• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.545-556
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• 2002

Bubble behaviors in two-phase flows have been analyzed by tomography methods such as an algebraic reconstruction technique (ART) and a multiplicative algebraic reconstruction technique (MART). Initially, a bubbly flow and an annular flow have been investigated by cross-sectional view using computer synthesized phantoms. Two tomography methods have been compared to obtain more accurate results of the two-phase flows. Then, reconstruction of three-dimensional density distributions of phantoms with two and three bubbles have been accomplished by the MART method which provided the better results for the two-dimensional reconstructions accurately to analyze the bubble behaviors in the two-phase flow.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.719-722
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• 2000

단일 카메라로 회전하는 물체의 영상을 획득한 후, 그 영상을 분석하여 3차원으로 복구하는 새로운 알고리즘을 제안한다. 제안하는 알고리즘은 물체의 회전과 단 하나의 카메라를 이용하는 방법이기에 기존의 스테레오 영상을 이용하는 방법에 비해 차이를 둘 수 있다. 회전하는 물체에는 회전축과 동일한 방향의 스캔라인을 형성시키고, 이 스캔라인을 적절한 측면에서 하나의 카메라를 이용해 영상으로 획득하여 스캔라인의 굴곡과 이 스캔라인에 인접한 화소의 컬러 정보를 이용하여 3차원의 물체를 재건한다. 이 방법은 3차원의 정보를 얻음에 있어 물체의 회전에 의존하기에 한 방향에서 얻어진 두 스테레오 영상의 정합과 각 방향에서 얻어진 영상을 정합 시킬 때 발생될 수 있는 스테레오 비전의 오류를 피할 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.571-573
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• 1999

수공으로 이루어지는 치아 재건을 3차원 모델링을 통하여 좀 더 정확하고 빠르게 제작하는데 있어 Conus 내관을 정확히 모델링하는 것은 매우 중요하다. Conus 내관을 모델링하기 위해 치과 의사가 만든 구강의 석고 모형으로부터 얻은 3차원 정보에서 실제 치아와 갈아낸 부분과의 경계인 변연(margin)을 정확히 찾아야 한다. 본 논문에서는 변연을 찾기 위한 방법으로 면의 노말 벡터(normal vector)와 치아의 기준 벡터와의 각도의 변화량을 이용하는 방법을 제시한다. 또한 변연으로부터 컴퓨터로 Conus 내관을 제작하는 방법을 소개한다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.598-600
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• 1999

본 논문은 수공으로 이루어지는 치과 치료 및 보철물 제작을 3차원 컴퓨터 모델링을 하여 좀 더 정확하고 빠른 시간에 처리할 수 있는 시스템을 소개한다. 이 시스템은 기존 2차원 기반이 아닌 3차원 기반으로 설계되었으며, 구강의 석고 모형을 3차원으로 컴퓨터에 모델링한 후, 모델링 정보로부터 능선(ridge), 교두(crusp), 피트(pit), 열구(fissure), 변연(margin) 등과 같은 치아 특성 정보추출과 교합면 생성을 통하여 보철물, 예를 들어 Conus 내관과 외관을 제작한다. 해부학적으로 무수히 많은 변수를 갖고 있는 구강 구조에 대해 본 논문에서는 이들 일련의 과정에서 요구되는 컴퓨터 모델링의 주요 기술들을 제시한다.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.193-197
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• 2010

Objectives : Patients with neck tumor and their family need every information about the disease. Especially, the size and location are confusing with verbal information. With the aid of CT, the problem had some answer, but it needs some medical education. We would like to know the usefullness of 3D reconstructed images in patient education about the disease. Material and Methods : Neck CT data were collected from 10 patients with various neck tumors and converted to 3D reconstructed images. Understanding of the patients about the size and location of tumors were rated from questionaires using axial CT images and 3D images. Results : Understanding score about 3D images were greater than that of CT images(p<0.006). Conclusion : 3D reconstructed images of CT could give the patients more real visual information about the disease.

• 대한두경부종양학회:학술대회논문집
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• 1995.11a
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• pp.207-208
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• 1995

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.339-347
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• 1996

Prior to the advent of microvascular surgery, conventional prosthetic rehabilitation offered limited success to re-establish the physiological function in oromaxillofacial reconstruction. Microvascular surgery provided a new frontier and there are multitude of flaps. Each flap has the benefits and limitation for the application to various defects. Advantage of the scapular flaps over other reconstructive methods include the ability to design multiple cutaneous panels on a separate vascular pedicle allowing improvement in three-dimensional relationship and osseointegrated implants can be palced to restore occlusal and masticatory function. Here I present the detailed description of the important surgical anatomy as well as graft dissection and clinical application of free vascularized scapular flap.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.517-523
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• 2011

Anterior cruciate ligament (ACL) injuries are treatedwith surgical reconstruction. Although ACL consists of two functional bundles, only the anteromedial bundle is surgically reconstructed, and the effect of the reconstruction of the posterolateral bundle is unknown. The purpose of this study is to investigate the role of the posterolateral bundle and the effect of double-bundle reconstruction during single-leg landing. A 3D dynamic knee with various ACL reconstructed models was created using MRI, and single-leg landing motion was simulated using in-vivo human experimental data. The results showed that the lateral shift of the tibial insertion of the anteromedial bundle and the posterolateral bundle of the ACL constrain the tibial internal rotation more efficiently than a single anteromedial bundle can. In addition, double-bundle ACL reconstruction is less sensitive to inaccuracies in the tibial tunnel placement.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.108-114
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• 2006

Transient and asymmetric density distributions of butane flow have been investigated from laser image signals by developed three-dimensional digital speckle tomography. Moved signals of speckles have been captured by multiple CCD images in three angles of view simultaneously because the flows were asymmetric and transient. The signals of speckle movements between no flow and downward butane flow from a circular half opening have been calculated by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays fur density gradients. The three-dimensional density fields have been reconstructed from the fringe shift signal which is integrated from the deflection angle by a real-time multiplicative algebraic reconstruction technique (MART).

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.198-203
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• 2010

Objectives : Getting full information from axial CT images needs experiences and knowledge. Sagittal and coronal images could give more information but we have to draw 3-dimensional images in mind with above informations. With aid of 3D reconstruction softwares, CT data are converted to visible 3D images. We tried to compare medical photographs of 15 surgical specimens from neck tumors with 3D reconstructed images of same patients. Material and Methods : Fifteen patients with neck tumors treated surgically were recruited. Medical photograph of the surgical specimens were collected for comparison. 3D reconstruction of neck CT from same patients with aid of 3D-doctor software gave 3D images of neck masses. Width and height of tumors of each photos and images from the same cases were calculated and compared statistically. Visual similarities were rated between photos and 3D images. Results : No statatistical difference were found in size between medical photos and 3D images. Visual similarity score were higher between 2 groups of images. Conclusion : 3D reconstructed images of neck mass looked alike the real photographs of excised neck mass with similar calculated sizes. It could give us reliable visual information about the mass.