• Title/Summary/Keyword: statistical reconstruction

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Surgical Management of Comminuted Midshaft Clavicle Fractures Using Reconstruction Plate and Circumferential Wiring: Does the Circumferential Wiring Interfere with the Bone Union? (쇄골 간부 복합 골절에서 재건 금속판 및 환 강선을 이용한 수술적 치료: 환 강선이 골 유합을 방해하는가?)

  • Kim, Kyung-Tae;Shin, Chung-Shik;Park, Young-Chul;Kim, Dong-hyun;Kim, Min-Woo
    • Journal of the Korean Orthopaedic Association
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    • v.56 no.3
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    • pp.245-252
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    • 2021
  • Purpose: This study examined the radiological and clinical outcomes of internal fixation using a reconstruction plate and 21G circumferential wire in comminuted midshaft clavicular fractures. Materials and Methods: A retrospective cohort study was performed on 51 patients between 2005 and 2019. Thirty-two patients underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and 19 patients underwent surgery without a wire. The patients were assessed with the radiographic parameters, the University of California at Los Angeles (UCLA) score, and the visual analogue scale (VAS) pain score. Based on this, patients who operated without a circumferential wire were set as the control group, and the differences in bone union between the two groups were compared. Results: Thirty-two patients were followed-up for an average of 65 weeks, and 19 patients in the control group were followed-up for an average of 56 weeks. The radiological evaluation confirmed the anatomical reduction and bone union in all 32 patients. No case of nonunion was present. The UCLA score was 32.38 on average and 33.11 in the control group (p=0.395). The VAS score was 1.00 on average and 0.84 in the control group (p=0.668). A significant difference in the bony union time was observed between the group who underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and the control group (p=0.015). On the other hand, there was no statistical significance when other variables were controlled (p=0.107). Conclusion: For displaced midshaft clavicular fractures, internal fixation using a reconstruction plate and 21G circumferential wire maintained accurate anatomical reduction. The satisfactory clinical and radiological results mean that internal fixation using a reconstruction plate and 21G circumferential wire may be a good option for surgical treatment.

Terrain Geometry from Monocular Image Sequences

  • McKenzie, Alexander;Vendrovsky, Eugene;Noh, Jun-Yong
    • Journal of Computing Science and Engineering
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    • v.2 no.1
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    • pp.98-108
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    • 2008
  • Terrain reconstruction from images is an ill-posed, yet commonly desired Structure from Motion task when compositing visual effects into live-action photography. These surfaces are required for choreography of a scene, casting physically accurate shadows of CG elements, and occlusions. We present a novel framework for generating the geometry of landscapes from extremely noisy point cloud datasets obtained via limited resolution techniques, particularly optical flow based vision algorithms applied to live-action video plates. Our contribution is a new statistical approach to remove erroneous tracks ('outliers') by employing a unique combination of well established techniques-including Gaussian Mixture Models (GMMs) for robust parameter estimation and Radial Basis Functions (REFs) for scattered data interpolation-to exploit the natural constraints of this problem. Our algorithm offsets the tremendously laborious task of modeling these landscapes by hand, automatically generating a visually consistent, camera position dependent, thin-shell surface mesh within seconds for a typical tracking shot.

Measurement of 3-D Flow inside a Micro Curved-tube using Digital Micro Holographic Particle Tracking Velocimetry (디지털 Micro Holographic PTV기법을 이용한 미세 곡관 내부 3차원 유동 측정)

  • Kim, Seok;Lee, Sang-Joon
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2579-2584
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    • 2007
  • A digital micro holographic particle tracking velocimetry (HPTV) system consisting of a high-speed camera and a single laser with acoustic optical modulator (AOM) chopper was established. The digital micro HPTV system was applied to water flow in a micro curved-tube for measuring instantaneous 3-D velocity field data consecutively. The micro curved-tube is using to reproduce the dorsal aorta or utilize in various lap-on-a-chip. The temporal evolution of a three-dimensional water flow in the micro curved-tube (the curvature, ${\kappa}$=1/${\phi}$, 2/${\phi}$, 4/${\phi}$, 8/${\phi}$) of 100 ${\mu}m$ and 300 ${\mu}m$ inner diameters was obtained and mean velocity field distribution was obtained by statistical-averaging the instantaneous velocity fields.

