Inundation Analysis of Coastal Area Considering Climate Change

Kim, Kyungtae,Kim, Yonsoo,Kim, Soojun,Choi, Changhyun,Kim, Hung Soo 한국방재학회 2015 한국방재학회 학술발표대회논문집 Vol.14 No.-

Future climate change is expected to raise the mean sea level of Korea by about 0.85m-1.29m. Consequently, flood damage in the coastal area would likewise increase and the scale of damage would also become much larger. Various researches have been conducted to efficiently respond to natural disasters caused by climate change. However, there haven’t been many researches related to the analysis and evaluation of coastal area flood vulnerability caused by the rise in sea level. Hence, this study selected Gilsan River basin, a branch of Geum River as the subject matter and tried to evaluate the effect of sea level rise caused by climate change on the coastal area and adjacent rivers. This study also calculated the change in water quantity in the coastal area by considering the sea level rise as well as the future precipitation according to climate change. It also prepared/compared the relevant flood inundation map. The study result showed that the overall flood level increased as the elevation of the water surface rose due to the rise in sea level. In addition, the extent of increase in flood level caused by sea level rise was greater at a location nearer the outlet and it was smaller at a place farther from the outlet. Based on this result, it could be verified that in coastal rivers, climate change can have an effect not only on the precipitation increase but also on the flood water level and flood inundation due to the rise in sea level. The result of this study could be used as basic data for creating technology that would assess the flood vulnerability of coastal urban regions and evaluate preventive measures for coastal disaster risks.

Flood Simulation and Economic Analysis Considering Stormwater Drainage Pumping Stations

Choi, Changhyun,Kim, Yonsoo,Kim, Soojun,Kim, Kyungtae,Kim, Hung Soo 한국방재학회 2015 한국방재학회 학술발표대회논문집 Vol.14 No.-

Global climate change has made natural disasters become large-scale, diversified, and concentrated, causing social and economic damages one after another. The frequency of natural disasters and the scale of subsequent damages are continuously increasing and more than 90% of damages are caused by rainfall, wind speed, and snowfall. In particular, flood damage accounts for the greatest percentage of damage, which prompts us to prepare necessary preventive measures. Flood damage caused by river inundation often occurred in the past. Recently, however, inland flood damages, such as the inundation of Gangnam Station in 2011 and 2012, caused by urbanization have been increasing, which makes it necessary to simulate flood inundation and calculate the damages while considering the effect of inland inundation as well as river inundation. Accordingly, this study analyzed the inland inundation reduction effect through a simulation of flood inundation utilizing flood pumping stations in Anyang River. An economic analysis was also conducted. In addition, this study prepared/compared the flow inundation map based on the existence and operation of flood pumping stations during a localized heavy rainfall event and tried to analyze the economic feasibility by comparing the expected flood damage and the cost of flood pumping stations using Multi-dimensional Flood Damage Assessment. Through this study, results will be provided as reference data for qualitative flood inundation simulation and economic analysis of the basin where natural discharge of direct runoff is impossible and compulsive drainage is taking place.

Peri-operative Inflammatory Marker as a Predictive Factor for Prolonged Post-operative Ileus After Gastrectomy for Gastric Cancer

( Yonsoo Kim ),( Young Min Kim ),( Jie-hyun Kim ),( Young Hoon Youn ),( Jong Won Kim ),( Hyojin Park ) 대한소화기기능성질환·운동학회 2021 Journal of Neurogastroenterology and Motility (JNM Vol.27 No.4

