• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.424-424
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• 2021

서울시 전역의 하수관로는 4개의 처리구역, 16개의 배수구역, 163개의 배수분구, 748개의 소구역으로 분할하여 관리되고 있다. 하지만 지선관로와 간선관로가 상이한 설계빈도로 계획되어 가장 작은 관리단위인 소구역에서도 일정한 방재성능을 기대하기 어려운 실정이다. 따라서 본 연구에서는 소구역을 동일한 토출구를 갖는 유역으로 재정의하여 서울시 전역을 799개의 소구역으로 재분할한 후, 소구역 단위로 하수관로 방재성능을 분석하였다. 서울시 하수관로 방재성능 분석을 위해 도시유출모형은 SWMM, 도시침수모형은 2DIS를 활용하였다. 도시유출모형에서는 113,286개의 관로와 106,097개의 맨홀을 적용하였으며, 수리시설물은 서울시 관내에 위치한 31개의 모든 빗물저류조와 121개의 빗물펌프장 중 가용 가능한 117개의 빗물펌프장을 적용하였다. 하수관로의 외수위 경계조건은 하천기본계획에서 제시한 방류하천의 기점홍수위를 반영하였다. 도시침수모형에서는 5m 단위의 고해상도 지형자료와 토지피복도를 적용하여 2차원 침수모의를 수행하였으며, 799개의 소구역에 대한 방재성능 분석을 수행하여 이를 시스템에 적용하였다. 서울시 하수관로 방재성능 분석 시스템에서는 799개의 소구역을 대상으로 소구역 정보, 하수관로 정보, 수방시설물 정보, 방재성능 정보를 제공하고 있다. 소구역 정보는 해당 소구역에 대한 기본 정보 및 해당 소구역에 위치한 수리시설물에 대한 기본 정보를 제공한다. 하수관로 정보에서는 관로 및 맨홀을 선택하여 상세정보를 확인할 수 있다. 수방시설물 정보에서는 빗물펌프장, 빗물저류조, 강우관측소, 하천수위관측소, 관로수위관측소에 대한 상세정보를 제공한다. 마지막으로 방재성능 정보에서는 시나리오별 침수결과를 제공하며, 포인트 단위 침수취약지역을 표출한다. 서울시 하수관로 방재성능 분석 시스템은 하수도 정책 입안과 하수도 관련 사업 추진 시 데이터 기반의 신속하고 효율적인 의사결정 업무를 지원할 수 있을 것으로 기대된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3B
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• pp.311-317
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• 2009

Similarity indices between sampling sites are calculated and cluster analysis of fish community is carried out by UPGMA based on investigating fish fauna and water environment. The restoration indicators as target species of Wonju stream are selected Cottus poecilopus, Zacco temmincki, and Zacco platypus along upper, middle, and lower streams, respectively. For better habitat suitability, low flow increasing and induced water quality improving must be secured by sewer system rearrangement and watershed management. Composite habitat suitability of Zacco temmincki as target species at middle stream of Wonju stream improve significantly by low flow increasing, which is very important factor to improve habitat suitability. The changes of hydraulics of depth and velocity govern the habitat suitability in general, but the effects are not significant. Low flow increasing with the change of 10% reducing of lower channel improves the composite habitat suitability of 0.37~0.78 to their origin of 0.1~0.25, which represent the channel restoration scheme of Wonju stream for enhancing the habitat suitability of fish community.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.392-392
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• 2022

세계적 규모의 팬데믹 감염병의 출현은 전 세계적으로 경제적, 문화적, 사회적 파급효과가 매우 강력하며 전 인류를 위협하고 있다. 최근에 발병한 중증급성 호흡기질환 코로나바이러스 2(Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2)는 2019년 12월 중국 우한에서 첫 보고 되었고 2022년 현재까지 종식되지 않고 있으며 바이러스의 전파력과 치명률이 높고 무증상 감염상태일 때에도 전염이 가능하여 현재 역학조사의 사후적 대응에 대한 한계가 있어 선제적 대응을 위한 수단이 필수 불가결해지고 있는 실정이다. 하수기반역학(Waste Based Epidemiology, WBE)이란 하수처리장으로 유입되기 전의 하수를 분석하여 하수 집수구역 내 도시민의 생활상을 예측하는 것으로 하수로 배출된 감염자의 분비물 및 배설물 속 바이러스를 하수관로에서 신속하게 검출함으로써 특정지역의 감염성 질환 전파 정도와 유행하는 타입(변이)등을 분석하고 기존 역학조사의 문제점을 극복할 수 있으며 선제적인 대응이 가능하다. 현재 COVID-19의 대유행과 관련하여 WBE를 기반으로 한 다양한 연구가 진행되고 있으며 실제 환자의 발생과 상관관계가 있음이 확인되고 있고 백신 접종과 새롭게 발생한 변이바이러스의 관계 속에서 발생하는 변수를 고려한 모델이 없다는 점을 들어 새로운 감염병 확산 예측 모델에 대한 필요성 또한 커지고 있다. 본 연구에서는 병원에서부터 하수처리장까지의 하수관거와 하수처리장에서의 SARS-CoV-2 검출농도 및 거동을 파악하는 것을 목적으로 하고 있으며 COVID-19의 감염규모 확산에 관한 방법론에서 수학적모델 (Euler Method, RK4 Method, Gillespie Algorithm)과 딥러닝 기반의 Nowcasting model과 Fore casting model을 살펴보고자 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.301-301
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• 2022

