• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.359-361
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• 2001

In this paper, 3-dimensional charge simulation method was applied to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise in a corona cage. We found calculation error of this method was w a reasonable boundary of 0.5%.

• Electrical & Electronic Materials
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• v.10 no.8
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• pp.830-835
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• 1997

In this study an experimental investigation has been conducted to remove NOx and SO$_2$simultaneously from a combustion flue gases were consisted of NO-SO$_2$-$CO_2$-$N_2$-O$_2$([NO]o:200ppm and [SO$_2$]o:800ppm) and the injection gases used as radical source gases were NH$_3$-Ar-air and CH$_4$-Ar-air. NOx and SO$_2$removal efficiency and the other by-products were measured by Fourier Transform Infrared(FTIR) as well as SO$_2$, NOx and NO$_2$gas detectors. and SEM images after sampling. The results showed that a significant Nucleating Particle Counter(CNPC) and SEM images after sampling. The results showed that a significant aerosol particle formation was observed during a simultaneous NOx and SO$_2$removal operation in corona radical shower systems. The diameter of aerosol particles was in the range of 0.18 to 3.6${\mu}{\textrm}{m}$ with a maximum fraction of particles at particles diameter of 1${\mu}{\textrm}{m}$. The NOx removal efficiency significantly increased with increasing applied voltage and NH$_3$molecule ratio. The SO$_2$removal efficiency was not significantly effected by applied voltage and slightly increased with increasing NH$_3$molecule ratio. It could be found that it is possible to use CH$_4$for NOx and SO$_2$removal by corona radical shower systems.

• Journal of Convergence for Information Technology
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• v.12 no.3
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• pp.116-125
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• 2022

The purpose of this study is to analyze whether investor anxiety caused by COVID-19 affects cryptocurrency prices in the COVID-19 pandemic, and to experiment with cryptocurrency price prediction based on a deep learning model. Investor anxiety is calculated by combining Naver's Corona search index and Corona confirmed information, analyzing Granger causality with cryptocurrency prices, and predicting cryptocurrency prices using deep learning models. The experimental results are as follows. First, CCI indicators showed significant Granger causality in the returns of Bitcoin, Ethereum, and Lightcoin. Second, LSTM with CCI as an input variable showed high predictive performance. Third, Bitcoin's price prediction performance was the highest in comparison between cryptocurrencies. This study is of academic significance in that it is the first attempt to analyze the relationship between Naver's Corona search information and cryptocurrency prices in the Corona phase. In future studies, extended studies into various deep learning models are needed to increase price prediction accuracy.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.8
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• pp.1062-1068
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• 2002

In our previous study, it was proven that the mean size and the total number concentration of carbon soot particles emitted from a $C_2$H$_4$ normal diffusion flame decreased when a DC corona was discharged to pin-pin electrodes. In this work the effect of AC corona discharge on soot emission was investigated and compared with that of DC corona discharge. For the pin-pin electrodes the size of soot particles and the number concentration decreased by the AC voltage. There were only slight changes in size distribution with frequencies, while the magnitude of applied voltage was constant. When the electric field was applied to plate-plate electrodes, the size and the number concentration also decreased with the applied AC voltages. For applied voltages above 2kV the effect of frequency increase on the soot emission was effective.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.980-982
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• 1992

This paper deals with the dielectric behaviors of $SF_6$ gas and prebreakdown growth caused by lightning impulse voltages In inhomogeneous field perturbed with a fixed needle-shaped protrusion on the electrode. The measuring interpretation of the external current induced by moving charges is described. The temporal growth of prebreakdown is observed by using a shunt and photomultiplier. The prebreakdown processes are initiated by the first streamer corona at a needle protrusion, the flashover of the main gap in the positive polarity is very sensitive to the local field and propagates into the gap with the leader mechanism. It Is found that the dependence of the prebreakdown phenomena on the polarity of applied voltages is caused by the effect of space charges. In addition, the proposed measuring techniques are very useful to perform the measurements of avalanche currents, corona discharges in inhomogeneous fields and partial discharges in voids.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.12
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• pp.77-82
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• 2015

Ozone is a powerful disinfectant and oxidizing agent, and it is used in a wide range of applications, such as waste water treatment, food processing, etc.. There is also a great potential of using ozone in new emerging medical applications, such as ozone dentistry and ozone oxygen therapy. For these purposes, simple, small, compact and efficient sources of ozone are needed. In this study, in order to increase the current-voltage range of the discharge and to avoid the overheating of the gas in the ozonizer we suggested ozonizer of injection needle and plate electrode type(INP Type) with the gas through the needle. A ozonizer of INP type have been investigated by focusing on ozone concentration and yield according to flow rates and Gap of two electrodes. The results of studies of ozone production for DC corona discharge in oxygen at atmospheric pressure about the ozonizer of INP type. The ozone concentration and the generation yield increased as the gap of two electrodes and gas flow were decreased. Also, when the gap of two electrodes and gas flow with no change, the ozone concentration and generation yield each have variation of direct proportion and inverse proportion with discharge voltage.

