• Asia-Pacific Journal of Business
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• v.15 no.1
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• pp.209-223
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• 2024

Purpose - This article analyzes the impact of macroeconomic variables of the United States, China, and Korea on KOSPI and VKOSPI, in that United States and China have a great influence on Korea, having an export-driven economy. Design/methodology/approach - The influence of US, China, and Korea interest rates, industrial production index, consumer price index, US employment index, Chinese real estate index, and Korea's foreign exchange reserves on KOSPI and VKOSPI is analyzed on monthly basis from Jan 2012 to Aug 2023, using multifactor model. Findings - The KOSPI showed a positive relationship with the U.S. industrial production index and Korea's foreign exchange reserves, and a negative relationship with the U.S. employment index and Chinese real estate index. The VKOSPI showed a positive relationship with the Chinese consumer price index, and a negative relationship with the U.S. interest rates, and Korean foreign exchange reserves. Next, dividing the analysis into two periods with the Covid crisis and the analysis by country, the impact of US macroeconomic variables on KOSPI was greater than Chinese ones and the impact of Chinese macroeconomic variables on VKOSPI was greater than US ones. The result of the forward predictive failure test confirmed that it was appropriate to divide the period into two periods with economic event, the Covid Crisis. After the Covid crisis, the impact of macroeconomic variables on KOSPI and VKOSPI increased. This reflects the financial market co-movements due to governments' policy coordination and central bank liquidity supply to overcome the crisis in the pandemic situation. Research implications or Originality - This study is meaningful in that it analyzed the effects of macroeconomic variables on KOSPI and VKOSPI simultaneously. In addition, the leverage effect can also be confirmed through the relationship between macroeconomic variables and KOSPI and VKOSPI. This article examined the fundamental changes in the Korean and global financial markets following the shock of Corona by applying this research model before and after Covid crisis.

• Fire Science and Engineering
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• v.33 no.2
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• pp.30-38
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• 2019

Tracking, which is one of the main causes of electrical fires, is perceived as a physical phenomenon of electrical discharge. Hence tracking should be explained based on electric field analysis, conduction path by electron generation, and gas discharge physics. However, few papers have considered these details. This paper proposes a tracking mechanism including their effects on tracking progress. In order to prove this mechanism, a tracking experiment, an electric field analysis for the carbonization evolution model, and an explanation of the tracking process by gas discharge physics were conducted. From the tracking experiment, the current waveforms were measured at each stage of the tracking progress from corona discharge to tracking breakdown. The electric field analysis was carried out in order to determine the electric field on the surface of a dry-band and the high electric field region for electron generation during the generation and progress of carbonization. In this paper, the proposed tracking mechanism consisted of six stages including electron avalanche by corona discharge, accumulation of positive ions, expansion of electron avalanche, secondary electron emission avalanche, streamer, and tracking by conductive path. The pulse current waveforms measured in the tracking experiment can be explained by the proposed tracking mechanism. The results of this study will be used as the technical data to detect tracking phenomenon, which is the cause of electric fire, and to improve the proof tracking index.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.405-419
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• 2022

The purpose of this study is to find out the progress of social welfare field practice at students, universities, and training institutions in Seoul and Gyeonggi Province during the With COVID-19 era, and to suggest effective social welfare field practice operation plans. To this end, a survey was conducted on 181 people who completed social welfare field practice courses, and the final research results are as follows. First, the operation situation of practice institutions in the era of With COVID-19 was the highest when they were conducted together with 'face-to-face, non-face-to-face', and student satisfaction was positive when partial non-face-to-face practice education was conducted. Despite repeated shutdowns due to COVID-19, the degree of participation in face-to-face services was more than 9 times and the number of supervision was more than 6 times, and many responded that the quality of supervision, a social welfare field training institution, was "generally high." Second, as a result of examining the level of practice performance, trainees, and training institutions, there was a significant relationship between training institution factors and practice performance, and third, as a result of examining how the university, trainees, training institution factors, and practice performance. Therefore, in order to derive the results of social welfare field practice in the era of With Corona, programs to promote and strengthen non-face-to-face exchanges at the university level are necessary, and an education system that also provides non-face-to-face practice guidance suitable for the With Corona era. In addition, various support for the practice system of government ministries and related institutions, including universities and practice institutions, is needed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.9
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• pp.745-752
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• 2006

