• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.317-317
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• 2011

Enhanced ICRF (Ion Cyclotron Range of Frequency) ion heating of H-mode D(H) plasma will be tried in 2011 KSTAR experimental campaign. Minority heating is a main ion heating scheme in the ICRF. Its efficiency increases as the hydrogen minority ratio increases in deuterium plasmas. And it should be sustained at a lower level than the critical minority ratio. Consequently, it is important to elevate the critical ratio to maximize ion heating and it is possible by increasing the ion temperature or parallel wave number (k${\parallel}$) of the antenna. Increasing the k${\parallel}$ is not a good approach since the coupling efficiency decreases exponentially with regard to k${\parallel}$ as well. So the remaining method is to increase ion temperature by using NB (Neutral Beam). Ion heating fraction of NB increases as the electron temperature increases. Therefore, we will try to heat electron by using ECH together with NB ion heating before ICRF power injection. The ICRF heating efficiency will be compared with respect to several NB+ECH+ICRF heating combinations through several diagnostics such as XICS (Xray Imaging Crystal Spectroscopy), CES (Charge Exchange Spectroscopy) and neutron measurement. The theoretical background and the experimental results will be presented in more detail in the conference.

• Journal of Korean Library and Information Science Society
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• v.53 no.4
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• pp.233-266
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• 2022

The purpose of this study is to derive and propose agenda to improve the quality of minority services provided by regional cental libraries at the present time when information gap is deepening. First, text mining and topic modeling were conducted on 144 studies in the field of library and information science that dealt with minorities, and the discussions surrounding minorities in the domestic library world were examined in detail. Next, the current status of services for minorities in Regional central libraries were examined in detail, and tasks requiring discussion were sought in planning and operation of services for minorities in Regional central libraries. To this end, interviews were conducted with practitioners, in charge of services for minorities at Regional central libraries. Specifically, 1) awareness of minorities by practitioners, 2) current status of minority services, and 3) responsibility and role of Regional central libraries for planning and operating minority services and necessary support were analyzed. Based on the analysis results, the following tasks were derived. 1) Recategorization of minority groups, 2) Establishment of reference resource, 3) Reinforcement of education, and 4) Cooperation support between regional representative libraries and local public libraries were derived and suggested.

• Journal of the Korean Society of Costume
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• v.67 no.3
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• pp.66-80
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• 2017

The headdress is one of the most important clothing characters in China, as it was used to distinguish the 55 minority groups in China. Each minority group has a unique headdress culture. Among the 55 minority groups, the Zang, the Yi, and the Miao focus their ethnic costumes on the headdress, and have a more distinctive headdress culture compared to be other nationality groups. The Yi is one of the minority groups that linvd in Southwest China. They usually lived in compact communities in Sichuan, Yunnan, and Guizhou provinces, as well as the Guangxi Zhuang Autonomous region. The total population of the Yi is the sixth largest among the 55 minority groups. Modern scholars believe that the Yi people are descendants of the ancient Qiang people, which is a group that lived in Northwest China six or seven thousand years before. It is believed that the Qiang went down to the southern part of China and allied with the aboriginals in that region, and this group of people became the Yi, Due to its long history, cultural background, and the large number of people and settlements, they have produced a unique costume culture. The women's headdress culture is considered to be the one of the most important characteristics of their costume culture. There are four forming element of the Yi women's headdress, religious faith, myths, geographical distribution and customs & festivals. The first three elements play an important role in the protection and spread of headdress, while the fourth element provides potential for the modern headdress development. Because of much influence factors, more than 100 types of Yi women headdresses have developed. Depends on categories, Yi woman headdress can be divided into kerchief, hat, fascinator and other accessories wore on the hand. This study investigated the development of the Yi women's headwear, and screened and analyzed representative Yi women accessories, such as the headscarf, hat, and fascinator. This analysis will provide basic materials for further studies of Yi women's headdress or costume.

• Journal of the Korean association of regional geographers
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• v.14 no.5
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• pp.627-641
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• 2008

There have been frequent reorganizations of administrative areas and place-names in China since 1949. These reorganizations were practiced with the two institutions 'city control over surrounding counties(shiguanxianzhi)' and 'county transform to city(shigaixian)' based on the socialist commodity supply system(gongxiaozhidu) and civil registration system(hukouzhidu). In this article I will try to discuss the influence and meaning of these reorganizations on the minority nationalities districts in frontier China. The Conclusions are as follows: The increase of the number of cities and the reorganization of the place-names in the minority nationalities districts is not the result of the increase of population or advancement of industrial structure but the result of Han people having non agriculture registration(feinongyehukou) population's increase. Therefore the reorganizations of administrative areas and place-names was a process of inclusion of the minority nationalities areas as a part of the Chinese territory(guotu) more perfective than before.

• Journal of Magnetics
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• v.7 no.4
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• pp.132-137
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• 2002

The electronic structures and magnetism of the non-oxide perovskite MgCFe$_3$(001) surface were investigated by using the all-electron full-potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation (GGA). We considered both of the MgFe terminated (MgFe-Term) and the CFe terminated (CFe-Term) surfaces. We found that the minority spin d-bands of Fe(S) of the MgFe-Term are strongly localized and Fermi level (EF) lies just below the sharp peak of the minority spin d-band of Fe(S), while the minority spin d-bands of Fe(S) of the CFe-Term are not localized much and Fermi level (E$_F$) lies in the middle of two peaks of the minority spins. The majority Fe(S) d-band width of MgFe- Term is narrower than that of the CFe-Term. It is found that the magnetic moment of Fe(S) of the MgFe- Term is 2.51 ${\mu}$$_B$, which is much larger than that of 1.97 ${\mu}$$_B$ of the CFe-Term.

