• The Journal of Korean Academic Society of Nursing Education
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• v.27 no.2
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• pp.197-209
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• 2021

Purpose: The purpose of this study is to evaluate the validity and reliability of the Korean Bereavement Care Confidence Scale (K-BCCS). Methods: The Perinatal Bereavement Care Confidence Scale (PBCCS) was translated into Korean according to an algorithm of cultural adaptation process and excluded six items which were specific to perinatal bereavement. A total of 229 clinical nurses participated in the study. Construct validity, convergent validity, discriminant validity, and group comparison validity were evaluated, and Cronbach's α was calculated to estimate the reliability of the K-BCCS. Results: The K-BCCS consisted of 31 items in 7 factors, including knowledge and skills for bereavement care (12 items), organizational support (6 items), awareness of the needs (3 items), interpersonal skills (3 items), workload influence (2 items), continuous education (2 items), and understanding the grief process (3 items). The factor loading of 31 items within the 7 factors ranged from .60 to .86. For the convergent validity, the construct reliability (CR) ranged from .74 to .94, and the average variance extracted (AVE) ranged from .49 to .73, which is considered acceptable. The discriminant validity showed that the AVEs of the subscales were greater than the square of the correlation coefficient r. The nurses who had experience providing bereavement care (t=4.94, p<.001) or had received bereavement education (t=6.64, p<.001) showed higher K-BCCS values those without experience. The Cronbach's α of 31 items was .93 and ranged from .60 to .94 per subscale. Conclusion: The K-BCCS is a valid and reliable tool for evaluating nurses' confidence in bereavement care.

• Journal of Korea Trade
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• v.23 no.5
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• pp.87-101
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• 2019

Purpose - This paper examines the effectiveness of the foreign exchange risk insurance system in the promotion of SME exports in Korea. The purpose of this study is to analyze the short-term and long-term responses of SME exports to foreign exchange risk insurance support policies. Based on these empirical studies, we would like to present some operational improvements to the operation of the foreign exchange risk insurance system. Design/methodology - In order to analyze the effect of exchange risk insurance on the exports of SMEs, a VAR model consisting of foreign exchange risk insurance underwriting values, export relative price, and domestic demand pressure, including export volume, was established. The study began with tests of the stationarity of time series data. The unit root tests showed that all concerned variables were non-stationary. Accordingly, the results of the cointegration test showed that the tested variables are not cointegrated. Finally, an impulse response function and variance decomposition analysis were conducted to analyze the impulse of foreign exchange risk insurance on exports of SMEs. Findings - As a result of estimating the VAR (1) model, foreign exchange risk insurance was found to be significant at a 1% significance level for SME' export promotion. In the impulse response analysis, SMEs' export response to the impulse of foreign exchange risk insurance showed that exports gradually increased until the third quarter, and then slowed down. However, the impulse did not disappear, and appeared continuously. Originality/value - This study analyzed the effect of foreign exchange insurance on exports of SMEs by applying the VAR model. In particular, this study is the first to analyze the short-term and long-term effects of foreign exchange risk insurance on exports of SMEs. The empirical evidence in the current study have a policy implication for the policy authority to support and promote the foreign exchange risk insurance in the effect of exchange rate volatility on Korea' export SMEs.

• The Journal of Advanced Prosthodontics
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• v.14 no.6
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• pp.360-368
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• 2022

PURPOSE. This study assessed the physical and mechanical properties of interim crown materials fabricated using various digital techniques after accelerated aging. MATERIALS AND METHODS. Three groups of interim dental restorative materials (N = 20) were tested. The first group (CO) was fabricated using a conventional manual method. The second group (ML) was prepared from prefabricated resin blocks for the milling method and cut into specimen sizes using a cutting disc. The third group (3D) was additively manufactured using a digital light-processing (DLP) 3D printer. Aging acceleration treatments using toothbrushing and thermocycling simulators were applied to half of the specimens corresponding to three years of usage in the oral environment (N = 10). Surface roughness (Ra), Vickers microhardness, 3-point bending, sorption, and solubility tests were performed. A 2-way analysis of variance (ANOVA) and Fisher's multiple comparison test were used to compare the results among the groups. RESULTS. The mean surface roughness (Ra) of the resin after accelerated aging was significantly higher in the CO and ML groups than that before aging, but not in the 3D group. All groups showed reduced hardness after accelerated aging. The flexural strength values were highest in the 3D group, followed by the ML and CO groups after accelerated aging. Accelerated aging significantly reduced water sorption in the ML group. CONCLUSION. According to the tested material and 3D printer type, both 3D-printed and milled interim restoration resins showed higher flexural strength and modulus, and lower surface roughness than those prepared by the conventional method after accelerated aging.

