• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.213-213
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• 2020

최근 나타나는 지구온난화와 이상기후로 인해 가뭄과 홍수피해 같은 자연재해 발생 빈도가 높아졌고, 하천에서는 오염된 수질과 수생태계 복원 및 수변공간 조성, 수자원 관리 등의 목적으로 수질환경 개선사업이 진행되고 있다. 수질환경 측면에서 하천에서 발생하는 가장 큰 문제점으로는 녹조 즉, 남조류의 발생을 예로 들 수 있다. 본 연구에서는 최근 보 개방을 통하여 수질개선 효과가 나타나고 있는 금강을 대상으로 세종보, 공주보, 백제보 구간에 대하여 주요 수질인자에 대한 상관관계 분석을 수행하였다. 특히 남조류 세포수와 주요 하천 수질인자를 Pearson's correlation analysis를 이용하여 상관관계를 분석하였고, 보 위치별 남조류 세포수를 종속변수로 하고, 상관도가 높은 수질인자를 독립변수로 하는 다중회귀식을 도출하여 금강 내 주요 하천 수질인자의 농도에 따른 남조류 세포수 관계를 규명하고자 하였다. 분석기간은 2012년 1월부터 2019년 12월까지 보 건설 이후 시점으로 선정하였고, 월 평균 남조류 개체수가 조류경보제 발령기준 관심단계이상에 해당하는 금강수계의 3개 보에 대하여 남조류 세포수와 수질에 영향을 끼치는 인자인 강수량, (수온)W·T, (수소이온농도)pH, (용존산소)DO, (생물화학적산소요구량)BOD, (화학적산소요구량)COD, (부유물질량)SS, (총질소)TN, (총인)TP, (클로로필-a)Chl-a, (전기전도도)EC, (질산성질소)NO₃-N, (암모니아성 질소)NH₃-N, (인산염 인)PO₄-P, (용존총질소)DTN, (용존총인)DTP, (총유기탄소)TOC 와의 상관관계를 분석하였다. 분석 결과 측정 지점별 남조류 세포수와 상관관계가 있는 인자는 서로 상이했지만 (수온)W·T과 pH의 경우 모든 지점에서 남조류 세포수와 양의 상관관계가 나타났다. 세종보는 W·T(0.383, P<0.01), pH(0.391, P<0.05)의 양의 상관계수를 나타냈고, 공주보에서는 (수온)W·T(0.436, P<0.05), pH(0.412, P<0.05)의 양의 상관관계를 나타냈다. 백제보에서는 (수온)W·T(0.415, P<0.01), pH(0.221, P<0.01)의 양의 상관성을 나타냈다. 남조류 세포수와 수질인자 간의 상관관계 분석에 따라 통계적으로 유의한 인자 중 (수온)W·T과 pH에 영향을 받는 영양염류와 퇴적물에 대한 후속 연구가 필요할 것으로 사료되며, 연구를 통해 제시된 남조류 세포수 다중회귀식은 주요 수질인자 농도에 따라 발생 가능한 남조류세포수를 예측하여 금강의 수질 관리에 활용될 수 있을 것으로 기대된다.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.457-465
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• 2023

This study was carried out in order to determine the essential structure and meaning of sexual harassment experienced by nurses, prepare a systematic mediation measure that could prevent sexual harassment. In this study, Giorgi's phenomenological research method and an in-depth interview were used, and data was collected from seven participants in general hospital nurses who had experienced sexual harassment from August 6, 2022 to March 25, 2023. The main question used in the in-depth interview was "What does sexual harassment mean to you?". The transcribed data was analyzed according to the method presented by Giorgi through the stages including reading of the data, breaking of the data into some kind of parts, organization and expression of the data from a disciplinary perspective and synthesis or summary of the data for purposes of communication to the scholarly community. As a result, 159 meaning units, 37 essential psychological meanings, 13 sub-constituents, 5 constituents were drawn. The five components include 'exposed to the front line of sexual harassment', 'struggling alone', 'feeling abandoned from the organization', 'finding a way to get through together' and 'feeling changing'. Based on the above results, it is expected to prevent sexual harassment of nurses and provide basic data useful for preparing systematic intervention measures for them and improving the system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.169-177
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• 2010

