• Proceedings of the Korean Magnestics Society Conference
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• 2013.05a
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• pp.21-22
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• 2013

• Journal of the Korean Magnetics Society
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• v.23 no.6
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• pp.179-183
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• 2013

The half-metallicity and magnetism for compounds of the $N_{(2-0.5n)}O_{0.5}nKCa$ (n = 0~4), which was based on the $d^0$ Heusler half-metals of $N_2KCa$ and $O_2KCa$, were investigated by means of first-principles band calculation method. From the calculated total magnetic moments and the density of states, we found that these three compounds have the half-metallicity. The magnetic moments of the N and O atoms in these compounds were considerably increased compared to those of pure $N_2KCa$ and $O_2KCa$. The K atoms have a large negative magnetic moments. The relationship between the value of magnetic moments for each atom and density of states are discussed.

• Journal of the Korean Magnetics Society
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• v.25 no.2
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• pp.31-38
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• 2015

Recently, a first-principles study led to a prediction that quaternary Heusler compounds, CoFeCrZ (Z = Ga, Ge) are excellent half-metallic ferromagnets. In this study, we investigate the electronic and the magnetic properties at the (001) surfaces of CoFeCrGa and CoFeCrGe by means of the full-potential linearized augmented plane wave (FLAPW) method within generalized gradient approximation. We considered two types of surface termination: CoFe-terminated and CrZ-terminated surfaces, Z being either Ga or Ge. From the calculated total magnetic moments and the local density of states, we found that half-metallicity is not preserved for all the surfaces. But the calculated atomic density of states showed that CrGa-terminated surface of the CoFeCrGa is almost half-metallic. The magnetic moment of the Co, Fe, or Cr atoms at the surface or subsurface layers in each system had very different values.

• Journal of the Korean Magnetics Society
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• v.22 no.4
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• pp.117-120
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• 2012

Compounds such as NaN belong to an interesting class of materials in which a magnetic order may appear despite the lack of d electrons. The magnetic properties of these materials are ascribed to the partially filled p shells. Recently, on the basis of electronic structure calculations from first principles, it has been found that NaN is a ferromagnetic half-metal in rocksalt (RS) and zinc-blende (ZB) structures with half-metallic band gaps in majority electron channels. The former structure has appeared to be more stable. From the first-principles calculation, we found that the half-metallic properties of the bulk RS and ZB NaN are conserved at the RS(001) and ZB(110) surfaces. Due to the interactions between Na s and N p electrons, N atoms become positively polarized. In the RS NaN (001) the calculated values of the magnetic moments of the N atoms is about $0.73{\mu}_B$. The magnetic moment on the N atom in the top most layer of ZB(110) is slightly larger than that of the RS(001) surface, i.e., $0.75{\mu}_B$. The Na atoms in the both structure are hardly polarized.

• Sim-seong Yeon-gu
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• v.32 no.2
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• pp.122-168
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• 2017

I tried to understand a folk tale "The half-boy" in terms of analytical psychology. In the story, a lady without children prayed to the Buddha. The white old man came and gave three fishes, but the cat ate half of it. So, she ate two and a half. She gave birth to two perfect sons. The third son had one arm, one leg, and one eye. They grew well. Brothers went to take the civil service examinations, and the half-boy followed. But two brothers did not like the half-boy coming along. So, brothers tied the half-boy to the rocks and trees, and he picked them up with force and gave them down to the yard of the house. And the half-boy followed his brothers again, and brothers tied him with kudzu and put him in front of the tiger. The half-boy won the tiger by betting with cutting kudzu. The half-boy stripped off the tiger's skin. The host coveted the tiger skin and they played with janggi. The half-boy won the game and was permitted to take host's daughter. The half-boy went with a string, a drum, a flea, and a bedbug. He teased host's people with these. The half-boy brought a virgin and lived well. "The Half-Boy" folktale is an old story spread throughout the country. There are similar stories in India and Africa. Unilateral figures are universally distributed archetypal images. In numerous cultures gods and spirits are being portrayed as unilateral figures. In the creation mythology, half-figure beings have immortality. In Indonesian and African folk tales, the half-born boy goes to heaven and merges with its half and becomes perfect. Some of one-sided spirits are harmful to humans but some of one-sided birds, chickens, and spirits are helpful to people. Sometimes half being is a cultural hero who steals grain from heaven or gets some advice how to use bamboo. There are stories that half body becomes a whole body afterwards. But in this folktale and most of the similar folktales, half-figure does not change and maintains half-figure to the end. And as a half-figure he does various great things and marries a virgin. The half-boy symbolizes a psychic experience born in the unconscious. The unconscious contents may seem strange and weird at first and the collective consciousness does not want to accept them. But the unconscious exerts greater power and brings vitality and creativity to consciousness. This folk tale seems to have compensated for the stubborn collective consciousness of our society, which was a Confucian class society. It also allows people to change their attitude toward disabled people and recognize strengths and creativity of the handicapped.

