• Title/Summary/Keyword: center of rotation

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Correlation analysis between rotation parameters and attitude parameters in simulated satellite image

  • Yun, Young-Bo;Park, Jeong-Ho;Yoon, Geun-Won;Park, Jong-Hyun
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.553-558
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    • 2002
  • Physical sensor model in pushbroom satellite images can be made from sensor modeling by rotation parameters and attitude parameters on the satellite track. These parameters are determined by the information obtained from GPS, INS, or star tracker. Provided from satellite image, an auxiliary data error is connected directly with an error of rotation parameters and attitude parameters. This paper analyzed how obtaining satellite images influenced errors of rotation parameters and attitude parameters. furthermore, for detailed analysis, this paper generated simulated satellite image, which was changed variously by rotation parameters and attitude parameters of satellite sensor model. Simulated satellite image is generated by using high-resolution digital aerial image and DEM (Digital Elevation Model) data. Moreover, this paper determined correlation of rotation parameter and attitude parameters through error analysis of simulated satellite image that was generated by various rotation parameters and attitude parameters.

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Estimation of Rotation Center and Rotation Angle for Real-time Image Stabilization of Roll Axis. (실시간 회전영상 안정화를 위한 회전중심 및 회전각도 추정 방법)

  • Cho, Jae-Soo;Kim, Do-Jong
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.153-155
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    • 2004
  • This paper proposes a real-time approach on the rotational motion estimation and correction for the roll stabilization of the sight system. This method first estimates a rotation center by the least-mean square algorithm based on the motion vectors of some feature points. And, then, a rotation angle is searched for a best matching block between a reference block image and seccessive input images using MPC(maximum pixel count) matching criterion. Finally, motion correction is performed by the bilinear interpolation technique. Various computer simulations show that the estimation performance is good and the proposed algorithm is a real-time implementable one to the TMS320C6415(500MHz) DSP.

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A Study on the Measurement of Relative Rotation of Center Pivot in Power Car of KTX (고속열차 동력차의 센터피봇 상대 회전각 계측에 관한 연구)

  • Seo Sung-Il;Jeong Wu-Jin
    • Journal of the Korean Society for Railway
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    • v.9 no.3 s.34
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    • pp.277-281
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    • 2006
  • The center pivot in the power car of KTX carries the traction force of the motor bogie to the carbody. The damage to the center pivot due to failure of swivel joint causes a serious hazard of the train. To prevent the hazard, information on the relative motion between bogie and carbody is necessary. In this paper, a method to measure the relative rotation of the center pivot is proposed and an actual test to verify the method and safety is conducted. The test results show that the rotation of the center pivot is within the allowable limit and the damage due to the relative motion doesn't take place.

Effect of Substrate Rotation on the Phase Evolution and Microstructure of 8YSZ Coatings Fabricated by EB-PVD

  • Park, Chanyoung;Choi, Seona;Chae, Jungmin;Kim, Seongwon;Kim, Hyungtae;Oh, Yoon-Suk
    • Journal of the Korean Ceramic Society
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    • v.53 no.1
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    • pp.81-86
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    • 2016
  • The effect of substrate rotation speed on the phase forming behavior and microstructural variation of 8 wt% yttria ($Y_2O_3$) stabilized $ZrO_2$ (8YSZ) coatings as a thermal barrier coating has been investigated. 8YSZ coatings with $100{\sim}200{\mu}m$ thickness were deposited by electron beam-physical vapor deposition onto a super alloy (Ni-Cr-Co-Al) substrate with a bond coating (NiCo-CrAlY). The width of the columnar grains of the 8YSZ coatings increased with increasing substrate rotation speed from 1 to 30 rpm at a substrate temperature range of $900{\sim}950^{\circ}C$. In spite of the different growth behaviors of coatings with different substrate rotation speeds, the phases of each coating were not changed remarkably. Even after post heat treatments with various conditions of the coated specimens fabricated at 20 rpm, only a change of color was noticeable, without any remarkable change in the phase or microstructure.

