• Journal of Periodontal and Implant Science
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• v.41 no.3
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• pp.143-148
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• 2011

Purpose: Few epidemiologic studies have investigated aggressive periodontitis in Koreans, but such studies of disease prevalence and other clinical characteristics would be invaluable in providing proper treatment. The aim of this study was to assess the prevalence of aggressive periodontitis and to measure the extent of associated periodontal breakdown. Methods: The study population consisted of 1,692 patients who visited the Department of Periodontology, Wonkwang Daejeon Dental Hospital from January to December, 2010. Clinical parameters (probing depth, gingival recession, periodontal attachment loss) were measured by a single examiner, and radiographic examination was performed at the baseline. Results: Twenty-eight (1.65%) patients showed clinical features of aggressive periodontitis, of which 27 patients exhibited the generalized form, and 1 exhibited the localized form. There was no significant difference between the percentage of male and female patients. The probing pocket depth of the maxillary first molar was deeper than that of the other teeth and gingival recession was also the most serious at the maxillary first molar. The periodontal attachment loss was the highest at the maxillary first molar. The average number of missing teeth was 1.29 per subject. Loss of the second molar was prominent. Conclusions: Within the limitations of this study, the periodontal breakdown evaluated by attachment loss was found to be most severe at the first molars of aggressive periodontitis patients. However, further large scale multicenter studies are necessary to access more precise data, including prevalence.

• Journal of Power Electronics
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• v.16 no.3
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• pp.1056-1066
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• 2016

Wireless power transfer (WPT) technology is now recognized as an efficient means of transferring power without physical contact. However, frequency detuning will greatly reduce the transmission power and efficiency of a WPT system. To overcome the difficulties associated with the traditional frequency-tracking methods, this paper proposes a Direct Phase Control (DPC) approach, based on the Second-Order Generalized Integrator Phase-Locked Loop (SOGI-PLL), to provide accurate frequency-tracking for WPT systems. The DPC determines the phase difference between the output voltage and current of the inverter in WPT systems, and the SOGI-PLL provides the phase of the resonant current for dynamically adjusting the output voltage frequency of the inverter. Further, the stability of this control method is analyzed using the linear system theory. The performance of the proposed frequency-tracking method is investigated under various operating conditions. Simulation and experimental results convincingly demonstrate that the proposed technique will track the quasi-resonant frequency automatically, and that the ZVS operation can be achieved.

• The Journal of Korean Academic Society of Nursing Education
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• v.21 no.3
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• pp.350-360
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• 2015

Purpose: The purpose of this study was to evaluate the effectiveness and retention period of immediate remediation for infant cardiopulmonary resuscitation (CPR) in child care teachers. Methods: This study used a nonequivalent comparison pre- and post-test design to measure knowledge about and confidence in infant CPR and an interrupted time-series design to determine skill performance. The experimental group (n=25) received both immediate remediation and video learning for infant CPR, and the comparison group (n=28) received video learning only. Knowledge and confidence were measured before and after 4 weeks. Their skill performance was tested immediately, and 4 weeks, 8 weeks, 12 weeks, and 24 weeks after intervention. Data analysis consisted of ${\chi}^2$ tests, t-tests, paired t-tests, and a generalized linear mixed model. Results: There were significant increases in knowledge and confidence within the experimental group. Skill performance showed a significant difference according to the group factor (F=10.81, p=.002) and measurement time (F=146.80, p<.001). The experimental group maintained significantly higher skill performance than did the comparison group. Conclusion: These findings support the necessity of immediate remediation education for infant CPR to maintain skill performance. In addition, appropriate renewal time and the improvement of training programs for child care teachers are necessary.

• Structural Engineering and Mechanics
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• v.42 no.4
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• pp.571-587
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• 2012

This paper presents results of a numerical analysis performed on a corrugated steel plate (CSP) bridge during a backfilling process. The analysed bridge structure was a box culvert having a span of 12315 mm as well as a clear height of 3550 mm. Obtained calculation results were compared with the experimental ones. The paper is presented with the application of the Fast Lagrangian Analysis of Continua (FLAC) program based on the finite differences method (FDM) to determine behaviour of the soil-steel bridge structure during backfilling. The assumptions of a computational 2D model of soil-steel structure with a non-linear interface layer are described. Parametric analysis of the interface element is also given in order to receive the most realistic calculation results. The method based on this computational model may be used with large success to design calculations of this specific type of structure instead of the conventional and fairly inaccurate analytical methods. The conclusions drawn from such analysis can be helpful mostly for the assessment of the behaviour of steel-soil bridge structures under loads of backfilling. In consideration of an even more frequent application of this type of structure, conclusions from the conducted analysis can be generalized to a whole class of similar structural bridge solutions.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.859-870
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• 2018

Dried red peppers are a staple agricultural product used in Korean cuisine and as such, are an important aspect of agricultural producers' income. Correctly forecasting both their supply and demand situations and price is very important in terms of the producers' income and consumer price stability. The primary objective of this study was to compare the performance of time series forecasting models for dried red peppers in Korea. In this study, three models (an autoregressive model with exogenous variables [ARX], AR-exponential generalized autoregressive conditional heteroscedasticity [EGARCH], and ARX-EGARCH) are presented for forecasting the wholesale price of dried red peppers. As a result of the analysis, it was shown that the ARX model and ARX-EGARCH model, each of which adopt both the rolling window and the adding approach and use the agricultural cooperatives price as the exogenous variable, showed a better forecasting performance compared to the autoregressive model (AR)-EGARCH model. Based on the estimation methods and results, there was no significant difference in the accuracy of the estimation between the rolling window and adding approach. In the case of dried red peppers, there is limitation in building the price forecasting models with a market-structured approach. In this regard, estimating a forecasting model using only price data and identifying the forecast performance can be expected to complement the current pricing forecast model which relies on market shipments.

