• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.3
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• pp.227-237
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• 2007

Various methods and torque generating devices are developed and employed to apply proper torque clinically. In this study, clinically used torque control devices are measured whether uniformed and precise torque are generated. Digital torque gauge are employed for measurement and torque driver, torque limiting device, torque indicating device are used for torque generating devices. ${\chi}^2$ distribution was formed and One-way ANOVA(Turkey test) was performed to measure torque values generated by each torque generating device. In the results, all companies have been shown slight errors and deviations. This indicates a difficulty of applying precise torque. Therefore, it would be recommended torque generating device should be checked whether uniformed and precise torque can be generated and an error should be corrected.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.252-260
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• 1997

In this paper, a friction compensation method using a disturbance observer is proposed for an impedance control of pneumatic manipulator. It is assumed that the generated torque by a pneumatic actuator can be estimated based on the pressure signals and the discharge volume. In order to improve the dynamic characteristics of the pneumatic actuator driven by meter out method, we construct the inner torque control system by feeding back the generated torque. In order to reduce the influence of disturbances comprising friction torque and parameter variations of plant, the impedance control system is constructed with a disturbance observer which estimates the disturbances based on the generated torque of pneumatic actuator, the angular velocity and the reaction torque. From some experiments, it is confirmed that the proposed control system is effective to improve the robustness for the friction torque in the impedance control of a pneumatic manipulator.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.105-113
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• 2006

The purpose of this study was to analyze the joint torque of triple segmental system in golf driver swing. For this purpose, joint torque were calculated. In order to determine the load on the lumbar region, a triple segmental system was set for wrist, left shoulder and lumbar, torque working on the lumbar region were estimated. For this study, a total of 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint torque was generated in the direction opposite the target on wrist and shoulder during down swing, while in the direction towards the target on the lumbar region. During impact and release, the torque on the wrist joint was converted from the direction opposite the target to the direction towards the target, while the torque on the lumbar region was generated vice versa. The joints on the club-arm-shoulder were generated in the opposite direction at the beginning of down swing when the torque on the thorax-pelvis began to be generated, and then, the torque on the thorax-pelvis began to lower, while that on the club-arm-shoulder began to increase. Thus, a rapid decrease of the torque on the lumbar region linked to the low trunk acted to increase moment and joint torque on the arm-club region.

• 전기의세계
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• v.21 no.2
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• pp.5-8
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• 1972

The purpose of this paper is, as a preliminary step to study on the method of analysing the torque of toothed solid iron rotor, to make an inquiry into the torque calculation formula of homogenious solid iron rotor without slot. The starting point for its theoretical analysis on torque generated by eddy current in solid iron rotor is based on the maximum air gap flux density. In solid rotor induction motor, torque generated by rotor core is considerably large in the range of large slip. The calculated value and observed value on the test machine are also examined in this paper.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1087-1090
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• 2007

A wireless magnetic torque sensor is utilized to measure the torque generated in the rotating shaft in magnetic field without connecting to the shaft by any wire. In this study, a new wireless magnetic torque sensor was introduced. The structure of the sensor was explained detailed as well as its operation principle. Resulting from the torque measurement experiment results, the sensor was proven to measure the generated torque effectively. Compared with traditional contact torque sensor, the wireless one has low cost and good environment adaptation ability. Moreover, the intractable wrapping wires around the shaft are removed in this design. Hence the wireless torque sensor may be expected as a possible sensing device for many applications, such as the electric assisting rotation system in automobiles, the torque sensing system in motors, the arm rotation system in robotics and so on.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.540-552
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• 1996

In this paper, a compensation method of disturbance using a disturbance observer is proposed for a force control of a pneumatic robot manipulator. The generated torque by a pneumatic actuator can be estimated based on the pressure signals. The inner torque control system is constructed by feeding back the generated torque to improve the dynamic characteristics of the actuator. In order to reduce the influence of disturbances comprising friction torque, parameter variations of plant and environment and so on, the reaction torque control system is constructed with a disturbance observer which estimates the disturbances based on the reference input to the inner torque control system and the reaction torque sensed with a forced sensor. From some simulations and experiments, it is confirmed that the proposed control system is effective to improve the robustness for the friction torque and the parameter change of object in the force control of a pneumatic robot manupulator.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.212-213
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• 2013

