• The Journal of Engineering Geology
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• v.33 no.1
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• pp.201-211
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• 2023

This study investigated the damage range of the debris flow to predict the amount of collapsed soil in a landslide event. The height of the collapsed slope and the distance traveled by the collapsed soil were used to predict the total trajectory distance using a random walk model. Debris flow trajectory probabilities were calculated through 10,000 Monte Carlo simulations and were used to calculate the damage range as measured from the landslide scar to its toe. Compiled information on debris flows that occurred in the Cheonwangbong area of Mt. Jirisan was used to test the accuracy of the proposed random walk model in estimating the damage range of debris flow. Results of the comparison reveal that the proposed model shows reasonable accuracy in estimating the damage range of debris flow and that using 10 m × 10 m cells allows the damage range to be reproduced with satisfactory precision.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.188-188
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• 2023

지구온난화, ENSO 등 전지구적인 기후변화 현상으로 위험기상 발생이 증가하고 있다. 한반도는 삼면이 바다에 접하였기 때문에 매우 불안정한 대기로 저기압이 빈번히 통과하는 특징을 가지며, 우리나라는 매년 이상기후로 인한 기상재해로 인명 및 재산 피해가 증가하는 추세를 보이고 있다. 최근 10년간 가장 많이 발생한 피해액 기준 대형 자연재난은 호우로 총 49회 발생하였다. 호우는 다른 기상재해에 비해 발생 시간이 짧고, 공간 규모가 작을 뿐만 아니라 시공간적으로 변동성이 매우 크기 때문에 발생 시 많은 인명 및 재산 피해를 유발한다. 기상청은 호우 외 9가지 기상현상으로 인해 중대 재해 발생이 예상되는 경우 주의를 환기하거나 경고를 예보하는 특보를 발표한다. 현재 사용 중인 호우특보 기준은 기후변화와 위험기상 발생 패턴 변화에 따른 호우 피해와 강우량의 상관성을 고려해 3시간 강우량 개념으로 강우강도, 12시간 강우량 개념으로 누적강우량을 파악할 수 있게 개선한 결과이다. 그러나 지역 특성을 반영하지 아니하고, 하나의 특보 기준 값을 전 지자체에 적용하기 때문에 국지성 집중호우의 지역별 특성을 세세히 반영하지 못하는 등 한계를 보인다. 이와 반대로 영국의 경우 기상특보 기준에 기상현상이 미치는 영향을 포함하였으며, 일본의 경우 우리나라 시군구 개념인 시정촌별로 기상특보 기준을 다르게 설정하여 운영 중이다. 지역 특성을 반영한 해외 기상특보 사례와 달리 우리나라 기상특보는 지역별 위험 및 사회·경제적 취약성을 고려하지 않아 특보 기준 값이 획일화되어 있음을 확인했다. 이에 본 연구는 기상특보 중 호우특보로 연구 범위를 한정하고, 위험기상의 획일적 의사결정 시스템을 보완하기 위해 영향한계강우량과 재해위험성을 고려한 호우특보 기준을 연구하여 제안하고자 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.183-183
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• 2023

Smart water cities (SWC) are urban municipalities that utilizes modern innovations in managing and preserving the urban water cycle in the city; with the purpose of securing sustainability and improving the quality of life of the urban population. Understanding the different urban water characteristics and management strategies of cities situate a baseline in the development of evaluation scheme in determining whether the city is smart and sustainable. This research herein aims to develop measurements and evaluation for SWC Key Performance Indicators (KPIs), and set up a unified global standard and certification scheme. The assessment for SWC is performed in technical, as well as governance and prospective aspects. KPI measurements under Technical Pillar assess the cities' use of technologies in providing sufficient water supply, monitoring water quality, strengthening disaster resilience, minimizing hazard vulnerability, and maintaining and protecting the urban water ecosystem. Governance and Prospective Pillar on the other hand, evaluates the social, economic and administrative systems set in place to manage the water resources, delivering water services to different levels of society. The performance assessment is composed of a variety of procedures performed in a quantitative and qualitative manner, such as computations through established equations, interviews with authorities in charge, field survey inspections, etc. The developed SWC KPI measurements are used to evaluate the urban water management practices for Busan Eco Delta city, a Semulmeori waterfront area in Gangseo district, Busan. The evaluation and scoring process was presented and established, serving as the basis for the application of the smart water city certification all over the world. The established guideline will be used to analyze future cities, providing integrated and comprehensive information on the status of their urban water cycle, gathering new techniques and proposing solutions for smarter measures.

