• Title/Summary/Keyword: shape reconstruction

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The "Sombrero-Shape" Super-Thin Pedicled ALT Flap for Complete Scrotal Reconstruction Following Fournier's Gangrene

  • Sapino, Gianluca;Gonvers, Stephanie;Cherubino, Mario;di Summa, Pietro G.
    • Archives of Plastic Surgery
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    • v.49 no.3
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    • pp.453-456
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    • 2022
  • When the scrotal sac is entirely debrided following a Fournier gangrene, testes exposure poses unique challenges for the reconstructive surgeon. Despite the anterolateral thigh (ALT) flap is considered a workhorse in such context, aesthetic results are often suboptimal because of the lack of natural ptosis and patchwork appearance. We describe the use of a super-thin pedicled ALT flap for total scrotal reconstruction, modified according to a peculiar flap design and inset technique. A 42-year-old man was referred to our department for delayed total scrotal reconstruction 8 months after a Fournier gangrene extensive debridement. A super-thin pedicled ALT flap from the right thigh was designed: in the central portion of the ALT, a lateral skin paddle extension was marked to guarantee adequate posterior anchorage during insetting and ptosis of the scrotal sac. This particular flap arrangement has inspired the name "sombrero" as the shape is akin to the famous hat. No secondary refinements were needed, and the patient showed satisfying aesthetic and functional results at 12 months' follow-up. The ALT flap design "sombrero" modification proposed in this article can improve scrotum cosmesis and patient satisfaction in a single-stage single-flap procedure.

Estimation of 3-D Symmetric Shapes Using Shape-from-Shading Technique (Shape-from-Shading 기술을 이용한 대칭물체의 3차원 형상 예측)

  • Hong, Soon-Hwa;Hong, Dae-Hie
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.12
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    • pp.2503-2510
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    • 2002
  • Since the first shape-form-shading technique was developed by Horn in the early 1970s, many different approaches have been continuously emerging in the past three decades. Some of them improve existing techniques, while others are completely new approaches. Using the image reflectance equation, they estimate the 3-D shape of an object utilizing adequate constraints. Each algorithm applies different constraints such as brightness, smoothness, and integrability to solve the shape-from-shading problem. Especially for symmetric objects, a symmetry constraint is proposed to improve the performance of existing shape-from-shading algorithm in this paper. The symmetry constraint is imposed to a conventional algorithm and then the improvement in the performance of 3-D shape reconstruction is proved by quantitatively comparing the depth and gradient errors.

Shape Adaptive Searching Region to Find Focused Image Points in 3D Shape Reconstruction (3차원 형체복원에 있어서 측정면에 적응적인 초점화소 탐색영역 결정기법)

  • 김현태;한문용;홍민철;차형태;한헌수
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.77-77
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    • 2000
  • The shape of small or curved object is usually reconstructed using a single camera by moving its lens position to find a sequence of the focused images. Most conventional methods have used a window with fixed shape to test the focus measure, which resulted in a deterioration of accuracy. To solve this problem, this paper proposes a new approach of using a shape adaptive window. It estimates the shape of the object at every step and applies the same shape of window to calculate the focus measure. Focus measure is based on the variance of the pixels inside the window. This paper includes the experimental results.

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A 3-D Tube Reconstruction based on Axis Alignment of Multiple Laser Scanning (배관측 정렬 방법을 이용한 다중레이저 스캐닝 기반의 3차원 배관복원)

  • Baek, Seung-Hae;Park, Soon-Yong;Kim, Seung-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.11
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    • pp.1159-1167
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    • 2011
  • A novel 3D tube scanning technique is proposed. The proposed tube scanning technique is developed for a special tube inspection module which consists of four line-lasers and one camera. Using the scanning module, we can reconstruct the 360 degree shapes of the inner surfaces of a cylindrical tube. From an image frame captured by the camera, we reconstruct a partial tube model based on four laser triangulations. Then by aligning such partial models with respect to a reference tube axis, a complete 3D shape of the tube is reconstructed. The tube axis in each reconstructed frame is aligned with a 3D Euclidean transformation to the reference axis. Several experiments show that the proposed method can align multiple tube axes very accurately and reconstruct 3D shapes of a tube with very low shape distortion.

