20.500.12556/RUL-132103 Creation of numerical constants in robust gene expression programming The problem of the creation of numerical constants has haunted the Genetic Programming (GP) community for a long time and is still considered one of the principal open research issues. Many problems tackled by GP include finding mathematical formulas, which often contain numerical constants. It is, however, a great challenge for GP to create highly accurate constants as their values are normally continuous, while GP is intrinsically suited for combinatorial optimization. The prevailing attempts to resolve this issue either employ separate real-valued local optimizers or special numeric mutations. While the former yield better accuracy than the latter, they add to implementation complexity and significantly increase computational cost. In this paper, we propose a special numeric crossover operator for use with Robust Gene Expression Programming (RGEP). RGEP is a type of genotype/phenotype evolutionary algorithm closely related to GP, but employing linear chromosomes. Using normalized least squares error as a fitness measure, we show that the proposed operator is significantly better in finding highly accurate solutions than the existing numeric mutation operators on several symbolic regression problems. Another two important advantages of the proposed operator are that it is extremely simple to implement, and it comes at no additional computational cost. The latter is true because the operator is integrated into an existing crossover operator and does not call for an additional cost function evaluation. genetic programming gene expression programming genetic algorithms genotype/phenotype evolutionary algorithms symbolic regression constant creation ephemeral random constants numeric mutation numeric crossover digit-wise crossover genetsko programiranje programiranje z izraženimi geni genetski algoritmi evolucijski algoritmi s preslikavo iz genotipa v fenotip simbolična regresija generiranje konstant prehodne naključne konstante numerična mutacija numerično križanje križanje na nivoju števk true false true Angleški jezik Slovenski jezik Članek v reviji 2021-10-13 07:55:52 2021-10-13 07:55:55 2022-09-12 04:11:03 0000-00-00 00:00:00 2018 0 0 15 str. iss. 10, art. 756 Vol. 20 Oct. 2018 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 004 1099-4300 10.3390/e20100756 12233812 RAZ_Fajfar_Iztok_2018.pdf RAZ_Fajfar_Iztok_2018.pdf 1 CBAB3E87EBEFF8DAAB603CF739907926 b32768352cab5e897fee8c6742aff4f59865ea50b1990c54c59838687f49306f 77bf7e59-2bea-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=149624 https://www.mdpi.com/1099-4300/20/10/756 1 3b1cd901-2bea-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=149623 Fakulteta za elektrotehniko 0 0 0