城市区域性人口承载力动态综合测度

对马尔萨斯人口增长模型进行研究,设计人口承载力发展路径和基于增长模型的隶属函数,从概率角度构建人口承载力动态综合测度模型,同时,以城市区域为研究对象,以经济作为人口承载力主导影响因素,辅之以自然、环境、资源与科技因素,构建人口承载力综合评价指标体系,多角度、多因素分析区域人口承载力,寻找人口承载短板,为人口承载力研究提供新的研究方法和视角.实证研究结论显示,研究区域人口承载力当前处于承载力强阶段,并开始向适度阶段过渡,其内部指标和子系统发展不平衡,人口系统自身发展稳定,经济和环境人口承载力强,资源和科技承载力较弱,随着区域经济的发展,在相当长一段时间内可进入适度人口阶段.     

干预ARIMA模型及其在我国人口总量预测中的实证研究

本文利用干预时序模型方法简明扼要地对我国建国以来的人口发展趋势建立了动态模型,并预测了未来几年我国人口发展的趋势。结果表明,此模型很好地解释了我国人口发展的动态结构,为促进我国人口政策的调整与扩展提供了很好的参考依据。     

分工演进、金融发展与经济增长实证研究—基于浙湘1992-2006年数据和PLSR静动态通径模型

根据浙湘1992-2006年的数据,反复设定静态与动态偏最小二乘通径分析模型进行实证估计和检验。分析结果表明多潜变量静态通径模型通径系数估计值绝大多数是统计显著的;双潜变量动态通径模型的即期通径系数估计值和滞后通径系数估计值是统计显著的,显示了潜变量之间的静态与动态作用定量关系。这些分析结果为深入探索中国省区分工演进、金融发展与经济增长的机制提供了经验证据,也为深入探索中国多区域尺度金融发展与经济增长的关系提供了新的方法。     

农村人口结构变化对经济增长影响的实证分析

以辽宁省大连市农村地区为研究样本,通过构建农村人口结构变化对经济增长影响的"动态效应"模型和"静态效应"模型,分析了农村人口结构变化对农村经济增长的影响.研究结果表明,人力资本是农村经济增长的重要源泉,在既定的农村劳动力从业人口中,男性劳动力人口数量的适度增加能够在一定程度上提高农村经济的增长水平;农村转移劳动力的就业方向对农村经济增长有重要影响;农村储蓄率的增加对于农村经济增长和一系列公共服务的提供具有显著影响效应.     

中国旅游产业发展的人口因素分析

三十年来,中国的人口总量得到了有效的控制,人口结构出现了许多新的特点,人口数量和结构的这些变化对中国旅游业发生了怎样的影响呢,对此,本研究做了些初步的探讨.基于1995年-2014年间的我国旅游产业和人口的两组指标数据,采用典型相关分析法,进行了中国人口因素对旅游产业的影响分析.在典型相关变量的解释方面,充分利用了典型载荷和交叉典型载荷,对旅游产业和人口这两个经济现象的整体之间以及整体与个别之间的相关信息进行了全面挖掘和解读.结果显示,劳动力在产业间的转移、人口规模和结构的变化均与旅游业的发展高度相关,它们之间的变化趋势表现为相互之间的正影响关系,中国老龄化进程与旅游业的发展高度正相关.     

动态死亡率模型的研究进展

死亡率的预测是人口预测的基础.近年来,死亡率建模方法不断取得新的进展,从最早的静态死亡率模型开始,死亡率模型不断发展为包括时间项的动态预测模型,如Lee-Carter族模型、CBD族模型等.本文对死亡率预测模型的相关文献进行了回顾和梳理.随着动态模型的发展,一些学者从死亡率改善水平入手,发展出一系列死亡率改善模型.另外,随着死亡率研究的深入,多人口死亡率的建模引起了研究者的重视,多人口预测模型迅速发展和完善.随着死亡率模型的研究方法不断丰富和创新,新兴统计学方法(如机器学习等)已经在死亡率建模中有所应用,拟合和预测准确度不断提升.除了经典的建模方法的扩展外,例如小区域人口或数据缺失的人口、高龄人口、相关人口等死亡率建模问题仍值得研究.     

