• 제목/요약/키워드: internal force

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Stress Variation Characteristics of a High-Pressure Hose with Respect to Wire Braid Angle (강선의 편조각도에 따른 고압호스의 응력변화 특성)

  • Kim, H.J.;Koh, S.W.;Kim, B.T.
    • Journal of Power System Engineering
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    • v.9 no.3
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    • pp.71-78
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    • 2005
  • A high-pressure hose includes rebar layers of the synthetic fiber such as nylon or a steel wire to control internal pressure. The hose assembly is manufactured through the swaging process to clamp the hose into the metal fittings. Usually, the hose behavior is affected by the resultant of the longitudinal and circumferential forces produced by the internal pressure. The rebar layers can appear the most ideal rebar effect when they are arranged to the same direction as the resultant force. The braid angle applied in the rebar layers is an important factor in determining ultimate burst pressure and overall hose life. Failure can occur on the contacted parts of a hose with the metal fittings under severe operating conditions such as high pressure and temperature of the inner fluid. In this paper, the mechanical behavior between the hose and the metal fittings during the swaging process and the stress variation characteristics of a high-pressure hose under a constant applied pressure are analyzed with respect to the braid angle of steel wire using the finite element method.

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Optimal Excitation Trajectories for the Dynamic Parameter Identification of Industrial Robots by Using Combined Model (통합모델과 최적 경로설계를 통한 산업용 로봇 동적 매개변수 규명)

  • Park, K.J.
    • Journal of Power System Engineering
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    • v.12 no.2
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    • pp.55-61
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    • 2008
  • This paper discusses the advantages of using Fourier-based periodic excitation and of combining internal and external models in dynamic robot parameter identification. Internal models relate the joint torques or forces with the motion of the robot; external models relate the reaction forces and torques on the bedplate with the motion data. This combined model allows to combine joint torque/force and reaction torque/force measurements in one parameter estimation scheme. This combined model estimation will yield more accurate parameter estimates, and consequently better predictions of actuator torque, which is shown by means of a simulated experiment on a CRS A465 industrial robot.

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Vibration Analysis of Rotor Systems Using Finite Dynamic Elements (동적 유한요소에 의한 회전축 계의 진동 해석)

  • 양보석;황형섭
    • Journal of KSNVE
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    • v.7 no.3
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    • pp.467-475
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    • 1997
  • A rotor-bearing system has been investigated, including internal damping and axial torque using finite dynamic elements. A procedure is presented for dynamic modeling of rotor-bearing system which consist of finite dynamic shaft elements, rigid disk, and bearing and seal. A finite dynamic element model including the effects of rotatory inertia, gyroscopic moments, axial force, and axial torque is developed using the frequency dependent shape function. The natural whirl speeds, stability, and unbalance response of rotor system are calculated on several cases and compared with the conventional finite elements.

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Analyses Thermal Stresses for Microaccelerometer Sensors using SOI Wafer(I) (SOI웨이퍼를 이용한 마이크로가속도계 센서의 열응력해석(I))

  • Kim, O.S.
    • Journal of Power System Engineering
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    • v.5 no.2
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    • pp.36-42
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    • 2001
  • This paper deals with finite element analyses of residual stresses causing popping up which are induced in micromachining processes of a microaccelerometer sensors. The paddle of the micro accelerometer sensor is designed symmetric with respect to the direction of the beam. After heating the tunnel gap up to 100 degree and get it through the cooling process and the additional beam up to 80 degree and get it through the cooling process. We learn the thermal internal stresses of each shape and compare the results with each other, after heating the tunnel gap up to 400 degree during the Pt deposition process. Finally we find the optimal shape which is able to minimize the internal stresses of microaccelerometer sensor. We want to seek after the real cause of this pop up phenomenon and diminish this by change manufacturing processes of microaccelerometer sensor by electrostatic force.

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An easily attainable and effective bilateral control for teleoperation

  • Son, J. B.;Youm, Y.;Chung, W.K.;Jeong, K. W.
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.404-407
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    • 1995
  • Teleoperating system has been developed for several decades, and many control schemes for it have been suggested. But the implementation for real application needs very simple but effective controller. In this paper, an advanced control scheme for this purpose is suggested, which is the combination of a modified internal model controller and variable filter for force reflection. And we verify the effectiveness of the proposed scheme through the experiment. We use PUMA-560 as the slave robot, which is operated by velocity servo loop with geared motor. Both the responses of free motion and contact motion are shown.

