• 한국멀티미디어학회논문지
• /
• 제22권12호
• /
• pp.1385-1395
• /
• 2019

In this paper, we propose a method to fabricate a patient-specific breast implant using MRI images and 3D scan data. Existing breast implants for breast reconstruction surgery are primarily fabricated products for shaping, and among the limited types of implants, products similar to the patient's breast have been used. In fact, the larger the difference between the shape of the breast and the implant, the more frequent the postoperative side effects and the lower the satisfaction. Previous researches on the fabrication of patient-specific breast implants have used limited information based on only MRI images or on only 3D scan data. In this paper, we propose an algorithm for the fabrication of patient-specific breast implants that combines MRI images with 3D scan data, considering anatomical suitability for external shape, volume, and pectoral muscle. Experimental results show that we can produce precise breast implants using the proposed algorithm.

• 대한치과의사협회지
• /
• 제12권9호
• /
• pp.691-694
• /
• 1974

The trends of restoration on abrased teethis mostly based on gnathology or on practical experience. This study was performed on plaster models from 60 young men whose teeth and occlusion are clinically normal. A pair, upper and lower models, were mounted on HANAU articulator. Iron ball bearing 0.2mm 0.5mm 0.7mm and 1.0mm in diameter was attached on mesiobuccal cusp of upper first molar. [table I] Long ribbon shape of cold cure resin was inserted and jaw was closed gently so as not to move disturb original position of iron ball. The resin bite registration was measured minimun thickness from each lingual cusps of upper jaw and buccal cusps of lower jaw by means of Bowley gauge. The results were as follows (graph). 1) The distance from upper lingual cusps and lower buccal cusps: backward cusps showed smaller than standard cusp (upper mesio-buccal cusp) and forward cusps showed longer than standard. 2) The measurements from upper lingual cusps are not coincide with lower buccal cusps.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 2009년도 IWAIT
• /
• pp.566-571
• /
• 2009

A calibration method for multiple sets of stereo vision cameras is proposed. To measure the three-dimensional shape of a very long object, measuring the object at different viewpoints and registration of the data are necessary. In this study, two lasers beams generate two strings of calibration targets, which form straight lines in the world coordinate system. An evaluation function is defined to calculate the sum of the squares of the distances between each transformed target and the fitted line representing the laser beam to each target, and the distances between points appearing in the data sets of two adjacent viewpoints. The calculation process for the approximation method based on data linearity is presented. The experimental results show the effectiveness of the method.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
• /
• pp.848-853
• /
• 2005

3D geometric modeling of an object of interest has been intensively investigated in many fields including CAD/CAM and computer graphics. Traditionally, CAD and geometric modeling tools are widely used to create geometric models that have nearly the same shape of 3D real objects or satisfy designers intent. Recently, with the help of the reverse engineering (RE) technology, we can easily acquire 3D point data from the objects and create 3D geometric models that perfectly fit the scanned data more easily and fast. In this paper, we present 3D geometric model generation based on a stereo vision system (SVS) using random pattern projection. A triangular mesh is considered as the resulting geometric model. In order to obtain reasonable results with the SVS-based geometric model generation, we deal with many steps including camera calibration, stereo matching, scanning from multiple views, noise handling, registration, and triangular mesh generation. To acquire reliable stere matching, we project random patterns onto the object. With experiments using various random patterns, we propose several tips helpful for the quality of the results. Some examples are given to show their usefulness.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
• /
• pp.238-242
• /
• 2007

Today's commercial high resolution satellite imagery such as that provided by IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Digital maps supply the most generally used GIS data probiding topography, road, and building information. Currently, the building information provided by digital maps is incompletely constructed for GIS applications due to planar position error and warped shape. We focus on extracting of the accurate building information including position, shape, and height to update the building information of the digital maps and GIS database. In this paper, we propose a new method of 3D building information extraction with a single high resolution satellite image and digital map. Co-registration between the QuickBird image and the 1:1,000 digital maps was carried out automatically using the RPC adjustment model and the building layer of the digital map was projected onto the image. The building roof boundaries were detected using the building layer from the digital map based on the satellite azimuth. The building shape could be modified using a snake algorithm. Then we measured the building height and traced the building bottom automatically using triangular vector structure (TVS) hypothesis. In order to evaluate the proposed method, we estimated accuracy of the extracted building information using LiDAR DSM.

• 정보과학회 논문지
• /
• 제42권10호
• /
• pp.1222-1230
• /
• 2015

무릎 자기공명영상에서 전방십자인대의 분할은 밝기값의 불균일성 및 주변 조직들과의 유사 밝기값 특성으로 인해 기존 분할기법의 적용에 한계가 있다. 본 논문에서는 지역적 정렬을 통한 확률아틀라스 생성 및 반복적 그래프 컷을 통한 다중아틀라스 기반 전방십자인대 분할기법을 제안한다. 첫째, 전역 및 지역적 다중아틀라스 강체정합을 통해 전방십자인대의 확률아틀라스를 생성한다. 둘째, 생성된 확률아틀라스를 이용하여 최대사후추정 및 그래프 컷을 통하여 전방십자인대 초기 분할을 수행한다. 셋째, 마스크 기반 강체정합을 통한 형상정보 개선 및 반복적 그래프 컷을 통해 전방십자인대 분할 개선을 수행한다. 제안방법의 성능평가를 위하여 육안평가 및 정확성평가를 수행하였으며, 평가 결과 제안방법의 Dice 유사도는 75.0%, 평균표면거리는 1.7화소, 제곱근표면거리는 2.7화소로서 기존 그래프 컷 방법에 비하여 전방 십자인대의 분할정확도가 각각 12.8%, 22.7%, 및 22.9% 향상된 것으로 나타났다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
• /
• pp.25-28
• /
• 2006