Effect of Pediatric Integrative Manual Therapy, a Novel Mobilization with Facilitation Movement Technique, on Congenital Muscular Torticollis after Cervical Rotation and Head angle: A Case Report (선천성 근성 사경에 대한 새로운 촉진 기법을 이용한 소아 통합 도수치료적용 후 경추각도의 변화와 머리각도 변화: 단일사례연구)

  • Seung-hyoek Song;Gue-jung Hwang;Tae-gyu Seo;Jae-deung Kim;Won-jeong Whang
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.29 no.2
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    • pp.77-91
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    • 2023
  • Background: Congenital muscular torticollis results in reduced head mobility, such as cervical rotation, due to the abnormal size and contraction of the sternocleidomastoid muscle. Korea Pediatric integrative manual therapy and stretching are recommended to improve head rotation upper cervical spine mobility. Therefore, in this study, the effect of the new PIMT was investigated. Methods: The patient is a 3.5 month-old diagnosed with congenital muscular torticollis (CMT). Due to the limitation of head rotation and cervical spine rotation and flexion mobility, the child visited a rehabilitation center and after diagnosis, Pediatric integrative manual therapy (PIMT) treatment was performed five times a week for a total of 15 weeks. The child's head rotation and flexion limitation and plagiocephaly were evaluated. Results: In conclusion, this study shows that compared to other treatments, PIMT approach is a more effective treatment for improving head rotation and cervical limitation for range of motion in CMT infants. Conclusion: PIMT approach was effective in improving cervical rotation and Head lateral flexion mobility and plagiocephaly in CMT patients.

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Factors Affecting Tibial Tuberosity-Trochlear Groove Distance in Recurrent Patellar Dislocation

  • Prakash, Jatin;Seon, Jong-Keun;Ahn, Hyeon-Woon;Cho, Kyu-Jin;Im, Chae-Jin;Song, Eun Kyoo
    • Clinics in Orthopedic Surgery
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    • v.10 no.4
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    • pp.420-426
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    • 2018
  • Background: The tibial tuberosity-trochlear groove (TT-TG) distance is used to determine the necessity of tibial tubercle osteotomy. We conducted this study to determine the extent to which each of the tibial tuberosity lateralization, trochlear groove medialization, and knee rotation angle affects the TT-TG distance in both normal and patella dislocated patients and thereby scrutinize the rationale for tuberosity transfer based on the TT-TG distance. Methods: Retrospective analysis of rotational profile computed tomography was done for patella dislocated and control group patients. Femoral anteversion, tibial torsion, knee rotation angle, tuberosity lateralization, and trochlear groove medialization were assessed in all patients. Relationship of these parameters with the TT-TG distance was investigated to evaluate their effects on the TT-TG distance. Results: We observed that the patellar dislocation group, compared to the control group, had increased TT-TG distance (mean, 19.05 mm vs. 9.02 mm) and greater tuberosity lateralization (mean, 64.1% vs. 60.7%) and tibial external rotation in relation to the femur (mean, $7.9^{\circ}$ vs. $-0.81^{\circ}$). Conclusions: Tuberosity lateralization and knee rotation were factors affecting patellar dislocation. These factors should be considered in addition to the TT-TG distance to determine the need for tibial tubercle osteotomy in patients with patellar dislocation.

Rotation Control of Shoulder Joint During Shoulder Internal Rotation: A Comparative Study of Individuals With and Without Restricted Range of Motion

