• Journal of the Semiconductor & Display Technology
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• v.20 no.1
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• pp.12-17
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• 2021

The electronic and magnetic properties for Mn-adsorbed on the chalcopyrite (CH) AlGaP2 semiconductor are investigated by using first-principles FPLMTO method. The clean CH-AlGaP2 without adsorbed Mn is a p-type semiconductor with a direct band-gap. The Mn-adsorbed CH-AlGaP2 exhibits the ferromagnetic state. It is more energetically stable than the other magnetic ones. The interstitial site on P-terminated surface is more energetically favorable one than the Al/Ga-terminated surface, or the other adsorbing sites. In the case of Mn-adsorbed Al/Ga-terminated surface, it is induced a strong coupling between Mn-3d and neighboring P-3p electrons. The holes of partially unoccupied minority Mn-3d state and majority (or minority) Al-3p or P-3p state are induced. Thus a high magnetic moment of Mn is sustained by holes-mediated double-exchange coupling. It is noticeable that the semiconducting and half-metallic characteristics of CH-AlGaP2:Mn thin film is disappeared.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.611-617
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• 2021

The mechanical properties of α-Na₃(U_0.84(2),Na_0.16(2))O₄ have been researched using the first-principles calculations combined with the quasi-harmonic Debye model. The obtained lattice parameters agree well with the published experimental data. The results of elastic constants indicate that α-Na₃(U_0.84(2),Na_0.16(2))O₄ is mechanically stable. The polycrystalline moduli are predicted. The results show that the α-Na₃(U_0.84(2),Na_0.16(2))O₄ exhibits brittleness and possesses obvious elastic anisotropy. The hardness shows that it can be considered a "soft material". Furthermore, the Debye temperature θ_D and the minimum thermal conductivity k_min are also discussed, respectively. Finally, the thermal expansion coefficient α, isobaric heat capacity C_P and isochoric heat capacity C_V are evaluated through the quasi-harmonic Debye model.

• Journal of Korean Classical Literature and Education
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• no.15
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• pp.113-138
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• 2008

Because of difference of syntactic construction, Lee dong- baek's divides into two parts. Though each parts show different principles of thinking, they aim same communicational purpose. The first half of that quotes set phrase of Chinese classical literature and folklore shows principles of expression that represent object by present cultural well-acquainted informations. It reflects process of thinking basing on cultural identity in pursuit of harmonious communication with listener. In the latter half of the work, the object is presented by mimesis and sensuous description. It implicates intention of making correspondence between linguistic sign and object, and shows principles of expression that present more directly by strengthening the motivated between sign and object. Based on discussion above, I hope we will find a clue to make contents of Korean expression education. We will convert these principles of pursuing cultural universality to make sympathy in communication and pleasure of that, or of representing object substantially to make correspondence into the contents of Korean expression education.

• Journal of architectural history
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• v.14 no.3 s.43
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• pp.103-118
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• 2005

This study is about the meaning of wooden brackets that are distinctive elements of wooden architecture in Korea, Japan, and China. Existing studies about wooden brackets have been limited to the boundary of formalism, so the object of this study is to make a breakthrough in the field of those studies. The Wooden brackets in this study are considered to be decorative elements, and the principles of their design are examined. The specific subject of the study is wooden architecture with Jusimpo-styled brackets that have brackets only on pillars. The definition of Jusimpo is reexamined first, and ChulMok-Ikkong which has not been regarded as a Jusimpo-styled wooden bracket is interpreted as Jusimpo-styled one in this study. Categorized into three types, Jusimpo is examined how it is expressed according to the type of the roof in a building. In view of the results, the wooden bracket system is an effective technique to express the formality, and two designing principles can be seen in Jusimpo; one that wooden brackets observed externally are standardized and regarded as the same ones, and the other that the style of wooden brackets used in the most formal building is Yi-ChulMok. These designing principles mean that the carpenter who was in charge of building the architecture had certain principles when expressing wooden brackets as well as the roofs according to the class of the architecture. In addition, although the styles of wooden brackets that were used in the most formal architecture during the Chosun period were mostly Dapo, Jusimpo in the form of Yi-ChulMok was also adopted in some temples depending on their scale, and that means Jusimpo-styled wooden brackets were never considered to be inferior to Dapo-styled ones. And this point leaves the argument that the reexamination of Jusimpo-styled wooden brackets which have been regarded as the style used in the attached building or small structures since the Choun dynasty should be conducted.

