• Journal of Korean Society for Quality Management
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• v.52 no.2
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• pp.241-254
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• 2024

Purpose: This paper investigated the effects of issue leadership on employees' work performance. It also explored the mediating role of job challenge in the above relationship. We also tested the moderating effect of psychological ownership in the relationship between issue leadership and job challenge. Finally, this paper examined the moderated mediation effect of psychological ownership in the course of affecting issue leadership on work performance via job challenge. Methods: This paper used a cross-sectional design with questionnaires administered to 390 employees working in Korean firms. It applied an hierarchical and multi-regression analysis by using SPSS 22.0 and Hayes' Macro Process to test the proposed hypotheses including a moderated mediation model. Results: As a result of the analysis, first, it was found that the issue leadership had a positive effect on the work performance. Second, it was also found that issue leadership had a positive effect on the job challenge. In addition, job challenge was found to positive mediating effect in the relationship between issue leadership and work performance. Third, we found that the psychological ownership positively moderated the relationship between issue leadership and job challenge. Finally, the moderated mediating effect was found by confirming that the higher the degree of psychological ownership, the stronger the effect of issue leadership on the work performance via job challenge. Conclusion: This paper contributes to the leadership and work performance studies by identifying the role of issue leadership enhancing employee work performance while confirming connection mechanism and boundary conditions strengthening the positive effect of issue leadership on employee work performance.

• Membrane and Water Treatment
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• v.15 no.2
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• pp.79-88
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• 2024

Modification of Polyvinylidene fluoride (PVDF) hollow fiber membranes (HFMs) characteristics and performance were investigated via post treatment using different oxidants. sodium hypochlorite (NaOCl), hydrogen peroxide (H₂O₂) and potassium persulfate (KPS). Fourier transform infrared (FTIR) and Proton nuclear magnetic resonance (¹H-NMR) results revealed no structural differences after post treatment. Cross-sectional micrographs show finger-like structures at the outer and inner walls of the HFMs and sponge-like structures in middle, where NaOCl and KPS post treated fibers exhibited a decrease in finger-like structures in addition to aggregates appearing on the surface, consequently leading to an increase in the surface roughness (Ra) from 48 nm to 52.8nm and 56 nm, respectively. Hydrogen peroxide post treatment only was observed to decrease the water contact angle from 98° to 81.4°. It was also observed that the elongation at break and the modulus deceased after NaOCl post treatment from 34.5 to 28.5% and from 19.3 Mpa to 16.6 Mpa, respectively. Moreover, pure water flux after H₂O₂ post treatment increased from 87.8 LMH/bar to 113 LMH/bar at 0.45 bar, while no changes were detected for the methylene blue dye rejection (74%) between raw and hydrogen peroxide post treated fibers at the same pressure. According to the findings hydrogen peroxide post treated PVDF HFMs have the most uniform surfaces, with almost no alterations in structural and mechanical properties or porosities with enhanced hydrophilicity and pure water flux maintaining appropriate rejection. Therefore, it is considered an efficient surface modifying agent for UF/NF membranes or low-pressure separators.

• Journal of Cardiovascular Imaging
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• v.30 no.2
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• pp.125-134
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• 2022

BACKGROUND: To assess the interventricular septum (IVS) volume of fetuses from pre-gestational diabetes mellitus (DM) pregnant women by 3-dimensional ultrasound using spatiotemporal image correlation (STIC) and virtual organ computer-aided analysis (VOCAL) methods. METHODS: This was a prospective cross-sectional study of 45 fetuses from pre-gestational DM and 45 fetuses from healthy pregnant women (controls). Only singleton pregnancies between 20 and 34 + 6 weeks of gestation were included. The fetal IVS volumes were obtained off-line using STIC and VOCAL methods. To analyze differences among variables, the Student's t-test and Mann-Whitney U test were used. The correlation among continuous variables was determine using Spearman's correlation test (r). RESULTS: The median of fetal IVS volume was significantly higher in pre-gestational DM than in healthy pregnant women (0.3 cm³ vs. 0.2 cm³, p = 0.032). A strong positive correlation was observed between fetal IVS volume and gestational age at the time of ultrasound examination (r = 0.75, R² = 0.48, p < 0.0001) and between fetal IVS volume and estimated fetal weight (r = 0.63, R² = 0.37, p < 0.0001). No significant correlation was noted between fetal IVS volume and glycated hemoglobin levels (r = -0.16, R² = 0.01, p = 0.540) in the pre-gestational DM pregnant women. CONCLUSIONS: Significant differences were observed in fetal IVS volumes between pre-gestational and healthy mothers, with higher values in the fetuses of pre-gestational DM pregnant women.

