Applied Mathematical Modelling最新文献

{"title":"Analytical and experimental investigation of vibration response for the cracked fluid-filled thin cylindrical shell under transport condition","authors":"Tong Wang ,&nbsp;Dapeng Tan ,&nbsp;Yueqiao Hou ,&nbsp;Chengyan Wang ,&nbsp;Jinwei Cheng ,&nbsp;Wenlong Song","doi":"10.1016/j.apm.2025.115969","DOIUrl":"10.1016/j.apm.2025.115969","url":null,"abstract":"<div><div>Adverse conditions induce surface cracks in fluid-filled thin cylindrical shells, thereby diminishing their mechanical properties and load-bearing capacity. However, due to the discontinuity in vibration characteristics near the cracks and the strong coupling during the transport process, the free vibration response solution and state recognition oriented to the fluid-filled thin cylindrical shell containing a surface crack still face significant challenges. To address the above issues, a free vibration response solution method for fluid-filled thin cylindrical shell containing a surface crack based on Linear Spring Model and linear potential flow theory is proposed, which elucidates the interaction mechanism within the fluid-shell-crack coupling state and establishes a quantitative relationship between these coupling parameters and vibration response characteristics. Subsequently, a natural frequency isoline-based state recognition method is introduced to achieve unified identification of crack morphology and fluid state. Finally, a multi-channel LMS vibration test platform is built, and the error between analytical and experimental results is less than 4 %, thereby corroborating the accuracy and validity of the proposed vibration response solution method. The research findings indicate that both surface cracks and internal fluid contribute to the reduction in natural frequency, with the crack angle being the primary factor. Additionally, it is observed that apart from internal fluid velocity, all parameters exhibit extreme values near a length ratio of L<em>/R</em> = 10.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115969"},"PeriodicalIF":4.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143353519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bayesian model updating in an active Kriging-based metamodeling framework","authors":"Partha Sengupta ,&nbsp;Subrata Chakraborty","doi":"10.1016/j.apm.2025.115981","DOIUrl":"10.1016/j.apm.2025.115981","url":null,"abstract":"<div><div>A Bayesian model updating approach is proposed where an active Kriging-based metamodel efficiently approximates the expensive-to-evaluate posterior probability density. Unlike the usual Kriging-based model updating approach, the present study competently approximates the modal responses of different natures and dimensions. In detail, an active learning function is proposed where the computationally intensive expectation function evaluation in the usual least improvement function is modified with an expected improvement technique. For computational efficiency in constructing the Kriging model, the unknown modal coordinates are obtained using an improved model reduction technique to evade complete model evaluations. The proposed Kriging model approximates the posterior probability density of model parameters so that each term of the learning function is updatable. This is likely to improve the accuracy of the learning function. Finally, a sampling strategy using affine invariance within the Transitional Markov Chain Monte Carlo technique estimates a multi-dimensional scaling factor that accounts for the mode shapes and frequencies of different natures and dimensions. The proposed algorithm is illustrated numerically by considering a realistic ten-storey building and a multi-span curved bridge. The estimated model parameters by the proposed approach at various noise levels indicate its accuracy and efficiency compared to existing approaches.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115981"},"PeriodicalIF":4.4,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A geometric nonlinear multi-material topology optimization method based on univariate combination interpolation scheme","authors":"Haitao Liao,&nbsp;Wenhao Yuan,&nbsp;Mengdi Qin,&nbsp;Yixing Huang","doi":"10.1016/j.apm.2025.115970","DOIUrl":"10.1016/j.apm.2025.115970","url":null,"abstract":"<div><div>The multi-material topology optimization design is a significant area of research, especially when considering geometric nonlinearity. Traditional topology optimization methods are primarily developed based on linear problems and often face the issue where the number of design variables increases proportionally with the number of candidate materials. Additionally, the interphases obtained using stair-step interpolation formulations are often enclosed within adjacent materials, leading to impractical designs and suboptimal results. To address these challenges, a univariate combination interpolation-based multi-material topology optimization method is proposed and applied to multi-material topology optimization considering geometric nonlinearity. Firstly, the