• Journal of Korea Water Resources Association
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• v.30 no.1
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• pp.23-34
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• 1997

The Nanji-Do ladnfill is an ill-conditioned reclaimed land without pollution intercepting facilities, and has high ground water table and deep stratum. The purpose of this study is to analyze the solute transport in steady-state groundwater flow and to predict the solute dispersion in Nanji-Do landfill using HST-3D model. As results, the groundwater flows radially outward from the center of No. 1 and No. 2 landfills, and large amount of runoff is moved into Han River. The predicted relative concentration of total dissolved solute(TDS) at two years later was 0.25 in the weathering zone, 0.26 in the lower alluvium, and 0.28 in the upper alluvium. Thus, the further pollution to bottom rock and Han River was predicted by comparing the corresponding present values of 0.29, 0.32 and 0.35.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.68-80
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• 1987

This study was carried out to investigate the evapotranspiration and variations of soil moisture contents for soybeans. The relationship between actual evapotranspiration obtained by the water balance equation and estimated evapotranspiration obtained by the soil moisture model was analyzed. The results obtained were summarized as follows; 1. The total amount of actual evapotranspiration of soybeans during growing season was 405.7mm. The total amount of reference crop evapotranspiration of soybeans that was estimated by Pan evaporation and Hargreaves method were 547.8 mm and 586.8 mm, respectively. Crop coefficient during growing season were shown on Table 1. 2. Measured actual evapotranspiration of soybean during growing season was 405.7 mm and estimated actual evapotranspiration by pan evaporation and Hargreaves method were 424.7 mm, and 426.1mm, r3 respectively. 3. The variations of soil moisture content for soybeans were high at 10cm layer, as compared with those at 30cm and 50cm layers. Because discrepancy between the variations of soil moisture content predicted by model and observed by soil moisture meter was still great, it is required to study the consumptive types of soil moisture at each root depth.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.365-374
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• 1999

To obtain informations on vertical movements of water and solute in rice paddy field during the growing season, soil water contents and bulk electrical conductivities (${\sigma}_a$) were monitored using Time Domain Reflectometry. Soil water contents with depth showed ${\varepsilon}$-shaped profiles constituting of partly saturated zones at top and bottom layers and unsaturated zones (20-100cm) between them. Analysis by fitting with a van Genuchten-type model showed that soil water contents at 60cm were affected by both water supplied from surface water and groundwater, but at 80cm mainly affected by groundwater. Water percolation at the rate of 2cm $day^{-1}$ rates were, but large fluctuation from 10 to 38cm $day^{-1}$ in C1 layer (60-90cm). Therefore, it can be said that any water or solute entering C1 layer is very rapidly transported to C2 layer, especially during the period of high groundwater table staying, and retarded to a relatively constant percolation rate in C2 layer. This can be manifested by the fact that rapid decrease and steady increase of electrical conductivities at 50 and 110cm depth respectively, were found around that period.

• Journal of the Korean GEO-environmental Society
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• v.24 no.7
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• pp.5-14
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• 2023

Recently, earthquakes have occurred frequently in worldwide. These earthquakes cause various forms of natural and physical damage. In particular, liquefaction in which the ground shows liquid-like behavior causes great damage to the structure. Accordingly, various liquefaction damage reduction methods are being studied and developed. Therefore, in this study, a method of reducing liquefaction damage in the event of an earthquake applicable to existing structures was studied using the sheet pile method. The 1-G Shaking table test was performed and the ground was constructed with Jumunjin standard sand. A two-story model structure was produced by applying the similitude law, and the input wave applied a sine wave with an acceleration level of 0.6 g and a frequency of 10 Hz. The effect of reducing structure damage according to various embedded depth ratio was analyzed. As a result of the study, the structure settlement when the ground is reinforced by applying the sheet pile method is decreased by about 71% compared to when the ground is not reinforced, and the EDR with minimum settlement is "1". In addition, as the embedded depth ratio is increased, the calculation of the pore water pressure in the ground tends to be delayed due to the sheet pile. Based on these results, the relationship with structural settlement according to the embedded depth ratio is proposed as a relational equation with the graph. The results of this study are expected to be used as basic data in developing sheet pile methods applicable to existing structures in the future.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.3
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• pp.55-63
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• 2015

Embankment of agricultural reservoir started by four major rivers project. Most agricultural reservoirs must insure the agricultural water, they need must be ensured stability of embankment. Recently, there is a growing interest in seismic stability of structure by earthquake. Results of evaluation of the structural stability through seismic vibration test and numerical analysis, maximum displacement and the maximum acceleration is a similar trends. Appeared by increasing occurrence of the value of the displacement and acceleration of the structure with the result long period wave type in accordance with the seismic wave in the case of seismic waves, which shows the results of similar tendency as long period wave type consists of waveform seismic acceleration. Model test and numerical analysis results with in order to increase embankment agricultural reservoir, the displacement was found to ensure it is displayed within one percentage structural stability of the embankment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.1
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• pp.1-8
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• 1991

