• Journal of Korea Water Resources Association
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• 제53권7호
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• pp.469-480
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• 2020

This study analyzed the differences of mean basin precipitation between TM and radar based on the 51 standard basins in Han river and Nakdong river when large scale of heavy rains occurred in 2018. The result shows that the differences between radar and TM are -65.05 ~ 26.09% and -82.00 ~ 3.80% for accumulated and 10 min. maximum mean basin precipitation, respectively. The correlation analysis between the differences of estimated mean basin precipitation and basin characteristics such as average altitude of basin, area of basin, and shape factor of basin presents that there is no clear correlation between them. And the differences of point precipitation also shows the similar tendency with those of mean basin precipitation. In order to find out the correlation between them and meteorological conditions such as rainfall patterns, the reflectivity of radars according to the observation angles is analyzed at the selected basins, and then it is found that the differences of mean basin precipitation between TM and radar is more dominated by the meteorological conditions than by the topographic conditions such as basin characteristics.

• Journal of Korean Tunnelling and Underground Space Association
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• 제19권1호
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• pp.71-82
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• 2017

It is necessary to conduct a detailed geotechnical investigation on the tunnel section in order to secure the tunnel design and construction stability. It is necessary for the importance of geotechnical investigation that needed for the analysis of distribution and size of fractured fault zone and distribution of groundwater in tunnel. However, if it is difficult to perform the ground survey in the tunnel design due to ground condition of the tunnel section and the limited conditions such as civil complaint, the tunnel design is performed using the result of the minimum survey. Therefore, if weathered fault zone exists in the face the reinforcement method is determined in the design process to secure the stability of the tunnel. The most important factor in reinforcing the tunnel excavation surface is to secure the stability of the tunnel by performing quick reinforcement. In particular, if groundwater leaching occurs on the excavation surface, more rapid reinforcement is needed. In this study, fractured fault zone exists on the tunnel excavation surface and displacement occurs due to weathered fracture zone. When the amount of groundwater leaching rapidly increased under the condition of displacement, the behavior of tunnel displacement was analyzed based on tunnel collapse. In the study, reinforcement measures were taken because the first stage displacement did not converge continuously. After the first reinforcement, the displacement was not converged due to increased groundwater leaching and the second stage displacement occurred and chimney collapse occurred.

• Journal of Korea Water Resources Association
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• 제50권5호
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• pp.315-324
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• 2017

In this study, the HEC-GeoRAS model was used to estimate the changes of flood inundation depth and area of the Hyeoam-cheon basin after the channel migration and river improvement. The target area was extremely damaged due to the heavy rainfall on 25th August, 2014 after the costruction. According to the results of the analysis, the HEC-GeoRAS model can be used to accurately estimate the changes of flood innundation depth and area in agrecultural lands and lowlands of which the topographic changes and elevation differences are small. The inundation depths were increased 0.99 m in heavy rainfall and 0.39 m in 100 year frequency flood. The inundation areas in 100 year frequency flood were reduced in inundation depths under 1.5 m while they were increased in depths above 4.5 m. It was concluded that the loss of natural resevoir capacity of agricultural lands and lowlands due to the channel migration and river improvement caused the damage of flood in 2014 and the decrease of actual effective widths of the channel added the damage.

• Journal of Korea Water Resources Association
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• 제48권7호
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• pp.581-593
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• 2015

This study constructs the drought outlook system using ESP(Ensemble Streamflow Prediction) method and evaluates its utilization for drought prediction. Historical Runoff(HR) was estimated by employing LSM(Land Surface Model) and the observed meteorological, hydrological and topographical data in South Korea. Also Predicted Runoff(PR) was produced for different lead times(i.e. 1-, 2-, 3-month) using 30-year past meteorological data and the initial soil moisture condition. The HR accuracy was higher during MAM, DJF than JJA, SON, and the prediction accuracy was highly decreased after 1 month outlook. SRI(Standardized Runoff Index) verified for the feasibility of domestic drought analysis was used for drought outlook, and PR_SRI was evaluated. The accuracy of PR_SRI with lead times of 1- and 2-month was highly increased as it considered the accumulated 1- and 2-month HR, respectively. The Correlation Coefficient(CC) was 0.71, 0.48, 0.00, and Root Mean Square Error(RMSE) was 0.46, 0.76, 1.01 for 1-, 2- and 3-month lead times, respectively, and the accuracy was higher in arid season. It is concluded that ESP method is applicable to domestic drought prediction up to 1- and 2-month lead times.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제17권6호
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• pp.408-417
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• 2016

The frequent regional torrential or heavy rain and typhoon mostly caused by climate change has resulted in sediment disasters particularly in mountainous or hilly areas. More than 65% of South Korea is mountainous and development and rapid urbanization has brought lots of steep sloping industrial complexes, which are adjacent to cities. Such continuous urbanization and industrialization can result in an increase in serious damage to those places. Korea has very high population density so sediment disaster could result in a tremendous loss of property and life. A recent 10-year (2001~2010) study of the average annual loss shows 68 casualties and property loss of 1.7044 trillion Won(?), which indicates a 20% and 25% decrease for both life and property, respectively, but urban areas are experiencing increasing damage. In this paper, a comprehensive simulator composed by references, analyses, and the recent technologies was applied to visualize the scale of the damaged Woomyeon-san (Mt.) and verify the performance of the simulator.

