• Korean Journal of Psychosomatic Medicine
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• v.30 no.2
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• pp.127-136
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• 2022

Objectives : The study aimed to identify factors associated with suicidal attempt in Korean adults experiencing thoughts of suicide. Methods : This study analyzed outcomes of suicidal behavior in the Korea National Health and Nutrition Examination Survey (KNHANES) 2015, 2017, and 2019. This survey was administered by the Korea Centers for Disease Control and Prevention (KCDC). The suicidal idea group was divided into individuals who had attempted suicide (n=92) and those who had not (n=831). Complex samples crosstabs analysis was conducted to compare the two groups' sociodemographic, psychiatric, and clinical characteristics. In addition, factors related to attempted suicide were investigated using complex samples logistic regression analysis. Results : The attempted suicide group had significantly higher rates of depression, recent psychiatric counseling, and suicidal plan (p<0.001) than the non-attempting group. In addition, the groups differed significantly in the frequency of binge drinking and smoking (p<0.05). Adjusted multivariate analysis revealed that the presence of a suicidal plan (Odds ratio [OR]=8.46, 95% Confidential Intervals [CI]=4.72-15.00), daily binge drinking (OR=3.14, 95% CI=1.26-7.84), psychiatric counseling within the past year (OR=3.03, 95% CI=1.75-5.23), low income level (OR=2.89, 95% CI=1.17-7.10), and history of depression (OR=2.39, 95% CI=1.29-4.42) were significantly associated with suicidal attempt. Conclusions : Factors associated with suicidal attempt among suicidal ideators in the general Korean population were identified across all sociodemographic, psychiatric, and clinical variables. Assessment of and intervention in suicidal plan, binge drinking, income level, and depression might prevent progression to suicidal attempt among those contemplating suicide.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.461-472
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• 2022

Natural and anthropogenic factors cause forest types to continuously change. Since the ratio of forest area by forest type is important information for identifying the characteristics of national forest resources, an accurate understanding of the prospect of forest type change is required. The study aim was to use National Forest Inventory (NFI) time-series data to understand the characteristics of forest type change and to estimate future prospects of nationwide forest type change. We used forest type change information from the fifth and seventh NFI datasets, climate, topography, forest stand, and disturbance variables related to forest type change to analyze trends and characteristics of forest type change. The results showed that the forests in Korea are changing in the direction of decreasing coniferous forests and increasing mixed and broadleaf forests. The forest sites that were changing from coniferous to mixed forests or from mixed to broadleaf forests were mainly located in wet topographic environments and climatic conditions. The forest type changes occurred more frequently in sites with high disturbance potential (high temperature, young or sparse forest stands, and non-forest areas). We used a climate change scenario (RCP 8.5) to establish a forest type change model (SVM) to predict future changes. During the 40-year period from 2015 to 2055, the SVM predicted that coniferous forests will decrease from 38.1% to 28.5%, broadleaf forests will increase from 34.2% to 38.8%, and mixed forests will increase from 27.7% to 32.7%. These results can be used as basic data for establishing future forest management strategies.

• Journal of the Korean Society of Radiology
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• v.16 no.1
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• pp.35-43
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• 2022

In this study, a survey was conducted and analyzed to find out the satisfaction of online classes among students enrolled in the radiology department of a university located in Busan city. As a result, in terms of satisfaction with online classes, male scores were higher, but there was no statistically significant difference. In the interdisciplinary system, the satisfaction score of the students enrolled in Bachelor's degree was high, and there was a statistically significant difference except for the satisfaction of learning participation (p<0.001, p<0.05). For class satisfaction by grade level, Senior had higher scores, and there were statistically significant differences except for learning participation satisfaction (p<0.001, p<0.01, p<0.05). In the satisfaction survey according to the number of lectures, the scores of the students who took 4-7 lectures were found to be high except for the satisfaction of learning participation, and there was a statistically significant difference (p<0.01, p<0.05). In the method of communication with the instructor, students who used e-mail showed high scores, and there was a statistically significant difference in lecture satisfaction (p<0.05). In the correlation analysis between sub-variables for online classes, statistically significant correlations were established in all areas. Most of the students preferred class methods such as recorded classes and classes using external content such as YouTube, and when asked about the merits of online classes, many students answered that the advantages of online classes were repetitive classes and no restrictions on time and place. When asked about the shortcomings of online classes, many students answered that it was a lack of concentration and lack of communication with the instructor. This study was conducted to provide basic data to improve the satisfaction of online classes that will increase in the future. Therefore, based on the results of this study, it is expected that more quality online classes will be produced so that students' satisfaction with online classes can be improved.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.405-417
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• 2022