univariate characteristic function is utilized to map the single design variable field into multiple topology density fields, each represented by a distinct topology density function. These topology density fields are then processed using a smoothing algorithm based on the convolution-based density filtering method. Subsequently, a physical density field is established through a regularized Heaviside function. By integrating the univariate characteristic function with the convolution density filtering technique, a series of topology density functions with adequate smoothness and continuity is embedded within the Discrete Material Optimization (DMO) interpolation formulation, forming the composite interpolation model. Due to the non-convexity of the topology optimization problem, a continuation strategy for penalty parameter and smoothness parameter adaptive adjustment is introduced to enhance the robustness and optimization efficiency of the algorithm. The Method of Moving Asymptotes (MMA) gradient optimization algorithm is employed to update the design variables iteratively. Finally, a series of two-dimensional and three-dimensional numerical examples considering geometric nonlinearity is presented, with the objective of minimizing compliance under volume constraints. The results indicate that the proposed method effectively combines the advantages of the DMO method with the univariate characteristic function in multi-material topology optimization considering geometric nonlinearity, which successfully addresses the challenges posed by interphase materials between stiff and compliant materials. Moreover, the number of design variables is independent of the number of candidate materials, demonstrating the successful extension of the proposed method to problems involving geometric nonlinearity.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115970"},"PeriodicalIF":4.4,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of geographically-targeted vaccinations during the 2018-2020 Kivu Ebola outbreak","authors":"Suliman Jamiel M. Abdalla ,&nbsp;Keshlan S. Govinder ,&nbsp;Faraimunashe Chirove","doi":"10.1016/j.apm.2025.115972","DOIUrl":"10.1016/j.apm.2025.115972","url":null,"abstract":"<div><div>The 2018–2020 Ebola virus disease (EVD) outbreak in the Democratic Republic of Congo (DR Congo) was the second-largest in history, mainly because of security challenges and community mistrust. This study evaluates the impact of geographically targeted vaccinations (GTVs) as a complementary strategy when traditional measures—contact tracing, ring vaccinations, and antiviral treatments—are insufficient. We develop a novel mathematical model, incorporating key factors such as transmission from the deceased, heterogeneity in susceptibility, migration patterns, and control measures. Numerical simulations reveal that while traditional control measures substantially reduce cumulative cases to 3500 within one year, compared to over 10 million cases without intervention, population movement into high-infection areas intensifies transmission by increasing the pool of susceptible individuals. This highlights the need to reduce the flow of population into high-risk regions. Sensitivity analysis identifies key parameters, including effective contact rate and the rate of movement into areas with high infections, as critical epidemic drivers. Contour plots demonstrate that GTVs in areas with high infections significantly reduce the spread of EVD. Model findings emphasise integrating GTVs and population flow management with traditional strategies to strengthen outbreak responses in conflict-prone regions.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115972"},"PeriodicalIF":4.4,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of the improved boundary knot and fundamental solutions methods for complex multi-connected Helmholtz-type equations","authors":"M. Lei ,&nbsp;T. Li ,&nbsp;H. Meng","doi":"10.1016/j.apm.2025.115971","DOIUrl":"10.1016/j.apm.2025.115971","url":null,"abstract":"<div><div>In this paper, the performance of the proposed improved boundary knot method and the method of fundamental solutions in solving Helmholtz-type equations within multi-connected domains is investigated. The method of fundamental solutions typically requires multiple layers of source points, resulting in a tedious and time-consuming process of optimizing their distribution. Although the traditional boundary knot method circumvents this challenge by using non-singular general solutions, it often struggles to deliver satisfactory accuracy for complex problems. To address these limitations, the improved boundary knot method that incorporates a ghost points technique is proposed. These ghost points can be positioned flexibly in various configurations, such as circular or cloud-like patterns, located either inside or outside the problem domain. To further optimize the ghost points' position, we study the influence of the free parameter ghost radius <em>R</em>, where two strategies, namely the effective condition number and economic