• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.39-43
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• 2002

In this thesis, a λ/4 hair-pin resonator is proposed to reduce the size of resonators. A LTCC MLC bandpass filter is designed using the λ/4 hair-pin resonators. The electromagnetic coupling structure between two planar resonators is analysed. The equivalent circuit is derived to explain the behavior of the LTCC MLC bandpass filter using λ/4 hair-pin resonators. A design procedure is also described. The simulated and measured results of 2-pole bandpass filter are presented.

• Journal of the Korean Institute of Navigation
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• v.19 no.2
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• pp.99-106
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• 1995

A wide band design method of an electromagnetic wave absorber with square ferrite cylinders in the second layer, which has very wide band frequency characteristics, is proposed and discussed. A theoretical model using the equivalent material constants method is also evaluated and proposed for its accuracy by comparison with Hashin-Shtrikman formulas. Based on the developed model, wide band electromagnetic wave absorbers with excellent reflective frequency characteristics in the frequency range of 30MHz to 3, 690MHz were designed.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.28-31
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• 1990

Electromagnetic levitation system became power-full because of Its high speed, safety, reliability, and so forth So, in this paper, various characteristics of magnet in electromagnetic levitation system were analyzed by Finite Element Method and its design parameters were proposed by simulation results.

• Journal of the Korean Institute of Navigation
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• v.18 no.2
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• pp.151-158
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• 1994

A wide band design method of an electromagnetic wave absorber using exponentially tapered ferrite, which has very wide band frequency characteristics, is proposed and discussed. The wide band electroma-gnetic wave absorber can be designed by the proposed equivalent material constants method for the re-gions varying spatially in the shape of ferrite. Futhermore, the wide band ferrite electromagnetic wave absorber with taper, which have not only exce-llent reflectivity frequency characteristics but also the band width of 30MHz to 2150 or 2450MHz under the tolerance limits of -20dB reflectivity, were designed.

• Fashion & Textile Research Journal
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• v.10 no.3
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• pp.385-388
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• 2008

Four kinds of PET fabrics were coated with Copper and Nickel by electroless chemical plating, and the electromagnetic wave shielding effectiveness for those samples have been examined. The shielding effectiveness showed between 90 dB and 70 dB, and it related to the fabric structure, such as cover factor and cloth density. The dense fabric structure showed the better shielding effect.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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• pp.366-373
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• 2012

In this paper, serious changes in the electromagnetic environment with increasing power and energy capabilities for electric driving and military mission are discussed. Design and control strategies on the Electro-Magnetic Compatibility(EMC) for the series hybrid electric vehicle are proposed to minimize the effects of electromagnetic interferences.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.849-852
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• 2006

In this research electromagnetic waves in interception and that do so that keep in step in trend that develop material that draw water by sucking and material that can absorb electromagnetic waves use and do goods anger focus. Character that electromagnetic waves use and make material that can absorb electromagnetic waves to be happened much in portable phone for instance using sticking on hand phone bar Terry part electromagnetic waves intercept wish to. Wish to study character that can conglutinate by evil worldly affairs reason combined us introducing character concept beside function originally electromagnetic waves interception and use region that intercept this time. Because character application process executes question investigation, design preference degree reflects the highest thing and arranged to conclusion.

• Journal of electromagnetic engineering and science
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• v.1 no.1
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• pp.95-99
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• 2001

According to the progress of the electronic industy and radio communication technologies, mankind might enjoy its abundant life On the other hand, many social problems such as EMI, and unnecessary electromagnetic wave occur due to the increased use of electromagnetic wave. Therefore, the organiztions such as CISPR, FCC, ANSl,etc. have provided the standard of electromagnetic wave enviroment for the countermeasure of the EMC. It had been required that the absorbing ability of an electromagnetic wave absorber is more than 20 dB, the bandwidth of which is required through 30 MHz to 1,000 MHz for satisfying the international standard about an anechoic chamber for EMI/EMS measurment. From November of 1998, however, the CISPRll has accepted the extended frequency band from 1 GHz to 18 GHz additionally in the bandwidth of EMI measurementent$^{[1]}$ . In this paper, we proposed a new type absorber satisfying the above requirements and carried out broadband design using the equivalent material constants method. Futheremore, the experiments were carried out over the frequency band from 30 MHz to 2 GHz, and hence, the validity of the proposed design theory was confirmed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1045-1051
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• 2016

This paper introduces a new optimal design method using a bacterial survival strategies for a ectromagnet of Maglev transportation vehicle. Usually, an electromagnetic suspension which has more advantages than electro dynamic suspension is used in Maglev systems. However, the structural constraints must be considered in the optimal design of an electromagnet for electromagnetic suspend system. In this paper, the optimal design method of a electromagnet based on a bacterial survival strategies optimization algorithm to design the electromagnet satisfying the structural constraints. The effectiveness of the proposed method was verified by Matlab simulations and the simulation results show that the proposed method is more efficient than conventional methods.

• Journal of Magnetics
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• v.20 no.2
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• pp.193-200
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• 2015

Direct-acting solenoid valves are used in the automotive industry due to their simple structure and quick response in controlling the flow of fluid. We performed an optimization study of response time in order to improve the dynamic performance of a direct-acting solenoid valve. For the optimal design process, we used the commercial optimization software PIAnO, which provides various tools for efficient optimization including design of experiments (DOE), approximation techniques, and a design optimization algorithm. 35 sampling points of computational experiments are performed to find the optimum values of the design variables. In all cases, ANSYS Maxwell electromagnetic analysis software was used to model the electromagnetic dynamics. An approximate model generated from the electromagnetic analysis was estimated and used for the optimization. The best optimization model was selected using the verified approximation model called the Kriging model, and an optimization algorithm called the progressive quadratic response surface method (PQRSM).