Frontiers in Applied Mathematics and Statistics最新文献_第7页

How many strong earthquakes will there be tomorrow? 明天会有多少次强烈地震?

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-07-05 DOI: 10.3389/fams.2023.1152476

M. Taroni, I. Spassiani, N. Laskin, S. Barani

{"title":"How many strong earthquakes will there be tomorrow?","authors":"M. Taroni, I. Spassiani, N. Laskin, S. Barani","doi":"10.3389/fams.2023.1152476","DOIUrl":"https://doi.org/10.3389/fams.2023.1152476","url":null,"abstract":"In this note, we study the distribution of earthquake numbers in both worldwide and regional catalogs: in the Global Centroid Moment Tensor catalog, from 1980 to 2019 for magnitudes Mw 5. 5+ and 6.5+ in the first case, and in the Italian instrumental catalog from 1960 to 2021 for magnitudes Mw 4.0+ and 5.5+ in the second case. A subset of the global catalog is also used to study the Japanese region. We will focus our attention on short-term time windows of 1, 7, and 30 days, which have been poorly explored in previous studies. We model the earthquake numbers using two discrete probability distributions, i.e., Poisson and Negative Binomial. Using the classical chi-squared statistical test, we found that the Poisson distribution, widely used in seismological studies, is always rejected when tested against observations, while the Negative Binomial distribution cannot be disproved for magnitudes Mw 6.5+ in all time windows of the global catalog. However, if we consider the Japanese or the Italian regions, it cannot be proven that the Negative Binomial distribution performs better than the Poisson distribution using the chi-squared test. When instead we compared the performances of the two distributions using the Akaike Information Criterion, we found that the Negative Binomial distribution always performs better than the Poisson one. The results of this study suggest that the Negative Binomial distribution, largely ignored in seismological studies, should replace the Poisson distribution in modeling the number of earthquakes.","PeriodicalId":36662,"journal":{"name":"Frontiers in Applied Mathematics and Statistics","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42862857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fusing time-varying mosquito data and continuous mosquito population dynamics models 融合时变蚊子数据和连续蚊子种群动态模型

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-30 DOI: 10.3389/fams.2023.1207643

Marina Mancuso, Kaitlyn Martinez, C. Manore, F. Milner, Martha Barnard, H. Godinez

{"title":"Fusing time-varying mosquito data and continuous mosquito population dynamics models","authors":"Marina Mancuso, Kaitlyn Martinez, C. Manore, F. Milner, Martha Barnard, H. Godinez","doi":"10.3389/fams.2023.1207643","DOIUrl":"https://doi.org/10.3389/fams.2023.1207643","url":null,"abstract":"Climate change is arguably one of the most pressing issues affecting the world today and requires the fusion of disparate data streams to accurately model its impacts. Mosquito populations respond to temperature and precipitation in a nonlinear way, making predicting climate impacts on mosquito-borne diseases an ongoing challenge. Data-driven approaches for accurately modeling mosquito populations are needed for predicting mosquito-borne disease risk under climate change scenarios. Many current models for disease transmission are continuous and autonomous, while mosquito data is discrete and varies both within and between seasons. This study uses an optimization framework to fit a non-autonomous logistic model with periodic net growth rate and carrying capacity parameters for 15 years of daily mosquito time-series data from the Greater Toronto Area of Canada. The resulting parameters accurately capture the inter-annual and intra-seasonal variability of mosquito populations within a single geographic region, and a variance-based sensitivity analysis highlights the influence each parameter has on the peak magnitude and timing of the mosquito season. This method can easily extend to other geographic regions and be integrated into a larger disease transmission model. This method addresses the ongoing challenges of data and model fusion by serving as a link between discrete time-series data and continuous differential equations for mosquito-borne epidemiology models.","PeriodicalId":36662,"journal":{"name":"Frontiers in Applied Mathematics and Statistics","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48101139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Linear regression for Poisson count data: a new semi-analytical method with applications to COVID-19 events 泊松计数数据的线性回归：一种应用于新冠肺炎事件的新的半分析方法

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-28 DOI: 10.3389/fams.2023.1112937

