• Title/Summary/Keyword: Surface reconstruction

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The usability analysis of the Ray-sum technique and SSD (Shaded Surface display) technique in stomach CT Scan (위장 CT 검사에서 Ray-sum 기법과 SSD(Shaded Surface Display) 기법의 유용성 분석)

  • Kim, Hyun-Joo;Cho, Jae-Hwan;Song, Hoon
    • Journal of Digital Contents Society
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    • v.12 no.2
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    • pp.151-156
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    • 2011
  • The analysis and image evaluation the Ray-sum technique and Shaded Surface Display (under SSD) technique which is the reconstruction image processing technique after the CT scan was evaluated and the usability of the three-dimensional information offering was confirmed in the patient with stomach cancer. After obtaining the raw data by using 64-MDCT in 20 patient with stomach cancers, the image reconstruction processing was done. It was evaluated to describe accurately the analyzed result Ray-sum and SSD reconstruction image everyone anatomical structure. In the precision estimation of the image, the lesion location could coincide in the Ray-sum and SSD reconstruction image majority with the gastro fiberscope and we can know than the gastro fiberscope over 6cm that there was the error. In addition, We could know that degree of accordance of the results of the image interpretation about the lesion and endoscope and pathological opinion were high.

Reconstruction for the Soft Tissue Defect of Heel using Free Lateral Arm Neurosensory Flap (유리 외측 상박 감각신경 피판술을 이용한 종부 연부조직 결손의 재건)

  • Kim, Dong-Churl;Kim, Sang-Soo;Ha, Dae-Ho;Yoo, Hee-Jun;Lee, Dong-Hoon
    • Archives of Reconstructive Microsurgery
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    • v.8 no.1
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    • pp.15-21
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    • 1999
  • Soft tissue defect on heel area of the foot present difficult problems particularly because of anatomic property of plantar surface of the foot. There is a paucity of available local tissue in the foot for coverage. In addition to having little expandable tissue, the foot's plantar surface has a unique structure, making its replacement especially challenging. Plantar skin is attached to the underlying bone by fibrous septa, preventing shear of the soft-tissue surfaces from the underlying skeleton. Plantar surface of foot is in constant contact with the environment. Protective sensibility also would be maintained or restored in the ideal reconstruction. So the ideal flap for reconstruction of the heel should include thin, durable hairless skin with potential for reinnervation. The aim of this article is to present a clinical experience of free lateral arm neurosensory flap for reconstruction of the heel. From March 1995 to December 1997, a total 16 lateral arm free flaps were performed to soft tissue defects on the weight-bearing area of the hindfoot. we used tibial nerve as recepient nerve in 11 and calcaneal branch of tibial nerve in 5 for restoration of sensibility of flap. All cases survived completely. A static two-point discrimination of 14 to 34mm was detected in the flap. Radial nerve palsy which was caused by hematoma in donor site occured in one case, but recorverd in 3 weeks later completely. In conclusion, the lateral arm free flaps are versatile, reliable and sensible cutaneous flap and especially indicated for soft tissue defect on plantar surface of the hindfoot which are not good indications for other better-known flaps.

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3D Reconstruction of Tissue from a few of MRI Images using Radial Basis Function (BBF를 이용한 적은 수의 MRI 이미지로부터 3차원 조직 재구성)

  • Shin, Young-Seok;Kim, Hyoung-Seok B.
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.2077-2082
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    • 2008
  • Recent the advanced technologies in medical imaging such as magnetic resonance imaging (MRI) and computed tomography (CT) make doctors improve the diagnostic skill with detailed anatomical information. In general, it is necessary to get a number of MRI images in order to obtain more detail information. However, the performance of MRI machines of privately run hospitals is not good and thus we may obtain only a few of MRI images. If 3D surface reconstruction is accomplished with a few slices, then it generates 3D surface of poor qualify. This paper propose a way to Set a 3D surface of high quality from a few of number of slices. First of all, our algorithm detects the boundary of tissues which we want to reconstruct as a 3D object and find out the set of vortices on the boundary. And then we generate a 3D implicit surface to interpolate the boundary points by using radial basis function. Lastly, we render the 3D implicit surface by using Marching cube algorithms.

