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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Civil Engineers
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Journal DOI :
Korean Society of Civil Engeneers
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Volume & Issues
Volume 29, Issue 6D - Nov 2009
Volume 29, Issue 6C - Nov 2009
Volume 29, Issue 6B - Nov 2009
Volume 29, Issue 6A - Nov 2009
Volume 29, Issue 5D - Sep 2009
Volume 29, Issue 5C - Sep 2009
Volume 29, Issue 5B - Sep 2009
Volume 29, Issue 5A - Sep 2009
Volume 29, Issue 4D - Jul 2009
Volume 29, Issue 4B - Jul 2009
Volume 29, Issue 4A - Jul 2009
Volume 29, Issue 4C - May 2009
Volume 29, Issue 3D - May 2009
Volume 29, Issue 3C - May 2009
Volume 29, Issue 3B - May 2009
Volume 29, Issue 3A - May 2009
Volume 29, Issue 2D - Mar 2009
Volume 29, Issue 2C - Mar 2009
Volume 29, Issue 2B - Mar 2009
Volume 29, Issue 2A - Mar 2009
Volume 29, Issue 1D - Jan 2009
Volume 29, Issue 1C - Jan 2009
Volume 29, Issue 1B - Jan 2009
Volume 29, Issue 1A - Jan 2009
Selecting the target year
Prediction of Scour Depth Using Incorporation of Cluster Analysis into Artificial Neural Networks
Lee, Chang-Hwan ; Ahn, Jae-Hyun ; Lee, Joo Heon ; Kim, Tea-Woong ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 111~120
A local scour around a bridge pier is known as one of important factors of bridge collapse. Two approaches are usually used in estimating a scour depth in practice. One is to use empirical formulas, and the other is to use computational methods. But the use of empirical formulas is limited to predict a scour depth under similar conditions to which the formulas were derived. Computational methods are currently too expensive to be applied to practical engineering problems. This study presented the application of artificial neural networks (ANN) to the prediction of a scour depth around a bridge pier at an equilibrium state. This study also investigated various ANN algorithms for estimating a scour depth, such as Backpropagation Network, Radial Basis Function Network, and Generalized Regression Network. Preliminary study showed that ANN models resulted in very wide range of errors in predicting a scour depth. To solve this problem this study incorporated cluster analysis into ANN. The incorporation of cluster analysis provided better estimations of scour depth up to 42% compared with other approaches.
Numerical Analysis of Dam-Break Flow in an Experimental Channel using Cut-Cell Method
Kim, Hyung-Jun ; Kim, Jung-Min ; Cho, Yong-Sik ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 121~129
In this study, dam-break flows are simulated numerically by using an efficient and accurate Cartesian cut-cell mesh system. In the system, most of the computational domain is discretized by the Cartesian mesh, while peculiar grids are done by a cutcell mesh system. The governing equations are then solved by the finite volume method. An HLLC approximate Riemann solver and TVD-WAF method are employed to calculation of advection flux of the shallow-water equations. To validate the numerical model, the model is applied to some problems such as a steady flow convergence on an ideal bed, a steady flow over an irregular bathymetry, and a rectangular tank problem. The present model is finally applied to a simulation of dam-break flow on an experimental channel. The predicted water surface elevations are compared with available laboratory measurements. A very reasonable agreement is observed.
Estimation of Design Rainfalls Considering an Increasing Trend in Rainfall Data
Kwon, Young-Moon ; Park, Jin-Won ; Kim, Tae-Woong ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 131~139
Recently frequent occurrences of heavy rainfall and increases of rainfall intensity resulted in severe flood damage in Korea. In order to mitigate the vulnerability of flood, it is necessary to estimate proper design rainfalls considering the increasing trend of extreme rainfalls for hydrologic planning and design. This study focused the estimation of design rainfalls in a design target year. Tests of trend indicated that there are 7 sites showing increasing trends among 56 sites which have hourly data more than 30 years in Korea. This study analyzed the relationship between mean of annual maximum rainfalls and parameters of the Gumbel distribution. Based on the relationship, this study estimated the probability density function and design rainfalls in a design target year, and then constructed the rainfall-frequency curve. The proposed method estimated the design rainfalls 6-20% higher than those from the stationary rainfall frequency analysis.
