abbr. Puerto Rico Economic Development Administration 波多黎各经济开发管理局
preda 用法和例句
In this paper , we obtain constrain qualifications of multi-object optimal programming with the Hadamard directional derivative , extend Maeda and Preda \'s results to some extent .
The simulation results show that the strength of periodic restrictions and the strength and frequency of feeding on prey species have significant influences on the dynamical behaviors of preda - tor - prey systems . When the feeding rate is constant , the system goes from stable states through periodic ( anti - periodic ) fluctuations to extinction as the strength of periodic restriction increases .