GIS 공간분석 기반의 토석류피해지 토사유출 특성 연구

서준표(Seo, Junpyo),우충식(Woo, Choongshik),이창우(Lee, Changwoo),김동엽(Kim, Dongyeob) 한국방재학회 2018 한국방재학회논문집 Vol.18 No.5

산사태·토석류가 발생했을 때, 하류로 유출되는 토사량을 예측하는 것은 사방댐 규모·배치 등 사방사업에서 중요하다. 본 연구에서는 산사태·토석류 피해지역에 항공영상 촬영을 실시하고, GIS 공간분석을 수행하였다. 토석류 발생시 하류로 유출되는 토사량에는 계류길이, 계류폭, 발생원의 붕괴량이 영향을 미치는 것으로 나타났다. 하류로 유출되는 누적 토사량은 계류길이와 높은 상관관계로 나타났고, 이를 이용하여 토사유출량을 추정할 수 있는 식을 개발하였다. 개발된 식은 그룹화를 실시하고, 최종적으로 4가지 추정식을 제안하였다. 제안된 토석류 토사유출량 추정식은 토석류 발생시 하류로 유출되는 토사량을 예측하고, 사방댐 설계시 규모·배치 의사결정에 활용함으로써 재해예방 등 산지 하류지역의 방재효과에 기여할 수 있다. When landslides and debris flows occur, predicting sediment discharge is important for soil erosion control. In this study, aerial photography and GIS spatial analysis were carried out on a landslide and debris flow area. The sediment discharge was most affected by the flow length, flow width, and the amount of slope failure within the source area. In particular, the sediment discharge was highly correlated with the flow length. We have developed an equation that can estimate sediment discharge. The developed equations are grouped and four estimation equations are proposed. The developed sediment discharge equation can predict the amount of soil runoff downstream when a landslide and debris flow occur in a forest watershed. In addition, it can be used to make design decisions concerning the scale and location of erosion control dams, contributing to disaster prevention in downstream areas.

The Effects of Peri-Urethral Thrombin Instillation on Post-Operative Hematuria and Voiding Function in Patients with Benign Prostatic Hyperplasia (BPH) Undergoing Trans-Urethral Prostate Surgery

Joung Won Sung(Joung Won Sung),Gee Hyun Song(Gee Hyun Song),Woong Na(Woong Na),Junpyo Hong(Junpyo Hong),So Mi Park(So Mi Park),Seong Pyo Seo(Seong Pyo Seo),Jong Hyun Yoon(Jong Hyun Yoon) 대한임상노인의학회 2023 대한임상노인의학회지 Vol.24 No.2

Background: To evaluate the efficacy of peri-urethral thrombin instillation at the surgical site after trans-urethral prostate surgery in benign prostatic hyperplasia (BPH), with the objective of reducing post-operative hematuria and preserving voiding function. Methods: The study was retrospectively analyzed a total of 122 patients who had trans-urethral prostate surgery between January 2019 and March 2023. Among these, 33 received thrombin instillation, while 89 did not receive it. In the test group, a mixture of 5 cc of saline solution and 5,000 IU of thrombin was instilled below the balloon, targeting the surgical site by inserting a 5 Fr feeding tube along with the Foley catheter. We compared hematologic data and uroflowmetry (UFM) between pre and post-operative periods, the duration of continuous bladder irrigation (CBI) and Foley catheter indwelling period. Results: The mean age and prostate size in the test group were 71.52±7.15 years and 54.05±24.73 g, while 71.38±8.22 years and 64.52±28.43 g in the control group. The prostate resected weight was 24.97±15.77 g and 27.58±17.00 g respectively. The hemoglobin and platelet levels were −1.05±0.81 g/dL and −42.79±35.59×103/L in the test group, and −1.08±0.97 g/dL and −27.93±40.49×103/L, in the control group. The test group showed better outcomes in CBI application time (21.31±12.15 hours) and Foley catheter indwelling time (50.97±14.63 hours) compared to the control group (34.42±22.68 hours and 70.33±33.95 hours) (P<0.001). Conclusion: After trans-urethral prostate surgery, thrombin agent instillation can prevent post-operative hematuria and facilitate quicker recovery to daily activities.

