• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1879-1880
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• 2006

In electric motor coaches, when the adhesion force between rail and driving wheel decreases suddenly, the electric motor coach has slip phenomena. The characteristics of adhesion force coefficient is strongly affected by the conditions between rails and driving wheels, such as moisture, dust, and oil on the rails and so on. This paper proposes the simulation system for slip & slide test using virtual train. We can easily research the adhesion characteristics and adhesion control method with this equipment under the sudden variation of the adhesion force coefficient.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.1020-1022
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• 1998

Silicon membrane to be used for micropump is fabricated and the deflection of the membrane driven by the electromagnetic force is measured. Silicon and glass are anodic bonded and Si is thinned. Silicon membrane is fabricated by the glass etching. The gold pattern can be protected against HF by the washing and fixing process under the glass etching process. The electromagnetic force is gained by the magnetic field driven by the current flowing through two coils. Deflection of the silicon membrane has a tendency of increasing with the increase of the driving current.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.22-32
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• 2001

One of the important considerations in designing a machine tool is the durability. In this study, a durability estimation system for horizontal machining centers is developed to evaluate the effects of structural specification and driving condi-tions on the durability. All loads such as weights, inertial forces, cutting force and so on, are automatically transferred from the upper elements to the lower elements by the force flows which can be derived from the structural code of horizontal machining centers. And the external loads applied to the motion elements such as bearings, LM guides, ball screws and ao on, are determined by the equilibrium conditions of force and moment. Especially, the durability of horizontal machining centers is estimated based on the lifes of motion elements operating under the desired driving conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.848-853
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• 2001

Electrostatic actuation was adopted for ease of fabrication. We proposed a new driving scheme that uses the vector sum of force generated by comb-finger and by parallel plate. The moving and fixed electrodes are arranged to maximize the driving force. In this paper, an electrostatic field analysis is performed by Maxwell analysis tool for micro actuators. From the analysis, a comb-parallel type micro-actuator with 4${\mu}{\textrm}{m}$ width, 6${\mu}{\textrm}{m}$ overlap and 45${\mu}{\textrm}{m}$ height could be designed. In order to compare the new type of actuator with the conventional comb type of actuator, we arranged that both types have the same area and the same number of actuators. To make a high aspect ratio structure, we are developing fabrication process using SU-8 and electro-plating.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.3-10
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• 1999

One of the important considerations in designing a machine tool is the durability. In this study, a durability estimation systems for horizontal machining centers is developed to evaluate the effects of structural specification and driving conditions on the durability. All loads such as weights, inertia forces, cutting force and so on, are automatically transferred from the upper elements to the lower elements by the force flows which can be derived from the structural code of horizontal machining centers. And the external loads applied to the motion elements such as bearings, LM guides, ball screws and so on, are determined by the equilibrium conditions of force and moment. Especially, the durability of horizontal machining center is estimated based on the lifes of motion elements operating under the desired driving conditions.

• The Journal of the Acoustical Society of Korea
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• v.2 no.1
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• pp.48-58
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• 1983

The transient sound radiation from the impact between a steel ball and a thick plate is analyzed theoretically and compared with experiment results. The derivation process itself is difficult to analyze sound radiation characteristics theoretically for a thick plate with some resonances but may be investigated from measured data. During mechanical impacts, arbitrary driving point importance for an elastic system enables to predict by using mechanical importance method. In order to obtain approximate solution for an impact model testing, the surface Helmholtz integral formulation based on the integral expression for pressure in the field in terms of surface pressure and normal velocity is used as a basis. A simple expression is developed for an impulsive response function, which is time dependent velocity potential and pressure for an impact may then be computed by a convolution of exciting force. In estimating of elastic-acoustical correlation problems, mechanical inertance, overall transfer function and radiation resistance obtained by signal processing techniques are used. The usefulness is confirmed by applying these methods prediction of arbitray driving pint inertance, radiated sound pressure and exciting force.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.909-910
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• 2007

To design the Molded Case Circuit Breaker(MCCB) requires electromagnetic analysis in contact system when the circuit breakers interrupt fault currents. This paper has made sure that there are two ways increasing arc driving force, one is a change of contact point and the other way inserts additionally the magnetic plate. Finally, we have carried out the analysis of eddy current to identify a decrease of arc driving force because of fault currents. In this paper, MCCB models have been analyzed base on 3D-FEM by Maxwell program.

• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.132-144
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• 2004

This paper presents a new method driving multiple robots to their goal position without collision. To consider the movement of the robots in a work area, we adopt the concept of avoidability measure. The avoidability measure figures the degree of how easily a robot can avoid other robots considering the velocity of the robots. To implement the concept to avoid collision among multiple robots, relative distance between the robots is proposed. The relative distance is a virtual distance between robots indicating the threat of collision between the robots. Based on the relative distance, the method calculates repulsive force against a robot from the other robots. Also, attractive force toward the goal position is calculated in terms of the relative distance. These repulsive force and attractive force are added to form the driving force for robot motion. The proposed method is simulated for several cases. The results show that the proposed method steers robots to open space anticipating the approach of other robots. In contrast, since the usual potential field method initiates avoidance motion later than the proposed method, it sometimes fails preventing collision or causes hasty motion to avoid other robots. The proposed method works as a local collision-free motion coordination method in conjunction with higher level of task planning and path planning method for multiple robots to do a collaborative job.

• Journal of Power System Engineering
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• v.16 no.1
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• pp.91-97
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• 2012

It is being accelerated to develop environment-friendly vehicles to solve problems on the energy and environment of earth. The electric driving motor commonly installed in these vehicles has the excellent control capability such as fast response and accurate generation to torque control command. Especially, in-wheel motor has the additional merit such as independently driving each wheel in vehicle. Recently, being developed various control algorithm to enhance the safety and stability of vehicle motion using actively the merits of in-wheel motor. In addition to that, being issued the possibility of enhancing the ride comfort and attitude of vehicle motion such as pitching and rolling. In this paper, investigate the theoretical relationship between the braking/driving force and the motion of sprung mass of vehicle and propose the control method to enhance the ride comfort and attitude of vehicle motion. The proposed control method is proved through the simulation with vehicle model provided by TruckSim software which is commercial one and specializes in vehicle dynamics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1296-1301
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• 2012

This paper deals with development of the driving-will control system in power-assisted electric wheelchair. Nowadays, population of elderly people has been increased rapidly, and also an electric wheelchair has been considered as the device for the elderly. Especially, power-assisted electric wheelchair can overcome problems that a conventional electric wheelchair holds, such as lack of movement of wheelchair user. In this paper, we propose the sensors system to measure the driving-will force and perform the control action for a power-assisted electric wheelchair. And motion performance of the proposed system is verified through the experiment.