• Title/Summary/Keyword: motion correction

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Consideration from the Viewpoint of Chiropractic Correction on the Dysfunction of Temporomandibular Joint

  • Kong, Byung Sun
    • Journal of International Academy of Physical Therapy Research
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    • v.4 no.2
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    • pp.625-632
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    • 2013
  • This study was to investigate the needs of the functional abnormality of the Temporomandibular joint. The purpose of this study was to find out basic concept for the Chiropractic-care necessity of the neuromuscular skeletal patients with functional abnormality of the temporomandibular joint. I evaluated the change of the range of motion, neck pain, headache by post xray, orthopedic test and patient's charts. The range of motion at temporomandibular joint was improved and the necessity of chiropractic care was recognized in the neuromuscular skeletal patients with having temporomandibular joint problems.

MRI Artifact Correction due to Unknown Respiratory Motion (미지 호흡운동에 의한 MRI 아티팩트의 수정)

  • 김응규
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.53-62
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    • 2004
  • In this study, an improved post-processing technique for correcting MRI artifact due to the unknown respiratory motion in the imaging plane is presented. Respiratory motion is modeled by a two-Dimensional linear expending-shrinking movement. Assuming that the body tissues are incompressible fluid like materials, the proton density per unit volume of the imaging object is kept constant. According to the introduced model, respiratory motion imposes phase error, non-uniform sampling and amplitude modulation distortions on the acquired MRI data. When the motion parameters are known or can be estimatead a reconstruction algorithm based on biliner superposition method was used to correct the MRI artifact. In the case of motion parameters are unknown, first, the spectrum shift method is applied to find the respiratory fluctuation function, x directional expansion coefficient and x directional expansion center. Next, y directional expansion coefficient and y directional expansion center are estimated by using the minimum energy method. Finally, the validity of this proposed method is shown to be effective by using the simulated motion images.

Three-Dimensional Corrective Osteotomy for Treatment of Cubitus Varus after Supracondylar Fracture of the Humerus (상완골 과상부 골절후 발생한 내반주 변형에 대한 삼차원 교정 절골술)

  • Kim Poong Taek;Ihn Joo Chul;Kyung Hee Soo;Oh Seung Hoon
    • Clinics in Shoulder and Elbow
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    • v.1 no.1
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    • pp.58-65
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    • 1998
  • Cubitus varus deformity after supracondylar fracture of the humerus in children generally includes deformities of varus, hyperextension and internal rotation. Recently almost all corrective osteotomies for treatment of the varus deformity have been limited to correction of only the varus or of the varus and hyperextension deformity. Electromyographic study has revealed unphysiological joint motion and muscle activity around the joint in elbows with cubitus varus, hyperextension and internal rotation deformity. On this basis we have successfully attempted simultaneous correction of all three deformities. The end results in ] 3 elbows have been satisfactory without any complications such as delayed union, limitation of elbow motion or nerve palsy. In conclusion, we recommend simultaneous correction of the three elements of cubitus varus deformity to restore anatomic alignment of the elbow joint.

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Development of Simplified Formulae for Added Mass of a 2-D Floating Body with a Semi-Circle Section in a Finite Water Depth (유한 수심에서 반원형 부유체의 부가질량계수 약산식 개발)

  • Koo, Weoncheol;Kim, Jun-Dong
    • Journal of Ocean Engineering and Technology
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    • v.27 no.1
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    • pp.80-84
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    • 2013
  • This study is to develop the simplified formulae for added mass coefficient of a 2-D floating body with a semi-circle section in a finite water depth. The semi-circle floating body may represent a simplified midship section transformed by Lewis form, which can be used for the ship motion analysis by strip theory. Since the added mass coefficient varies with motion frequencies and sea bottom effect, the correction factor representing the effect of water depth and frequencies is developed for accurate prediction of added mass. Using a two-dimensional numerical wave tank (NWT) technique based on the boundary element method (BEM) including sea bottom boundary the reference values of added mass are calculated to develop the correction factor. For verification and effectiveness of the formulae, the predicted added mass coefficients for various frequencies and water depth ratios are compared with the calculated values from NWT technique.

Flicker Reduction Algorithm using Gamma Correction Parameter (감마보정 요소를 이용한 동영상 플리커 제거 알고리즘)

  • Choi, Heon-Hoi;Lee, Im-Geun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.397-400
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    • 2010
  • The changing light condition of scene cause the luminance fluctuation of the captured image sequences. this artifact is called flicker, and would be easily recognized as visually unstable fluctuation. As the flicker degrades the performance of extracting useful information from image sequences, such as motion information or segmentation, it should be correction and linear flicker model. The algorithm model the flicker effects as a linear system with gain and offset parameter and estimates gain parameter with Gamma correction. The flicker reduction is performed by applying these parameters inversely th the ordinal sequences. To show the performance, we test out algorithm th the ground-truth sequences with the artificially added luminance fluctuation and real sequence with object motion.