An Evaluation of Extreme Precipitation based on Local Downpour using Empirical Simulation Technique
Oh, Tae-Suk ; Moon, Young-Il ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 141~153
The occurrence causes of the extreme rainfall to happen in Korea can be distinguished with the typhoons and local downpours. The typhoon events attacked irregularly to induce the heavy rainfall, and the local downpour events mean a seasonal rain front and a local rainfall. Almost every year, the typhoons and local downpours that induced a heavy precipitation be generated extreme disasters like a flooding. Consequently, in this research, There were distinguished the causes of heavy rainfall events with the typhoons and the local downpours at Korea. Also, probability precipitation was computed according to the causes of the local downpour events. An evaluation of local downpours can be used for analysis of heavy rainfall event in short period like a flash flood. The methods of calculation of probability precipitation used the parametric frequency analysis and the Empirical Simulation Technique (EST). The correlation analysis was computed between annual maximum precipitation by local downpour events and sea surface temperature, moisture index for composition of input vectors. At the results of correlation analysis, there were revealed that the relations closely between annual maximum precipitation and sea surface temperature. Also, probability precipitation using EST are bigger than probability precipitation of frequency analysis on west-middle areas in Korea. Therefore, region of west-middle in Korea should prepare the extreme precipitation by local downpour events.
Derived I-D-F Curve in Seoul Using Bivariate Precipitation Frequency Analysis
Kwon, Young-Moon ; Kim, Tae-Woong ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 155~162
Univariate frequency analyses are widely used in practical hydrologic design. However, a storm event is usually characterized by amount, intensity, and duration of the storm. To fully understand these characteristics and to use them appropriately in hydrologic design, a multivariate statistical approach is necessary. This study applied a Gumbel mixed model to a bivariate storm frequency analysis using hourly rainfall data collected for 46 years at the Seoul rainfall gauge station in Korea. This study estimated bivariate return periods of a storm such as joint return periods and conditional return periods based on the estimation of joint cumulative distribution functions of storm characteristics. These information on statistical behaviors of a storm can be of great usefulness in the analysis and assessment of the risk associated with hydrologic design problems.
Detecting Nonlinearity of Hydrologic Time Series by BDS Statistic and DVS Algorithm
Choi, Kang Soo ; Kyoung, Min Soo ; Kim, Soo Jun ; Kim, Hung Soo ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 163~171
Classical linear models have been generally used to analyze and forecast hydrologic time series. However, there is growing evidence of nonlinear structure in natural phenomena and hydrologic time series associated with their patterns and fluctuations. Therefore, the classical linear techniques for time series analysis and forecasting may not be appropriate for nonlinear processes. In recent, the BDS (Brock-Dechert-Scheinkman) statistic instead of conventional techniques has been used for detecting nonlinearity of time series. The BDS statistic was derived from the statistical properties of the correlation integral which is used to analyze chaotic system and has been effectively used for distinguishing nonlinear structure in dynamic system from random structures. DVS (Deterministic Versus Stochastic) algorithm has been used for detecting chaos and stochastic systems and for forecasting of chaotic system. This study showed the DVS algorithm can be also used for detecting nonlinearity of the time series. In this study, the stochastic and hydrologic time series are analyzed to detect their nonlinearity. The linear and nonlinear stochastic time series generated from ARMA and TAR (Threshold Auto Regressive) models, a daily streamflow at St. Johns river near Cocoa, Florida, USA and Great Salt Lake Volume (GSL) data, Utah, USA are analyzed, daily inflow series of Soyang dam and the results are compared. The results showed the BDS statistic is a powerful tool for distinguishing between linearity and nonlinearity of the time series and DVS plot can be also effectively used for distinguishing the nonlinearity of the time series.
Estimation of Industrial Water Supply Benefits Using Production Function Approach
Kim, Gil Ho ; Yi, Choong Sung ; Lee, Sang Won ; Shim, Myung Pil ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 173~179
Industrial water supplied by water resource project is essential input materials along with labor, capital and land for companies. It is very important to stably secure these input materials in order for the industry to generate additional values. If the supply of industrial water is stopped, it is known damage for the industry is greater than domestic water or agriculture water based on same amount of supply. Like this, the actual value of industrial water has been highly acknowledged from the intuitive perspective, but study on the value and benefits of industrial water has been rarely conducted. Therefore, this study verified the value of industrial water supplied from water resource project, and used marginal production value as a measure to estimate the benefits of industrial water in the analysis of economic efficiency. As a result of empirical analysis using Cobb-Douglas production function and Translog production function, industries' average marginal production value was
respectively. The marginal production value for eleven industries were estimated by using same method. The marginal production value by industries presented by this study will be used as important data to calculate benefits of industrial water in the future. Moreover, the result of this study will provide reasonable criteria for decision making on the allocation of water in emergency situation, and problem of resource supply from water resource project.
