• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.18 no.2
• /
• pp.157-169
• /
• 2023

This study examined the effect of entrepreneurial orientation on creative behavior and the mediating effect of knowledge sharing behavior in the relationship between entrepreneurial orientation and creative behavior. In particular, this study examined the moderating effect of leader-member exchange (LMX) in the relationship between entrepreneurial orientation and creative behavior. In this study, after distributing 500 questionnaires to executives and employees working at small and medium-sized companies in Seoul and Gyeonggi-do, 259 questionnaires were used for hypothesis verification, excluding 38 unfaithful or missing responses. The analysis results are as follows. First, it was found that entrepreneurial orientation had a significant positive (+) effect on creative behavior. Second, it was found that entrepreneurial orientation had a significant positive (+) effect on knowledge sharing behavior. Third, knowledge sharing behavior was found to have a significant positive (+) effect on creative behavior. Fourth, knowledge sharing behavior was found to play a partial mediating role in the relationship between entrepreneurial orientation and creative behavior. Finally, it was found that LMX strengthened the positive (+) relationship between entrepreneurial orientation and creative behavior. The theoretical implications of this study are as follows. First, this study makes a theoretical contribution in that it revealed the mediating effect of knowledge-sharing behavior in the relationship between entrepreneurial orientation and creative behavior through empirical analysis of corporate members. Next, this study has theoretical implications in that it revealed that LMX strengthens the positive (+) relationship between entrepreneurial orientation and creative behavior. On the other hand, the practical implications of this study are as follows. First, companies need to find ways to strengthen the entrepreneurial orientation. Next, companies need to find ways to improve the quality of LMX between bosses and subordinates. Finally, this study discussed research limitations and future research directions.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.15 no.1
• /
• pp.8-15
• /
• 2010

An experiment was conducted to evaluate the biologically adverse effect of increased carbon dioxide in seawater on marine bacteria, Vibrio fischeri. We measured the bioluminescence and cell density at every 6 hours for 24 hours of the whole incubation period after exposing test microbes to a range of $CO_2$ concentration such as 380(Control), 1,000, 3,000, 10,000 and 30,000 ppm, respectively. Significant effect on relative luminescence(RLU) of V. fischeri was observed in treatments with $CO_2$ concentration higher than 3,000 ppm at t=12 h. However, the difference of RLU among treatments significantly decreased with the incubation time until t=24 h. Similar trend was observed for the variation of cell density, which was measured as optical density using spectrophotometer. The results showed that a significant relationship between $CO_2$ concentration and bioluminescence of test microbes was observed for the mean time. However, the inhibition of relative bioluminescence and also cell density could be recovered at the concentration levels higher than 3,000 ppm. The dissolved $CO_2$ can be absorbed directly by cell and it can decrease the intracellular pH. Our results implied that microbes might be adversely affected at the initial growing phase by increased $CO_2$. However, they could adapt by increasing ion transport including bicarbonate and then could make their pH back to normal level. Results of this study could be supported to understand the possible influence on marine bacteria by atmospheric increase of $CO_2$ in near future and also by released $CO_2$ during the marine $CO_2$ sequestration activity.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.13 no.1
• /
• pp.67-82
• /
• 2008

