• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.1
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• pp.97-107
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• 1989

An inverse self-iterative procedure is developed to estimate layer moduli of 3 layered flexible pavement structures from FWD deflection basins. The theoretical deflection basins of pavement structures obtained by full factorial design are used for the parametric study on the characteristics of deflection basins and the regression analysis. The factorial design is performed for asphalt pavement structures with stabilized base layer and granular base layer, respectively. The initially assumed layer moduli by regression equations and relations between the rate of change of moduli and deflections are used in the procedure to ensure efficiency and accuracy of self-iterative model. The SINELA computer program is used for inverse self-iterative applications to determine theoretical responses. The computer program of this procedure is coded for personal computers and is verified through numerical model tests.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.712-714
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• 2017

미병의 예방과 관리의 중요성이 거론되고 있으나, 미병에 대한 분류나 진단을 위한 확고한 근거가 미약한 상황으로서 미병 진단 인자 분류를 위한 생리시스템 모델 개발이 필요한 시점이다. 본 연구의 목적은 개발한 생리학적 모델이 미병 단계를 구별하는데 효과 및 유용성이 있는지를 임상 검증하기 위하여 생리학적 모델 인공지능 시뮬레이션을 개발하고자 함이다. 인공지능 계산은 3층으로 구성된 네트워크를 이용하였으며 각 층은 30개의 neuron들로 구성하였다. 인공지능망의 입력 값은 나이, 수축기 혈압, 이완기 혈압, 심박수 값 (입력 값 4개)이고 출력 값은 혈관 저항값인 Ra이다. 머신러닝 차수를 높이면서 인공지능을 사용하지 않은 생리적 모델로부터 도출된 결과와 인공지능을 통하여 계산된 결과를 비교하였다. 개발된 인공지능계산을 이용한 생리시스템 모델은 대량의 표본집단에서 임상 검증에 기여할 것이다.

• Tunnel and Underground Space
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• v.14 no.3
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• pp.229-240
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• 2004

Coastal aquifers may serve as major sources fur freshwater. In many coastal aquifers, intrusion of seawater has become one of the major constraints imposed on groundwater utilization. The management of groundwater in coastal acquifers means making decision as to the pumping rate and the spatial distribution of wells. Several numerical techniques for flow and solute transport simulation can provide the means to achieve this goal. As a basic study to predict the intrusion of seawater in coastal phreatic aquifers, the coupled flow and solute transport analysis was conducted by use of the 3-D finite element code, SWICHA. In order to understand how the location and the shape of freshwater-seawater transition zone were affected by the boundary conditions and hydrogeologic variables, parametric study was carried out.

• Clean Technology
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• v.25 no.3
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• pp.206-222
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• 2019

Recently, various multiphase flows have been developed, and among them some models have been commercialized. However, most of them have been developed based on a pressure-based approach; therefore, various numerical difficulties were involved inherently. Accordingly, in order to overcome these numerical difficulties, a multiphase flow model, MultiPhaSe flow (MPS), following a fractional-flow based approach was developed. In this study, by combining a contaminant transport module describing an enhanced dissolution effect of a surfactant with MPS, a MultiPhaSe flow and TranSport (MPSTS) model was developed. The developed model was verified using the analytical solution of Clement. The MPSTS model can simulate the process of surfactant enhanced aquifer remediation including interphase mass transfer and contaminant transport in multiphase flow by using the coupled particle tracking method and Lagrangian-Eulerian method. In this study, a surfactant was used in a non aqueous phase liquid (NAPL) contaminated area, and the effect of hydro-geological heterogeneity in the layered media on remediation efficiency was studied using the developed model. According to the numerical simulation, when hydraulic conductivity in a lower layer is 10 times, 20 times, and 50 times larger than that in an upper layer, the concentration of dissolved diesel in the lower layer is much higher than that in the upper layer because the surfactant moves faster along the lower layer owing to preferential flow; thus, the surfactant enhances dissolution of residual non aqueous phase liquid in the lower layer.

• Journal of Korea Water Resources Association
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• v.50 no.6
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• pp.387-395
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• 2017

Sea level rise, accompanied by climate change, is expected to exacerbate seawater intrusion in the coastal groundwater system. As the salinity of saturated groundwater increases, salinity can increase even in the unsaturated soil above the groundwater surface, which may cause crop damage in the agricultural land. The other adverse impact of sea level rise is reduced unsaturated soil thicknesses. In this study, a composite model to assess impacts of sea level rise in coastal agricultural land is proposed. The composite model is based on the combined applications of a three dimensional model for simulating saltwater intrusion into the groundwater and a vertical one dimensional model for simulating unsaturated zone flow and transport. The water level and salinity distribution of groundwater are calculated using the three dimensional seawater intrusion model. At some uppermost nodes, where salinity are higher than the reference value, of the 3D mesh one dimensional unsaturated zone modeling is conducted along the soil layer between the ground water surface and the ground surface. A particular location is judged salinized when the concentration at the root-zone depth exceeds the tolerable salinity for ordinary crops. The developed model is applied to a hypothetical agricultural reclamation land. IPCC RCP 4.5 and 8.5 scenarios were used as sea level rise data. Results are presented for 2050 and 2100. As a result of the study, it is predicted that by 2100 in the climate change scenario RCP 8.5, there will be 7.8% increase in groundwater saltwater-intruded area, 6.0% increase of salinized soil area, and 1.6% in increase in water-logging area.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.115-124
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• 2006

