建设工程项目管理办法.doc

摘要
中国是世界上人口最多的发展中国家,人口问题始终是制约中国发展的关键因素之一。用数学建模的方法对人口发展的过程进行描述分析和预测, 进而研究控制人口增长和人口结构等问题, 早已引起社会各有关方面的极大关注。
本文根据已有的数据资料,结合中国人口增长特点,将市、镇、乡不同性别的人口按不同的年龄段分别讨论,并结合人口迁移的特点,建立了带有迁移项的改进的Leslie矩阵模型,对于中长期人口发展趋势的预测,进一步建立相应的Logistic城镇化模型和中长期人口模型。本文利用Matlab及Excel等软件对我国短期、中长期人口进行预测得出市、镇、乡的各个年龄段男女的人口数。并对中国人口出现的老龄化、男女性别比例等问题进行具体分析,得到比较理想的预测结果。分析表明:中国人口总体趋势保持持续增长,零增长将在大约15年和40年后各有一次,,在2025年以后人口总数平稳过渡,,然后趋于平稳;男女性别比将持续升高,若不加任何因素制约,今后的发展趋势令人堪忧;老龄人口在全国人口中所占百分比在2035年之前持续增加,%,之后持续降低。
关键词:Leslie模型;人口迁移;Matlab;Excel;老龄化
PREDICTION MODEL OF CHINA’S POPULATION GROWTH
ABSTRACT
China is a developing country with the most population in the word. The problem of population is one of the key factors to limit the development of China from beginning to end. Using mathematical models to analysis and describe the process of the population’s growth and control the growth and structures of population has already long ago caused extensive concern of the society.
Based on Chinese demographic data from 2001to 2005 as well as the character of China's population growth, we divided the population of cities, towns and villages into different gender at different ages and established the modified Leslies matrix iteration population projection model, which considered the migration term. Especially for medium-term and long-term research we introduced Logistic model of urbanization problem and created the population model of medium and long term.
In this paper, we used puter softwares such as Excel and Matlab to solve these models and obtained men and women population in cities, towns, villages in various ages. And we analyzed such issues as the trend of Chinese population in future, Chinese population aging, sex ratio and so on. Then we obtained the ideal prediction results as follows.
The results shows that the total population will maintain increasing tend continuously in the following 50 years. There will be two zero-growth period and one ing i