• Title/Summary/Keyword: Urban environmental problem

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Design Development of Street Furniture for Improvement of Urban Environment - Focusing on "Y" District, a part of the Seoul Design Street Project -

  • Kim, Kook-Sun
    • Journal of the Korea Furniture Society
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    • v.20 no.6
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    • pp.581-589
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    • 2009
  • Under 'The Design Street' Project, one of the urban environment improvement projects of Seoul, the facilities on the street have been greatly varied in terms of design. In addition, the municipal authority has pushed each district to develop its own identity based on the integrated design of the city. This study was aimed to propose a design which could solve the current problem in street furniture in terms of environmental improvement through an analysis on current street conditions in "Y" District as a part of Seoul Design Street Project. It has attempted to propose 11 street furnitures based on the basic strategy of 'Soft City' which has been promoted by Seoul City in accordance with the Seoul Public Facility Guidelines as 1. Airy Design, 2. Integrated Design, 3. Collaborative Design and 4. Sustainable Design. Among them, for the total design in Seoul six facilities - kiosk, manhole, traffic signal controller, public phone, road sign and waste receptacle were proposed by Seoul City have been accepted. For local differentiation, on the contrary, five items - planter bench, bollard, lifter, bike rack and fence have been newly designed and proposed. Furthermore, it is essential to carry out systematic supervision and continuous management on the detail design and construction of current regional design development projects.

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A New Control Technique of Drainage Pump Based on Fuzzy Control (퍼지제어기법을 사용한 우수배제 펌프의 조작기법 개발)

  • Lee, Won Hwan;Cho, Won Cheol;Shim, Jae Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.3
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    • pp.107-114
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    • 1992
  • With the increasing of impervious area and shortening of travel time, the risk of flooding in urban area becomes a serious problem in Seoul metropolitan area, and its alternatives are needed. In this study, one of urban flood alternatives, a fuzzy control technique is applied in pumping station to test its drainage capacity of inland inflow, and compared with existing pumping criteria (controled by water level). Three design rainfalls(10, 30, and 50 year) are applied to ILLUDAS model to calculate inflow in detention reservoir. To check the efficiency of fuzzy control, two fuzzy rules are used in the operation of pumping station. In these results, fuzzy control rules, based on the experiences of experts, show applicability in practice and effectiveness in inland flooding prevention.

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Application and Comparison of Dynamic Artificial Neural Networks for Urban Inundation Analysis (도시침수 해석을 위한 동적 인공신경망의 적용 및 비교)

  • Kim, Hyun Il;Keum, Ho Jun;Han, Kun Yeun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.5
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    • pp.671-683
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    • 2018
  • The flood damage caused by heavy rains in urban watershed is increasing, and, as evidenced by many previous studies, urban flooding usually exceeds the water capacity of drainage networks. The flood on the area which considerably urbanized and densely populated cause serious social and economic damage. To solve this problem, deterministic and probabilistic studies have been conducted for the prediction flooding in urban areas. However, it is insufficient to obtain lead times and to derive the prediction results for the flood volume in a short period of time. In this study, IDNN, TDNN and NARX were compared for real-time flood prediction based on urban runoff analysis to present the optimal real-time urban flood prediction technique. As a result of the flood prediction with rainfall event of 2010 and 2011 in Gangnam area, the Nash efficiency coefficient of the input delay artificial neural network, the time delay neural network and nonlinear autoregressive network with exogenous inputs are 0.86, 0.92, 0.99 and 0.53, 0.41, 0.98 respectively. Comparing with the result of the error analysis on the predicted result, it is revealed that the use of nonlinear autoregressive network with exogenous inputs must be appropriate for the establishment of urban flood response system in the future.

Sewer overflow simulation evaluation of urban runoff model according to detailed terrain scale (상세지형스케일에 따른 도시유출모형의 관거월류 모의성능평가)

  • Tak, Yong Hun;Kim, Young Do;Kang, Boosik;Park, Mun Hyun
    • Journal of Korea Water Resources Association
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    • v.49 no.6
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    • pp.519-528
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    • 2016
  • Frequently torrential rain is occurred by climate change and urbanization. Urban is formed with road, residential and underground area. Without detailed topographic flooded analysis consideration can take a result which are wrong flooded depth and flooded area. Especially, flood analysis error of population and assets in dense downtown is causing a big problem for establishments and disaster response of flood measures. It can lead to casualties and property damage. Urban flood analysis is divided into sewer flow analysis and surface inundation analysis. Accuracy is very important point of these analysis. In this study, to confirm the effects of the elevation data precision in the process of flooded analysis were studied using 10m DEM, LiDAR data and 1:1,000 digital map. Study area is Dorim-stream basin in the Darim drainage basin, Sinrim 3 drainage basin, Sinrim 4 drainage basin. Flooding simulation through 2010's heavy rain by using XP-SWMM. Result, from 10m DEM, shows wrong flood depth which is more than 1m. In particular, some of the overflow manhole is not seen occurrence. Accordingly, detailed surface data is very important factor and it should be very careful when using the 10m DEM.

