• Journal of The Korean Astronomical Society
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• v.53 no.1
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• pp.1-7
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• 2020

The recent study of Chae et al. (2017) found a one-to-one correspondence between plasma blobs outflowing along a ray formed after a coronal mass ejection (CME) and small X-ray flares. In the present work, we have examined the spatial configuration and the eruption process of the flares that are associated with the blobs by analyzing EUV images and magnetograms taken by the SDO/AIA and HMI. We found that the main flare and the successive small flares took place in a quadrupolar magnetic configuration characterized by predominant magnetic fields of positive polarity, two minor magnetic fragments of negative polarity, and a curved polarity inversion line between them, which suggests that the formation process of the blobs may be similar to that of the parent CME. We also found that the successive flares resulted in a gradual change of the quadrupolar magnetic configuration, and the relevant migration of flaring kernels. The three-dimensional geometry and the property of the current sheet, that is often supposed to be embedded in an observed post-CME ray, seem to keep changing because of mutual feedback between the successive flares and the temporal change of the magnetic field configuration. Our results suggest that the observed post-CME rays may not reflect the characteristics of the current sheet responsible for the impulsive phase of the flare.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.9
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• pp.733-737
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• 2003

The purpose of this study is to analyze the particle removal characteristics of a commercial air cleaner based on the electrostatic precipitator. The air cleaner consists of a positive corona precharger to precharge particles and a collector to remove the charged particles. The test for particle removal efficiency is conducted with tobacco smoke particles of 1.27${\mu}{\textrm}{m}$ in mass median diameter. The result of one-pass filtration test shows that the filtration efficiency is more than 90% for the particles larger than 2.5 Um, while the efficiency for the particles of 0.5～1.0${\mu}{\textrm}{m}$ in case of 4.18 CMM is 70%. For the test room of 5,800${\times}$3,400${\times}$2,600㎣, the concentration of tobacco smoke particles decreases up to 30% of initial values within 30 minutes due to natural reduction and up to 90% of initial values within 30 minutes with the air cleaner operation.

• Korean Journal of Veterinary Service
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• v.40 no.2
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• pp.143-147
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• 2017

A Korean domestic short hair (1-year-old, male) presented with 2 to 3 weeks of seizures, aggressive behavior, vomiting, anorexia, and lethargy. The frequency of seizure had gradually increased from once a week to once every 3 hours. Physical and neurologic examination, diagnostic screening tests, including complete blood count (CBC), serum chemistry, electrolyte, coagulation test, X-ray, ultrasonography, and urinalysis were performed. Feline Leukemia Virus (FeLV), Feline Immunodeficiency Virus (FIV) and Toxoplasma spp. All tested negative, but the Feline Corona Virus (FCoV) kit revealed a positive result. To determine the exact diagnosis, magnetic resonance imaging (MRI) was performed but yielded no specific findings. The patient was then diagnosed with idiopathic epilepsy and treatment of phenobarbital was initiated. A month's treatment with phenobarbital proved ineffective as symptoms worsened. Zonisamide was then selected as an additional anticonvulsant. After adding zonisamide, symptoms improved, and seizures abated for 15 months. This is the first case report in South Korea describing the use of phenobarbital and zonisamide in the treatment of a cat with idiopathic epilepsy.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.4
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• pp.487-494
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• 1996

Simultaneous effects of $C_2H_4$ injection and heterogeneous chemical reactions on non-thermal plasma process to remove $SO_2$ and NOx from flue gas were investigated in the present experimental study. The present results showed that 40% of the electrical power can be reduced in $C_2H_4$ injection and heterogeneous chemical reaction are simultaneously included in the non-thermal plasma precess. As an effort to apply the non-thermal plasma technique to practical flue gas treatment system, a wire-plate type reactor which has technically similar geometry of industrial electrostatic precipitators is used instead of other types of reactors, such as wire-cylinder, packed-bed and surface discharge which are inappropriate to industrial application. In the present study, the photo pictures of positive streamer corona taken by ICCD camera, voltage and current oscillograms, and design criteria of a wire-plate type reactor are also shown, which are needed for industrial application of the non-thermal plasma process.

• The Korean Journal of Emergency Medical Services
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• v.25 no.1
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• pp.85-103
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• 2021

Purpose: This study measured the mental health levels of 119 paramedics, and identified the association of mental health levels with safety environments, personal protective equipment, and coronavirus risk awareness. Methods: A total of 119 out of 428 from Daegu and Gyeongbuk took part in this study. The statistical analysis methods were the t-test, ANOVA, Pearson's correlation analysis and multiple regression analysis. Results: In a multiple regression analysis, females (β=-.137, p=<.001) showed a higher relevance to negative mental health than males. The moderate satisfied (β=-.088, p=.014) and dissatisfied (β=-.147, p=.006) showed a higher relevance to negative mental health than higher satisfied. Moderate stress perception (β=-.199, p=<.001) and higher stress perception (β=-.414, p=<.001) showed a higher relevance to negative mental health than lower stress perception. Corona-virus risk awareness (β=-.050, p=.045) was related to negative mental health and safety environment (β=.136, p=<.001). Personal protective equipment (β=.147, p=<.001) were related to positive mental health. Conclusion: Conclusively, it is necessary to develop and implement high-quality intervention programs using significantly influencing variables to impact the mental health of 119 paramedics.

