• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.276-286
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• 2022

We carried out this study to provide basic data necessary to establish a management plan for concrete erosion control dams in the future by analyzing results of detailed inspections of aged dams conducted in accordance with 「Guidelines for the Maintenance of the Erosion Control Facility」. We analyzed the results of a detailed inspection of 54 concrete erosion control dams which had been built over 20 years previously, located in private forests of Gyeongsangbuk-do using statistical methods. Having conducted exterior defect investigations, we found 18 dams (33.4%) in need of repair or follow-up measures and 15 dams in which the overall grade was changed due to investigator's corrections; we therefore considered that standardization of related standards and indicators would be necessary. After conducting concrete compression strength tests, we found 19 dams (35.2%) to be below the standard value of 21 MPa, and in particular, we included, in grade A, eight dams which we judged to be in good condition as a result of the exterior defect inspection. There was little clear correlation between the total score and the compressive strength of concrete, but there was a statistically significant difference in the compressive strength by overall grade. After analyzing the changes in the characteristics of the erosion control dams according to the elapsed years after construction, we detected no particular trend in the changes of total score and compressive strength over time. However, the cumulative ratio of the dams that required repair and follow-up measures and the dams below the compression strength standard had a strong positive linear relationship over time, suggesting that it would be possible to identify the aging characteristics of concrete erosion control dams.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.955-968
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• 2021

A water resource plan is routinely based on a natural flow and can be estimated using observed streamflow data or a long-term continuous rainfall-runoff model. However, the watershed with the natural flow is very limited to the upstream area of the dam. In particular, for the ungauged watershed, a rainfall-runoff model is established for the gauged watershed, and the model is then applied to the ungauged watershed by transferring the associated parameters. In this study, the GR4J rainfall-runoff model is mainly used to regionalize the parameters that are estimated from the 14 dam watershed via an optimization process. In terms of optimizing the parameters, the Bayesian approach was applied to consider the uncertainty of parameters quantitatively, and a number of parameter samples obtained from the posterior distribution were used for the regionalization. Here, the relationship between the estimated parameters and the topographical factors was first identified, and the dependencies between them are effectively modeled by a Copula function approach to obtain the regionalized parameters. The predicted streamflow with the use of regionalized parameters showed a good agreement with that of the observed with a correlation of about 0.8. It was found that the proposed regionalized framework is able to effectively simulate streamflow for the ungauged watersheds by the use of the regionalized parameters, along with the associated uncertainty, informed by the basin characteristics.

• Journal of the Korean Institute of Rural Architecture
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• v.24 no.1
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• pp.9-17
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• 2022

Rural spaces are increasingly valuable as areas for introducing renewable energy infrastructure to achieve carbon neutrality. Rural areas are the living grounds of rural residents, and the balance of conservation and development for rural areas is important for the introduction of reasonable facilities. In order to maintain a balance between development and preservation and to introduce reasonable renewable energy facilities, it is necessary to develop a current status survey and an effective survey method to utilize a space capable of introducing renewable energy facilities such as idle land and vacant houses. Therefore, this study was conducted to verify the readability using an unmanned aerial vehicle, and the main results are as follows. The detection of photovoltaic power generation facilities using unmanned aerial vehicles was effective in analyzing the location and area of photovoltaic panels located on the roofs of buildings, and it was possible to calculate the expected power generation by region through the area calculation of photovoltaic panels. The vacant house detection can be used to select an investigation target for an vacant house condition survey as it can identify damage to buildings that are expected to be empty houses, management status, and electricity supply facilities through aerial photos. It is judged that the unmanned aerial vehicle detection capability can be utilized as a method to improve the efficiency of investigation and supplement the data related to solar power generation facilities and vacant houses provided by public institutions. Although this study detected the status of solar power generation facilities and vacant houses through high-resolution aerial image analysis, as a follow-up study, automatic measurement methods using the temperature difference of solar power generation facilities and general characteristics of vacant houses that can be read from the air were investigated. If the deriving research is carried out, it is judged that it will be possible to contribute to the improvement of the accuracy of the detection result using the unmanned aerial vehicle and the expansion of the application range.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.3
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• pp.89-108
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• 2022

