• Title/Summary/Keyword: position function

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Association of Scapular Acromion-table Distance with Upper Quarter Y-balance Test and Trapezius Muscle Activity Patterns

  • Jeongwoo Jeon
    • Physical Therapy Rehabilitation Science
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    • v.13 no.3
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    • pp.285-293
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    • 2024
  • Objective: This study investigated whether the acromion-table distance is associated with trapezius activity patterns during shoulder movements and the upper quarter Y-balance test (UQYBT). Additionally, it was to determine the correlation between upper, middle, and lower trapezius muscle activity. Design: Cross-sectional study Methods: Twenty-eight healthy young males participated in this study. Outcome measures included: (1) acromion-to-table distance, which assesses the scapular position, (2) trapezius muscle activity during shoulder flexion and abduction, and (3) the UQYBT, a measure of upper extremity function measured. Results: A significant negative correlation was observed between the acromion-table distance and the inferior-lateral direction reach distance of UQYBT (r=-0.499 and p=0.007). There were negative correlations between the upper and lower trapezius during shoulder flexion (r=-0.901, p < 0.001) and abduction (r=-0.661, p < 0.001), respectively. There was also a negative correlation between the upper and middle trapezius during shoulder abduction (r=-0.466, p=0.012). Conclusions: The acromion-table distance was related to the UQYBT. Anterior tilt of the scapula and limited range of motion of the shoulder may occur as the acromion-table distance increases. In addition, the acromion-table distance reflects the pectoralis minor muscle shortening, suggesting that the scapula position or the pectoralis minor shortening may influence the upper limb function. Therefore, these factors should be considered when assessing upper limb function using the UQYBT.

A Calibration Technique and its Error Analysis for the Position of Seabed Sonar Target (해저고정 소나표적의 위치교정기법과 오차해석)

  • 이상국;이용곤
    • Journal of the Korea Institute of Military Science and Technology
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    • v.6 no.3
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    • pp.15-21
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    • 2003
  • This paper contains a precise calibration technique for the position of seabed acoustic target and theoretical error analysis of calibration results. The target is deployed on seabed as a standalone transponder. The purpose of target is performing accuracy test for active sonar as well as position calibration itself. For the position calibration, relative range between target and test vessel should be measured using target's transponder function. The relative range data combined with vessel position can be converted into a estimated position of target by the application of nonlinear LSE method. The error analysis of position calibration was divided into two stages. One is for relative range estimator and the other for target position estimator. Numerical simulations for position calibration showed good matching between results and developed CRLB.

On analysis of nonlinear impedance force control for robot manipulators (로봇의 비선형 임피던스 힘제어에 대한 연구)

  • Jung, Seul;Lee, Ji-Hong
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.560-563
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    • 1997
  • The conventional impedance control has been known to have the following problems: it has lack of specifying force directly and unknown environment stiffness has to be known priori in order to specify the reference trajectory. In this paper, new impedance force control that can control a desired force directly under unknown stiffness is proposed. A new nonlinear impedance function is developed based on estimation of unknown stiffness from force and position measurements. The nonlinear characteristics of the proposed impedance function are analyzed based on unknown environment position. Simulation studies with robot manipulator are carried out to test analytical results.

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PMSM Sensorless Speed Control Using a High Speed Sliding Mode Observer (고속 슬라이딩모드 관측기를 이용한 PMSM 센서리스 속도제어)

  • Son, Ju-Beom;Kim, Hong-Ryel;Seo, Young-Soo;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.3
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    • pp.256-263
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    • 2010
  • The paper proposes a sensorless speed control strategy for a PMSM (Permanent Magnet Synchronous Motor) based on a new SMO (Sliding Mode Observer), which substitutes a signum function with a sigmoid function. To apply robust sensorless control of PMSM against parameter fluctuations and disturbance, the high speed SMO is proposed, which estimates the rotor position and angular velocity from the back EMF. The low-pass filter and additional position compensation of the rotor are used to reduce the chattering problem commonly found in sliding mode observer with signum function, which becomes possible by applying the sigmoid function with the control of a switching function. Also the proposed sliding mode observer with the sigmoid function has better efficiency than the conventional sliding mode observer since it adjusts the observer gain by variable boundary layer and estimates the stator resistance. The stability of the proposed sliding mode observer is verified by the Lyapunov second method in determining the observer gain. The validity of the proposed high speed PMSM sensorless velocity control has been demonstrated by real experiments.

A PI-PD Controller Design for the Position Control of a Motor (전동기 위치 제어를 위한 PI-PD 제어기 설계)

  • Jang, Ju-Hyeong;Kim, Sang-Hoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.1
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    • pp.60-66
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    • 2017
  • This paper presents the design of a proportional-integral (PI)-proportional-derivative (PD) position controller without using a speed controller in motor drive systems. Unlike the existing PI-PD position controller design methods, the proposed controller is designed by reducing the entire position control system to a second-order transfer function. Thus, the gain values for the PI-PD position controller can be determined easily by a given bandwidth of the position controller. The PI-PD position controller designed by the proposed method is adopted for position control in an interior permanent magnet synchronous motor drive system to confirm the validity of the proposed design method. The effectiveness of the proposed design method is confirmed through experiments.