A Design of Dual Frequency Bands Time Synchronization System for Synchronized-Pseudolite Navigation System

Seo, Seungwoo,Park, Junpyo,Suk, Jin-Young,Song, Kiwon The Institute of Positioning 2014 Journal of Positioning, Navigation, and Timing Vol.3 No.2

Time synchronization system using dual frequency bands is designed and the error sources are analyzed for alternative synchronized-pseudolite navigation system (S-PNS) which aims at military application. To resolve near/far problem, dual frequency band operation is proposed instead of pulsing transmission which degrades level of reception. In dual frequency operation H/W delay should be considered to eliminate errors caused by inter-frequency bias (IFB) difference between the receivers of the pseudolites and users. When time synchronization is performed across the sea, multipath error is occurred severely since the elevation angle between pseudolites is low so total reflection can be happened. To investigate the difference of multipath effects according to location, pseudolites are set up coastal area and land area and performances are compared. The error source related with tropospheric delay is becoming dominant source as the coverage of the PNS is broadening. The tropospheric delay is measured by master pseudolite receiver directly using own pseudorange and slave pseudorange. Flight test is performed near coastal area using S-PNS equipped with developed time synchronization system and test results are also presented.

A Genomic Approach to Identify the Different between Acute and Chronic UVB Exposures in the Causation of Inflammation and Cancer

JunPyo Han,Yujin Jang,Dong Yeop Shin,Jun Lee,Young Rok Seo 대한암예방학회 2022 Journal of cancer prevention Vol.27 No.4

As a principal component of solar radiation, ultraviolet B (UVB) exposure can be harmful depending on the duration and intensity because the human body can easily be exposed to it. Many studies have demonstrated that UVB causes a series of inflammatory and other skin disorders. UVB has been classified as the Group 1 carcinogen by the International Agency for Research on Cancer. Diverse studies have focused on UVB exposure but the complex perspective of acute and chronic UVB exposure is still lacking. This review presents the differences between acute and chronic exposure to UVB and summarizes public information in terms of toxicogenomic characteristics. We also demonstrated the differences between adverse effects of acute and chronic UVB exposure on the skin system. From the published literatures, we compared the biological pathways predict of the adverse effects caused by each UVB exposure type. Furthermore, our review not only clarifies the differences in each UVB exposure network but also suggests major hub genes related to cellular mechanisms and diseases that are thought to be affected by acute and chronic UVB exposure.

Application of GeoWEPP to determine the annual average sediment yield of erosion control dams in Korea

Hakjun Rhee,Junpyo Seo 충남대학교 농업과학연구소 2020 Korean Journal of Agricultural Science Vol.47 No.4

붕괴모의실험을 통한 산사태 조기경보용 계측센서의 반응성 분석 및 활용성 고찰

강민정,서준표,김동엽,이창우,우충식,Kang, Minjeng,Seo, Junpyo,Kim, Dongyeob,Lee, Changwoo,Woo, Choongshik 한국산림과학회 2019 한국산림과학회지 Vol.108 No.2

The goal of this study was to analyze the reactivity of a volumetric water content sensor (soil moisture sensor) and tensiometer and to review their use in the early detection of a shallow landslide. We attempted to demonstrate shallow and rapid slope collapses using three different soil ratios under artificial rainfall at 120 mm/h. Our results showed that the measured value of the volumetric water-content sensor converged to 30~37%, and that of the tensiometer reached -3~-5 kPa immediately before the collapse of the soil under all three conditions. Based on these results, we discussed a temporal range for early warnings of landslides using measurements of the volumetric water content sensors installed at the bottom of the soil slope, but could not generalize and clarify the exact timing for these early warnings. Further experiments under various conditions are needed to determine how to use both sensors for the early detection of shallow landslides. 이 연구는 붕괴모의실험을 통하여 체적함수비센서와 텐시오미터의 반응성을 분석하고, 산사태 조기경보용으로의 활용성을 검토하기 위해 수행되었다. 산림토양과 사질토의 배합비율을 조정한 3개의 토양조건에서 120 mm/h의 인공강우를 적용하여 얕은 깊이에서 빠르게 진행되는 붕괴형태를 실험적으로 모의하고, 그 과정에서의 두 센서의 반응을 분석하였다. 그 결과, 모든 실험조건에서 체적함수비센서 및 텐시오미터의 계측값은 각각 30~37%, -3~-5 kPa으로 수렴된 이후에 붕괴가 발생하였다. 실험결과를 토대로 토층 최하부에 설치된 체적함수비센서의 계측값을 활용하여 조기경보 발생시점의 범위를 논의하였으나, 이를 일반화하여 명확한 시점으로 규정할 수는 없었다. 두 센서를 실용적인 차원에서 산사태 조기경보용으로 활용하기 위해서는 다양한 조건에서의 추가적인 실험 및 검증이 필요할 것으로 생각되었다.

