• Journal of Korean Society of Archives and Records Management
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• v.18 no.4
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• pp.183-204
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• 2018

The main purpose of this study was to investigate the research topics of the Journal of Korean Society of Archives and Records Management, which is one of the main academic journals of archival research in Korea. To achieve this objective, a total of 875 author-assigned Korean keywords were collected from the 390 papers published from the first issue (i.e., 2001) to the current issue (i.e., 2017) in the target journal. The collected keywords were analyzed using NetMiner V.4 to discover their frequency, degree centrality, and betweenness centrality. Results showed that "Archival Information Services," "Electronic Records," "Historical Archives," "Archivists," and "National Archives of Korea" showed the most frequently conducted research topics; whereas "Archival Information Services," "Electronic Records," "Evaluation," "Locality Archives," and "Retrieval System" were the most influencing research topics. On the other hand, "Archival Information Services," "Archivists," "Electronic Records," "Archive," and "Metadata" showed the most widely intervening research topics in this research.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.82-90
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• 2019

The purpose of this study was to analyze trends of domestic research on MOOCs(Massive Open Online Courses) for the last 10 years and provides implications for research on education and learning using MOOC. A total of 70 research papers were selected for the analysis. As a result, the research papers on MOOC in Korea have been increasing from 2012 to 2018. Of the 70 research papers, 31 were clearly indicated research subjects, and most of the research was conducted for university students. Regarding the research type, survey research(27.1%) were the most common. The predictors used in the study of MOOCs are demographic characteristics and perceived usefulness and ease of use for independent variables, satisfaction, perceived usefulness and ease of use for the mediators, usage intention and persistence for dependent variables were frequently used. Further implications were discussed for the study.

• Tribology and Lubricants
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• v.35 no.1
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• pp.16-23
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• 2019

In this study, we aim to analyze the effects of both contact layer properties and surface roughness on contact resistance. The contact has a great influence on performance in terms of electrical conduction and heat transfer. The two biggest factors determining contact resistance are the presence of surface roughness and the surface layer. For this reason we calculated the contact resistance by considering both factors simultaneously. The model of this study to calculate contact resistance is as follows. First, the three representative surface parameters for the GW model are obtained by Nayak's random process. Then, the apparent contact area, real contact area, and contact number of asperities are calculated using the GW model with the surface parameters. The contact resistance of a single surface layer is calculated using Mikic's constriction equation. The total contact resistance is approximated by the parallel connection between the same asperity contact resistances. The results of this study are as follows. The appropriate thickness with reduction effect for contact resistance is determined according to the difference in conductivity between the base layer and surface layer. It was confirmed that the standard deviation of surface roughness has the greatest influence on surface roughness parameters. The results of this study will be useful for selecting the surface material and surface roughness when the design considering the contact resistance is needed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.1
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• pp.70-77
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• 2019

$SiO_x$ nanoparticles were granulated, and their microstructures and effects on electrochemical behaviors were investigated. In spite of the promising electrochemical performance of $SiO_x$, nanoparticles have limitations such as high surface area, low density, and difficulty in handling during slurry processing. Granulation can be one solution. In this study, pelletizing and annealing were conducted to create particles with sizes of several decades of micron. Decrease in surface area directly influences the initial charge and discharge process when granules are applied as anode materials for Li-ion batteries. Lower surface area is key to decreasing the amount of irreversible phase-formation, such as $Li_2Si_2O_5$, $Li_2SiO_3$ and $Li_4SiO_4$, as well as forming the solid electrolyte interface. Additionally, aggregation of nanoparticles is required to obtain further enhancement of the electrochemical behavior due to restrictions that there be no $Li_4SiO_4$-related reaction during the first discharge process.

• The Journal of the Korean dental association
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• v.57 no.10
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• pp.595-604
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• 2019

Each college of dentistry in Korea is examining and reorganizing its own curriculum to prepare students for the practical examination of the National Dental Licensing Examination. Conducting an assessment of students' competency of communication skills with standardized patients is the first attempt for the examination. Yonsei University College of Dentistry carried out the evaluation of communication attitude, communication written exam, and communication skills practice with standardized patients for Third year predoctoral students. The purpose of this study is a) to find out the relationship between the variables measured in communication skills education and b) to make a new basis for the application of communication education and evaluation in dentistry. Based on the results of the study, the following suggestions for the operation of a dental communication curriculum can be drawn: First, the communication classes and the practice with standardized patients should be based on the wide support of the school. In addition, the patient-dentist interaction (PDI) should be practiced in the same way as practically possible by predoctoral students. Moreover, a space is required to allow predoctoral students to practice PDI. Second, the communication score given by the standardized patients was the most influential on the total score of PDI. This indicates that the communication practice with the standardized patients for the practical examination of the National Dental Licensing Examination is a meaningful process in the course of its communication education.

• Tuberculosis and Respiratory Diseases
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• v.82 no.4
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• pp.341-347
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• 2019