• Biomedical Science Letters
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• v.28 no.4
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• pp.211-222
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• 2022

After more than two years of efforts to end the corona pandemic, a gradual recovery is starting in countries with high vaccination rates. Easing public health policies for a full-fledged post-corona era, such as lifting the mandatory use of outdoor mask and quarantine measures in entry have been considered in Korea. However, the continuous emergence of new variants of SARS-CoV-2 and limitations in vaccine efficacy still remain challenging. Fortunately, T cells and memory T cells, which are key components of adaptive immunity appear to contribute substantially in COVID-19 control. SARS-CoV-2 specific CD4⁺/CD8⁺ T cells are induced by natural infection or vaccination, and rapid induction and activation of T cells is mainly associated with viral clearance and attenuated clinical severity. In addition, T cell responses induced by recognition of a wide range of epitopes were minimally affected and conserved against the highly infectious subsets of omicron variants. Polyfunctional SARS-CoV-2 specific T cell memory including stem cell-like memory T cells were also developed in COVID-19 convalescent patients, suggesting long lasting protective T cell immunity. Thus, a robust T-cell immune response appears to serve as a reliable and long-term component of host protection in the context of reduced efficacy of humoral immunity and persistent mutations and/or immune escape.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.509-514
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• 2021

The pandemic of COVID-19 is driving the demand for non-face-to-face diagnosis, observation, and treatment in the healthcare environment, which has led to increased interest in helathcare robots. The authors intend to predict the direction in which the quarantine healthcare robots should be utilized in the post-corona era through analysis of national agency reports, on-offline press reports, and domestic and foreign robot company press releases. The COVID-19 pandemic has raised interest in medical robots. And there is a need to apply healthcare robots that can perform tasks such as disinfection, logistics transfer, screening tests, monitoring of patients, remote medical treatment support for isolated patients, and video calls with family members. Therefore, it is considered that future correct development and application of healthcare robots and empirical research to verify them should be continued based on sufficient consideration for various problems associated with the practical application of robots.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1808-1810
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• 2004

This paper describes the discharge characteristics of liquid $SF_6$ (-41$[^{\circ}]$, 1.7[atm]) and $LN_2$ for plane to plane, needle to plane, plane to needle and sphere to plane electrode with gap variations from 1[mm] to 12[mm]. From this result, the breakdown voltage was increased with increasing gap length. Especially, the formation of bubbles by evaporation was observed in spite of non-applying voltage source. A corona is created of the applying voltage from the bubbles on the electrodes applied voltage. We consider it equal mechanism of corona as void exists in solid insulator. The results of liquid $SF_6$ and $LN_2$ discharge characteristics were caused by bubble formed evaporation and applied electric field voltage. Corona was happened to weak bubble and was proceed to new bubble breakdown.

• CELLMED
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• v.10 no.4
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• pp.29.1-29.6
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• 2020

COVID-19 (Corona Virus Disease-2019) is an infectious respiratory disease caused by the most recently discovered coronavirus, SARS-CoV-2 (Severe Acute Respiratory Syndrome Corona virus-2). This new viral disease was unknown before the outbreak began in Wuhan, China, in December 2019. As of November 16th 2020, it affects about 54.3 million populations, death troll increased to 1.32 million cases in worldwide. Whereas in India 8.85 cases are infected with COVID-19, of which 1, 30, 112 cases were died. Till now there has been no specific anti-virus drug or vaccines are available for the treatment of this disease, the supportive care and non-specific treatment to the symptoms of the patient are the only options in Biomedicine, the entire world turns its attention towards alternative medicine or Traditional medicine. Siddha medicine is one of the primordial systems of medicine practiced in the southern part of India, it dealt a lot about pandemic, and its management. This review provides an insight into Pandemic in Siddha system and its management in both ancient history and modern history, National and state level Government policies related to current pandemic, World Health Organization (WHO) guidelines on usage of unproven drug during infectious disease outbreak, Preparedness of Siddha system during a pandemic outbreak Challenges and Recommendations.