The purpose of this study is to reveal the specific current and future shapes of the collaborative network among organizations witch cope the COVID-19 in Korea. For this, this study conducted social network analysis, based on the response data of 73 experts from 36 COVID-19-related organizations. As a result of the analysis, it was confirmed that the Korea Disease Control and Prevention Agency (KDCA) plays a pivotal role as a control tower in coping COVID-19 in all of the analysis of degree, betweenness, and closeness centrality. In addition, the results revealed concrete forms of collaborative relationships among participating organizations in the public and private sectors that constitute the present and future networks centered on the KDCA. Furthermore, this study presented which organizations and relationships should be the focus of establishing a future collaborative network through comparative analysis between the current cooperative network and the network to be built in the future. The analysis results and discussions of this study are expected to be used as useful information for policy development related to collaborative networks that can effectively respond to disasters caused by new diseases in the future.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.247-260
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• 2022

In order to advance theoretical and practical understanding of innovative behaviors and affective commitment to change, this study investigated the relationship among innovation supporting organizational culture, decentralized structure, acceptance of organizational change, and affective commitment to change and tested the mediating effect of acceptance of organizational change in the relationship. Data were collected from 261 employees at H corporation and analyzed to test suggested research hypotheses using SPSS 20.0 and AMOS 20.0. The results are as follows: First, it is found that innovation supporting organizational culture influences positively acceptance of organizational change and affective commitment to change. Second, results show that decentralized structure influences positively acceptance of organizational change, but does not influence innovative behavior. Third, it is found that acceptance of organizational change influences positively affective commitment to change and innovative behavior. Fourth, it is also found that acceptance of organizational change mediates partially the relationship between innovation supporting organizational culture and affective commitment to change and acceptance of organizational change mediates completely the relationship between decentralized structure and affective commitment to change. With these findings, it is confirmed that innovation supporting organizational culture and decentralized structure influence positively affective commitment to change and innovative behavior through acceptance of organizational change. Limitations and suggestions were discussed.

• Journal of Industrial Convergence
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• v.20 no.3
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• pp.99-109
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• 2022

The purpose of this paper is to verify the mediating effect of peer relations and self-esteem in the relationship between the effects of deficiency of children using local children's centers on school life adaptation. The survey subjects were selected from 424 students in the first year of middle school who were used the local children's center, and analyzed using data from the 4th of the local children's center. Summarizing the analysis results, peer relationships were found to have a complete mediating effect in the relationship between deficiency and school life adaptation. Second, it was verified that self-esteem has a partial mediating effect in the relationship between deficiency and school life adaptation. Children using local children's centers experience deficiencies in various areas of society, but as can be seen from the results of this study, it was suggested that they can help adapt to school life by promoting self-esteem and peer relationships. Therefore, we would like to propose the development of programs and practical implications for promoting children's adaptation to school life, and the expansion of the field of children's research using local children's centers.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.3
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• pp.217-226
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• 2022

In the view of the application of high-precision spatial information production, UAV (Umanned Aerial Vehicle)-Photogrammetry has a problem in that it lacks specific procedures and detailed regulations for quantitative quality verification methods or certification of captured images. In addition, test tools for UAV image quality assessment use only the GSD (Ground Sample Distance), not MTF (Modulation Transfer Function), which reflects image resolution and contrast at the same time. This fact makes often the quality of UAV image inferior to that of manned aerial image. We performed MTF and GSD analysis simultaneously using a siemens star to confirm the necessity of MTF analysis in UAV image quality assessment. The analyzing results of UAV images taken with different payload and sensors show that there is a big difference in σ_MTF values, representing image resolution and the degree of contrast, but slightly different in GSD. It concluded that the MTF analysis is a more objective and reliable analysis method than just the GSD analysis method, and high-quality drone images can only be obtained when the operator make images after judging the proper selection the sensor performance, image overlaps, and payload type. However, the results of this study are derived from analyzing only images acquired by limited sensors and imaging conditions. It is therefore expected that more objective and reliable results will be obtained if continuous research is conducted by accumulating various experimental data in related fields in the future.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.563-573
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• 2022