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Refinement of Disparity Map using the Rule-based Fusion of Area and Feature-based Matching Results

  • Um, Gi-Mun;Ahn, Chung-Hyun;Kim, Kyung-Ok;Lee, Kwae-Hi
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.304-309
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    • 1999
  • In this paper, we presents a new disparity map refinement algorithm using statistical characteristics of disparity map and edge information. The proposed algorithm generate a refined disparity map using disparity maps which are obtained from area and feature-based Stereo Matching by selecting a disparity value of edge point based on the statistics of both disparity maps. Experimental results on aerial stereo image show the better results than conventional fusion algorithms in the disparity error. This algorithm can be applied to the reconstruction of building image from the high resolution remote sensing data.

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Shape From Focus Algorithm with Optimization of Focus Measure for Cell Image (초점 연산자의 최적화를 통한 세포영상의 삼차원 형상 복원 알고리즘)

  • Lee, Ik-Hyun;Choi, Tae-Sun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.3 no.3
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    • pp.8-13
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    • 2010
  • Shape form focus (SFF) is a technique that reconstructs 3D shape of an object using image focus. Although many SFF methods have been proposed, there are still notable inaccuracy effects due to noise and non-optimization of image characteristics. In this paper, we propose a noise filter technique for noise reduction and genetic algorithm (GA) for focus measure optimization. The proposed method is analyzed with a statistical criteria such as Root Mean Square Error (RMSE) and correlation.

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Position Detection of a Scattering 3D Object by Use of the Axially Distributed Image Sensing Technique

  • Cho, Myungjin;Shin, Donghak;Lee, Joon-Jae
    • Journal of the Optical Society of Korea
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    • v.18 no.4
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    • pp.414-418
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    • 2014
  • In this paper, we present a method to detect the position of a 3D object in scattering media by using the axially distributed sensing (ADS) method. Due to the scattering noise of the elemental images recorded by the ADS method, we apply a statistical image processing algorithm where the scattering elemental images are converted into scatter-reduced ones. With the scatter-reduced elemental images, we reconstruct the 3D images using the digital reconstruction algorithm based on ray back-projection. The reconstructed images are used for the position detection of a 3D object in the scattering medium. We perform the preliminary experiments and present experimental results.

Surface Reconstruction Using Statistical Techniques (통계 기법을 이용한 곡면 복원)

  • Yoon, Min-Cheol;Lee, Yun-Jin;Lee, Seung-Yong;Ivrissimtzis, Ioannis;Seide1, Hans-Peter
    • Journal of the Korea Computer Graphics Society
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    • v.11 no.2
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    • pp.47-55
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    • 2005
  • 곡면 복원이나 곡면 복원과 질은 관련이 있는 노말 추정을 하는 대부분의 방법은 결정론적인 알고리즘을 사용한다. 결정론적 알고리즘은 속도가 빠르고, 오차가 크지 않은 입력에 대해서는 좋은 질의 곡면 복원을 할 수 있다. 그러나 결정론적 방법의 특성상 이상치나 노이즈를 가진 데이터에 대해서는 안정된 복원 결과를 얻을 수 없다. 본 논문에서는 앙상블이라고 불리는 통계적인 방법을 사용해서 곡면 복원과 노말 추정을 하는 기존의 알고리즘을 개선한다. 앙상블 기법은 먼저 입력 점 집합을 무작위로 샘플링해서 점 집합의 부분집합을 만든다. 그리고 나서 만들어진 부분 집합에 독립적으로 결정론적인 알고리즘을 적용하여 결과를 얻어낸다. 마지막으로, 각각의 서로 다른 결과를 결합하여 더 우수한 최종결과를 얻어낸다. 널리 쓰이는 노말 추정 기법[11]과 Multi-level Partitions of Unity implicit [18]를 사용해서 앙상블이 효과적으로 노이즈가 많은 데이터를 처리할 수 있는 것을 보여준다.

