• Title/Summary/Keyword: Alignment Reconstruction

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Application of the GPS Data Simplification Methods for Railway Alignments Reconstruction (철도 선형 복원을 위한 GPS 데이터 단순화 방법의 적용)

  • 정의환
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.22 no.1
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    • pp.63-71
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    • 2004
  • This research is to reconstruction of railway alignment using GPS data, an investigation is made on the method of optimum simplification for reduction of unnecessary linear data, improve the accuracy by using four simplification algorithms among the methods. By applying two measured of displacement between observed data and it's simplification methods have been evaluated. The results showed that the complexities of lines is not practical to investigate simplification algorithms, the Douglas-Peucker method produced a little displacement between observed data and it's simplification. Its by using the Douglas-Peucker method to observed linear GPS data in railway track, design elements of horizontal alignment have been calculated. Then we could know that obtain the good results fur reconstruction of alignment elements through the methods and algorithns of this study.

Alignment of Tilted TEM Images for 3D Reconstruction (3차원 복원을 위하여 특정 투사각도에서 획득한 TEM 영상열의 정렬)

  • Lee, Jun-Ho;Lee, Ji-Ho;Kim, Dong-Sik
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.207-208
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    • 2007
  • In this paper, the tilted image sequence, which is obtained the transmission electron microscopy (TEM) for a 3D reconstruction, is aligned based on the fiducial marker method. A direct correlation method is also conducted between adjacent tilted images for the performance comparison. Using real TEM tilted images, we can successfully perform the alignment.

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Reconstruction of Neural Circuits Using Serial Block-Face Scanning Electron Microscopy

  • Kim, Gyu Hyun;Lee, Sang-Hoon;Lee, Kea Joo
    • Applied Microscopy
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    • v.46 no.2
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    • pp.100-104
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    • 2016
  • Electron microscopy is currently the only available technique with a spatial resolution sufficient to identify fine neuronal processes and synaptic structures in densely packed neuropil. For large-scale volume reconstruction of neuronal connectivity, serial block-face scanning electron microscopy allows us to acquire thousands of serial images in an automated fashion and reconstruct neural circuits faster by reducing the alignment task. Here we introduce the whole reconstruction procedure of synaptic network in the rat hippocampal CA1 area and discuss technical issues to be resolved for improving image quality and segmentation. Compared to the serial section transmission electron microscopy, serial block-face scanning electron microscopy produced much reliable three-dimensional data sets and accelerated reconstruction by reducing the need of alignment and distortion adjustment. This approach will generate invaluable information on organizational features of our connectomes as well as diverse neurological disorders caused by synaptic impairments.

Application of the Terrestrial Photogrammetric for Railway Alignments Reconstruction (철도 선형 복원을 위한 지상사진측량의 적용)

  • Lee Jong-Chool;Park Woon-Yong;Kang In-Jun;Jang Ho-Sik
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.265-269
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    • 2006
  • In this study, horizontal alignment of railroad obtained by digital photogrammetry method. The two-dimensional horizontal alignment was reappeared by camera calibration and digital image data. This method's result showed more satisfactory value than existing survey method in horizontal alignment of railroad. Hereafter, this method would be a appropriate method lot the decision of railroad facility' position in small rural area and construction of DB for the design of alignment.

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Normal Range of Humeral Head Positioning on the Glenoid on Magnetic Resonance Imaging: Validation through Comparison of Computed Tomography and Magnetic Resonance Imaging

  • Kim, Jung-Han;Min, Young-Kyoung
    • Clinics in Shoulder and Elbow
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    • v.21 no.4
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    • pp.186-191
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    • 2018
  • Background: To determine the normal range of humeral head positioning on magnetic resonance imaging (MRI). Methods: We selected normal subjects (64 patients; group A) to study the normal range of humeral head positioning on the glenoid by MRI measurements. To compare the MRI measurement method with the computed tomography (CT), we selected group B (70 patients) who underwent both MRI and CT. We measured the humeral-scapular alignment (HSA) and the humeral-glenoid alignment (HGA). Results: The HSA in the control group was $1.47{\pm}1.05mm$, and the HGA with and without reconstruction were $1.15{\pm}0.65mm$ and $1.03{\pm}0.59mm$, respectively, on MRI. In the test group, HSA was $2.67{\pm}1.47mm$ and HGA with and without reconstruction was $1.58{\pm}1.16mm$ and $1.49{\pm}1.08mm$, on MRI. On CT, the HSA was $1.72{\pm}1.01mm$, and HGA with and without reconstruction were $1.54{\pm}0.96mm$ and $1.59{\pm}0.93mm$, respectively. HSA was significantly different according to image modality (p=0.0006), but HGA was not significantly different regardless of reconstruction (p=0.8836 and 0.9234). Conclusions: Although additional CT scans can be taken to measure decentering in patients with rotator cuff tears, reliable measurements can be obtained with MRI alone. When using MRI, it is better to use HGA, which is a more reliable measurement value based on the comparison with CT measurement (study design: Study of Diagnostic Test; Level of evidence II).

