• Title/Summary/Keyword: 3D(three-dimensional)

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Application into Assessment of Liquefaction Hazard and Geotechnical Vulnerability During Earthquake with High-Precision Spatial-Ground Model for a City Development Area (도시개발 영역 고정밀 공간지반모델의 지진 시 액상화 재해 및 지반 취약성 평가 활용)

  • Kim, Han-Saem;Sun, Chang-Guk;Ha, Ik-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.5
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    • pp.221-230
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    • 2023
  • This study proposes a methodology for assessing seismic liquefaction hazard by implementing high-resolution three-dimensional (3D) ground models with high-density/high-precision site investigation data acquired in an area of interest, which would be linked to geotechnical numerical analysis tools. It is possible to estimate the vulnerability of earthquake-induced geotechnical phenomena (ground motion amplification, liquefaction, landslide, etc.) and their triggering complex disasters across an area for urban development with several stages of high-density datasets. In this study, the spatial-ground models for city development were built with a 3D high-precision grid of 5 m × 5 m × 1 m by applying geostatistic methods. Finally, after comparing each prediction error, the geotechnical model from the Gaussian sequential simulation is selected to assess earthquake-induced geotechnical hazards. In particular, with seven independent input earthquake motions, liquefaction analysis with finite element analyses and hazard mappings with LPI and LSN are performed reliably based on the spatial geotechnical models in the study area. Furthermore, various phenomena and parameters, including settlement in the city planning area, are assessed in terms of geotechnical vulnerability also based on the high-resolution spatial-ground modeling. This case study on the high-precision 3D ground model-based zonations in the area of interest verifies the usefulness in assessing spatially earthquake-induced hazards and geotechnical vulnerability and their decision-making support.

Research on Fashion Edutech XR Content Applying Skeuomorphism (스큐어모피즘을 적용한 패션 에듀테크 XR 콘텐츠 연구)

  • Hyang-Ja, Kim
    • Fashion & Textile Research Journal
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    • v.25 no.5
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    • pp.560-567
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    • 2023
  • This study aims to rediscover the industrial value of a borderless service in the hyper-connected era by producing fashion content at the forefront of the cultural industry as XR content and contributing to developing fashion content for edutech. The research method employed design aesthetic theory, while the empirical proposal utilized scientific knowledge information to build a framework for 3D convergence content. The characteristics of fashion content exhibitions that apply the neumorphism technique are as follows: The first is a virtual space that produces clothing culture by type. Africa, where dyeing and crafts are developed, selects a product-oriented exhibition type; Asia, where weaving and textiles are excellent, selects a random movement type; and Europe, where the evolution of clothing design over time is evident, selects a guided movement type to create a three-dimensional fashion edutech. The goal was to produce content. The second is creative reproducibility, which combines a new fashion design that embraces the aura of the original with a trendy sense. The realistic folk costume style of the original allowed for its implementation in the AR exhibition space using historical traditional style techniques such as weaving and textiles. The third is building organic, modular content. By designing and then saving/editing/arranging the basic VP zone for each style, learners and instructors can freely edit the content for each fashion class topic and create various presentations to ensure that it functions as non-face-to-face edutech content around the world.

Permeability Prediction of Gas Diffusion Layers for PEMFC Using Three-Dimensional Convolutional Neural Networks and Morphological Features Extracted from X-ray Tomography Images (삼차원 합성곱 신경망과 X선 단층 영상에서 추출한 형태학적 특징을 이용한 PEMFC용 가스확산층의 투과도 예측)

  • Hangil You;Gun Jin Yun
    • Composites Research
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    • v.37 no.1
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    • pp.40-45
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    • 2024
  • In this research, we introduce a novel approach that employs a 3D convolutional neural network (CNN) model to predict the permeability of Gas Diffusion Layers (GDLs). For training the model, we create an artificial dataset of GDL representative volume elements (RVEs) by extracting morphological characteristics from actual GDL images obtained through X-ray tomography. These morphological attributes involve statistical distributions of porosity, fiber orientation, and diameter. Subsequently, a permeability analysis using the Lattice Boltzmann Method (LBM) is conducted on a collection of 10,800 RVEs. The 3D CNN model, trained on this artificial dataset, well predicts the permeability of actual GDLs.

