• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.98-106
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• 2007

This paper represent improved on-line turn off angle control schemes for switched reluctance motors based on current control. For the purpose of finding the optimal commutation switching angle point with improved controller, it is utilized turn on and turn off position calculation with inductance vs. current vs. not linkage analysis method. The goal of proposed paper is the maximization of the energy conversion per stroke and torque ripple reduction and obtaining approximately flat-topped current waveform. The proposed control scheme is demonstrated simulation and on a prototype experimental system.

• Transactions of Materials Processing
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• v.25 no.1
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• pp.29-35
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• 2016

In the current study, finite element analysis was conducted for the press hemming of automotive panels in order to predict various hemming defects such as roll-in and turn down. The analysis used the exact punch movement based on the cam location and considered the sealer between the inner and outer panels with an artificial contact thickness. The analysis results quantify the hemming defects especially at the flange edge in the matching region of the head lamp. A design of experiments along with the parameter study was used to obtain the optimum process parameters for minimizing hemming defects. The optimization process selects the intake angle, bending angle of the hemming punch, and the flange height of the outer panel. The optimum design process determines an appropriate tool angle and flange height to reduce the roll-in and turn-down as compared to the initial design.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1061-1062
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• 2006

This paper represent improved On-line Turn off, commutation Angle control schemes for switched reluctance motors based on current control. For the purpose of the finding optimal commutation switching angle point, it is utilized turn on and turn off position calculation with inductance vs. current vs. flux linkage analysis method. The goal of proposed paper is the maximization of the energy conversion per stroke and maximizing efficiency and obtaining approximately flat-topped current waveform. The proposed control scheme is demonstrated on a simulation experimental result.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.555-557
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• 2006

This paper represent improved On-line Turn off Angle control schemes for switched reluctance motors based on current control. For the purpose of the finding optimal commutation switching angle point, it is utilized him on and turn off position calculation with inductance vs. current vs. flux linkage analysis method. The goal of proposed paper is the maximization of the energy conversion per stroke and maximizing efficiency and obtaining approximately flat-topped current waveform. The proposed control scheme is demonstrated on a prototype experimental system.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.231-234
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• 2001

The torque of SRM depends on phase current and the derivative of inductance. But the inductance of SRM is nonlinearly changed according to rotor position angle and phase current because of saturation in magnetic circuit. Therefore this has a concern in torque ripple and speed variation, and it is difficult to control the desired torque The torque of SRM depends on phase current and the derivative of inductance. But the inductance of SRM is nonlinearly changed according to rotor position angle and phase current because of saturation in magnetic circuit, and it is difficult to control the desired torque. This paper proposes an optimization control scheme by adjusting both the turn-on and turn-off angle according to high efficiency points which are simulated by GA-Neural Network, which is used to simulate the reasonable switching angle which is nonlinearly varied with rotor speed and load.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.551-559
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• 2015

This paper's focus is in reducing the torque ripple and increasing the average torque by optimizing switching angles of 8/6 switched reluctance motor while implementing a robust speed controller in the outer loop. The mathematical model of the machine is developed and it is simulated using MATLAB/Simulink. An objective function and constraints are formulated and Optimum turn-on and turn-off angles are determined using Particle swarm optimization and Genetic Algorithm techniques. The novelty of this paper lies in implementing sliding mode speed controller with optimized angles. The results from both the optimization techniques are then compared with initial angles with one of them clearly being the better option. Speed response is compared with PID controller.

• Advances in Automotive Engineering
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• v.1 no.1
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• pp.1-20
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• 2018

The aim of this study is the optimization of the parameters of interconnected Hydro-Pneumatic (HP) suspension system of a three-axle vehicle for ride comfort and handling. For HP suspension systems of equivalent vertical stiffness and damping characteristics, interconnected HP suspension systems increase roll and pitch stiffness and damping characteristics of the vehicle as compared to unconnected HP suspension systems. Thus, they result in improved handling and braking/acceleration performances of the vehicle. However, increased roll and pitch stiffness and damping characteristics also increase roll and pitch accelerations, which in turn result in degraded ride comfort performance. Therefore, in order to improve both ride comfort and vehicle handling performances simultaneously, an optimum parameter set of an interconnected HP suspension system is obtained through an optimization procedure. The objective function is formed as the sum of the weighted vertical accelerations according to ISO 2631. The roll angle, one of the important measures of vehicle handling and driving safety, is imposed as a constraint in the optimization study. Upper and lower parameter bounds are used in the optimization in order to get a physically realizable parameter set. Optimization procedure is implemented for a three-axle vehicle with unconnected and interconnected suspension systems separately. Optimization results show that interconnected HP suspension system results in improvements in both ride comfort and vehicle handling performance, as compared to the unconnected suspension system. As a result, interconnected HP suspension systems present a solution to the conflict between ride comfort and vehicle handling which is present in unconnected suspension systems.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.530-535
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• 2006

The Pusan clays are soft and thick deposits and in some places, they reach even up to 50-70m. So, the pile foundations are inevitable in almost all cases. But they are significantly expansive when the length of the pile reaches about 70m. In this study, a comprehensive parametric study has been carried out in order to reduce the pile length and number of piles required in turn the cost of the foundation for particular building. A belled shaft pile has been optimized for a typical soil profile using the PLAXIS (FEM code). These results have shown a new direction of the pile foundation in Pusan, Korea. The results including the variation of contact pressures at the bottom of the bell, optimization of the angle of the bell and height of the bell in terms of the diameter of the shaft. And also, the design curves have been generated so that they can be directly used for design of belled shaft foundations. However, the structural strength criterion is being checked in the concerned laboratory.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.608-610
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• 2001

In this paper, 6/4 Switched Reluctance Motor(SRM) which has simple structure and little switching element is selected basic analysis model. In order to reduce torque ripple causing noise and vibration, we execute optimization of geometric parameters (stator and rotor pole arc) and electrical parameters (turn-on angle and turn-of angle) by means of combining Fletcher-Reeves's Conjugate Directions and Finite Element Method (FEM) considering driving circuits. When considering the switching condition according to inductance profile, torque characteristics is influenced by geometric and electrical parameters importantly. The pole arc and switching angle of the optimum can also obtain the low torque ripple without high currents.

• Journal of Drive and Control
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• v.20 no.4
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• pp.9-16
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• 2023

This paper analyzed a drainage tower used to drain water in flooded areas. Multi-body dynamics simulation was used to analyze the dynamic behavior of the drainage tower. Structural analysis, flexible-body dynamic analysis, and rigid body dynamic analysis were done to study the maximum Von-Mises stress of the drainage tower. The results showed that the maximum Von-Mises stress occurs at the turn table, and it decreases when the angle of the boom is increased. Also, the rate of the change of angle affects the maximum stress so that the maximum stress changes more when the angular velocity of the boom increases. Based on the rigid body dynamic analysis and the theoretical analysis results, the centrifugal force from the angular velocity makes the difference in the maximum stress at the turn table because of the difference in their direction. Consequently, it was concluded that the centrifugal force should be considered when designing construction machinerythat can rotate.