Comparison of the Effects of Abdominal Bracing Exercises and Abdominal Hollowing Exercises on Lumbar Flexibility and Pulmonary Function in Healthy Adults

  • Kim, Kyung-bin;Chon, Seung-chul
    • Physical Therapy Korea
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    • v.24 no.4
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    • pp.68-76
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    • 2017
  • Background: Abdominal bracing exercise (ABE) and abdominal hollowing exercise (AHE) improve the lumbar flexibility and pulmonary function in various patients, yet the efficacy of ABE or AHE have not yet been evaluated. Objects: The purpose of this study was to compare the lumbar flexibility and pulmonary function during both ABE and AHE in healthy adults. Methods: The study included 40 healthy adults, who were randomly divided into the experimental group and control group, each with 20 subjects. All subjects performed ABE (experimental group) and AHE (control group). The lumbar flexibility such as trunk flexion test (sitting and standing position) and schober test and pulmonary function such as the spirometer including forced vital capacity (FVC) and force expiratory volume in one second ($FEV_1$) and chest circumference measurement (middle and lower chest) were measured, respectively. Two-way repeated analysis of variance was used to compare the lumbar flexibility and pulmonary function, respectively. Results: No significant effects of lumbar flexibility were observed on trunk flexion test from the sitting position (P=.478) and standing position (P=.096) in the ABE than in the AHE. However, the length of ABE was longer significantly than it of AHE (P=.024). No significant effects of lung function were observed on the FVC (P=.410) and $FEV_1$ (P=.072) in the ABE group than in the AHE group. And also, no significant effects of chest circumference measurement were observed on the inspiration (P=.468) and expiration (P=.563) in middle chest circumference and inspiration (P=.104) and expiration (P=.346) in lower chest circumference. Conclusion: This study indicated that the ABE is only more effective in lumbar flexibility by lumbar length difference than AHE in healthy adults.

Deploy Position Determination for Accurate Parachute Landing of a UAV (무인기의 정밀 낙하산 착륙을 위한 전개지점 결정)

  • Kim, Inhan;Park, Sanghyuk;Park, Woosung;Ryoo, Chang-Kyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.6
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    • pp.465-472
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    • 2013
  • In this paper, we suggest how to determine the parachute deploy position for accurate landing of a UAV at a desired position. The 9-DOF dynamic modeling of UAV-parachute system is required to construct the proposed algorithm based on neural network nonlinear function approximation technique. The input and output data sets to train the neural network are obtained from simulation results using UAV-parachute 9-DOF model. The input data consist of the deploy position, UAV's velocity, and wind velocity. The output data consist of the cross range and down range of landing positions. So we predict the relative landing position from the current UAV position. The deploy position is then determined through distance compensations for the relative landing positions from the desired landing position. The deploy position is consistently calculated and updated.

Study on Evaluation Method of Flow Characteristics in Steady Flow Bench(5)-Effect of Evaluation Position (정상유동 장치에서 유동 특성 평가 방법에 대한 연구(5) - 평가위치의 영향)

  • Cho, Siehyung;Ohm, Inyong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.2
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    • pp.179-189
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    • 2017
  • This paper is the fifth investigation on the methods of evaluating flow characteristics in a steady flow bench. In previous studies, several assumptions used in the steady flow bench were examined and it was concluded that the assumption of the solid rotation may lead to serious problems. In addition, though the velocity profiles were improved as the measuring position went downstream, the distributions were far from ideal regardless of the valve angle and evaluation position. The eccentricities were also not sufficiently small to disregard the effect on impulse swirl meter (ISM) measurement. Therefore, the effect of these distribution and eccentricity changes according to the positions needs to be analyzed to discuss the method of flow characteristics estimation. In this context, the effects of evaluation position on the steady flow characteristics were studied. For this purpose, the swirl coefficient and swirl ratio were assessed and compared via measurement of the conventional ISM and calculation based on the velocity by particle image velocimetry(PIV) from 1.75B, 1.75 times bore position apart from the cylinder head, to the 6.00B position. The results show that the swirl coefficients by ISM strictly decrease and the curves as a function of the valve lift become smooth and linear as the measuring position goes downstream. However, the values through the calculation based on the PIV are higher at the farther position due to the approach of the tangential velocity profile to ideal. In addition, there exists an offset effect between the velocity distribution and eccentricity in the low valve lift range when the coefficients are estimated based on the swirl center. Finally, the curve of the swirl ratio by ISM and by PIV evaluation as a function the measuring position intersect around 5.00B plane except at $26^{\circ}$ valve angle.

An Electrohydraulic Position Servo Control Systems Using the Optimal Feedforward Integral Variable Structure Controller

  • Phakamach, Phongsak
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.936-941
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    • 2004
  • An Optimal Feedforward Integral Variable Structure or FIVSC approach for an electrohydraulic position servo control system is presented in this paper. The FIVSC algorithm combines feedforward strategy and integral in the conventional Variable Structure Control (VSC) and calculating the control function to guarantee the existence of a sliding mode. Furthermore, the chattering in the control signal is suppressed by replacing the sign function in the control function with a smoothing function. The simulation results illustrate that the purposed approach gives a significant improvement on the tracking performances when compared with some existing control methods, like the IVSC and MIVSC strategies. Simulation results illustrate that the purposed approach can achieve a zero steady state error for ramp input and has an optimal motion with respect to a quadratic performance index. Moreover, Its can achieve accurate servo tracking in the presence of plant parameter variation and external load disturbances.

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A Study of the Functional Anatomy of the Hand (손의 기능 해부에 대한 연구)

  • Park, Young-Han;Lee, Hyo-Jeong
    • Journal of Korean Physical Therapy Science
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    • v.13 no.1
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    • pp.61-74
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    • 2006
  • This study about functional anatomy of the hand. hand injuries are among the most common problems confronting patient, physical therapist and physicians. physical therapist should know about normal hand function and anatomical structure for hand injury, clinical reasoning and intervention. physical therapist should know about the Skeletal of the hand, Function of The Hand, Nerves of the hand, Sensation of the Hand, Intrinsic muscle, Power and Balance and Functional Position of the Hand. In this article, we discuss the physiologic properties of hand structure, biomechanical observation in hand function, sensation and nerves, hand positioning.

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