Reconstruction of Alignment elements in Railway using GPS (GPS 기법을 이용한 철도 선형제원의 복원)

  • Jeong, Eui-Hwan;Lee, Nam-Soo
    • Proceedings of the KSR Conference
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    • 2003.10b
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    • pp.123-128
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    • 2003
  • The first design elements of horizontal alignment are very important things for improvement or movement in Railway. When the design elements are lost or damaged, it is necessary to recalculation. In this paper, an investigation is made on the method of representation of horizontal alignment as a result of design element using GPS method. The results show that northing calculated about $2\~10$ meters and easting calculated about $0\~7$ meters between calculated and design data in center points.

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Systematic Review of Reciprocal Changes after Spinal Reconstruction Surgery : Do Not Miss the Forest for the Trees

  • Kim, Chang-Wook;Hyun, Seung-Jae;Kim, Ki-Jeong
    • Journal of Korean Neurosurgical Society
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    • v.64 no.6
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    • pp.843-852
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    • 2021
  • The purpose of this review was to synthesize the research on global spinal alignment and reciprocal changes following cervical or thoracolumbar reconstruction surgery. We carried out a search of PubMed, EMBASE, and Cochrane Library for studies through May 2020, and ultimately included 11 articles. The optimal goal of a truly balanced spine is to maintain the head over the femoral heads. When spinal imbalance occurs, the human body reacts through various compensatory mechanisms to maintain the head over the pelvis and to retain a horizontal gaze. Historically, deformity correction has focused on correcting scoliosis and preventing scoliotic curve progression. Following substantial correction of a spinal deformity, reciprocal changes take place in the flexible segments proximal and distal to the area of correction. Restoration of lumbar lordosis following surgery to correct a thoracolumbar deformity induces reciprocal changes in T1 slope, cervical lordosis, pelvic shift, and lower extremity parameters. Patients with cervical kyphosis exhibit different patterns of reciprocal changes depending on whether they have head-balanced or trunk-balanced kyphosis. These reciprocal changes should be considered to in order to prevent secondary spine disorders. We emphasize the importance of evaluating the global spinal alignment to assess postoperative changes.

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.

The Changes of Patellofemoral Alignment after Anterior Cruciate Ligament Reconstruction (전방 십자 인대 재건술후 슬개-대퇴 관절 선열의 변화)

  • Hahn Sung-Ho;Yang Bo-Kyu;Yi Seung-Rim;Chung Shun-Wook;Kwon Gi-Doo
    • Journal of the Korean Arthroscopy Society
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    • v.4 no.2
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    • pp.128-133
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    • 2000
  • Purpose : To compare the changes of the patellar height, patellofemoral alignment and subjective symptom and to compare the effects of patellar tendon harvest after anterior cruciate ligament(ACL) reconstruction using autograft and allograft. Materials and Method : ACL reconstruction was performed on 87 patients who were followed up for minimum 1 year. The group I was 52 patients who were operated with bone-patellar tendon-bone autograft and the group II was 35 patients who were operated with bone-patellar tendon-bone allograft and achilles tendon allograft. At the time of follow-up, the authors evaluated the patellar height by Blackburne-Peel method, Merchant congruence angle, Lateral patellofemoral angle and subjective symptoms were assessed. Results : The patellar heights were significantly decreased from 0.86 preoperatively to 0.80 postoperatively in the group I and from 0.87 preoperatively to 0.83 postoperatively in the group II. There were no significant differences in the lateral patellofemoral angles between the both groups but in the Merchant congruence angle, significant differences were observed in the both groups, from$-1.43^{\circ}$ preoperatively to-$5.43^{\circ}$ postoperalively in the group I and from$-1.53^{\circ}$ preoperatively to$-3.65^{\circ}$ postoperatively in the group II. Conclusion : After ACL reconstruction, the patellofemoral alignment was changed and this kind of changes may be caused by multiple factorials such as harvest of autografts, ACL reconstruction itself, and quadriceps muscle atrophy.

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Posterior and Posterolateral Instability of Knee Joint (후방 및 후외측 불안정성 슬관절)

  • Lee, Dong-Chul
    • Journal of the Korean Arthroscopy Society
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    • v.7 no.2
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    • pp.127-136
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    • 2003
  • Posterolateral instability of the knee occurs more commonly in association with an injury to anterior and posterior cruciate ligament and combined injuries are severe injuries that result in significant functional instability and articular cartilage degeneration. Reconstruction of the anterior and posterior cruciate ligament without an appropriate treatment of posterolateral corner injury result in failure of the reconstructed cruciate ligaments. Meticulous physical examinations, imaging studies, lower limb alignment and gait pattern should be evaluated. Acute grade III isolated or combined injury of the posterolateral corner is best treated within three weeks by direct repair, or augumentation, or reconstruction. The appropriate surgical method or combined methods are selected among the several methods of posterior and posterolateal reconstruction, and all injuried posterolateral and cruciate ligament structures are anatomically reconstructed simultaneously or by stages. If a varus alignment and varus thrust is disclosed in chronic posterolateral instability of knee, soft tissue reconstructions laterally are highly unlikely to be able to correct tile problem. It is appropriate that valgus osteotomy should be done before soft tissue reconstruction and reevaluate the posterolateral instability about 6 months later.

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