• Computers and Concrete
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• v.30 no.6
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• pp.393-407
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• 2022

Due to the enormous cement content, pozzolanic materials, and the use of different aggregates, sustainable controlled low-strength material (CLSM) has a higher material cost than conventional concrete and sustainable construction issues. However, by selecting appropriate materials and formulations, as well as cement and aggregate content, whitethorn costs can be reduced while having a positive environmental impact. This research explores the desire to optimize plastic properties and 28-day unconfined compressive strength (UCS) of CLSM containing powder content from unprocessed-fly ash (u-FA) and recycled fine aggregate (RFA). The mixtures' input parameters consist of water-to-cementitious material ratio (W/CM), fly ash-to-cementitious materials (FA/CM), and paste volume percentage (PV%), while flowability, bleeding, segregation index, and 28-day UCS were the desired responses. The central composite design (CCD) notion was used to produce twenty CLSM mixes and was experimentally validated using MATLAB by an Artificial Neural Network (ANN). Variance analysis (ANOVA) was used for the determination of statistical models. Results revealed that the plastic properties of CLSM improve with the FA/CM rise when the strength declines for 28 days-with an increase in FA/CM, the diameter of the flowability and bleeding decreased. Meanwhile, the u-FA's rise strengthens the CLSM's segregation resistance and raises its strength over 28 days. Using calcareous powder as a substitute for cement has a detrimental effect on bleeding, and 28-day UCS increases segregation resistance. The response surface method (RSM) can establish high correlations between responses and the constituent materials of sustainable CLSM, and the optimal values of variables can be measured to achieve the desired response properties.

• The Journal of Advanced Prosthodontics
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• v.14 no.4
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• pp.262-272
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• 2022

PURPOSE. This study aimed to analyze the shear bond strength between the 3D-printed denture base and the chairside relining material, according to the surface treatment. MATERIALS AND METHODS. Cylindrical specimens were prepared using DENTCA Denture Base II. The experimental groups were divided into 6 (n = 10): no surface treatment (C), Tokuyama Rebase II Normal adhesive (A), sandblasting (P), sandblasting and adhesive (PA), sandblasting and silane (PS), and the Rocatec system (PPS). After bonding the chairside relining material to the center of the specimens in a cylindrical shape, they were stored in distilled water for 24 hours. Shear bond strength was measured using a universal testing machine, and failure mode was analyzed with a scanning electron microscope. Shear bond strength values were analyzed using one-way analysis of variance, and Tukey's honest significant difference test was used for post-hoc analysis (P < .05). RESULTS. Group PPS exhibited significantly higher shear bond strength than all other groups. Groups P and PA displayed significantly higher bond strengths than the control group. There were no significant differences between groups PS and A compared to the control group. Regarding the failure mode, adhesive failure occurred primarily in groups C and A, and mixed failure mainly in groups P, PA, PS, and PPS. CONCLUSION. The shear bond strength between the 3D-printed denture base and the chairside relining material exhibited significant differences according to the surface treatment methods. It is believed that excellent adhesive strength will be obtained when the Rocatec system is applied to 3D-printed dentures in clinical practice.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.129-136
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• 2022

In this study, we aimed to develop a maturity classification model for tomatoes using hyperspectral imaging in the range of 400 - 1,000 nm. Fifty-seven tomatoes harvested in August and November of 2021 were used as the sample set, and hyperspectral data was extracted from the surfaces of these tomatoes. A combined method of SNV (standard normal variate) and SG (Savitzky-Golay) methods was used for the pre-processing of the hyperspectral data. In addition, the hyperspectral data were analyzed for all maturity stages and considering bandwidths with different FWHM (full width at half maximum) values of 2, 25, and 50 nm. The PCA (principal component analysis) method was used to analyze the principal components related to maturity stages for the tomatoes. As a result, 500 - 550 nm and 650 - 700 nm bands were found to be related to the maturity stages of tomatoes. In addition, PC1 and PC2 explained approximately 97% of the variance at all FWHM conditions and thus were used as input data for classification model training based on the SVM (support vector machine). The SVM models were able to classify tomato maturity into five stages (Green, Turning, Pink, Light red, and Red) with over 95% accuracy regardless of the FWHM condition. Therefore, it was considered that hyperspectral data with 50 nm FWHM and SVM is feasible for use in the classification of tomato maturity into five stages.