Two-Dimensional Lanthanum-BDC Coordination Polymer:Hydrothermal Synthesis and Structure of [La4(BDC)6(H2O)5](H2O)(BDC=benzene-1,3-dicaboxylate) (2차원 La-BDC 배위 고분자: [La4(BDC)6(H2O)5](H2O)의 수열합성 및 구조(BDC=benzene-1,3-dicaboxylate))

  • Kim, Hye Jin;Min, Dong Won;Heo, Hyun Su;Lee, Soon W.
    • Journal of the Korean Chemical Society
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    • v.45 no.6
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    • pp.507-512
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    • 2001
  • The hydrothermal reaction between lanthanum(Ⅲ) nitrate $(La(NO3)3${\cdot}$6H_2O)$ and benzene-1,3-dicarboxylic acid $(H_2BDC)$ in the presence of 1,2-bis(4-pyridyl)ethane gave a 2-D lanthnum-BDC coordination polymer with an empirical formula of $〔La_4$(BDC)_6(H_2O)_5$〕(H_2O)$ (1). X-ray structure analysis of compound 1 revealed that this polymer contains four distinct La metals. The three La metals are 7-coordinate with three different structures: a capped trigonal prism, a capped octahedron, and a pentagonal bipyramid. The remaining La metal has a 8-coordinate, square antiprismatic structure.

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Clinical validity and precision of deep learning-based cone-beam computed tomography automatic landmarking algorithm

  • Jungeun Park;Seongwon Yoon;Hannah Kim;Youngjun Kim;Uilyong Lee;Hyungseog Yu
    • Imaging Science in Dentistry
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    • v.54 no.3
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    • pp.240-250
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    • 2024
  • Purpose: This study was performed to assess the clinical validity and accuracy of a deep learning-based automatic landmarking algorithm for cone-beam computed tomography (CBCT). Three-dimensional (3D) CBCT head measurements obtained through manual and automatic landmarking were compared. Materials and Methods: A total of 80 CBCT scans were divided into 3 groups: non-surgical (39 cases); surgical without hardware, namely surgical plates and mini-screws (9 cases); and surgical with hardware (32 cases). Each CBCT scan was analyzed to obtain 53 measurements, comprising 27 lengths, 21 angles, and 5 ratios, which were determined based on 65 landmarks identified using either a manual or a 3D automatic landmark detection method. Results: In comparing measurement values derived from manual and artificial intelligence landmarking, 6 items displayed significant differences: R U6CP-L U6CP, R L3CP-L L3CP, S-N, Or_R-R U3CP, L1L to Me-GoL, and GoR-Gn/S-N (P<0.05). Of the 3 groups, the surgical scans without hardware exhibited the lowest error, reflecting the smallest difference in measurements between human- and artificial intelligence-based landmarking. The time required to identify 65 landmarks was approximately 40-60 minutes per CBCT volume when done manually, compared to 10.9 seconds for the artificial intelligence method (PC specifications: GeForce 2080Ti, 64GB RAM, and an Intel i7 CPU at 3.6 GHz). Conclusion: Measurements obtained with a deep learning-based CBCT automatic landmarking algorithm were similar in accuracy to values derived from manually determined points. By decreasing the time required to calculate these measurements, the efficiency of diagnosis and treatment may be improved.

Analysis of Hydraulic effects on Piers and Transverse Overflow Type Structures in Urban Stream (도시하천의 교각 및 횡단 월류형 구조물에 의한 수리영향 분석)

  • Yoon, Sun-Kwon;Chun, Si-Young;Kim, Jong-Suk;Moon, Young-Il
    • Journal of Korea Water Resources Association
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    • v.41 no.2
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    • pp.197-212
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    • 2008
  • Recently, stream flow analysis has been accomplished by one or two dimensional equations and was applied by simple momentum equations and fixed energy conservations which contain many condition limits. In this study, FLOW-3D using CFD (Computational Fluid Dynamics) was applied to stream flow analysis which can solve three dimensional RANS (Reynolds Averaged Navier-Stokes Equation) control equation to find out physical behaviors and the effect of hydraulic structures. Numerical simulation accomplished those results was compared by using turbulence models such as ${\kappa}-{\varepsilon}$, RNG (Renormalized Group) ${\kappa}-{\varepsilon}$ and LES (Large Eddy Simulation). Numerical analysis results have been illustrated by the turbulence energy effects, velocity of flow, water level pressure and eddy flows around the piers and transverse overflow type structures. These results will be able to used by basis data that catch hold of effects on long-term bed elevation changes, sediment accumulations, scours and water aggravations by removal of obsolete transverse over flow type structures in urban stream.