최근 우리나라는 지속적으로 국지성 집중호우 발생빈도와 총강우량이 증가하고 있다. 서울시와 같이 대부분의 지역이 도심지로 구성되어 있는 경우, 하천범람으로 인한 홍수피해 뿐만 아니라 하수관로의 성능부족으로 인해 침수가 빈번하게 발생하고 있다. 이에 서울시에서는 피해를 최소화하고 대응수준 향상을 위해 침수지역 및 통수능 부족 관로 예측이 가능한 서울시 하수관로 성능관리 시스템을 개발하여 활용하고 있다. 서울시 하수관로 성능관리시스템에서는 유역특성과 방류구를 기준으로 결정한 603개 소유역 단위로 하수관로에 관한 다양한 정보를 제공한다. 시스템은 소유역, 하수관로, 수방시설물, 방재성능 메뉴로 구성되어 있다. 소유역 메뉴에서는 603개 소유역별 제원정보, 하수관로 및 수방시설물 개수, 관측소 개수 등의 정보를 제공하며, 하수관로 메뉴에서는 소유역 내 600mm 이상의 관로 및 맨홀에 대한 제원정보를 제공하고, 수방시설물 메뉴에서는 소유역 내 빗물펌프장, 빗물저류조, 관측소에 대한 제원정보를 제공한다. 또한, 방재성능 메뉴에서는 총강우량, 기점수위, 빗물받이효율을 반영한 40개 시나리오 기반의 관로 단위 통수능 정보와 소유역 단위 침수 정보를 제공한다. 방재성능 및 침수정보 제공을 위해 분석모델은 1차원 관망해석에 SWMM(Storm Water Management Model)과 2차원 침수해석에 2DIS(2Dimension Inundation Solution)를 활용하였다. 적용자료는 서울시 내 600mm 이상의 우수관로체계, 빗물펌프장, 빗물저류조 등 수방시설물고, 5m 단위 고해상도 지형자료를 적용하였다. 서울시 하수관로 성능관리시스템은 현재 서울시 현업에서 활용 중에 있으며, 지속적인 운영과 개선을 통해 추후에는 하수관로 운영 및 관리의 효율성 증대와 데이터에 근거한 하수관로 정책입안과 하수관로 관련사업 추진이 가능할 것으로 기대된다.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.55-69
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• 2011

Use of disposer at the kitchens of Korean apartments is inevitable in treating their foodwaste having a water content of more than 80%. Also we have to ensure that this extra disposer-foodwaste BOD loadings be treated properly by installing/operating a pre-treatment system before this wastewater enters public sewer system. However, the degree of BOD removal should not be excessive since a BOD/N ratio higher than 5 is required for removing N/P at a municipal wastewater treatment plant. The removal of BOD/N in the pretreatment system rather than BOD alone can be an alternative solution in solving this problem. The particles separated by sedimentation, screen or packed-bed can be anaerobically digested at apartment sites to generate biogas that can be used for simple digester heating and to generate volatile fatty acids (VFAs) for nitrogen removal. We suggest that Korean government grants a temporary license (say for 5 years) to foodwaste treatment companies in collaboration with apartment construction companies which may do business and develop various kinds of disposer-foodwaste treatment systems in diverse wastewater discharge systems of Korean apartments.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.13-26
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• 2015

Many urban areas in Korea suffer from repeated flood damage during intensive rainfall due to an increase in impervious areas caused by rapid urbanization and deteriorating sewage systems. A centralized stormwater management system has caused severe flood damage in an area that has proven unable to accommodate recent climate change and a rise in precipitation. Most flooding prevention projects that have been recently implemented focus on increasing drainage system capacity by expanding the size of sewer pipes and adding pumping stations in downstream areas. However, such measures fail to provide sustainable solutions since they cannot solve fundamental problems to reduce surface runoff caused by urbanization across the watershed. A decentralized stormwater management system is needed that can minimize surface runoff and maximize localized retention capacity, while maintaining the existing drainage systems. This study proposes a stormwater management corridor for the flood-prone watershed in the city of Dongducheon. The corridor would connect the upstream, midstream, and downstream zones using various methods for reducing stormwater runoff. The research analyzed surface runoff patterns generated across the watershed using the Modified Rational Method considering the natural topography, land cover, and soil characteristics of each sub-watershed, as well as the urban fabric and land use. The expected effects of the design were verified by the retainable volume of stormwater runoff as based on the design application. The results suggest that an open space network serve as an urban green infrastructure, potentially expanding the functional and scenic values of the landscape. This method is more sustainable and effective than an engineering-based one, and can be applied to sustainable planning and management in flood-prone urban areas.

