수도권 집중호우에 따른 산사태 발생 위험지역 분석

차성은(Cha, Sung Eun),임철희(Lim, Chul Hee),김지원(Kim, Ji Won),김문일(Kim, Moon Il),송철호(Song, Chol Ho),이우균(Lee, Woo Kyun) 대한공간정보학회 2018 대한공간정보학회지 Vol.26 No.3

본 연구는 산사태 위험지도의 정확도를 향상시킬 수 있는 방안을 모색하기 위해, 2011년 7월 26일부터 28일까지 서울지역에서 집중호우 시 발생한 산사태를 바탕으로 지형공간 및 기상인자를 이용해 산사태 위험지도를 작성하였다. 그 결과, 서울지역의 지형공간 및 기상인자를 모두 고려한 통합된 산사태 위험지도에서는 총 19회의 산사태중 18회(약 95%)가 높은 산사태 위험 지역(high landslide risk area; HLRA)에서, 나머지 1회(약 5%)는 중간 산사태 위험 지역(medium landslide risk area; MLRA)에서 발생하였다. 이를 통해 본 연구에서 지형공간인자를 기반으로 도출한 산사태 위험지역은 실제 집중호우 발생 시 산사태 발생 위험이 상당히 높아짐을 확인하였다. This study aims to find the method to enhance the accuracy of landslide risk map. The landslide risk map was produced based on the landslides occurred during heavy rainfall events from July 26 to 28 in 2011. For the landslide risk map, geospatial and climate factors were used. As a result, in the integrated landslide risk map of Seoul, which considered geospatial factors and climate factors, 18 out of 19 landslides (about 95%) occurred in the high landslide risk area (HLRA) and remaining one (about 5%) was in the medium landslide risk area (MLRA). These results show that the risk of landslides is significantly increased if the climate is exposed to the landslide hazard area analyzed by geospatial factors.

국내 COVID-19의 공간분포특성 분석

차성은(Cha, Sung Eun),조정선(Jo, Jeong Seon),조정은(Jo, Jeong Eun),이우균(Lee, Woo Kyun),김대철(Kim, Dae Cheol) 대한공간정보학회 2021 대한공간정보학회지 Vol.29 No.2

위성영상과 음영기복도를 이용한 오대산 지역 진앙의 위치와 선구조선의 관계 분석

차성은 ( Sung-eun Cha ),지광훈 ( Kwang-hoon Chi ),조현우 ( Hyun-woo Jo ),김은지 ( Eun-ji Kim ),이우균 ( Woo-kyun Lee ) 한국지리정보학회 2016 한국지리정보학회지 Vol.19 No.4

본 연구에서는 LANDSAT 8호, KOMPSAT 2호 위성영상과 1/25,000 수치지형도를 기반으로 작성된 음영기복도를 이용하여 2007년 1월 20일 오대산 지역에서 발생한 약 4.8의 중규모 지진과 선구조선의 관계를 분석하였다. 대부분의 선행연구는 지체구조와 관련된 선구조선 분석 연구를 하였으며, 주로 2차원의 위성영상과 음영기복도를 활용하였기에 지형의 기복 등에 대한 판독이 어려워 선구조선 추출이 제한적이었다. 본 연구에서는 이를 보완하기 위해 수치표고모델(Digital Elevation Model; DEM)을 기반으로 작성한 3차원 입체 영상과 수계망 분석을 통해 지형의 기복, 수계의 연결성 등을 판독해 선구조선을 추출하여, 2차원 영상에서 나타나는 시각적인 판독에 의한 오류를 최소화한 선구조선 판독도를 작성하였다. 또한 진앙에 대한 선구조선의 통계 요소별 밀도를 추정하기 위해 spline 내삽법을 이용하여 선구조선의 빈도, 교차점, 길이에 대한 밀도를 계산하였다. 그리고 진앙에서의 선구조선 밀도가 얼마나 밀집되어 있는지 정량적으로 표현하기 위하여 각 격자 내의 선구조선 밀도에 대해 최대 선구조선 밀도로 나누는 상대밀도 값(Value of the Relative Density; VRD)을 계산하는 알고리즘을 개발하여 밀도도(density map)를 작성하였다. 각 영상의 진앙에서의 VRD는 최소 약 0.60에서 최대 약 0.90으로 나타났지만, 각 영상별 광원의 고도각과 방위각이 차이가 있어 영상별 VRD보다 통계 요소별 VRD의 평균치를 사용하였다. 그 결과, 빈도의 평균 VRD는 약 0.85로 교차점과 길이의 평균 VRD보다 약 21% 높게 나타나, 선구조선의 빈도 요소가 진앙의 위치와의 관계가 가장 밀접함을 확인하였다. 이와 같이 3차원 영상의 선구조선 추출을 통한 밀도 분석 기술은 향후 지진 발생 가능 지역 분석에 기초자료로써의 의미가 있을 것으로 기대된다. The purpose of this paper is to analyze the relationship between the location of the epicenter of a medium-sized earthquake(magnitude 4.8) that occurred on January 20, 2007 in the Odaesan area with lineament features using a shaded relief map(1/25,000 scale) and satellite images from LANDSAT-8 and KOMPSAT-2. Previous studies have analyzed lineament features in tectonic settings primarily by examining two-dimensional satellite images and shaded relief maps. These methods, however, limit the application of the visual interpretation of relief features long considered as the major component of lineament extraction. To overcome some existing limitations of two-dimensional images, this study examined three-dimensional images, produced from a Digital Elevation Model and drainage network map, for lineament extraction. This approach reduces mapping errors introduced by visual interpretation. In addition, spline interpolation was conducted to produce density maps of lineament frequency, intersection, and length required to estimate the density of lineament at the epicenter of the earthquake. An algorithm was developed to compute the Value of the Relative Density(VRD) representing the relative density of lineament from the map. The VRD is the lineament density of each map grid divided by the maximum density value from the map. As such, it is a quantified value that indicates the concentration level of the lineament density across the area impacted by the earthquake. Using this algorithm, the VRD calculated at the earthquake epicenter using the lineament``s frequency, intersection, and length density maps ranged from approximately 0.60(min) to 0.90(max). However, because there were differences in mapped images such as those for solar altitude and azimuth, the mean of VRD was used rather than those categorized by the images. The results show that the average frequency of VRD was approximately 0.85, which was 21% higher than the intersection and length of VRD, demonstrating the close relationship that exists between lineament and the epicenter. Therefore, it is concluded that the density map analysis described in this study, based on lineament extraction, is valid and can be used as a primary data analysis tool for earthquake research in the future.