The purpose of this study was to describe the photosynthetic features of Prunus maximowiczii and Prunus serrulate Lindl. var. pubescens (Makino) Nakai in response to drought stress. Specifically, we studied the effects of drought on photosynthetic ability and photosystem II activity. Drought stress (DS) was induced by cutting the water supply for 30 days. DS decreased the moisture contents in the soil, and between the 10th and 12th days of DS, both species had 10% or less of x., After the 15th day of DS, it was less than 5%, which is a condition for disease to start. We observed a remarkable decrease of maximum photosynthesis rate starting from 10th day of DS; the light compensation point was also remarkable. Dark respiration and net apparent quantum yield decreased significantly on the 15th day of DS, and then increased on the 20th day. In addition, the stomatal transpiration rate of P. maximowiczii decreased significantly on the15th day of DS, and then increased on the 20th day. Water use efficiency increased on the 15th day of DS, and then decreased on the 20th day. The stomatal transpiration rate of P. serrulate decreased significantly on the 20th day of DS, and then increased afterward, while its water use efficiency increased on the 20th day of DS, and then decreased afterward. These results indicate that the closure of stoma prevented water loss, resulting in a temporary increase of water use efficiency. Chlorophyll fluorescence analysis detected remarkable decreases in the functional index (PI_ABS) and energy transfer efficiency in P. maximowiczii after the 15th day of DS. Meanwhile, photosystem II activity decreased in P. serrulate after 20 days of DS. In addition, Ts-Ta, PI_ABS, DI_O/RC, ET_O/RC followed similar trends as those of the soil moisture content and photosynthetic properties, indicating that they can be used as useful variables in predicting DS in trees.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.365-373
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• 2022

We compared carbon stocks in tree biomass and soils of Quercus acutissima, Q. mongolica, Q. serrata, and Q. variabilis stands. A total of 531 plots (Q. acutissima: 110 plots, Q. mongolica: 177 plots, Q. serrata: 96 plots, Q. variabilis: 148 plots) were examined between 2016 and 2021 to determine the tree biomass and soil carbon stocks throughout the country. The carbon stocks of tree biomass were significantly higher in Q. mongolica (mean stand age, 57 years, 144.9 Mg C ha^-1) than in Q. variabilis (mean stand age, 43 years, 123.7 Mg C ha^-1), Q. serrata (mean stand age, 43 years, 120.1 Mg C ha^-1), and Q. acutissima (mean stand age, 36 years, 113.2 Mg C ha^-1) stands. The soil carbon concentration was significantly higher in Q. mongolica (A: 43.1 mg C g-1) than in Q. serrata (31.0 mg C g-1), Q. variabilis (25.31 mg C g-1), and Q. acutissima (24.4 mg C g-1) stands. The soil carbon stocks were significantly higher in Q. mongolica (116.8 Mg C ha^-1) than in Q. acutissima (49.3 Mg C ha^-1) stands. Total carbon stocks of tree biomass and soil were highest in Q. mongolica (262 Mg C ha^-1), followed by Q. serrata (218 Mg C ha^-1), Q. variabilis (211 Mg C ha^-1), and Q. acutissima (163 Mg C ha^-1) stands. Multiple linear regressions were performed to estimate the total carbon stocks of the four Quercus spp., and results showed that total carbon stocks increased with increasing elevation, mean diameter at breast height, and basal areas. Basal area and elevation of Quercus spp. stands were important explanatory variables based on multiple linear regressions for estimating carbon stocks.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.133-149
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• 2022