• Journal of Advanced Navigation Technology
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• v.27 no.3
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• pp.300-305
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• 2023

In this paper, we confirmed that an efficient sensor network can be established at a low cost by applying Geofencing technology to a LoRa-based sensor network and verified its effectiveness in disaster management such as forest fires. We detected changes through GPS, gyro sensors, and combustion detection sensors, and defined the validity size of the Geofencing cell accurately. We proposed a LoRa Payload Frame Structure that has a flexible size according to the size of the sensor information.

• KNOM Review
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• v.22 no.3
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• pp.25-30
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• 2019

For meteorological applications, meaningful results must be derived and provided within time and resource limits. Forecasts through numerous historical data are time-consuming and still have resource limitations in the case of disaster safety-related analyses/predictions such as local typhoon forecasts. Suitable forecasts should be provided without any problems caused by limited physical environmental conditions and when results are to be drawn under time constraints, such as typhoon forecasts and forecast services for flooded areas by road. In this paper, we analyze the application of weather and climate forecasting to provide a suitable forecasting service in both temporal and resource conditions. Through the analysis of execution time according to mesh sizes, it was confirmed that a mesh adjustment can cope with the case of the temporal constraint. In addition, by analyzing the execution time through memory resource control, we confirmed the minimum resource condition that does not affect the performance and the resource usage pattern of the application through the swap and mlock analysis.

• Journal of Information Technology Services
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• v.22 no.2
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• pp.71-92
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• 2023

Globally, under the leadership of advanced ICT countries, the private sector is promoting various policies to promote the digital transformation of public services. Looking at the research trend, design of public service indicators, development of evaluation system, and empirical research are being carried out steadily, but there are insufficient research cases on models in which the private sector participates in the planning, development, and operation of public services. In this study, Private-centric digital public service suitability evaluation indicators were discovered through interviews with experts in various fields, and weights for each indicator were analyzed through AHP evaluation. In addition, by applying the analysis results to 18 digital public services on a trial basis, the importance and priority of evaluation indicators for each service were derived, and at the same time, the evaluation framework was designed and applied to diagnose implications. As a result of the study, 'social utility', 'corporate acceptability', and 'public acceptability' were selected as the top three indicators of suitability evaluation. At this time, it was analyzed that the weight of the 'company acceptability' index, which includes sub-indices such as 'service profitability', 'service scalability', and 'private initiative possibility', was the highest among the three top indicators. As a result of the demonstration for public services, "IoT facility unmanned remote monitoring service", "blockchain real estate transaction service", and "digital twin disaster prediction service" were evaluated as the most suitable public services for the transition to the private sector.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.203-203
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• 2020

동해안에 위치한 영동지역은 산지로 둘러싸여 있어 지형적인 여건으로 지상강우관측망의 밀도가 낮으며, 지상관측소의 관측한계를 보완하기 위해 사용되고 있는 기존 대형 레이더는 지형 차폐로 인해 영동지역에서는 정확한 강우정보를 관측하기 어렵다. 강우정보는 홍수예측을 위해 필수적인 정보이므로, 집중호우와 태풍으로 인한 홍수재해가 빈번히 발생하는 영동지역에서는 관측공백의 해소가 필요하다. 이를 위해 환경부에서는 동해안 지역에 2기의 전파강수관측소를 설치, 운영 중에 있다. 해당 관측소 자료는 30km 관측반경 범위 내에서 수 백 미터 이하의 격자 강우자료를 생산할 수 있는 장점이 있다. 본 연구에서는 전파강수관측소의 자료를 강우 및 홍수 재해정보 생산에 활용하고자 한다. 대상지역은 영동지역에 위치한 삼척오십천으로 해당 지역은 친수적으로 조성되어 강우로 인한 시민의 인명피해가 위험이 존재하는 곳이다. 본 연구에서는 새로 설치된 삼척 전파강수관측소로 관측된 자료를 이용하여 고해상도 격자 및 유역평균강우정보를 생산하고, 지역특성을 반영하여 강우정보 기반으로 하천홍수 위험을 판단할 수 있는 하천흐름계산도표를 개발하여 평가하고자 한다. 생산된 고해상도 격자 강우자료는 70m 격자 해상도를 갖으며, 분포형 비차등위상차를 이용하여 추정된 강우정보이다. 유역평균강우는 삼척오십천 유역과 삼척시 동단위 행정구역별로 산출된다. 또한 하천흐름계산도표는 삼척오십천 유역의 현장답사를 통해 시민의 접근성, 하천수위 급상승으로 인한 피해가능성을 고려하여 6개 지점을 선정하여 개발하고, 전파강수관측소 관측강우정보를 활용하여 홍수예측정보로의 적절성을 평가한다.

