• Journal of Korea Water Resources Association
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• v.33 no.S1
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• pp.415-421
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• 2000

• Environmental Engineering Research
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• v.15 no.1
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• pp.41-48
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• 2010

This paper describes the influence of nutrient salts eluted from the bottom of a closed water area where polluted sediment has been deposited by inflowing river water. The elution pattern was monitored at our experimental facility. Both the sediment pore water and water above the bottom were sampled using a dialyzer sampler (peeper). The pore water of the eutrophicated sediment contained a large amount of nutrient salts, and the effect of elution was confined to a limited area of the bottom surface. The nutrient concentration of the sediment pore water was closely related to both the water temperature and dissolved oxygen (DO) concentration. The eluted nutrients from the sediment provided a source for phytoplankton and algae growth. This experimental data indicated that the water quality of the surface was not directly connected to the eluted nutrient salts, while it was indirectly affected by the total ecosystem, including all the organisms within an area and their environment.

• Journal of Korean Society of Rural Planning
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• v.18 no.2
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• pp.69-79
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• 2012

This study was carried out to analyze the disparities of basic living infrastructure between Guns(rural counties), and between Eups/Myuns(rural districts) in Jeollanam-do province. For the purpose of this study, dimensions of regional disparity in basic living structure were measured by 3 components ; road, public water service and sewage disposal. By utilizing the published statistics, this study has examined 8 Guns(counties) containing Eup and Myon in Jeollanam-do province which can represent 4 different rural areal types, respectively, i,e. mountainous, semi-mountainous, flat and seashore areas. The data acquisition time of this study is fixed on end of 2009 year in order for possible collections of the most recent published statistics. It presents evidence on the magnitude and evolution of discussion of regional disparities between Guns(counties), and between Eup & Myon, and between Myons in Jeollanam-do province even though infrastructure provision level of Jeollanam-do rural areas are much more improved than the past. Concludingly, the existing disparities in this area is meaningful and so, it should be seriously reconsidered when deciding local government's budget allocation priority.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.2
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• pp.89-95
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• 2015

Pollution emission control of the 20th century, for transportation energy, are being enhanced, and then as alternative to this, because hydrogen emit only water gas emissions to be environmentally friendly energy, so hydrogen as a sustainable clean energy is in the limelight. Used in compressed natural gas engines to mix hydrogen and natural gas in both domestic and international technology development and demonstration is being carried out. The hydrogen-compressed natural gas(HCNG) charging infrastructure can be used to build a hydrogen infrastructure in the transitional aspects of a future hydrogen economy society. In this paper, for a demonstration of HCNG charging infrastructure we made and operated a $30Nm^3/h$ hydrogen generating unit and analyzed the result of the operation. We was identified the operating conditions of a reforming reactor and water gas shift reactor from an analysis result, the thermal efficiency was calculated according to the operating conditions of the total hydrogen production process.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.99-104
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• 2015

Topsoil including numerous soil seedbanks has been known to be a valuable material for ecological restoration. There is a lack of specific study for its utilization in the field of stream restoration. This study conducted a revaluation of the value of topsoil as a material for stream restoration. Furthermore, an ecological technique using topsoil was applied in an improvement project of a stream environment at the Hwanggujicheon Stream in Korea. Stockpiling and spreading topsoil was specifically applied to the revegetation of a low slope revetment and a high flow plain. The result of this application showed that topsoil played an integral role in eco-friendly restoration in terms of ecological, flood control, economic, and constructional aspects. In conclusion, this study's findings suggest that topsoil is a suitable candidate material for stream restoration.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.727-731
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• 2003

ASTER image has some advantages for classification such as 15 spectral bands and 15m ${\sim}$ 90m spatial resolution. However, in the classification using general remote sensing image, shadow areas are often classified into water area. It is very difficult to divide shadow and water. Because reflectance characteristics of water is similar to characteristics of shadow. Many land cover items are consisted in one pixel which is 15m spatial resolution. Nowadays, very high resolution satellite image (IKONOS, Quick Bird) and Digital Surface Model (DSM) by air borne laser scanner can also be used. In this study, mixed pixel analysis of ASTER image has carried out using IKONOS image and DSM. For mixed pixel analysis, high accurated geometric correction was required. Image matching method was applied for generating GCP datasets. IKONOS image was rectified by affine transform. After that, one pixel in ASTER image should be compared with corresponded 15×15 pixel in IKONOS image. Then, training dataset were generated for mixed pixel analysis using visual interpretation of IKONOS image. Finally, classification will be carried out based on Linear Mixture Model. Shadow extraction might be succeeded by the classification. The extracted shadow area was validated using shadow image which generated from 1m${\sim}$2m spatial resolution DSM. The result showed 17.2% error was occurred in mixed pixel. It might be limitation of ASTER image for shadow extraction because of 8bit quantization data.

