Table 2 Details of the CEC2020 test suite.

From: An improved multi-objective particle swarm optimization algorithm for the design of foundation pit of rail transit upper cover project

Problem number

Function name

Geometry of PS

Geometry of PF

number of global and local optima

TP1

MMF1

Nonlinear

Convex

2

TP2

MMF2

Nonlinear

Convex

2

TP3

MMF4

Nonlinear

Concave

2

TP4

MMF5

Nonlinear

Convex

2

TP5

MMF7

Nonlinear

Convex

2

TP6

MMF8

Nonlinear

Concave

2

TP7

MMF10

Linear

Convex

1

TP8

MMF11

Linear

Convex

1

TP9

MMF12

Linear

Convex

1

TP10

MMF13

Nonlinear

Convex

1

TP11

MMF14

Linear

Concave

2

TP12

MMF15

Linear

Concave

1

TP13

MMF1_e

Nonlinear

Convex

2

TP14

MMF14_a

Nonlinear

Concave

2

TP15

MMF15_a

Nonlinear

Concave

1

TP16

MMF10_l

Linear

Convex

2

TP17

MMF11_l

Linear

Convex

2

TP18

MMF12_l

Linear

Convex

2

TP19

MMF13_l

Nonlinear

Convex

2

TP20

MMF15_l

Linear

Concave

2

TP21

MMF15_a_l

Nonlinear

Concave

2

TP22

MMF16_l1

Linear

Concave

3

TP23

MMF16_l2

Linear

Concave

3

TP24

MMF16_l3

Linear

Concave

4