Recently due to the typhoon and extreme rainfall induced by abnormal weather and climate change, the probability of severe damage to human life and property is rapidly increasing. Thus it is necessary to create adequate and reliable flood risk map in preparation for those natural disasters. The study area is Seo-gu in Daegu which is located near Geumho river, one of the tributaries of Nakdong river. Inundation depth and velocity at each time were calculated by applying FLUMEN model to the target area of interest, Seo-gu in Daegu. And the research of creating flood risk map was conducted according to the Downstream Hazard Classification Guidelines of USBR. The 2-dimensional inundation analysis for channels and protected lowland with FLUMEN model was carried out with the basic assumption that there's no levee failure against 100 year precipatation and inflow comes only through the overflowing to the protected lowland. The occurrence of overflowing was identified at the levee of Bisan-dong located in Geumho watershed. The level of risk was displayed for house/building residents, drivers and pedestrians using information about depth and velocity of each node computed from the inundation analysis. Once inundation depth map and flood risk map for each region is created with this research method, emergency action guidelines for residents can be systemized and it would be very useful in establishing specified emergency evacuation plans in case of levee failure and overflowing resulting from a flood.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2B
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• pp.173-179
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• 2009

Industrial water supplied by water resource project is essential input materials along with labor, capital and land for companies. It is very important to stably secure these input materials in order for the industry to generate additional values. If the supply of industrial water is stopped, it is known damage for the industry is greater than domestic water or agriculture water based on same amount of supply. Like this, the actual value of industrial water has been highly acknowledged from the intuitive perspective, but study on the value and benefits of industrial water has been rarely conducted. Therefore, this study verified the value of industrial water supplied from water resource project, and used marginal production value as a measure to estimate the benefits of industrial water in the analysis of economic efficiency. As a result of empirical analysis using Cobb-Douglas production function and Translog production function, industries' average marginal production value was $5,427KRW/m^3$ and $5,583KRW/m^3$ respectively. The marginal production value for eleven industries were estimated by using same method. The marginal production value by industries presented by this study will be used as important data to calculate benefits of industrial water in the future. Moreover, the result of this study will provide reasonable criteria for decision making on the allocation of water in emergency situation, and problem of resource supply from water resource project.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.351-360
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• 2010

In 2010, the number of registered vehicles reached almost at 17.48 millions in Korea. This dramatic increase of vehicles influenced to increase the number of traffic accidents which is one of the serious social problems and also to soar the personal and economic losses in Korea. Through this research, an enhanced intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network will be developed in order to obtain the important data for developing the countermeasures of traffic accidents and eventually to reduce the traffic accidents in Korea. Firstly, this research has investigated the influencing factors of road geometric features on the traffic volume of each approaching for the intersections where traffic accidents and congestions frequently take place and, a linear regression model of traffic accidents and traffic conflicts were developed by examining the relationship between traffic accidents and traffic conflicts through the statistical significance tests. Secondly, this research also developed an intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network through applying the intersection traffic volume, the road geometric features and the specific variables of traffic conflicts. Lastly, this research found out that the developed model is better than the existed forecasting models in terms of the reliability and accuracy by comparing the actual number of traffic accidents and the predicted number of accidents from the developed model. In conclusion, it is expect that the cost/effectiveness of any traffic safety improvement projects can be maximized if this developed intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network use practically at field in the future.

• Smart Media Journal
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• v.11 no.7
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• pp.9-18
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• 2022

With the outbreak of COVID-19, the world is in unexpected chaos. In particular, the Korean economy, which has a large number of self-employed people, is experiencing enormous damage from COVID-19. The purpose of this study is to analyze the causal impact of start-ups and closures by industry due to the COVID-19 outbreak. For the causal impact analysis, we collected and analyzed 8,312,224 cases of start-up and closure of 190 businesses that occurred on the local administrative license data public site for 11 years from 2010 to 2020. As a result of the analysis of the causal impact of COVID-19, there were 29 industries in which start-ups increased(increase rate 313.14% ~ 6.39%), 23 industries in which start-ups decreased(decrease rate 70.62% ~ 11.27%), 21 industries in which closures increased(increase rate 157.55% ~ 13.57%), and 18 industries in which business closures decreased(reduction rate 49.45% ~ 12.91%). The industries in which start-ups increased and closures decreased due to the COVID-19 outbreak were disinfection, food transportation, and general sales of health functional food. The industries in where start-ups decreased and closures increased due to the COVID-19 outbreak were youth game providing industry, danran pub business, and general game providing industry. It is expected that the results of this study will help practitioners who manage various infectious diseases to understand the causal impact of infectious disease outbreaks and to prepare countermeasures.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.379-385
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• 2023

