• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.116-122
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• 1997

The audible noise produced by corona discharge in high voltage transmission lines is the most important line design consideration. In this paper, more accurate and useful formulas for predicting the A-weighted audible noise during heavy and light rain in alternative current (AC) transmission lines are proposed through comparison with the existing formulas. The proposed formulas are developed by the applications of evolutionary computations (ECs) to audible noise data base from long-term measurement.

• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.749-753
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• 1996

The rotationally cooled but electronically excited m-xylyl radical has been generated in a jet from the gas mixture of precursor m-xylene and buffer gas He by a technique of corona excited supersonic expansion. The visible vibronic emission spectra in the transition of 12A2→12B2 of m-xylyl radical in the gas phase have been recorded using a Fourier transform spectrometer. The spectra have been analyzed for the assignments of the vibrational frequencies in the electronic ground state with combination of the torsional frequencies reported previously.

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1285-1288
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• 1997

The graphite tube nozzle has been developed for the generation of metastable He jet by which the nitrogen molecules initially excited in a jet with Engelking type nozzle have been further excited in a corona excited supersonic expansion. The excitation process of nitrogen molecules in the jet collision has been discussed in detail by observing the emission intensity from the vibronic emission spectra of nitrogen molecules and nitrogen molecular ions upon helium jet collision.

• Bulletin of the Korean Chemical Society
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• v.19 no.12
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• pp.1359-1363
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• 1998

The p-fluorobenzyl radical was generated from the p-fluorotoluene and vibronically excited in a corona excited supersonic expansion with inert buffer gases. The vibronic emission spectra of the jet cooled p-fluorobenzyl radical in the D1 → D0 transition have been observed in the visible region. The spectra exhibit several low frequency sequence bands in the vicinity of the every strong vibronic band. The characteristics of the sequence bands have been examined by varying the experimental conditions such as carrier gas and nozzle size to identify the origin of the transition in the spectra.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.211-216
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• 2000

In this paper, experimental investigations were carried out to remove NOx, SOx simultaneously from a simulated combustion flue gas [$NO(0.02%)-SO_2(0.08%)-CO_2-Air-N_2$] by using a pulse corona induced plasma chemical processing. Discharge domain of wire-cylindrical plasma reactor was separated from a gas flow duct to avoid unstable discharge by aerosol particle deposited on discharge electrode and grounded electrode. The NOx, SOx removal was experimentally investigated by a reaction induced to ammonium nitrate, ammonium sulfate using a low price of aqueous NaOH solution and a small quantity of ammonia. Volume percentage of aqueous NaOH solution used was 20% and $N_2$ flow rate was $2.5{\ell}/min$ for bubbling aqueous NaOH solution. Ammonia gas(l4.82%) balanced by argon was diluted by air and was introduced to a main simulated flue gas duct through $NH_3$ injection system which was in downstream of reactor. The $NH_3$ molecular ratio(MR) was determined based on [$NH_3$] and [$NO+SO_2$]. MR is 1.5. The NOx removal rates increased in the order of DC, AC and pulse, but SOx removal rates was not significantly effected by source of electricity. The NOx removal rate slightly decreased with increasing initial concentration. but SOx removal rate was not significantly affected by initial concentration. The NOx, SOx removal rates decreased with increasing gas flow rate.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.479-486
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• 2009

We studied the solar proton events (SPEs) associated with coronal mass ejections (CMEs) during the solar cycle 23 (1997-2006). Using 63 SPE dataset, we investigated the relationship among SPE, flare, and CME, and found that (1) SPE rise time and duration time depend on CME speed and the earthward direction parameter of the CME, and (2) the SPE peak intensity depends on CME speed and X-ray Flare intensity. While inspecting the relation between SPE peak intensity and the direction parameter, we found there are two groups: first group consists of large six SPEs (> 10,000 pfu at > 10 MeV proton channel of GOES satellite) and shows strong correlation (cc = 0.65) between SPE peak intensity and CME direction parameter. The second group has a weak intensity and shows poor correlation between SPE peak intensity and the direction parameter (cc = 0.01). By investigating characteristics of the first group, we found that all the SPEs are associated with very fast halo CME (> 1400km/s) and also they are mostly located at central region and within ${\pm}20^{\circ}$ latitude and ${\pm}30^{\circ}$ longitude strip.

