do_quadratic: Quadratic duration-occupancy relation
In QinglongYan/ANSSI: Automated near-stationary state identifier

This function is applied to calculate the minimum acceptable duration given the occupancy based on a polynomial duration-occupancy relation

1	do_quadratic(occ, not, hot, xot, ndr, hdr, xdr)

`occ`	Candidate occupancy, which is the input variable
`not`	Normal-occupancy threshold(*)
`hot`	High-occupancy threshold(*)
`xot`	Extremely high-occupancy threshold(*)
`ndr`	The minimum acceptable duration in normal-occupancy periods(*)
`hdr`	The minimum acceptable duration in high-occupancy periods(*)
`xdr`	The minimum acceptable duration in extremely high-occupancy periods(*)