• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.137-139
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• 2003

In this paper, a design of VCM(Voice Coil Motor) for the measurement system of nano-level force and displacement was proposed and developed. This paper present the VCM shape for improvement of position resolution and guarantee of a large displacement. And then the finite element analysis method(FEM) utilized to produce linear driving thrust and satisfy required thrust of the system. The result shows the applicable possibility of the proposed VCM as a study for nano-level measurement system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.2
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• pp.200-206
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• 2006

An electric power efficiency of electrodeless fluorescent lamp depens on a big relative property of gas, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. in lamp. We used magnetic substance that opens self-examination material of electrodeless fluorescent lamp antenna. We used Mn-Zn type as the Ferrite. We have examined resistance, impedance and Q-factor's frequency characteristic by ferrite. Coil turns were changed from 13 to 15 turns to recognize brightness change of lamp by winding number. Optical equipment (LS-100) was used to measure brightness. We could know Q-factor's difference according to material is important part of antenna design. When an electrodeless fluorescent lamp was made using T company's PE22, it showed the highest brightness. As number of winding is increased the brightness increased, and starting characteristic became good.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.235-237
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• 2006

In this paper, the previous 2-D gradient coil design method using loop current elements is extended to 3-D or multi-layer structures which is useful for various MRI applications including MR microscopic imaging where relatively large space may be available for the implementation of the gradient coils. Either the power consumption or the stored energy (thus, inductance), or the combination of the two can be minimized with a set of chosen target field constraints. Complete 3-D design equations for the optimization as well as inductance or resistance calculation are derived. An effective coil shape correction method for a curved current pattern is also developed. The design method can also be easily extended to the active shielding structure.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.158-161
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• 2000

Generally superconducting generators(S. G.'s) will be classified into 2 types according to their field coil shape. The first one is race-trace type and the other is saddle type. Race-track type S.G.'s have almost the same structure with conventional salient pole generators which are being used as largely small scale machines with more than 4 poles. On the other hand saddle type S.G.'s correspond to conventional cylindrical generators with 2 poles used for large turbines in power plants. In this paper 1MVA S.G. with saddle type field coil is electromagnetically designed and based on the research results from development of 30kVA S.G. with race-track type field oils in our group. other parts such as cooling systems and power leads are presented.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.232-234
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• 1998

Race-track type superconducting coils are used for wiggler magnets of accelerators and field coils of superconducting generators(S.C.G) and so on. The shape is different from ordinary solenoidal type magnet, so the manufacturing situation and conditions become different and moreover according to these results the output characteristics of magnet also becomes different. In this paper we are dealing with race-track type coil design that is inserted into 30(kVA) S.C.G which will be manufactured before we make l(MVA) S.C.G plant. The design procedure is based on two dimensional electromagnetic analysis including laplace equations in cylindrical coordinate.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.140-151
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• 2000

Springs for vehicle suspension control the vibration of a car and influence on the ridability, safety, and life of a car. in the paper, the computer aided design program has been developed, which design the leaf spring shape from the given specifications using basic theory and the expert\`s knowledge, and the design results are checked by the analysis theory in order to increase the accuracy, and feed back to the design input. For the purpose of easy use, this program consists of pull-down menu and interactive input mode. To prove the effectiveness of this program, two springs, of which one is symmetric, other asymmetric, are designed and analyzed, and the outputs are compared to the experiments. Considering the tolerance of the given specifications, the results are good.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.50-54
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• 2007

In this paper, a dual-servo type VCM (Voice Coil Motor) for the measuring of nano-level displacement and small thrust is proposed and developed. The shape of VCM for improving the resolution of displacement and ensuring a large displacement are presented. The FEM (finite element method) is utilized to analyze the characteristics of VCM that produces linear driving thrust and satisfies the thrust that the measurement system requires. The Prototype is fabricated and an experiment is performed in order to measure displacement. As a result of simulation and testing, the proposed VCM shows the applicable possibility for a nano-level measurement system.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.117-124
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• 1993

This paper presents the study on the magnetic field analysis of magnetid deflection yoke using integral equation method. An integral equation method is developed for the computer modeling of the magnetic fields produced by color CRT and T.V. deflection yoke. Deflection of electron beams using magnetic fields is applied in a variety of display instruments such as te.evision receivers, electron probe instruments, etc. The magnetic field is solved by dividing these into the finite elements in the whole domain : the saddle coil which deflects the electron heam horizontally, the toroidal coil which deflects it vertically, magnetic core which enhances the magnetid fields genterated by the both coils. Using oblate spheroidal coordinates, this paper has had an easier access to the shape of magnetic deflection yoke chasing the boundaries than other coordinates.

• Progress in Superconductivity and Cryogenics
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• v.25 no.4
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• pp.40-44
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• 2023

For high-temperature superconducting power applications that need large current capacity, a large current conductor manufactured using multiple superconducting tape is required. Conductors being studied for large currents capacity such as CORC, TSTC, and RACC have advantages and disadvantages, and in order to use these conductors in coil form and apply them to AC power devices, research on magnetization loss occurring in superconductors due to external magnetic fields is essential. To accurately measure magnetization loss in a conductor that is twisted by stacking straight conductors like TSTC, the correlation between the measuring system and the shape of the sample must be clearly known to accurately measure the loss. In this paper, we will confirm the difference in magnetization loss measurement values according to the correlation between the length of the pickup coil and the twist pitch of the sample in CORC and TSTC shapes, and review considerations for accurate magnetization loss measurement from the results.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.257-264
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• 2000

In this study, optimization for press forming condition of low arm was performed with explicit dynamic FEM code, Pam-Stamp. FEM simulation was coupled with the Taguchi's experiment technique having three design variables - friction coefficient, plastic anisotropy parameter, and blank shape - which are chosen to be optimized. The simulation results were compared with those of experiment. We found out the change of blank shape among these three design variables is very effective in optimizing press forming condition of low arm. In addition, the modified blank shape shows high yield of slitting coil.