Particle Separation Characteristics and Harvesting Efficiency of Spirulina platensis Using Micro-bubble (미세기포를 이용한 Spirulina platensis의 입자 부상분리 특성 및 수거효율)

  • Gwak, Gyu-Dong;Kim, Mi-Sug;Kwak, Dong-Heui
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.5
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    • pp.621-629
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    • 2013
  • Since algae had been issued an environmental problem, water blooms, deepened due to increase of retention water basin in Korea as well as a biomass resource for producing biofuel, this study conducted a series of experiments for Spirulina platensis using the flotation process with micro-bubble. To elevate utilization of collected-algae, this study focused on omitting or minimizing coagulant's doses as changing a cultivation period and condition affected on physical property change of algae. Two coagulants, PAC and Chitosan, were used to test the collecting rate of algae and the result found no difference between two rates. For flotation experiments without adding the coagulant, dried algae weight (passing 14 days after cultivation for 20 days) detected high separation efficiency 98.2 % and it (passing 7 days after long-term cultivation for 28 days) presented good separation efficiency 91.9 %. Chlorophyll's separation efficiency showed a similar tendency with the case of the dried algae weight. In endogeny conditions, a light source and a carbon source were not considerably affected on the flotation separation efficiency. Thus, this study confirms that algae biomass may be collected without the coagulant during the endogeny condition period after enough cultivation time, 3 weeks.

Study on Multi-vehicle Routing Problem Using Clustering Method for Demand Responsive Transit (수요응답형 대중교통체계를 위한 클러스터링 기반의 다중차량 경로탐색 방법론 연구)

  • Kim, Jihu;Kim, Jeongyun;Yeo, Hwasoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.5
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    • pp.82-96
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    • 2020
  • The Demand Responsive Transit (DRT) system is the flexible public transport service that determines the route and schedule of the service vehicles according to users' requests. With increasing importance of public transport systems in urban areas, the development of stable and fast routing algorithms for DRT has become the goal of many researches over the past decades. In this study, a new heuristic method is proposed to generate fast and efficient routes for multiple vehicles using demand clustering and destination demand priority searching method considering the imbalance of users' origin and destination demands. The proposed algorithm is tested in various demand distribution scenarios including random, concentration and directed cases. The result shows that the proposed method reduce the drop of service ratio due to an increase in demand density and save computation time compared to other algorithms. In addition, compared to other clustering-based algorithms, the walking cost of the passengers is significantly reduced, but the detour time and in-vehicle travel time of the passenger is increased due to the detour burden.

Conservation Value Assessment by Considering Patch Size, Connectivity and Edge (패치크기, 연결성, 가장자리를 고려한 보전가치평가)

  • Lee, Dong-Kun;Kim, Eun-Young;Oh, Kyu-Shik
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.5
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    • pp.56-67
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    • 2005
  • Rapid and reckless economical development is causing nationwide deforestation; more and more forest is being developed to be used as a base for economic advancement. While benefiting the national economy, this destruction of forest is creating a serious problem in the National Land Plan. To solve this problem, it is imperative to understand the current condition of damaged forest and make an environment-friendly plan. This paper explains the principles of spatial plan and sets the criteria for the plan, such as patch size, connectivity, and edge of the Landscape Ecology. The paper assesses the conservational value of area that are currently being developed or planned to be developed to figure out the current environmental situation. This conservational value was verified by the field survey. The result of assessment appears that the patch size of the major mountains in site is over 1,000ha and edge is located widely beside roads. The area of the high connectivity is located agriculture area in valley or narrow roads. The research shows that the patch size is related to biodiversity the larger the patch size, the more populated the species are. The research also reveals the conservational value indicated by degree of connection to forest, difference in the structure of vegetation between core area and edge area, and effects of surrounding environment. In further study, we will assess other criteria of conservation value, such as patch shape and fragmentation to the Landscape Ecology, and apply those criteria in biological aspects of the spatial plan.

