• Journal of the Korean association of regional geographers
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• v.8 no.2
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• pp.229-246
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• 2002

This study is a contribution to the geographical understanding of Daejeon Area, playing the role of principal center of Choongchong Province. This area has been urbanized associated with Daejeon Basin, an important natural unit in the middle part of South Korea. In order to understand Daejeon Area in geographer's view, it is necessary to elucidate geomorphological environment of Daejeon Basin and urban expansion pattern associating with it. Our research is converged into dual objectives: one, description and interpretation of basin's landforms; other, urban expansion relating with geomorphological condition. Daejeon's urban expansion has progressed from the border zone of Daejeon Basin toward into the basin, and then vice versa. Relating to rivers valleys in the basin, the urbanization in the basin has been extended from the river valleys of lower order toward those of higher order. Understanding of the geomorphological mosaique of Daejeon basin is an important base for that of urban mosaique of Daejeon City.

• Journal of Korea Water Resources Association
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• v.36 no.1
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• pp.75-85
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• 2003

Urban rainfall-runoff procedures are more complex than the agricultural procedures due to the spreading and development of town. And the applications of theses models are more difficult due to the change of real basins. In this study, I applied SWMM and Expert System to get runoff characteristics of an urbanized basin. Noen in Daejeon is selected as a study basin. Real basin data of facilities, rainfall, runoff, and various rainfall intensity equations are used. An Expert System is used to get the parameters of this model. These results can be applied to analyze the reaction tendencies of the urban basin with the time distributions of design rainfall and the urbanization.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.467-471
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• 2006

At the current of the time, the ecologic stream is the most important concern of all the country. Daejeon metropolitan city performing the plan to secure the Daejeon cheon (stream) instream water as the 1st stage of the ecologic stream development plan for the Daejeon 3 main stream. During the performing the plan to secure the Daejeon cheon (stream) instream water, the water sources are decided to supply from Yudeng cheon and Daecheong Dam by the various water sources evaluation. For the investigation of flow and quality of instream water, I applicate the HEC-RAS and QUAL2EU. Instream water is proposed as the $10{\sim}30cm$ water depth and 2 degree water quality (lower the BOD 2.0 ppm) by the report of city. It is reasonable to the water depth objective, but the water quality objective is not reasonable because of the seasonal quality changes of supplied water. I suggest that the basin management plan include the non-point source elimination must comprised to the Daejeon ecologic stream project.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.223-229
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• 2010

This study is to analyze location conditions for erosion control dams to be constructed in Chungcheongnam-do, Daejeon Metropolitan City, Chungcheongbuk-do and Gyeongsangbuk-do in order to establish proper conditions for erosion control dams in the future. 199 sites where erosion control dams are expected to be built in 2010 were chosen and investigated in terms of 12 factors including basin area, basin slope, and landslide risk. The results showed that erosion control dams for Chungcheongnam-do and Daejeon Metropolitan City are mostly impermeable gravity dams mainly composed of concrete. In contrast, Chungcheongbuk-do and Gyeongsangbuk-do are increasing the number of permeable or compound erosion control dams. Basin analysis at planned erosion control dam sites showed that at least 44.5% of the total area has high landslide risk. Gyeongsangbuk-do had the largest basin area for erosion control dam sites at 157.3ha, followed by Chungcheongbuk-do at 64.4ha and Chungcheongnam-do at 54.8ha. Analysis of sand deposits in the Chungcheongnam-do erosion control dam built in 2010 confirmed an average deposit of 971.8m3. The sand deposit capacity and amount of sediment control for erosion control dams have a very low correlation with basin area or flow path slope, and this needs to be addressed in future sand deposit capacity designs.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.109-114
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• 2012

In this study, both sedimentation and thickening experiments were conducted for residuals produced from an advanced water treatment plant for more accurate and practical design of residual treatment train. In order to design a backwashed residual sedimentation basin (SRSB) in the filter backwash water recycle system, two kinds of backwash waters, one from sand filter (SFBW) and the other from GAC adsorption bed (GACBW), were separately collected and their surface loading rate measured. In addition, in order to design a gravity thickener, batch thickening tests were conducted for concentrated residuals taken from sedimentation basin and their limiting solid flux ($SF_{L}$) measured. From the experimental results and consideration of the seasonal characteristics of the residual, surface loading rate of $70m^{3}/m^{2}{\cdot}d$ was proposed as a design parameter for SRSB and solid loading rate of 20 kg $TS/m^{2}{\cdot}d$ was proposed as a design parameter for gravity thickeners. Finally, the material mass-balance was made for the design of each unit process in the residual treatment train.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.105-112
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• 2010

The objective of this study is to develop a standardized model for analyzing water balances in large scaled water basin by considering agricultural water districts, and to evaluate the hydrological feasibility of applying this model to several water districts such as Nonbul, Geumbok, Daejeon 1, Daejeon 2, and Cheonggang in Geum river basin. Ten types of stream network were considered in developed model. Using this model, streamflows were simulated by major stations and water balances were analyzed by water districts. Simulated streamflows and measured streamflows were compared at check stations such as Gapcheon and Bugang stations in which Nash and Schcliffe's model efficiencies were 0.633, 0.902, respectively. This results showed its applicabilities to national water resources plan, rural water development plan, and total maximum daily load plan in Korea.

