• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.1
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• pp.9-15
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• 2013

This study is to evaluate the parameter behavior of VfloTM distributed rainfall-runoff model by applying 3 kinds of rainfall interpolation methods viz. Inverse Distance Weighting (IDW), Kriging (KRI), and Thiessen network (THI). For the 1,544 $km^2$ Dongcheon watershed of Nakdong river, the model was calibrated using 4 storm events in 2007 and 2009, and validated using 2 storm events in 2010. The model was calibrated with Nash-Sutcliffe model efficiency of 0.97 for IDW, 0.94 for KRI, and 0.95 for THI respectively. For the sensitive parameters, the saturated hydraulic conductivity ($K_{sat}$) for IDW, KRI, and THI were 0.33, 0.31, and 0.43 cm/hr, and the soil suction head at the wetting front (${\Psi}_f$) were 4.10, 3.96, and 5.19 cm $H_2O$ respectively. These parameters affected the infiltration process by the spatial distribution of antecedent moisture condition before a storm.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.90-101
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• 2004

The present trend of disposing treated sewage water by allowing it to infiltrate the soil brings a new dimension to environmental problems. It is therefore necessary to identify the chemicals likely to be present in treated sewage water. A soil column experiment was conducted to determine the behavior of chemical species in soil columns applied with secondary treated sewage water. To predict the behavior of chemical species, a multicomponent solute transport model that includes the biochemical redox process and cation exchange process was developed. The model computes changes in concentration over time caused by the processes of advection, dispersion, biochemical reactions and cation exchange reactions. The solute transport model was able to predict the behavior of the different chemical species. The model reproduced the sequential reduction reaction. To design the safe depth of plow layer where $NO_3^-$ is totally reduced, a numerical study of $NO_3^-$ leach was done and it was found out that the pore velocity and concentration of $CH_2O$ at the inject water was found to affect $NO_3^-$ reduction in the mobile pore water phase. It is revealed that the multicomponent solute transport model is useful to design the land treatment system for $NO_3^-$ removal from wastewater.

• Nuclear Engineering and Technology
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• v.37 no.4
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• pp.385-390
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• 2005

The effect of the Wolsong Tritium Removal Facility on the change of tritium concentration in the soil water was assessed by introducing a dynamic compartment model. For the mathematical modeling, the tritium in the environment was thought to come from two different sources. Three global tritium cycling models were compared with the natural background concentration. The dynamic compartment model was used to model the behavior of the tritium from the nuclear power plants at the Wolsong site. The source term for the dynamic compartment model was calculated with the dry and wet deposition rates. The area around the Wolsong nuclear power plants was represented by the compartments. The mechanisms considered in deriving the transfer coefficients between the compartments were evaporation, runoff, infiltration, hydrodynamic dispersion, and groundwater flow. We predicted what the change of the tritium concentration around the Wolsong nuclear power plants would be after future operation of the tritium removal facility to show the applicability of the model. The results showed that the operation of the tritium removal facility would reduce the tritium concentration in topsoil water quickly.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.33-44
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• 2000