• The Journal of Korea CHUNA Manual Medicine
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• v.3 no.1
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• pp.85-96
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• 2002

Objectives : The purpose of this study is to get knowledge about osteopathy and to applicate the osteopathy to oriental medicine. Methods: We investigated several books and literatures on osteopathy related sites explored by internet to know the general theories and present conditions of osteopathy in Korea and other countries. Results & Conclusion : 1. The principles of osteopathy are as follows. First, the human being is a dynamic unit of function. Second, the body possesses self regulating mechanisms which are self healing in nature. Third, structure and function are reciprocally interrelated. Fourth, the body rational therapy is based upon knowledge and use of the above three principles. 2. Doctors of osteopathy evaluate the musculoskeletal system to identify structural problems and to support the body's natural tendency toward health and self healing. 3. We can applicate the osteopathy to oriental clinical medicine based on interpreting the principles of osteopathy.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.6
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• pp.444-448
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• 2010

Based on first-principles calculations, we study the magnetic properties of Co, Ni, Fe, V, and Mn impurities in ZnO. The stabilities of the ferromagnetic state and the magnetic moment of each impurity largely depend on the amount of doped electron or hole. For lightly doped n-type ZnO, it is found that the doping of Ni ions is the most effective for inducing ferromagnetism, while Fe ions show the most stable ferromagnetic couplings for heavily doped n-type samples. The characteristics of the magnetic interactions of Co ions are similar with those of Fe ions, but Co ions require much larger amount of doped electron than Fe ions to show the ferromagnetic couplings. The ferromagnetic coupling between Mn and V ions is unstable in n-type conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.8
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• pp.733-738
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• 2009

Mechanical properties of <001> silicon nanowires are presented. In particular, predictions from the calculations based on different length scales, first principles calculations, atomistic calculations, and continuum nanomechanical theory, are compared for <001> silicon nanowires. There are several elements that determine the mechanics of silicon nanowires, and the complicated balance between these elements is studied. Specifically, the role of the increasing surface effects and reduced dimensionality predicted from theories of different length scales are compared. As a prototype, a Tersoff-based empirical potential has been used to study the mechanical properties of silicon nanowires including the Young's modulus. The results significantly deviates from the first principles predictions as the size of wire is decreased.

• Journal of Magnetics
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• v.14 no.1
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• pp.1-6
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• 2009

The magnetic properties of ${Bi_x}{Ca_{1-x}}{MnO_3}$ for x = 0.12, 0.13, 0.14, 0.15, and 0.16 were examined by measuring magnetic susceptibility, resistivity and electron magnetic resonance at different temperatures. ${Bi_x}{Ca_{1-x}}{MnO_3}$ showed complicated magnetic structure that varies with temperature and composition, particularly around Bi composition x. 0.15. The aim of this study was to determine how the magnetic and physical properties of ${Bi_x}{Ca_{1-x}}{MnO_3}$ change in this region. In addition, first principles calculations of the magnetic phase of ${Bi_x}{Ca_{1-x}}{MnO_3}$ for x = 0, 0.125, 0.25 were carried out, and the spin state, electric and magnetic characteristics are discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.6
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• pp.510-514
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• 2011

Based on first-principles LCAO method, we study the electronic and atomic structures of DNA nucleobases adenine (A), thymine (T), guanine (G), and cytosine (C) adsorbed on graphene surfaces. The ${\pi}-{\pi}$ stacking interactions between graphene and nucleobases lead to the bilayer geometries similar to the Bernal stacked graphite. Through the density of states and charge density analyses, it is found that nucleobases are physisorbed on graphene by dispersive interactions with negligible charge exchange. Our calculations reproduce the atomic structures obtained in previous plane wave calculations accurately with much less computation, and well describe the delocalized ${\pi}-{\pi}$ interactions in graphene-nucleobases system, indicating that the LCAO method is very efficient for investigating graphene-bio systems.

• Journal of Preventive Medicine and Public Health
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• v.54 no.5
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• pp.360-369
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• 2021

Objectives: The purpose of this study was to investigate public preferences regarding allocation principles for scarce medical resources in the coronavirus disease 2019 (COVID-19) pandemic, particularly in comparison with the recommendations of ethicists. Methods: An online survey was conducted with a nationally representative sample of 1509 adults residing in Korea, from November 2 to 5, 2020. The degree of agreement with resource allocation principles in the context of the medical resource constraints precipitated by the COVID-19 pandemic was examined. The results were then compared with ethicists' recommendations. We also examined whether the perceived severity of COVID-19 explained differences in individual preferences, and by doing so, whether perceived severity helps explain discrepancies between public preferences and ethicists' recommendations. Results: Overall, the public of Korea agreed strongly with the principles of "save the most lives," "Koreans first," and "sickest first," but less with "random selection," in contrast to the recommendations of ethicists. "Save the most lives" was given the highest priority by both the public and ethicists. Higher perceived severity of the pandemic was associated with a greater likelihood of agreeing with allocation principles based on utilitarianism, as well as those promoting and rewarding social usefulness, in line with the opinions of expert ethicists. Conclusions: The general public of Korea preferred rationing scarce medical resources in the COVID-19 pandemic predominantly based on utilitarianism, identity and prioritarianism, rather than egalitarianism. Further research is needed to explore the reasons for discrepancies between public preferences and ethicists' recommendations.