The objectives of this paper are to develop the structural condition evaluation technique using Falling Weight Deflectometer deflections and propose the structural condition criteria for asphalt pavements. To figure out correlation between surface deflections and critical pavement responses, the synthetic database has been established using the finite element pavement structural analysis program. A regression approach was adopted to develop the pavement response model that can be used to compute the stresses and strains within pavement structure using the FWD deflections. Based on the pavement response model, the procedure for assessing the structural condition of pavement layers was proposed in this study. To validate the condition evaluation procedure for asphalt pavements, the FWD test, dynamic cone penetrometer test, and repeated triaxial compression test were conducted on 11 sections of national highway and 8 sections of local road. Test results indicate that the tensile strain at the bottom of AC layer and AC elastic modulus were good indicators for estimating the stiffness characteristics of AC layer. For subbase layer, the BDI value and compressive strain on top of the subbase layer were appropriate to predict the structural capacity of subbase layer. The BCI value and compressive strain on top of the subgrade were found to be good indicators for evaluating the structural condition of the subgrade. The evaluation criteria for structural condition in asphalt pavements was also proposed in this paper.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.3
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• pp.107-114
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• 2010

This study was undertaken to suggest a Pinus densiflora community planting model in the central cool temperate zone of Korea and nearby areas. For the purpose of this study, we surveyed various DBH classes of the P. densiflora community in Dangjin-gun, Choongchungnam-do. We surveyed the size of entire individuals in the 92 plots as well as surveyed the location of individuals in each tree layer and sub-tree layer(1/100 scale) of 44 plots using a quadrant method from young to old communities. As a result of analysis, the tree layer was growing well but the basal areas of the subtree layer were less than 10% compared with the tree-layer. This indicates the subtree layer is not in general growing well in the P. densiflora community. There were no significant patterns in the shrub layer. A P. densiflora community planting would consist of a tree layer and a shrub layer and the finding of growth patterns of the tree layer is significant. In order to make a model of the shrub layer, an additionally survey of another shrub layer is needed in a nearby planting area. Both regression models, 1) between tree layer DBHs and individuals per unit area, and 2) between individuals per unit area and shortest distances of individuals, can yield much information through study.

• Food Engineering Progress
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• v.14 no.1
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• pp.41-48
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• 2010

An optical method was introduced to investigate the dispersion stability of Saengshik beverages (SB) containing 3.7-11.7% Saengshik powder (SP). Time course changes in backscattering light flux (BSLF) from SB were monitored by a Turbiscan. BSLF in the bottom and top layers of SB increased by forming sediment and foam, respectively, while that in the middle layer decreased by clarifying. With SP levels, sedimentation in SB was retarded, but the height of total sedimentation layer was increased. A logarithmic model was developed to fit to the changes in BSLF with time, showing determination coefficients of 0.979-0.988. The levels of SP in SB influenced the migration speed of the clarification front as well as the numbers of separated layers; 2 layers in SB containing 3.7% SP, 3 in 5.7-9.7%, and 4 in 11.7%. Formation of clear layers started after 17-29 min and continued for 22-53 min. The clarification was retarded most in SB containing 7.7% SP, indicating the most stable SP level for the SB preparation.

• Journal of Korea Soil Environment Society
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• v.3 no.3
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• pp.3-10
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• 1998

Acid/Base buffer capacity of soil is very important in prediction of contaminant transport for its direct impact on pH change of the system composed of soil-contaminant-water, In this research, diffuse double layer theory as well as two layer electrostatic adsorption model are applied to develop a theoretical model of buffer capacity of soil. Model application procedures are presented as well. Buffer capacity of Georgia kaolinite and Milwhite kaolinite was measured by acid-base titration. Model prediction and experimental results are compared.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.465-470
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• 2024

The advancement of AI-based image generation technology has resulted in the creation of various images, emphasizing the need for technology capable of accurately discerning them. The amount of generated image data is limited, and to achieve high performance with a limited dataset, this study proposes a model for discriminating generated images using transfer learning. Applying pre-trained models from the ImageNet dataset directly to the CIFAKE input dataset, we reduce training time cost followed by adding three hidden layers and one output layer to fine-tune the model. The modeling results revealed an improvement in the performance of the model when adjusting the final layer. Using transfer learning and then adjusting layers close to the output layer, small image data-related accuracy issues can be reduced and generated images can be classified.