• Proceedings of the Korean Magnestics Society Conference
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• 1995.05a
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• pp.14-15
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• 1995

• Proceedings of the Korean Magnestics Society Conference
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• 1995.05a
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• pp.58-59
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• 1995

• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.1-1
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• 2005

• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.2-2
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• 2005

• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.4-4
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• 2005

• Proceedings of the Korean Magnestics Society Conference
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• 2007.12a
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• pp.151-151
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• 2007

• KEPCO Journal on Electric Power and Energy
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• v.4 no.1
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• pp.9-12
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• 2018

The use of underground transmission power lines is expanding for the beauty and convenience of the near city. However, there is a lack of research on the losses from underground transmission power lines, especially those that support three-phase cables operating 24 hours a day. Since the supporting the cable is made of a material having a conductivity and a magnetic permeability, an eddy current and a hysteresis loss are generated due to a magnetic field caused by a current flowing in the cable. Losses occurring in this case adversely affect the power energy transfer efficiency, so research on loss is necessary. Therefore, in this paper, we analyzed the eddy currents and hysteresis losses that occur in a supporting a cable through three - dimensional finite element analysis.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.5
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• pp.574-583
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• 2006

Statement of problem : The use of permanent magnetics is increasing in implant dentistry. Purpose : This study is to know the effect of permanent magnetics on bone matrix formation of osteoblasts. Materials and methods : The konus abutment-shaped permanent magnetics were connected to the implant fixture, and placed on the culture plate. The osteoblast-like cell Mc3T3E1 were used for cell culture. As the control group, the implants were connected to titanium healing caps, and cultured in the same conditions of experimental group. After 3. 7, 14 days, cells were cultured, and we measured and compared the amount of collagen type I, osteocalcin, which is bone matrix protein by Western immunoblotting analysis. Results: As a result of Western immunoblotting analysis for estimating the amount of bone extracellular matrix, there was no difference between osteoblast of the experimental group and the control group during 3 and 7day-osteoblast culturing. However when cells were cultured for 14days, the amount of bone extracellular matrix was increased, on the experimental group. Conclusion: From these results, magnetic field of permanent magnetics might have effect on bone formation of osteoblast, especially at initial stage of implant placement. Therefore, their clinical application for implant or bone graft could be possible.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.383-392
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• 2016

This paper proposes the design considerations of resonant network and transformer magnetics for 500 kHz high switching frequency LLC resonant converter. The high power density can be effectively achieved by adopting high switching frequency which allows small size passive components in the converter. The design methodology of magnetizing inductance is derived for zero voltage switching (ZVS) condition, and the design methodology of the transformer and output capacitance is derived to achieve high power density at high operating frequency. Moreover, the structure of transformer is analyzed to obtain the proper inductance value for high switching operation. To verify the proposed design methodology, simulation and experimental results will be presented including temperature of passive and active components, and power conversion efficiency to evaluate dominant power loss. In addition, the validity of magnetics design will be evaluated with operating waveforms of the prototype converter.

• Journal of the Korean Magnetics Society
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• v.19 no.2
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• pp.74-79
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• 2009

We have investigated the magnetic education in elementary science of Korea. Text books and other related materials are analysed. Students learn playing with magnets in third grade and learn making electromagnets in sixth grade. Arrangement of topics are in accord with the historical development of electromagnetism in physics although the order is not well suited to other field of science. Teacher's guide books need to be developed to consider various environments in school such as city and country, and rich and poor town. Several details in the science textbook are pointed out for better education. Overall course looks sound.