• Landscaping Tree
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• v.19 no.3_4
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• pp.19-19
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• 1994

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.1
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• pp.21-27
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• 2018

Synthesis of ferromagnetic composite materials for the $Cu-BaFe_{12}O_{19}$ system by mechanical alloying (MA) has been investigated at room temperature. A mixture of copper and barium ferrite with a weight ratio of $Cu:BaFe_{12}O_{19}=4:1$, 3 : 2, 2 : 3 and 1 : 4 was used. It is found that $Cu-BaFe_{12}O_{19}$ composite powders in which $BaFe_{12}O_{19}$ is dispersed in copper matrix are successfully produced by mechanical alloying of $BaFe_{12}O_{19}$ with Cu for 80 min. in all composition. The change in X-ray diffraction patterns and magnetic properties reflects the details for the formation of ferromagnetic metal matrix composite of pure Cu and $BaFe_{12}O_{19}$ during mechanical alloying. Magnetization of $Cu-BaFe_{12}O_{19}$ composite powders gradually increases with increasing the amounts of barium ferrite, whereas coercive force of MA powders gradually decreases due to the refinement of barium ferrite powders with ball milling. However, it can be seen that the coercivity of $Cu-BaFe_{12}O_{19}$ MA composite powders with a weight ratio of $Cu:BaFe_{12}O_{19}=4:1$ and 3 : 2 ball-milled for 80 min. is still high value of 1400 Oe and 1450 Oe, respectively suggesting that the refinement of barium ferrite powders during ball milling process tend to be suppressed due to the ductile copper.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.811-816
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• 2011

In this paper, we propose a optimal design using the Evolution Strategy of a high gain $4\times4$ array antenna that have the resonant frequency of a 19.05GHz with 18.86GHz~19.26GHz bandwidth. The proposed array antenna structure is designed to be allocated equally electric power by microstrip patch power splitter. Thus the optimal array antenna with power splitter are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The simulation result of $4\times4$ array antenna is confirmed that the Gain is 19.36 dBi at resonance frequency 19.05GHz.

• Journal of Korean Academy of Nursing
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• v.52 no.3
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• pp.291-307
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• 2022

Purpose: The aims of study were to identify the main keywords, the network structure, and the main topics of press articles related to nurses that have appeared in media reports. Methods: Data were media articles related to the topic "nurse" reported in 16 central media within a one-year period spanning July 1, 2019 to June 30, 2020. Data were collected from the Big Kinds database. A total of 7,800 articles were searched, and 1,038 were used for the final analysis. Text network analysis and topic modeling were performed using NetMiner 4.4. Results: The number of media reports related to nurses increased by 3.86 times after the novel coronavirus (COVID-19) outbreak compared to prior. Pre- and post-COVID-19 network characteristics were density 0.002, 0.001; average degree 4.63, 4.92; and average distance 4.25, 4.01, respectively. Four topics were derived before and after the COVID-19 outbreak, respectively. Pre-COVID-19 example topics are "a nurse who committed suicide because she could not withstand the Taewoom at work" and "a nurse as a perpetrator of a newborn abuse case," while post-COVID-19 examples are "a nurse as a victim of COVID-19," "a nurse working with the support of the people," and "a nurse as a top contributor and a warrior to protect from COVID-19." Conclusion: Topic modeling shows that topics become more positive after the COVID-19 outbreak. Individual nurses and nursing organizations should continuously monitor and conduct further research on nurses' image.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.4
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• pp.495-508
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• 2019

Tidal datums are key and basic information used in fields of navigation, coastal structures' design, maritime boundary delimitation and inundation warning. In Korea, the Approximate Lowest Low Water (ALLW) and the Approximate Highest High Water (AHHW) have been used as levels of tidal datums for depth, coastline and vertical clearances in hydrography and coastal engineering fields. However, recently the major maritime countries including USA, Australia and UK have adopted the Lowest Astronomical Tide (LAT) and the Highest Astronomical Tide (HAT) as the tidal datums. In this study, 1-hr interval 19-year sea level records (1999-2017) observed at 9 tidal observation stations along the west and south coasts of Korea were used to calculate LAT and HAT for each station using 1-minute interval 19-year tidal prediction data yielded through three tidal harmonic methods: 19 year vector average of tidal harmonic constants (Vector Average Method, VA), tidal harmonic analysis on 19 years of continuous data (19-year Method, 19Y) and tidal harmonic analysis on one year of data (1-year Method, 1Y). The calculated LAT and HAT values were quantitatively compared with the ALLW and AHHW values, respectively. The main causes of the difference between them were explored. In this study, we used the UTide, which is capable of conducting 19-year record tidal harmonic analysis and 19 year tidal prediction. Application of the three harmonic methods showed that there were relatively small differences (mostly less than ±1 cm) of the values of LAT and HAT calculated from the VA and 19Y methods, revealing that each method can be mutually and effectively used. In contrast, the standard deviations between LATs and HATs calculated from the 1Y and 19Y methods were 3~7 cm. The LAT (HAT) differences between the 1Y and 19Y methods range from -16.4 to 10.7 cm (-8.2 to 14.3 cm), which are relatively large compared to the LAT and HAT differences between the VA and 19Y methods. The LAT (HAT) values are, on average, 33.6 (46.2) cm lower (higher) than those of ALLW (AHHW) along the west and south coast of Korea. It was found that the S_a and N₂ tides significantly contribute to these differences. In the shallow water constituents dominated area, the M₄ and MS₄ tides also remarkably contribute to them. Differences between the LAT and the ALLW are larger than those between the HAT and the AHHW. The asymmetry occurs because the LAT and HAT are calculated from the amplitudes and phase-lags of 67 harmonic constituents whereas the ALLW and AHHW are based only on the amplitudes of the 4 major harmonic constituents.