Recently, researches for buried lifelines such as pipelines have been carried out to provide for safe design. On of the major causes to the damage of buried pipelines has been soil liquefaction. Analytical models have been presented to compare with the results from recent model experiment under a soil liquefaction environment induced by seismic shaking table. The analytical results were more than two times those those of experimental measurement. Thus the objective of this study is to introduce a rigorous nonlinear analysis of equation of motion with more realistic parameters which are dynamic soil and water pressure, dynamic subgrade reaction coefficient, and damping coefficient for soil liquefaction environment.

• Coupled systems mechanics
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• v.1 no.4
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• pp.311-324
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• 2012

Previous investigations have demonstrated that strong earthquakes can cause severe damage or collapse to storage tanks. Theoretical studies by other researchers have shown that allowing the tank to uplift generally reduces the base shear and the base moment. This paper provides the necessary experimental confirmation of some of the numerical finding by other researchers. This paper reports on a series of experiments of a model tank containing water using a shake table. A comparison of the seismic behaviour of a fixed base system (tank with anchorage) and a system free to uplift (tank without anchorage) is considered. The six ground motions are scaled to the design spectrum provided by New Zealand Standard 1170.5 (2004) and a range of aspect ratios (height/radius) is considered. Measurements were made of the impulsive acceleration, the horizontal displacement of the top of the tank and uplift of the base plate. A preliminary comparison between the experimental results and the recommendations provided by the liquid storage tank design recommendations of the New Zealand Society for Earthquake Engineering is included. The measurement of anchorage forces required to avoid uplift under varying conditions will be discussed.

• 보존과학연구
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• s.6
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• pp.48-57
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• 1985

This report described the corrosion structure of excavated iron artifacts in terms of simple model based on the knowledge of the corrosion process. (Fig.1)(Table 1,2)In storing the objects, there are basically three ways in which they either break in wedges, flakes and dish-shaped flakes. Completely mineralized objects or those with only a small iron core tend to break into wedges and more solid objects either split small dish-shaped flakes or large flat ones.(Fig. 2,3,4)There are two ways, therefore, to prevent this from happening. One is to keep the artifacts rigorously dried in Silica-gel, never allowing the relative humidity to rise. This is feasible which the artifacts are in store but causes great difficulty if they are wanted for museum display. Because they still contain $ FeCl _2$ they are always at risk ; they contain the seeds of their own destruction. The other alternative is to use of washing process to dissolve out the $ FeCl _2$. In this connection, many different methods to stabilize the artifact have been employed; boiling iron in frequent changes of water, soaking in Na-sesquicarbonate solution, soaking in alkaline Na-sulphite solution. In this report, introduced the alkaline sulphite method by the N.A. North and C.Pearson.Finally, Let me extend my thanks to Ancient Monument Lab., Museum of London Conservation Lab., British Museum Conservation Div. and National Maritime Museum Conservation Lab. who have helped me and made many valuable suggestions.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1506-1512
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• 2010

In this study, model tests were performed to investigate the settlement characteristics of the rock/soil mixture subgrade with the many portion of mudstone due to the cyclic train loading in high-speed railway. Specially, from the tests varying initial degree of saturation, effects of increment of the degree of saturation in the subgrade due to rainfall or elevation of ground water table under cyclic train loading on the deformation characteristics were analyzed. From the results, in the low degree of saturation, settlement converged to some value. However, in the condition of degree of saturation larger than some value, settlement rapidly increased. Therefore, it was found that it is important to maintain the degree of saturation of subgrade below the specific level to prevent the settlement of subgrade.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.740-751
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• 2020

In the aquaculture industry, few studies are analyzing big data for intrinsic meaning. Fishcare Laboratory (www.fishcare.kr) diagnostic data from 2016-2018 was analyzed for scuticociliatosis (caused by Miamiensis avidus) outbreak patterns in cultured olive flounder Paralichthys olivaceus in Jeju, Korea. The scuticociliatosis monthly occurrence ratio is reported in the summary table after preparing and filtering the basic dataset model. Nonparametric test results suggest differences in the water temperature, body length, and weight between groups with and without scuticociliatosis. Data distribution visualization revealed that shorter body length and lighter weight increased the occurrence of scuticociliatosis. The association rule mining technique was applied to determine the primary clinical signs of mixed scuticociliatosis and bacterial infections. Venn diagrams were used to report clinical signs and suggest commonalities. These results may help diagnose and treat fish and provide a decision-making reference.