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image-based modelling FROM UNMANNED AERIAL VEHICLE (UAV) PHOTOGRAMMETRY: AN EFFECTIVE, LOW-COST TOOL FOR ARCHAEOLOGICAL APPLICATIONS

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ARCHAEOMETRY 2015年第1期57卷 128-145页

作者： Fernandez-Hernandez, J. Gonzalez-Aguilera, D. Rodriguez-Gonzalvez, P. Mancera-Taboada, J. Univ Salamanca Dept Cartog & Land Engn C Hornos Caleros 50 Avila 05003 Spain

The recording and 3D modelling of complex archaeological sites is usually associated with high capital and logistical costs, because the data acquisition must be performed by specialists using expensive surveying sensors (i.e., terrestrial laser scanners, robotic total stations and/or ground-penetrating radar). This paper presents a novel, low-cost, user-friendly photogrammetric tool for generating high-resolution and scaled 3D models of complex sites. The results obtained with unmanned aerial vehicle (UAV) photogrammetry of an archaeological site indicate that this approach is semi-automatic, inexpensive and effective, and that it guarantees quality.

关键词： Unmanned aerial vehicle (UAV) archaeology software development image-based modelling photogrammetry computer vision

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image-based finite element modelling of fibre dynamics in polyester staple spun yarns

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COMPOSITES SCIENCE AND TECHNOLOGY 2025年 261卷

作者： Zhang, Haoqi Jabbar, Abdul Li, Aonan Wang, Xinxin Yang, Dongmin Tausif, Muhammad Sun Yat Sen Univ Sch Adv Mfg Shenzhen 518107 Guangdong Peoples R China Univ Edinburgh Inst Mat & Proc Sch Engn Edinburgh EH9 3FB Scotland Univ Leeds Sch Design Leeds LS2 9JT England Natl Text Univ Dept Text Engn Faisalabad 37610 Pakistan Cent South Univ Sch Traff & Transportat Engn Changsha 410075 Hunan Peoples R China

This paper introduces an innovative finite element (FE) modelling approach for fibre dynamics in a staple spun yarn based on the geometrical model derived from X-ray microcomputed tomography (mu CT) images. The FE model retains crucial in situ information on fibre anisotropy, length, and continuity while employing advanced stitched scanning technique to reconstruct a 15 mm yarn length containing individual fibres with similar to 10 mu m diameter. The research focuses on 100 % polyethylene terephthalate (PET) staple ring-spun yarn as a case study, conducting both single fibre and yarn tensile tests to characterise material properties and validate the FE model, respectively. Beyond examining the mechanical response at the yarn level, the model facilitates the investigation of individual fibre's tensile stress, frictional forces, and extent of migration, thereby enhancing the understanding of fibre interactions during yarn tensile loading. Furthermore, the model enables parametric studies through manipulation of inter-fibre friction coefficients allowing assessment of their impact on overall mechanical behaviour. This innovative modelling approach demonstrates significant potential for exploring the constitutive and failure mechanisms for formation of microplastics from textiles and textile materials in general as well as fibre-reinforced composites. It addresses the critical research gaps in simulating anisotropic behaviours of materials containing textile fibres, paving the way for advanced material design and analysis.

关键词： Finite element method image-based modelling X-ray microcomputed tomography (mu CT) Staple spun yarn Microplastics

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Stochastic multi-scale prediction on the apparent elastic moduli of trabecular bone considering uncertainties of biological apatite (BAp) crystallite orientation and image-based modelling

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COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING 2015年第2期18卷 162-174页

作者： Basaruddin, Khairul Salleh Takano, Naoki Nakano, Takayoshi Keio Univ Grad Sch Sci & Technol Yokohama Kanagawa 2238522 Japan Keio Univ Dept Mech Engn Yokohama Kanagawa 2238522 Japan Osaka Univ Div Mat & Mfg Sci Suita Osaka 5650871 Japan Univ Malaysia Perlis Sch Mechatron Engn Ulu Pauh 02600 Perlis Malaysia

An assessment of the mechanical properties of trabecular bone is important in determining the fracture risk of human bones. Many uncertainty factors contribute to the dispersion of the estimated mechanical properties of trabecular bone. This study was undertaken in order to propose a computational scheme that will be able to predict the effective apparent elastic moduli of trabecular bone considering the uncertainties that are primarily caused by image-based modelling and trabecular stiffness orientation. The effect of image-based modelling which focused on the connectivity was also investigated. A stochastic multi-scale method using a first-order perturbation-based and asymptotic homogenisation theory was applied to formulate the stochastically apparent elastic properties of trabecular bone. The effective apparent elastic modulus was predicted with the introduction of a coefficient factor to represent the variation of bone characteristics due to inter-individual differences. The mean value of the predicted effective apparent Young's modulus in principal axis was found at approximately 460MPa for respective 15.24% of bone volume fraction, and this is in good agreement with other experimental results. The proposed method may provide a reference for the reliable evaluation of the prediction of the apparent elastic properties of trabecular bone.

