RUNGE-KUTTA is the blackbox optimization problem described in the DFO/BBO book of Audet and Hare.
The problem was originaly described in the followind reference. Please cite it if you use RUNGE-KUTTA:
@article{audet_rk_2018,
Author = {C. Audet},
Title = {{Tuning Runge-Kutta parameters on a family of ordinary differential equations}},
Journal = {International Journal of Mathematical Modelling and Numerical Optimisation},
Volume = {8},
Number = {3},
Pages = {277--286},
Year = {2018},
Doi = {10.1504/IJMMNO.2018.088992},
Url = {http://dx.doi.org/10.1504/IJMMNO.2018.088992}
}