• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.432-435
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• 2006

To evaluate geology and extent of leachate migration around the landfills, electrical resistivity survey were conducted in area of uncontrolled landfills in Cheonan and Wonju. The Cheonan landfill is located above the paddy fields and the resistivity survey lines were crossed to confirm possible pollution of the paddy fields by leakage of the landfill leachate. In Wonju, the landfill and the downgradient paddy fields are divided by a concrete barrier wall. At the bottom of the landfill, there is a leachate settlement system but has not been in operation. And a total of 4 survey line installed (1 parallel and 3 perpendicular to mean groundwater flow direction). According to the resistivity survey results, the landfill leachate in Cheonan appeared to be restricted only within the interior of the landfill, not to migrate into the subsurface of the paddy fields. These results are well consistent with electrical conductivity values of groundwaters obtained from a periodic analysis of water qualities. In Wonju, however, it was inferred that the leachate emanating from the landfill migrated beneath the abandoned leachate settlement system and it would reach the downgradient paddy field.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.934-944
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• 2007

Fine suspended solids (SS) induced into a reservoir after flood events play important ecological and water quality roles by presenting persistent turbidity and attenuating light. Thus the origin and physical features must be characterized to understand their transport processes and associated impacts, and for the establishment of watershed based prevention strategies. This study was aimed to characterize the physical properties of the SS sampled from Daecheong Reservoir and its upstream rivers during flood events. Extensive field and laboratory experiments were carried out to identify the turbidity-SS relationships, particle size distributions, settling velocity, and mineral compositions of the SS. Results showed that the turbidity-SS relationships are site-specific depending on the locations and flood events in the system. The turbidity measured within the reservoir was much greater than that measured in the upstream rivers for the same SS value. The effective diameters ($D_{50}$) in the rivers were in the range of $13.3{\sim}54.3{\mu}m$, while those in the reservoir were reduced to $2.5{\sim}14.0{\mu}m$ due to a fast settling of large particles in the rivers. The major minerals consisting of the SS were found to be Illite, Muscovite, Albite, and Quartz both in the rivers and reservoir. Their apparent settling velocities at various locations in the reservoir were in the range of 0.06~0.13 m/day. The research outcome provides a fundamental information for the fine suspended particles that cause persistent turbidity in the reservoir, and can be used as basic parameters for modeling study to search watershed based optimal control measures.

• Tunnel and Underground Space
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• v.30 no.4
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• pp.335-358
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• 2020

We present a numerical model to simulate coupled hydro-mechanical behavior of fault using TOUGH-FLAC simulator. This study aims to develop a numerical method to estimate fluid injection-induced fault reactivation in low permeability rock and to access the relevant hydro-mechanical stability in rock as part of DECOVALEX-2019 Task B. A coupled fluid flow and mechanical interface model to explicitly represent a fault was suggested and validated from the applications to benchmark simulations and the field experiment at Mont Terri underground laboratory in Switzerland. The pressure build-up, hydraulic aperture evolution, displacement, and stress responses matched those obtained at the site, which indicates the capability of the model to appropriately capture the hydro-mechanical processes in rock fault.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.341-350
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• 2000

The objectives of this study are to develop a state-space form of stochastic dynamic storage function routing model and to test the model performance for real-time flow forecast. The selected study area is the main Han River starting from Paldang Dam site to Indogyo station and the 13 flood events occurred from 1987 to 1998 are selected for computing model parameters and testing the model performance. It was shown that the optimal model parameters are quite different depending on Hood events, but the values used on field work also give reasonable results in this study area. It is also obvious that the model performance from the stochastic-dynamic model developed in this study gives more accurate and reliable results than that from the existing deterministic model. Analysis for allowable forecast lead time leads that under the current time step the reasonable predicted downstream flows in 5 hours time advance are obtained from the stochastic dynamic model on relatively less lateral inflow event in the study area.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.257-263
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• 2008

We analyzed the statistical properties for the conductive background fractures in the Low and Intermediate Level Waste(LILW) disposal site to conceptualize of its groundwater flow system. The background fractures were classified to fracture sets based on their trends and plunges that were obtained from the borehole logging data, and then the fracture transmissivity distribution was inferred from the fixed interval hydraulic test results. The fracture size distribution of each fracture set was estimated using the fracture density and fracture mapping data. To verify the analyzed results, we compared observed field data to simulated one from the DFN model that was constructed with the analyzed statistical properties of the background fractures, and they showed a good agreement.

