Mathematical Population Studies最新文献_第2页

Daily Covid-19 infected population densities in Italian provinces follow Taylor’s law 意大利各省每日新冠肺炎感染人口密度遵循泰勒定律

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2023-01-05 DOI: 10.1080/08898480.2022.2155415

F. Benassi, A. Naccarato, Meng Xu

{"title":"Daily Covid-19 infected population densities in Italian provinces follow Taylor’s law","authors":"F. Benassi, A. Naccarato, Meng Xu","doi":"10.1080/08898480.2022.2155415","DOIUrl":"https://doi.org/10.1080/08898480.2022.2155415","url":null,"abstract":"ABSTRACT Taylor’s law states that the spatial variance of the population density varies as the power function of the mean population density. This law is tested on daily Covid-19 infection density for five periods between February 25, 2020 and March 15, 2021. The Italian provinces are grouped by geography into three ensembles. A simultaneous-equation model accounts for correlations between the ensembles, between Italian provinces within each ensemble, and for temporal autocorrelations. The selected periods show ensembles with all Taylor’s law slopes below 2 (reflecting State interventions at the national level), or all above 2 (reflecting interventions at the local level), or some ensembles above while others were below. Slope of Taylor’s law and average density trend indicate whether the infection density is highly concentrated in a few provinces (when the slope is greater than 2 with increasing density, and when the slope is less than 2 with decreasing density) or spread evenly among all provinces in an ensemble (when the slope is greater than 2 with decreasing density, and when the slope is less than 2 with increasing density), which allows the government and epidemiologists to design disease control policies for targeted provinces and ensembles in Italy.","PeriodicalId":49859,"journal":{"name":"Mathematical Population Studies","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47606087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"社会学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Robust estimation of the population mean using quantile regression under systematic sampling 系统抽样下使用分位数回归对总体均值的稳健估计

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-12-05 DOI: 10.1080/08898480.2022.2139072

U. Shahzad, I. Ahmad, N. Al-Noor, M. Hanif, I. Almanjahie

{"title":"Robust estimation of the population mean using quantile regression under systematic sampling","authors":"U. Shahzad, I. Ahmad, N. Al-Noor, M. Hanif, I. Almanjahie","doi":"10.1080/08898480.2022.2139072","DOIUrl":"https://doi.org/10.1080/08898480.2022.2139072","url":null,"abstract":"ABSTRACT Regression ratio mean estimators of a study variable are defined as the coefficients provided by the ordinary least-squares regression of on a given auxiliary variable . They can be improved by using the coefficient of variation and the coefficient of kurtosis of . The influence of outliers on the estimates of the population mean of is neutralized by calculating robust regression coefficients, obtained by the method of either least absolute deviations, Huber-M, Huber-MM, Hampel-M, Tukey-M, or adjusted least squares. These robust coefficients are used to estimate the population mean of under simple random sampling. Extension to systematic sampling—which is a probability sampling in which every element of the population has equal probability of inclusion to be drawn—using the coefficients provided by quantile regression—whose coefficients result from the minimization of the sum of absolute deviations rather than from the square deviations from the regression line—requires ratio estimators of the population mean of . The mean square errors of these estimators are expressed analytically. If the quantile regression coefficient is greater than the ratio of the covariance between the study and the auxiliary variables to the variance of the auxiliary variable minus a function of the mean or the coefficient of variation, skewness, or kurtosis of and , then the proposed robust quantile regression mean estimator of is more efficient than the ratio estimators in the presence of outliers under systematic sampling. The reason is that these estimators only use regression coefficients and not the ratio between the population mean and sample means of the auxiliary variable . The aforementioned condition occurs with the values of the case study. For empirical data of 176 forest strips, the proposed estimate of the volume of timber is over 30% more efficient than the ratio estimates based on quantile regression coefficients.","PeriodicalId":49859,"journal":{"name":"Mathematical Population Studies","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48451618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"社会学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Parameter estimation for the Moore-Bilikam distribution under progressive type-II censoring, with application to failure times Moore-Bilikam分布在渐进II型截尾下的参数估计及其在故障次数中的应用

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-12-05 DOI: 10.1080/08898480.2022.2133850

Mehdi Bazyar, E. Deiri, E. Jamkhaneh

引用次数: 1

Bias and mean square error reduction by changing the shape of the distribution of an auxiliary variable: application to air pollution data in Nan, Thailand 通过改变辅助变量的分布形状来减少偏差和均方误差:应用于泰国南的空气污染数据

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-12-05 DOI: 10.1080/08898480.2022.2145790

Natthapat Thongsak, Nuanpan Lawson

引用次数: 2

Branching random walk in a random time-independent environment 随机时间无关环境下的分支随机漫步

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-12-02 DOI: 10.1080/08898480.2022.2140561