Background: To evaluate airway responses and inflammation to antigen in Sprague-Dawley rat asthma model, we examined airway responses, serial histologic changes of the lung, and the relationship between airway responses and airway inflammation after antigen airway challenge. Methods: Sprague-Dawley rats were sensitized with subcutaneous injection of 10 ${\mu}g$ ovalbumin(OA). Antigen airway challenges were done 14~16 days after sensitization and the sensitized rats were sacrificed 1h($A_E$), 6~8h($A_L$) and 1day($A_D$) after airway challenge, to examine the histologic changes of the lung. Airway responses were measured by body plethysmograph and recorded by enhanced pause(Penh) as an index of airway obstruction 6~8h after antigen challenges. Nonsensitized controls(10 rats) were also challenged with antigen and sacrificed 1 day later. Histopathologic examination of two trachea, large bronchi, small bronchi, and vessels was performed to evaluate the severity of inflammation and eosinophilic infiltration with H&E stain. Results: In 17 of 20 rats(85%) in both groups, we observed airway responses. Among them, an early response(ER) in 15 rats(75%), an dual response in 5(25%), and an late response(LR) only in 2 rats(10%) displayed. There were no significant differences in the severity of inflammation among the trachea, large bronchi, small bronchi and vessels in all groups after antigen challenge(p>0.05) and between early and late responders. The significant eosinophil infiltration was observed in 5 rats(50%) of AL(p<0.05) compared with in AE and controls. Also, eosinophil infiltration was observed in higher trend in LR(57.1%) compared to ER(40%)(p>0.05). Conclusion: Sprague-Dawley rats sensitized with subcutaneous injection of OA showed a significant airway responses to antigen challenge. But antigen challenges caused a little eosinophil infiltration and no significant airway inflammation. Asthma model of Sprague-Dawley rats could be useful for antigen-induced airway responses, but this model has a limitation for the study of human asthma because of no significant pathologic change.

• The Journal of Internal Korean Medicine
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• v.30 no.4
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• pp.788-798
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• 2009

Objective : This study was undertaken to investigate effects of Opuntia ficus-indica (OP)extract on an asthma murine model. Methods : The total number of cells and eosinophils in BALF and the infiltration of inflammatory cells into lung tissues were determined by hematoxylin and eosin staining. Results : The number of OVA-induced total cells and eosinophils, a phenomenon of asthma, were decreased by treatment of the animals with OP extract (200 mg/kg) (respectively, p < 0.001 and p<0.01). Furthermore, we showed that OP extract reduced the increased immune cell infiltration induced by ovalbumin (p < 0.01). The levels of interleukin (IL)-4 in BAL fluid were measured by enzyme-linked immunosorbent assay, because the eosinophilia is associated with a T helper (Th) 2 response including IL-4. The level of OVA-induced IL-4 was decreased by OP extract in BAL fluid (p < 0.05). We investigated whether OP extract reduced nitrite (NO) production on lipopolysaccharide (LPS)-stimulated RAW 264.7 sells, because asthma is an inflammatory disease. The level of LPS-induced NO production was decreased by OP extract (50, 100 and 200 mg/ml) on RAW 264.7 cells (respectively, p < 0.05, p<0.01 and p<0.05). Conclusions : Our results indicate that OP extract has an inhibitory effect on lung eosinophilia of asthma and suggest that OP extract is a therapeutic candidate in the treatment of inflammatory disease, including asthma.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.6
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• pp.467-474
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• 2015

Allergic rhinitis is a growing tendency to increase. Following this tendency, allergic rhinitis is lively studied also in Korean oriental medicine. Bupleuri Radix (BR) has been used for many inflammatory diseases, but experimental backgrounds are not enough to treat allergic rhinitis. So in this study, effects of BR on OVA-induced allergic rhinitis model of BALB/c mice were examined. Thirty two BALB/c mice are equally devided into four groups; control group, OVA group, OVA+BR group, OVA+Cet group. The OVA, OVA+BR and OVA+Cet groups were induced allergic rhinitis by sensitizing to OVA. And then saline solution included BR (10.6 mg/kg body weight) was administered to the OVA+BR group orally. The number of nasal rubbing and nasal sneezing was evaluated for 10 days and later serological and histological changes were analyzed. Serological analysis included the serum levels of cytokines and chemokines (IL-4, IL-5, IL-12, MCP-1, MIP-2), total IgE and OVA-specific IgE levels in serum. Histological analysis included thickness of nasal septum, eosinophil counts changes of nasal mucosa, infiltration of eosinophil in nasal mucosa and histological changes of nasal mucosa. The number of nasal rubbing and nasal sneezing was significantly decreased in the OVA+BR group. The serum levels of IL-4, IL-5, MCP-1, MIP-2 were significantly decreased in the OVA+BR group but the serum levels of IL-1β had not significance. Total IgE and OVA-specific IgE levels in serum were decreased in the OVA+BR group, but total IgE levels in serum had only significance. Thickness of nasal septum, eosinophil counts of nasal mucosa and infiltration of eosinophil in nasal mucosa were significantly decreased in the OVA+BR group. From the results of this study, we think that BR has an effect on improvement of allergic rhinitis by improving nasal rubbing and nasal sneezing, reducing histological changes of nasal mucosa and infiltration of eosinophil in nasal mucosa, inhibiting increasing of the serum levels of cytokines, chemokines and total IgE.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.26-41
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• 2016