effective condition number, are employed and analyzed. Finally, various examples demonstrate that the improved boundary knot method outperforms the conventional version. Compared to the method of fundamental solutions, it simplifies the placement of source/ghost nodes while maintaining accuracy. Code is available at <span><span>https://github.com/LT306/one/tree/main/IBKM</span><svg><path></path></svg></span></div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115971"},"PeriodicalIF":4.4,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Baseline-free localization and quantification of structural damage using spectral response","authors":"Sayandip Ganguly,&nbsp;Koushik Roy","doi":"10.1016/j.apm.2025.115967","DOIUrl":"10.1016/j.apm.2025.115967","url":null,"abstract":"<div><div>Localization of damage using modal parameter changes has been the focus of research in many recent studies. Efforts have also been made to establish an analytical correlation between changes in modal response from the healthy state and the eventual reduction in stiffness. Prevailing methodologies predominantly integrate baseline responses to attain these objectives. However, non-availability of pre-recorded data practically complicates the application of reference state-based damage investigations. In the present study, a novel formulation is proposed for evaluation of existing crack with spectral responses of only damaged state. Efficiency of derived mathematical formulation is numerically verified on a shear building with several damage cases. Robustness of the method is then examined through noise sensitivity analysis. Further, an experimental investigation is conducted on a reduced scale in-house steel building model. Two cases of damage severity are examined by introducing reduced cross-sectional member at the damage location. Finally, practical applicability of the method is explored with a case study using real post-damage data of a 7-story building. Significant accuracy evolved from these exhaustive analyses, highlights the potential of present baseline-free damage quantification technique. This instantaneous data-based methodology can further be extended in future to assess residual useful life of a structure.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115967"},"PeriodicalIF":4.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ACPDNLS: Adaptive convexity preserving double nonzero level set for cardiac MR image segmentation","authors":"Ji Li ,&nbsp;Aiwen Liu ,&nbsp;Yan Wang","doi":"10.1016/j.apm.2025.115975","DOIUrl":"10.1016/j.apm.2025.115975","url":null,"abstract":"<div><div>Cardiovascular disease has become a major cause of global mortality. Clinically, quantitative assessment of cardiac MR image is usually used to determine the type and severity of cardiovascular disease, in which segmentation of cardiac MR image is a fundamental but important step. However, due to the inhomogeneity and special anatomical structures, accurate segmentation of cardiac MR images is still a challenging task. This paper proposes a double nonzero level set model for the segmentation of cardiac MR images, incorporating an adaptive convexity preserving mechanism and an improved distance regularization term. The double nonzero level set is capable of simultaneously and rapidly segmenting the left ventricle (LV) and right ventricle (RV). The adaptive convexity preserving mechanism guarantees that the segmentation of LV encompasses the cavity, papillary muscles and trabeculae while preserving convexity to meet clinical criteria. In addition, it ensures that RV retains its inherent physiological form, i.e. crescent-like shape. The improved distance regularization term effectively eliminates the need for reinitialization of double level set functions. The proposed model is evaluated on the data of ACDC MICCAI 2017. Experimental results show that in the end-diastolic (ED) and end-systolic (ES) phases, the mean Dice coefficients of LV segmentation are 0.961 (ED) and 0.936 (ES), with mean Hausdorff distances of 4.89 (ED) and 5.79 (ES), while the mean Dice coefficients of RV segmentation are 0.952 (ED) and 0.914 (ES), with mean Hausdorff distances of 8.52 (ED) and 9.60 (ES). The prominent advantage of our model is that, without the requirement of manual annotation and tedious training, it exhibits segmentation accuracy and robustness comparable to deep learning-based cardiac segmentation models. Especially, the segmentation accuracy of RV surpasses that of current state-of-the-art models.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115975"},"PeriodicalIF":4.