Existing domestic studies on estimating rice yield were mainly implemented at the level of cities and counties in the entire nation using MODIS satellite images with low spatial resolution. Unlike previous studies, this study tried to estimate rice yield at the level of eup-myon-dong in Gimje-si, Jeollabuk-do using Sentinel-2 satellite images with medium spatial resolution, rainfall and soil data, and then to evaluate its accuracy. Five vegetation indices such as NDVI, LAI, EVI2, MCARI1 and MCARI2 derived from Sentinel-2 images of August 1, 2018 for Gimje-si, Jeollabuk-do, rainfall and paddy soil-type data were aggregated by the level of eup-myon-dong and then rice yield was estimated with gamma generalized linear model, an expanded variant of multi-variate regression analysis to solve the non-normality problem of dependent variable. In the rice yield model finally developed, EVI2, rainfall days in September, and saline soils ratio were used as significant independent variables. The coefficient of determination representing the model fit was 0.68 and the RMSE for showing the model accuracy was 62.29kg/10a. This model estimated the total rice production in Gimje-si in 2018 to be 96,914.6M/T, which was very close to 94,470.3M/T the actual amount specified in the Statistical Yearbook with an error of 0.46%. Also, the rice production per unit area of Gimje-si was amounted to 552kg/10a, which was almost consistent with 550kg/10a of the statistical data. This result is similar to that of the previous studies and it demonstrated that the rice yield can be estimated using Sentinel-2 satellite images at the level of cities and counties or smaller districts in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.5
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• pp.69-79
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• 2022

This study aims to assess the current understanding of the landscape of wind power facilities as renewable energy sources that supply sightseeing, tourism, and other opportunities. Therefore, social media data related to the landscape of wind power facilities experienced by visitors from different regions was analyzed. The analysis results showed that the common characteristics of the landscape of wind power facilities are based on the scale of wind power facilities, the distance between overlook points of wind power facilities, the visual openness of the wind power facilities from the overlook points, and the terrain where the wind power facilities are located. In addition, the preference for wind power facilities is higher in places where the shape of wind power facilities and the surrounding landscape can be clearly seen- flat ground or the sea are considered better landscapes. Negative keywords about the landscape appear on Gade Mountain in Taibai, Meifeng Mountain in Taibai, Taiqi Mountain, and Gyeongju Wind Power Generation Facilities on Gyeongshang Road in Gangwon. The keyword 'negation' occurs when looking at wind power facilities at close range. Because of the high angle of the view, viewers can feel overwhelmed seeing the size of the facility and the ridge simultaneously, feeling psychological pressure. On the contrary, positive landscape adjectives are obtained from wind power facilities on flat ground or the sea. Visitors think that the visual volume of the landscape is fully ensured on flat ground or the sea, and it is a symbolic element that can represent the site. This study analyzes landscape awareness based on the opinions of visitors who have experienced wind power facilities. However, wind power facilities are built in different areas. Therefore, landscape characteristics are different, and there are many variables, such as viewpoints and observers, so the research results are difficult to popularize and have limitations. In recent years, landscape damage due to the construction of wind power facilities has become a hot issue, and the domestic methods of landscape evaluation of wind power facilities are unsatisfactory. Therefore, when evaluating the landscape of wind power facilities, the scale of wind power facilities, the inherent natural characteristics of the area where wind power facilities are set up, and the distance between wind power facilities and overlook points are important elements to consider. In addition, wind power facilities are set in the natural environment, which needs to be protected. Therefore, from the landscape perspective, it is necessary to study the landscape of wind power facilities and the surrounding environment.

• Journal of Intelligence and Information Systems
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• v.29 no.1
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• pp.307-325
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• 2023

Due to the prolonged COVID-19 pandemic, the frequency of people who are tired of living indoors visiting nearby mountains and national parks to relieve depression and lethargy has exploded. There is a place where thousands of people who came out of nature stop walking and breathe and rest, that is the mineral spring. Even in mountains or national parks, there are about 600 mineral springs that can be found occasionally in neighboring parks or trails in the metropolitan area. However, due to irregular and manual water quality tests, people drink mineral water without knowing the test results in real time. Therefore, in this study, we intend to develop a model that can predict the quality of the spring water in real time by exploring the factors affecting the quality of the spring water and collecting data scattered in various places. After limiting the regions to Seoul and Gyeonggi-do due to the limitations of data collection, we obtained data on water quality tests from 2015 to 2020 for about 300 mineral springs in 18 cities where data management is well performed. A total of 10 factors were finally selected after two rounds of review among various factors that are considered to affect the suitability of the mineral spring water quality. Using AutoML, an automated machine learning technology that has recently been attracting attention, we derived the top 5 models based on prediction performance among about 20 machine learning methods. Among them, the catboost model has the highest performance with a prediction classification accuracy of 75.26%. In addition, as a result of examining the absolute influence of the variables used in the analysis through the SHAP method on the prediction, the most important factor was whether or not a water quality test was judged nonconforming in the previous water quality test. It was confirmed that the temperature on the day of the inspection and the altitude of the mineral spring had an influence on whether the water quality was unsuitable.