Catchment Hydrologic Cycle Assess Tool (CAT) is a model for hydrologic cycle assessment based on physical parameters. In this study, CAT was applied for short-term runoff simulation and connected with model-independent parameter estimation (PEST) for auto-calibrating parameters. The model performance was compared with HEC-HMS, which is widely used for short-term runoff simulation. The study area is the Pangyo Watershed ($22.9km^2$), which includes the Unjung-Cheon and Geumto-Cheon tributaries of the Tan-Cheon stream. Simulation periods were selected from six rainfall events of a two-year period (2006-2007). For the runoff simulation, CAT was applied using three types of infiltration methods (excess rainfall, Green and Ampt and Horton). Sensitivity analysis was carried out to select the parameters and then CAT was optimized using PEST. The model performance of HEC-HMS and CAT-PEST for the rainfall events were within an acceptable limit with Nash Sutcliffe efficiencies (NSE) of 0.63-0.91 and 0.42-0.93, respectively. The simulation results of HEC-HMS have high accuracy in the case of rainfall events that have a sensitive relationship between initial soil moisture conditions and runoff characteristics. The results of CAT-PEST indicated the possibility of reflecting a real runoff system using various physical parameters.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.4
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• pp.57-64
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• 1985

An optimization model is presented that can be used in the determination of a loss rate function and conceptual runoff models using observed rainfall and runoff data. In order to estimate the lumped parameters and to control inputs of the model, the differential equations, linear for underground flow and non-linear for overland flow, are transformed into state equations. Parameters of a loss rate function and runoff model under stationary assumption can be determined by the following procedures: optimization technique, linear control and non-linear curve fitting theory using several multiperiod storms simultaneously or using individual multiperiod storms. An infiltration equation that includes rainful intensity is used to dtermine the effective rainfall for a given rain of varying. The optimization model is applied to storms in Hyong Song watershed of Wonju area. The results of the new model are compared with earlier one.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.38-45
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• 2007

A one-dimensional kinematic wave model was used to calculate temporal and spatial changes of the highway runoff. Infiltration into pavement was considered using Darcy's law, as a function of flow depth and pavement hydraulic conductivity ($K_p$). The model equation was calculated using the method of characteristics (MOC), which provided stable solutions for the model equation. 22 storm events monitored in a highway runoff monitoring site in west Los Angeles in the U.S. were used for the model calculation and evaluation. Using three different values of $K_p$ ($5{\times}10^{-6}$, $10^{-5}$, and $2{\times}10^{-5}cm/sec$), total runoff volume and peak flow rate were calculated and then compared with the measured data for each storm event. According to the calculation results, $10^{-5}cm/sec$ was considered a site representative value of $K_p$. The study suggested a one-dimensional method to predict hydrodynamic behavior of highway runoff, which is required for the water quality prediction.

• Proceedings of the Korea Water Resources Association Conference
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• 1990.07a
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• pp.19-19
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• 1990

The paper presents the development and applications of physically-based urban runoff analysis model, URAM, which is capable of simulating sewer runoff hydrographs and inundation conditions within a small urban catchment. The model considers three typical flow conditions of urban drainage networks, whichn are overland flow, gutter flow, and conduit flow during a storm. Infiltration, retention storage and flow routing procedures are physically depicted in model. It was tested satisfactorily with field data from a tested catchment having drainage area of 4.91 ha. It was also applied to other urban areas and found to adequately simulate inundation areas and duration as observed during storms. The test results as well as model components are described in the paper.