• Journal of the Korean Geosynthetics Society
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• 제14권4호
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• pp.79-86
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• 2015

Korean territories has formed about 70% of mountainous areas that have acidified serious level to average pH 4-5. There are a number of abandoned metal mines about 1,000 in Korea. However, mine tailings and waste rock included heavy metals are exposed to long-term environment without prevention facility or treatment system. Thus, ongoing management and monitoring of soil environment are required. Most of abandoned mine scattered in forest areas of slopes. Soil erosion due to continuous rainfall in the slopy areas can cause the secondary pollution by the influence eutrophication of water system and the productivity loss of the plant. Therefore, this study would like to estimate pH leaching rate by artificial rainfall using waste neutralization-agent in lysimeter. Moreover, the potentially of secondary pollution related to precipitation is figured out through the experiments, and the optimal planting methods would examinate after neutralizing treatment in soil. Experiments composed three kinds of lysimeter; lysimeter 1 had filled only acidic soil, lysimeter 2 had neutralized soil, and lysimeter 3 had planting plants after neutralized soil. In the results, lysimeter 2 showed the lowest pH leaching, and there is not specific relativity with pH leaching of the seasonal characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제16권12호
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• pp.8879-8888
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• 2015

When the disaster like earthquake in urban area occur, due to the collapse accidents for subway, tunnel space with buildings or underground area, enormous property and human damage are happened. Specially, since it is difficult to identify survived status of humans within collapsed debris and accurately buried locations of the humans, inputs of considerable time and manpower for rescuing them are required. Besides, secondary damage can be occurred by additional collapses. The aim of this study is to propose a stochastic location positioning method that enables to provide aid information by determining locations of mobile devices for buried persons in 2-D plane using wireless communication technologies. This study selected a detection method for buried persons based on Wi-Fi signal, and identified characteristics of signal strengths by distance unit. Using these methods, a stochastic location detection model in 2-D plane was built. It is expected that this technology will be utilized as a core technology that can protects safety and human life of the public by providing data for rescuing quickly buried persons in cases of national disasters for future.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 한국항해항만학회 2010년도 춘계학술대회
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• pp.135-138
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• 2010

IMO adopt the revision of SOLAS convention on requirement systems for ECDIS and considered an ECDIS as the major system for E-Navigation strategy on marine transportation safety and environment protection. ENC(Electronic Navigational Chart) as base map of ECDIS is considered as a principal information infrastructure that is essential for navigation tasks. But ENCs are not easy to utilize because they are encoded according to ISO/IEC 8211 file format, and ENCs is required to utilize in parts of Marine GIS and various marine application because they are used for navigational purpose mainly. Meanwhile Google earth is satellite map that Google company service, is utilized in all kinds of industry generally providing local information including satellite image, map, topography, 3D building information, etc. In this paper, we developed KML conversion technology for ENC application. details of development contents consist of ENC loading module and KML conversion module. Also, we applied this conversion technology to Korea ENC and evaluated the results.

• Journal of Korea Water Resources Association
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• 제39권8호
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• pp.669-676
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• 2006

Hydrological factors, especially the spatial distribution of interpretation on precipitation is often topic of interest in studying of water resource. The popular methods such as Thiessen method, inverse distance method, and isohyetal method are limited in calculating the spatial continuity and geographical characteristics. This study was intended to overcome those limitations with improved method that will yield higher accuracy. The monthly and yearly precipitation data were produced and compared with the observed daily precipitation to find correlation between them. They were then used as secondary variables in Co-kriging method, and the result was compared with the outcome of existing methods like inverse distance method and kriging method. The comparison of the data showed that the daily precipitation had high correlation with corresponding year's average monthly amounts of precipitation and the observed average monthly amounts of precipitation. Then the result from the application of these data for a Co-kriging method confirmed increased accuracy in the modeling of spatial distribution of precipitation, thus indirectly reducing inconsistency of the spatial distribution of hydrological factors other than precipitation.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 3부
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• pp.854-858
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• 2006

디지털화의 가속, 고속 통신 인프라의 확대 등으로 전자, 정보 통신 기기들이 단일 네트워크로 연결되어 영상 및 음향 정보를 서로 공유할 수 있으며, 생활 공간 내에서 실생활의 질 향상을 위한 지능적 정보 서비스와 자연스럽고 편한 내추럴 인터페이스 기술에 의한 지능형 반응 정보 서비스 공간 기술이 중요한 이슈로 등장하고 있다. 본 연구에서는 지능형 반응 공간의 물리적 객체로서 학교, 연구 기관 및 회사 등의 회의실을 선정한다. 그리고, 이를 대상으로 회의 참여자들이 자연스럽고 편리하게 의견 교환, 관련 자료 및 정보 처리를 할 수 있는 시스템 구축을 위한 아키텍처에 대하여 논의한다. 본 연구에서 제안하는 시스템 아키텍처는 회의와 관련된 문서나 회의 내용 등의 정보를 실감 가시화 노드로 추상화되고 메타 정보화함으로써 전체 회의 내용의 파악과 회의 정보에 대한 체계적이고 논리적인 관리를 가능하게 한다. 또한 여러 사람의 공동 작업을 필요로 하는 정보 또는 문서에 대한 동시 편집 기능과 자연스러운 동작에 의한 데이터 조작을 지원하는 실감 워크벤치 및 워크스크린 기술, 정보 핸들링의 다양성과 조작의 편리성을 위한 실감 아이콘에 의하여 자연스럽고 편리한 회의를 가능하게 한다. 그리고, 이러한 요소 기술들이 에이전트에 의해 회의 프로세스 및 요소 기술들의 시스템적 통합을 가능하게 한다.