DOS and NaCl aerosol particles were used to determine collection efficiencies of a 2-stage electrostatic wet scrubber with respect to particle size. The DOS and NaCl aerosols have geometric mean diameters of 0.1-3.0 urn, geometric standard deviations of $1.1{\sim}1.8$ and total number concentrations of $450{\sim}2,400\;particles/cm^3$. The tested operating variables for the electrostatic wet scrubber included air velocity and water injection rate. It was shown from the experimental results that particle collection efficiencies increased in the submicron particle size range when different polarities were applied on the water nozzle and corona wire, respectively. This increase in the collection efficiency is attributed to strong electrostatic attraction between the negative water droplets and positive submicron particles. The collection efficiencies also increased when water injection rate was increased or air velocity was decreased. Meanwhile, the pressure drop across the wet scrubber decreased by 90% compared with the existing mechanical wet scrubber. Finally, ammonia gas was used to determine gas removal efficiencies. It was observed that the gas removal efficiencies increased when the air velocity was decreased or the water injection rate was increased.

• Journal of Yeungnam Medical Science
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• v.30 no.2
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• pp.95-100
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• 2013

Background: This study was performed to investigate the epidemiologic and clinical features of acute respiratory viral infection in hospitalized children. Methods: From 2010 to 2012, we tested nasopharyngeal swab specimen in 1,584 hospitalized children with multiple real-time polymerase chain reactions to identify 10 kinds of respiratory viruses (including influenza virus A, B (FluA, FluB), respiratory syncytial virus (RSV), human metapneumovirus (MPV), adenovirus (AdV), human coronavirus (CoronaV), human enterovirus (HEV), human bocavirus (HBoV), parainfluenza virus (PIV), and human rhinovirus (Rhinovirus)). We analyzed the positive rate, annual and seasonal variations, and clinical features (respiratory tract and non-respiratory tract) according to the retrospective review of medical records. Results: Respiratory viruses were detected from 678 (42.8%) of 1,584 patients. The most common detected virus was RSV (35.0%), and then AdV (19.0%), HEV (18.1%). The critical period of the respiratory viral infection was during the first 12 months of a child's life. PIV increased by 8.4%, 12.1%, and 21.1% annually. Bronchiolitis was most frequently caused by RSV, and croup was frequently caused by PIV. The most common cause of meningitis was HEV. Hepatitis-associated respiratory virus was developed 111 in 678 cases. Conclusion: Although this study was confined to a single medical center for three years, we identified the epidemiology and clinical feature of respiratory viruses in Daegu from 2010 to 2012. Future surveillance will be necessary for annual and seasonal variations.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.3
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• pp.229-246
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• 2020

The global environment is rapidly changing due to the Coronavirus outbreak, especially in areas that have been relatively neglected, such as border areas. In particular, In the post-COVID era, the border area between the two Koreas requires a new perception and conceptualization as a space for reconciliation, cooperation and coexistence. Through the status and outlook of post-COVID era, this paper analyzed the promoting directions of each situation, such as SWOT analysis, depending on the characteristics of changes such as domestic preference, changes into standards of new national competitiveness, changes into regional value chains, and the transition to digital economy in the era of the Fourth Industrial Revolution. Based on the previous analysis, this paper proposed realistic approaches such as the utilization of buffer zones, expansion of non-political cooperation to prepare resilience, and promotion of new growth engine industries. In addition, this paper suggested prepared strategies for analyzing the influence of positive and negative cases and responding to them by writing possible scenarios.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.3
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• pp.237-246
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• 1994

Experimental data are reported for charging and collection of NaCl aerosols in the 0.03- to $0.2{\mu}m$-geometric-mean-diameter range in 2-stage parallel-plate electrostatic precipitators. The NaCl aerosols are generated with geometric standard deviation of about 1.74 and particle generation rate of about 10^9 particles/see by the constant output atomizer and injected into the air flow in the clean wind-tunnel. The 2-stage parallel-plate electrostatic precipitator installed in the test section of the wind-tunnel is operated with a positive corona discharge. The NaCl aerosols in the channel flow are sampled and transported to the aerosol particle number concentration measurement system by using the isoaxial sampling and transport system constructed based on the Okazaki and Willeke design. The aerosol particle number concentration measurement system measures the size distribution of submicrometer aerosols by an electrical mobility detection technique. It is confirmed from comparing the measured collection efficiencies in this study and the predicted ones by our previous theoretical analysis that the predicted collection efficiencies agree well with the experimental ones. It is also found from the comparison that below about $0.02{\mu}m$ all particles are not charged and the uncharged particles are not collected, and consequently 2-stage parallel-plate electrostatic precipitators are not suitable for that particle size range.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.245-251
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• 2008

