• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.571-581
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• 2020

Vegetation affects water level change and flow resistance in rivers and impacts waterway ecosystems as a whole. Therefore, it is important to have accurate information about the species, shape, and size of any river vegetation. However, it is not easy to collect full vegetation data on-site, so recent studies have attempted to obtain large amounts of vegetation data using terrestrial laser scanning (TLS). Also, due to the complex shape of vegetation, it is not easy to obtain accurate information about the canopy area, and there are limitations due to a complex range of variables. Therefore, the physical structure of vegetation was analyzed in this study by reconfiguring high-resolution point cloud data collected through 3-dimensional terrestrial laser scanning (3D TLS) in a voxel. Each physical structure was analyzed under three different conditions: a simple vegetation formation without leaves, a complete formation with leaves, and a patch-scale vegetation formation. In the raw data, the outlier and unnecessary data were filtered and removed by Statistical Outlier Removal (SOR), resulting in 17%, 26%, and 25% of data being removed, respectively. Also, vegetation volume by voxel size was reconfigured from post-processed point clouds and compared with vegetation volume; the analysis showed that the margin of error was 8%, 25%, and 63% for each condition, respectively. The larger the size of the target sample, the larger the error. The vegetation surface looked visually similar when resizing the voxel; however, the volume of the entire vegetation was susceptible to error.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.771-779
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• 2020

This study was performed to develop a priority list for post-managements of leachates from 64 mine waste dump sites in Korea. For this, leachate quality, leachate quantity, and other factors were considered as evaluation criteria and the weights of 10 subfactors were calculated using Analytic Hierarchical Process (AHP) based on a survey from 20 experts in the field of mining environment. Calculated weights were 0.769, 0.147 and 0.084 for leachate quality, leachate quantity, and others, respectively, indicating that experts consider leachate quality as most important. Based on this approach, we classified the 64 mine waste dump sites into five grades from Grade I to Grade V. Ten were classified as Grade I, 1 as Grade II, 1 as Grade III, 33 as Grade IV, and 19 as Grade V.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.541-549
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• 2020

This study conducts differential analysis on the financial positions of Korean shipping companies before and after the bankruptcy of the H carrier, looking specifically at their financial ratios, profit and loss patterns, and other factors related to their financial operation. Firstly, it was discovered that major measures of financial health, such as average assets per carrier, were not affected by the bankruptcy of the H carrier. However, despite this, most carriers experienced large changes in profits and losses, with total sales and shipping revenues averaging 424.5 billion won and 381.7 billion won respectively before the bankruptcy, but falling by half to 252.1 billion won and 234.6 billion won after the bankruptcy. Additionally, charter revenues and expenses also dropped by more than half. EBIT/sales and pre-tax revenue margins were also heavily affected after the bankruptcy, with both figures averaging 8% and 3% respectively before the bankruptcy, but falling into the negative range at -2% and -8% post-bankruptcy, resulting in significant deterioration in operational profitability. The study concludes that there is an urgent need to establish a global sales network, improve cost structures, and consistently secure stable cargo in order to increase Korean carriers' profitability. Of all financial measures, liquidity and total asset efficiency were identified as the most severely-impacted by the H carrier bankruptcy, thereby requiring the most pressing policy addressing.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.975-980
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• 2020

Cervical neural foraminal stenosis is a very common spinal disease that affects a relatively large number of people of all ages. However, since imaging methods that quantitatively provide neural foraminal stenosis are lacking, this study attempts to present quantitative measurement results by reconstructing 3D computed tomography images. Using a 3D reconstruction software, the surrounding bones were removed, including the spinous process, transverse process, and lamina of the cervical spine so that the neural foramen were well observed. Using Image J, a region of interest including the neural foramen area of the 3D image was set, and the number of pixels of the neural foramen area was measured. The neural foramen area was calculated by multiplying the number of measured pixels by the pixel size. In order to measure the widest area of the neural foramen, it was measured between 40-50 degrees in the opposite direction and 15-20 degrees toward the head. The measured cervical neural foramen area showed consistent measurement values. The largest measured area of the right neural foramen C5-6 was 12.21 ㎟, and after 2 years, the area was measured to be 9.95 ㎟, indicating that 18% stenosis had progressed. Since 3D reconstruction using axial CT scan images, no additional radiation exposure is required, and the area of stenosis can be objectively presented. In addition, it is good to explain to patients with neural stenosis while viewing 3D images, and it is considered a good method to be used in the evaluation of the progression of stenosis and post-operative evaluation.

• Tunnel and Underground Space
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• v.30 no.6
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• pp.509-518
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• 2020

This study constructed a new simulation platform, including mesh generation process, numerical simulation, and post-processing for results analysis based on exploration data to perform real-scale numerical analysis considering the actual geological structure efficiently. To build the simulation platform, we applied for open-source programs. The source code is open to be available for code modification according to the researcher's needs and compatibility with various numerical simulation programs. First, a three-dimensional model(3D) is acquired based on the exploration data obtained using a drone. Then, the domain's mesh density was adjusted to an interpretable level using Blender, the free and open-source 3D creation suite. The next step is to create a 3D numerical model by creating a tetrahedral volume mesh inside the domain using Gmsh, a finite element mesh generation program. To use the mesh information obtained through Gmsh in a numerical simulation program, a converting process to conform to the program's mesh creation protocol is required. We applied a Python code for the procedure. After we completed the stability analysis, we have created various visualization of the study using ParaView, another open-source visualization and data analysis program. We successfully performed a preliminary stability analysis on the full-scale Dokdo model based on drone-acquired data to confirm the usefulness of the proposed platform. The proposed simulation platform in this study can be of various analysis processes in future research.