• Journal of Radiation Protection and Research
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• v.48 no.2
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• pp.68-76
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• 2023

Background: In the process of discussion on the possibility of using radionuclide-contaminated soil and debris generated by radiation disasters, a strategy for the proper management of radiation exposure protection while considering the source of the contaminated materials is necessary. Materials and Methods: The radiological protection criteria that are likely to be applied to the source-related approach based on the International Commission on Radiological Protection recommendations and the International Atomic Energy Agency safety standards are summarized. We proposed five interpretations of radiation protection to contribute to the promotion of discussion on the possibility of using a part of low-level-radionuclide-contaminated soil and debris in the post-accident rehabilitation. Interpretations I to III are based on the idea of "using a reference level to protect the public in post-accident rehabilitation," whereas IV and V are based on the idea of "using the dose constraint to protect the public in the post-accident rehabilitation when the sources are handled in a planned activity." The former idea is subdivided into three based on the definition of the source, which is managed by the reference level, and the latter idea is divided into two depending on whether or not additional dose from using contaminated materials is deemed acceptable. Results and Discussion: To confirm the applicability of the five interpretations presented, we suggested the concrete values of protection criteria via two feasible cases. In this case study, we proposed radiation protection by the dose constraint based on the Interpretation IV and chose 1 mSv/yr for the public and 20 mSv/yr for workers dealing with radionuclide-contaminated materials. Conclusion: We concretely and systematically demonstrated how the concept of radiation protection can be applied to the process of discussion on the possibility of using radionuclide-contaminated materials within the framework of an international system of protection. This study's findings can provide necessary information to discuss the possibility of using radionuclide-contaminated materials as an alternative option for recovery and reconstruction after a radiation disaster from the viewpoint of radiation protection.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6B
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• pp.605-612
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• 2006

In this study(II), The developed rainfall forecast model was applied to the NakDong River Basin for the heavy rainfall on 6th to 16th of August in 2002. The results demonstrated that the rainfall forecasts of 3 hours lead time showed good agreement with observed data. The inundation aspect of simulation depends on actual levee failure in the same basin. Rainfall forecasts were used for flood amount computation in the target watershed. Also the flood amount in the target watershed was used on boundary condition for flood inundation simulation in a protected lowland and a river. The results of simulation are consistent with actuality inundation traces and flood level data of the target watershed. This study provides practical applicability of satellite data in rainfall forecast of extreme events such as heavy rainfall or typhoon. Also this study presented an advanced integrated model of rainfall, runoff, and inundation analysis which can be applicable for flood disaster prevention and mitigation.

• Geomechanics and Engineering
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• v.34 no.2
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• pp.155-171
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• 2023

Aiming at the grouting treatment of water inflow in karst conduits, a visualized experiment system for conduit-type grouting blocking was developed. Through the improved water supply system and grouting system, and the optimized multisource information monitoring system, the real-time observation of diffusion and deposition of slurry, and the data acquisition of pressure and velocity during the whole process of grouting were realized, which breaks through the problem that the monitoring element is easy to fail due to slurry adhesion in conventional test system. Based on the grouting experiments in static and flowing water, the diffusion and deposition behavior of the quick-setting slurry under different working conditions were analyzed. The temporal and spatial variation behavior of the pressure and velocity were studied, and the blocking mechanism of the grouting were further revealed. The results showed that: (1) Under the flowing water condition, the counter-flow diffusion distance of slurry was negatively correlated with the flow water velocity and the volume ratio of cement and sodium silicate (C-S ratio), and positively correlated with the grouting volume. The slurry deposition thickness was negatively correlated with the flowing water velocity, and positively correlated with the grouting volume and C-S ratio. (2) The pressure increased slowly before blocking of the flowing water and rapidly after blocking in karst conduits. (3) With the continuous progress of grouting, the flowing water velocity decreased slowly first, then significantly, and finally tended to be stable. According to the research results, some engineering recommendations were put forward for the grouting treatment of the conduit-type water inflow disaster, which has been successfully applied in the treatment project of the China Resources Cement (Pingnan) Limestone Mine. This study provided some guidance and reference for the parameter optimization of grouting for the treatment projects of water inflow in karst conduits.