Although many studies have been carried out about binary gas mixtures with $SF_6$, few studies were presented about breakdown characteristics of $SF_6/CF_4$ mixtures. At present study the breakdown characteristics of $SF_6/CF_4$ mixtures in non-uniform field was performed. The experiments were carried out under AC voltage and standard lightning impulse(SLI) voltage. Breakdown characteristics were investigated for $SF_6/CF_4$ mixtures when AC voltages and standard lighting impulse voltage was applied in a needle-plane. The needle-plane electrode whose gap distance was 3 mm were used in a test chamber. $SF_6/CF_4$ mixtures contained from 0 to 100% $SF_6$ and the experimental gas pressure ranged from 0.1 to 0.5 MPa. The breakdown characteristics of $SF_6/CF_4$ mixtures in non-uniform field may be influenced by defects like needle-shaped protrusions. In case of slowly rising SLI voltage and AC voltage it is enhanced by corona-stabilization. This phenomena caused by the ion drift during streamer development and the resulting space-charge is investigated. In non-uniform field under negative SLI voltage the breakdown voltage was increase linearly but under positive SLI voltage the breakdown voltage increase non-linearly. The breakdown voltage in needle-plane electrode displayed N shape characteristics for increasing the content of $SF_6$ at AC voltage. $SF_6/CF_4$ mixture has good dielectric strength and arc-extinguishing properties than pure SF6. This paper presents experimental results on breakdown characteristics for various mixtures of $SF_6/CF_4$ at practical pressures. We could make an environment friendly gas insulation material with maintaining dielectric strength by combing $SF_6\;and\;CF_4$ which generates a lower lever of the global warming effect.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.202-209
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• 2020

Due to Corona 19, non-face-to-face education was conducted at general universities, so it was necessary to conduct non-face-to-face faculty advisor counseling. SNS counseling using photovoices was conducted in the 6th session and FGI for 10, 3rd graders in the early childhood education department of a college in the metropolitan area. The results of the study analyzing students' perceptions of the counseling and content of the counseling are as follows. First, the research participants positively recognized the SNS counseling that applied the photovoice technique. Second, they gradually adapted to non-face-to-face daily life and learning and evaluated the positive aspects, but they complained of fear in career and employment. A non-face-to-face counseling strategy and follow-up studies were proposed through this case study.

• Journal of East-West Nursing Research
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• v.27 no.1
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• pp.14-21
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• 2021

Purpose: This study aims to examine the levels of posttraumatic stress disorder (PTSD), depression and social stigma among nurses caring for Corona Virus Disease-19 (COVID-19) patients. Methods: 169 nurses caring for COVID-19 patients participated in this study. Data collection was conducted at university hospitals from March 1 to August 31, 2020. Data analysis was performed for descriptive statistics, t-test, ANOVA, and Pearson correlation coefficients using SPSS/WIN 24.0 program. Results: The mean scores of PTSD, depression and social stigma were 25.16±16.80, 17.26±8.63 and 5.83±2.84, respectively. The PTSD scores were significantly different between the department (F=2.89, p=.037). Depressive scores were significantly different between the marital status (t=2.27, p=.024) and the department (F=4.91, p=.003). Social stigma scores were significantly different between age (F=6.49, p=.002), marital status (t=-3.30, p=.008), having or not having children (t=3.82, p=.001), department (F=5.82, p=.001) and clinical experience (F=7.43, p=.001). Positive correlations were found between PTSD and depression (r=.70, p<.001) and social stigma (r=.22, p<.004). Conclusion: Integrated assessment and management are required to address the psychological and emotional problems faced by nurses caring for COVID-19 patients, and active follow-up measures should be considered.