• The Journal of Information Technology
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• v.10 no.2
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• pp.1-9
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• 2007

This study analyzed major cities of Chung-cheong area in Korea, -Daejeon($36^{\circ}11'{\sim}36^{\circ}30'\;N$, $127^{\circ}15'{\sim}127{\circ}34'\;E$), Chungju($36^{\circ}54'{\sim}37{\circ}02'\;N$, $127^{\circ}52'{\sim}128^{\circ}02'\;E$), and Cheongju($36^{\circ}34'{\sim}36^{\circ}44'\;N$, $127^{\circ}22'{\sim}127^{\circ}34'\;E$)- their characteristics as a Information Site. The geology map, a summit level map, and a drainage network map are created and analyzed the Site. The results are as follows : First, the geology of these cities are related with the shapes and the characteristics of the inner basins. The relief of inner basin determines by the characteristics of the bedrocks. Second, the major cities are close to rivers and the size of the granite & alluvium area influences the relief energy of the urban areas. Finally, the drainage networks explains the process involved in forming the basin and development of urban area.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.265-279
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• 1975

This study was conducted to investigate the development of Gab river-basin which was a part of the farm land enlargement to contribute to the increased production of food. The results were as follows; 1. Gab river has the upper stream which occupy 50 percent in moumtains and the mid-stream in the Daejeon city area, and the downstream in a field which is about 22.9 percent in which farming area per household is 0.82 ha., agricultural population is 76 percent except of Daejeon city. Also, urban enlargement of mid-stream basin and development of industrial area in the lower stream diminish farm land. Consequently, this area should be developed to farm land to increase farming size. 2. There is no possibility to develop farm land in mountains of which (64.9 percent) is forests and in midstream which was constructed river-improvement. But Weonjeong area and Yongcheon area will be effective area. 3. If river banks of Weonjeong area will make straight with cost of construction 195,000,000 won, bank length 6 km will be useless, water will flow smoothly, flood will be prevented, farm land will develop 21.66 ha in which rice will produce annually 81.698 M/T which is about 10,860,000 won. 4. This area has good conditions of development. that is, investment efficiency (B/C) is 1.47 more than 1.00. 5. This area is a multiple purpose development district. The reasons are that there are beautiful mountains and a reservoir to be expected to construct, so it will be a sight seeing district in the vicinity of Daejeon city. 6. If Honam railway double line and river straight construction had executed simultaneously, cost of construction 50,000,000 won would have saved.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.605-609
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• 2005

This study is to perform the rainfall-runoff analysis of the basin of Yongdam dam where is loacted in the Geumriver basin. The model used is the SAC-SMA model which was developed by U.S. National Weather Service. The Precipitation data used as the input data of the model are daily ones observed in 2002 and the mean of values recorded in 5 rainfall stations. The evaporation data are used observed in Daejeon meteorological station. The geographical data such as basin slope and stream gradient are elicited from the numerical map analysis. In the verification through the comparison of calculated daily inflow with observed one, parameters used in the model are estimated manually. As the result of verification, total annual calculated inflow is 13,547CMS and agree accurately with the observed one. During the period of one year of 2002, before 100 days and after 250 days, the soil moisture condition in the upper zone was significantly dry and in spite of the rainfall in this period, the runoff was not generated. Through this result, we can observe that the moisture condition in the soil affects strongly the runoff in a basin.

• Journal of Ocean Engineering and Technology
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• v.31 no.4
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• pp.257-265
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• 2017

In this study, a series of numerical simulations was conducted in order to design a truncated mooring line with a static similarity to the prototype. A finite element method based on minimizing the potential energy was utilized to describe the dynamics of mooring lines. The prototype mooring lines considered were installed at a water depth of 1,000 m, whereas the KRISO ocean engineering basin (OEB) in Daejeon has a water depth of 3.2 m, which represents 192 m using a scaling of 1:60. First, an investigation for the design of the truncated mooring line was carried out to match the static characteristics of the KRISO Daejeon OEB environment. Then, the same procedure was performed with the KRISO new deepwater ocean engineering basin (DOEB) that is under construction in Busan. This new facility has a water depth of 15 m, which reflects a real scale depth of 900 m considering the 1:60 scaling factor. A finite element method was used to model the mooring line dynamics. It was found that the targeted truncated mooring line could not be designed under the circumstances of the KRISO OEB with any material properties, whereas several mooring lines were easily matched to the prototype under the circumstances of the KRISO DOEB.