• Journal of Environmental Impact Assessment
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• v.29 no.6
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• pp.453-466
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• 2020

The addition and evaluation of health impact items in Environmental Impact Assessment document are written in hygiene and public health items only for specific development projects and are being reviewed. However, after the publication of the evaluation manual on the addition and evaluation of health impact items in 2011, there is a demand for continuous methodology and improvement plans despite partial improvement. Therefore, in order to propose a methodological improvement of the evaluation manual, this technical paper identified detailed improvement requirements based on the consultation opinions on hygiene and public health items, and investigated and suggested ways to solve this problem by reviewing the contents of the research so far. As for the improvement requirements, the contents related to mitigation plan, post management, effect prediction, assessment, and present-condition investigation were presented in Environmental Impact Assessment documents for the entire development project at a frequency of 93%, 85%, 80%, 74%, and 67%, respectively. Particularly, the detailed improvement requirements related to mitigation plan consisted of an establishment direction and a management of development project. Considering the current evaluation manual and the frequency of improvement requirements, this paper proposed concrete methods or improvement plans for major methodologies for each classification of hygiene and public health items. Furthermore, a comprehensive evaluation methodology related to whether a project is implemented was proposed, which is not provided in the current assessment manual.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.58-73
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• 2020

The purpose of this study is to empirically analyze the relationship between organizational commitment, job satisfaction, education and training, human resource development, and communication in Korea's financial industry. In particular, the mediating relationships between organizational commitment and job satisfaction, education and training, human resource development, and communication were examined in order to provide a better understanding of organizational commitment. A structural equation model was used for the empirical analysis of this study. As a result of the study, it was confirmed that education and training, human resource development, communication, organizational commitment, and job satisfaction are correlated within the Korean financial industry. Furthermore, organizational commitment was found to have mediating effects on education and training, human resource development, communication, and job satisfaction. Based on these results, this study emphasizes the importance of education and training for organizational commitment in the Korean financial industry. In particular, this study establishes the importance of a culture of trust within organizations through human resource development programs, communication for job satisfaction, and organizational performance to face changes in the post-COVID era. In the future, more in-depth qualitative studies are required to derive factors related to the employees of financial companies and to conduct comparison analyses with companies in other industries.

• Journal of Internet of Things and Convergence
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• v.7 no.2
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• pp.13-19
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• 2021

It is analyzed that the energy pattern is affected by the social matters of the disease trend where the energy consumption has been reduced following the depression of the national economy. The campaign of social distance for the people has been done by voluntary or legally due to the epidemic of the Coronavirus Disease 2019 (COVID-19). Some economic stimulus policies have been done in some countries including the United States, South Korea, and some others. It is shown the susceptible, infectious, and recovered (SIR) modeling applied by system dynamics (SD) where the logical modeling is constructed with S, I, and R. Especially, the I is connected with Society including Population, Race, and Maturity. In addition, Economy and Politics are connected to Income, GDP, Resources, President, Popularity, Ruling Government, and Leadership. The graph shows the big jump on 2020 April when is the starting month of the S value multiplication. This shows the effect of the COVID-19 and its related post-pandemic trend. The trends of OECD and non-OECD are very similar and the effect of the virus hazards causes significantly to the economic depressions.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.705-713
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• 2020

The present study investigated the temporal changes of river habitats caused by construction and operation of the three large weirs (Sejong, Gongju, and Baekje) in the Geum River. High resolution satellite imagery taken during three periods (preconstruction, before and after gate operation) were used for habitat analysis. We divided bar area into eight habitat types in addition to water area. Then, we identified the nine habitat types from the satellite imagery and estimated each habitat area. Our results show that after weir construction, large bar areas were dramatically decreased and bareland was nearly absent post gate-operation in all three weirs. However, total bar area and bareland were again increased distinctively soon after weir opening events, especially in the uppermost weir, the Sejongbo. These results suggest that weir opening operations provide a relatively simple channel of more diverse through the process of increasing bar area in a river channel.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.62-70
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• 2021

2020 was a year in which the world spent in disorder due to the pandemic of Coronavirus infection-19(COVID-19). The pandemic was at the beginning of a turning point in history. For examples, the Black Death(Pest) that destroyed the feudal system of medieval Europe in the 14th century, smallpox that led to the destruction of the Inca Empire by Spain in the 17th century, and the Spanish flu that ended World War I early. The great transformation that will come after COVID-19 is presented from various fields and perspectives, but the understanding and direction of the transformation is ambiguous. This study attempts to derive and to analyze core terms based on a network of the future of globalization after COVID-19. Four Networks related to globalization, anti-globalization, and globalization and digitalization after COVID-19 were established respectively. A network integrating four networks was also constructed. The core terms were extracted from the hub nodes, the stress centrality, and the simplified network to which the K-core algorithm was applied. After COVID-19, the changes in globalization were analyzed from the extracted core terms. This study is thought to be meaningful to propose a method of deriving and analyzing core terms based on a network in understanding social changes after COVID-19.