• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.265-265
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• 2021

해수면 상승과 연안지역의 무분별한 지하수의 이용으로 해수침투는 가속화되고 있다. 해수면 상승과 지하수의 과잉 양수로 인한 연안지역의 대수층은 사용 가능한 담수 지하수자원이 줄어들고 있다. 연안지역의 대수층을 대상으로 해수 침투 영역에 미치는 영향에 대한 연구는 활발하게 진행되고 있다. GALDIT은 index & ranking 방법을 이용한 지하수자원의 해수침투에 대한 취약성 평가 방법으로 Geographic Information System (GIS)을 통해 주제도에 대한 중첩으로 평가 지수를 산정한다. 한국의 해수침투 취약성 평가에 대한 선행 연구 중 상당수는 제주도를 대상으로 많은 연구가 수행되었으며, GALDIT을 이용하여 해수침투에 대한 취약성 평가가 수행되었다. 본 연구에서는 내륙의 연안지역을 대상으로 GALDIT을 적용하였다. 한국의 서해안 지역 중 도심지가 밀집되어 있는 북쪽으로 선택하였다. 연구지역은 인천, 아산, 안산, 김포, 화성, 시흥, 평택, 당진, 오산으로 9개의 행정구역으로 구성되어 있다. 9개의 지역은 모두 제조업이 발달되어 도시화가 가속화되고 있으며, 지속적인 인구의 유입이 진행되고 있다. GALDIT은 지속가능한 해안지하수를 위한 수자원 계획을 뒷받침하는 평가 자료로 사용될 수 있으며, 국내 기후 및 공간 특성 매개변수를 고려한 가중치 및 평가 기준의 확대 등이 필요할 것으로 생각된다.

• Journal of the Korean Regional Science Association
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• v.37 no.4
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• pp.33-47
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• 2021

In urban declining areas, the population is decreasing, and drying environments such as buildings and facilities are aging. Therefore, it is vulnerable in the event of disaster, and recovery takes a lot of time and money. The purpose of this study is to develop an evaluation technique for comprehensively diagnosing disasters in declining areas and to present implications through case analysis. Evaluation indicators were selected to calculate the comprehensive diagnosis index of disasters, and weights were calculated for each class, including disaster types, components, and evaluation indicators, through Analytic Hierarchy Process analysis. The comprehensive diagnoses index for each type of disaster was calculated with the calculated weight, and the risk according to the level of urban decline was analyzed. As a result of analyzing Seoul as a case area, it was analyzed that the overall risk of disasters was high in southern regions such as Seocho-gu, Dongjak-gu, Geumcheon-gu, and Gangseo-gu, and relatively low in downtown and northern Seoul, parks and green areas. The results of this study are of academic significance in that they presented a comprehensive diagnostic index evaluation system and technique for each type of disaster, including natural and social disasters.

• Tunnel and Underground Space
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• v.33 no.6
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• pp.594-609
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• 2023

TBM (Tunnel Boring Machine) method is gaining popularity in urban and underwater tunneling projects due to its ability to ensure excavation face stability and minimize environmental impact. Among the prominent models for predicting disc cutter life, the NTNU model uses the Cutter Life Index(CLI) as a key parameter, but the complexity of testing procedures and rarity of equipment make measurement challenging. In this study, CLI was predicted using multiple linear regression analysis and tree-based machine learning techniques, utilizing rock properties. Through literature review, a database including rock uniaxial compressive strength, Brazilian tensile strength, equivalent quartz content, and Cerchar abrasivity index was built, and derived variables were added. The multiple linear regression analysis selected input variables based on statistical significance and multicollinearity, while the machine learning prediction model chose variables based on their importance. Dividing the data into 80% for training and 20% for testing, a comparative analysis of the predictive performance was conducted, and XGBoost was identified as the optimal model. The validity of the multiple linear regression and XGBoost models derived in this study was confirmed by comparing their predictive performance with prior research.

• Analytical Science and Technology
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• v.23 no.4
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• pp.347-356
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• 2010

Emission characteristics of major offensive odorants were investigated using odor samples collected from two urban stormwater catch basins with highly contrasting environmental conditions. A total of 6 major offensive odorants ($H_2S$, $CH_3SH$, DMS, DMDS, $CH_3CHO$ (AA), and $NH_3$) were measured. For this comparative analysis, odor intensity (OI) of all odorants was derived from their concentration data via empirical equations introduced by Nagata. Both the absolute magnitude of odorant concentrations and their OI values were used concurrently to evaluate the occurrence pattern of each individual odorant. According to our analysis, RSCs including $CH_3SH$, $H_2S$, and DMS tend to exhibit the highest odor strengths among all 6 compounds investigated. The overall results of our study suggest that the emissions of major offensive odorants from urban stormwater catch brains can be explained at least partially by the temporal trend of human activity.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.189-200
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• 2023

