European Journal of Applied Mathematics最新文献_第4页

Recurrent and chaotic outbreaks in SIR model SIR 模型中的反复和混乱爆发

IF 1.9 4区数学

European Journal of Applied Mathematics Pub Date : 2024-01-18 DOI: 10.1017/s0956792523000360

Chunyi Gai, Theodore Kolokolnikov, Jan Schrader, Vedant Sharma

引用次数: 0

Absolute concentration robustness and multistationarity in reaction networks: Conditions for coexistence 反应网络中的绝对浓度稳健性和多稳定性：共存的条件

IF 1.9 4区数学

European Journal of Applied Mathematics Pub Date : 2024-01-02 DOI: 10.1017/s0956792523000335

Nidhi Kaihnsa, Tung Nguyen, Anne Shiu

引用次数: 0

Variational inequalities arising from credit rating migration with buffer zone 有缓冲区的信用评级迁移所产生的变量不等式

IF 1.9 4区数学

European Journal of Applied Mathematics Pub Date : 2023-12-14 DOI: 10.1017/s095679252300030x

Xinfu Chen, Jin Liang

引用次数: 0

Analysis and numerical simulations of travelling waves due to plant–soil negative feedback 植物-土壤负反馈引起的行波分析与数值模拟

IF 1.9 4区数学

European Journal of Applied Mathematics Pub Date : 2023-12-07 DOI: 10.1017/s0956792523000323

Annalisa Iuorio, Nicole Salvatori, Gerardo Toraldo, Francesco Giannino

{"title":"Analysis and numerical simulations of travelling waves due to plant–soil negative feedback","authors":"Annalisa Iuorio, Nicole Salvatori, Gerardo Toraldo, Francesco Giannino","doi":"10.1017/s0956792523000323","DOIUrl":"https://doi.org/10.1017/s0956792523000323","url":null,"abstract":"In this work, we carry out an analytical and numerical investigation of travelling waves representing arced vegetation patterns on sloped terrains. These patterns are reported to appear also in ecosystems which are not water deprived; therefore, we study the hypothesis that their appearance is due to plant–soil negative feedback, namely due to biomass-(auto)toxicity interactions. To this aim, we introduce a reaction-diffusion-advection model describing the dynamics of vegetation biomass and toxicity which includes the effect of sloped terrains on the spatial distribution of these variables. Our analytical investigation shows the absence of Turing patterns, whereas travelling waves (moving uphill in the slope direction) emerge. Investigating the corresponding dispersion relation, we provide an analytic expression for the asymptotic speed of the wave. Numerical simulations not only just confirm this analytical quantity but also reveal the impact of toxicity on the structure of the emerging travelling pattern. Our analysis represents a further step in understanding the mechanisms behind relevant plants‘ spatial distributions observed in real life. In particular, since vegetation patterns (both stationary and transient) are known to play a crucial role in determining the underlying ecosystems’ resilience, the framework presented here allows us to better understand the emergence of such structures to a larger variety of ecological scenarios and hence improve the relative strategies to ensure the ecosystems’ resilience.","PeriodicalId":51046,"journal":{"name":"European Journal of Applied Mathematics","volume":"3 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138579176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Propagation dynamics of a mutualistic model of mistletoes and birds with nonlocal dispersal 具有非局部扩散的槲寄生与鸟类共生模式的繁殖动力学

IF 1.9 4区数学

European Journal of Applied Mathematics Pub Date : 2023-12-04 DOI: 10.1017/s0956792523000311