역사기록서 고찰을 통한 조선시대 산사태 특성 분석

이창우,서준표,강영호,Lee. Changwoo,Seo. Junpyo,Kang. Youngho 한국방재학회 2013 한국방재학회논문집 Vol.13 No.6

본 연구는 조선시대 산사태 발생현황과 특성에 대해서 현시대와 비교 분석하였다. 본 연구에 활용된 역사기록서는 조선왕조실록, 승정원일기, 비변사등록으로 이들 역사기록서에서 산사태, 토석류, 낙석을 포함하는 기록들을 고찰하였다. 조선시대 산사태 발생 원인은 강우가 81%로 가장 높았고, 50년 단위연도별 발생비율은 호우빈도와 유사한 결과로 나타났다. 그리고 월별산사태 발생 피해비율은 8월(30.7%), 7월(22.9%) 9월(18.8%) 순으로 나타났다. 또한 지역별 산사태 발생 피해비율은 강원도(16.3%), 서울(14.4%), 경기도 (13.4%), 경상북도(11.4%), 경상남도(10.9%) 순으로 나타났다. 결론적으로 조선시대의 산사태 특징은 발생원인과 빈발하는 월이 현재와 유사하였다. 또한 지역에 따른 피해발생비율도 유사점은 있었으나, 도심지에서는 다소 차이가 나타났다. 이러한 결과는 미래의 산사태 연구방향 및 정책수립에 대한 기초자료로 활용될 것으로 판단된다. In this study, the characteristic and occurrence on landslide of Joseon Dynasty were analyzed in order to compare with those of the present. Using the historical records on the Annals of Joseon Dynasty(朝鮮王朝實錄). The daily records of royal secretariat of Joseon Dynasty(承政院日記) and Bibyeonsadeungnok(備邊司謄錄), the record of landslide, debris flow and rockfall of Joseon Dynasty was investigated. The major cause of landslide of Joseon Dynasty was rainfall that was occupied by 81%, the ratio of landslide occurrence per 50 years was similar to frequency of torrential rain for same period. The ratio of landslide damage by month was the highest in August(30.7%) and the next was the July(22.9%) and September(18.8%) in order. And the ratio of landslide damage by region was the highest in Kangwon province(16.3%) and the next was the Seoul city(14.4%), Gyeonggi(13.4%), Gyeongbuk(11.4%), Gyeongnam(10.9%) province in order. The result show that causes, occurrence period and the damage ratio by regional on landslide of Joseon Dynasty were similar to those of the present, but there was a little difference in the city area. These results will be helpful to predict landslide trend in the future and set up policy countermeasures for landslide.

Analyzing the Effect of Check Dam in Debris Flow Hazard Map Using Random Walk Model

Song Eu,Chang-Woo Lee,Junpyo Seo,Choongshik Woo 위기관리 이론과 실천 2021 Crisisonomy Vol.17 No.9

토석류는 우리나라 주요 산지토사재해 중 하나로, 토석류로 운송된 다량의 토사가 하류 지역에 퇴적 되어 인명 및 재산피해를 일으키기 때문에 토석류로 인한 피해 범위를 예측하여 경계 피난을 위한 기초자료로 활용하는 것이 중요하다. 우리나라 산림청은 Random Walk Model(RWM)을 활용하여 토석류 피해예측지도를 구축하였다. 한편, 산지계류에 설치되는 사방댐은 토석류 유출을 차단하여 피해면적을 감소시키므로 효과적인 토석류 피해예측지도 활용을 위해서는 사방댐의 효과가 고려되 어야 한다. 이 연구에서는 강원도 소재 9개 사방댐 설치 유역에 대해, 사방댐의 효과를 고려한 RWM 토석류 유출 및 퇴적 모의를 통해 토석류 피해예측지도에 대한 사방댐 효과 적용 가능성을 검토하였 다. 분석결과 RWM을 통해 사방댐의 효과는 일정 부분 재현 가능하였으나, 입력 매개변수 및 모델 구성의 한계로 피해예측범위의 수정은 제한될 것으로 판단되었다. 향후 공간해상도의 개선 및 합리 적 붕괴토사량의 산정을 통해 사방댐의 효과를 반영한 효과적인 토석류 피해예측지도 구축이 가능 할 것으로 판단된다. Debris flow transports lots of sediments downstream that cause damage to human lives and properties. The accurate estimation of the debris flow hazard zone is a critical factor of the successful early-warning and evacuation for reducing the debris flow risk. Korea Forest Service has developed a debris flow hazard map using Random Walk Model (RWM). Meanwhile, because check dams in forest watersheds capture discharged debris, the effect of check dams should be considered for mapping the debris flow hazard zone. This study analyzed the effect of check dams on debris flow discharge using RWM with the check dam module. As a result, RWM seems to simulate the sediment capture by check dams. However, the total deposit areas were not significantly different despite the effect of check dams because of input parameters and the flow direction calculation algorithm of RWM. Further studies on appropriate spatial resolution and initial sediment volume should be conducted to improve the debris flow hazard map.

