A Bee Evolutionary Algorithm for Multiobjective Vehicle Routing Problem with Simultaneous Pickup and Delivery

Table 1

The meanings of letter symbols in (2).

Letter symbols	Meanings
	Ratio of fuel to air weight
	Engine speed
	Engine friction factor
	Engine exhaust volume
	Acceleration of gravity
	Transmission efficiency
	Engine efficiency
	Truck windward area
	Air resistance coefficient
	Air density
	Travel distance
	Other energy needs
	Rolling resistance coefficient
	Vehicle acceleration
	Mass of vehicle and products
	Vehicle travel speed
	The road slope