Background/Aims Although prolonged post-operative ileus (PPOI) is an important factor for the prolonged length of post-operative hospital stay, there is still a lack of effective predictive and therapeutic methods for PPOI. Previous studies reported that increased inflammatory markers, such as C-reactive protein (CRP) level and neutrophil to lymphocyte ratio (NLR), are associated with malignancies. The aim of our study is to elucidate the association between peri-operative inflammatory markers and PPOI after gastrectomy for gastric cancer. Methods We enrolled patients who received gastrectomy for gastric cancer from June 2013 to January 2016 at a single tertiary referral center in Seoul, Korea. We evaluated peri-operative inflammatory markers, including CRP level, NLR, and platelet to lymphocyte ratio (PLR) of enrolled patients. We compared these data between control group and PPOI group. Results A total of 390 subjects were enrolled in this study, and 132 patients (33.8%) showed PPOI. In univariate analysis, preoperative CRP level and NLR, post-operative day (POD) 1 CRP level, NLR, and PLR, and POD3 CRP level, NLR, and PLR were significantly associated with PPOI. In multivariate analysis, preoperative NLR (P = 0.014), POD1 NLR (P = 0.019), POD3 CRP (P = 0.004), and POD3 NLR (P = 0.008) were independent risk factors for PPOI. Conclusions Peri-operative inflammatory markers, such as CRP level and NLR, are useful predictive factors for PPOI who received gastrectomy for gastric cancer. Moreover, prophylactic antibiotics and anti-inflammatory drugs can be preventive and therapeutic agents for PPOI. (J Neurogastroenterol Motil 2021;27:588-595)

한강유역의 갈수빈도 해석에 기후변화가 미치는 영향

김연수(Kim Yonsoo),김수전(Kim Soojun),전환돈(Jun Hwandon),김형수(Kim Hungsoo),김병식(Kim Byungsik) 대한토목학회 2009 대한토목학회 학술대회 Vol.2009 No.10

빅 데이터 분석 기법을 이용한 풍수해 복원탄력성 지표 개발 및 평가: (1) 복원탄력성 지표 개발

김연수(Kim Yonsoo),최창현(Choi Changhyun),배영혜(Bae Younghye),김동현(Kim Donghyun),김덕환(Kim Deokhwan),김형수(Kim Hung Soo) 한국방재학회 2018 한국방재학회지 Vol.18 No.4

In this study, we developed indicators for evaluation of storm and flood resilience using big data analysis. Standard terms were selected to collect data necessary for development of indicators and unstructured data such as papers and reports were collected. Preprocessing such as duplicate document processing, specialized dictionary registration, and stop word removal was performed on the collected data. Classification criteria were selected and indicators of the previous studies were reclassified by the classification criteria. Representative keywords were selected by each classified indicators and the related search words for each representative keywords were extracted by analysis of related search words. The extracted search terms were applied to the collected unstructured data, and 83 resilience indicators were developed by selecting detailed indicators and proxy variables in accordance with the selection criteria. The developed storm and flood resilience indicators can be used as a basic data of evaluation of storm and flood resilience for effective disaster management. 본 연구에서는 빅 데이터 분석 기법을 이용하여 풍수해 복원탄력성 평가에 필요한 지표를 개발하였다. 지표 개발에 필요한 데이터를 수집하기 위해 기준용어를 선정하였고, 논문과 보고서 등의 비정형 데이터를 수집하였다. 수집된 데이터에 중복문서 처리, 전문용어 사전 등록, 불용어 처리의 전처리 과정을 진행하였고, 분류기준을 선정하여 선행연구들의 지표를 재분류하였다. 분류된 지표별로 대표 키워드를 선정하고, 연관 검색어 분석을 통해 대표 키워드별 연관 검색어를 추출하였다. 추출된 연관 검색어를 수집된 비정형 데이터에 적용하였고, 선정기준에 부합되는 상세지표와 대리변수를 선정하여 총 83개의 복원탄력성 지표를 개발하였다. 개발된 복원탄력성 지표는 효과적인 재난관리를 실시하기 위한 풍수해 복원탄력성 평가의 기초자료로 사용될 수 있을 것이다.