Assessment of Climate Chanage Effect on Temperature and Drought in Seoul : Based on the AR4 SRES A2 Senario
Kyoung, Minsoo ; Lee, Yongwon ; Kim, Hungsoo ; Kim, Byungsik ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 181~191
This study suggests the assessment technique for climate change effect on drought in Korea based on the AR4 SRES A2 scenario reported in IPCC fourth assessment report in 2007. IPCC provides monthly outputs of 24 climate models through the DDC. One of the models is BCM2 model which was developed at BCCR in Norway and NCEP data is used for downscaling. The K-NN(K-Nearest Neighbor) and ANN(Artificial Neural Network) are selected as downscaling technique to downscale the temperature and precipitation at Seoul station in Korea. K-NN could downscale both temperature and precipitation well. ANN made a good result for temperature, but it gave a divergence result in precipitation. Finally, SPI of Seoul station is computed to evaluate the effect of climate change on drought. BCM2 predicted that temperature will increase and drought severity will increase because of the increased drought spell at Seoul station.
Evaluation of Extreme Rainfall based on Typhoon using Nonparametric Monte Carlo Simulation and Locally Weighted Polynomial Regression
Oh, Tae-Suk ; Moon, Young-Il ; Chun, Si-Young ; Kwon, Hyun-Han ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 193~205
Typhoons occurred in the tropical Pacific region, these might be affected the Korea moving toward north. The strong winds and the heavy rains by the typhoons caused a natural disaster in Korea. In the research, the heavy rainfall events based on typhoons were evaluated quantitative through various statistical techniques. First, probability precipitation and typhoon probability precipitation were compared using frequency analysis. Second, EST probability precipitation was calculated by Empirical Simulation Techniques (EST). Third, NL probability precipitation was estimated by coupled Nonparametric monte carlo simulation and Locally weighted polynomial regression. At the analysis results, the typhoons can be effected Gangneung and Mokpo stations more than other stations. Conversely, the typhoons can be effected Seoul and Inchen stations less than other stations. Also, EST and NL probability precipitation were estimated by the long-term simulation using observed data. Consequently, major hydrologic structures and regions where received the big typhoons impact should be review necessary. Also, EST and NL techniques can be used for climate change by the global warming. Because, these techniques used the relationship between the heavy rainfall events and the typhoons characteristics.
UTIS Vitalization Countermeasures Using Traffic Information Use Satisfaction Rate Model
Jang, Seok-Yong ; Jung, Hun-Young ; Ko, Sang-Seon ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 199~207
We tried to show the course of UTIS vitalization, promoting to introduce as part of the advanced traveler information system through analysis using traffic information gap model of service and structural equation modeling being used by drivers. The summary of the research is as follows. 1. We could find out the service matters needed to improve and what should be prior that make drivers' use increase through establishing the gap model of service. 2. We could establish the structural equation modeling through using traffic information use satisfaction rate, entire traffic information satisfaction rate as the observation variables. You can say it is the fruit of this research that it was confirmed the entire satisfaction rate of traffic information influenced extension, convenience, accuracy, economical efficiency in order. We could also arrange the base to determine the order of services for vitalization of UTIS in the future through grasping the priority of each service functions classified by factors. 3. It is confirmed that many drivers want multimedia function, driving support function and various functions for the personal convenience in situations except driving, which enable the drivers to enjoy leisures and interests rather than economical functions during driving due to the recent social and economic changes.
Relationship Between Mass Transfer and Degradation of Sorbed Phenanthrene in Goethite Catalyzed Fenton-like Oxidation Using Non-ionic/anionic Surfactant
Kim, Jeong-Hwan ; Choi, Won-Ho ; Kim, Jung-Hwan ; Park, Joo-Yang ;
Journal of The Korean Society of Civil Engineers, volume 29, issue 2B, 2009, Pages 207~212
Surfactants were used as representative anionic and non ionic surfactants to investigate the effect of mass transfer on the mineral-catalyzed Fenton-like oxidation of sorbed phenanthrene. Mass transfer of phenanthrene on the oxide surface or interlayer between aqueous and solid phases was generated by surfactant addition. Apparent solubility of phenanthrene was increased as surfactant concentration increasesd. In tests using Tween 80, oxidation of phenanthrene decreased as apparent solubility increased. High apparent solubility was not responsible for oxidation of sorbed phenanthrene in the sand due to the surfactant acted as a scavenger of degradation. In tests with SDS,
decomposition rate in Fenton-like oxidation was decreased by complexation between goethite and SDS. However, in tests using 32 mM of SDS, efficiency of phenanthrene treatment increased compared to the test without SDS addition. Therefore, suitable amount of SDS addition could provide optimum condition for phenanthrene oxidation on the oxide surface or interlayer between aqueous and solid phase, and decrease
decomposition, and as a result, phenanthrene removal efficiency can be improved.