Juan He, Guo-Bao Zhang, Ting Liu

{"title":"Propagation dynamics of a mutualistic model of mistletoes and birds with nonlocal dispersal","authors":"Juan He, Guo-Bao Zhang, Ting Liu","doi":"10.1017/s0956792523000311","DOIUrl":"https://doi.org/10.1017/s0956792523000311","url":null,"abstract":"This paper is devoted to the study of the propagation dynamics of a mutualistic model of mistletoes and birds with nonlocal dispersal. By applying the theory of asymptotic speeds of spread and travelling waves for monotone semiflows, we establish the existence of the asymptotic spreading speed $c^*$ , the existence of travelling wavefronts with the wave speed $cge c^*$ and the nonexistence of travelling wavefronts with $clt c^*$ . It turns out that the spreading speed coincides with the minimal wave speed of travelling wavefronts. Moreover, some lower and upper bound estimates of the spreading speed $c^*$ are provided.","PeriodicalId":51046,"journal":{"name":"European Journal of Applied Mathematics","volume":"35 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138539695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Propagation dynamics of a mutualistic model of mistletoes and birds with nonlocal dispersal 具有非局部扩散的槲寄生与鸟类共生模式的繁殖动力学

IF 1.9 4区数学

European Journal of Applied Mathematics Pub Date : 2023-12-04 DOI: 10.1017/s0956792523000311

Juan He, Guo-Bao Zhang, Ting Liu

{"title":"Propagation dynamics of a mutualistic model of mistletoes and birds with nonlocal dispersal","authors":"Juan He, Guo-Bao Zhang, Ting Liu","doi":"10.1017/s0956792523000311","DOIUrl":"https://doi.org/10.1017/s0956792523000311","url":null,"abstract":"This paper is devoted to the study of the propagation dynamics of a mutualistic model of mistletoes and birds with nonlocal dispersal. By applying the theory of asymptotic speeds of spread and travelling waves for monotone semiflows, we establish the existence of the asymptotic spreading speed $c^*$ , the existence of travelling wavefronts with the wave speed $cge c^*$ and the nonexistence of travelling wavefronts with $clt c^*$ . It turns out that the spreading speed coincides with the minimal wave speed of travelling wavefronts. Moreover, some lower and upper bound estimates of the spreading speed $c^*$ are provided.","PeriodicalId":51046,"journal":{"name":"European Journal of Applied Mathematics","volume":"35 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138539699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Leveraging memory effects and gradient information in consensus-based optimisation: On global convergence in mean-field law 在基于共识的优化中利用记忆效应和梯度信息:关于平均场律的全局收敛

4区数学

European Journal of Applied Mathematics Pub Date : 2023-10-20 DOI: 10.1017/s0956792523000293

Konstantin Riedl

{"title":"Leveraging memory effects and gradient information in consensus-based optimisation: On global convergence in mean-field law","authors":"Konstantin Riedl","doi":"10.1017/s0956792523000293","DOIUrl":"https://doi.org/10.1017/s0956792523000293","url":null,"abstract":"Abstract In this paper, we study consensus-based optimisation (CBO), a versatile, flexible and customisable optimisation method suitable for performing nonconvex and nonsmooth global optimisations in high dimensions. CBO is a multi-particle metaheuristic, which is effective in various applications and at the same time amenable to theoretical analysis thanks to its minimalistic design. The underlying dynamics, however, is flexible enough to incorporate different mechanisms widely used in evolutionary computation and machine learning, as we show by analysing a variant of CBO which makes use of memory effects and gradient information. We rigorously prove that this dynamics converges to a global minimiser of the objective function in mean-field law for a vast class of functions under minimal assumptions on the initialisation of the method. The proof in particular reveals how to leverage further, in some applications advantageous, forces in the dynamics without loosing provable global convergence. To demonstrate the benefit of the herein investigated memory effects and gradient information in certain applications, we present numerical evidence for the superiority of this CBO variant in applications such as machine learning and compressed sensing, which en passant widen the scope of applications of CBO.","PeriodicalId":51046,"journal":{"name":"European Journal of Applied Mathematics","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135617449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of concurrency on epidemic spreading in Markovian temporal networks 马尔可夫时间网络中并发性对流行病传播的影响

4区数学

European Journal of Applied Mathematics Pub Date : 2023-10-18 DOI: 10.1017/s095679252300027x