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Fast Motion Artifact Correction Using l$_1$-norm (l$_1$-norm을 이용한 움직임 인공물의 고속 보정)

  • Zho, Sang-Young;Kim, Eung-Yeop;Kim, Dong-Hyun
    • Investigative Magnetic Resonance Imaging
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    • v.13 no.1
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    • pp.22-30
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    • 2009
  • Purpose : Patient motion during magnetic resonance (MR) imaging is one of the major problems due to its long scan time. Entropy based post-processing motion correction techniques have been shown to correct motion artifact effectively. One of main limitations of these techniques however is its long processing time. In this study, we propose several methods to reduce this long processing time effectively. Materials and Methods : To reduce the long processing time, we used the separability property of two dimensional Fourier transform (2-D FT). Also, a computationally light metric (sum of all image pixel intensity) was used instead of the entropy criterion. Finally, partial Fourier reconstruction, in particular the projection onto convex set (POCS) method, was combined thereby reducing the size of the data which should be processed and corrected. Results : Time savings of each proposed method are presented with different data size of brain images. In vivo data were processed using the proposed method and showed similar image quality. The total processing time was reduced to 15% in two dimensional images and 30% in the three dimensional images. Conclusion : The proposed methods can be useful in reducing image motion artifacts when only post-processing motion correction algorithms are available. The proposed methods can also be combined with parallel imaging technique to further reduce the processing times.

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Preceding Vehicle Detection and Tracking with Motion Estimation by Radar-vision Sensor Fusion (레이더와 비전센서 융합기반의 움직임추정을 이용한 전방차량 검출 및 추적)

  • Jang, Jaehwan;Kim, Gyeonghwan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.12
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    • pp.265-274
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    • 2012
  • In this paper, we propose a method for preceding vehicle detection and tracking with motion estimation by radar-vision sensor fusion. The motion estimation proposed results in not only correction of inaccurate lateral position error observed on a radar target, but also adaptive detection and tracking of a preceding vehicle by compensating the changes in the geometric relation between the ego-vehicle and the ground due to the driving. Furthermore, the feature-based motion estimation employed to lessen computational burden reduces the number of deployment of the vehicle validation procedure. Experimental results prove that the correction by the proposed motion estimation improves the performance of the vehicle detection and makes the tracking accurate with high temporal consistency under various road conditions.

Motion Control Algorithm Expanding Arithmetic Operation for Low-Cost Microprocessor (저가형 마이크로프로세서를 위한 연산처리 확장 모션제어 알고리즘)

  • Moon, Sang-Chan;Kim, Jae-Jun;Nam, Kyu-Min;Kim, Byoung-Soo;Lee, Soon-Geul
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.12
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    • pp.1079-1085
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    • 2012
  • For precise motion control, S-curve velocity profile is generally used but it has disadvantage of relatively long calculation time for floating-point arithmetics. In this paper, we present a new generating method for velocity profile to reduce delay time of profile generation so that it overcomes such disadvantage and enhances the efficiency of precise motion control. In this approach, the velocity profile is designed based on the gamma correction expression that is generally used in image processing to obtain a smoother movement without any critical jerk. The proposed velocity profile is designed to support both T-curve and S-curve velocity profile. It can generate precise profile by adding an offset to the velocity profile with decimals under floating point that are not counted during gamma correction arithmetic operation. As a result, the operation time is saved and the efficiency is improved. The proposed method is compared with the existing method that generates velocity profile using ring buffer on a 8-bit low-cost MCU. The result shows that the proposed method has no delay in generating driving profile with good accuracy of each cycle velocity. The significance of the proposed method lies in reduction of the operation time without degrading the motion accuracy. Generated driving signal also shows to verify effectiveness of the proposed method.

A Modified Technique for the Correction of Funnel Chest (함몰흉 교정의 변형수기)

  • 이상호
    • Journal of Chest Surgery
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    • v.33 no.10
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    • pp.806-811
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    • 2000
  • Background : The authors have modified the method of Ravitch technique. Material and Method ; This technique was applied to 6 patients out of 18 patients who underwent corrective surgery from May 1987 to July 1999. The technique is quite different from that of Ravitch. We did not divide the intercostal muscle bundles from the laterals of sternum and the Akin's struts were placed retrosternally crossing the chest horizontally to prevent flail motion during immediate post-operative period and retraction of the sternum afterwards. Anterior sternal osteotomy instead of the posterior one was performed for the latest 3 cases which made operative procedure more simple and easy. The struts were removed one year later. Result : Compared to the hospital stay of the patients who received standard Ravitch method that of the six cases who received our modification was definitely shortened from 13.1 days to 8.3 days(p<0.0000). Flail motion was not noted in any patient and chest wall stability was obtained more easily with this technique. Conclusion : Our modification is recommendable for correction of funnel chest in regards to shorter operation time better chest wall stability shorter hospital stay and less complication.

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Applications of the wavelet transform in the generation and analysis of spectrum-compatible records

  • Suarez, Luis E.;Montejo, Luis A.
    • Structural Engineering and Mechanics
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    • v.27 no.2
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    • pp.173-197
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    • 2007
  • A wavelet-based procedure to generate artificial accelerograms compatible with a prescribed seismic design spectrum is described. A procedure to perform a baseline correction of the compatible accelerograms is also described. To examine how the frequency content of the modified records evolves with time, they are analyzed in the time and frequency using the wavelet transform. The changes in the strong motion duration and input energy spectrum are also investigated. An alternative way to match the design spectrum, termed the "two-band matching procedure", is proposed with the objective of preserving the non-stationary characteristics of the original record in the modified accelerogram.