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.181-187
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• 1999

We prepared the side-chain type nonlinear optical NPP(N-(6-nitrophenyl)-(L)-prolinol) polymer films by spin coating method. Ellipsometric spectra were in situ collected by using spectroscopic phase modulated ellipsometer while the NPP polymer films were being corona poled at the temperature above glass transition. We calculated film thickness and the refractive index dispersion by modeling the spectro-ellipsometry data in transparent region. We also calculated the refractive index and the extinction coefficient of the polymer films by numerically inverting the spectro-ellipsometry data in absorbing region, while the previously determined film thickness was used. The independently determined extinction coefficient spectra from the analysis of transmission spectra were compared with those by spectro-ellipsometry and they showed an excellent agreement with each other. From the analysis of the complex refractive index change of the NPP polymer thin films induced by the corona poling, we could determine the vertical complex refractive index and the horizontal complex refractive index separately. Using the volume fraction of the vertical component f⊥, the degree of poling of poled NPP polymer films was quantitatively addressed. It is suggested that the present method can be used to quantitatively address the degree of poling in an absolute manner and to depth profile the poled fraction of thick polymer films. It will be useful to understand the structural change of polymer films and hence the poling mechanism during the poling process.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.432-438
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• 2021

This dissertation's object is to confirm the drastic popularity of La Peste of Albert Camus in Korea post-corona society using big data as the mean of inductive research. Analyzing news articles concerning Camus and investigating word frequency of the book La Peste will affirm the implications La Peste has on current Korea society as the outbreak spreads. As an analysis tool, Bigkinds of Korea Press Foundation and Nuagedemots, the French version of Word Cloud were used. For the past 30 years, Albert Camus has been known in Korea as the writer of L'étranger, but after the epidemic, he earned more reputation with La Peste. Compared to L'étranger that rebelled against the world's absurdity with ennui, La peste emphasizes the importance of resistance accompanied by solidarity. La peste conveys hope by depicting disastrous situations of citizens who confront the plague by organizing a health college. The novel delivers a lot of ethical inspiration to humanity in this exceptional circumstance of COVID-19.

• Journal of Christian Education in Korea
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• v.71
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• pp.341-370
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• 2022

As COVID-19 has been converted to an endemic with social distancing lifted, people are getting used to new cultures and lifestyles that are different from before. While the world is now adapting to rapidly changing trends, Christian education is facing a crisis without being able to respond to these changes. Therefore, a new Christian education method is now required. The purpose of this study is to suggest a new Christian education method that allows Christians to properly lead a new era as an alternative to Christian education that is experiencing such a crisis. The study also presents the metaverse Christian education platform, which is a detailed and practical method of Christian education, by incorporating the platform and metaverse that are under the spotlight in the post-Corona era into Christian education. Here, the christian educational platform refers to the system, space, and various materials that can make Christian education efficient and smooth. The metaverse Christian education platform consists of 4 stages according to the size of the platform to activate supply and demand within the platform. Stage 1 is a home education platform, Stage 2 is a community education platform, Stage 3 is a regional union education platform, and Stage 4 is an educational mission platform. The last Stage 4, the educational mission platform utilized the metaverse, which is drastically expanding in the present era, as a method of educational mission. It is meaningful that the educational mission has been embodied by providing small churches and the next generation in underdeveloped countries with educational contents, educational materials, online mentors, virtual communities, and real-time educational broadcasts within the educational platform, using virtual spaces in the metaverse.

• Journal of Welding and Joining
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• v.35 no.1
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• pp.34-42
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• 2017

This paper presents a comparative study of the AC and MFDC resistance spot welding process with consideration of sheet thickness. The previous studies have confirmed that there is difference in the optimum welding current and expulsion current with AC and MFDC. The aim of this study was revealing the effect of sheet thickness on weldable current range and expulsion behavior for AC and MFDC welding processes. The optimum welding current of AC was lower (1.6 kA) than MFDC welding process in 0.8 mm sheet thickness. Early nugget growth being caused by the peak current of AC developed weld interface deformation, which resulted in suppressing the growth of corona bond and occurrence of low current expulsion. The resistance spot welding for thicker sheet (1.4 mm) required lower current of 0.6 kA for the expulsion on the MFDC welding process. The growth of contact diameter (size of corona bond) and button diameter was linear up to the expulsion current with MFDC welding process. Therefore, more attention is required when the AC and MFDC resistance spot welding process is applied for different thickness of steel sheet combination for automotive application.