• 제목/요약/키워드: Surface reconstruction

검색결과 575건 처리시간 0.046초

실린더형 쌍곡면 반사체 카메라 광각영상 복원 (Reconstruction of Wide FOV Image from Hyperbolic Cylinder Mirror Camera)

  • 김순철;이수영
    • 로봇학회논문지
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    • 제10권3호
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    • pp.146-153
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    • 2015
  • In order to contain as much information as possible in a single image, a wide FOV(Field-Of-View) imaging system is required. The catadioptric imaging system with hyperbolic cylinder mirror can acquire over 180 degree horizontal FOV realtime panorama image by using a conventional camera. Because the hyperbolic cylinder mirror has a curved surface in horizontal axis, the original image acquired from the imaging system has the geometrical distortion, which requires the image processing algorithm for reconstruction. In this paper, the image reconstruction algorithms for two cases are studied: (1) to obtain an image with uniform angular resolution and (2) to obtain horizontally rectilinear image. The image acquisition model of the hyperbolic cylinder mirror imaging system is analyzed by the geometrical optics and the image reconstruction algorithms are proposed based on the image acquisition model. To show the validity of the proposed algorithms, experiments are carried out and presented in this paper. The experimental results show that the reconstructed images have a uniform angular resolution and a rectilinear form in horizontal axis, which are natural to human.

Extended medial sural artery perforator free flap for groin and scrotal reconstruction

  • Teven, Chad M.;Yu, Jason W.;Zhao, Lee C.;Levine, Jamie P.
    • Archives of Plastic Surgery
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    • 제47권4호
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    • pp.354-359
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    • 2020
  • The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap that has been used successfully in the reconstruction of defects across the body. In specific cases, it may prove superior to more commonly used options (e.g., anterolateral thigh flap and radial forearm free flap). Historically, a disadvantage of the MSAP flap is the relatively small surface area it provides for reconstruction. We recently encountered a patient with extensive pelvic injuries from prior trauma resulting in significant scarring and contracture of the groin, tethering of the penis, and loss of the scrotum and one testicle. The patient was unable to achieve erection from tethering and his remaining testicle had been buried in the thigh. In considering the reconstructive options, he was not a suitable candidate for a thigh-based or forearm-based flap. An extended MSAP flap measuring 25 cm×10 cm was used for resurfacing of the groin and pelvis as well as for the formation of a neoscrotum. This report is the first to document an MSAP flap utilized for simultaneous groin resurfacing and scrotoplasty. Additionally, the dimensions of this flap make it the largest recorded MSAP flap to date.

Calibration of Structured Light Vision System using Multiple Vertical Planes

  • Ha, Jong Eun
    • Journal of Electrical Engineering and Technology
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    • 제13권1호
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    • pp.438-444
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    • 2018
  • Structured light vision system has been widely used in 3D surface profiling. Usually, it is composed of a camera and a laser which projects a line on the target. Calibration is necessary to acquire 3D information using structured light stripe vision system. Conventional calibration algorithms have found the pose of the camera and the equation of the stripe plane of the laser under the same coordinate system of the camera. Therefore, the 3D reconstruction is only possible under the camera frame. In most cases, this is sufficient to fulfill given tasks. However, they require multiple images which are acquired under different poses for calibration. In this paper, we propose a calibration algorithm that could work by using just one shot. Also, proposed algorithm could give 3D reconstruction under both the camera and laser frame. This would be done by using newly designed calibration structure which has multiple vertical planes on the ground plane. The ability to have 3D reconstruction under both the camera and laser frame would give more flexibility for its applications. Also, proposed algorithm gives an improvement in the accuracy of 3D reconstruction.

원위 요골 악성 종양의 광범위 절제술 후 혈행성 유리 비골 두 이식을 이용한 수근관절 재건술 (Reconstruction of Wrist Joint Using Vascularized Free Fibular Head Graft After the Wide Tumor Excision of Distal Radius)

  • 송석환;이윤민
    • Archives of Reconstructive Microsurgery
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    • 제20권1호
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    • pp.82-88
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    • 2011
  • Vascularized free fibula head transfer is an established method for reconstruction of long bone defects of the upper limb involving the distal radius or the proximal humerus. For the wrist following tumor resection, in cases of resection of the radial articular surface, three reconstructive options are possible: 1. fibular head transfer to replace the radial joint surface, 2. fixation of the fibula to the scaphoid and lunate, 3. complete wrist fusion. The decision on the type of the operation depends on the amount of the resection and the remained normal anatomical structures, and also the necessity of function of the wrist in the future. The authors believe that the vascularized free fibula head graft is a safe and reliable method for reconstructing the upper limb, especially for patients with a defect of the distal radius, and report the operative methods, donor vascular consideration, complications, and functional result after this operation.

