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Table 1 Generic PSO configuration used when fitting the proposed model to data

From: Calibrating and validating a combined accumulation and mobilisation model for water distribution system discolouration using particle swarm optimisation

Option Choice and notes
Number of particles 25. Smallest square number in the recommended range of 20–50. Must be a square number if using Von Neumann neighbourhoods.
Parameter space box bounds (valid parameter ranges) (No generic values as case specific)
Particle initialisation Uniformly distributed within parameter space box bounds (no justification for using more complicated methods)
Velocity component weights Inertia weight decreases linearly from 0.9 to 0.4 over the total number of optimisation run iterations; nostalgic and societal weights are both 2.1
Problem space boundary handling Restrictive, damping boundary conditions
Maximum particle velocity The absolute size of the region bounded by the box bounds.
Particle neighbourhoods Social rather than geometric; exactly four neighbours per particle (Von Neumann lattice)
Maximum number of iterations 500
Convergence tolerance check Algorithm terminates before the maximum number of iterations if the ‘best’ position in the swarm changes by less than a similarly-dimensioned tolerance threshold over five PSO iterations. Tolerance thresholds not specified as case-specific.