As urbanization and industrialization increase development in downtown areas, damage due to ground settlement continues to occur. Building collapse in urban has a high risk of leading to large-scale damage to life and property. However, there has rarely been studied on measurement data analysis methods when uneven loads are applied to the excavated ground and no prior knowledge of the ground. Accordingly, it was attempted to analyze the relative settlement behavior and correlation by processing the time-series surface settlement of construction sites in the urban. In this paper, the average index of difference in settlement and average of relative difference in settlement are defined and calculated, then plotted in the coordinate system to analyze the relative settlement behavior over time. In addition, since there was no prior knowledge of the ground, a standard to classify the clusters was needed, and the observation points were classified into using k-means clustering and Dunn Index. As a result of the analysis, it was confirmed that all the clusters moved to the stable region as the settlement amount converges. The clusters were segmented. Based on the analysis results, it was possible to distinguish between the independent displacement area and same behavior area by analyzing the correlation between measurement points. If possible to analyze the relative settlement behavior between the stations and classify the behavior areas, it can be helpful in settlement and stability management, such as uplift of the surrounding area, prediction of ground failure area, and prevention of activity failure.

• Journal of Korea Water Resources Association
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• v.49 no.4
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• pp.305-314
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• 2016

In this study, a quantitative assessment was carried out in order to identify the agricultural drought in time and space using the Terra MODIS remote sensing data for the agricultural drought. The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) were selected by MOD13A3 image which shows the changes in vegetation conditions. The land cover classification was made to show only vegetation excluding water and urbanized areas in order to collect the land information efficiently by Type1 of MCD12Q1 images. NDVI and EVI index calculated using land cover classification indicates the strong seasonal tendency. Therefore, standardized Vegetation Stress Index Anomaly (VSIA) of EVI were used to estimated the medium-scale regions in Korea during the extreme drought year 2001. In addition, the agricultural drought damages were investigated in the country's past, and it was calculated based on the Standardized Precipitation Index (SPI) using the data of the ground stations. The VSIA were compared with SPI based on historical drought in Korea and application for drought assessment was made by temporal and spatial correlation analysis to diagnose the properties of agricultural droughts in Korea.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.5
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• pp.451-457
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• 2014

Recently, the land degradation and pasture erosion in Tuv, located around Ulaanbaatar of Mongolia, have been increasing sharply due to escalating developments of mining sectors, well as the density of populations. Because of that, we have chosen the urban and mining area of Tuv for our study target. During the study, the temporal changes of land cover in Tuv, Mongolia were observed by the Landsat TM/+ETM satellite images from 2001 to 2009 that provided the fundamental dataset to apply NDVI and K-Mean algorithm of Unsupervised Classification and Maximum likelihood classification(MLC) of Supervised Classification in order to conclude in land cover change analyzation. The result of our study implies that the growth of mining area, the climate change, and the density of population led the land degradation to desertification.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.288-288
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• 2019

지구온난화로 인해 해수면이 지속적으로 상승하고 있으며, 이에 따라 연안인근 지역은 복합원인에 의한 홍수피해가 빈번히 발생하고 있다. 우리나라는 반도 지형으로 해수면 상승에 따라 침수피해 발생 시 피해규모가 클 것으로 예상되어 이에 적극적으로 대처할 필요가 있다. 복합원인에 의한 침수예상도는 해수위를 고려한 내외수 침수피해 발생 시 침수의 범위 및 양상을 예측한다. 먼저 침수발생 시 피해규모가 클 것으로 예상되는 연안인근의 도심지역을 위주로 대상지역을 선정하였으며, 침수발생 원인별 침수예상도를 작성하였다. 작성된 침수예상도를 바탕으로 상세 홍수취약성을 평가하였으며, 이를 바탕으로 주요 시설물의 위치 선정, 관거 개량의 우선순위 선정 등에 활용할 수 있다. 먼저 도상조사를 통해 침수발생 후보지역을 선정하고, 현장답사를 통해 현장 변경사항, 재해원인 및 재해발생가능성을 검토하여 대상지역으로 여수시 연등천 인근을 선정하였다. 모의 방법으로는 HEC-HMS 및 XP-SWMM 등 강우-유출 모형에 의해 침수해석을 실시하고, 하류단 경계조건의 변화에 따른 기점수위를 산정하여 해수위를 고려하였다. 하류단 경계조건으로는 대상지역의 폭풍해일에 의한 해수위 상승고를 적용하였다. 배수토구가 하천으로 연결된 경우에는 해당 하천의 홍수위 산정이 필요하며 홍수위 산정에는 HEC-RAS 모형을 사용하였다. 작성된 침수예상도를 통해 상세 홍수취약성 분석을 실시하였으며, 상세 홍수취약성 지수는 "기후변화 적응을 위한 연안도시지역별 복합원인의 홍수 취약성 평가기술 개발 및 대응방안 연구"에서 개발된 지표를 기반으로 산정하였다. 본 연구에서는 강우-유출 모형의 하류단 경계조건 변화를 통해 해수위 상승을 고려하여 연안도시 지역의 침수예상도를 작성하였으며, 침수발생 예상도를 통해 상세 홍수취약성을 분석하였다. 이는 침수발생에 따른 대피지도 개발, 주요 시설물의 계획, 침수피해 예방을 위한 구조적 대책 수립을 위한 기초자료로 활용될 수 있다.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.172-186
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• 2022