M. Bonamente

{"title":"Linear regression for Poisson count data: a new semi-analytical method with applications to COVID-19 events","authors":"M. Bonamente","doi":"10.3389/fams.2023.1112937","DOIUrl":"https://doi.org/10.3389/fams.2023.1112937","url":null,"abstract":"This study presents the application of a new semi-analytical method of linear regression for Poisson count data to COVID-19 events. The regression is based on the maximum-likelihood solution for the best-fit parameters presented in an earlier publication, and this study introduces a simple analytical solution for the covariance matrix that completes the problem of linear regression with Poisson data for one independent variable. The analytical nature of both parameter estimates and their covariance matrix is made possible by a convenient factorization of the linear model proposed by J. Scargle. The method makes use of the asymptotic properties of the Fisher information matrix, whose inverse provides the covariance matrix. The combination of simple analytical methods to obtain both the maximum-likelihood estimates of the parameters and their covariance matrix constitutes a new and convenient method for the linear regression of Poisson-distributed count data, which are of common occurrence across a variety of fields. A comparison between this maximum-likelihood linear regression method for Poisson data and two alternative methods often used for the regression of count data—the ordinary least–square regression and the χ2 regression—is provided with the application of these methods to the analysis of recent COVID-19 count data. The study also discusses the relative advantages and disadvantages among these methods for the linear regression of Poisson count data.","PeriodicalId":36662,"journal":{"name":"Frontiers in Applied Mathematics and Statistics","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48749583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The evolution of resource distribution, slow diffusion, and dispersal strategies in heterogeneous populations 异质种群中资源分布、缓慢扩散和扩散策略的演变

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-26 DOI: 10.3389/fams.2023.1157992

I. Zahan, M. Kamrujjaman, M. Abdul Alim, Mohammad Shahidul Islam, T. Khan

{"title":"The evolution of resource distribution, slow diffusion, and dispersal strategies in heterogeneous populations","authors":"I. Zahan, M. Kamrujjaman, M. Abdul Alim, Mohammad Shahidul Islam, T. Khan","doi":"10.3389/fams.2023.1157992","DOIUrl":"https://doi.org/10.3389/fams.2023.1157992","url":null,"abstract":"Population diffusion in river-ocean ecologies and for wild animals, including birds, mainly depends on the availability of resources and habitats. This study explores the dynamics of the resource-based competition model for two interacting species in order to investigate the spatiotemporal effects in a spatially distributed heterogeneous environment with no-flux boundary conditions. The main focus of this study is on the diffusion strategy, under conditions where the carrying capacity for two competing species is considered to be unequal. The same growth function is associated with both species, but they have different migration coefficients. The stability of global coexistence and quasi-trivial equilibria are also studied under different conditions with respect to resource function and carrying capacity. Furthermore, we investigate the case of competitive exclusion for various linear combinations of resource function and carrying capacity. Additionally, we extend the study to the instance where a higher migration rate negatively impacts population growth in competition. The efficacy of the model in the cases of one- and two-dimensional space is also demonstrated through a numerical study. AMS subject classification 2010 92D25, 35K57, 35K50, 37N25, 53C35.","PeriodicalId":36662,"journal":{"name":"Frontiers in Applied Mathematics and Statistics","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47328598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Corrigendum: Longitudinal modulation of Marangoni wave patterns in thin film heated from below: instabilities and control 勘误:从下面加热的薄膜中马兰戈尼波模式的纵向调制:不稳定性和控制

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-26 DOI: 10.3389/fams.2023.1229581

A. Samoilova, A. Nepomnyashchy

引用次数: 0

Bifurcation of solutions through a contact manifold in bidisperse models 双状态模型中通过接触流形的解的分岔

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-23 DOI: 10.3389/fams.2023.1199011

S. Berres, Pablo Castañeda

{"title":"Bifurcation of solutions through a contact manifold in bidisperse models","authors":"S. Berres, Pablo Castañeda","doi":"10.3389/fams.2023.1199011","DOIUrl":"https://doi.org/10.3389/fams.2023.1199011","url":null,"abstract":"This research focuses on a hyperbolic system that describes bidisperse suspensions, consisting of two types of small particles dispersed in a viscous fluid. The dependence of solutions on the relative position of contact manifolds in the phase space is examined. The wave curve method serves as the basis for the first and second analyses. The former involves the classification of elementary waves that emerge from the origin of the phase space. Analytical solutions to prototypical Riemann problems connecting the origin with any point in the state space are provided. The latter focuses on semi-analytical solutions for Riemann problems connecting any state in the phase space with the maximum packing concentration line, as observed in standard batch sedimentation tests. When the initial condition crosses the first contact manifold, a bifurcation occurs. As the initial condition approaches the second manifold, another structure appears to undergo bifurcation, although it does not represent an actual bifurcation according to the triple shock rule. The study reveals important insights into the behavior of solutions in relation to these contact manifolds. This research sheds light on the existence of emerging quasi-umbilic points within the system, which can potentially lead to new types of bifurcations as crucial elements of the elliptic/hyperbolic boundary in the system of partial differential equations. The implications of these findings and their significance are discussed.","PeriodicalId":36662,"journal":{"name":"Frontiers in Applied Mathematics and Statistics","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43682608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Solving the capacitated vehicle routing problem with time windows via graph convolutional network assisted tree search and quantum-inspired computing 用图卷积网络辅助树搜索和量子启发计算求解带时间窗的有容量车辆路径问题