• Journal of Acupuncture & Meridian Studies
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• v.11 no.6
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• pp.355-360
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• 2018

Introductions: Pneumothorax is the most frequent severe acupuncture-related adverse event occurring at the GB 21 acupoint. This study used ultrasonography (US) to measure the depth of the GB 21 acupoint in adults and assessed its applicability for ensuring safe acupuncture practices. Materials and methods: A US probe was used to measure the vertical depth from the skin to the pleural line of the apex of the lungs at the right and left GB 21 acupoints. The sex, age, body weight, height, and body mass index of each person were recorded. Student t test and generalized estimating equations were used for statistical analysis. Results: Sixty women and 41 men with a median age of 29 years were included in this study. The depth of GB 21 increased with body weight, height, and body mass index (p < 0.001). The mean depth of GB 21 in men (17.4 mm) was greater than that in women (14.6 mm; p < 0.001). The depth difference between the right and left shoulders was significant in men (p < 0.001) but not in women. Conclusions: US can be used to measure GB 21 acupoint depth. Further control studies on its use to ensure safe clinical practices, including preventing acupuncture-related pneumothorax, are warranted.

• Journal of Korean society of Dental Hygiene
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• v.20 no.6
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• pp.973-980
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• 2020

Objectives: This study was to analyz the effects of comparative evaluation of the effects of oil pulling on periodontal indices. Methods: A total subjects were 38; control group (19 subjects) and experimental group (19 subjects). In the experimental group, coconut oil was provided and rinsed the mouth for about 10 minutes once a day. We evaluated possession rate of pocket depth (≥4 mm), possession rate of bleeding on exploring and possession rate of gingival recession (≥1 mm). Results: The possession rate of pocket depth (≥4 mm), bleeding on exploring and gingival recession (≥1 mm) significant difference in interaction between the group and measurement time. Conclusions: The findings of this study indicate that dental hygiene process and oil pulling specialists in care of periodontal diseases were effective mediation.

• Child Health Nursing Research
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• v.28 no.2
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• pp.132-141
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• 2022

Purpose: This study examined the effects of an educational program for fathers on improving father-infant interactions, child-rearing knowledge, and attachment. Methods: In this quasi-experimental study, the participants were recruited by convenience sampling among fathers with infants (2-6 months of age) residing in three districts of Seoul. Fifteen participants in the experimental group and 17 participants in the control group completed the follow-up investigation. A 5-week online and offline intervention program with five sessions was provided to the experimental group. The data were analyzed using generalized estimating equations (GEEs). Results: There was a significant difference in the change in father-infant interaction scores of the experimental group, especially in the caregiver aspect with a significance level of .100 in time and group-to-group interactions (B=6.46, p=.051, 95% confidence interval [CI]=-0.02-12.94). The changes between the groups and times were not statistically significant when it came to infant development knowledge and father-infant attachment. Conclusion: We conclude that hybrid online and offline education should be implemented as an effective method to improve fathers' interactions with their children based on accurate knowledge about infant development.

• The Journal of Korean Medicine
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• v.43 no.1
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• pp.60-72
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• 2022

Objectives: This study aimed to analyze the Korean medical utilization and Korean medical expenses by characteristics of multicultural family members to investigate whether it affects Korean medical utilization. Methods: This study utilized The Korea Health Panel data in 2018, with 238 final participants. We performed a t-test and ANOVA on the difference between Korean medical utilization and Korean medical expenses according to Anderson's Model of Health Service Utilization variables. Logistic regression analysis and generalized linear model analysis were conducted to analyze Korean medical utilization factors. Results: The Korean Medical utilization was 12.61% among the multicultural family members. As a result of regression analysis, the female had high Korean medical utilization(p=.008), and rural area residents had low utilization(p=.017). Korean medical expenses were high when they were female or married. Including the utilization of western medical services by outpatients, Korean medical expenses were high when they were female or outpatients who received western medical services. Conclusions: As a result of this study, the factors influencing Korean medical utilization were gender and residence area. There were differences in Korean medical expenses depending on western medical services use or gender. Therefore, it is necessary to use these factors to expand the Korean Medical utilization by multicultural family members, and research of the Korean medical utilization by disease is needed.

• Journal of Creative Information Culture
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• v.5 no.2
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• pp.145-156
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• 2019

In this study, we have developed and evaluated an information extracting module based on the named entity recognition technique. For the given purpose in this paper, the module was designed to apply to the problem dealing with extraction of postal address information from arbitrary documents without any prior knowledge on the document layout. From the perspective of information technique practice, our approach can be said as a probabilistic n-gram (bi- or tri-gram) method which is a generalized technique compared with a uni-gram based keyword matching. It is the main difference between our approach and the conventional methods adopted in natural language processing that applying sentence detection, tokenization, and POS tagging recursively rather than applying the models sequentially. The test results with approximately two thousands documents are presented at this paper.