Zoning Permanent Basic Farmland Based on Artificial Immune System coupling with spatial constraints

  • Hua, Wang;Mengyu, Wang;Yuxin, Zhu;Jiqiang, Niu;Xueye, Chen;Yang, Zhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.5
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    • pp.1666-1689
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    • 2021
  • The red line of Permanent Basic Farmland is the most important part in the "three-line" demarcation of China's national territorial development plan. The scientific and reasonable delineation of the red line is a major strategic measure being taken by China to improve its ability to safeguard the practical interests of farmers and guarantee national food security. The delineation of Permanent Basic Farmland zoning (DPBFZ) is essentially a multi-objective optimization problem. However, the traditional method of demarcation does not take into account the synergistic development goals of conservation of cultivated land utilization, ecological conservation, or urban expansion. Therefore, this research introduces the idea of artificial immune optimization and proposes a multi-objective model of DPBFZ red line delineation based on a clone selection algorithm. This research proposes an objective functional system consisting of these three sub-objectives: optimal quality of cropland, spatially concentrated distribution, and stability of cropland. It also takes into consideration constraints such as the red line of ecological protection, topography, and space for major development projects. The mathematical formal expressions for the objectives and constraints are given in the paper, and a multi-objective optimal decision model with multiple constraints for the DPBFZ problem is constructed based on the clone selection algorithm. An antibody coding scheme was designed according to the spatial pattern of DPBFZ zoning. In addition, the antibody-antigen affinity function, the clone mechanism, and mutation strategy were constructed and improved to solve the DPBFZ problem with a spatial optimization feature. Finally, Tongxu County in Henan province was selected as the study area, and a controlled experiment was set up according to different target preferences. The results show that the model proposed in this paper is operational in the work of delineating DPBFZ. It not only avoids the adverse effects of subjective factors in the delineation process but also provides multiple scenarios DPBFZ layouts for decision makers by adjusting the weighting of the objective function.

Review on the Three-Dimensional Inversion of Magnetotelluric Date (MT 자료의 3차원 역산 개관)

  • Kim Hee Joon;Nam Myung Jin;Han Nuree;Choi Jihyang;Lee Tae Jong;Song Yoonho;Suh Jung Hee
    • Geophysics and Geophysical Exploration
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    • v.7 no.3
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    • pp.207-212
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    • 2004
  • This article reviews recent developments in three-dimensional (3-D) magntotelluric (MT) imaging. The inversion of MT data is fundamentally ill-posed, and therefore the resultant solution is non-unique. A regularizing scheme must be involved to reduce the non-uniqueness while retaining certain a priori information in the solution. The standard approach to nonlinear inversion in geophysis has been the Gauss-Newton method, which solves a sequence of linearized inverse problems. When running to convergence, the algorithm minimizes an objective function over the space of models and in the sense produces an optimal solution of the inverse problem. The general usefulness of iterative, linearized inversion algorithms, however is greatly limited in 3-D MT applications by the requirement of computing the Jacobian(partial derivative, sensitivity) matrix of the forward problem. The difficulty may be relaxed using conjugate gradients(CG) methods. A linear CG technique is used to solve each step of Gauss-Newton iterations incompletely, while the method of nonlinear CG is applied directly to the minimization of the objective function. These CG techniques replace computation of jacobian matrix and solution of a large linear system with computations equivalent to only three forward problems per inversion iteration. Consequently, the algorithms are efficient in computational speed and memory requirement, making 3-D inversion feasible.

Development of Urban Competitiveness Evaluation Index on Facility Layout of Multi-dimensional Development of Farilway Facility Site (철도시설부지 입체개발의 시설 배치에 대한 도시경쟁력 평가지표 개발)

  • Kang, Youn Won;Kim, Jong Gu;Shin, Eun Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.4
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    • pp.587-593
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    • 2024
  • Recently, countries such as Japan and France are actively using three-dimensional development of land to secure available land. In Korea, too, the lack of available land within cities is a major problem, and in particular, the problem of decline due to disconnection due to division due to the railroad is emerging. As a solution to this, interest in three-dimensional development is increasing day by day, but the application or legal effectiveness of the concept is still lacking. Therefore, in this study, assuming that the Gyeongbu Line railway in Busan is underground, we attempted to apply the type of multi-dimensional development appropriate for each region to the land that would be created, and to predict how much it would contribute to urban competitiveness by arranging the necessary facilities for each part. To this end, we have developed an urban competitiveness index that can evaluate the layout of facilities by region, and since the range of the region is different from the existing evaluation indicator, it is judged that the three-dimensional development of the railway facility site can have a positive impact on the competitiveness of the city as a result of the prediction through a subjective survey.