This work aimed to develop a new equation for turbidity (Turb) simulation and prediction using statistical methods based on principal component analysis (PCA) and multiple linear regression (MLR). For this purpose, water samples were collected monthly over a five year period from Cheurfa dam, an important reservoir in Northwestern Algeria, and analyzed for 12 parameters, including temperature (T°), pH, electrical conductivity (EC), turbidity (Turb), dissolved oxygen (DO), ammonium (NH₄⁺), nitrate (NO₃^-), nitrite (NO₂^-), phosphate (PO₄^3-), total suspended solids (TSS), biochemical oxygen demand (BOD₅) and chemical oxygen demand (COD). The results revealed a strong mineralization of the water and low dissolved oxygen (DO) content during the summer period. High levels of TSS and Turb were recorded during rainy periods. In addition, water was charged with phosphate (PO₄^3-) in the whole period of study. The PCA results revealed ten factors, three of which were significant (eigenvalues >1) and explained 75.5% of the total variance. The F1 and F2 factors explained 36.5% and 26.7% of the total variance, respectively and indicated anthropogenic pollution of domestic agricultural and industrial origin. The MLR turbidity simulation model exhibited a high coefficient of determination (R² = 92.20%), indicating that 92.20% of the data variability can be explained by the model. TSS, DO, EC, NO₃^-, NO₂^-, and COD were the most significant contributing parameters (p values << 0.05) in turbidity prediction. The present study can help with decision-making on the management and monitoring of the water quality of the dam, which is the primary source of drinking water in this region.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.187-196
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• 2022

The purpose of this study is to examine the mediating effect of depression in the relationship between the performance of daily activities in the elderly and their life satisfaction. The subjects of the study were 10,097 people from the Survey on the Elderly (2020), and the SPSS 25.0 program was used for data analysis. The main research results that analyzed the elderly's daily life movement performance by dividing it into daily life discomfort and movement performance difficulty are as follows. First, it was confirmed that the effects of discomfort and difficulty in performing daily activities of the elderly on life satisfaction were significant. Second, the effects of discomfort in daily life and difficulty in motion performance in the elderly on depression were found to be at a statistically significant level. Third, the effect of depression on life satisfaction was found to be statistically significant. Fourth, the partial mediating effect of depression was examined in the relationship between the daily life discomfort and difficulty in motion performance of the elderly on life satisfaction. These results clarified that daily life discomfort, difficulty in performing movements, and depression should be reduced in order to improve life satisfaction of the elderly. Through this, a discussion was presented to increase the life satisfaction of the elderly.

• Korean Journal of Community Nutrition
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• v.27 no.5
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• pp.406-421
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• 2022

Objectives: The purpose of this study was to investigate the blood biochemical characteristics, comorbidities, dietary intake, and other risk factors leading to poor glycated hemoglobin (HbA1c) control in elderly Korean diabetes patients over 65 years of age. Methods: Data from the 4^th (2007-2009) and the 7^th (2016-2018) Korea National Health and Nutrition Examination Surveys (KNHANES) were used. Socio-demographic characteristics (age, gender, region, household income, education level, marital status, nutrition education, diabetes duration and diabetes treatment), lifestyle characteristics (drinking, smoking, regular walking, and subjective health perception), anthropometric characteristics (height, weight, and waist circumference), blood biochemical characteristics (HbA1c, high- density lipoprotein cholesterol, triglycerides, total cholesterol, blood urea nitrogen, and blood creatinine), co-morbidities (obesity, hypertension, hypercholesterolemia, hypertriglyceridemia, and anemia), energy and nutrients intake, food group intake, and HbA1c control-related risk factors were compared. Results: Compared to the 4^th survey, the 7^th survey showed an increase in diabetes prevalence among men, an increase in the prevalence of diabetes in the older patients, and an increase in the duration of diabetes. The energy ratio from carbohydrate consumption in the 7^th survey was lower than in the 4^th. Compared to the 4^th survey, thiamine and riboflavin intake had improved, and the intakes of vitamin A, vitamin C, and niacin had worsened in the 7^th. A comparison of food group intakes showed that there was a decrease in the consumption of whole grains, potatoes, and milk and an increase in the intake of beverages and alcoholic beverages. The risk factors for poor control of HbA1c were the duration of diabetes and co-morbid hypertriglyceridemia in the 4^th survey, whereas subjective health perception, obesity, and hypercholesterolemia as co-morbidities were found to be risk factors in the 7^th in addition to the risk factors highlighted in the 4^th survey. Conclusions: For the future management of elderly Korean diabetes patients, greater care is indicated for men over 75 years, and those with low levels of education. It is necessary to increase the intake of milk and vegetables, and reduce the intake of beverages and alcoholic beverages. In addition, it is necessary to reduce the incidence of obesity, hypercholesterolemia, and hypertriglyceridemia for proper control of blood sugar.