• Ecology and Resilient Infrastructure
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• v.5 no.2
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• pp.59-71
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• 2018

Lake Enriquillo, the largest lake in the Dominican Republic, recently has undergone unusual water area changes since 2001 thus it has been affected seriously by local community's livelihood. Earthquakes and seismic activities of Hispaniola plate tectonic coupled with human activities and climate change are addressed as factors causing the increasing. Thus, a thorough study on relationship between lake area changing, and those factors is needed urgently. To do so, this study applied MESMA on MODIS data to extract water area of Lake Enriquillo during 2001 and 2012 bimonthly, with six issues 12-year. MODIS provides high temporal resolution, and its coarse spatial resolution is compensated by MESMA fraction map. The increase in water area was $142.2km^2$, and the maximum lake area was $338.0km^2$ (in 2012). Water areas extracted by two Landsat scenes at two different times with three image classification approaches (ISODATA, MNDWI, and TCW) were used to assess accuracy of MODIS and MESMA results; it indicated that MESMA water areas are same as ISODATA's, less than 0.4%, while the highest difference is between MESMA and TCW, 2.4%. A number of previously formulated hypotheses of lake area change were investigated based on the outcomes of the present study, though none of them could fully explain the changes.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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• pp.316-328
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• 2023

In this study, the characteristics of nonpoint pollutant outflow and contribution rate of pollution in Songya-stream mainstream and tributaries were analyzed. Further, water pollution management and improvement measures for pollution-oriented rivers were proposed. An on-site investigation was conducted to determine the inflow of major pollutants into the basin, and it was found that pollutants generated from agricultural land and livestock facilities flowed into the river, resulting in a high concentration of turbid water. Based on the analysis results of the pollution load data calculated through actual measurement monitoring (flow and water quality) and the occurrence and emission load data calculated using the national pollution source survey data, the S3 and S6 were selected as the concerned pollution tributaries in the Songya-stream basin. Results of cluster analysis using Pearson correlation coefficient evaluation and Density based spatial clustering of applications with noise (DBSCAN) technique showed that the S3 and S6 were most consistent with the C2 cluster (a cluster of Songya-stream mainstream owned area) corresponding to the mainstream of Songya-stream. The analysis results of the major pollutants in the concerned pollution tributaries showed that livestock and land pollutants were the major pollutants. Consequently, optimal management techniques such as fertilizer management, water gate management in paddy, vegetated filter strip and livestock manure public treatment were proposed to reduce livestock and land pollutants.

• Journal of Korea Water Resources Association
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• v.56 no.5
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• pp.347-356
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• 2023

In Water Distribution Systems (WDSs), can abnormal hydraulic and water quality conditions such as red-water phenomenon and leakage occur. To restore them, data is generated through various meters data to predict and detect. However, in the case of leakage if difficult to detect unless direct exploration is performed. Among them, unreported leakage, are not seen visually and account for the most considerable volumes of leakage, which leads to economic loss. Bur direct exploration is limited through on site conditions such as securing professional manpower. In this paper, leakage volumes and location were randomly generated for the WDS, which was assumed to be calibrated, and it was detected through a deep learning model. For abnormal data generation, the leakage was simulated using the emitter coefficient, and leakage detection was successfully performed through the generated abnormal data and normal data.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.43-50
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• 2012

The Green Infrastructure Framework refers to an interconnected network formed by greenways that links gardens, parks, green spaces, streams, wetlands, agricultural lands, and green belts. Green infrastructure supports diverse functions to environment, provides various benefits to people, and helps in the community's health and viability. It can store stormwater runoff and abate its non-point source pollutants. Due to its advantages and profits, advanced countries in environment policies have adopted green infrastructure in planning and implementing urban and regional development. The Korean government and municipalities have focused upon grey infrastructure investment in the past, which causes occurrence of natural disasters such as draught, flood, and landslides, degradation of water and air quality, decline of biodiversity, and even inhibition of economic activities. In order to alleviate these problems, it is requested to formulate and implement policies for green infrastructure at the national government level. USA and Korean situation of green infrastructure were investigated; forty components of green infrastructure were drawn. Nine policies utilized in the USA cases were identified, which are applicable to Korea. Among them, five policies can be implemented in public sector and four in private one. The green infrastructure law needed in Korea was suggested. The amendments of laws regarding green infrastructure and alternatives expending it were proposed.