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The Effects of Ohotang on the rat tracheal smooth muscle contracted with acetylcholine (오호탕(五虎湯)이 백서(白鼠)의 호흡기계(呼吸器系)에 미치는 영향(影響))

  • Kim, Ho-Soon;Han, Sang-Whan
    • The Journal of Internal Korean Medicine
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    • v.15 no.1
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    • pp.227-237
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    • 1994
  • These studies were carried out to investigate the effects of Ohotang water extract on the inhibitory contractile action of acetylcholine in control rat. The results of these were as follows; 1. Contractile force of acetylcholine from trachea smooth muscle in control rat was significantly inhibited by Ohotang. 2. Dose-response of acetylcholine pretreated Ohotang in control rat was significantly inhibited. 3. Inhibitory contractile action of acetylcholine pretreated propranolol in control rat was significantly inhibited by Ohotang. 4. Contractile force of acetylcholine pretreated indomethacin from trachea smooth muscle in control rat was not significantly changed. 5. Inhibitory contractile action of acetylcholine pretreated methylene blue in control rat was not significantly changed.

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The effects of Macmundongtang on the Rat tracheal smooth muscle contracted with acetylcholine (맥문동탕(麥門冬湯)이 백서(白鼠)의 기관지(氣管支) 평골근(平滑筋)에 미치는 영향(影響))

  • Kim, Hyun-Young;Han, Sang-Whan
    • The Journal of Internal Korean Medicine
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    • v.15 no.2
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    • pp.240-248
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    • 1994
  • These studies were carried out to investigate the effects of Macmundongtang extract on the inhibitory contractile action of acetylcholine in control rat. The results of these studies were as follows: 1. Contractile force of acetylcholine from tracheal smooth muscle in control rat was significantly inhibited by Macmundongtang. 2. Inhibition contractile action of acetylcholine pretreated ACH $ED_{50}$ in control rat was significantly changed. 3. Dose-response of acetylcholine pretreated Macmundongtang in control rat was not significant. 4. Inhibitory contractile action of acetylcholine pretreated propranolol in control rat was not significantly changed by Macmundongtang. 5. Inhibitory contractile action of acetylcholine pretreated methylene blue in control rat was significantly changed. 6. Contractile force of acetylcholine pretreated indomethacin from trachea smooth muscle in control rat was not significantly inhibited by Macmundongtang.

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Damping performance Analysis for an Electronically Contralled Shock Absorber (연속 가변형 충격흡수기의 감쇠성능 해석)

  • 박재우;이동락;백운경
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.2
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    • pp.192-201
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    • 2001
  • Analyzing internal structure, flow rate and dynamic behavior characteristics of electronically controlled shock absorber, damping performance limit is identified to comprise the two reciprocal characteristics of ride comfort and handling safety. Regardless of its lower performance than the active suspension control system, the semi-active suspension control system has been taking interest because of its absolutely higher performance than passive suspension system. Since the pervious studies have been concentrated mostly on analytic aspect and survey on the internal structure of the shock absorber remain insufficient, the main discourse of this paper is focused on analyzing the nonlinear shock absorber which varies the damping force of semi-active suspension system and the dynamic characteristics of the solenoid valve, a sort of pressure valve, and proposing the design factors of importance.

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APPLICATION OF FIBRIN ADHESIVE IN DISK REPLACEMENT AFTER MENISCECTOMY (관절원판 절제술후 중간삽입물 고정에 피브린 접착제의 응용)

  • Chung, Hoon;Kim, Hyeong-Keun;Kim, Young-Soo;Yu, Ki-Jun;Ahn, Byoung-Guen
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.14 no.3
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    • pp.175-184
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    • 1992
  • Meniscectomy is indicated for the internal derangement of disk with perforation and gross morphological changes, nonreactive to conservative treatment procedures. After the meniscectomy, permanent disk replacement can be followed. Variable materials have been introduced for disk replacement. Of them, relatively harder replacing materials should have been fixed with surgical wire only. This poor fixation method provide inadequate retentive force and conclusively can be attributed to postoperative noise, poor prognosis. We tried to use biocompatible fibrin adhesive in order to obtain additional fixation force in the method above mentioned and treated two patients with the late stage of internal derangement of disk In both cases, satisfactory results were obtained.

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Compressive strength degrdation model of Ultra high strength under high temperature (고온가열을 받는 초고강도 콘크리트의 압축강도저하 모델 제안)

  • Choe, Gyeong-Choel;Kim, Gyu-Yong;Yoon, Min-Ho;Lee, Young-Wook;Lee, Bo-Kyeong;Kim, Hong-Seop
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.26-27
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    • 2014
  • Study on high temperature properties of concrete and internal force estimation of structural member subjected to high temperature mainly applied high temperature strength model based on experimental results with concrete under 40MPa. However, it is reported that degradation of internal force at high temperature and spalling of ultra high strength concrete are higher than that of normal strength concrete. Therefore, this study attempts to propose compressive strength degradation model which is suitable to ultra high strength concrete comparing to existing model by evaluating high temperature properties of ultra high strength concrete.

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