Effects of Strengthening Exercise using Vibrating Leg-press (진동 레그 프레스를 이용한 근력운동의 효과)

  • Hwang, S.H.;Cho, Y.G.;Sohn, R.H.;Kim, Y.H.;Kim, H.S.;Lim, D.H.
    • Journal of Biomedical Engineering Research
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    • v.30 no.3
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    • pp.221-225
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    • 2009
  • The purpose of this study was to investigate the biomechanical effects of an application of whole body vibration during strengthening exercise. Every participant performed four weeks exercise program using general leg-press versus vibrating leg-press. Participants did legpress exercise three sets of 25 repetitions with the load of 25 percent of 1RM during first week, three sets of 20 repetitions with 40 percent of 1RM during second week, three sets of 15 repetitions with 60 percents of 1RM during third week, and three sets of 15 repetitions with 80 percent of 1RM during last fourth week. The vibration(25Hz, 5mm) was applied only to the vibration exercise group. A three dimensional virtual lower extremity model for one of subject and virtual leg-press model were generated. The knee extensor muscle forces were analyzed using the virtual model and the knee joint torque(maximum extension torque) was measured using an isokinetic device. Calculated muscle forces were smaller in vibrating leg-press exercise than in general leg-press exercise. An increase of the maximum knee extension joint torque was 2.14 times larger approximately after the four week vibration leg-press exercise program was performed.

Numerical studies on flow-induced motions of a semi-submersible with three circular columns

  • Tian, Chenling;Liu, Mingyue;Xiao, Longfei;Lu, Haining;Wang, Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.599-616
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    • 2021
  • The semi-submersible with three circular columns is an original concept of efficient multifunctional platform, which can be used for marginal oil, gas field, and Floater of Wind Turbines (FOWT). However, under certain flow conditions, especially in uniform current with specific velocities, the eddies will alternatively form and drop behind columns, resulting in the fluctuating lift force and drag force. Consequently, the semi-submersible will subject to the Flow-Induced Motions (FIM). Based on the Detached Eddy Simulation (DES) method, the numerical studies were carried out to understand the FIM characteristics of the three-column semi-submersible at two different parameters, i.e., current incidences (0°, 30°, and 60°-incidences) and reduced velocities (4 ≤ Ur ≤ 14). The results indicate that the lock-in range of 6 ≤ Ur ≤ 10 for the transverse motions is presented, and the largest transverse non-dimensional nominal amplitude is observed at 60°-incidence, with a value of Ay/D = 0:481. The largest yaw amplitude Ayaw is around 3.0° at 0°-incidence in the range of 8 ≤ Ur ≤ 12. The motion magnitude is basically the same as that of a four-column semi-submersible. However, smaller responses are presented compared to those of the three-column systems revealing the mitigation effect of the pontoon on FIM.

Development of Videooculograph for Vestibular Function Test (전정 기능 평가를 위한 영상 안구 운동 측정 시스템의 개발)

  • 김수찬;남기창;이원선;김덕원
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.40 no.3
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    • pp.189-198
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    • 2003
  • Videooculography (VOG) is one of the eye-movement measurement methods used for objective evaluation of vestibule -ocular reflex. A key feature of VOG is to estimate accurately the center of pupil and ocular torsion with being less influenced by the upper eyelid droop, eyelashes, corneal reflection, and eye blinks. Especially, it Is important to find the accurate center of the pupil in 3-D VOG because the inaccurate pupil center causes significant errors on measuring torsional eye movement. A new algorithm was proposed to find the center of pupil which is a little influenced by factors mentioned above. In this study, real time three-dimensional VOG which can measure horizontal, vortical, torsional eye movements, and the diameter of pupil was implemented using the proposed method.

Synthesis, Characterization, Luminescence and Biological Activity of Two Lanthanide Complexes Involving Mixed Ligands

  • Ma, De-Yun;Guo, Hai-Fu;Qin, Liang;Xu, Jun
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2774-2780
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    • 2013
  • Two new isostructural dinuclear complexes, $Ln_2(4-cpa)_6(bpy)_2$ (Ln = Eu (1); Tb (2), 4-cpa = 4-chlorophenylacetate, bpy = 2,2'-bipyridine), have been hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. The lanthanide ions are bridged by two bidentate and two terdentate carboxylate groups to give centrosymmetric dimers with $Ln{\cdots}Ln$ separations of 3.967(2) and 3.956(3) ${\AA}$, respectively. Each metal atom is nine-coordinate and exhibits a distorted tricapped trigonal prismatic geometry. Three-dimensional fluorescence spectra show that both 1 and 2 emit bright red and green luminescence at room temperature, with long lifetimes of up to 0.369 ms (at 614 nm) and 0.432 ms (at 543 nm), respectively. Moreover, poor luminescence efficiency has been noted for complex 2. The 4-Hcpa ligand and complexes 1-2 have been screened for their phytogrowth-inhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-P-ethyl.