• Journal of the Korean Magnetics Society
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• v.15 no.2
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• pp.153-161
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• 2005

• Journal of the Korean Magnetics Society
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• v.10 no.5
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• pp.256-267
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• 2000

• Journal of the Korean Magnetics Society
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• v.14 no.6
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• pp.240-248
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• 2004

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.1-3
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• 2000

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.189-190
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• 2000

• Journal of the Korean Magnetics Society
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• v.27 no.3
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• pp.104-113
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• 2017

K. Suwab, a chairman of the World Economic Forum (WEF), reported the emerging of the $4^{th}$ industrial revolution by the convergence of artificial intelligence and robot as well as the fusion of true and virtual reality in the WEF 2016. He suggested the $4^{th}$ industrial revolution would change greatly the paradigm of industry and society in the future, and damage the security and quality of the human job severely. In this review the argument of terminology, the impacts on economics, industry technologies and jobs by the $4^{th}$ industrial revolution have been discussed. And the role of magnetics on the 2-4th industrial revolutions was reviewed briefly.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.663-666
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• 1995

The domain wall motion coercivity, $H_{c}$, of magnetic materials arises from the dependence of the wall energy on localized changes in material parameters (magnetization, anisotropy, exchange energy densities). However, in an otherwise perfectly homogeneous material, the domain wall energy might change due to the change in the volume of the wall versus the wall position. Thus, any surface roughness contributes to the coercivity. Assuming different two-dimensional surface profiles, characterized by average wavelengths ${\lambda}_{x}$ and ${\lambda}_{y}$, and relative thickness variations dh/h, the coercivity due to the surface roughness has been calculated. Compared to the one dimensional case, the 2D coercivity is reduced. Depending on the ratio of ${\lambda}$ to the domain wall width, $H_{c}$ has a maximum around 2, and increasing with dh/h. With the decreasing thickness of the thin film and GMR heads, it might be the domain factor in determining the coercivity.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.310-310
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• 2003

• Journal of the Korean Magnetics Society
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• v.12 no.3
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• pp.117-126
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• 2002

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.399-403
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• 1995

The prospects for further improvement in the energy product of permanent magnets are discussed. Some current research directions, including artificial nanostructures, nitride magnets and novel flux sources are briefly reviewed.