• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.84.1-84.1
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• 2011

In this study, we intend to inquire of how the temporal variation and spatial distribution of magnetic helicity injection in a CME-producing solar active region are related to the CME occurrence. We therefore investigate long-term (a few days) variation of magnetic helicity injection in the active region NOAA 9236 which produced multiple CME events. As a result, it is found that a noticeable increase in helicity of negative sign was first made for the first ~1.5 days and then 6 CMEs occurred while the relatively more injection of oppositely signed (positive) helicity was taking place for the next ~2 days. Afterwards, 2 CMEs in the region occurred while a more negative helicity is being injected again compared to a positive helicity. In addition, from helicity flux density maps, we found that the CMEs originated from this active region seem to be involved with the interaction of two magnetic field systems characterized by opposite signs of helicity.

• Journal of the Korean Ceramic Society
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• v.53 no.6
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• pp.575-580
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• 2016

Microstructural design of ceramics has generally focused on information gathered at the micro- and macro-scales and related this to how specific properties could be improved. Ceramic processing serves as the key to optimizes the final microstructure. However, the advent of nano-scale microstructures and highly advanced characterization tools are forcing us to develop new knowledge of what is occurring not just at the micro-scale but also at the atomic level. Thus we are now beginning to be able to address how microstructure is influenced by events at the atomic scale using atomic scale images and data. Theoreticians have joined us in interpreting the mechanisms involved in the "microstructural" evolution at multiple scales and how this can be used to enhance specific properties of ceramics. The focus here is on delving into the various layers the "microstructure" in order understand how atomic-scale events influence the structure and properties of ceramics.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4080-4092
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• 2021

In this study, the performance of sequence tracking methods for multiple interaction events in specific CdZnTe Compton imagers was evaluated using Monte Carlo simulations. The Compton imager consisted of a 6 × 6 array of virtual Frisch-grid CZT crystals, where the dimensions of each crystal were 5 × 5 × 12 mm³. The sequence tracking methods for another Compton imager that consists of two identical CZT crystals arrays were also evaluated. When 662 keV radiation was incident on the detectors, the percentages of the correct sequences determined by the simple comparison and deterministic methods for two sequential interactions were identical (~80%), while those evaluated using the minimum squared difference method (55-59%) and Three Compton method (45-55%) for three sequential interactions, differed from each other. The reconstructed images of a 662 keV point source detected using single and double arrays were evaluated based on their angular resolution and signal-to-noise ratio, and the results showed that the double arrays outperformed single arrays.

• Journal of the Korean Home Economics Association
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• v.43 no.8 s.210
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• pp.55-68
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• 2005

The purpose of this study is to examine the effects of negative life events on mental health and to explore possible main and moderating effects of spousal support on mental health with a focus on gender differences. The data for this study were taken from a nationwide random sample of 1,504 married men and women ranging in age from 30 to 59 through structured questionnaires. The data were analyzed using the SPSS WIN program which was used to calculate frequency, mean, 1-test, multiple regressions. The main results were as follows: First, by examining mental health of Korean men and women, women were more likely than men to experience higher levels of depression. Second, there was no gender difference in the sum of experience of negative life events, therefore the date of this study did not support the differential exposure hypothesis. In addition, men perceived more support from their spouses than women. Third, results show that especially the event concerning with job/financial problems has negative impacts on mental health of both men and women, and vulnerability to undesirable life events was not found. Fourth, spousal support is associated with better mental health regardless of gender, and it reduces the harmful effects of life events concerning with job/financial area for both men and women. Also, spousal support reduces the magnitude of the harmful effects of life events concerning with health of men. This study focused on the impact of negative life events and the couple process. It was possible to explore the strength of social support provided from spouse of most importance to the individuals. These results affirm the importance of supportive relationships between couples as a buffer, mitigating harmful effects of negative life events on mental health.

• The Bulletin of The Korean Astronomical Society
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• v.25 no.1
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• pp.26-26
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• 2000

• Journal of Astronomy and Space Sciences
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• v.34 no.3
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• pp.207-212
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• 2017