This study was performed to investigate changes in benthic environment and macrobenthic polychaete communities in Gamak Bay where various environmental quality improvement projects have been implemented in recent years. Field surveys were carried out in February, 2005 and February, 2006 and twenty stations were selected to explore whether or not there were between-year differences in biotic and abiotic variables. Of 10 environmental variables measured, only three variables including dissolved oxygen (DO), total ignition loss (IL), acid volatile sulfide (AVS) showed significant between-year differences. Specifically, IL and AVS were, on average, 1.5 and 3 times lower in 2006 compared to those in 2005, respectively, which was more pronounced in the northern part of the bay. A total of 95 polychaete species was sampled from the two sampling occasions. Between-year differences in the number of species, abundance, and diversity were varied from place to place. In the northern part of the bay, fewer species were found in 2006 rather than in 2005, but diversity increased in 2006 due to the reduction in dominance of a few species. On the contrary, in the central part of the bay, the number of species, abundance and diversity prominently increased in 2006. In the southern part of the bay, all the biological indices maintained similarly during the two years. Dominant species in 2005 were such opportunistic or organic pollution indicator species as Lumbrineris longifolia, Capitella capitata, Mediomastus californiensis, Pseudopolydora paucibranchiata, etc. and most of them were mainly distributed in the northern part of the bay and in the proximity of it. In 2006, however, Euchone alicaudata, L. longifolia, Paraprionospio pinnata, Flabelligeridae sp., etc. were dominant and distributed mainly in the central part of the bay. Multivariate analyses showed that the whole polychaete community could be divided into 5 groups reflecting the geographical positions of the sampling stations and temporal variation particularly in the northern part of the bay. According to the results of BIO-ENV procedure, TOC (${\rho}=0.52$) and AVS (${\rho}=0.49$) as a single variable best explained the polychaete community structure. The best combination was made by such variables as TOC, AVS, sorting coefficient, and water temperature (${\rho}=0.60$). In conclusion, between-year differences in biotic and abiotic variables imply that recent efforts for the environmental improvement produced positive influences on the benthic environment of Gamak Bay, particularly the northern part of the bay.

• Journal of Korean Dental Hygiene Science
• /
• v.6 no.2
• /
• pp.79-89
• /
• 2023

Background and Objectives: The prevalence of dementia is steadily increasing each year, and preceding studies continue to explore the association between dementia and oral health. Dental hygienists require specialized competencies to provide appropriate dental healthcare services, necessitating the development of a tool for the objective measurement of their knowledge levels. This study aimed to develop a knowledge assessment tool for dental hygienists concerning considerations for dental care for patients with dementia. Methods: The study constructed preliminary items based on a literature review and then conducted expert validation, a pilot survey, and the main survey. The main survey was conducted among 220 dental hygienists. Validity and reliability analyses were conducted with the collected data to select the final items, and the correctness rates for each selected item were verified. Results: As a result of the analysis of the collected data, 18 items were eliminated out of a total of 40 preliminary items, leaving a total of 6 factors and 22 items. The Cronbach's α value for the selected items was 0.791. The six factors are as follows: 'Considerations during dental treatment for dementia patients' (5 items), 'medication side effects in dementia patients' (4 items), 'oral care methods for dementia patients' (4 items), 'communication with dementia patients' (4 items), 'psychological reactions of dementia patients' (3 items), and 'guidance for dementia patients' (2 items). The item with the highest correctness rate was item 2 of the 'guidance for dementia patients' category at 98.6%, while the item with the lowest correctness rate was item 2 of the 'psychological reactions of dementia patients' category at 5.9%. Conclusion: This study validated the reliability and validity of the knowledge assessment tool, which lays the foundation for future research on dental hygienists and dementia. It contributes essential data for ongoing education, development of educational programs, and establishing operational guidelines in healthcare institutions.

• Journal of the Korean Society of Radiology
• /
• v.18 no.3
• /
• pp.187-201
• /
• 2024

Osteoporosis is a major health issue globally, often remaining undetected until a fracture occurs. To facilitate early detection, deep learning (DL) models were developed to classify osteoporosis using abdominal computed tomography (CT) scans. This study was conducted using retrospectively collected data from 3,012 contrast-enhanced abdominal CT scans. The DL models developed in this study were constructed for using image data, demographic/clinical information, and multi-modality data, respectively. Patients were categorized into the normal, osteopenia, and osteoporosis groups based on their T-scores, obtained from dual-energy X-ray absorptiometry, into normal, osteopenia, and osteoporosis groups. The models showed high accuracy and effectiveness, with the combined data model performing the best, achieving an area under the receiver operating characteristic curve of 0.94 and an accuracy of 0.80. The image-based model also performed well, while the demographic data model had lower accuracy and effectiveness. In addition, the DL model was interpreted by gradient-weighted class activation mapping (Grad-CAM) to highlight clinically relevant features in the images, revealing the femoral neck as a common site for fractures. The study shows that DL can accurately identify osteoporosis stages from clinical data, indicating the potential of abdominal CT scans in early osteoporosis detection and reducing fracture risks with prompt treatment.