Background: Information about the epidemiology of venous thromboembolism (VTE) recurrence in Korea is lacking. The purpose of this study was to investigate VTE cumulative recurrence rates and identify risk factors for VTE recurrence among Korean adults. Methods: A retrospective cohort study was conducted on adult patients (${\geq}18years$) admitted to a university teaching hospital for pulmonary embolism (PE) from 2005 to 2013. The main outcome of interest was a recurrence of VTE. We used Cox proportional hazard regression analyses to calculate the relative risk of VTE recurrence. Results: Five-year cumulative incidence of recurrent VTE events was 21.5% (95% confidence interval [CI], 17.7-25.4) in all cases of PE; 17% after provoked and 27% after unprovoked PE. Multivariate analysis showed that body mass index (BMI) of ${\geq}25$ (hazard ratio [HR], 2.02; 95% CI, 1.17-3.46; p=0.01) and longer anticoagulation therapy duration (HR, 0.90; 95% CI, 0.84-0.96; p<0.01) were independently associated with risk of VTE recurrence. Risk factors not found to be statistically significant at the <0.05 level included history of VTE (HR, 1.81; 95% CI, 0.84-3.88; p=0.12), unprovoked PE (HR, 1.70; 95% CI, 0.89-3.25; p=0.10), symptomatic deep vein thrombosis (HR, 1.62; 95% CI, 0.89-2.94; p=0.10), and female sex (HR, 1.42; 95% CI, 0.78-2.55; p=0.24). We found that age, history of cancer, and other co-morbidities did not significantly affect the risk of VTE recurrence. Conclusion: Recurrence of VTE after PE is high. Patients with BMI ${\geq}25$ or reduced anticoagulation therapy duration have a higher risk of recurrent VTE.

• The Journal of Korean Medicine
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• v.40 no.3
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• pp.99-111
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• 2019

Objectives: The purpose of this study was to assess the effects of moxibustion treatment for Cardiac arrhythmia through a systematic review. Methods: Electronic database including Cochrane library, Pubmed, China National Knowledge Infrastructure, Embase, DBpia, and Korean studies Information Service System were searched by combining the keywords such as "arrhythmias", "cardiac arrhythmias", "心律失常", "moxibustion" and "艾灸". Through the searching, 5 randomized controlled trials(RCTs) were included except animal testing and cellular experiment etc. The quality of each RCTs was assessed using the Cochrane risk of bias tool. Results: We included 5RCTs involving 468 participants. Two RCTs compared moxibustion versus conventional treatment, another RCT compared moxibustion plus acupuncture versus conventional treatment, another RCT compared moxibustion plus herbal medicine verus conventional treatment, the other RCT compared moxibustion plus herbal medicine and ointment versus conventional treatment. These studies were evaluated by the efficacy rate of treatments. Studies measured outcomes in efficacy, heart rate, electrocardiogram and symptoms. Each of 5 trials statistically showed a significant differences in efficacy rate. One study reported about side effects and another study reported about complications. The overall risk of bias was unclear in 5 studies. Conclusions: The evidence suggests that moxibustion treatment may help to reduce cardiac arrhythmia, however, it is limited, low-certainty and we cannot rule out benefits or risks with this treatment. High-quality studies that report adverse effects are needed.

• The Journal of the Korean dental association
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• v.57 no.10
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• pp.579-587
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• 2019

Korea became an aged society as of 2018, and will have plunged into a super-aged society by 2025. For the dental treatment of elderly patients, their general conditions are to be considered to make appropriate treatment plans and strategies, based on advanced knowledge of geriatric dentistry and clinical experience. In this study, the social demand for geriatric dental specialists for the treatment of the elderly of Korea is investigated by looking at their general health conditions, ADL (Activities of Daily Living), and IADL (Instrumental Activities of Daily Living), along with the review of the advanced training programs of geriatric dentistry in other countries.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.526-532
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• 2019

In this study, an in-house $^{152}Eu$ calibration source was produced from a custom epoxy matrix with a density of ${\rho}=1.14g\;cm^{-3}$, which is chemically stable and durable form after its solidification. The homogeneity of $^{152}Eu$ in matrix was obtained better than 98%. For a Marinelli beaker geometry, an efficiency calibration procedure was applied to a n-type, coaxial, 78.5% relative efficient HPGe detector in the energy range of 121.7-1408.0 keV by using in-house $^{152}Eu$ calibration source. Then the measured efficiencies for Marinelli geometry were compared with the results calculated by MEFFTRAN and ANGLE softwares for the validation. Although MEFFTRAN and ANGLE have two different efficiency transfer algorithms to calculate the efficiencies, they usually need to use a reliable and accurate reference efficiency values as input data. Hence, reference efficiency values were obtained experimentally from a multinuclide standard source for the same detector-Marinelli geometry. In the present source characterization, the corrections required for self-absorption and true coincidence summing effects for $^{152}Eu$ gamma-rays were also obtained for a such close counting geometry condition. The experimental results confirmed the validity of efficiency calculations obtained by MEFFTRAN and ANGLE softwares that are calculation tools.

• Safety and Health at Work
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• v.9 no.4
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• pp.408-415
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• 2018

Background: Nursing home resident care is an ongoing topic of public discussion, and there is great interest in improving the quality of resident care. This study investigated the association between nursing home employees' job satisfaction and residents' satisfaction with care and medical outcomes. Methods: Employee and resident satisfaction were measured by questionnaire in 175 skilled nursing facilities in the eastern United States from 2005 to 2009. Facility-level data on residents' pressure ulcers, medically unexplained weight loss, and falls were obtained from the Centers for Medicare and Medicaid Services Long-Term Care Minimum Data Set. The association between employee satisfaction and resident satisfaction was examined with multiple and multilevel linear regression. Associations between employee satisfaction and the rates of pressure ulcers, weight loss, and falls were examined with simple and multilevel Poisson regression. Results: A 1-point increase in overall employee satisfaction was associated with an increase of 17.4 points (scale 0-100) in the satisfaction of residents and family members (p < 0.0001) and a 19% decrease in the incidence of resident falls, weight loss, and pressure ulcers combined (p < 0.0001), after adjusting for staffing ratio and percentage of resident-days paid by Medicaid. Conclusion: Job satisfaction of nursing home employees is associated with lower rates of resident injuries and higher resident satisfaction with care. A supportive work environment may help increase quality of care in the nation's nursing homes.