• The KIPS Transactions:PartD
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• v.10D no.4
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• pp.591-602
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• 2003

Delay and discontinuance phenomenon of service are cause by sudden increase of the network communication amount and the quantity consumed of resources when Internet users are driven excessively to a conventional single large database sewer. To solve these problems, spatial database cluster consisted of several single nodes on high-speed network to offer high-performance is risen. But, research about spatial join operation that can reduce the performance of whole system in case process at single node is not achieved. So, in this paper, we propose efficient parallel spatial join processing method in a spatial database cluster system that uses data partitions and replications method that considers the characteristics of space data. Since proposed method does not need the creation step and the assignment step of tasks, and does not occur additional message transmission between cluster nodes that appear in existent parallel spatial join method, it shows performance improvement of 23% than the conventional parallel R-tree spatial join for a shared-nothing architecture about expensive spatial join queries. Also, It can minimize the response time to user because it removes redundant refinement operation at each cluster node.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10A
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• pp.886-895
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• 2005

As the networked media technology have been grown in recent, there have been many research works to deliver high-quality video such as HDV and HDTV over the Internet. To realize high-quality media service over the Internet, however, the network adaptive streaming scheme is required to adopt to the dynamic fluctuation of underlying networks. In this paper, we design and implement the network-adaptive HD(high definition) MPEG-2 streaming system employing the frame-based prioritized packetization. Delivered video is inputted from the JVC HDV camera to the streaming sewer in real-time. It has a bit-rate of 19.2 Mbps and is multiplexed to the MPEG-2 TS (MPEG-2 MP@HL). For the monitoring of network status, the packet loss rate and the average jitter are measured by using parsing of RTP packet header in the streaming client and they are sent to the streaming server periodically The network adaptation manager in the streaming server estimates the current network status from feedback packets and adaptively adjusts the sending rate by frame dropping. For this, we propose the real-time parsing and the frame-based prioritized packetization of the TS packet. The proposed system is implemented in software and evaluated over the LAN testbed. The experimental results show that the proposed system can enhance the end-to-end QoS of HD video streaming over the best-effort network.

• Journal of Korea Water Resources Association
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• v.40 no.3
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• pp.223-236
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• 2007

Recently in urban area flood damages increase due to local concentrated heavy rainfall. Even in the cities where stormwater drainage systems are relatively well established flood damage still occurs because of the capacity limitations of the existing stormwater drainage systems. When the flood exceeds the capacity limitation of the urban storm sewer system, it yields huge property losses of public facilities involving roadway inundation to paralyze industrial and transportation system of the city. To prevent such flood damages in urban area, it is necessary to develop adequate inundation analysis model which can consider complicated geometry of urban area and artificial drainage system simultaneously. The Dual-Drainage model used in this study is the urban inundation analysis model which combines SWMM with DEM based 2-dimensional surface flood inundation model. In this study, the dual drainage model has been modified to consider the effect of complex buildings in urban area. Through the simulation of time variable inundation process, it is possible to identify inundation alert locations as well as to establish emergency action plan for the residencial area vulnerable to flood inundation.

• Journal of Korea Water Resources Association
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• v.50 no.12
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• pp.877-887
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• 2017

The energy losses due to surcharged flow at four-way combining manhole, which is mainly installed in the downstream of urban sewer system, is the main cause of inundation in urban area. Surcharged four-way combining manholes form various flow configuration such as straight through, T-type, and four-way manholes depending on variation of inflow discharge in inlet pipes. Therefore, it is necessary to analyze change of energy loss and estimate head loss coefficients at surcharged four-way combining manhole with variation of inflow discharge ratio. The hydraulic experimental apparatus which can change inflow ratios were installed to analyze the flow characteristics at four-way combining manhole. In this study, to calculate the head loss coefficient according to change of the inflow discharge ratios at the surcharged four-way combining square manhole, the discharge conditions of 40 cases which the inflow ratios of each inlet pipe were changed by 10% interval was selected. The head loss coefficient at surcharged square manhole showed the lowest value of 0.40 at the straight manhole and the highest value of 1.58 at the $90^{\circ}$ junction manhole. In the combining manholes (T-type and four-way), the head loss coefficients were calculated more higher as the lateral flow rate was biased. The contour map of head loss coefficient range was constructed by using the estimated head loss coefficients and the empirical formula of head loss coefficients was derived to consider the variation of inflow discharge ratios at the surcharged square manhole. The empirical formula could be applied to the design and assessment of the urban drainage system.