关键词： image-based modelling uncertainties stochastic multi-scale analysis apparent elastic moduli trabecular bone

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Influence of dental restorations and mastication loadings on dentine fatigue behaviour: image-based modelling approach

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JOURNAL OF DENTISTRY 2015年第5期43卷 556-567页

作者： Vukicevic, Arso M. Zelic, Ksenija Jovicic, Gordana Djuric, Marija Filipovic, Nenad Univ Kragujevac Fac Engn Kragujevac 34000 Serbia Bioengn Res & Dev Ctr Kragujevac Kragujevac 34000 Serbia Univ Belgrade Sch Med Inst Anat Lab Anthropol Belgrade 11000 Serbia

Objectives: The aim of this study was to use Finite Element Analysis (FEA) to estimate the influence of various mastication loads and different tooth treatments (composite restoration and endodontic treatment) on dentine fatigue. The analysis of fatigue behaviour of human dentine in intact and composite restored teeth with root-canal-treatment using FEA and fatigue theory was performed. Methods: Dentine fatigue behaviour was analysed in three virtual models: intact, composite restored and endodontically-treated tooth. Volumetric change during the polymerization of composite was modelled by thermal expansion in a heat transfer analysis. Low and high shrinkage stresses were obtained by varying the linear shrinkage of composite. Mastication forces were applied occlusally with the load of 100, 150 and 200 N. Assuming one million cycles, Fatigue Failure Index (FFI) was determined using Goodman's criterion while residual fatigue lifetime assessment was performed using Paris-power law. Results: The analysis of the Goodman diagram gave both maximal allowed crack size and maximal number of cycles for the given stress ratio. The size of cracks was measured on virtual models. For the given conditions, fatigue-failure is not likely to happen neither in the intact tooth nor in treated teeth with low shrinkage stress. In the cases of high shrinkage stress, crack length was much larger than the maximal allowed crack and failure occurred with 150 and 200 N loads. The maximal allowed crack size was slightly lower in the tooth with root canal treatment which induced somewhat higher FFI than in the case of tooth with only composite restoration. Conclusions: Main factors that lead to dentine fatigue are levels of occlusal load and polymerization stress. However, root canal treatment has small influence on dentine fatigue. Clinical significance: The methodology proposed in this study provides a new insight into the fatigue behaviour of teeth after dental treatments. Furthermore, it esti

关键词： Human dentine image-based modelling Finite element method Fatigue Mastication

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Automatic micro-scale modelling and evaluation of effective properties of highly porous ceramic matrix materials using the scaled boundary finite element method

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COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2024年 419卷

作者： Tian, Xinran Birk, Carolin Du, Chengbin Ooi, Ean Tat Hohai Univ Dept Engn Mech Nanjing Peoples R China Univ Duisburg Essen Inst Stat & Dynam Tragwerke D-45141 Essen Germany Federat Univ Australia Inst Innovat Sci & Sustainabil Future Reg Res Ctr Ballarat Vic 3350 Australia

This paper presents an approach to the numerical estimation of effective properties of highly porous materials based on the scaled boundary finite element method (SBFEM). The latter can be formulated on quadtree meshes with hanging nodes and thus facilitates the efficient mesh generation and analysis of a large number of randomly created samples. To generate the corresponding Representative Volume Elements (RVEs), an improved Random Sequential Addition (RSA) method with overlap is used. Moreover, an alternative image-based digital matrix method for generating random assemblies of circular particles of the same size is proposed. In addition, a modified smoothing algorithm to treat the staircase boundaries present in a quadtree mesh is developed in order to accurately and efficiently capture the sinter -neck features of overlapping circular particles. The proposed image-based mesh generation and analysis procedure is used to evaluate the relationship between microstructural parameters and effective Young's modulus considering a large number of samples. In this context, a new dimensionless morphological parameter Nfc is proposed. The latter represents the morphology and connectivity of voids and is shown to be a useful indicator with respect to the effective elastic properties of highly porous ceramic matrix material.

