• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.81-93
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• 2019

Phytoplankton is one of the important primary producers providing organic matter through photosynthesis in aquatic environments. In order to determine a temporal and spatial variation in primary productivity after weir construction in the Nakdong River, we investigated carbon uptake rates using in-situ $^{13}C$ labeling experiments and identified algal communities contributing to primary productivity using HPLC-CHEMTAX analysis from October to December, 2017. The primary productivity gradually decreased from fall to early winter season ($249{\sim}933mgC\;m^{-2}d^{-1}$ in October, $64{\sim}536mgC\;m^{-2}d^{-1}$ in November and $60{\sim}274mgC\;m^{-2}d^{-1}$ in December, respectively). This is attributed to the temporally declining light intensity and the decreasing biomass and physiological activity of phytoplankton in winter. The contribution of diatoms to the phytoplankton community in the Nakdong River was approximately 63% at all the sampling sites and seasons, while the contribution of cryptophytes increased from 9% in October to 32% in November and December. The temporal changes in the primary productivity and the dominant phytoplankton species in the mid and downstream weirs of the Nakdong River was investigated for the first time, after construction of the weirs, and major environmental factors controlling the temporal variation in primary productivity and phytoplankton communities were identified in this study. We suggest that seasonal field investigations will provide further information on the major environmental factors which affect the annual variation of primary productivity and phytoplankton communities.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.564-575
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• 2021

This study explored the relationship between self-esteem of soldiers and adaptation to military life and verified the mediating effect of depression in such relationships. The subjects of this study were 230 Army soldiers based in Gangwon-do. The collected data were analyzed through descriptive statistics, difference verification, hierarchical regression analysis, and the mediating effect method. First, according to the difference verification, the level of adaptation to military life was higher when the health status was good, among the general characteristics, when the family health was good, when the soldiers had friends, when they were sergeants rather than privates or corporals, and when they had someone to discuss their concerns. Second, the hierarchical regression analysis showed that the soldiers adapted to the military life better with better health status, when they served as combat soldiers, and when they had someone to consult. In addition, the higher the self-esteem, the main variable, and the lower the depression level, the higher the level of adaption to military life. Third, as a result of the mediating effect analysis, depression was found to have a partial mediating effect in the relationship between self-esteem and military adaptation. Therefore, this study presented practical alternatives to increase self-esteem and reduce depression as a factor to cope with soldiers' adaptation to military life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.511-519
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• 2021

This study examined the effects of the levels of depression and oral health on the quality of life in workers participating in a self-sufficiency program in the Seoul metropolitan area. As for the study method, a questionnaire survey was conducted from July 26 to September 5, 2020, targeting 569 workers participating in a self-sufficiency program. Depression, Perio-Quotient Index, self-diagnosed oral symptoms, and oral health quality of life were the survey items investigated. The results were as follows. In the workers with systemic diseases, depression, Perio-Quotient Index, oral symptoms, and oral health quality of life were all negative. The level of depression was highly negative in both Perio-Quotient Index, oral symptoms, and oral health quality of life, showing statistically significant differences. In addition, depression showed a strong negative correlation with the Perio-Quotient Index, oral symptoms, and oral health quality of life. Depression, Perio-Quotient Index, and particularly oral symptoms negatively affected oral health and the quality of life. As workers participating in a self-sufficiency program are vulnerable to oral health problems, oral health education is required for the correct awareness and management of oral health, and oral health policy improvement for socially vulnerable groups is essential to ensure continued oral health management.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.27-34
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• 2021

This study aims to provide basic data to identify the effects of oral health behavior and autologous oral health symptoms on factors that affect quality of life of COVID-19 (coronavirus disease 19) depression. This study collected data from July 2020 to September 2020, the research method was finally analyzed for 89 people in the group of depression non-increase and 86 people in the group of depression due to COVID-19. As an analysis method, oral health behavior, autologous oral health symptom and quality of life were compared, and the hierarchical regression analysis was implemented to check the effect of depression on the quality of life. As a result, the effects of depression (��=-0.155, p=0.012) and autologous oral health symptoms (��=0.524, p<0.001) were significant as a result of controlling demographic characteristics and checking the effects on quality of life. Therefore, it is urgent to develop programs related to the mental health of the community to relieve depression and anxiety with COVID-19, and public relations activities will be needed to relieve anxiety about dental visits so that dental treatment can be received at an appropriate time.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.27-35
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• 2021

The study intends to identify the effects of infrastructure property on an apartment house by analyzing the price variation affected by factors constituting the quality of the transit services of each individual station in urban railway system based on hedonic price model. The research findings indicate that the prices depending on the transit users have increased from 7.8% to 12.2% in Seoul and decreased from 6.1% to 12.9% in Gyeonggi, which implies that a lower number of transfer users has a positive effect on housing prices in Seoul unlike Gyeonggi. It also is noteworthy that the distance to the urban railway station had a negative effect on housing prices in Seoul and positive effect in Gyeonggi. Taking these results together, in Seoul, the increase in the number of transit users had a negative effect on neighborhood housing prices. When analyzed by segments, however, an additional negative effect was observed only in the apartments located within the radius of 100 meters. It is also found that the impact of transit users varies according to the regional characteristics, such as the density of commercial facilities and the population density, and the spatial extent of negative effect also showed regional differences. These results provide implications for the planning of new stations, new cities, and land use of existing areas around stations.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.565-576
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• 2011

