• Title/Summary/Keyword: Motion Comparison

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Three dimensional finite element analysis of static deflections of a machine tool structures (3차원 유한요소 모델링을 통한 공작기계 구조의 정적 변형도 해석)

  • 김현석;이수정;정광섭;이대길
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.638-643
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    • 1993
  • The three dimensional finite element models for the basic deflection of linear motion guides and ball screws were developed. Form the comparison of the results calculated by the finite element method with those by the experiment, it was proved that the modeling method might be applied to real machine tool structures. Form the structural analysis of the headstock of the machine tool, it was found that the static stiffness was calculated within 6.5% error

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Position Control of a Redundant Flexible Manipulator (여유자유도 유연 매니퓰레이터의 위치제어)

  • 김진수
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.3
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    • pp.83-89
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    • 2001
  • In this paper, we discuss the vibration suppression control of spatial redundant flexible manipulators through pseudo-inversed of Jacobian. In order to verify our method, the experiments are performed for PTP(Point To Point) motion of spa-tial flexible manipulators(1) with no redundancy(2) with one redundant DOF(degree of freedom). Finally, a comparison between these results is presented to show the performance of out approach.

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Simulation of a Non-Directional Wave Spectrum Analysis with Welch's Method

  • Park, Soo-Hong
    • Journal of information and communication convergence engineering
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    • v.6 no.2
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    • pp.146-149
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    • 2008
  • Simulation and signal conditioning on the time domain surface elevation records are conducted to verify the proposed Welch's method in non-directional ocean wave spectrum analysis. These spectrum data are further conditioned to provide wave characteristic that better describe the sea states. Comparison of significant wave height and zero crossing period between the proposed method and a reference toolkit are presented.

Simplified Seismic Response Analysis of a RC Bridge (철근콘크리트 교량의 단순화된 내진응답해석)

  • 이도형;전종수;박대효
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.949-954
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    • 2003
  • In this paper, simplified modeling approach describing the hysteretic behavior of reinforced concrete columns is discussed. The inelastic response of a reinforced concrete column or pier subjected to cyclic deformation reversals or earthquake ground motion is evaluated by use of lumped hysteretic representation. For this purpose, the hystertic model under axial force variation is developed and implemented into a nonlinear finite element analysis program. The analytical predictions obtained with the new formulation are compared with test results and reveal accuracy and applicability in terms of strength and stiffness. In addition, comparison between results with and without axial force variation stresses the importance of the proposed approach.

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Seismic Response Analysis of Wood Structure Using Nonlinear Time History Method (비선형 시간 이력법에 의한 목조 가옥의 지진응답해석)

  • 김재관
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.04a
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    • pp.212-219
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    • 1998
  • Dynamic analyses are performed for the wood structure modeled as a SDOF hysteretic system. The hysteresis model presented is a modified version of Takeda model. The comparison between the results of numerical simulation and the experimental results show good agreements in overall tendencies. The response of wood structure subjected to artificially generated earthquakes considering site effects is studied. It appears that the response is very strongly influenced by the intensity and the frequency contents of the ground motion.

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A Study on the Surface Control of a Magnetic Fluid (자성유체의 표면제어에 관한 연구)

  • Shin, J.O.;Rhee, E.J.;Park, M.K.
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.65-69
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    • 2001
  • In this study, the deformation of the free surface motion of a magnetic fluid for the change in electromagnetic force is discussed. In case, magnetic fluid in characteristics of fluid adjusted to the opposite direction of the gravity direction. Thus, the device of a magnetic fluid proposed the complete zero-leakage Sealing and the surface actuator. The device of surface deformation as well comparison between numerical simulation and experiments as will be presented.

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Longitudinal Vibration Analysis of an Axially Moving Material by Using the Assumed Modes Method (가정모드법을 이용한 축방향으로 이동하는 연속체의 종진동 해석)

  • 정진태;허진욱;한창수
    • Journal of KSNVE
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    • v.10 no.1
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    • pp.138-143
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    • 2000
  • Longitudinal vibration of an axially moving material is investigated by using the assumed modes method. To circumvent a difficulty in choosing the comparison functions which satisfy the boundary conditions, the assumed modes method is adopted by which equations of motion are discretized. Based on the discretized equations, the complex eigenvalue problem is solved and then the effects of the translating velocity on the natural frequencies and modes are analyzed.