Reconstruction of polygonal prisms from point-clouds of engineering facilities

  • Chida, Akisato;Masuda, Hiroshi
    • Journal of Computational Design and Engineering
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    • v.3 no.4
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    • pp.322-329
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    • 2016
  • The advent of high-performance terrestrial laser scanners has made it possible to capture dense point-clouds of engineering facilities. 3D shape acquisition from engineering facilities is useful for supporting maintenance and repair tasks. In this paper, we discuss methods to reconstruct box shapes and polygonal prisms from large-scale point-clouds. Since many faces may be partly occluded by other objects in engineering plants, we estimate possible box shapes and polygonal prisms and verify their compatibility with measured point-clouds. We evaluate our method using actual point-clouds of engineering plants.

East 3-Dimensional Shape Reconstruction Using Phase-Shifting Grating Projection Moire Method (위상천이 영사식 모아레법을 이용한 고속 3차원 형상복원)

  • 최이배;구본기;정연구
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1998.11a
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    • pp.111-115
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    • 1998
  • A phase-shifting projection moire method particularly intended for high-speed three-dimensional shape reconstruction of diffuse objects is presented. Emphasis is on realization of phase-shifting fringe analysis in projection moire topography using a set of line grating pairs designed to provide different phase shifts in sequence. Further a time-integral fringe capturing scheme is devised to remove undesirable high frequency original grating patterns in real-time without time-consuming software image processing. Finally the performances of the proposed method are discussed with measurement results.

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Face Image Compression using Generalized Hebbian Algorithm of Non-Parsed Image

  • Kyung Hwa lee;Seo, Seok-Bae;Kim, Daijin;Kang, Dae-Seong
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.847-850
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    • 2000
  • This paper proposes an image compressing and template matching algorithm for face image using GHA (Generalized Hebbian Algorithm). GHA is a part of PCA (Principal Component Analysis), that has single-layer perceptrons and operates and self-organizing performance. We used this algorithm for feature extraction of face shape, and our simulations verify the high performance for the proposed method. The shape for face in the fact that the eigenvector of face image can be efficiently represented as a coefficient that can be acquired by a set of basis is to compress data of image. From the simulation results, the mean PSNR performance is 24.08[dB] at 0.047bpp, and reconstruction experiment shows that good reconstruction capacity for an image that not joins at leaning.

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A Study on the Impact Force Reconstruction (충격력 재현에 관한 연구)

  • 조창기;이규섭;류봉조;이종원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.949-953
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    • 1996
  • Force shape control for impact test is required in order to simulate dynamic reponse of structures which is subjected to impact force. In this paper, the mechanisms of contact and impact force generation are analyzed and tested with a simple test equipment. It was carried out for the pre-design of impact force reconstruction apparatus.

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The Use of the Internal Mammary Vessel Perforator as a Recipient Vessel for Free TRAM Breast Reconstruction (유리 횡복직근피판술을 이용한 유방의 재건에서 수혜부 혈관으로 내유방혈관 천공지의 사용)

  • Park, Myong-Chul;Lee, Jung-Hoon;Chung, Jae-Ho;Lee, Sung-Hun
    • Archives of Reconstructive Microsurgery
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    • v.10 no.2
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    • pp.105-110
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    • 2001
  • Breast reconstruction is an aesthetically critical procedure and should be peformed to match the opposite breast in shape, contour, and position. Many methods were introduced to reconstruct the breast with autogenous tissue. But, free tissue transfer for breast reconstruction has become common method. The transverse rectus abdominis myocutaneous flap technique has been a widely accepted method of breast reconstruction after mastectomy, since the first introduction of free abdominoplasty flap in 1979. In breast reconstruction with a free flap the selection of suitable recipient vessels remains one of the most critical decision for surgeon. The most common recipient site for free flap breast reconstruction is the axillar system. But, the use of the axillary system as a recipient site limits flap movement and flexibility in breast shaping. The use of internal mammary vessels as a recipient site be able to achieve ideal breast symmetry, but that technique require the rib resection. The selection of suitable recipient vessels is most important for successful free tissue transfer. We have performed breast reconstruction with TRAM flaps anastomozed to the internal mammary vessel perforator. We came to the conclusion that this vessel perforator is useful as a recipient site in cases of immediate breast reconstruction with free TRAM flap.

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