具有内生人口规模的城市经济增长模型

本文研究了城市经济增长与人口规模的相互关系.通过引入含消费与舒适度的双变量效用函数,提出了城市居民效用最大化问题.利用动态优化与动力系统,得出描述模型的二维动力系统,具有唯一双曲型平衡点和优化问题存在唯一最优增长路径.因而,对城市经济增长存在最优的人口规模.     

中国人口增长与粮食生产的协整研究

本文以1978-2004年为样本数据,对中国人口和粮食产量进行了单位根检验、协整检验和Granger因果关系检验.结果表明,样本期内人口因素不是粮食生产的Geanger原因,人口增长和粮食生产发展并不协调.通过建立中国粮食生产模型,预测了2006-2010年的人口增长与粮食生产趋势,提出了实现中国人口增长与粮食生产和谐发展的几点建议.     

人口结构和经济增长对碳排放的影响分析

利用中国30个省级行政单位(暂不包括港澳台地区,下同)2005~2014年的数据,采用动态面板模型,研究人口结构、经济增长对碳排放的影响.研究结果表明,从全国范围来看,人均GDP、劳动年龄人口比率、城市化率、第二产业就业率及对外开放度均对碳排放有显著正向影响,而平均家庭规模会减少碳排放量;从区域来看,人均GDP、劳动年龄人口比率对碳排放产生显著正向影响,其他因素对碳排放的影响程度及方向有较大差异.     

青海省重点开发区人口资源环境承载力评价研究

选择青海省重点开发区的26个县、市(区)为研究对象,利用全局主成分分析(GPCA)、聚类分析等方法,根据人口经济活动支撑力、资源供给支持力和生态环境承载力及综合人口资源环境承载力等四个方面对这些地区1999-2012年人口资源环境承载力状况进行了定量、动态评价和分析.指数化的评价结果表明,青海省重点开发区人口资源环境承载力逐年提高,综合人口资源环境承载力指数均值从1999年的-0.29365上升到2012年的0.336723.     

基于预测模型的我国人口结构问题研究

针对我国人口结构问题,在对相关人口数据进行收集、计算、整理并分析的基础上,通过建立总人口预测模型对2010-2014年人口数量预测,与原始人口数据对比进行模型验证和改进,运用此模型对之后6年人口数量预测,应用队列要素预测法找出相应政策对人口结构变化的影响,通过建立适婚群体预测模型对中国适婚入口中的男女数量定量分析,进而对我国人口结构问题进行整体概括总结.     

关于灰色绝对关联计算模型的探讨

本文通过对现有灰色关联度计算模型的分析,指出了现有灰色关联度计算模型的缺陷,针对不同类型问题构造了不同灰色关联度计算模型,并将其应用于解决实际问题,取得较好的效果．     

基于灰色马尔可夫链模型的人口预测

将灰色预测模型和马尔可夫链预测相结合,将其应用到人口预测中,并依据南京市历年总人口数据进行计算,可以比较准确地预测2008年的户籍人口数,验证了其有效性;同时由模型可以预测2010年,2011年南京户籍人口数以做参考用,灰色马尔可夫链可视为人口预测的可行且有效的方法。     

Reviews on the Research of Dynamic Mortality Models

Mortality forecasting is the basis of population forecasting. In recent years, new progress has been made in mortality models. From the earliest static mortality models, mortality models have been developed into dynamic forecasting models including time terms, such as Lee-Carter model family, CBD model family and so on. This paper reviews and sorts out relevant literature on mortality forecasting models. With the development of dynamic models, some scholars have developed a series of mortality improvement models based on the level of mortality improvement. In addition, with the progress of mortality research, multi-population mortality modeling attracted the attention of researchers, and the multi-population forecasting models have been constantly developed and improved, which play an important role in the mortality forecasting. With the continuous enrichment and innovation of mortality model research methods, new statistical methods (such as machine learning) have been applied in mortality modeling, and the accuracy of fitting and prediction has been improved. In addition to the extension of classical modeling methods, issues such as small-area population or missing data of the population, the elderly population, the related population mortality modeling are still worth studying.     