This study was conducted to describe forest stand characteristics of the habitats of Allium victorialis var. platyphyllum population from the ecological analysis of classification of vegetation types, importance values, species diversity, interspecific association and community similarity in Ulleung Island and Mt. Hambaek, in which investigated by 48 plots ($10m{\times}10m$). The vegetation studied was classified into 1 community group, 2 communities, 2 groups and 3 subgroups for a species unit and divided by 5 units for a vegetation unit. In the Fagus engleriana group (vegetation unit 1, 2 and 3), importance value of A. victorialis var. platyphyllum in herb layer showed relatively higher value than other units. Importance value of A. victorialis var. platyphyllum in herb layer had higher value. In the analysis of interspecific association, most of the species associated positively to A. victorialis var. platyphyllum belonged to habitat features of valley area and sub-alpine zone. Therefore, it was considered that the growing environment of A. victorialis var. platyphyllum population was closely correlated to soil moisture and air humidity.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.131-138
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• 2021

The purpose of this study is to derive the implications of Grit research by analyzing domestic research trends on Grit, which is a non-cognitive subject that has been actively researched in Korea recently in order to grasp the achievements so far and to seek directions for research. The analysis method was analyzed according to the pre-set criteria (annual publication status, research subject, research method, research topic, etc.) which were focusing on KCI listed and KCI excellent Grit papers among domestic academic papers of 'RISS'. As a result of the study, from 2013 to 2019, a total of 203 papers were searched and published in 92 domestic journals. Beside that, the subjects of the study, 88 cases (43.35%) were college students and 180 cases (88.67%) were quantitative studies as the research method. So, the most common research method was quantitative research. As a quantitative research method, the structural relationship between Grit and other variables, mediating effect, difference verification, and moderation effect verification were shown in order, and qualitative research has been conducted since 2017 to develop the concept of Grit, the Grit scale, and the corresponding factor structure and validity. This study will contribute to the educational field by presenting the implications of research on the development of Grit in Korea.

• Journal of The Korean Society of Clinical Toxicology
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• v.19 no.1
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• pp.8-16
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• 2021

Purpose: This study was conducted to analyze the social factors influencing the 'authenticity of suicidal ideation' based post-suicidal care programs in emergency departments (EDs). Methods: This retrospective study was an analysis using the data of patients who had attempted suicide and visited the ED in tertiary urban hospitals from January 1, 2016, to December 31, 2018. The variables examined included gender, age, history of previous psychiatric disease, suicide method, and the number of previous attempts. Univariate and multivariate logistic regression analyses were conducted to identify factors influencing the registration rate for the community-based post-suicide care program. Results: Overall,1,460 suicides were analyzed, 177 (1.16%) showed a high authenticity of suicide. The social factors influencing the authenticity of suicide intent were the unmarried status of men and women, joblessness, history of mental illnesses, more than two previous suicide attempts, the influence of alcohol, and an attempt to commit suicide after midnight more specifically between 24:00 to 6:00 hours in the morning (p<.05). The factors influencing the severity of the condition of high authenticity suicide patients were low Glasgow coma scores (12 points or less), lactate levels, and oxygen saturation observed in the patients who were admitted to the intensive care unit for treatment and died (p<.05). Conclusion: The need for evidence-based preventive measures and early assessment tools at the emergency medicine level is emphasized to reduce the rate of suicide attempts. If the results of this study are used in the management of suicide prevention, the evaluation of the authenticity of suicide intent will be more likely to be made at the emergency medicine level, allowing the severity to be assessed earlier.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.572-586
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• 2021

With the advent of the 4th Industrial Revolution, the modern economy is transforming into a service-oriented economic society, and there is a growing need for companies to reorganize organizational culture, values, and human resources to suit the changing environment. Especially, even when times change, human capital is the most important factor in maintaining sustainable development and Corporate value, since all work is done by people. Therefore, in this study, in order to recognize the importance of human resources and verify the appropriate human resources for the changing service economy era, we reviewed the literature and that drew the human resources suitable for the recent service economy era Based on this, an empirical study was conducted on whether the suggested human resources factors were useful. To this end, a feasibility analysis, reliability analysis, correlation analysis, confirmatory factor analysis, and reference validity were conducted by dividing into a preliminary survey and a main survey. As a result, it was finally drawn with 30 items, 7 factors. The results of this study are expected to be used as basic data in various fields of research on human resources in the service economy era, and in-depth empirical studies are needed in the future.

• Knowledge Management Research
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• v.22 no.1
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• pp.39-56
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• 2021

In the current knowledge society, mobile devices have become a useful tool for performing work. In the context of COVID-19 which has made digital transformation inevitable, the importance of mobile work behaviors - performing work tasks through mobile devices - is further highlighted. Drawing from the behavioral immune system theory and cognitive appraisal theory of emotions, this study proposes that individual workers' concern about getting infected by COVID-19 will be negatively related to job satisfaction but positively related to mobile work behaviors. We further propose that leaders' communality and agency trait will be positively related to both job satisfaction and the increase of mobile work behaviors. Analyses of a matched dataset comprising survey data and mobile application usage data from 407 workers showed that their leaders' agency and communality were significantly related to the workers' job satisfaction. However, their mobile productivity was significantly related only to the communality of their leaders. The results of this study will provide useful theoretical and practical implications for researchers and managers who aim to understand and promote the technology adoption and knowledge productivity of workers in a pandemic situation.