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Effect of Dimension Reduction on Prediction Performance of Multivariate Nonlinear Time Series

  • Jeong, Jun-Yong;Kim, Jun-Seong;Jun, Chi-Hyuck
    • Industrial Engineering and Management Systems
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    • v.14 no.3
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    • pp.312-317
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    • 2015
  • The dynamic system approach in time series has been used in many real problems. Based on Taken's embedding theorem, we can build the predictive function where input is the time delay coordinates vector which consists of the lagged values of the observed series and output is the future values of the observed series. Although the time delay coordinates vector from multivariate time series brings more information than the one from univariate time series, it can exhibit statistical redundancy which disturbs the performance of the prediction function. We apply dimension reduction techniques to solve this problem and analyze the effect of this approach for prediction. Our experiment uses delayed Lorenz series; least squares support vector regression approximates the predictive function. The result shows that linearly preserving projection improves the prediction performance.

A Study on the Nonlinear Dynamics of PR Interval Variability Using Surrogate data

  • Lee, J.M.;Park, K.S.;Shin, I.S.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.27-30
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    • 1996
  • PR interval variability has been proposed as a noninvasive tool for in-vestigating the autonomic nervous system as welt as heart rate variability. The goal of this paper is to determine whether PR interval variability is generated from deterministic nonlinear dynamics. The data used in this study is a 24-hour bolter ECGs of 20 healthy adults. We developed an automatic PR interval measurement algorithm, and tested it using MIT ECG Databases. The general discriminants of nonlinear dynamics, such as, correlation dimension and phase space reconstruction are used. Surrogate data is generated from simpler linear models to have similar statistical characteristics with the original data. Nonlinear discriminants are applied to both data, and compared for any significant results. It was concluded that PR interval variability shows non-linear characteristics.

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Regional Analysis of Soft Tissue Thickness on Korean Buttocks and Application to Fasciocutaneous Flap Design

  • Kim, Do Yup;Choi, Hyun Nam;Park, Jin Hyung;Kim, Sin Rak;Kim, Hyun;Han, Yea Sik
    • Archives of Plastic Surgery
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    • v.41 no.2
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    • pp.133-139
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    • 2014
  • Background Various shapes and designs of the gluteal artery perforator flap have been used for treating sacral pressure sores and reconstructing breasts. To establish the ideal fasciocutaneous flap design for use in the gluteal area, the soft tissue thickness distribution was measured. Methods Twenty-one buttocks of adult Korean cadavers were analyzed through rectangular subfascial dissection. Each buttock was divided horizontally into 10 sections and vertically into 10 sections, and then, the thickness at the corners of the sections was measured. For the sake of comparison and statistical verification with living bodies, computed tomography (CT) images of 120 buttocks of patients were randomly selected. Five horizontal sections and 4 vertical sections were made, and the thickness at each corner was recorded. Results According to the dissection and the CT images, the area with the thinnest soft tissues in the buttock was around the posterior superior iliac spine, close to the sacral area. The thickest area was the superolateral area of the buttock, which was 3.24 times and 2.15 times thicker than the thinnest area in the studies on cadaver anatomy and the CT images, respectively. Conclusions The thickness of the soft tissues in the buttocks differed by area. The superolateral area had the thickest soft tissues, and the superomedial area had the thinnest. This study includes information on the distribution of the thickness of the gluteal soft tissues of Koreans. The outcome of this study may contribute to the design of effective local flaps for pressure sore reconstruction and free flaps for breast reconstruction.