• Bulletin of the Korean Chemical Society
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• v.19 no.4
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• pp.414-416
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• 1998

• Biomedical Science Letters
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• v.24 no.4
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• pp.390-397
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• 2018

For the specific detection of human Parvovirus B19 (HuPaV-B19), we designed ten specific PCR primers from 3,800~4,500 nucleotides of HuPaV-B19 complete genome (NC_000883.2). Seventeen candidate PCR primer sets for specific detecting HuPaV-B19 were constructed. In specific reaction of HuPaV-B19, seventeen PCR primer sets showed specific band, however five PCR primer sets were selected basis of band intensity, amplicon size and location. In non-specific reaction with seven reference viruses, four PCR primer sets showed non-specific band, however one PCR primer set is not. Detection sensitivity of final selective PCR primer set was $100fg/{\mu}L$ for 112 minute, and PCR amplicon is 539 base pairs (bp). In addition, nested PCR primer set was developed, for detection HuPaV-B19 from a low concentration of contaminated samples. Selection of nested PCR primer set was basis of sensitivity and groundwater sample tests. Detection sensitivity of final selective PCR and nested PCR primer sets for the detection of HuPaV-B19 were $100fg/{\mu}L$ and $100ag/{\mu}L$ basis of HuPaV-B19 plasmid, it was able to rapid and highly sensitive detection of HuPaV-B19 than previous reports. We expect developed PCR primer set in this study will used for detection of HuPaV-B19 in various samples.

• Journal of Sasang Constitutional Medicine
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• v.33 no.4
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• pp.32-42
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• 2021

Objectives The purpose of this case study was to report a patient with Post COVID-19 syndrome treated with Seunggeumjowi-tang based on Sasang Constitutional Medicine. Methods The patient was hospitalized after being diagnosed with COVID-19 and was suffering with post from COVID-19 syndrome such as fatigue and loss of appetite after discharge. The patient was diagnosed as Taeeumin and treated with Seunggeumjowi-tang. The progress was evaluated with the global assessment scale (GAS). Results and Conclusions Fatigue and anorexia were significantly improved, and other symptoms were restored as before. This case shows the possibility of Sasang Constitutional medication treatment for the sequelae of COVID-19.

• Journal of the Korean Applied Science and Technology
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• v.40 no.3
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• pp.462-475
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• 2023

This study is descriptive research to identify the effect of COVID-19 stress on premenstrual syndrome in female college students and the mediating effect of depression and coping with premenstrual syndrome. The data were collected through an on-line survey for 20 days from November 11 to November 30, 2021, targeting female college students attending C College located in S city. As a result of analyzing a total of 161 data, COVID-19 stress was positively correlated with premenstrual syndrome(r=.383, p<.001) and depression(r=.436, p<.001), and coping with premenstrual syndrome had a positive correlation only in premenstrual syndrome(r=.190, p=.016). As a result of verifying the mediating effect of depression and coping with premenstrual syndrome between COVID-19 stress and premenstrual syndrome, COVID-19 stress had a significant direct effect on premenstrual syndrome(β=4.907, p=.002), and depression(β=6.780, p<.001), and depression had a significant direct effect on premenstrual syndrome(β=.383, p=<.001), coping with premenstrual syndrome had a direct effect on premenstrual syndrome(β=4.292, p=.030) respectively. The indirect effect of verifying the mediating effect in the relationship between COVID-19 stress and premenstrual syndrome confirmed that there was a statistically significant effect only in the path via depression(95% CI, 1.282 to 4.140). Therefore, it is necessary to develop an intervention strategy to reduce depression and alleviate premenstrual syndrome symptoms by controlling related stress, such as COVID-19 stress, in preparation for the outbreak of new infectious diseases and pandemic situations such as COVID-19.