  • Min-jeong Chang;Jun-hee Kim;Ui-jae Hwang;Il-kyu Ahn;Oh-yun Kwon
    • Physical Therapy Korea
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    • v.31 no.1
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    • pp.72-78
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    • 2024
  • Background: Limitations of shoulder range of motion (ROM), particularly shoulder internal rotation (SIR), are commonly associated with musculoskeletal disorders in both the general population and athletes. The limitation can result in connective tissue lesions such as superior labrum tears and symptoms such as rotator cuff tears and shoulder impingement syndrome. Maintaining the center of rotation of the glenohumeral joint during SIR can be challenging due to the compensatory scapulothoracic movement and anterior displacement of the humeral head. Therefore, observing the path of the instantaneous center of rotation (PICR) using the olecranon as a marker during SIR may provide valuable insights into understanding the dynamics of the shoulder joint. Objects: The aim of the study was to compare the displacement of the olecranon to measure the rotation control of the humeral head during SIR in individuals with and without restricted SIR ROM. Methods: Twenty-four participants with and without restricted SIR ROM participated in this study. The displacement of olecranon was measured during the shoulder internal rotation control test (SIRCT) using a Kinovea (ver. 0.8.15, Kinovea), the 2-dimensional marker tracking analysis system. An independent t-test was used to compare the horizontal and vertical displacement of the olecranon marker between individuals with and without restricted SIR ROM. The statistical significance was set at p < 0.05. Results: Vertical displacement of the olecranon was significantly greater in the restricted SIR group than in the control group (p < 0.05). However, no significant difference was observed in the horizontal displacement of the olecranon (p > 0.05). Conclusion: The findings of this study indicated that individuals with restricted SIR ROM had significantly greater vertical displacement of the olecranon. The results suggest that the limitation of SIR ROM may lead to difficulty in rotation control of the humeral head.

A Study on the Rotation Center of the Different Shape of Root (치근형태에 따른 회전점에 관한 연구)

  • Lee, Ho-Yong;Um, Young-Bae;Lee, Kae-Song;Choi, Kwang-Chul
    • The Journal of the Korean dental association
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    • v.11 no.11
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    • pp.735-737
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    • 1973
  • This study is to determine the exact position of tipping rotation center of root. The method of measurement is to record by means of dial gauge. The different shapes of root of lower second premolar are named as smooth type, tapered type, and curved type. The followings are the result ; 1. The tipping rotation center of the teeth varies with he shape of roots. 2. The rotation center of the root is placed apical one third portion upon roots in the smooth shape of roots, one half portion of roots in the taper shape of roots and below the apical one-third of root in curve shape.

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A Study on the Behavior of Welded Connections (용접 연결부의 거동에 관한 연구)

  • 안주옥;윤영만
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.10a
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    • pp.145-151
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    • 1994
  • Welded connections have been designed on basis of allowable stresses, wherein the response to loading is assumed to be totally elastic. This is the vector analysis method, which resolves the stresses determined from the direct stress formula and the torsion formula into a vector combination to obtain a solution. It has been known that this method gives conservative answers and typically a very high factor of safety. An analytical method based on the Instantaneous Center of Rotation has been developed which predicts the ultimate strength of an eccentically loaded fillet welded connection. The method of Instantaneous Center of Rotation results in weld resistance capacities greater than the vector analysis method, by recognizing the variation in fillet weld strength with respect to the direction of the applied loading and actual load-deformation response of elemental fillet welds. The procedure of numerical analysis is iterative and complex. The relations between vector analysis method and the method of Instantaneous Center of Rotation on eccentrical distance subjected to variation of load direction are presented in this paper. Considering of the effects on configuration of weld groups, the method of Instantaneous Center of Rotation are provided a more exact results of the numerical analysis.

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Visualization of Rotational Flow for Chamber Size of a 2×2 Microfluidic Centrifuge (마이크로 유체 원심분리기의 챔버 크기에 따른 회전 유동 가시화)

  • Jeon, Hyeong Jin;Kwon, Bong Hyun;Kim, Dae Il;Go, Jeung Sang
    • Journal of the Korean Society of Visualization
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    • v.10 no.3
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    • pp.25-29
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    • 2012
  • This paper introduces a new parameter to design the $2{\times}2$ microfluidic centrifuge with single flow rotation positioned at the center of microchamber. The dimensional centrifugal acceleration momentum flux which is defined as the interfacial momentum flux divided by distance from the center of the chamber explains the flow rotation and its threshold provides a reference to expect single flow rotation. Through the numerical and experimental visualization of the flow rotation, the number and position of flow rotation in the $2{\times}2$ microfluidic centrifuge were examined. At a channel width of $50{\mu}m$ and chamber width of $250{\mu}m$, single flow rotation was obtained over at a Reynolds number of 300, while at a channel width of $100{\mu}m$ and chamber width of $500{\mu}m$, single flow rotation did not appear. The numerical analysis showed that the threshold centrifugal acceleration momentum flux to obtain single flow rotation was $3500kg/m{\cdot}s^2$.