• Title/Summary/Keyword: MOTION ANALYSIS

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Development of a Dynamic Response Analysis Method of Tension Leg Platforms in Waves (인장 계류식 해양구조물의 동적응답 해석법의 개발)

  • 구자삼;이창호;홍봉기
    • Journal of Ocean Engineering and Technology
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    • v.7 no.1
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    • pp.133-146
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    • 1993
  • A numerical procedure is described for predicting the motion and structural responses of tension leg platforms (TLPs) in waves. The developed numerical approach is based on combination of a three dimensional source distribution method and the dynamic response analysis method, in which the superstructure of TLPs is assumed flexible instead of the rigid body assumption used in usual two-step analysis method, proposed by Yoshida et. al. .The hydrodynamic interactions among TLP members, such as columms and pontoons, are included in the motion and structural analyses. Numerical results are compared with the experimental and numerical ones, which are obtained in the literature, of the motion and structural responses of a TLP in waves. The results of comparison confirmed the validity of the proposed approach.

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Motion analysis for Home Surveillance of the Aged who Lives Alone based on Video Images (비디오 기반의 독거노인 위급 상황 탐지를 위한 행동 분석)

  • Kim, Young-Baek;Rhee, Sang-Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.6
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    • pp.537-641
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    • 2007
  • In this paper, motion analysis algorithm is presented for home surveillance of the aged who lives alone. For the first step, we acquire images from a camera. To enhance the image, we use median filtering and binarize it to reduce processing time. And then morphological operations are performed to remove small blobs and small holes. At the forth step, blobs are analysed to extracts tor foreground region. Then, motions are predicted from these images by using optical tlow technique, and the predicted motion data are refined by comparing our cardboard models so as to judge behavior pattern.

Dynamic Analysis of Rectangular Liquid Storage Containers Considering Fluid-Structure Interaction effects (유체-구조물 상호작용 효과를 고려한 직사각형 단면의 수조구조물의 동적 해석)

  • 박장호;권기준
    • Journal of the Korean Society of Safety
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    • v.15 no.3
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    • pp.96-101
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    • 2000
  • The effects of internal fluid motion have to be considered in the analysis of liquid storage containers. Therefore this thesis developed a three-dimensional boundary element-finite element method for the analysis of rectangular liquid storage containers. The irrotational motion of inviscid and incompressible ideal fluid is modeled by using boundary elements and the motion of structure by finite elements. Coupling is performed by using compatibility and equilibrium conditions along the interface. Dynamic response characteristics of rectangular liquid storage containers such as sloshing motion, hydrodynamic pressure, displacement by fluid-structure interaction are investigated.

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Modal Analysis of Constrained Multibody Systems Undergoing Constant Accelerated Motions

  • Park, Dong-Hwan;Yoo, Hong-Hee
    • Journal of Mechanical Science and Technology
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    • v.18 no.7
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    • pp.1086-1093
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    • 2004
  • The modal characteristics of constrained multibody systems undergoing constant accelerated motions are investigated in this paper. Relative coordinates are employed to derive the equations of motion, which are generally nonlinear in terms of the coordinates. The dynamic equilibrium position of a constrained multibody system needs to be obtained from the nonlinear equations of motion, which are then linearized at the dynamic equilibrium position. The mass and the stiffness matrices for the modal analysis can be obtained from the linearized equations of motion. To verify the effectiveness and the accuracy of the proposed method, two numerical examples are solved and the results obtained by using the proposed method are compared with those obtained by analytical and other numerical methods. The proposed method is found to be accurate as well as effective in predicting the modal characteristics of constrained multibody systems undergoing constant accelerated motions.

Realtime Face Tracking using Motion Analysis and Color Information (움직임분석 및 색상정보를 이용한 실시간 얼굴추적)

  • Lee, Kyu-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.5
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    • pp.977-984
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    • 2007
  • A realtime face tracking algorithm using motion analysis from image sequences and color information is proposed. Motion area from the realtime moving images is detected by calculating temporal derivatives first, candidate pixels which represent face region is extracted by the fusion filtering with multiple color models, and realtime face tracking is performed by discriminating face components which includes eyes and lips. We improve the stability of face tracking performance by using template matching with face region in an image sequence and the reference template of face components.

A Study on the Auto Closing Systems Motion Analysis of Door in Smoke Control Zone (제연구역 출입문의 자동폐쇄장치 운동해석에 관한 연구)

  • Lee, Dong-Myung
    • Fire Science and Engineering
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    • v.24 no.3
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    • pp.106-112
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    • 2010
  • This study carried out the motion analysis of auto closing systems as basis study for development of auto closing systems for door in smoke control zone. This study established process of auto closing systems and analysis theory based on kinematics mechanism thesis and mechanism modelling of auto closing control units. And this study established engineering data construction and a source technology that can design each element of auto closing control units that choose closing force units through motion analysis simulation based on analysis theory. Therefore, it can give flexibility and elasticity of auto closing units development from this study. Also, it sees that can ready control means and technological countermeasure of smoke by development of auto closing units and secure high reliancity and stability of smoke control systems.

