaths and radiation induced hepatitis. Conclusion : The preliminary results show that 3D-CRT is a reliable and effective treatment modality for primary unresectable hepatocellular carcinoma compared to other conventional modalities. Further studies to evaluate the definitive role of the 3D-CRT technique in the treatment of primary unresectable hepatocellular carcinoma are needed.

First Experience of Cardiac Surgery using da $Vinci^{TM}$ Surgical System in Korea (da $Vinci^{TM}$ 수술로봇을 이용한 심장수술 - 첫 번째 치험 보고)

  • Park, Seong-Yong;Lee, Sak;Joo, Hyun-Chul;Yang, Hong-Suk;Park, Young-Hwan;Park, Har-Ki
    • Journal of Chest Surgery
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    • v.40 no.2 s.271
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    • pp.128-131
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    • 2007
  • da $Vinci^{TM}$ Surgical System is an advanced mode of minimal invasive surgery, using 3-dimensional imaging system and robotic arms which can mimic the dexterity of the human hand. Thus, various operations can be performed with minimal incision and limited surgical field and the merits of minimal invasive surgery can be maximized by using it. We report our first experience of robotic open heart surgery using the da $Vinci^{TM}$ Surgical System for repairing atrial septal defect.

Convergence and integration study related to development of digital contents for radiography training using dental radiograph and augmented reality (치과방사선사진과 증강현실을 활용한 방사선촬영법 숙련용 디지털 콘텐츠 개발에 대한 융복합 연구)

  • Gu, Ja-Young;Lee, Jae-Gi
    • Journal of Digital Convergence
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    • v.16 no.12
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    • pp.441-447
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    • 2018
  • This study aims to develop digital techniques that enable repeated practice of dental radiography using augmented reality technology. A three-dimensional object was fabricated by superimposing a photograph of an adult model and a computed tomography image of a manikin phantom. The system was structured using 106 radiographs such that one of these saved radiographs is opened when the user attempts to take a radiograph on a mobile device. This system enabled users to repeatedly practice at the pre-clinical stage without exposure to radiation. We attempt to contribute to enhancing dental hygienists' competency in dental radiography using these techniques. However, a system that enables the user to actually take a radiograph based on face recognition would be more useful in terms of practice, so additional studies are needed on the topic.

Development of Operational Technology and Integrated Measurement Information Management System for the Radioactivity Measurement Device (방사능 측정장치 운영 기술 및 측정정보 통합관리 시스템 개발)

  • Dong-Sik Jin;Kyeong-Ryeong Kim;Jae-Geun Lee
    • Journal of radiological science and technology
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    • v.47 no.3
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    • pp.183-195
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    • 2024
  • Additional functional upgrades to the large-area compton camera (LACC) measurement device that can provide characteristics evaluation information (nuclear species and radioactivity) and two-dimensional or three-dimensional distribution imaging information of radioactive materials existing in surface or internal of concrete structures are required in terms of work stability and efficiency in order to apply to actual decommissioning sites such as nuclear power plants or medical cyclotron facilities by using this measurement device. To this purpose, the technology that allows radiation workers to intuitively and visually check the distribution of radioactive materials in advance by matching the two-dimensional distribution imaging information of radioactive materials obtained through the LACC measurement device and visual imaging of the measurement zone (10 m × 5 m) was developed. In addition, the separate system that can automatically adjust the position (height) in units of the measurement area size (0.7 m × 0.3 m × 0.8 m) of the LACC measurement device was developed and the integrated management system for characteristics evaluation information and two-dimensional or three-dimensional distribution imaging information obtained per unit of measurement for radioactive materials was developed. These functional upgrades related to LACC measurement device can improve work efficiency and safety when measuring radioactivity of concrete structures and enable the establishment of appropriate decommissioning strategies using radioactivity measurement information for decommissioning nuclear power plants or medical cyclotron facilities.