빅 데이터 분석 기법을 이용한 풍수해 복원탄력성 지표 개발 및 평가: (2) 복원탄력성 평가

최창현(Choi Changhyun),김연수(Kim Yonsoo),김종성(Kim Jongsung),김동현(Kim Donghyun),김정욱(Kim Jungwook),김형수(Kim Hung Soo) 한국방재학회 2018 한국방재학회지 Vol.18 No.4

본 연구에서는 빅 데이터 분석 기법을 이용하여 풍수해 복원탄력성을 평가할 수 있는 방안을 제시하였다. 적정 지표 선정을 위해 빅 데이터 분석 기법이 적용된 풍수해 복원탄력성 지표에 표준화 방법 및 요인분석을 적용하였고, TF-IDF (Term Frequency-Inverse Document Frequency)를 이용하여 각 지표별 가중치를 산정하였다. 본 연구에서 개발된 풍수해 복원탄력성 평가 방안을 이용하여 안양천 유역의 시군구별 풍수해 복원탄력성을 평가하였고, 이를 지역안전도 평가 결과와 비교 및 검토하였다. 개발된 연구 성과는 기존의 재난관리 분야에 적용이 미비하였던 빅 데이터 분석 기법의 활용 방안을 제시하였고, 기후변화로 인해 자연재난의 강도 및 빈도가 증가하고 있는 상황에서 효율적인 재난관리를 실시하기 위한 기초자료로 활용할 수 있을 것으로 기대된다. In this study, we proposed a method to evaluate the resilience of storm and flood using big data analysis. Standardization method and factor analysis were applied to storm and flood resilience indicators with big data analysis technique for indicator selection. And the weights for each indicator were calculated using the TF-IDF (Term Frequency-Inverse Document Frequency). The storm and flood resilience was evaluated municipality of city, town, and county in Anyang river basin using the storm and flood resilience evaluation method developed in this study and compared with the result of the regional safety assessment. The results of this research suggested the application methodology of big data analysis techniques which were not applied to the existing disaster management field. And it is expected that it will be used as basic data for effective disaster management in the situation where the intensity and frequency of natural disasters are increasing due to climate change.

Identifying and Evaluating Chaotic Behavior in Hydro-Meteorological Processes

Kim, Soojun,Kim, Yonsoo,Lee, Jongso,Kim, Hung Soo Hindawi Limited 2015 Advances in meteorology Vol.2015 No.-

<P>The aim of this study is to identify and evaluate chaotic behavior in hydro-meteorological processes. This study poses the two hypotheses to identify chaotic behavior of the processes. First, assume that the input data is the significant factor to provide chaotic characteristics to output data. Second, assume that the system itself is the significant factor to provide chaotic characteristics to output data. For solving this issue, hydro-meteorological time series such as precipitation, air temperature, discharge, and storage volume were collected in the Great Salt Lake and Bear River Basin, USA. The time series in the period of approximately one year were extracted from the original series using the wavelet transform. The generated time series from summation of sine functions were fitted to each series and used for investigating the hypotheses. Then artificial neural networks had been built for modeling the reservoir system and the correlation dimension was analyzed for the evaluation of chaotic behavior between inputs and outputs. From the results, we found that the chaotic characteristic of the storage volume which is output is likely a byproduct of the chaotic behavior of the reservoir system itself rather than that of the input data.</P>

Clinical Impact and Durabilty of Hepatitis B Surface Antigen Seroclearance in Untreated and Nucleos(t)ide Analogue Treated Patients

