• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.2
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• pp.69-75
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• 2004

In this paper, we propose the shape of extremely small thrust VCM for application of the Nanoindenter, which enables control of very small force and displacement. We performed optimization of the VCM shape using conjugated gradient method. And the purposes of optimization are the minimization of the permanent magnet size for the efficient systems, minimization of deviation of flux density from the air gap for operate on regular thrust and a linearization of thrust for a good control characteristic. The finite element method is used for characteristic analysis. The node moving method is used to redundant changes of design variables. As a result, the VCM produces a yew small force by the difference of flux density of lower part from higher one. Also, in a wide range of current (0［A］-1［A］), the VCM produces linear driving thrust by saturating the magnetic circuit path and operate on regular thrust by minimizing deviation of flux density of the air gap.

• Transactions on Electrical and Electronic Materials
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• v.13 no.3
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• pp.125-128
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• 2012

This paper describes the design, simulation and characterization of an AA size electromagnetic energy harvester that is capable of converting environmental vibration into electrical energy. A magnetic spring technique is used to scavenge energy from low frequency external vibrations. The generator is characterized by ANSYS 2D finite element analysis, and optimized in terms of moving mass, fixed magnet size, coil width and load resistance. The optimized energy harvester is able to generate 53.5 mW of average power at 8.1 Hz resonance frequency, with a displacement of 0.5 mm.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.483-486
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• 2001

This Paper the state-of-the art indirect induction heated boiler and induction heated hot air producer using the voltage-fed series resonant high-frequency inverter whice can operate in the frequency range from 20kHz to 50kHz. A specially-designed induction heater composed of laminated stainless assembly with many tiny holes and interconnected spot welding points between stainless plates is inserted into the ceramic type vessel with external working coil connected to the inverter and tubelence fluid through this induction heater in moving fluid generates in the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from a practical point of view.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.965-967
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• 1993

In this paper, Take two perment magnets and three iron bars and wind copper wire around one or the bars. This paper demonstrate that the method or calculation yields the right results with MAXWELL-2D program package for computing magnetic field, also indicate the value to which the current in the coil has to be limited to prevent saturation of the iron or the cores. The Finally procedures for design of LDM are discussed.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.86-88
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• 1994

In this paper, we present the design procedure and analysis the fundamental characteristics for Linear DC motor using permeance method and finite element method. Designed LDM is made of two permanent magnets, three iron core and amateur windings. For the design the LDM, first of all it is nessary to calculate the air gap flux density and thrust force, after that to determine core size, the numbers of winding turns, winding width, motor cross section area and losses in the coil. Also, we analysis the fundamental characteristics for implemented LDM according to proposed design procedure, and we find that the implemented LDM generated constant thrust force for costant current as long as iron of core is not saturated. Finally, we find that the proposed design procedure in this paper is effective to design and implementation of LDM.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.135-137
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• 2005

In servo system demanding precision dynamic characteristics, application of the Permanent Magnet Linear Synchronous Machines (PMLSM) has advantage of analysis convenience by simple geometry and thrust ripple reduction from the sinusoidal back electromotive force and excited stator. Therefore, this paper presents design of surface-mounted PMLSM with slotless iron cored stator according to coil turns to satisfy the rate thrust. Also, from dynamic analysis for servo application of manufactured motor with heavy mass, we offer accurate range of the DC link voltage and acceleration in rate speed. This is applied to speed reference profile considering system characteristics in total length of moving position.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.65-69
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• 1989

Mather type dense plasma focus device was develooped for the feasibili쇼 study in its application to the x-ray lithography. To etermine the electrical characteristics,the temporal begavior of the discharge current and the voltage was measured by using the Rogowski coil and the high voltage probe respectively. The results are 9 $\mu\textrm{s}$ of the period, 18m$\Omega$ of resistance and 0.16$\mu$Η of inductance. The average current sheath velocity was measured by the light signal emitted at the moving plasma sheath. The light signal was detected through two fiber bundles. When the applied voltage was 13 kV and the initial jpressure of argon was 21.8 Pa, the best plasma focus was occurred. The x-ray emission characteristics from the plasma focus was determined by the x-ray pictures taken by pinhole camera. It is focus that the plasma was focused at 1.4 cm distant position above the center electrode and its diameter was about 1.0 m.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.98.1-98
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• 2001

An actuator using a permanent magnet and solenoid is proposed and designed in this paper. Its design concept is composed of a driving force generation, a guide mechanism, and a symmetric structure. At first, Driving Force generation uses a concept that is a change efflux by using a permanent magnet and solenoid. A permanent flux is generated by a permanent magnet. Changeable flux is created by a variable current flowing through coil such the solenoid. The direction of this flux is changed due to current flowing through coils. The combination of permanent and changeable fluxes make various flux densities between yokes of moving part and fixed yokes. And then, the flux densities create forces(F), which are used to drive this actuator, in lower and upper gap. In this actuator ...

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.4
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• pp.429-434
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• 2011

Bulk cargo loaded into ship can be damaged by various kinds reasons. This paper aims to analyze about cargo damage of coil carrier ship due to condensation. Condensation is the formation of liquid drops of water from water vapor. Condensation consists of small drops of water which form when warm water vapour or steam touches a cold surface such as a window. In general, condensation have occurred by temperature difference at large building and ship's tank. It is phenomenon that can occur often to oceangoing vessel moving temperature difference places in similar time. This paper proposes a new method using dehumidification device and fan heater to prevent bulk cargo damage of coil carrier ship from condensation.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.4
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• pp.356-363
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• 2003

An eddy current testing system was developed for detection of flaws in the ferromagnetic steel tubes. Because the eddy current signals from the ferromagnetic steel tubes could be distorted easily due to an irregularity of magnetic permeability, magnetic saturation is required to suppress this variation of magnetic fields. A magnetic saturation probe with the Hemholtz coil was designed for the inspection of the steel tubes. The bandwidth pass filters were adapted to minimize the noise from the DC magnetization. When using the designed test probe, the flaw signals could be discriminated from the noise. The system was tested at the production line and showed a capability of detecting flaws, like a drilled hole of the diameter of 2.0mm at the moving speed of 1m/sec.