• Journal of Cardiovascular Imaging
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• v.30 no.1
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• pp.62-75
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• 2022

BACKGROUND: Due to its location very close to the bundle of His, mitral annulus calcification (MAC) might be associated with the development of atrioventricular (AV) conduction disturbances. This study assessed the association between MAC and AV conduction disturbances identified by cardiac implantable electronic device (CIED) use and electrocardiographic parameters. The association between MAC and traditional cardiovascular risk factors was also assessed. METHODS: This cross-sectional study analyzed 14,771 participants, predominantly men aged 60-75 years, from the population-based Danish Cardiovascular Screening trial. Traditional cardiovascular risk factors were obtained. Using cardiac non-contrast computed tomography imaging, MAC scores were measured using the Agatston method and divided into absent versus present and score categories. CIED implantation data were obtained from the Danish Pacemaker and Implantable Cardioverter Defibrillator Register. A 12-lead electrocardiogram was available for 2,107 participants. Associations between MAC scores and AV conduction disturbances were assessed using multivariate regression analyses. RESULTS: MAC was present in 22.4% of the study subjects. Participants with pacemakers for an AV conduction disturbance had significantly higher MAC scores (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.01-1.23) than participants without a CIED, whereas participants with a CIED for other reasons did not. Prolonged QRS-interval was significantly associated with the presence of MAC (OR, 1.45; 95% CI, 1.04-2.04), whereas prolonged PQ-interval was not. Female sex and most traditional cardiovascular risk factors were significantly associated with high MAC scores. CONCLUSIONS: MAC was associated with AV conduction disturbances, which could improve our understanding of the development of AV conduction disturbances.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.6
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• pp.95-104
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• 2006

The presence of cavitations under pavements or behind tunnel linings of concrete is likely to result in collapse. One method of detecting such voids by non-destructive means is low frequency type radar(GPR). By the way, the size and thickness of small cavitation can't be detected by the present radar technology with low frequency and low resolution when it apply to civil structures like that. To overcome these problems and limitations, this study aims to develope and propose a new analysis method for estimating the depth, cross-sectional size and thickness of cavitations using low frequency radar. A new proposed method is based on the experiments that are carried out for analyzing the correlation between the measurement values(the amplitudes of radar return) of low frequency radar and various type of cavitations. In this process, the threshold value for radar image processing which aims to represent only cavitations to be fitted size can be obtained. As the results, it is clarified that a proposed method has a possibility of estimating cavitation depth, size and thickness with good accuracy in laboratory scale.

• Tuberculosis and Respiratory Diseases
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• v.87 no.4
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• pp.514-523
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• 2024

Background: The government of Korea implemented a strategy of prevention and early diagnosis in high-risk groups to reduce the tuberculosis (TB) burden. This study aims to investigate the TB epidemiology and gap in understanding of TB prevalence among homeless individuals by analyzing active TB chest X-ray (CXR) screening results in Korea. Methods: The Korean National Tuberculosis Association conducted active TB screening with CXR for homeless groups from January 1 to December 31, 2021. Sputum acid-fast bacilli smear and culture were performed for the subjects suggestive of TB on CXR. We performed a cross-sectional analysis of the data in comparison with the national health screening results from the general population. Results: Among 17,713 homeless persons, 40 (0.23%), 3,077 (17.37%), and 79 (0.45%) were categorized as suggested TB, inactive TB, and observation required, respectively. Prevalence of suggested TB in the homeless was significantly higher (3-5 fold) than in the national general health screening based on age category (p<0.005). Twenty-nine cases were confirmed as TB, yielding a prevalence of 164 cases per 100,000 individuals; 19 of these 29 cases showed inactive TB on CXR. Body mass index (p=0.0478) and CXR result (p<0.001) significantly correlated with confirmed TB based on multivariable analysis. Conclusion: Nutrition status and CXR results, especially that of inactive TB, should be considered in active TB screening of the homeless population, where TB prevalence is higher than the general population.

• Physical Therapy Rehabilitation Science
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• v.13 no.3
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• pp.368-373
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• 2024

Objective: This study investigates the influence of femoral and knee torsion angles on toe in-out orientation in adults. Design: Cross-sectional study design. Methods: We measured the passive internal and external rotation range of motion (ROM) of the hip and knee joints in 21 participants using a goniometer. Toe in-out orientation was assessed with the GaitRite gait analysis system during slow and fast walking trials over a 6-meter walkway. Pearson correlation analysis was used to examine the relationship between joint ROM and gait angle at both walking speeds. Intra- and inter-rater reliability were assessed, and simple linear regression was conducted to explore these relationships. Results: Intra-rater reliability demonstrated high reliability (0.84<ICC<0.94), while inter-rater reliability (0.44<ICC<0.83) exhibited moderate to high reliability. Significant correlations were found between the hip joint's range of motion and the gait angle at slow walking speed. Similar results were observed at fast walking speed for the hip joint. Multiple regression analysis revealed that the neutral angle of the hip joint (β=0.660, p<0.001) and the neutral angle of the knee joint (β=0.284, p=0.034) significantly contributed to the toe-out angle. Conclusions: Our findings indicate a significant correlation between the range of motion of the hip joint and toe in-out orientation. A decrease in the hip joint internal rotation angle was associated with a decrease in toe in-out, while an increase in the mid-angle was associated with an increase in toe in-out.