EDue to climate change and urbanization, the localized heavy rainfall frequently exceeded a design storm rainfall and flood damage has occurred in South Korea. The concept of addressing sustainable river management and environmental and social issues through Nature-based Solutions (NbS) is gaining attention as it seeks to resolve these issues through ecosystem services. Therefore, in this study, the flood reduction effect by river management using NbS was quantitatively analyzed for the Hwang River, which is directly downstream of Hapcheon Dam, South Korea. Floodplain excavation and dyke relocation, which are methods of the NbS, were applied to the flood risk area of the Hwang River. As a result of analyzing the flood level of the river through the unsteady flow analysis of HEC-RAS, we obtained flood level reduction by 8 cm at the confluence of the Nakdong River. The results of this study can be expected to be sufficiently utilized as a basis for use as a management plan through NbS rather than the river management with grey infrastructure.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.826-833
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• 2023

Purpose: We suggest the need to utilize ESG in the safety field to prevent serious industrial accidents. Method: The Serious Accident Punishment Act, a strong serious accident prevention system, was reviewed through a review of previous research. And through comparative analysis of serious accident data from the United States and Korea, the main causes of accidents in the domestic chemical industry were derived. Result: It was determined that there was a need to induce voluntary safety management by companies through ESG management along with the Serious Accident Punishment Act, which aims to prevent corporate accidents. Through statistical analysis of accident data, it was confirmed that the scale of damage and number of deaths in domestic accidents was greater than in the United States. The reason was interpreted to be that there are many accidents caused by human causes in the country. Conclusion: In order to compensate for the lack of voluntariness in corporate safety management as well as the Serious Accident Punishment Act and encourage active safety management, the proportion of 'ESG safety evaluation' must be expanded. By using ESG as an indirect social sanction, we can expect companies to voluntarily and actively manage safety and expand safety investments in the safety field.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.859-873
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• 2023

Wildfires cause a lot of environmental and economic damage to the Earth over time. Various experiments have examined the harmful effects of wildfires. Also, studies for detecting wildfires and pollutant emissions using satellite remote sensing have been conducted for many years. The wildfire product for the Geostationary Environmental Monitoring Spectrometer (GEMS), Korea's first environmental satellite sensor, has not been provided yet. In this study, a false-color composite for better expression of wildfire smoke was created from GEMS and used in a U-Net model for wildfire detection. Then, a classification model was constructed to distinguish yellow dust from the wildfire smoke candidate pixels. The proposed method can contribute to disaster monitoring using GEMS images.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.5
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• pp.40-48
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• 2023

In this paper, a sensor-based monitoring system was established to analyze the long-term behavioral characteristics of the caisson quay wall, a representative structural type in port facilities. Data was collected over a period of approximately 10 months. Based on existing literature, anomalous behaviors of port facilities were classified, and a measurement system was selected to detect them. Monitoring systems were installed on-site to periodically collect data. The collected data was transmitted and stored on a server through LTE network. Considering the site conditions, inclinometers for measuring slope and crack meters for measuring spacing and settlement were installed. They were attached to two caissons for comparison between different caissons. The correlation among measured data, temperature, and tidal level was examined. The temperature dominated the spacing and settlement data. When the temperature changed by approximately 50 degrees, the spacing changed by 10 mm, the settlement by 2 mm, and the slope by 0.1 degrees. On the other hand, there was no clear relationship with tidal level, indicating a need for more in-depth analysis in the future. Based on the characteristics of these collected database, it will be possible to develop algorithms for detecting abnormal states in gravity-type quay walls. The acquisition and analysis of long-term data enable to evaluate the safety and usability of structures in the event of disasters and emergencies.