• Journal of Korea Port Economic Association
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• v.39 no.1
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• pp.65-100
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• 2023

This study examines the effects of organizational trust of the container terminal operators' employee on organizational citizenship behavior and the moderating effect of organizational support in the relationship between the two variables. In order to efficiently achieve the purpose of this study, an empirical analysis was conducted by distributing a literature review and a questionnaire, and the results of the study are as follows... First, the organizational trust of the container terminal operators' employee was found to have a significant positive (+) effect on organizational citizenship behavior, and trust in the company appeared to be more important than trust in the superior, indicating trust in the institutional aspect. This means that formation has more influence on organizational citizenship behavior... Second, it was confirmed that the organizational support of the container terminal operators' employee can lead to active participation in organizational citizenship behavior through the expansion of educational compensatory support. Third, among the organizational support of container terminal operators, emotional support and educational compensatory support were found to have a partial moderating effect on the relationship between organizational trust and organizational citizenship behavior." Emotional support has a moderating effect on caring and active participation behaviors in the relationship between trust in the company and organizational citizenship behaviors, and a moderating effect on caring, active participation, and non-complaining behaviors in the relationship between trust in superiors and organizational citizenship behaviors. It was analyzed that there is Compensatory educational support has a moderating effect on altruistic, caring, active participation, and non-complaining behavior in the relationship between trust in the company and organizational citizenship behavior. It was analyzed that there was a moderating effect on active participation and non-complaining behavior. These analysis results mean that members' trust in the company further increases through the container terminal operator's emotional support and educational reward support. As uncertainty grows, it is very important to increase the trust of organizational members in the organization. sense of belonging to the organization, Emotional support that can increase immersion, improvement of work environment, provision of educational opportunities, and education-compensatory support such as a fair compensation system will increase organizational trust and induce effective organizational citizenship behavior to realize sustainable growth of the organization.

• Korean Association of Arts Management
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• no.51
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• pp.35-73
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• 2019

The purpose of this study is to investigate the effects of culture and arts activities (experience, type, frequency) and participation motivation on subjective well-being and to investigate the mediating effects of learning motivation. For this study, the subject is limited to adults who are leading consumers of culture and art activities can decide what activity to do. By survey, data from 1,000 respondents are used for analysis after applying proportional sampling based on the proportion of sex and age indicated in the population statistics. Exploratory factor analysis and reliability analysis were conducted based on the collected data using SPSS v.22.0. The results obtained from the empirical analysis are as follows. First, regarding culture and art activities (experience, type, frequency) and subjective well-being, the results are as follows. H1. Those who experienced culture and arts activities have higher subjective well-being than non-experienced ones. H2. Participating in culture and art activity increases subjective well-being more than just spectating culture and art programs. H3. Heavy participants in culture and art activities have higher subjective well-being than lighter participants. These results indicate that culture and art activities are important variables that have a positive effect on subjective well-being. Therefore, participating in culture and art activities may be an appropriate way to enhance subjective well-being because they are life experiences that individuals can experience in their daily lives. Second, H4. internal motivation and external motivation, sub-factors of participation motivation in culture and art activities, have a positive effect on subjective well-being, and amotivation has a negative effect on subjective well-being. Therefore, in order to improve subjective well-being, it is important to strive to lower amotivation and increase internal and external motivation. Third, H5. learning motivation has a partial mediating effect on the relationship between participation motivation in culture and art activities and subjective well-being. This result suggests that culture and art activities and education might be helpful for subjective well-being when they are conducted together since participation motivation in culture.