Discrete-time host–parasitoid models with Allee effects: Density dependence versus parasitism

We present two general discrete-time host–parasitoid models with Allee effects on the host. In the first model, it is assumed that parasitism occurs prior to density dependence, while in the second model we assume that density dependence operates first followed by parasitism. It is shown that both models have similar asymptotic behaviour. The parasitoid population will definitely go extinct if the maximal growth rate of the host population is less than or equal to one, independent of whether density dependence or parasitism occurs first. The fate of the population is initial condition dependent if this maximal growth rate exceeds one. In particular, there exists a host population threshold, the Allee threshold, below which the host population goes extinct and so does the parasitoid. This threshold is the same for both models. Numerical examples with different functions are simulated to illustrate our analytical results.     

灰色预测法的进一步推广及应用

把原始时间序列进行多次累加,产生多个新序列,研究它们之间的关系,建立多元线性(或非线性)回归模型.给定显著性水平α,对回归方程进行显著性检验,在置信度1-α下,利用微分,差分关系建立相应的高阶微分方程,从而实现对原序列的预测或控制.该方法进一步推广了灰色预测法,为时间序列建模提供了一个新手段,一些著名的微分方程模型成为这一方法的特例,最后,用该方法对中国1979年至2008年的GDP序列建立微分方程模型并进行预测.     

USING RESERVES TO PROTECT FISH AND WILDLIFE SIMPLIFIED MODELING APPROACHES

ABSTRACT. This paper investigates theoretically to what extent a nature reserve may protect a uniformly distributed population of fish or wildlife against negative effects of harvesting. Two objectives of this protection are considered: avoidance of population extinction and maintenance of population, at or above a given precautionary population level. The pre‐reserve population is assumed to follow the logistic growth law and two models for post‐reserve population dynamics are formulated and discussed. For Model A by assumption the logistic growth law with a common carrying capacity is valid also for the post‐reserve population growth. In Model B, it is assumed that each sub‐population has its own carrying capacity proportionate to its distribution area. For both models, migration from the high‐density area to the low‐density area is proportional to the density difference. For both models there are two possible outcomes, either a unique globally stable equilibrium, or extinction. The latter may occur when the exploitation effort is above a threshold that is derived explicitly for both models. However, when the migration rate is less than the growth rate both models imply that the reserve can be chosen so that extinction cannot occur. For the opposite case, when migration is large compared to natural growth, a reserve as the only management tool cannot assure survival of the population, but the specific way it increases critical effort is discussed.     

Attenuant cycles in periodically forced discrete-time age-structured population models

In discrete-time age-structured population models, a periodic environment is not always deleterious. We show that it is possible to have the average of the age class populations over an attracting cycle (in a periodic environment) not less than the average of the carrying capacities (in a corresponding constant environment). In our age-structured model, a periodic environment does not increase the average total biomass (no resonance). However, a periodic environment is disadvantageous for a population whenever there is no synchrony between the number of age classes and the period of the environment. As in periodically forced models without age-structure, we show that periodically forced age-structured population models support multiple attractors with complicated structures.     

Basic Reproduction Number in a Growing Population

The basic reproduction number of a fast disease epidemic on a slowly growing network may increase to a maximum then decrease to its equi- librium value while the population increases, which is not displayed by classical homogeneous mixing disease models. In this paper, we show that, by properly keeping track of the dynamics of the per capita contact rate in the population due to population dynamics, classical homogeneous mixing models show simi- lar non-monotonic dynamics in the basic reproduction number. This suggests that modeling the dynamics of the contact rate in classical disease models with population dynamics may be important to study disease dynamics in growing populations.     

A mathematical model of infectious diseases

In the formulation of models for the spread of communicable diseases which include removal and population dynamics, it is necessary to distinguish between removal through recovery with immunity and removal by death due to disease. This distinction must be made because of the difference in the effect on the population dynamics of the different kinds of removal and because there are significant differences in the behavior of the models. We have formulated a class of models which allow recovery with immunity for a fraction of the infective and permanent removal by death from disease for the remainder. Earlier models of this type have postulated an increased death rate for infective, but such models are restricted to exponentially distributed-infective periods. Because of the differences in behavior between models with recovery and models with permanent removal do not arise when the infective period is exponentially distributed, we have chosen to formulate a different type of model which is sufficiently general to admit qualitative differences.