• Health Policy and Management
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• v.30 no.4
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• pp.431-432
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• 2020

Coronavirus disease 2019 (COVID-19) has been going on for nearly a year. As of December 1, 2020, more than 60 million confirmed cases and 1.4 million deaths have occurred in 220 countries and territories. There is no effective treatment for COVID-19 so far, and vaccines are being developed. However, the vaccine of COVID-19 can be freed from COVID-19 only if there are positive answers to some questions: "Aren't there any major side effects from the vaccine?"; "Is the vaccine effective for enough time?"; "Does the vaccine sufficiently reduce the mortality rate?"; and "Does the vaccine sufficiently reduce the reproduction number?" The fight against COVID-19 will continue for a long time. Therefore, we need to respond by developing the evidence for control of COVID-19, the emerging infectious disease. Extensive quarantine measures in the early stages of COVID-19 need to be elaborated through developing the evidence. Korea Disease Control and Prevention Agency should establish a database for evidence developing COVID-19 control. In this database, based on more than 3 million tested individuals, epidemiological investigation results, health insurance claims data, and government data such as the Ministry of Public Administration and Security, etc. should be linked. It is necessary to disclose this database to academia, etc. to create the evidences of COVID-19 and manage COVID-19 through these. And through the developed evidences, guidelines for physical health and mental health in the era of Corona 19 should be developed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.478-480
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• 2022

This content was produced to reduce the stress of the elderly in nursing homes whose outside activities are controlled in a real situation that has accelerated the untact society as the corona pandemic situation continues to be maintained, and to provide visual and auditory enjoyment even inside nursing homes. Nursing seniors get help from social workers through content usage scenarios. By using digital visual culture contents, you can feel the stress that has been continuously accumulated with virtual people, relieve stress and have a sense of identity. Through this content, it will be possible to give a positive effect to the lives of the elderly in nursing care.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.436-438
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• 2021

This content is implemented for active seniors who actively accept IT digital content as the current metaverse generation arrives. The elderly living in the nursing home can directly explore various parts of the map through the user scenario, so that they can recall their youth or experience various views, such as a place where they spent their lives in the past or a place where they can experience their jobs. In the current situation where the aftermath of Corona is getting stronger, the elderly living in nursing homes can have a positive effect on psychological stability and prevention of depression by using this content.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.22-27
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• 2016

The Electrostatic Charge Prevention Technology is a core factor that highly influences the yield of Ultra High Resolution Flat Panel Display and high-integrated semiconductor manufacturing processes. The corona or x-ray ionizations are commonly used in order to eliminate static charges during manufacturing processes. To develop such a revolutionary x-ray ionizer that is free of x-ray radiation and has function to control the volume of ion formation simultaneously is a goal of this research and it absolutely overcomes the current risks of x-ray ionization. Under the International Commission on Radiological Protection, it must have a leakage radiation level that should be lower than a recommended level that is $1{\mu}Sv/hour$. In this research, the new generation of x-ray ionizer can easily control both the volume of ion formation and the leakage radiation level at the same time. In the research, the test constraints were set and the descriptions are as below; First, In order not to leak x-ray radiation while testing, the shielding box was fully installed around the test equipment area. Second, Implement the metallic Ring Electrode along a tube window and applied zero to ${\pm}8kV$ with respect to manage the positive and negative ions formation. Lastly, the ion duty ratio was able to be controlled in different test set-ups along with a free x-ray leakage through the metallic Ring Electrode. In the result of experiment, the maximum x-ray radiation leakage was $0.2{\mu}Sv/h$. These outcome is lower than the ICRP 103 recommended value, which is $1{\mu}Sv/h$. When applying voltage to the metallic ring electrode, the positive decay time was 2.18s at the distance of 300 mm and its slope was 0.272. In addition, the negative decay time was 2.1s at the distance of 300 mm and its slope was 0.262. At the distance of 200 mm, the positive decay time was 2.29s and its slope was 0.286. The negative decay time was 2.35s and its slope was 0.293. At the distance of 100 mm, the positive decay time was 2.71s and its slope was 0.338. The negative decay time was 3.07s and its slope was 0.383. According to these research, the observation was shown that these new concept of ionizer is able to minimize the leakage radiation level and to control the positive and negative ion duty ratio while ionization.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.59-68
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• 2022

As real-time live streaming broadcasting and non-face-to-face classes are spreading in the Corona era, it is time to take academic interest in online streaming classes. In particular, it is important to clarify why users use online streaming classes. Therefore, this study proposes social presence, interest, convenience of use, and interactivity as characteristics of online streaming classes, and aims to verify how these characteristics affect learning satisfaction and furthermore, recommendation intention. As a result of conducting a survey on 338 Chinese collegestudents, it was found that interactivity, social presence, and interest had a positive effect on learning satisfaction, but the effect of ease did not appear. On the other hand, it was confirmed that learning satisfaction had a positive effect on the online streaming class recommendation intention.