• Journal of the Korean GEO-environmental Society
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• v.22 no.2
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• pp.15-23
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• 2021

A method of improving the post-management end system of a landfill that reflected total pollutant load was applied to the SUDOKWON 1st Landfill Site. Modeling results showed that the ratio of remaining methane, when compared to the total maximum potential of 2,521 × 106 Nm3, was estimated to be 8.8% in 2020, 7.0% in 2030, and 6.5% in 2040. If the average oxidation rate of 89.1% in 2005-2019 was applied, the ratio decreased by 1.01% in 2020, 0.76% in 2030, and 0.70% in 2040. This suggests that if the amount of methane generated is all emitted from the surface of the landfill after 2025, the real amount emitted to the atmosphere is less than that in 2019; therefore, the post-management end is possible. According to the results of trend analysis of the quality of leachate water, effluent criteria for Biochemical Oxygen Demand (BOD) can be satisfied in 2024, while those for Chemical Oxygen Demand (COD) and Total Nitrogen (T-N) can be satisfied in 2047 and 2117, respectively. If the post-management end system changed based on total pollutant load, the post-management can be terminated BOD today and COD within a few years; however, the fact that T-N could be terminated only after 2041 shows the need to fundamentally change management methods.

• Journal of Digital Convergence
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• v.19 no.1
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• pp.29-43
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• 2021

Coinciding with the advent of COVID-19, online education is on the rise both domestically and globally, and has become an absolutely necessary and irreplaceable form of education. It is a very curious question what the perception of people about the suddenly growing form of education is, and how it has changed. This study investigated changes in consumers' perception of online education using big data. To this end, we divided the time into four stages: before COVID-19 (November to December 2019), after the triggering of COVID-19 (January to February 2020), right after the online classes started (March to April 2020), after experiencing some online education (May to June 2020). Then we conducted text mining, namely, keyword frequency analysis, network analysis, word cloud analysis, and sentiment analysis were performed. The implications derived as a result of the analysis can help education policy makers and educators working in the field to improve online education quality and establish its future directions.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.1
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• pp.126-137
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• 2021

Recently, the number of damages on social infrastructure has increased due to natural disasters and the frequency of earthquake events that are higher than magnitude 3 has increased in South Korea. Liquefaction was found near the epicenter of a 5.4 magnitude earthquake that occurred in Pohang, South Korea, in 2017. To explore increases in soil moisture index due to soil liquefaction, changes in the remote exploration index by the land cover before and post-earthquake occurrence were analyzed using liquefaction feasibility index and multi-cyclical Landsat-8 satellite images. We found that the soil moisture index(SMI) in the liquefaction region immediately after the earthquake event increased significantly using the Normal Vegetation Index(NDVI) and Surface Temperature(LST).

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.607-617
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• 2020

Human bio-monitoring (HBM) data is a very important resource for tracking total exposure and concentrations of a parent chemical or its metabolites in human biomarkers. However, until now, it was difficult to execute the integration of different types of HBM data due to incompatibility problems caused by gaps in study design, chemical description and coding system between different sources in Korea. In this study, we presented a standardized code system and HBM knowledge model (KM) based on relational database modeling methodology. For this purpose, we used 11 raw datasets collected from the Ministry of Food and Drug Safety (MFDS) between 2006 and 2018. We then constructed the HBM database (DB) using a total of 205,491 concentration-related data points for 18,870 participants and 86 chemicals. In addition, we developed a summary report-type statistical analysis program to verify the inputted HBM datasets. This study will contribute to promoting the sustainable creation and versatile utilization of big-data for HBM results at the MFDS.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.795-814
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• 2021

With the development of science and technology in recent years, various types of unstructured buildings have begun to be implemented by combining traditional architectural styles with digital tools, which are significantly different from conventional formal buildings. Designers will use various methods or digital tools to complete the unstructured and freer architectural forms when building an unstructured building. Based on this background, the need for research on the criteria for evaluating the characteristics of unstructured architectural forms is raised. First, the text was reconstructed by considering and integrating the elements of the unstructured exterior form based on prior research, with the external form of the unstructured building as the main research object. Second, the purpose of this study was to classify various types of unstructured forms and to provide important basic data for designing digital processes of unstructured architectural forms.Third, from 2000 to 2020, the text focused on the study of unstructured buildings and conducted in-depth analysis of the characteristics of their form expressions. While providing a case basis for the study of related fields, distribution laws and presence values related to the characteristics of unstructured buildings were sought. In addition, the analysis was conducted in combination with the distribution of functional use of buildings, and this study is differentiated from the existing research in that the atypical form is applied to the buildings by use, and the application trend of this type is understood to enhance understanding of the atypical form of buildings.

• Journal of Environmental Impact Assessment
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• v.30 no.4
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• pp.258-269
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• 2021

The purpose of this study is to establish a system to evaluate the ecological soundness of the Geum river basin. The study target area is 14 sub-watersheds of the Geum river basin. For the selection of indicators to ensure transparency and consistency of the evaluation indicators, the ecological soundness indicators were secured by using the indicator adjustment method derived in consideration of the intrinsic weight change characteristics between indicators. The index with the greatest impact on the final composite index was identified as the index of the aquatic ecology among the water quantity, water quality, aquatic ecology, and habitat-riparian environment dimensions. As a result of analyzing the ecological health index of the river, the watershed upstream of the dam (based on the Daecheong -dam) was evaluated to be in relatively good condition until 2014 compared to the base year(2008), and the watershed downstream of the dam was evaluated to be in a poor condition. The annual trend of changes in the ecological soundness index on an annual basis is as follows. In the case of Yongdamdam, Yongdamdamdownstream, Bocheong-chun, Daechungdam, Daechungdamdownstream, and Nonsancheon, although there are differences by time period, the soundness index is in declining. On the other hand, Mujunamdaecheon, Yeongdongcheon, and Gapcheon were evaluated to have improved soundness, while Chogang, Daechungdamupstream, Mihocheon, Gongjugeumgang, and Geumgangestuary were evaluated to deteriorate again after soundness was improved.