( Yonsoo Kim ),( Hyun Woong Lee ),( Jung Il Lee ),( Kwan Sik Lee ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: The durability of nucleos(t)ide analogue (NA)-induced hepatitis B surface antigen (HBsAg) seroclearance is uncertain compared with HBsAg seroclearance of non-treated patients. We investigated to reaffirm that the quality of HBsAg seroclearance in NA is as good as that occurring spontaneously. Also, the occurrence of hepatocellular carcinoma (HCC) was investigated. Methods: A cohort study was conducted using data from Gangnam Severance Hospital. We identified all subjects with positive HBsAg between January 1, 2001 and March 21, 2018. NA use, liver biochemistries, serial HBsAg and anti-HBs results were retrieved. The primary endpoint was confirmed HBsAg seroclearance, defined least two negative HBsAg test results, with the last HBsAg test being negative in patients with chronic hepatitis B (CHB). The secondary endpoint was to evaluate the incidence of hepatocellular carcinoma (HCC) after HBsAg seroclearance in untreated and NA-treated patients. Results: A total of 145 CHB patients with HBsAg seroclearance were included for analysis. In patients with spontaneous HBsAg seroclearance (n = 132), 105 patients (79.5%) had confirmed HBsAg seroclearance and 2 patients (1.5%) had HBsAg seroreversion. In patients with NA-induced HBsAg seroclearance (n = 13), 10 patients (76.9%) had confirmed HBsAg seroclearance and HBsAg seroreversion was not observed. 1 patient (7.7%) had received consolidation therapy for < 6 months, 1 patient (7.7%) had received it for 6-12 months and 11 patients (84.6%) had received it for ≥12 months. The incidence rate of HCC in patients with HBsAg seroclearance was 6.21%. At a median (interquartile range) follow-up of 12 years, 5 untreated patients developed HCC. 4 NA-treated patients developed HCC. 6 patients were male aged >50 years (NA-treated patients: 2, untreated patients: 4), and 3 patients were male aged 50 years (NA-treated patients: 2 (age 47, 39), untreated patients: 1 (age 37)). There was no female patient who developed HCC with HBsAg seroclearance. Similar findings were observed in patients with spontaneous and antiviral treatment-induced HBsAg seroclearance. Conclusions: NA-induced HBsAg seroclearance is as durable as spontaneous HBsAg seroclearance. All male patients are still at risk of HCC even if the incidence of HCC is very low.

다중최적화기법을 이용한 분포형 수문모형의 최적 분포형 선택

김연수(Yonsoo Kim),김태균(Taegyun Kim) 한국습지학회 2020 한국습지학회지 Vol.22 No.1

본 연구에서는 다중최적화기법을 이용하여 분포형 수문모형의 매개변수 보정 과정에서 분포형의 정도가 융설과 유량의 최적화에 어떠한 영향을 미치고 있는 가를 연구하였다. 분포형 수문모형으로는 HL-RDHM를 이용하였고, 분포형 정도에 따라 집중형, 준분포형, 완전분포형 등 3개의 모형을 구성하여 최적 매개변수를 산정하였다. 유역은 108개의 격자로 구성되며, 격자별로 융설과 관련하여 15개, 유출량 관련 13개의 매개변수를 다중최적화기법인 MOSCEM를 이용하여 최적화하였다. 최적 매개변수 산정을 위하여 2004-2005년의 기상학적 자료와 융설량과 유출량 관측자료가 이용되었고, 최적화된 매개변수를 2001-2004년의 자료를 이용하여 검증하였다. 다중최적화기법 적용 결과 집중형의 경우, 초기 값에 의한 결과로부터 RMSE 값이 융설량은 평균 35%, 유출량은 약 42% 개선되었고, 준분포형과 완전분포형의 경우는 융설량은 평균40%, 유출량은 약 43% 정도의 RSME 값이 향상되었다. 전반적으로 집중형보다는 분포형 모형이 최적화 과정에서 융설과유출량 예측에 더 나은 성과를 보여주었지만, 준포형과 완전분포형의 경우 최적화 성과에서 큰 차이를 보이지 않았고, 유출보다는 융설에서 분포형 정도에 따른 모형의 민감도가 더 높은 것을 확인되었다. The purpose of this study is to investigate how the degree of distribution influences the calibration of snow and runoff in distributed hydrological models using a multi-criteria calibration method. The Hydrology Laboratory-Research Distributed Hydrologic Model (HL-RDHM) developed by NOAA-National Weather Service (NWS) is employed to estimate optimized parameter sets. We have 3 scenarios depended on the model complexity for estimating best parameter sets: Lumped, Semi-Distributed, and Fully-Distributed. For the case study, the Durango River Basin, Colorado is selected as a study basin to consider both snow and water balance components. This study basin is in the mountainous western U.S. area and consists of 108 Hydrologic Rainfall Analysis Project (HRAP) grid cells. 5 and 13 parameters of snow and water balance models are calibrated with the Multi-Objective Shuffled Complex Evolution Metropolis (MOSCEM) algorithm. Model calibration and validation are conducted on 4km HRAP grids with 5 years (2001-2005) meteorological data and observations. Through case study, we show that snow and streamflow simulations are improved with multiple criteria calibrations without considering model complexity. In particular, we confirm that semi- and fully distributed models are better performances than those of lumped model. In case of lumped model, the Root Mean Square Error (RMSE) values improve by 35% on snow average and 42% on runoff from a priori parameter set through multi-criteria calibrations. On the other hand, the RMSE values are improved by 40% and 43% for snow and runoff on semi- and fully-distributed models.

