• 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.

• Journal of Korean Historical Folklife
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• no.33
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• pp.115-143
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• 2010

The purpose of this study is to analyze contents and process of rites about sacrificial rites related Royal Mausoleums in early Joseon Dynasty, and to conclude, to review the position of Royal Mausoleums in the whole National Rites System. The sacrificial rites related Royal Mausoleums started from building Royal Mausoleums of 8 persons-ancestors since King T'aejo's great-great-grandparents, in 1392, founding Joseon Dynasty. In 1408, King T'aejo had died and his Kŏnwŏnnŭng (健元陵) was builted in Yangju, Gyeonggi-do. Since then, after kings of many generations died, each of Royal Mausoleums was builted solemnlly. In the process of this, sacrificial rituals modified and supplemented, especially during the reign of king Sejong(1418~1450). After all, the sacrificial rites related Royal Mausoleums was settled in KukchoOryeūi(國朝五禮儀, Five State Rites) compiled during the reign of King Sŏngjong. In process of Institutionalization of sacrificial rituals, the argument between king and vassals about four-seasons' ancestral rites was properly or not was occurred. That was because the memorial times of Royal Mausoleums overlaped Chongmyo's and more important Chongmyo's ancestral rites was neglected. But four-seasons' ancestral rites of Royal Mausoleums was continued until 17th century. Sacrificial rites related Royal Mausoleums as royal personal rites had simple processes compared to sacrificial rites of Chongmyo, upper-graded formal ancestral rites, under National Rites system. Justifying to served his parents with devotion, the kings in early Joseon Dynasty went to Royal Mausoleums 2-3 times annually. During coming and going, he show off his presence as king in power to his subjects through magnificent guard of honor. On the one hand, he met his subjects directly and acceded to various petition. Above all things, The kings in early Joseon Dynasty emphasized his military power through military training, namely, hunting, disposition of troops, and so on.

• Journal of Korea Water Resources Association
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• v.47 no.5
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• pp.459-468
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• 2014

Groyne to control the direction and velocity of flow in rivers is generally installed for the purpose of protecting riverbanks or embankments from erosion caused by running water. In particular, as interest in river restoration and natural river improvement increases, groynes are proposed as a key hydraulic structure for local flow control and riparian habitat establishment. Groynes are installed mainly in groups rather than as individual structures. In case of groynes installed as a group, flow around the groynes change according to spacing in between the groynes. Therefore, groyne spacing is regarded as the most important factor in groyne design. This study aimed at examining changes of flows around and within the area of groynes that take place according to the spacing of groynes installed in order to propose the optimal spacing for upward groynes. To examine flow characteristics around groynes, this study looked at flows in main flow area and recirculation flow area separately. In main flow area, it examined the impact of flow velocity increasing as a result of conveyance reduction that is exerted on river bed stability in relation to changes in the maximum flow velocity according to installation spacing. As a factor causing impacts on scouring and sedimentation within the area of groynes, recirculation flow in the groyne area can lead problems concerning flow within the area and stability of embankment. As for recirculation area, an analysis was conducted on the scale of rotational flow and the flow around embankment that exerts impacts on stability of the embankment. In addition, a comparative analysis was carried with reference to changes of the central point of rotational flow that occur within the area of groynes. As a result of compositely examining the results, the appropriate installation spacing is proposed as min. four times-max. six times considering a decrease in flow velocity according to the installation of upward groynes, river bed stability and stability of embankments against counterflow within the area of groynes.