• Korean Journal of Construction Engineering and Management
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• v.23 no.2
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• pp.16-23
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• 2022

This study examined the trend of international competitiveness over the past 10 years (2011-2020), focusing on comparative analysis with China and the United States, targeting seven major export items of Korean construction machinery based on 6 units of HS code. To this end, the export similarity index and trade competitiveness index were calculated and analyzed using UN Comtrade and Korea International Trade Association trade statistics. As a result of the analysis, competition between Korea and China has intensified over the past decade, and competition with the United States has remained at a certain level. Korean forklifts (8427.20) are exporting to the world with strong competitiveness in the global market. Excavators (8429.52) and loaders (8429.51), which have the largest export share of Korean construction machinery, have a weight advantage, but they are exporting due to price inferiority. The rest of the items were found to be inferior in price and weight, and were not competitive in the global market. These analysis results suggest the following implications. First, it is necessary to strengthen efforts to expand exports of universal construction machinery items, which are expected to increase in demand in the future, by boosting the economy and expanding infrastructure investment in accordance with eco-friendly policies. Second, excavators, which have been shown to have a quality advantage and a price competitive advantage, need to further strengthen export marketing activities not only in China and the United States but also in emerging developing countries.

• Journal of Korea Water Resources Association
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• v.55 no.3
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• pp.245-255
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• 2022

Evaluating the qualitative the qualitative process of water resources by using various indicators, as one of the most prevalent methods for optimal managing of water bodies, is necessary for having one regular plan for protection of water quality. In this study, zoning maps were developed on a yearly basis by collecting and reviewing the process, validating, and performing statistical tests on qualitative parameters҆ data of the Iranian aquifers from 1995 to 2020 using Geographic Information System (GIS), and based on Inverse Distance Weighting (IDW), Radial Basic Function (RBF), and Global Polynomial Interpolation (GPI) methods and Kriging and Co-Kriging techniques in three types including simple, ordinary, and universal. Then, minimum uncertainty and zoning error in addition to proximity for ASE and RMSE amount, was selected as the optimum model. Afterwards, the selected model was zoned by using Scholar and Wilcox. General evaluation of groundwater situation of Iran, revealed that 59.70 and 39.86% of the resources are classified into the class of unsuitable for agricultural and drinking purposes, respectively indicating the crisis of groundwater quality in Iran. Finally, for validating the extracted results, spatial changes in water quality were evaluated using the Groundwater Quality Index (GWQI), indicating high sensitivity of aquifers to small quantitative changes in water level in addition to severe shortage of groundwater reserves in Iran.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.6
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• pp.119-133
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• 2021

Research has been conducted in many fields to identify research trends using text mining, but in the field of emotional labor, no research has been conducted using text mining to identify research trends. This study uses text mining to deeply analyze 1,465 papers at the Korea Citation Index (KCI) from 2004 to 2019 containing the subject word 'emotional labor' to understand the trend of emotional labor researches. Topics were extracted by LDA analysis, and IDM analysis was performed to confirm the proportion and similarity of the topics. Through these methods, an integrated analysis of topics was conducted considering the usefulness of topics with high similarity. The research topics are divided into 11 categories in descending order: stress of emotional labor (12.2%), emotional labor and social support (12.0%), customer service workers' emotional labor (10.9%), emotional labor and resilience (10.2%), emotional labor strategy (9.2%), call center counselor's emotional labor (9.1%), results of emotional labor (9.0%), emotional labor and job exhaustion (7.9%), emotional intelligence (7.1%), preliminary care service workers' emotional labor (6.6%), emotional labor and organizational culture (5.9%). Through topic modeling and trend analysis, the research trend of emotional labor and the academic progress are analyzed to present the direction of emotional labor research, and it is expected that a practical strategy for emotional labor can be established.

• Journal of Navigation and Port Research
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• v.46 no.3
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• pp.251-258
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• 2022

Donghae Port is adjacently located to a residential area wherein 26,933 generations are creating a living environment. The areas comprise Song-jeong village (5,754 generations) and Bukp-yeong village (21,179 generations). Major cargoes handled in Donghae Port are dusty limestone, cement, anthracite, and bituminous coal, etc. In the process of handling such cargoes, air pollutants including oxide dust and fine dust which adversely impact the living conditions and health of residents are generated, causing air pollution in the vicinity of the port. Currently, Donghae Port is making an effort to improve the operation environment of the infrastructure and equipment in stages, for the purpose of reducing air pollutant emissions caused by the port industries in a long-term perspective. In this study, the sphere of influence of fine dust exposure and the degree of air pollution in the surrounding area were analyzed such as the state of fine dust concentration and diffusion in the vicinity of Donghae Port, fine dust diffusion pattern and spatial distribution of high-concentration considering wind direction and speed characteristics during the day and seasonal cycles. A more effective plan to reduce the concentration of fine dust in nearby areas by combining reduction plan, is being developed in terms of improvement regarding port infrastructure and equipment, and reduction measures considering the characteristics of the atmosphere environment according to the daytime, nighttime and season.