Study of Acoustic Holography using Equivalent Source Method with Continuation of Acoustic Near-field (근접음장 연속법과 등가 음원법을 이용한 음향홀로그래피 연구)

  • Kim, Sung-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.643-648
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    • 2011
  • This paper deals with the ESM(equivalent source method) with the continuation of acoustic near-field for NAH(near-field acoustic holography) to overcome the finite measurement aperture effect and reconstruct the normal velocity on an arbitrarily shaped structure surface. The continuation method is an extension of the measured sound field into a region outside and is based on the Green's function relating acoustic quantities on the two conformal surfaces. This algorithm is not limited to planar surfaces and can be applied to arbitrarily shaped surfaces. The ESM is an alternative approach of BEM-based NAH for the reconstruction on a general structure. In ESM the acoustic field is represented by a set of point sources located over a surface that is close to the structure surface. The simulation results of this study shows that the reconstruction error of particle velocity on the source surface is 11% and 16% for planar and cylindrical sources separately.

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Simulation of Diamond (100) and (110) Surface Structure and Surface Energy (Diamond(100) 및 (110) 표면구조와 표면에너지의 시뮬레이션)

  • 이종무
    • Journal of the Korean Vacuum Society
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    • v.3 no.3
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    • pp.269-274
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    • 1994
  • Tersoff 포텐셜을 사용한 에너지 최소화테크닉에 의하여 컴퓨터 시뮬레이션함으로써 다이아몬드 (100)과 (110) 표면의 구조와 표면에너지를 구하였다, 다이아몬드(100)면과 (110)면의 reconstruction pattern 은 각각 (1$\times$1)과 (2$\times$1)이며 표면에너지는 각각 6,671.3 erg/cm2 와 4,032.0 erg/cm2 인 것으로 계산되었다 (100)면의 surface reconstruction 은 첫 번째 원자층과 두 번째 원자층간의 간격이 [100] 방 향으로 수축되는 것으로 나타났다. 한편 (110)면의 surface reconstruc-tion은 주로 첫 번째 원자층에서 의 원자들은 [001] 방향으로 dimerization 한는 것과 첫 번째 원자층과 두 번째 원자층간의 간격이 [110] 방향으로 dimerization 하는 것과 첫 번째 원자층과 두 번째 원자층간의 간격이 [110] 방향으로 수축되 는 것으로 나타났다. 그밖에 표면의 각 원자층의 stress 성분들이 구해졌으며 그것들이 표면흡착에 미치 는 효과 등이 토의되었다.

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A Study on the Optimization for Three Dimensional Reconstruction of Bio Surface Using by Stereo Vision (스테레오 비젼에 의한 생체표면 3차원 복원의 최적화 연구)

  • Lee, Kyungchai;Lee, Onseok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.1
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    • pp.107-113
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    • 2017
  • Unlike regular images, there is no ground truth for bio surface images. Result of biosurface imaging is not only significantly affected by the environment and the condition of the bio surface, it requires more detailed expression than regular images. Therefore, unlike algorithms tested on regular images, studies on bio surface images requires a highly precise optimization process. We aim to optimize the graph cut algorithm, known to be the most outstanding among the stereo visions, by considering baseline, lambda, and disparity range. Optimal results were in the range of 1~10 for lambda. The disparity ranged from -30 to -50, indicating an optimal value in a slightly higher range. Furthermore, we verified the tested optimization data using SIFT.

NUMERICAL SIMULATION OF MULTIPHASE FLOW USING LEVEL CONTOUR RECONSTRUCTION METHOD (Level Contour Reconstruction 방법을 이용한 다상유동 수치해석)

  • Shin, Seung-Won
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.193-200
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    • 2009
  • Recently, there have been efforts to construct hybrids among the existing methodologies for multiphase flow such as VOF, Level Set, and Front Tracking with the intention of facilitating simulations of general three-dimensional problems. As one of the hybrid method, we have developed the Level Contour Reconstruction Method (LCRM) for general three-dimensional multiphase flows including phase change. The main idea was focused on simplicity and a robust algorithm especially for the three-dimensional case. It combines characteristics of both Front Tracking and Level Set methods. While retaining an explicitly tracked interface using interfacial elements, the calculation of a vector distance function plays a crucial role in the periodic reconstruction of the interface elements in the LCRM method to maintain excellent mass conservation and interface fidelity. In addition, compact curvature formulation is incorporated for the calculation of the surface tension force thereby reducing parasitic currents to a negligible level.