A Fast Flight-path Generation Algorithm for Virtual Colonoscopy System (가상 대장 내시경 시스템을 위한 고속 경로 생성 알고리즘)

  • 강동구;이재연;나종범
    • Journal of Biomedical Engineering Research
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    • v.24 no.2
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    • pp.77-82
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    • 2003
  • Virtual colonoscopy is a non-invasive computerized procedure to detect polyps by examining the colon from a CT data set. To fly through the inside of colons. the extraction of a suitable flight-path is necessary to Provide the viewpoint and view direction of a virtual camera. However. manual path extraction by Picking Points is a very time-consuming and difficult task due 1,c, the long and complex shape of colon. Also, existing automatic methods are computationally complex. and tend to generate an improper and/or discontinuous path for complicated regions. In this paper, we propose a fast flight-path generation algorithm using the distance and order maps. The order map Provides all Possible directions of a path. The distance map assigns the Euclidean distance value from each inside voxel to the nearest background voxel. By jointly using these two maps. we can obtain a proper centerline regardless of thickness and curvature of an object. Also, we Propose a simple smoothing technique that guarantees not to collide with the surface of an object. The phantom and real colon data are used for experiments. Experimental results show that for a set of human colon data, the proposed algorithm can provide a smoothened and connected flight-path within a minute on an 800MHz PC. And it is proved that the obtained flight-Path provides successive volume-rendered images satisfactory for virtual navigation.

Documentation of Intangible Cultural Heritage Using Motion Capture Technology Focusing on the documentation of Seungmu, Salpuri and Taepyeongmu (부록 3. 모션캡쳐를 이용한 무형문화재의 기록작성 - 국가지정 중요무형문화재 승무·살풀이·태평무를 중심으로 -)

  • Park, Weonmo;Go, Jungil;Kim, Yongsuk
    • Korean Journal of Heritage: History & Science
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    • v.39
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    • pp.351-378
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    • 2006
  • With the development of media, the methods for the documentation of intangible cultural heritage have been also developed and diversified. As well as the previous analogue ways of documentation, the have been recently applying new multi-media technologies focusing on digital pictures, sound sources, movies, etc. Among the new technologies, the documentation of intangible cultural heritage using the method of 'Motion Capture' has proved itself prominent especially in the fields that require three-dimensional documentation such as dances and performances. Motion Capture refers to the documentation technology which records the signals of the time varing positions derived from the sensors equipped on the surface of an object. It converts the signals from the sensors into digital data which can be plotted as points on the virtual coordinates of the computer and records the movement of the points during a certain period of time, as the object moves. It produces scientific data for the preservation of intangible cultural heritage, by displaying digital data which represents the virtual motion of a holder of an intangible cultural heritage. National Research Institute of Cultural Properties (NRICP) has been working on for the development of new documentation method for the Important Intangible Cultural Heritage designated by Korean government. This is to be done using 'motion capture' equipments which are also widely used for the computer graphics in movie or game industries. This project is designed to apply the motion capture technology for 3 years- from 2005 to 2007 - for 11 performances from 7 traditional dances of which body gestures have considerable values among the Important Intangible Cultural Heritage performances. This is to be supported by lottery funds. In 2005, the first year of the project, accumulated were data of single dances, such as Seungmu (monk's dance), Salpuri(a solo dance for spiritual cleansing dance), Taepyeongmu (dance of peace), which are relatively easy in terms of performing skills. In 2006, group dances, such as Jinju Geommu (Jinju sword dance), Seungjeonmu (dance for victory), Cheoyongmu (dance of Lord Cheoyong), etc., will be documented. In the last year of the project, 2007, education programme for comparative studies, analysis and transmission of intangible cultural heritage and three-dimensional contents for public service will be devised, based on the accumulated data, as well as the documentation of Hakyeonhwadae Habseolmu (crane dance combined with the lotus blossom dance). By describing the processes and results of motion capture documentation of Salpuri dance (Lee Mae-bang), Taepyeongmu (Kang seon-young) and Seungmu (Lee Mae-bang, Lee Ae-ju and Jung Jae-man) conducted in 2005, this report introduces a new approach for the documentation of intangible cultural heritage. During the first year of the project, two questions have been raised. First, how can we capture motions of a holder (dancer) without cutoffs during quite a long performance? After many times of tests, the motion capture system proved itself stable with continuous results. Second, how can we reproduce the accurate motion without the re-targeting process? The project re-created the most accurate motion of the dancer's gestures, applying the new technology to drew out the shape of the dancers's body digital data before the motion capture process for the first time in Korea. The accurate three-dimensional body models for four holders obtained by the body scanning enhanced the accuracy of the motion capture of the dance.