关键词： Effective properties Ceramic matrix Porous media image-based modelling Scaled boundary finite element method

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modelling heterogeneous coal-rock (HCR) failure patterns under dynamic impact loads using image-based finite element (FE) and discrete element (DE) model

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POWDER TECHNOLOGY 2020年 360卷 673-682页

作者： Zheng, Kehong Qiu, Bingjing Wang, Zhenyu Li, Jianping Gao, Kuidong Zhejiang Univ Coll Civil Engn & Architecture Yuhangtang Rd 866 Hangzhou 310058 Zhejiang Peoples R China China Univ Min & Technol Coll Mech & Elect Engn Xuzhou 221116 Jiangsu Peoples R China Shandong Univ Sci & Technol Coll Mech & Elect Engn Qingdao Shandong Peoples R China

The paper described two different numerical 3D mesoscopic approaches (the meso-scale image-based FE and DE model) for quantitative and qualitative characterization of the dynamic impact mechanical behavior of HCR. The 3D meso-structure of Ha in calculations, which was directly obtained from real coal rock specimen using nondestructive XCT techniques, was modelled as a random heterogeneous two-phase material composed of coal and gangue respectively. Dynamic impact loading in three directions (x-, y-, and z-axis) were modelled to investigate the 3D meso-structure and different input energies effects on failure patterns of HCR The very different qualitative and quantitative results demonstrated that the spatial distribution of mineral phases, loading directions and input energies have pronounced influenced on material strength as well as failure patterns of heterogeneous rock materials. The XCT image-based numerical model proved to be an effective tool that gives insights into the mesodeformation mechanisms of HCR undergoing dynamic impact failure behavior. (C) 2019 Published by Elsevier B.V.

关键词： Heterogeneous coal-rock (HCR) Impact loads X-ray computed tomography (XCT) image-based modelling Failure pattern

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Identifiability and model selection frameworks for models of high-grade glioma response to chemoradiation

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PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES 2025年第2293期383卷 20240212页

作者： Hiremath, Khushi C. Atakishi, Kenan Lima, Ernesto A. B. F. Farhat, Maguy Panthi, Bikash Langshaw, Holly Shanker, Mihir D. Talpur, Wasif Thrower, Sara Goldman, Jodi Chung, Caroline Yankeelov, Thomas E. Hormuth II, David A. Univ Texas Austin Dept Biomed Engn Austin TX 78712 USA Univ Texas Austin Texas Adv Comp Ctr Austin TX 78712 USA Univ Texas Austin Dept Diagnost Med Austin TX 78712 USA Univ Texas Austin Dept Oncol Austin TX 78712 USA Univ Texas Austin Oden Inst Computat Engn & Sci Austin TX 78712 USA MD Anderson Canc Ctr Dept Radiat Oncol Houston TX 77030 USA MD Anderson Canc Ctr Dept Imaging Phys Houston TX 77030 USA Univ Queensland Fac Med Brisbane Qld 4072 Australia Univ Texas Austin Livestrong Canc Inst Austin TX 78712 USA

We have developed a family of biology-based mathematical models of high-grade glioma (HGG), capturing the key features of tumour growth and response to chemoradiation. We now seek to quantify the accuracy of parameter estimation and determine, when given a virtual patient cohort, which model was used to generate the tumours. In this way, we systematically test both the parameter and model identifiability. Virtual patients are generated from unique growth parameters whose growth dynamics are determined by the model family. We then assessed the ability to recover model parameters and select the model used to generate the tumour. We then evaluated the accuracy of predictions using the selected model at four weeks post-chemoradiation. We observed median parameter errors from 0.04% to 72.96%. Our model selection framework selected the model that was used to generate the data in 82% of the cases. Finally, we predicted the growth of the virtual tumours using the selected model resulting in low error at the voxel-level (concordance correlation coefficient (CCC) ranged from 0.66 to 0.99) and global level (percentage error in total tumour cellularity ranged from -12.35% to 0.07%). These results demonstrate the reliability of our framework to identify the most appropriate model under noisy conditions expected in the clinical *** article is part of the theme issue 'Uncertainty quantification for healthcare and biological systems (Part 2)'.

关键词： mathematical oncology reaction-diffusion model selection image-based modelling

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Exploring the role of carbon binder domain morphology in enhancing the electrochemical performance of Li-ion battery

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JOURNAL OF POWER SOURCES 2025年 641卷

作者： Sun, Wei Huang, Chun Imperial Coll London Dept Mat London SW7 2AZ England Quad One Faraday Inst Becquerel Ave Harwell Campus Didcot OX11 0RA England Appleton Lab Res Complex Harwell Didcot OX11 0FA England

The electrochemical performance of Li-ion batteries (LIBs) is significantly influenced by electrode microstructure. The carbon and binder domain (CBD) plays an important role as it supports electronic conduction and maintains mechanical integrity. Despite its importance, the impact of CBD morphology on electrochemical performance remains poorly understood. One of the reasons is that CBD requires higher resolution to resolve the nanostructures, and techniques such as most X-ray computed tomography (XCT) machine cannot resolve CBD. This study establishes a workflow that incorporates active material (AM) particles obtained from XCT with numerically generated CBD morphology to build a 3D image-based and physics-resolved model to predict its electrochemical performance. Our model considers both explicit and implicit configurations of dense and nanoporous CBD during the electrochemical modelling process. Results indicate that the interface between AM and electrolyte significantly limits discharge capacity under explicit dense CBD configurations. In contrast, filmcoating-like nanoporous CBD could enhance LIB longevity due to locally homogeneous lithiation in AM particles. Our findings also suggest that Li-ion transport is a major limitation in achieving higher (dis)charge rate capacities (5C) under implicit CBD considerations. This study highlights the crucial role of CBD morphology in optimising electrode design for improved battery performance.