E. Chernousova, O. Hryniv, S. Molchanov

{"title":"Branching random walk in a random time-independent environment","authors":"E. Chernousova, O. Hryniv, S. Molchanov","doi":"10.1080/08898480.2022.2140561","DOIUrl":"https://doi.org/10.1080/08898480.2022.2140561","url":null,"abstract":"ABSTRACT In a lattice population model, particles move randomly from one site to another as independent random walks, split into two offspring, or die. If duplication and mortality rates are equal and take the same value over all lattice sites, the resulting model is a critical branching random walk (characterized by a mean total number of offspring equal to ). There exists an asymptotical statistical equilibrium, also called steady state. In contrast, when duplication and mortality rates take independent random values drawn from a common nondegenerate distribution (so that the difference between duplication and mortality rates has nonzero variance), then the steady state no longer exists. Simultaneously, at all lattice sites, if the difference between duplication and mortality rates takes strictly positive values with strictly positive probability, the total number of particles grows exponentially. The lattice includes large connected sets where the duplication rate exceeds the mortality rate by a positive constant amount, and these connected sets provide the growth of the total population. This is the supercritical regime of branching processes. On the other hand, if the difference between duplication and mortality rates is almost surely negative or null except when it is almost surely zero, then the total number of particles vanishes asymptotically. The steady state can be reached only if the difference between duplication and mortality rates is almost surely zero.","PeriodicalId":49859,"journal":{"name":"Mathematical Population Studies","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44396689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"社会学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Determining the sample size of a post-enumeration survey: The case of China, 2020 抽样后调查样本量的确定:以2020年中国为例

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-06-13 DOI: 10.1080/08898480.2022.2075166

Guihua Hu, Ting Wen, Yuhuan Liu

引用次数: 1

Positive piecewise continuous quasi-periodic solutions to logistic impulsive differential equations logistic脉冲微分方程的正分段连续拟周期解

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-05-09 DOI: 10.1080/08898480.2022.2043067

Liangping Qi, Guowei Zong

{"title":"Positive piecewise continuous quasi-periodic solutions to logistic impulsive differential equations","authors":"Liangping Qi, Guowei Zong","doi":"10.1080/08898480.2022.2043067","DOIUrl":"https://doi.org/10.1080/08898480.2022.2043067","url":null,"abstract":"ABSTRACT To prove the existence of piecewise continuous solutions to a logistic quasi-periodic differential system with impulses (whose coefficients have rationally independent periods), this system is divided into a differential equation and a difference equation. The quasi-periodicity of a function is proved by showing that this function is the uniform limit of a series of trigonometric polynomials with a finite total number of frequencies. The asymptotically stable quasi-periodic positive and piecewise continuous solution is proved to exist and to be unique. Quasi-periodic variation of the environment leads to a quasi-periodic growth of the population size in the sense that the rationally independent frequencies of the system are also frequencies of the quasi-periodic solution. The positive solutions have a repeated behavior similar to that of the quasi-periodic solution for a sufficiently long time due to asymptotical stability. The separation of the continuous-discrete system into a differential equation and a difference equation is a method of proving the existence of a quasi-periodic solution with perturbed coefficients of the impulsive system.","PeriodicalId":49859,"journal":{"name":"Mathematical Population Studies","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44933773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"社会学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multivariate ratio exponential estimators of the population mean under stratified double sampling 分层双抽样下总体均值的多变量比率指数估计

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-05-06 DOI: 10.1080/08898480.2022.2055870

Siraj Muneer, A. Khalil, J. Shabbir

引用次数: 0

Reduced oviposition period promotes blowfly population extinction in Nicholson’s model Nicholson模型中产卵期的缩短促进了蝇类种群的灭绝

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-05-04 DOI: 10.1080/08898480.2022.2051367

I. Elbaz

{"title":"Reduced oviposition period promotes blowfly population extinction in Nicholson’s model","authors":"I. Elbaz","doi":"10.1080/08898480.2022.2051367","DOIUrl":"https://doi.org/10.1080/08898480.2022.2051367","url":null,"abstract":"ABSTRACT Blowflies use open wounds or the accumulation of feces or urine in wool to lay their eggs. The larvae that emerge cause lesions in the host sheep, which can lead to death. They are found in Australia, New Zealand, and the United Kingdom. Nicholson’s model describes the population dynamics of the Australian blowfly (Lucilia Cuprina). It incorporates environmental variation. The extinction of these flies depends on the time to oviposition and the time between generations. The Lyapunov function, which is positive with a negative derivative, provides the condition for the stability of the equilibrium point: the oviposition period must be sufficiently short, because the shorter it is, the more it favors the extinction of the species. The zero solution is the only equilibrium point, synonymous with the extinction of the population. Another species of blowfly, Lucilia Sericata, also attacks sheep in Australia. Both blowflies are ectoparasites of warm-blooded vertebrates, particularly domestic sheep. These two blowflies are related to share same mitochondrial DNA sequences, although the two species are distinct. Presumably to avoid competition between them. the egg-laying time of each species does not occur at the same time of year: L. Sericata prefers warmer months, thus in summer, while L. Cuprina is mainly active in autumn. Laying of eggs in different months allows avoiding competition between these species. This also binds them together. A sufficiently small egg-laying delay then leads to the rapid extinction of both blowfly populations, provided they do not adapt.","PeriodicalId":49859,"journal":{"name":"Mathematical Population Studies","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45320539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"社会学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Poisson regression-ratio estimators of the population mean under double sampling, with application to Covid-19 双重抽样下总体均值的泊松回归比估计，并应用于Covid-19

IF 1.8 3区社会学

Mathematical Population Studies Pub Date : 2022-05-03 DOI: 10.1080/08898480.2022.2051988

H. Koç, Caner Tanış, T. Zaman

引用次数: 5