Swart J H
Math Biosci. 1989 Jul;95(1):53-63. doi: 10.1016/0025-5564(89)90051-5.
The classical age-dependent population model is considered, in which mortality depends on total population and fertility is age-dependent. It is shown that in general such systems are not completely controllable with respect to a control variable in the mortality function, but that in certain circumstances a suitable control can be found to hold the population at a specified level.
考虑经典的年龄依赖型人口模型，其中死亡率取决于总人口，而生育率取决于年龄。结果表明，一般而言，此类系统对于死亡率函数中的控制变量并非完全可控，但在某些情况下，可以找到合适的控制方法，使人口维持在特定水平。