공장 혈관이형성증

김경영(Gyeong Young Kim),김나영(Na Young Kim),전호춘(Ho Choon Jeon),차성은(Sung Eun Cha),김지영(Ji Young Kim),이계희(Kye Heui Lee),양대현(Dae Hyun Yang),박경주(Gyung Joo Park),최신은(Shin Eun Choi) 대한소화기학회 1995 대한소화기학회지 Vol.27 No.5

Angiodysplasia, an important vascular lesion of the gut, defined by the presence of ectasia of normal preexisting intestinal submucosal veins and overlying mucosal capillaries, is a source of major morbidity from bleeding. With the development of diagnostic angiography, angiodysplasia of the bowel has been recognized as a frequent cause of significant intestinal bleeding, particularly in elderly patients. Its cause is unknown but considered mostly to be acquired as a result of a degenerative process associated with aging. We experienced one case of jejunal angiodysplasia in a 64-year old man, diagnosed by angiography, and selective jejunal resection was conducted with the aid of intraoperative mesenteric arterial methylene blue injection, administered via a catheter superselectively positioned in the appropriate jejunal arterial branch prior to operation. This patient has been followed up for 6 months without rebleeding. (Korean J Gastroenterol 1995;27:588- 594)

위점막내 Helicobacter pylori 검사방법의 상호비교에 관한 연구

김나영(Na Young Kim),김경영(Kyeong Young Kim),김지영(Ji Young Kim),전호춘(Ho Cheun Jeon),차성은(Sung Eun Cha),이계희(Kye Heui Lee),구명숙(Myoung Sook Koo),최신은(Shin Eun Choi) 대한내과학회 1994 대한내과학회지 Vol.47 No.2

N/A Objectives: Many studies about the role of H. pylori on the gastritis, duodenal ulcer, benign gastric ulcer and stomach cancer have been carried out actively and many test methods of detecting H. Pylori have been developed. However, few studies have been reported about the sensitivity or applicability of these test methods and it can be seen that little consideration was taken into the sensitivity of these methods in some papers. This study was done to evaluate the sensitivity of each test method for identifying H. pylori infection and to evaluate time distribution of positive response in the CLO test. Methods: Four different test methods for identifying H. Pylori infection - Gram stain of touch print, CLO test, culture, H&E stain were taken in the 280 patients with duodenal ulcer. The sensitivity of each test was evaluated for the 264 H. pylari positive cases and positive time in the CLO test was measured. Results: 1) All four tests were positive in 80 cases (30.3%), three tests or more were positive in 197 cases (74.7%), and two tests or more were positive in 241 cases (91.3%). 2) There were 23 cases (8.7%) indicating H. pylori positive according to only one test, of which 15 cases (5.7%) were positive according to Gram stain and 8 cases (3.0%) according to CLO test, Either Gram stain or CLO test was positive in 100% of 264 H. pylori positive cases. 3) The sensitivity of Gram stain of touch print was 94.7%, that of CLO test 90.5% and that of H&E stain 69.3%, which was significantly lower than that of Gram stain or CLO test. The sensitivity of culture was 40.2% and it was significantly lower than that of H4E stain. 4) The positivie rate of Gram stain in the 106 culture positive cases was 100% (106 cases) and that of CLO test and H8rE stain were 93.4% (99 cases) and 77.4% (82 cases), respectively. 5) Of the 239 positive CLO tests, 129 cases (54.0%) indicated H. pylori positive within 20 min, 204 cases (85.4%), 231 cases (96.7%) and 239 cases (100%) within 1 hr, 3 hrs and 24 hrs, respectively. 6) Of the 99 culture and CLO test positive cases, 62 cases (62.6%) indicated H. pylori positive within 20 min in CLO test, and 87 cases (87.9%), 93 cases (93.95%) and 99 cases (100%) within 1 hr, 3 hrs and 24 hrs, respectively. Conclusion: From these results, we can conclude that the most sensitive test in detecting H. pylori is the Gram stain of touch print, and the next is CLO test. Just these two tests enable us to determine H. Pylori infection for almost all patients, this signifies that these two tests, not all of the four tests, are sufficient for H. pylori infection test. In the CLO test, 96.7% of the positive cases were diagnosed to be positive within 3 hrs, so that CLO test is considered to be a very speedy test in the diagnosis of H. pylori infection.