This paper proposes the algorithm of torque distribution in the electric wheel-chair using 2D joystick for drive safety. For the accurate driving performance, the specific and precise torque distribution is required in both wheels depending on signals of X-Y axis that is generated from 2D joystick. The signals of X-Y axis from joystick are transformed into the propulsion force and the torque reference. And the torque reference can be generated through the dynamic model of wheel-chair. The optimal dynamic characteristics of the electric powered wheelchair can be obtained, by adjusting the sensitivity coefficients of propulsion force and torque reference, In addition, the system takes smooth and stable control characteristics due to continuous torque output at all directions of joystick. The several simulations verify the usefulness of the proposed algorithm about torque distribution.

• Restorative Dentistry and Endodontics
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• v.48 no.1
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• pp.10.1-10.9
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• 2023

Objectives: This study compared the buckling resistance of 3 nickel-titanium (NiTi) retreatment file systems and the torque/force generated during retreatment. Materials and Methods: The buckling resistance was compared among the D-RaCe (DR2), HyFlex Remover, and Mtwo R25/05 retreatment systems. J-shaped canals within resin blocks were prepared with ProTaper NEXT X3 and obturated by the single-cone technique with AH Plus. After 4 weeks, 4 mm of gutta-percha in the coronal aspect was removed with Gates-Glidden drills. Retreatment was then performed using DR1 (size 30, 10% taper) followed by DR2 (size 25, 4% taper), HyFlex Remover (size 30, 7% taper), or Mtrwo R25/05 (size 25, 5% taper) (15 specimens in each group). Further apical preparation was performed with WaveOne Gold Primary. The clockwise torque and upward force generated during retreatment were recorded. After retreatment, resin blocks were examined using stereomicroscopy, and the percentage of residual filling material in the canal area was calculated. Data were analyzed using 1-way analysis of variance with the Tukey test. Results: The HyFlex Remover files exhibited the greatest buckling resistance (p < 0.05), followed by the Mtwo R25/05. The HyFlex Remover and Mtwo R25/05 files generated the highest maximum clockwise torque and upward force, respectively (p < 0.05). The DR1 and DR2 files generated the least upward force and torque (p < 0.05). The percentage of residual filling material after retreatment was not significantly different between file systems (p > 0.05). Conclusions: NiTi retreatment instruments with higher buckling resistance generated greater clockwise torque and upward force.

• Journal of Magnetics
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• v.17 no.3
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• pp.200-205
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• 2012

Recently, applications of the reluctance torque motor have been quite limited due to their inherent limitation of noise and vibration and thus, researches on the reluctance motor have been limited as well. However, with the tremendous increase in the cost of rare earth material magnets, studies of the reluctance torque motor are being conducted more and more. In principle, reluctance torque is generated when the inductance is changed. Therefore, in order to generate continuous torque in the switched reluctance motor, it is necessary to figure out the exact inductance level corresponding to the rotor position and the current level to be applied in that rotor position, respectively. If the current level or the rotor position is not accurately determined, then the generated reluctance torque becomes unstable and undesirable torque ripples prevail to eventually cause noise and vibrations. In this research, a flux switched reluctance motor (FSRM), which is classified into the switched reluctance motor (SRM), was studied. A methodology using the current shaping control according to the rotor position was proposed. Based on the proposed methodology, the optimal current waveform and the torque distribution function for the FSRM to minimize torque ripple was established and demonstrated in this paper.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.6
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• pp.414-419
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• 2015

Recently, commercial ships and other specialized vessels with electric propulsion system employ variable speed induction motor as its prime mover. The wide application of electrical motors also includes being the main drive system in most industrial machineries. However, during its start-up, shutdown, and brake switch operation, excessive torque variation are generated. As such, flexible coupling are installed in order to reduce the transmitted torque fluctuation to the driven side. In this paper, the pulse torque generated by an variable speed induction motor was analyzed theoretically and through measurement of torsional vibration. Induction motor with inverter on marine propulsion system and industrial compressor were used as experimental subjects. The study confirmed that pulse torque are generated regardless of motor speed and interpreted as a vibration source of the whole system. Results presented herein can be adopted as the basis in future amendment of inspection classifying body regulations.