Ruodan Liu, Masaki Ogura, Elohim Fonseca Dos Reis, Naoki Masuda

{"title":"Effects of concurrency on epidemic spreading in Markovian temporal networks","authors":"Ruodan Liu, Masaki Ogura, Elohim Fonseca Dos Reis, Naoki Masuda","doi":"10.1017/s095679252300027x","DOIUrl":"https://doi.org/10.1017/s095679252300027x","url":null,"abstract":"Abstract The concurrency of edges, quantified by the number of edges that share a common node at a given time point, may be an important determinant of epidemic processes in temporal networks. We propose theoretically tractable Markovian temporal network models in which each edge flips between the active and inactive states in continuous time. The different models have different amounts of concurrency while we can tune the models to share the same statistics of edge activation and deactivation (and hence the fraction of time for which each edge is active) and the structure of the aggregate (i.e., static) network. We analytically calculate the amount of concurrency of edges sharing a node for each model. We then numerically study effects of concurrency on epidemic spreading in the stochastic susceptible-infectious-susceptible and susceptible-infectious-recovered dynamics on the proposed temporal network models. We find that the concurrency enhances epidemic spreading near the epidemic threshold, while this effect is small in many cases. Furthermore, when the infection rate is substantially larger than the epidemic threshold, the concurrency suppresses epidemic spreading in a majority of cases. In sum, our numerical simulations suggest that the impact of concurrency on enhancing epidemic spreading within our model is consistently present near the epidemic threshold but modest. The proposed temporal network models are expected to be useful for investigating effects of concurrency on various collective dynamics on networks including both infectious and other dynamics.","PeriodicalId":51046,"journal":{"name":"European Journal of Applied Mathematics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135885139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sharp asymptotic profile of the solution to a West Nile virus model with free boundary 具有自由边界的西尼罗病毒模型解的尖锐渐近轮廓

4区数学

European Journal of Applied Mathematics Pub Date : 2023-10-13 DOI: 10.1017/s0956792523000281

Zhiguo Wang, Hua Nie, Yihong Du

{"title":"Sharp asymptotic profile of the solution to a West Nile virus model with free boundary","authors":"Zhiguo Wang, Hua Nie, Yihong Du","doi":"10.1017/s0956792523000281","DOIUrl":"https://doi.org/10.1017/s0956792523000281","url":null,"abstract":"Abstract We consider the long-time behaviour of a West Nile virus (WNv) model consisting of a reaction–diffusion system with free boundaries. Such a model describes the spreading of WNv with the free boundary representing the expanding front of the infected region, which is a time-dependent interval $[g(t), h(t)]$ in the model (Lin and Zhu, Spatial spreading model and dynamics of West Nile virus in birds and mosquitoes with free boundary. J. Math. Biol. 75, 1381–1409, 2017). The asymptotic spreading speed of the front has been determined in Wang et al. (Spreading speed for a West Nile virus model with free boundary. J. Math. Biol. 79, 433–466, 2019) by making use of the associated semi-wave solution, namely $lim _{tto infty } h(t)/t=lim _{tto infty }[!-g(t)/t]=c_nu$ , with $c_nu$ the speed of the semi-wave solution. In this paper, by employing new techniques, we significantly improve the estimate in Wang et al. (Spreading speed for a West Nile virus model with free boundary. J. Math. Biol. 79, 433–466, 2019): we show that $h(t)-c_nu t$ and $g(t)+c_nu t$ converge to some constants as $tto infty$ , and the solution of the model converges to the semi-wave solution. The results also apply to a wide class of analogous Ross–MacDonold epidemic models.","PeriodicalId":51046,"journal":{"name":"European Journal of Applied Mathematics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135853170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Generalised solution to a 2D parabolic-parabolic chemotaxis system for urban crime: Global existence and large-time behaviour 城市犯罪的二维抛物-抛物趋化系统的一般解:全局存在性和大时间行为

4区数学

European Journal of Applied Mathematics Pub Date : 2023-09-25 DOI: 10.1017/s0956792523000268

Bin Li, Li Xie

引用次数: 0