Dynamic Analysis of ROV Cable with the Coupling of Ship Motion (선체 운동을 고려한 ROV 케이블의 연성 동력학 해석)

  • Cho, Kyu-Nam;Song, Ha-Cheol
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.94-98
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    • 2003
  • Remotely Operated Vehicle. ROV is a new concept equipment being made to replace the manned systems for investigating the deep sea environment. This paper presents the dynamic cable response during ROV launching considering the coupling effects of ship motion. By the harmonic response analysis, the variations of cable tensions were obtained. Harmonic forces in head/beam sea states were calculated by the concept of relative acceleration which obtained by ship motion analysis.

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The Biomecanical Analysis of Taekwondo Footwear (태권도화의 운동역학적 분석)

  • Jin, Young-Wan;Kawk, Yi-Sub
    • Korean Journal of Applied Biomechanics
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    • v.17 no.3
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    • pp.105-114
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    • 2007
  • The purpose of this study was to compare the biomechanical difference of barefoot and two types taekwondo footwear. which will provide scientific data to coaches and players, to further prevent injuries and to improve each players skills. How to an effect on human body which studied a kinematics and kinetics from 8 college students during experiments. This study imposes several conditions by barefoot and two types of taekwondo footwear ran under average $2.56{\pm}0.21\;m$/sec by motion analysis, ground reaction force and electromyography that used to specific A company. First of all, motion analysis was caused by achilles tendon angle, angle of the lower leg, angle of the knee. The result of comparative analysis can be summarized as below. Motion analysis showed that statically approximates other results from achilles tendon angle (p<.01), initial ankle angle(p<.05), initial sole angle(p<.001) and barefoot angle(p<.001). Ground reaction force also showed that statically approximates other results from impact peak timing (p.001), Maximum loading rate(p<.001), Maximum loading rate timing (p<.001) and impulse of first 20 percent (p<.001). showed that averagely was distinguished from other factors, and did not show about that.

A Study of Symmetry in the Patterns of Muscle Coordination and Interjoint Coordination in the Upper Limb Activity Among Subjects With Stroke (뇌졸중 환자의 상지에서 근육협응 패턴과 관절협응 패턴의 유사성에 관한 연구)

  • Lee, Jung-Ah;Shin, Hwa-Kyung;Chung, Yi-Jung;Cho, Sang-Hyun
    • Physical Therapy Korea
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    • v.13 no.1
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    • pp.54-60
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    • 2006
  • This study aimed to compare movement patterns of shoulder joints between the right and left symmetry in stroke patients and control subjects. This study proposes use of the voluntary response index (VRI) calculated from quantitative analysis of surface electromyographic (sEMG) and motion data recorded during voluntary movement as a feeding task. The VRI is comprised of two numeric values, one derived from the total muscle activity recorded for the voluntary motor task (magnitude), and the other from the sEMG distribution across the recorded muscles with the similarity index (SI). Five stroke patients and five age-matched healthy controls were recruited. Feeding motion was performed using the provided spoon five times with rests taken on a chair in between tasks. EMG data were digitized and analyzed on the basis of the root mean square (RMS) envelope of activity. The average amplitude of responses was calculated. Responsiveness and clinically meaningful levels of discrimination between stroke patients and control for EMG magnitude and SI were determined. The similarity index of the results from two successive examinations of both sides apart for stroke patients and control subjects were .86 and .95 in motion analysis and .84 and .99 in electromyographic analysis. The SI of sEMG data and motion data was significantly correlated in stroke patients. The data suggest that SI is a sensitive program for comparing and analyzing the symmetry of muscle activity and motion in both sides. This analysis method has a clinical value in grading muscular activity and movement impairment after brain injury.

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A Frequency Domain Motion Response Analysis of Substructure of Floating Offshore Wind Turbine with Varying Trim (부유식 해상풍력발전기 하부구조물의 종경사각에 따른 주파수 영역 운동응답 분석)

  • In-hyuk Nam;Young-Myung Choi;Ikseung Han;Chaeog Lim;Jinuk Kim;Sung-chul Shin
    • Journal of Navigation and Port Research
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    • v.48 no.3
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    • pp.155-163
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    • 2024
  • As the demand for reducing carbon emissions increases, efforts to reduce the usage of fossil fuels and research on renewable energy are also increasing. Among the various renewable energy harvesting techniques, the floating offshore wind turbine has several advantages. Compared to other technologies, it has fewer installation limitations due to interference with human activity. Additionally, a large wind turbine farm can be constructed in the open ocean. Therefore, it is important to conduct motion analysis of floating offshore wind turbines in waves during the initial stage of conceptual design. In this study, a frequency motion analysis was conducted on a semi-submersible type floating offshore wind turbine. The analysis focused on the effects of varying trim on the motion characteristics. Specifically, motion response analysis was performed on heave, roll, and pitch. Natural period analysis confirmed that changing the trim angle did not significantly affect the heave and pitch motions, but it did have a regular impact on the roll motion.