태풍피해자료를 이용한 태풍위험지수 개발

김연수(Kim, Yonsoo),이보림(Lee, Borim),김태균(Kim, Taegyun) 한국방재학회 2019 한국방재학회논문집 Vol.19 No.7

태풍피해는 호우로 인한 홍수, 강풍, 풍랑 등 3가지 피해가 동시에 발생하는 재해로, 지난 10년간 피해액 기준으로 가장 큰 피해를 일으켰다. 본 연구에서는 전국 229개 시군구를 대상으로 1994년 이후 발생한 태풍피해자료를 이용하여 태풍위험지수(TRI)를 개발하였다. 태풍위험지수는 PSR 구조체계를 이용하여 시군구별로 개발하였다. 압력지수(PI)는 수문기상, 지역특성, 사회경제적 지표 등 10개 지표를, 상태지수(SI)는 피해 관련 3개 지표를, 대책지수(RI)는 재정상태, 방재관련 사업, 시설 등 6개 지표를 이용하였다. 지수산정을 위한 각 지표의 가중치는 엔트로피 방법을 이용하였다. 압력지수는 수도권과 남해안 지역이 높게 나타났고, 상태지수는 남해안과 동해안 지역이 높게 나타났으나, 대책지수는 지역적 경향성을 찾기 어려웠다. 태풍위험지수는 남해안과 동해안 및 지리산, 덕유산 인근 지역이 높게 나타났으며, 이는 태풍피해 다발지역과 일치하는 것을 알 수 있다. 개발된 태풍위험지수는 태풍에 위한 피해를 감소하기 위한 대비와 방재 관련 사업의 우선순위를 결정하는데 이용될 수 있을 것이다. Typhoon cause damage through simultaneous flooding, strong winds, and storms; they have been one of the most damaging disasters of the last decade. In this study, we develop a typhoon risk index (TRI) based on records of typhoon damage that occurred in 229 municipalities across South Korea since 1994. The TRI employs a pressure-state-response (PSR) framework system. For the pressure index (PI), we use ten indicators that represent hydro-meteorological, regional, and socio-economic characteristics. The state index (SI) includes three indicators related to typhoons and the response index (RI) comprises six indicators including financial status and disaster mitigation-related projects and facilities. The weighting of each indicator for the TRI was calculated using an entropy method. The PIs are higher in the Seoul metropolitan and southern coast areas of the Korean peninsula. The SIs are higher for the southern and eastern coastal areas. It is not easy to determine a regional trend for the RIs. The TRI is higher for the southern and eastern coasts and the Jirisan and Deogyusan areas. These regions are consistent with the areas where typhoons have frequently caused damage. The TRI developed in this research will contribute to decision-making about the priority of disaster prevention projects to mitigate typhoon damage.