• The Journal of Engineering Geology
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• v.18 no.3
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• pp.303-309
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• 2008

A probability of slope hazards was predicted at a natural terrain around the stone relics of Jinjeon-saji area, which is located in Yangyang, Kangwon Province. As the analyzing results of field investigation, laboratory test and geology and geomorphology data, the effect factors of landslides occurrence were evaluated. Also, the landslides prediction map was made up using the prediction model by the effect factors. The landslide susceptibility of stone relics was investigated as the grading classification of occurrence probability. In the landslides prediction map, the high probability area was $3,489m^2$ and it was 10.1% of total prediction area. The high probability area has over 70% of occurrence probability. If landslides are occurred at the predicted area, the three stories stone pagoda of Jinjeon-saji(National treasure No. 122) and the stone lantern of Jinjeon-saji(Treasure No.439) will be collapsed by debris flow.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.171-179
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• 2004

Today, the number of vehicle increased rapidly with the development of modem science technology, and it caused serious problems; traffic jam, accident and pollution etc. One of the solve methods these problems it is necessary to develope the vehicle navigation systems and it is already widely used to in field of military etc. Vehicle navigation system can increase the efficiency of traffic flow and offer at a drivers at a best driving conditions. In the vehicle navigation, most important thing is to measure of correct position. There are classifiable as three types. The first is G.P.S., method at artificial satellites which measures the present position and velocity any time, any where in the world at the same time. Secondly, a vehicle can determine its position and path information with a gyroscope and odometer signal, which is called Dead-Reckoning method. Thirdly, hybrid navigation system is the combined of two methods to make utilize the advantage of each navigation system. In the paper, we are analyzed to characteristics at a gyro sensor and introduce at a composition of hybrid navigation system which is combined with the G.P.S., D.R., and map-matching technique. We analyze deeply for the Map-Matching method and explain the coordinate transformation for G.P.S., and the Hybrid navigation algorithm is developed and experimented. Finally, we conclude and comment about our road test results.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.43-53
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• 2016

The purpose of this study is to examine the meaningfulness and the possibility of developing kinetic narrative educational contents based on English literature with convergent approaches. To accomplish the objective, this paper examines three areas of research such as kinetic education, English literature education, and total physical response-storytelling method. It introduces the following three stages of development procedure: 1) selecting and analyzing English literature, 2) designing a prototype including the story flow, the movement and the motion interaction design, and 3) constructing motion database using Laban movement analysis. Then, how to apply it to young learners is illustrated with 'the story of the three little pigs,' Finally, implication for the field of young learner English education and English literature is discussed.

• Particle and aerosol research
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• v.12 no.4
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• pp.145-150
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• 2016

During the chemical mechanical planarization (CMP) process, slurry that comprises abrasive particles can directly affect the CMP performance and quality. Mainly, the large particles in the slurry can generate the defects on the wafer. Thus, many kinds of filters have been used in the CMP process to remove unwanted over-sized particles. Among these filters, the point-of-use (POU) filter is used just before the slurry is supplied onto the CMP pad. In the CMP research field, analysis of the POU filter has been relatively exceptional, and previous studies have not focused on the standardized filtration efficiency (FE) or filter performance. Furthermore, conventional evaluation methods of filter performance are not appropriate for POU filters, as the POU filter is not a membrane type, but is instead a depth type roll filter. In order to accurately evaluate the POU filter, slurry FE according to particle size was measured in this study. Additionally, a CMP experiment was conducted with filtered slurry to demonstrate the effects of filtered slurry on CMP performance. Depending on the flow rate and the filter retention size, the FE according to particle size was different. When the small and large particles have different FEs, the total filtration efficiency (TFE) can still have a similar value. For this reason, there is a need to measure the FE with respect to the particle size to verify the effects of the POU filter on the CMP process.

• Solar Energy
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• v.12 no.3
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• pp.47-59
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• 1992

In the concentric tube type recuperator, which is the most typical type of radiation recuperator, installed on the exhaust-secion of industrial furnace, air flows between the adiabatic outer tube and the inner tube in which exhausted gas flows with high temperature. The waste heat of the exhausted gas is transferred to the inner tube, and transferred from the inner tube to the flowing air. The heat transfer by radiation In the concentric tube type recuperator is modeled using spherical harmonics approximation, namely, P-N method and numerically analyzed considering the effect of dynamic flow field. The results are compared with the existing empirical data. In addition, a theoretical method is presented for the analysis of the heat transfer characteristics of a recuperator with a reradiator installed in the inner tube, which causes re-radiant in the inner tube, and the characteristics of the recuperator is analyszed and defined.