关键词： Carbon binder domain Electrode Microstructure Ionic transport image-based modelling

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GeoCode: Interpretable Shape Programs

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COMPUTER GRAPHICS FORUM 2025年第1期44卷

作者： Pearl, Ofek Lang, Itai Hu, Yuhua Yeh, Raymond A. Hanocka, Rana Tel Aviv Univ Sch Elect Engn Tel Aviv Israel Univ Chicago Dept Comp Sci Chicago IL 60611 USA Purdue Univ Dept Comp Sci W Lafayette IN USA

The task of crafting procedural programs capable of generating structurally valid 3D shapes easily and intuitively remains an elusive goal in computer vision and graphics. Within the graphics community, generating procedural 3D models has shifted to using node graph systems. They allow the artist to create complex shapes and animations through visual programming. Being a high-level design tool, they made procedural 3D modelling more accessible. However, crafting those node graphs demands expertise and training. We present GeoCode, a novel framework designed to extend an existing node graph system and significantly lower the bar for the creation of new procedural 3D shape programs. Our approach meticulously balances expressiveness and generalization for part-based shapes. We propose a curated set of new geometric building blocks that are expressive and reusable across domains. We showcase three innovative and expressive programs developed through our technique and geometric building blocks. Our programs enforce intricate rules, empowering users to execute intuitive high-level parameter edits that seamlessly propagate throughout the entire shape at a lower level while maintaining its validity. To evaluate the user-friendliness of our geometric building blocks among non-experts, we conduct a user study that demonstrates their ease of use and highlights their applicability across diverse domains. Empirical evidence shows the superior accuracy of GeoCode in inferring and recovering 3D shapes compared to an existing competitor. Furthermore, our method demonstrates superior expressiveness compared to alternatives that utilize coarse primitives. Notably, we illustrate the ability to execute controllable local and global shape manipulations. Our code, programs, datasets and Blender add-on are available at .

关键词： curves and surfaces image-based modelling modelling modelling interfaces

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Statistical Effective Diffusivity Estimation in Porous Media Using an Integrated On-site Imaging Workflow for Synchrotron Users

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TRANSPORT IN POROUS MEDIA 2023年第1期150卷 71-88页

作者： Le Houx, James Ruiz, Siul Fletcher, Daniel McKay Ahmed, Sharif Roose, Tiina Diamond Light Source Harwell Sci & Innovat CampusFermi Ave Didcot OX11 0DE Oxon England Univ Southampton Fac Engn & Phys Sci Univ Rd Southampton SO17 1BJ Hants England Scotlands Rural Coll Rural Econ Environm & Soc West Mains Rd Edinburgh EH9 3JG Scotland

Transport in porous media plays an essential role for many physical, engineering, biological and environmental processes. Novel synchrotron imaging techniques and image-based models have enabled more robust quantification of geometric structures that influence transport through the pore space. However, image-based modelling is computationally expensive, and end users often require, while conducting imaging campaign, fast and agile bulk-scale effective parameter estimates that account for the pore-scale details. In this manuscript we enhance a pre-existing image-based model solver known as OpenImpala to estimate bulk-scale effective transport parameters. In particular, the boundary conditions and equations in OpenImpala were modified in order to estimate the effective diffusivity in an imaged system/geometry via a formal multi-scale homogenisation expansion. Estimates of effective pore space diffusivity were generated for a range of elementary volume sizes to estimate when the effective diffusivity values begin to converge to a single value. Results from OpenImpala were validated against a commercial finite element method package COMSOL Multiphysics (abbreviated as COMSOL). Results showed that the effective diffusivity values determined with OpenImpala were similar to those estimated by COMSOL. Tests on larger domains comparing a full image-based model to a homogenised (geometrically uniform) domain that used the effective diffusivity parameters showed differences below 2 % error, thus verifying the accuracy of the effective diffusivity estimates. Finally, we compared OpenImpala's parallel computing speeds to COMSOL. OpenImpala consistently ran simulations within fractions of minutes, which was two orders of magnitude faster than COMSOL providing identical supercomputing specifications. In conclusion, we demonstrated OpenImpala's utility as part of an on-site tomography processing pipeline allowing for fast and agile assessment of porous media processes and to guide

关键词： Porous media image-based modelling Homogenisation Numerical methods

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