• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.42-49
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• 2005

Our purpose is to develop a precision magnetic displacement sensor that has sub-micron resolution and small size probe. To achieve this, we first have tried to establish mathematical models of a magnetic sensor in this paper. The inductance model that presents basic measuring principle of a magnetic sensor is based on equivalent magnetic circuit method. Especially we have concentrated on modeling of magnetic flux leakage and magnetic flux fringing. The induced model is verified by experimental results. The model, including the magnetic flux leakage and flux fringing effects, is in good agreement with the experimental data. Subsequently, based on the augmented model, we will design magnetic sensor probe in order to obtain high performances and to scale down the probe.

• Membrane Journal
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• v.13 no.4
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• pp.239-245
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• 2003

The origin of large difference of selectivity of $C_3H_6$ over $C_3H_8$ between pure gas and mixed gas through silver polymer electrolyte membranes is investigated. Firstly, the effect of feed condition on the permeance of mixture gas ($C_3H_6/C_3H^8$) and the separation performance is examined. Upon decrease of the $C_3\;H_6$ concentration, the $C_3H_6$ permeance decreased whereas the permeance of $C_3H_8$ increased, resulting in the decrease of the selectivity of $C_3H_6/C_3H_8/.$ This result is ascribed to the $C_3H_6$-induced plasticization of membranes. Experimental results were validated by means of mathematical modeling, where pressure independent permeabilities were used.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.34-36
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• 1989

Since the linear step motor(LSM) has the merits which can be controlled the position and velocity by using the micro-computer and has no mechanical transducer such as belt and gear, it's usefullness has been fitted for the printer, x-y plotter, OA machinery and so on. In designing the LSM, we are faced up to the calculation of forces. in this paper, the permeance modeling method suited for the design of transverse flux type linear step motor(TFM) is presented and simulated.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.4
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• pp.28-33
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• 2006

Various precision engineering studies have attempted to remove mechanical friction, which causes the performance of a system to deteriorate, from precision positioning devices. Since the classical fluid lubrication method has some disadvantages in clean environments, attention has been focused on magnetic bearings and contact-free systems with their pollution-free characteristics. In this paper, f electromagnets are modeled and analyzed, not only for magnetic bearings but also for contact-free electromagnetic actuators. Three types of electromagnets that are appropriate for various applications were considered using magnetic circuitry theory. The results were experimentally validated.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.125-132
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• 1993

On this study, magnetic force versus input currents is analyzed by modeling taper plunger type proportional electromagnet of ISC valve using the permernce method. And, the reliabiliy of simulation is verified by comparing the experimental values with the calaulate magnetic force. From the result of this study, it is found that the taper angles at plunger and core, the length of air gap between plunger and yoke are the prumary factors in designing taper plunget type proportional electromagnet. Magnetic force is decreased as a whole according to increasing the air gap between pluger and yoke, and vise versa. But, the magnetic force is not proportional to current, when the air gap is very small. In case of decreasing the taper angle of pluger, the stroke range of plunger where magnetic force is proportional to current becomes farther from core.