• Korean Journal of Ecology and Environment
• /
• v.57 no.1
• /
• pp.1-16
• /
• 2024

Most wetlands worldwide have suffered from extensive human exploitation. Unfortunately they have been less explored compared to river and lake ecosystems despite their ecological importance and economic values. This is the same case in Korea. This study was aimed to estimate the assemblage attributes and distribution characteristics of benthic macroinvertebrates for fifty wetlands distributed throughout subtropical Jeju Island in 2021. A total of 133 taxa were identified during survey periods belonging to 53 families, 19 orders, 5 classes and 3 phyla. Taxa richness ranged from 4 to 31 taxa per wetland with an average of 17.5 taxa. Taxa richness and abundance of predatory insect groups such as Odonata, Hemiptera and Coleoptera respectively accounted for 67.7% and 68.2% of the total. Among them Coleoptera were the most diverse and abundant. Taxa richness and abundance did not significantly differ from each wetland type classified in accordance with the National Wetland Classification System. There were three endangered species (Clithon retropictum, Lethocerus deyrolli and Cybister (Cybister) chinensis) and several restrictively distributed species only in Jeju Island. Cluster analysis based on the similarity in the benthic macroinvertebrate composition largely classified 50 wetlands into two major clusters: small wetlands located in lowland areas and medium-sized wetlands in middle mountainous regions. All cluster groups displayed significant differences in wetland area, long axis, percentage of fine particles and macrophyte composition ratio. Indicator Species Analysis selected 19 important indicators with the highest indicator value of Ceriagrion melanurum at 63%, followed by Noterus japonicus (59%) and Polypylis hemisphaerula (58%). Our results are expected to provide fundamental information on the biodiversity and habitat environments for benthic macroinvertebrates in wetland ecosystems, consequently helping to establish conservation and restoration plans for small wetlands relatively vulnerable to human disturbance.

• Journal of Nutrition and Health
• /
• v.57 no.1
• /
• pp.153-169
• /
• 2024

Purpose: The main goal of this study was to identify the impact of coronavirus disease 2019 (COVID-19) on grocery purchases (i.e., fresh and processed foods by grain, vegetable, fruit, seafood, and meat categories) in Korea. To understand the specific impact of COVID-19, the study period was divided into 3 segments: PRE-COVID-19, INTER-COVID-19, and POST-COVID-19. Methods: We used the microdata of household income and expenditure from Statistics Korea (KOSTAT), representing households across the country. The data comprised monthly grocery expenditure data from January 2019 to September 2022. First, we compared the PRE-COVID-19 period to INTER-COVID-19 and then INTER-COVID-19 to POST-COVID-19 and used multiple regression analysis. The covariates used were the gender and age of the head of the household, the household's monthly income, the number of family members, the price index, and the month (dummy variable). Results: The expenditures on all grocery categories except fresh fruit increased from PRE-COVID-19 to INTER-COVID-19. From INTER-COVID-19 to POST-COVID-19, almost all grocery category spending declined, with processed meat being the only exception. Most purchases of protein sources, increased during INTER-COVID-19 compared to PRE-COVID-19, while ham/sausage/bacon for meat protein, fish cakes and canned seafood for seafood protein, and soy milk for plant-based protein did not decrease during POST-COVID-19 compared to INTER-COVID-19. Conclusion: These results show an overall increase in in-home grocery expenditure during COVID-19 due to an increase in eating at home, followed by a decrease in this expenditure in the POST-COVID-19 period. Among the trends, the protein and highly processed convenience food categories did not see a decline in spending during the POST-COVID-19 period, which is a reflection of the preferences of consumers in the post-COVID-19 period.