• Journal of the Korean Magnetics Society
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• v.17 no.4
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• pp.147-151
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• 2007

We have investigated the half-metallicity and magnetism for the Heusler ferromagnet $Co_2$ZrSi interfaced with semiconductor ZnTe along the (001) plane by using the full-potential linearized augmented plane wave (FLAPW) method. We considered low types of possible interfaces: ZrSi/Zn, ZrSi/Te, Co/Zn, and Co/Te, respectively. From the calculated density of states, it was found that the half-metallicity was lost at all the interfaces, however for the Co/Te system the value of minority spin density of states was close to zero at the Fermi level. These facts are due to the interface states, appeared in the minority spin gap in bulk $Co_2$ZrSi, caused by the changes of the coordination and symmetry and the hybridizations between the interface atoms. At the Co/Te interface, the magnetic moments of Co atoms are 0.68 and $0.78{\mu}_B$ for the "bridge" and "antibridge" sites, respectively, which are much reduced with respect to that ($1.15{\mu}_B$) of the bulk $Co_2$ZrSi. In the case of Co/Zn, Co atoms at the "bridge" and "antibridge" sites have magnetic moments of 1.16 and $0.93{\mu}_B$, respectively, which are almost same or slightly decreased compared to that of the bulk $Co_2$ZrSi. On the other hand, for the ZrSi/Zn and ZrSi/Te systems, the magnetic moments of Co atoms at the sub-interface layers are in the range of $1.13{\sim}1.30\;{\mu}_B$, which are almost same or slightly increased than that of the bulk $Co_2$ZrSi.

• Neonatal Medicine
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• v.16 no.2
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• pp.244-247
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• 2009

Thyroid hemiagenesis is a rare congenital anomaly in which one thyroid lobe fails to develop. Thyroid hemiagenesis usually does not cause clinical symptoms by itself, therefore, this anomaly is detected incidentally during the evaluation of other thyroid disorders. We describe a rare case of thyroid hemiagenesis in a 1-month-old female infant who presented with prolonged jaundice and abnormal laboratory findings of congenital hypothyroidism. The patient showed the characteristic features of thyroid hemiagenesis of the left lobe in Tc-99m pertechnetate scintigraphy and ultrasonography of the thyroid gland. The patient has improved with supportive care, including thyroid hormone replacement. Further long-term follow-up is required for the investigation of recurrence of thyroid abnormalities.

• Journal of the Korean Magnetics Society
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• v.18 no.5
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• pp.163-167
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• 2008

The electronic structure and magnetism of superlattice systems consisted of Heusler compound $Co_2MnSi$ (CMS) and zinc-blende MnAs (MA) are investigated by means of the all-electron full potential linearized augmented plane wave method within the generalized gradient approximation. Four superlattice systems are considered, that is CMS(m)/MA(n), where m and n, being either 2 or 4, denote the number of alternatingly arrayed layers of the compounds in a superlattice along [001] direction. From the calculated total magnetic moments as well as the total density of states, it is found that neither of the four systems is half-metallic. It is also found that the Mn atoms are antiferromagnetically coupled in the systems of CMS2/MA2 and CMS2/MA4. The total and atom-resolved density of states of the four superlattices are compared with those of the bulk $Co_2MnSi$ and MnAs, and the influences of the change in the systems symmetry on the magnetism and half-metallicity are discussed.

• Journal of the Korean Magnetics Society
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• v.18 no.4
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• pp.131-135
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• 2008

The electronic structures, magnetism, and half-metallicity of the full-Heusler $Co_2TiSn$(001) surfaces have been investigated by using the all-electron full-potential linearized augmented plane wave method within the generalized gradient approximation. We have considered both of the Co atoms terminated(Co-term) and the TiSn atoms terminated(TiSn-term) surfaces. From the calculated density of states, we found that the half-metallicity was destroyed at the surface of the Co-term, while the half-metallicity was retained at the TiSn-term. For the surface of the Co-term, due to the reduced coordination number the occupied minority d-states were shifted to high energy regions and that cross the Fermi level, thus destroy the surface half-metallicity. On the other hand the surface states at the surface of the TiSn-term were located just below the Fermi level, which reduces the minority spin-gap with respect to that of the center layer. The calculated magnetic moment of the surface Co atom for the Co-term was increased by 10 % to 1.16 ${\mu}_B$ with respect to that of the inner-layers, while the magnetic moment of the subsurface Co atom in the TiSn-term has almost same value of the innerlayers(1.03 ${\mu}_B$).

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.5
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• pp.113-119
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• 1998

Air spring has the advantages to be nearly constant in natural frequency inspite of load change, and to be able to control height level. Half-long taper spring has the advantages to function as well link as spring. Thus to utilize two type spring's advantages, half-long taper spring and air spring are combined and used. In this study, the theory to calculate the characteristics in combination is developed.