• Journal of Radiation Protection and Research
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• v.48 no.3
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• pp.124-130
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• 2023

Background: When bipolar junction transistors (BJTs) are used as switches, their switching characteristics can be deteriorated because the recombination time of the minority carriers is long during turn-off transient. When BJTs operate as low frequency switches, the power dissipation in the on-state is large. However, when BJTs operate as high frequency switches, the power dissipation during switching transients increases rapidly. Materials and Methods: When silicon (Si) BJTs are irradiated by fast neutrons, defects occur in the Si bulk, shortening the lifetime of the minority carriers. Fast neutron irradiation mainly creates displacement damage in the Si bulk rather than a total ionization dose effect. Defects caused by fast neutron irradiation shorten the lifetime of minority carriers of BJTs. Furthermore, these defects change the switching characteristics of BJTs. Results and Discussion: In this study, experimental results on the switching characteristics of a pnp Si BJT before and after fast neutron irradiation are presented. The results show that the switching characteristics are improved by fast neutron irradiation, but power dissipation in the on-state is large when the fast neutrons are irradiated excessively. Conclusion: The switching characteristics of a pnp Si BJT were improved by fast neutron irradiation.

• Journal of the Korean Society of Costume
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• v.42
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• pp.25-42
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• 1999

This study aims to prove that the fact that minority races in the north-eastern region contributed sable skin to the Quing Dynasty might be related to Cho-Sun of King Muryong in the Warring states period because documents are available here and there. The Chinese had been using fur clothing since ancient times but we cannot find any mention that they had used sable skin. This fact shows that sable skin was not widely used because of its rarity. Cho-pi had been used in making costume on a large scale from the period of the Han Dynasty to the end of the Quing Dynasty. Cho-pi was very rare and it was used as a measure of bartering. China met the demand of cho-pi by the Cho-pi contributions of the frontier minority races. It might bwe that the high demand of Cho-pi in the Quing Dynasty forced minority races to contribute Cho-pi The documents concerning Cho-pi in the north-eastern region are of great importance not only to the history of costume but also to the history of ancient economy and national culture.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.27-34
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• 1999

We investigated the effect of mechanical back side damage in viewpoint of electrical and surface morphological characteristics in Czochralski silicon wafer. The intensity of mechanical damage was evaluated by minority carrier recombination lifetime by laser excitation/microwave reflection photoconductance decay technique, atomic force microscope, optical microscope, wet oxidation/preferential etching methods. The data indicate that the higher the mechanical damage degree, the lower the minority carrier lifetime, and surface roughness, damage depth and density of oxidation induced stacking fault increased proportionally.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.4
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• pp.111-115
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• 2015

To improve the efficiency of the Si solar cell, high minority carrier life time is required. Therefore, the passivation technology is important to eliminate point defects on the silicon surface, causing the loss of minority carrier recombination. PECVD or post-annealing of thermally-grown $SiO_2$ is commonly used to form the passivation layer, but a high-temperature process and low thermal stability is a critical factor of low minority carrier lifetime. In this study, atomic layer deposition was used to grow the $Al_2O_3$ passivation layer at low temperature process. $Al_2O_3$ was selected as a passivation layer which has a low surface recombination velocity because of the fixed charge density. For the high charge density, an improved minority carrier lifetime, and a low surface recombination, nitrogen was doped in the $Al_2O_3$ thin film and the improvement of passivation was studied.

• Korean Journal of Materials Research
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• v.27 no.2
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• pp.107-112
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• 2017

The BCBJ (Back Contact and Back Junction) or back-lit solar cell design eliminates shading loss by placing the pn junction and metal electrode contacts all on one side that faces away from the sun. However, as the electron-hole generation sites now are located very far from the pn junction, loss by minority-carrier recombination can be a significant issue. Utilizing Medici, a 2-dimensional semiconductor device simulation tool, the interdependency between the substrate thickness and the minority-carrier recombination lifetime was studied in terms of how these factors affect the solar cell power output. Qualitatively speaking, the results indicate that a very high quality substrate with a long recombination lifetime is needed to maintain the maximum power generation. The quantitative value of the recombination lifetime of minority-carriers, i.e., electrons in p-type substrates, required in the BCBJ cell is about one order of magnitude longer than that in the front-lit cell, i.e., $5{\times}10^{-4}sec$ vs. $5{\times}10^{-5}sec$. Regardless of substrate thickness up to $150{\mu}m$, the power output in the BCBJ cell stays at nearly the maximum value of about $1.8{\times}10^{-2}W{\cdot}cm^{-2}$, or $18mW{\cdot}cm^{-2}$, as long as the recombination lifetime is $5{\times}10^{-4}s$ or longer. The output power, however, declines steeply to as low as $10mW{\cdot}cm^{-2}$ when the recombination lifetime becomes significantly shorter than $5{\times}10^{-4}sec$. Substrate thinning is found to be not as effective as in the front-lit case in stemming the decline in the output power. In view of these results, for BCBJ applications, the substrate needs to be only mono-crystalline Si of very high quality. This bars the use of poly-crystalline Si, which is gaining wider acceptance in standard front-lit solar cells.