Benthic macroinvertebrates are important ecological and environmental indicators as primary or secondary consumers, and therefore are widely used in the evaluation of aquatic environments. However, there are no comprehensive river ecosystem monitoring surveys that link the major physicochemical water quality items with benthic macroinvertebrates in urban streams. Therefore, this study investigated the distribution characteristics of benthic macroinvertebrates and physicochemical water quality items (17 items) in Yangjaecheon and Yeouicheon from 2019 to 2020. At the same time, by applying Spearman's rank correlation analysis and nonmetric multidimensional scaling (nMDS) analysis in the water quality data and biotic index, we tried to provide basic data for diagnosing the current status of river ecosystems in major urban rivers in Seoul. Based on the study results, a total of 39 species and 3,787 individuals were identified in Yangjaecheon, the water quality(based on BOD, TOC, and TP) of Yangjaecheon was higher than Grade Ib(good), and the BMI using benthic macroinvertebrates appeared as Grade C(normal) at all the sites. In Yeouicheon, a total of 51 species and 4,199 individuals were identified, the water quality(based on BOD, TOC, TP) was higher than Grade Ib(good) similar to Yangjaecheon, and the BMI of both Upstream and Saewon bridge was Grade B(good), while Yeoui bridge was Grade C(normal). Overall, analysis results for the distribution of benthic macroinvertebrates by a nonmetric multidimensional scaling method showed no significant difference between the two streams (p=0.1491). Also, significant environmental variables related to benthic macroinvertebrates distribution were determined as water temperature and DO. On the other hand, the results of the correlation analysis between biotic index and major water quality items confirmed that R1 and BMI could be used for on-site urban river water quality evaluation.

• Research in Community and Public Health Nursing
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• v.9 no.1
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• pp.223-231
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• 1998

결혼한 여성의 우울과 관련된 주 요인의 하나는 그들의 다양한 역할이 정신적인 건강에 부정적인 영향을 심리적으로 미친다고 발표되어 있다. 그럼에도 불구하고 한국 이민 주부에 대한 이러한 영역에서의 연구가 매우 부족한 실정이다. 중서부의 주요 도시인 시키고의 도심지에 위치한 11곳의 한국인 교회에서 편의 표출 방법으로 다음과 같은 기준에 맞는 대상자를 선택하였다. 나이는 25-55세 사이, 결혼하여 남편과 함께 살고 있으며, 매주 20시간 이상씩 일하고 있는 여성 등의 기준을 충족시키는 응답자의 수는 282명이었다 대상자들에게는 5가지의 설문 즉 인구통계학적, 우울에 대한 역학 연구, 성 역할 지향성의 지수, 역할 분담 및 대처 전략 등에 관한 질문이었다. 중다회귀분석 (Multiple Regression Analysis)에서 통계학적으로 유의한 관계를 보인 것은 다음과 같았다. 주부의 자녀가 적을수록 우울의 수준은 높았고, 가족의 수입이 많을수록 우울의 수준은 낮았으며, 주부가 일하는 것이 경제적 필요를 충족시키기 위함이라고 스스로 지각(주부들은 일하는 역할이 합법적으로 판단되어지기를 원했고 또 지각했는데 이와 대조하여 일의 역할을 비합법적으로 지각하는 것)할수록 우울의 수준은 더 높았다. 비록 일하는 것이 저녁 늦게 자고 아침 일찍 일어남을 의미할지라도 모든 가사를 완수하기 위하여 열심히 일한다고 하면 할수록 우울의 수준은 더 높았다. 주부가 일의 역할을 합법적으로 지각하면 할수록 남편과 다른 가족의 구성원들에게 도움을 요청하거나 도움을 받는 것을 원하지 않았으며, 일을 더 열심히 하기 위해 대처전략과 우선순위(주부가 일을 전혀 완수 할 수 없을지라도 가정의 어떤 일이 중요하고 어느 것이 두 번째로 중요한지를 결정하는)를 더 잘 설정하고 더 잘 수용하는 것 같았다. 식품 등을 쇼핑하는데에 많은 시간을 소모할수록 우울의 수준은 더 높았다. 이 자료는 스트레스와 대처이론을 지지하고 있다.