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Vibrational behaviour of higher-order cylindrical shells

  • Longjie Zhang
    • Advances in concrete construction
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    • v.15 no.2
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    • pp.137-147
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    • 2023
  • Dynamic analysis of a shear deformable shell is investigated with accounting thickness stretching using Hamilton's principle. Through this method, the total transverse is composed into bending, shearing and stretching portions, in which the third part is responsible for deformation along the transverse direction. After computation of the strain, kinetic and external energies, the governing motion equations are derived using Hamilton's principle. A comparative study is presented before presentation of full numerical results for confirmation of the formulation and methodology. The results are presented with and without thickness stretching to show importance of the proposed theory in comparison with previous theories without thickness stretching.

Effect of Visual and Palpation Feedback on Muscle Activity of Gluteus Maximus and Motion of Pelvic Rotation during Clam Exercise (크램 운동 시 시각-촉진 되먹임이 큰볼기근 활성도와 골반 회전에 미치는 영향)

  • Koh, Eun-Kyung;Jung, Do-Young
    • The Journal of Korean Physical Therapy
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    • v.25 no.5
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    • pp.337-342
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    • 2013
  • Purpose: This study was conducted in order to determine the effect of visual and tactile feedback on muscle activity of the gluteus maximus (Gmax) and abdominal muscles and the motion of pelvic rotation during performance of clam exercise (CE). Methods: Thirteen subjects without low back pain were recruited for this study. Each subject was instructed to perform the CE without and with feedback. The subjects were instructed to keep pelvic from rotating backwards by palpating the ASIS and monitoring the pelvic movement by themselves during performance of CE with feedback. The electromyographic (EMG) activities of Gmax and abdominal muscles were collected using surface EMG. Angles of pelvic rotation were measured using a 3-dimensional motion-analysis system. Paired t-tests were used for comparison of EMG activities in each muscle and the angle of pelvic rotation. Results: The EMG activities of all abdominal muscles were not significant between CM without and CM with feedback (p>0.05). The EMG activity of Gmax was significantly greater in CM with feedback compared with CM without feedback (without vs. with feedback; 14.2% vs. 20.7%MVIC) (p<0.05). The angle of pelvic rotation was significantly less in CM with feedback compared with CM without feedback (without vs. with feedback; $15.3^{\circ}$ vs. $10.8^{\circ}$ ) (p<0.05). Conclusion: Therefore, these findings suggest that CM with the visual and tactile feedback is effective in activation of the Gmax and correcting of the uncontrolled lumbopelvic rotation during CE.

The Effect of Elastic Therapeutic Taping on Lower Limb Kinematics during a Cross Cutting Movement from Landing in Subjects with Chronic Ankle Instability (탄력 테이핑이 만성 발목 불안정 환자의 착지 후 방향 전환 시 하지 관절 움직임에 미치는 영향)

  • Jo, Tae-Seong;Kim, Tack-Hoon;Choi, Houng-Sik;Roh, Jung-Suk
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.4
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    • pp.1-9
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    • 2017
  • PURPOSE: This study investigated the effect that an elastic therapeutic taping treatment given to patients with chronic ankle instability had on the vertical ground reaction force, center of pressure, and range of motion in the ankle, knee and hip joints, during a Cross-cutting movement from landing. METHODS: This study analyzed 12 able-bodied adults and 12 patients with chronic ankle instability classified by using the Cumberland tool in the motion analysis laboratory, Hanseo University. The experiment was conducted under two conditions elastic taping and no treatment. In order to analyze the difference between the groups. An independent t-test was performed at p>.01. RESULTS: Plying an elastic therapeutic taping to the patients with chronic ankle instability significantly decreased the range of joint motion in the inversion of the ankle joint, the flexion of the knee joint, and the flexion and internal rotation of the hip joint during a cross-cutting movement from landing in comparison with the able-bodied adults p<.01. This restriction in the range of motion decreased the center-of-pressure trajectory length of patients with chronic ankle instability p>.01. CONCLUSION: An elastic therapeutic taping treatment given to patients with chronic ankle instability causes ankle stability to increase during a cross-cutting movement from landing.