We propose a new method of masking cloud-affected pixels in satellite ocean color imageries such as of GLI. Those pixels, mostly found around cloud pixels or in scattered cloud area, have anomalous features in either in chlorophyll-a estimate or in water reflectance. This artifact is most likely caused by residual error of inter-band registration correction. Our method is to check the pixel-wise 'soundness' of the spectral water reflectance Rw retrieved after the atmospheric correction. First, we define two spectral ratio between water reflectance, IRR1 and IRR2, each defined as RW(B1)/RW (B3) RW (B3) and as RW (B2)/RW(B4) respectively, where $B1{\sim}B4$ stand for 4 consecutive visible bands. We show that an almost linear relation holds over log-scaled IRR1 and IRR2 for shipmeasured RW data of SeaBAM in situ data set and for GLI cloud-free Level 2 sub-scenes. The method we propose is to utilize this nature, identifying those pixels that show significant discrepancy from that relationship. We apply this method to ADEOS-II/GLI ocean color data to evaluate the performance over Level-2 data, which includes different water types such as case 1, turbid case 2 and coccolithophore bloom waters.

• 대한원격탐사학회지
• /
• 제35권1호
• /
• pp.15-28
• /
• 2019

By applying the method of SAR interferometry to X-band synthetic aperture radar (SAR) image of COSMO-SkyMed, detailed motion patterns of five glaciers in the Parlung Zangbo River basin, Tibetan Plateau, in January 2010 have been derived. The results indicate that flow patterns are generally constrained by the valley geometry and terrain complexity. The maximum of $123.9ma^{-1}$ is observed on glacier No.1 and the minimum of $39.4ma^{-1}$ is found on glacier No.3. The mean values of five glaciers are between 22.9 and $98.2ma^{-1}$. Glaciers No.1, No.2, No.4 and No.5 exhibit high velocities in their upper sections with big slope and low velocities in the lower sections. A moraine lake accelerates the speed of mass exchange leading to a fast flow at the terminal of glacier No.3. These glaciers generally move along the direction of decreased elevation and present a macroscopic illustration of the motion from the northwest to the southeast. The accuracy of DEM and registration conditions of DEM-simulated terrain phases has certain effects on calculations of glacier flow direction and velocity. The error field is relatively fragmented in areas inconsistent with the main flow line of the glaciers, and the shape and uniformity of glacier are directly related to the continuous distribution of flow velocity errors.

• 한국의학물리학회지:의학물리
• /
• 제30권1호
• /
• pp.32-38
• /
• 2019

Purpose: The objective of this study is to evaluate the geometrical accuracy of a patient-specific bolus based on a three-dimensional (3D) printed mold and casting method. Materials and Methods: Three breast cancer patients undergoing treatment for a superficial region were scanned using computed tomography (CT) and a designed bolus structure through a treatment planning system (TPS). For the fabrication of patient-specific bolus, we cast harmless certified silicone into 3D printed molds. The produced bolus was also imaged using CT under the same conditions as the patient CT to acquire its geometrical shape. We compared the shapes of the produced bolus with the planned bolus structure from the TPS by measuring the average distance between two structures after a surface registration. Results and Conclusions: The result of the average difference in distance was within 1 mm and, as the worst case, the absolute difference did not exceed ${\pm}2mm$. The result of the geometric difference in the cross-section profile of each bolus was approximately 1 mm, which is a similar property of the average difference in distance. This discrepancy was negligible in affecting the dose reduction. The proposed fabrication of patient-specific bolus is useful for radiation therapy in the treatment of superficial regions, particularly those with an irregular shape.

• 박물관보존과학
• /
• 제22권
• /
• pp.15-26
• /
• 2019

이 연구에서는 표면형상 취득에 최적화되어 있는 광학식 정밀스캐닝과 내부 형상획득에 사용되는 X-선 CT스캐닝 결과를 이용하여 삼총통의 내·외부 형상을 다각적으로 분석할 수 있는 3차원(이하 3D) 융합 모델을 제작하였다. 먼저 두 스캐닝 결과를 호환 가능한 확장자로 변환 한 다음 상호간의 정합성을 검증하고자 3D 편차분석을 수행하였다. 이 결과, 두 스캐닝 모델은 대부분(56.98%) ±0.1mm 이내의 편차를 보였으며, 이 수치는 ICP 알고리즘 기반의 정합 및 병합에 큰 영향을 주지 않았다. 병합된 데이터는 총통의 외부 표면색 및 미세형상, 내부 두께 및 구조를 잘 표현하였다. 광학식 표면스캐닝과 X-선 CT스캐닝의 3D 융합 모델은 문화유산의 디지털기록화뿐만 아니라 제작기법 해석에 유용하게 사용되었다. 향후 박물관 전시 영역에서 전시품의 과학적 조사 정보를 보다 쉽게 관람객에게 전달하는 효과를 발휘 할 것으로 기대된다.