Yu, Jingyuan; Guo, Baozhu; Zhu, Guangtian Approximate controllability of population control system and time-optimal control. (English) Zbl 0696.93010 Kexue Tongbao, Sci. Bull. 33, No. 3, 177-181 (1988). We study the controllability of a non-stationary population control system of the form \[ \frac{\partial p(r,t)}{\partial t}+\frac{\partial p(r,t)}{\partial r}=-\mu (r,t)p(r,t)+f(r,t),\quad 0<r<r_ m,\quad t>0, \]\[ p(r,0)=p_ 0(r),\quad 0\leq r\leq r_ m, \]\[ p(0,t)=\beta (t)\int^{r_ 2}_{r_ 1}k(r,t)h(r,t)p(r,t)dr,\quad t\geq 0, \] The problem of time optimal control is discussed. Cited in 1 Document MSC: 93B05 Controllability 49J20 Existence theories for optimal control problems involving partial differential equations 92D25 Population dynamics (general) 93C20 Control/observation systems governed by partial differential equations Keywords:population control system PDFBibTeX XMLCite \textit{J. Yu} et al., Kexue Tongbao, Sci. Bull. 33, No. 3, 177--181 (1988; Zbl 0696.93010)