Hangseok Choi
Korea University
Porous mediumHeat exchangerSlope stability analysisConvectionBiot numberSeries (mathematics)GeologyEngineeringGroundwater flowSettlement (structural)Finite element methodTemperature gradientShieldMean squared errorF1 scoreConsolidation (soil)BoreholeArtificial intelligenceResidualConservation of massSoil scienceSoil waterBayesian inferenceComputational fluid dynamicsPedotransfer functionHuman settlementCurrent (stream)Test setDiscrete element methodThermal conductionGeneralizationPattern recognitionMesh generationPoromechanicsBoundary value problemCurve fittingLandslideGeotechnical engineeringUpstream (networking)Materials sciencePredictabilityRefrigerantThermalRange (statistics)Scale (descriptive set theory)Discontinuity (linguistics)SubseaTunnel constructionThermal response testTransient (oscillation)Polygon meshExcavationMathematicsStability (probability)Environmental scienceWater tableSequence learningComputer scienceEnsemble learningNumerical analysisComputer simulationHeat transferArtificial neural networkCompressible flowSlip (materials science)Early stoppingPearson product-moment correlation coefficientMechanicsReceiver operating characteristicMagnitude (mathematics)Hydraulic conductivityPorosityIntensity (heat transfer)Trough (meteorology)Logarithmic mean temperature differenceClassical mechanicsGroundwaterMechanical engineeringThrustConjugate gradient methodCompressibilityFluid dynamicsThermal conductivityReduction (complexity)
11Publications
5H-index
64Citations
Publications 11
Newest
#2Dongku Kim (KU: Korea University)H-Index: 5
#3Sangyeong Park (KU: Korea University)H-Index: 1
Last. Hangseok Choi (KU: Korea University)H-Index: 19
view all 4 authors...
Abstract In this study, ensemble learning was applied to develop a classification model capable of accurately estimating slope stability. Two prominent ensemble techniques—parallel learning and sequential learning—were applied to implement the ensemble classifiers. Additionally, for comparison, eight versatile machine learning algorithms were utilized to formulate the single-learning classification models. These classification models were trained and evaluated on the well-established global data...
7 CitationsSource
#1Dongseop Lee (Po: POSCO)H-Index: 1
#3Minkyu Kang (KU: Korea University)H-Index: 1
Last. Hangseok Choi (KU: Korea University)H-Index: 19
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Abstract A stepwise discrete element-finite element (DE/FE) combined numerical framework was proposed for efficiently estimating the effective thermal conductivity of spherical particulate media, which considers the thermal interaction of particle-to-particle and particle-to-pore filling material. The particulate composition was numerically modeled by the discrete element method (DEM), which was followed by a series of heat-transfer analyses formulated in the finite element method (FEM). In orde...
Source
#1Dongku Kim (KU: Korea University)H-Index: 5
#3Sangyeong Park (KU: Korea University)H-Index: 1
Last. Hangseok ChoiH-Index: 19
view all 5 authors...
Tunnel excavation in shallow soft ground conditions of urban areas experiences inevitable surface settlements that threaten the stability of nearby infrastructures. Surface settlements during shield TBM tunneling are related to a number of factors including geotechnical conditions, tunnel geometry and excavation methods. In this paper, a database collected from a construction section of Hong Kong subway was used to analyze the correlation of settlement-inducing factors and surface settlements mo...
1 CitationsSource
#2Dongku Kim (KU: Korea University)H-Index: 5
#3Yuemyung Yoon (KU: Korea University)H-Index: 1
Last. Hangseok Choi (KU: Korea University)H-Index: 19
view all 4 authors...
Abstract Approximate estimates employing the pedotransfer function (PTF) for predicting the soil-water characteristic curve have received general agreement among the geotechnical engineering society. Notably, the machine-learning-based PTFs (ML-PTFs) offer robust approaches with high prediction accuracy. This study analyzed the potential factors governing the prediction accuracy of the neural-network-based PTF (NN-PTF), which is one of the most popular ML-PTFs. Multiple analysis scenarios for th...
8 CitationsSource
#2Dongku Kim (KU: Korea University)H-Index: 5
#3In Mo Lee (KU: Korea University)H-Index: 20
Last. Hangseok Choi (KU: Korea University)H-Index: 19
view all 4 authors...
4 CitationsSource
#2Dongku Kim (KU: Korea University)H-Index: 5
#3Hyun Jun Choi (KU: Korea University)H-Index: 4
Last. Hangseok Choi (KU: Korea University)H-Index: 19
view all 5 authors...
Abstract This paper presents a simple numerical framework for infinite slope stability analysis under transient unsaturated seepage conditions. The advantage of the proposed framework, from the practical point of view, is to predict the variability in stability of partially saturated slope along with rainfall data. Moreover, the presented framework is adaptable to different types of soil-water characteristic curve (SWCC) models, hydraulic boundary conditions, and heterogeneity in soil properties...
18 CitationsSource
#2Hyobum Lee (KU: Korea University)H-Index: 4
#3Dongku Kim (KU: Korea University)H-Index: 5
Last. Hangseok Choi (KU: Korea University)H-Index: 19
view all 5 authors...
This paper examines the current procedure for determining the soil-water characteristic curve (SWCC) model with a particular focus on its application to slope stability analysis under transient unsaturated seepage conditions. A series of laboratory experiments was performed to determine the SWCC of different soils, ranging from high plasticity clay to silty sand, found across the Korean Peninsula. The experimental results were utilized to identify the suitable SWCC model for each soil type based...
7 CitationsSource
#2Hyun Jun Choi (KU: Korea University)H-Index: 4
#3Dongseop Lee (KU: Korea University)H-Index: 8
Last. Hangseok Choi (KU: Korea University)H-Index: 19
view all 5 authors...
In this study, a hydraulic-mechanical (H-M) coupling model was implemented, which considers porous media as a deforming porous continuum where fluid flow is taken into account. The primary variables are the time-dependent pore pressure and displacement of the solid skeleton. Physical laws, including the linear momentum balance and mass conservation, are applied to describe the corresponding processes as mechanics and fluid flow occurring within the porous media during the consolidation progress....
8 CitationsSource
#1Sangwoo Park (KU: Korea University)H-Index: 10
#2Seokjae Lee (KU: Korea University)H-Index: 7
Last. Hangseok ChoiH-Index: 19
view all 5 authors...
Groundwater flow is one of the most important factors for the design of a ground heat exchanger (GHEX) since the thermal environment of the ground around the buried GHEX is significantly affected by heat convection due to the groundwater flow. Several preceding studies have been conducted to develop analytical solutions to the heat transfer model of GHEX with consideration of groundwater flow. One of these solutions is the combined heat transfer model of conduction and convection. However, the d...
10 CitationsSource
#1Hyun Jun Choi (KU: Korea University)H-Index: 4
#2Sangwoo Park (KU: Korea University)H-Index: 10
Last. Hangseok Choi (KU: Korea University)H-Index: 19
view all 6 authors...
Summary This paper proposes an optimum operation method for open-loop ground heat exchangers (GHEX) considering the subsurface temperature gradient. A series of thermal response tests and artificial heating/cooling operations was carried out along with monitoring temperatures in the standing column well. The underground temperature naturally increases with depth, but a switch between the cooling and heating modes can alter the temperature distribution. The effect of the mode change was evaluated...
4 CitationsSource