• Imaging Science in Dentistry
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• v.52 no.4
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• pp.399-408
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• 2022

Purpose: The purpose of this study was to compare volume measurements obtained using 2 image software packages on Digital Imaging and Communications in Medicine (DICOM) images acquired from 1 multidetector computed tomography and 5 cone-beam computed tomography devices, using different protocols for physical volume measurements. Materials and Methods: Four pieces of bovine leg were prepared. Marrow was removed from 3 pieces, leaving cortical bone exposed. The resulting space of 1 piece was filled with water, another was filled with propylene glycol, and the third was left unfilled. The marrow in the fourth sample was left fully intact. Volume measurements were obtained after importing DICOM images into the Dolphin Imaging 11.95 and ITK-SNAP software programs. Data were analyzed using 3-way analysis of variance with a generalized linear model to determine the effects of voxel size, software, and content on percentage mean volume differences between tomographic protocols. A significance level of 0.05 was used. Results: The intraclass correlation coefficients for intraobserver and interobserver reliability were, respectively, 0.915 and 0.764 for the Dolphin software and 0.894 and 0.766 for the ITK-SNAP software. Three sources of statistically significant variation were identified: the interaction between software and content (P=0.001), the main effect of content (P=0.014), and the main effect of software (P=0.001). Voxel size was not associated with statistically significant differences in volume measurements. Conclusion: Both content and software influenced the accuracy of volume measurements, especially when the content had gray values similar to those of the adjacent tissues.

• The Journal of Korean Physical Therapy
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• v.35 no.3
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• pp.71-76
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• 2023

Purpose: This study investigated effect of the scapular retraction exercise on the subacromial and costoclavicular space using different thera-band intensities. Methods: Thirty-six healthy adults participated in this study, and the subjects were randomly divided into three groups (low, moderate, and high-intensity groups). The exercise was conducted twice a week for three weeks. The subacromial and costoclavicular space were measured before and after the intervention via ultrasonography. Data analysis was performed using the two-way Analysis of Variance with repeated measures and the paired t-test. Results: The effect of the scapular retraction exercise on the subacromial and costoclavicular space using a thera-band after a 60° shoulder abduction has significant difference in all groups (p<0.05). However, there was no significant difference between the groups, and the values in the groups before the exercise did not differ significantly from those after the exercise (p>0.05). Conclusion: Our results indicate that the scapular retraction exercise after a 60° shoulder abduction can be used to widen the subacromial and costoclavicular spaces.

• Restorative Dentistry and Endodontics
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• v.48 no.1
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• pp.2.1-2.12
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• 2023

Objectives: In this study, natural substances were introduced as primary dental pulp caps for use in pulp therapy, and the antimicrobial and cytotoxic properties of these substances were investigated. Materials and Methods: In this in vitro study, the antimicrobial properties of calcium-enriched mixture (CEM) cement, propolis, and propolis individually combined with the extracts of several medicinal plants were investigated against Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Then, the cytotoxicity of each substance or mixture against pulp stem cells extracted from 30 primary healthy teeth was evaluated at 4 concentrations. Data were gathered via observation, and optical density values were obtained using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) test and recorded. SPSS software version 23 was used to analyze the data. Data were evaluated using 2-way analysis of variance and the Tukey test. Results: Regarding antimicrobial properties, thyme alone and thyme + propolis had the lowest minimum inhibitory concentrations (MICs) against the growth of S. aureus, E. coli, and P. aeruginosa bacteria. For E. faecalis, thyme + propolis had the lowest MIC, followed by thyme alone. At 24 and 72 hours, thyme + propolis, CEM cement, and propolis had the greatest bioviability in the primary dental pulp stem cells, and lavender + propolis had the lowest bioviability. Conclusions: Of the studied materials, thyme + propolis showed the best results in the measures of practical performance as a dental pulp cap.

• Health Policy and Management
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• v.33 no.1
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• pp.40-54
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• 2023

Background: Based on the increase in the needs for convalescent rehabilitation medical services in Korea, this study aims to calculate the needs for rehabilitation services and examine its determinants for 229 regions. Methods: Claim data from the Health Insurance Review and Assessment Service were used to estimate patients who need to receive rehabilitation services, and data from various sources were also used for analysis. The number of cases and incidence rates of hospitalization related to convalescent rehabilitation were calculated to estimate the needs for services by region, and the results were visualized via a map. Multivariate regression and fixed effects regression using panel data were performed to identify the determinants of regional variation of the incidence rate. Results: First, the incidence rate of rural areas such as Jeolla-do, Gyeongsang-do, and Chungcheong-do was higher than urban areas (metropolitan cities). Second, the population, proportion of the elder, medical aid recipients, financial independence, traffic deaths, smoking, diabetes rate, and medical infrastructure correlated significantly with the incidence rate. Third, 'rho' values which mean the fraction of variance due to individual terms in panel data regression models were 0.965 and 0.976, respectively. Conclusion: The incidence rate of hospitalizations was correlated with most independent variables in this study and there is a gap between urban and rural areas. These regional disparities are fixed in our society. An improved regional convalescent rehabilitation system is suggested to cover the entire area including rural areas with a high rate of aging.