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비정합조건 하의 슬라이딩 모드 관측기를 이용한 강인 제어 (Robust control using the sliding mode observer in the presence of unmatched uncertainties)

  • 한상철;박인규;함운철
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.334-334
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    • 2000
  • In this paper, sliding mode observer design principles based on the equivalent control approach are discussed for the systems which may not satisfy the matching conditions. We propose a new approach for designing a sliding observer and the proof of the stability of the state reconstruction error system for time-invariant systems using the Lyapunov method. The reaching time to the sliding surface, the sliding dynamics of the system, the stability of the reconstruction error system via Lyapunov method, sufficient conditions for the existence of the sliding mode are studied.

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Allograft reconstruction for large parosteal osteoma of the clavicle: a case report

  • Shin, Donghyup;Kim, Wonseok;Park, Jungho
    • Clinics in Shoulder and Elbow
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    • 제24권4호
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    • pp.261-264
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    • 2021
  • A large parosteal osteoma arising on the surface of the right clavicle of a 39-year-old male patient was suspected preoperatively as a parosteal osteosarcoma. The lesion was treated with wide resection and allograft reconstruction. In this case report, we discuss the accurate diagnosis and appropriate surgical treatment for unusual clavicular tumors.

역 비고유치 BEM을 사용한 소리 굽쇠의 외부 음향 홀로그래픽 재현 (Exterior Acoustic Holography Reconstruction of a Tuning Fork using Inverse Non-singular BEM)

  • Jarng, Soon-Suck;Lee, Je-Hyeong
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.335.2-335
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    • 2002
  • Non-singular boundary element method (BEM) codes are developed in acoustics application. The BEM code is then used to calculate unknown boundary surface normal displacements and surface pressures from known exterior near field pressures. And then the calculated surface normal displacements and surface pressures are again applied to the BEM in forward in order to calculate reconstructed field pressures. (omitted)

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표층화분의 WA-PLS 분석을 통한 한반도 남동부지역 홀로세 고기온 복원 (Reconstruction of Paleo-Temperature During the Holocene Using WA-PLS Analysis of Modern Pollen From the Surface Soil in the Southeastern Part of the Korean Peninsula)

  • 윤순옥;황범진;황상일
    • 한국지형학회지
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    • 제24권4호
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    • pp.13-25
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    • 2017
  • To reconstruct the paleo-temperature quantitatively and to overcome limitation of traditional qualitative pollen analysis, this study was performed pollen analysis using the modern surface soil at Yulha-dong, Gimhae-si of southeastern part of Korean peninsula. Canonical Correspondence Analysis(CCA) was done to identify the most important environment variable about composition of modern surface pollen sample. Also, Weighted Average-Partial Least Square(WA-PLS) was analyzed to obtain modern surface pollen-temperature transfer function. The transfer function was applied to the results of qualitative fossil pollen analysis at Yulha-dong, Gimhae-si, Sampyung-ri, Ulsan-si and Taewha-dong, Ulsan-si. Therefore, the paleo-temperature was reconstructed during the Holocene since 6,200 yr BP. According to the results of the research, it is $1{\sim}2^{\circ}C$ lower than the current average annual temperature at the study area in 6,200 yr BP, since then it increased to the same level to the current temperature and decreased again until 2,600 yr BP. From the 2,600 yr BP, the temperature was fluctuated to the present.

An algorithm for ultrasonic 3-dimensional reconstruction and volume estimation

  • Chin, Young-Min;Park, Sang-On;Woo, Kwang-Bang
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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    • pp.791-796
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    • 1987
  • In this paper, an efficient algorithm to estimate the volume and surface area from ultrasonic imaging and a reconstruction algorithm to generate three-dimensional graphics are presented. The computing efficiency is Improved by using the graph theory and the algorithm to determine proper contour points is performed by applying several tolerances. The search for contour points is limited by the change in curvature in order to provide an efficient search of the minimum cost path. These algorithms are applied to a selected mathematical model of ellipsoid. The results show that the measured value of the volume and surface area for the tolerances of 1.0005, 1.001 and 1.002 approximate to the measured values for the tolerance of 1.000 resulting in small errors. The reconstructed 3-dimensional Images are sparse and consist of larger triangular tiles between two cross sections as tolerance is increased.

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