2.2.3. Crossover

DE has 2 classic crossover strategies, i.e., binomial and exponential. The crossover strategies of SHADE is the same as that of DE/rand/1/bin, i.e., binomial crossover. However, the crossover rate of DE/rand/1/bin is set in advance while the *CRi* of SHADE is generated by the following formula:

$$CR\_i = randn\_i(\mathbf{M}\_{\mathbb{CR},ri}, 0.1) \tag{8}$$

where *randni* () is Gaussian distribution, and *MCR*,*ri* are randomly selected from historical memory *MCR* (index *ri* is a uniformly distributed random value from [1, *H*]). If *CRi* > 1, let *CRi* = 1; if *CRi* < 0, let *CRi* = 0.