• Journal of agricultural medicine and community health
• /
• v.49 no.1
• /
• pp.1-12
• /
• 2024

Objectives: Presenteeism is known to be a much more economically damaging social cost than disease rest while going to work despite physical pain. Since COVID-19, social discussions on the sickness benefit have been taking place as a countermeasure against presenteeism, and in particular, farmers and fishermen do not have an institutional mechanism for livelihood support when a disease other than work occurs. This study attempted to examine the relationship between agricultural, fishing, and forestry workers and presenteeism using the 6th Korean Work Conditions Survey. Methods: From October 2020 to January 2021, data from the 6th working conditions survey conducted on 17 cities and provinces in Korea were used, and a total of 34,981 people were studied. Control variables were gender, age, self-health assessment, education level, night work, shift work, monthly income, occupation, working hours per week, and employment status. Results: As a result of the analysis, farmers and fishermen showed the characteristics of the self-employed and the elderly, and as a result of the regression analysis, when farmers and fishermen analyzed the relationship with presenteeism tendency compared to other industry workers, farmers and fishermen increased by 23% compared to other industry groups. Conclusion: This study is significant in that it has representation by utilizing the 6th working conditions survey and objectively suggests the need for a sickness benefit for farmers and fishermen who may be overlooked in the sickness benefit.

• Journal of Korea Water Resources Association
• /
• v.57 no.9
• /
• pp.633-643
• /
• 2024

Many coastal countries have developed and used a wide range of technologies and policy measures to protect freshwater aquifers and groundwater resources from seawater intrusion, and have established and implemented a foundation to legally and institutionally support them. This study covers coastal states in the eastern United States, the Netheland, India and Japan. The goal of this study is to analyze each country's legal and policy measures for coastal groundwater management. By introducing Jeju Island's groundwater standard level system, we aim to provide a basis for future discussions on groundwater management measures not only in Jeju Island but also in coastal areas of Korea. As a result of the analysis, despite the various contents and aspects of coastal groundwater management based on local issues and characteristics around the world, in order to achieve the common goal of securing a stable amount of groundwater withdrawal and preventing seawater intrusion and to maximize the efficiency of groundwater management, it is understood that attempts are being made to establish optimal management measures, laws, systems, and policies based on several key factors. First, considering the hydrogeological characteristics and status of coastal groundwater, a separate special management system is being established and implemented within the scope of the national groundwater management system. In addition, preventing and maintaining groundwater level decline through limiting the amount of groundwater withdrawal and preventing seawater intrusion are key policy goals and policy tools, and it is suppored by research and development. Finally, tt was found that synergy effects are being sought by using various other policy tools and measures in a complex manner.

• Journal of Life Science
• /
• v.34 no.9
• /
• pp.609-619
• /
• 2024

Neurodegenerative diseases are marked by the accumulation of toxic misfolded proteins in neurons. Therefore, strategies for the effective prevention and clearance of aggregates are crucial for therapeutic interventions. Cytoplasmic dynein plays a crucial role in the clearance of aggregates by transporting them to the cell center, where lysosomes are enriched and the aggregates undergo extensive autophagic degradation. Previously, we reported evidence for the activation of dynein by N-acetylglucosamine kinase (NAGK) and Reln. In the present study, we explored the effects of NAGK and Reln upregulation on the clearance of aggregates. To upregulate NAGK and Reln genes in HEK293T cells (a human embryonic kidney cell line), CRISPR/dCas9 activation systems (CASs) were used with specific plasmids encoding target-specific 20 nt guide RNA. The effects of this genetic modulation were analyzed in Huntington's disease cellular models, including HEK293T cells and primary mouse cortical cells, where external mutant huntingtin (mHtt, Q74) aggregates were induced. The results showed that the CAS activation of NAGK or Reln, or their combination, significantly reduced the proportion of cells with Q74 aggregates (aggresomes). This effect was reversed by Ciliobrevin D (a dynein inhibitor) and chloroquine (an autophagy inhibitor), indicating the role of dynein-mediated autophagy in aggregate clearance. These findings provide the basis for therapeutic strategies aimed at enhancing neuronal health through targeted gene activation.