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Reconstruction of Buildings from Satellite Image and LIDAR Data

  • Guo, T.;Yasuoka, Y.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.519-521
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    • 2003
  • Within the paper an approach for the automatic extraction and reconstruction of buildings in urban built-up areas base on fusion of high-resolution satellite image and LIDAR data is presented. The presented data fusion scheme is essentially motivated by the fact that image and range data are quite complementary. Raised urban objects are first segmented from the terrain surface in the LIDAR data by making use of the spectral signature derived from satellite image, afterwards building potential regions are initially detected in a hierarchical scheme. A novel 3D building reconstruction model is also presented based on the assumption that most buildings can be approximately decomposed into polyhedral patches. With the constraints of presented building model, 3D edges are used to generate the hypothesis and follow the verification processes and a subsequent logical processing of the primitive geometric patches leads to 3D reconstruction of buildings with good details of shape. The approach is applied on the test sites and shows a good performance, an evaluation is described as well in the paper.

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Partial Knee Joint Defect Reconstruction with Vascularized Proximal Fibular Articular Surface (슬관절 부분결손에 대한 혈관부착 비골근위 관절면을 이용한 재건술)

  • Chung, Duke-Whan
    • Archives of Reconstructive Microsurgery
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    • v.7 no.2
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    • pp.157-164
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    • 1998
  • It has been very difficult to managing partial joint defect in any etiologies, especially in children. Unicondylar defect of the tibial condyle in children reconstructed with proximal fibular head with articular cartilage from 1995. Two kinds of transfering methods were used, peroneal artery pedicled ipsilateral fibula head transposition to defective lateral tibial condyle defect that revealed poor prognosis with gradual absorption of transposed fibular epiphysis. Free vascularized fibular head transplantation with microvascular anastomosis underwent in the case with medial condyle defect of tibia which revealed very satisfactory results. Author can conclude with these clinical experiences: 1. Tranposition without epiphyseal vesssels intact is not sufficient in fibular head osteochondral transplantation in reconstruction of tibial condyle defect. That means peroneal arterial vascular pedicle is not enough for transplanted proximal epiphysis maintains its function on articular surface and growth activity in children. 2. The anterior recurrent tibial artery is one of the most important and easy to utilizing vessel in proximal fibular epiphyseal transplantation. 3. Free vascularized fibular head transplantation is hopeful method in reconstruction of the knee joint in the patient with partial joint defect which has no effective solution in conventional methods.

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Custom-Made T-Tube Designed by 3-D Reconstruction Technique, a Preliminary Study (삼차원 재건 기술을 이용한 맞춤형 몽고메리 T-Tube의 제작에 관한 예비 연구)

  • Yoo, Young-Sam
    • Korean Journal of Bronchoesophagology
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    • v.16 no.2
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    • pp.131-137
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    • 2010
  • Background: Montgomery T-tube is widely used to maintain airway in many cases. Market-available tubes are not always fit to the trachea of each patient and need some modification such as trimming. Complications do happen in prolonged use like tracheostomy tubes. To overcome above limitations, we designed custom-made T-tube using CT data with the aid of 3D reconstruction software. Material and Method: Boundaries were extracted from neck CT data of normal person and processed by surface rendering methods. Real laryngotracheal model and tracheal inner surface-mimicking tube model were made with plaster and rubber. The main tube was designed by accumulation of circles or simple closed curves made from boundaries. Stomal tube was made by accumulation of squares due to limitation of software. Measurement data of tracheal lumen were used to custom-made T-tubes. Tracheal lumen residing portion (vertical limb) was made like circular cylinder or simple closed curved cylinder. Stomal portion (horizontal limb) was designed like square cylinder. Results: Custom made T-tube with cylindric vertical limb and horizontal limb of square cylinder was designed. Conclusion: CT data was helpful in making custom made T-tube with 3D reconstruction technique. If suitable materials are available, commercial T-tube can be printed out from 3D printers.

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