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal control of stochastic fractional rumor propagation model in activity-driven networks","authors":"Haojie Hou ,&nbsp;Youguo Wang ,&nbsp;Qiqing Zhai ,&nbsp;Xianli Sun","doi":"10.1016/j.apm.2025.115968","DOIUrl":"10.1016/j.apm.2025.115968","url":null,"abstract":"<div><div>Activity-driven networks have become a key paradigm for studying the time evolution of stochastic networked systems. Consider the fact that individuals in activity-driven networks have some degree of memory, and they assess the credibility of current information based on their prior knowledge. In addition, the number of potential participants in rumor propagation dynamically changes, and the actual network topology driven by activity is affected by environmental noise. Previous studies have overlooked the stochastic nature of activities and instead generalized the system dynamics with constant parameters. To fill this gap, we propose a stochastic fractional-order rumor propagation model that takes into account the variation of node activity rates and conduct an optimal control study. We utilize Caputo fractional-order derivatives to depict memorability, model stochasticity using standard Wiener processes, and formulate fractional-order stochastic differential equations to describe the dynamics of rumor propagation on activity-driven networks. Firstly, stochastic fractional-order equations with consistent unit dimensions are derived. Secondly, the existence and uniqueness of the solution to the stochastic fractional-order model are proven using Picard's iterative method, and the issue of rumor extinction is investigated. Then, Pontryagin's minimum principle and optimal control theory are applied to derive the necessary conditions for fractional-order optimal control. Finally, the theoretical results are validated using two real datasets, and the optimal fractional order is determined through a real-world case. The simulation results show that the smaller the fractional order, the more significant the suppression effect on rumor outbreaks, but the extinction time of the rumor is prolonged accordingly. In addition, the appropriate level of noise intensity can effectively suppress rumor outbreaks, suggesting the presence of stochastic resonance. Furthermore, the implementation of optimal control can effectively curb rumor outbreaks and shorten the life cycle of rumors.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115968"},"PeriodicalIF":4.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupling of non-hydrostatic model with unresolved point-particle model for simulating particle-laden free surface flows","authors":"Yuhang Chen ,&nbsp;Yongping Chen ,&nbsp;Zhenshan Xu ,&nbsp;Pengzhi Lin ,&nbsp;Zhihua Xie","doi":"10.1016/j.apm.2025.115962","DOIUrl":"10.1016/j.apm.2025.115962","url":null,"abstract":"<div><div>Sediment-laden flow is a common phenomenon in nature and the deposition of sediments can make a great difference in landscape formation or marine systems. The complexity of this issue can be further increased with temporal variations in the free surface elevation. This paper aims to present a two-phase flow model that effectively integrates the non-hydrostatic free surface model with the Lagrangian point-particle model. The free surface elevation is conceptualized as a height function and is tracked using a Lagrangian-Eulerian method. This new model is validated by five test cases, showing a good agreement with analytical or experimental results. This demonstrates the model's proficiency in handling sediment-laden flow under various free surface flow conditions, particularly with surface waves. Consequently, the proposed model holds promise for investigating sediment-laden flow issues in coastal regions.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115962"},"PeriodicalIF":4.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient distributed estimation for expectile regression in increasing dimensions","authors":"Xiaoyan Li,&nbsp;Zhimin Zhang","doi":"10.1016/j.apm.2025.115974","DOIUrl":"10.1016/j.apm.2025.115974","url":null,"abstract":"<div><div>In this paper, we introduce an efficient surrogate loss method for large-scale expectile regression in non-randomly distributed scenarios. Specifically, a Poisson subsampling-based distributed asymmetric least squares estimator is proposed. Our theoretical analysis establishes the consistency and asymptotic normality as the dimensionality tends to infinity, demonstrating that the proposed estimator achieves statistical efficiency comparable to that of the global estimator. A practical three-step algorithm is presented, offering an efficient implementation in practical applications. The proposed estimator exhibits two notable advantages: (i) it is communication-efficient, utilising all the data but only requiring the transmission of a small subsample and the local gradient from each local site; and (ii) it can effectively adapt to unevenly distributed data and non-randomly stored data. Within the Newton-Raphson algorithm, the initial value and the Hessian matrix are computed with enhanced robustness using the Poisson subsampling-derived subsample than using one local dataset or uniform subsampling-derived subsample. Both simulation studies and empirical results confirm that the proposed estimator enhanced estimation efficiency relative to existing methods.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"142 ","pages":"Article 115974"},"PeriodicalIF":4.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}