Accuracy Comparison of GPT and SBAS Troposphere Models for GNSS Data Processing

Park, Kwan-Dong,Lee, Hae-Chang,Kim, Mi-So,Kim, Yeong-Guk,Seo, Seung Woo,Park, Junpyo The Institute of Positioning 2018 Journal of Positioning, Navigation, and Timing Vol.7 No.3

The Global Navigation Satellite System (GNSS) signal gets delayed as it goes through the troposphere before reaching the GNSS antenna. Various tropospheric models are being used to correct the tropospheric delay. In this study, we compared effectiveness of two popular troposphere correction models: Global Pressure and Temperature (GPT) and Satellite-Based Augmentation System (SBAS). One-year data from a particular site was chosen as the test case. Tropospheric delays were computed using the GPT and SBAS models and compared with the International GNSS Service tropospheric product. The bias of SBAS model computations was 3.4 cm, which is four times lower than that of the GPT model. The cause of higher biases observed in the GPT model is the fact that one cannot get wet delays from the model. If SBAS-based wet delays are added to the hydrostatic delays computed using the GPT model, then the accuracy is similar to that of the full SBAS model. From this study, one can conclude that it is better to use the SBAS model than to use the GPT model in the standard code-pseudorange data processing.

Analysis on the Multi-Constellation SBAS Performance of SDCM in Korea

Lim, Cheol-Soon,Park, Byungwoon,So, Hyoungmin,Jang, Jaegyu,Seo, Seungwoo,Park, Junpyo,Bu, Sung-Chun,Lee, Chul-Soo The Institute of Positioning 2016 Journal of Positioning, Navigation, and Timing Vol.5 No.4

A Satellite Based Augmentation System (SBAS) provides differential correction and integrity information through geostationary satellite to users in order to reduce Global Navigation Satellite System (GNSS)-related errors such as ionospheric delay and tropospheric delay, and satellite orbit and clock errors and calculate a protection level of the calculated location. A SBAS is a system, which has been set as an international standard by the International Civilian Aviation Organization (ICAO) to be utilized for safe operation of aircrafts. Currently, the Wide Area Augmentation System (WAAS) in the USA, the European Geostationary Navigation Overlay Service (EGNOS) in Europe, MTSAT Satellite Augmentation System (MSAS) in Japan, and GPS-Aided Geo Augmented Navigation (GAGAN) are operated. The System for Differential Correction and Monitoring (SDCM) in Russia is now under construction and testing. All SBASs that are currently under operation including the WAAS in the USA provide correction and integrity information about the Global Positioning System (GPS) whereas the SDCM in Russia that started SBAS-related test services in Russia in recent years provides correction and integrity information about not only the GPS but also the GLONASS. Currently, LUCH-5A(PRN 140), LUCH-5B(PRN 125), and LUCH-5V(PRN 141) are assigned and used as geostationary satellites for the SDCM. Among them, PRN 140 satellite is now broadcasting SBAS test messages for SDCM test services. In particular, since messages broadcast by PRN 140 satellite are received in Korea as well, performance analysis on GPS/GLONASS Multi-Constellation SBAS using the SDCM can be possible. The present paper generated correction and integrity information about GPS and GLONASS using SDCM messages broadcast by the PRN 140 satellite, and performed analysis on GPS/GLONASS Multi-Constellation SBAS performance and APV-I availability by applying GPS and GLONASS observation data received from multiple reference stations, which were operated in the National Geographic Information Institute (NGII) for performance analysis on GPS/GLONASS Multi-Constellation SBAS according to user locations inside South Korea utilizing the above-calculated information.