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-22 DOI: 10.3389/fams.2023.1155356

Jorin Dornemann

{"title":"Solving the capacitated vehicle routing problem with time windows via graph convolutional network assisted tree search and quantum-inspired computing","authors":"Jorin Dornemann","doi":"10.3389/fams.2023.1155356","DOIUrl":"https://doi.org/10.3389/fams.2023.1155356","url":null,"abstract":"Vehicle routing problems are a class of NP-hard combinatorial optimization problems which attract a lot of attention, as they have many practical applications. In recent years there have been new developments solving vehicle routing problems with the help of machine learning, since learning how to automatically solve optimization problems has the potential to provide a big leap in optimization technology. Prior work on solving vehicle routing problems using machine learning has mainly focused on auto-regressive models, which are connected to high computational costs when combined with classical exact search methods as the model has to be evaluated in every search step. This paper proposes a new method for approximately solving the capacitated vehicle routing problem with time windows (CVRPTW) via a supervised deep learning-based approach in a non-autoregressive manner. The model uses a deep neural network to assist finding solutions by providing a probability distribution which is used to guide a tree search, resulting in a machine learning assisted heuristic. The model is built upon a new neural network architecture, called graph convolutional network, which is particularly suited for deep learning tasks. Furthermore, a new formulation for the CVRPTW in form of a quadratic unconstrained binary optimization (QUBO) problem is presented and solved via quantum-inspired computing in cooperation with Fujitsu, where a learned problem reduction based upon the proposed neural network is applied to circumvent limitations concerning the usage of quantum computing for large problem instances. Computational results show that the proposed models perform very well on small and medium sized instances compared to state-of-the-art solution methods in terms of computational costs and solution quality, and outperform commercial solvers for large instances.","PeriodicalId":36662,"journal":{"name":"Frontiers in Applied Mathematics and Statistics","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45696986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structure-preserving model reduction for port-Hamiltonian systems based on separable nonlinear approximation ansatzes 基于可分离非线性逼近分析的端口-哈密顿系统保结构模型约简

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-16 DOI: 10.3389/fams.2023.1160250

P. Schulze

引用次数: 2

Multipatch stochastic epidemic model for the dynamics of a tick-borne disease 蜱传疾病动力学的多匹配随机流行病模型

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-16 DOI: 10.3389/fams.2023.1122410

M. Maliyoni, H. Gaff, K. Govinder, F. Chirove

{"title":"Multipatch stochastic epidemic model for the dynamics of a tick-borne disease","authors":"M. Maliyoni, H. Gaff, K. Govinder, F. Chirove","doi":"10.3389/fams.2023.1122410","DOIUrl":"https://doi.org/10.3389/fams.2023.1122410","url":null,"abstract":"Spatial heterogeneity and migration of hosts and ticks have an impact on the spread, extinction and persistence of tick-borne diseases. In this paper, we investigate the impact of between-patch migration of white-tailed deer and lone star ticks on the dynamics of a tick-borne disease with regard to disease extinction and persistence using a system of Itô stochastic differential equations model. It is shown that the disease-free equilibrium exists and is unique. The general formula for computing the basic reproduction number for all patches is derived. We show that for patches in isolation, the basic reproduction number is equal to the largest patch reproduction number and for connected patches it lies between the minimum and maximum of the patch reproduction numbers. Numerical simulations for a two-patch deterministic and stochastic differential equation models are performed to illustrate the dynamics of the disease for varying migration rates. Our results show that the probability of eliminating or minimizing the disease in both patches is high when there is no migration unlike when it is present. The results imply that the probability of disease extinction can be increased if deer and tick movement are controlled or even prohibited especially when there is an outbreak in one or both patches since movement can introduce a disease in an area that was initially disease-free. Thus, screening of infectives in protected areas such as deer farms, private game parks or reserves, etc. before they migrate to other areas can be one of the intervention strategies for controlling and preventing disease spread.","PeriodicalId":36662,"journal":{"name":"Frontiers in Applied Mathematics and Statistics","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45850023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Invariant forms and control dimensional parameters in complexity quantification 复杂性量化中的不变形式和控制维参数

IF 1.4

Frontiers in Applied Mathematics and Statistics Pub Date : 2023-06-15 DOI: 10.3389/fams.2023.1201043

S. Abarzhi

引用次数: 0