• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.60-66
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• 2009

This study presents an experimental investigation of the shallow water impact of a box type structure. The analysis was done based on the video images captured by a high speed camera, the flow field obtained by PIV (Particle Image Velocimetry), and pressure measurements in the divided region. The video images showed quite good agreement with the description given by Korobkin. The PIV measurements of the velocity field provided a clear view of the flow pattern for all three stages. The pressure was measured at the bottom of the tank with strain gauge type pressure gauges. The pressure measurements showed the characteristics of divided regions.

• KCID journal
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• v.14 no.2
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• pp.181-193
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• 2007

The characteristics of non-point source pollutant loads in middle-stream of Nakdong River Were studied through analysis of pollutant loads of 8 sub-watersheds divided based on administrative district. The pollutant concentration of each sub-watershed was collected from Nakdong-River Water Research Institute and Daegu Regional Environmental Office, respectively. Pollution items analysed in this study were BOD, SS, T-N and T-P. High degree of non-point pollution was observed from Gumi, Goryeong, Gyeongsan, Daegu and Sungju, and pollution was usually increased during rainy season. This result indicates that a given pollution condition within the watershed can be more sensitive than location factor to the level of water quality. The main sources of non-point pollution were population and livestock, as well as landuse factor, and were found to significantly contribute to the water pollution. Alternative solutions for controlling pollution sources, therefore, should be provided to meet target levels of water quality in this region.

• Journal of Korea Water Resources Association
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• v.46 no.3
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• pp.245-252
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• 2013

The reflection coefficients of monochromatic water waves over various shear currents flowing on a constant topography are estimated analytically in this study. The region of varying shear currents is represented by a finite number of tiny steps with a uniform depth topography. The proper numbers of steps and evanescent modes needed for the analysis are proposed by a series of convergence tests. The characteristics of reflection coefficients for various shear currents conditions are also examined.

• Proceedings of the Korea Water Resources Association Conference
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• 1996.05a
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• pp.689-694
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• 1996

The purpose of this study is to find sedimentation patterns variation in Seamangum coastal sea region. Water circulations are calculated diagnostically from the observed water temperature and salinity data and wind data and tidal residual current. There dimensional movements of injected particles due to currents, tubulence and sinking velocity are tracked by the Euler-lagrange method. Calculated sedimentation patters of riverine material are highly similat to the observed ones.

• Environmental and Resource Economics Review
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• v.16 no.3
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• pp.629-641
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• 2007

Chinese government has implemented the West Development Strategy since 1999 to boost the region's growth and prevent the environmental degradation. Until now, the regional economy and living standard in Western China have been greatly improved, while it also indicated by the State Council that the ecological environment still deteriorated with part improvement, and pressure of water shortage increased. The paper focus on the relationship of GDP per capita and the volume of industrial waste water discharge of all the 12 provinces in Western China from 1989 to 2004, by the expanded EKC model in the cubic form. Results show that they mainly have down trend in the whole sample space but small up trend in the recent years. That means controlling of industrial wastewater discharge is still an important task to be insisted in the Western China.

• Current Optics and Photonics
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• v.1 no.4
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• pp.278-283
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• 2017

We theoretically study the dynamics of water tetramer in intense femtosecond laser pulses with different frequencies. The simulations are carried out by incorporating the molecular dynamics method non-adiabatically into the time-dependent local-density approximation (TDLDA-MD). Three typical scenarios of water tetramer including the normal vibration with enlarged OH bonds, free OH bonds breaking and the pure Coulomb explosion are presented by investigating the electronic and ionic dynamics. The result indicates that the ionization is enhanced and the corresponding fragmentation effect as well as the damping of the dipole moment are found more notably when increasing the laser frequency especially when the frequency falls in the resonant region of the absorption spectra. The study of the level depletion reveals that the ratio of the emission amount from different levels can be controlled by changing the laser frequency referring to the Keldysh parameter.

• Journal of the Korean Chemical Society
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• v.17 no.4
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• pp.235-239
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• 1973

Kinetic studies of benzoyl chlorides solvolysis have been carried out in acetone-water mixtures. Results show that bimolecular process predominates in the low water content region but SN1 process becomes increasingly important in the high water content solvent composition.

• Korean Journal of Remote Sensing
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• v.16 no.4
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• pp.315-325
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• 2000

Observations were made to validate ocean color algorithms in the Ulleung Basin, East Sea in May 2000. Small scale and meso-scale surveys were conducted for the validation of ocean color products (nLw: normalized water-leaving radiance and chlorophyll concentration). There were discrepancies between SeaWiFS and in situ nLw showing the current aerosol models of standard SeaWiFS processing software are less than adequate (Gordon and Wang, 1994). Applying the standard SeaWiFS in-water algorithm resulted in an overestimation of chlorophyll concentration. This is because that CDOM absorption was higher than the estimated chlorophyll absorption. TSS concentration was also high. Therefore, the study region deviated from Case 1 waters. The source of these materials seems to be the entrainment of coastal water by the Tsushima Warm Current. Study of the bio-optical properties in other season is desirable.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.195-195
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• 2017

The patterns of occurrence of typhoons in North Pacific region are constantly changing with the increase of temperature in sea surface and the occurrence of El Nino and La Nina and changes of their development caused by global warming. In addition, alterations of flow regimes caused by large-scale hydraulic construction projects in the past few years and changes in precipitation patterns caused by climate change have imposed increased stress on hydroecology while the indiscreet utilization of water resources has a negative environmental impact on the water flows in the natural rivers and streams and hydroecological structures. The purpose of this study is to explore the impact of altered hydrologic regime on stream and riparian ecosystems that are most vulnerable to climate variability and extremes such as typhoons.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.6
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• pp.1007-1019
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• 2015

The determination of the required seawall height is usually based on the combination of wind speed (or wave height) and still water level according to a specified return period, e.g., 50-year return period wind speed and 50-year return period still water level. In reality, the two variables are be partially correlated. This may be lead to over-design (costs) of seawall structures. The above-mentioned return period for the design of a seawall depends on economy, society and natural environment in the region. This means a specified risk level of overtopping or damage of a seawall structure is usually allowed. The aim of this paper is to present a conditional risk probability-based seawall height design method which incorporates the correlation of the two variables. For purposes of demonstration, the wind speeds and water levels collected from Jiangsu of China are analyzed. The results show this method can improve seawall height design accuracy.