• Korean Journal of Occupational Health Nursing
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• v.33 no.3
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• pp.83-94
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• 2024

Purpose: This study aimed to investigate the effects of rehabilitation hospital nurses' perception of patient safety culture, nursing professionalism, and nursing work environment on patient safety nursing activities. Methods: A cross-sectional design was used with a convenience sample of 230 nurses with more than six months of experience working in rehabilitation hospitals located in D Metropolitan City, South Korea. Data were collected from October 23 to 31, 2023 through a self-administered questionnaire and analyzed by descriptive statistics, independent t-test, one-way ANOVA with post-verification of Scheffé test, Pearson's correlation coefficient, and multiple stepwise regression analysis using SPSS 28.0. Results: The average scores were 3.73±0.35 for perception of patient safety culture, 3.54±0.47 for nursing professionalism, 2.67±0.49 for nursing work environment, and 4.68±0.45 for patient safety nursing activities. Patient safety nursing activities was significantly positively correlated with perception of patient safety culture, nursing professionalism, and nursing work environment. Experience of reporting incidents (β=.19, p=.002), communication and procedure (β=.18, p=.003), frequency of reporting (β=.18, p=.002), total clinical experience (β=.17, p=.004), patient safety (β=.17, p=.005), and direct supervisor/manager (β=.17, p=.008) affected patient safety nursing activities in rehabilitation hospitals. Conclusion: Perception of patient safety culture may increase rehabilitation hospital nurses' patient safety nursing activities.

• Food Science of Animal Resources
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• v.44 no.5
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• pp.1181-1194
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• 2024

This study assessed and compared meat quality and fiber characteristics of longissimus lumborum (LL), psoas major (PM), and semimembranosus muscles among Hanwoo (HW), Jeju black (BL), and their crossbred (BH) cattle. Twelve carcasses from each breed (36 in total) were used in this study. BL and BH had higher moisture and crude ash contents and lower crude fat and protein contents than HW, regardless of the muscle type. BL had higher CIE a^*, cooking loss, and shear force values than did the other breeds for all muscle types. The muscle fiber size (cross-sectional area) of BL and BH was larger than that of HW for all muscle types. Type IIX was the dominant muscle fiber type in both BL and BH, regardless of muscle type; however, HW had the highest composition of type I compared to the other types (IIA, IIAX, and IIX) in PM. Higher total fiber density was observed in the LL and PM muscles of HW than in those of BL and BH. Meat quality and muscle fiber characteristics of BL and BH were distinct from those of HW.

• Clinical and Experimental Vaccine Research
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• v.13 no.2
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• pp.121-131
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• 2024

Purpose: The global burden of disease and mortality is greatly influenced by malaria, particularly in children. Nigeria alone accounts for about 25% of global malaria cases and fatalities. Despite efforts to control and eliminate malaria, conventional treatments have limitations, prompting the need for a vaccine. However, while efforts have focused on researching and developing malaria vaccines, less attention has been given to public acceptance and preparedness for vaccination. Materials and Methods: The study employed a cross-sectional approach to assess the knowledge, perceptions, and readiness of caregivers towards the malaria vaccine. Data were collected through a physical and online survey among a representative sample of caregivers across the six geopolitical regions of Nigeria. The data was analyzed using principal component analysis and percentages. Results: Out of 347 respondents, 180 (51%) men, 165 (46.6%) women, 2 (0.5%) transgender, 156 (45%) rural settlers, and 191 (55%) urban settlers were identified in this study. The study reported an overall acceptance rate of 78.4% and 21.6% resistance rate. The age group between 21-30 years recorded the highest 207 (59.6%). A significant number of participants, 252 (59.6%), held at least a higher or post-secondary certificate, out of which 193 (55.6%) demonstrated strong readiness to accept the malaria vaccine. The study showed that fear of adverse effects was the main reason for malaria vaccine resistance among caregivers. Conclusion: This study's findings offer valuable insights into caregivers' knowledge about the malaria vaccine, highlighting the factors that impact the acceptance of the malaria vaccine.