During the last glacial-interglacial transition, there were multiple intense climatic events such as the Bølling-Allerød warming and Younger Dryas cooling. These events show abrupt and rapid climatic changes. In this study, the climate events and cycles during this interval are examined through wavelet analysis of Arctic and Antarctic ice-core $^{18}O$ and tropical marine $^{14}C$ records. The results show that periods of ~1383-1402, ~1029-1043, ~726-736, ~441-497 and ~202-247 years are dominant in the Arctic region, whereas periods of ~1480, ~765, ~518, ~311, and ~207 years are prominent in the Antarctic TALDICE. In addition, cycles of ~1019, ~515, and ~209 years are distinct in the tropical region. Among these variations, the de Vries cycle of ~202-209 years, correlated with variations in solar activity, was detected globally. In particular, this cycle shows a strong signal in the Antarctic between about 13,000 and 10,500 yr before present (BP). In contrast, the Eddy cycle of ~1019-1043 years was prominent in Greenland and the tropical region, but was not detected in the Antarctic TALDICE records. Instead, these records showed that the Heinrich cycle of ~1480 year was very strong and significant throughout the last glacial-interglacial interval.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.110.1-110.1
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• 2012

We studied the source regions of 12 solar energetic particle (SEP) events seen between 2010 August and 2012 January at STEREO-A, B and ACE, when the two STEREO spacecraft were separated by about $180^{\circ}$. All events were associated with strong flares (C1 - X6) and fast coronal mass ejections (CMEs) accompanied by type II radio bursts. We have determined the arrival times of the SEP events at the three spacecraft. EUV waves observed in $195{\AA}$ and $193{\AA}$ channels of STEREO and SDO/AIA are tracked across the Sun and the arrival time of the EUV wave at the photospheric source of open field lines extending to the spacecraft connection points at 2.5 Rsun estimated. We found 7 events with flux enhancements in all spacecraft and 4 in two spacecraft. Most events came from a single source. The results show that magnetic field connections between source regions and the spacecraft play an important role in abrupt flux enhancements. In the most cases, EUV waves at the Sun are associated with a wide longitudinal spread of the SEPs.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.3
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• pp.107-118
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• 2020

Chloral hydrate is the oldest and most common sedative drug used in moderate sedation for pediatric dental patients. Hence, the purpose of this article is to review the safety and possible adverse events of this drug when used for pediatric dental treatment. A bibliographic search in PubMed, MEDLINE, Cochrane Library and KMbase, KISS, DBpia, KoreaMed, and RISS databases was performed. Using the keywords "dental sedation," "chloral hydrate," and "children or adolescent," 512 scientific articles were found. Subsequently, 183 studies were individually assessed for their suitability for inclusion in this literature review. Altogether, 24 studies were selected. They included 12 cases of death before, during, or after chloral hydrate sedation for dental treatment, majorly due to dosing error and use of multiple sedatives. Additionally, intraoperative adverse events were mostly respiratory problems such as hypoxia and apnea, but most events were temporary. After treatment, prolonged sedation, including excessive sleep and less activity were the most common postoperative adverse events, and even death cases were reported. Despite the wide acceptance of chloral hydrate as a sedative-hypnotic agent, the risk of adverse events and adequate dose should be of great concern when using it for pediatric dental sedation.

• The Journal of Korean Academic Society of Nursing Education
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• v.27 no.4
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• pp.447-455
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• 2021

Purpose: The present study utilizes a descriptive research design to investigate the moderating effect of resilience on the relationship between the experience of traumatic events and turnover intention among intensive care unit (ICU) nurses. Methods: The participants were 161 hospital nurses who voluntarily agreed to participate in this study. Traumatic event experience, turnover intention, and resilience were assessed. The data were analyzed with hierarchical multiple regression using the SPSS 26.0 software program. Results: The experience of traumatic events had a statistically significant positive correlation with turnover intention (r=.17, p=.037), whereas it had a statistically significant negative correlation with turnover intention and resilience (r=-.37, p<.001). Resilience had a moderating effect on the relationship between the experience of traumatic events and turnover intention (𝛽=-.20, p=.007). Conclusion: The results of this study found that the experience of traumatic events among ICU nurses was a significant factor in turnover intention and that resilience moderated the strength of the relationship between such experiences and turnover intention. Therefore, to prevent ICU nurses' experience of a traumatic event from leading to their leaving nursing, it is necessary to formulate preventive measures and interventions for traumatic events, while enhancing resilience among ICU nurses.

• Geophysics and Geophysical Exploration
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• v.16 no.4
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• pp.293-299
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• 2013

The recent Multiple Lapse Time Window (MLTW) analysis of Korean Peninsula event showed that the focal depth was far greater influence factor than the velocity structure of the model, applying the analysis of the direct simulation Monte Carlo (DSMC) method. Thus, using the events with focal depth of about 10 km, this study considered 330 paths connecting 41 events and 71 stations, and re-examined uniform and depth-dependent velocity models previously studied. As a result, the residual of misfit function greatly decrease from analytic model to DSMC model, reflecting variation of the focal depth from 0 to 10 km. On the other hand, the difference of residuals for each velocity model were relatively small.