Table 3.
Results of regression analysis on P_x (y in eq.) vs. c (x in eq.) and estimated compression ratio c at P_d for 6 mm-diameter pellet of five Korean domestic wood species

Species	Regression equation	R2	cd at Pd
Populus davidiana	y = 11.321e0.546x	0.999	8.361
Quercus mongolica	y = 14.197e0.577x	0.971	7.838
Robinia pseudoacacia	y = 11.851e0.562x	0.997	8.410
Pinus densiflora	y = 16.181e0.533x	0.979	7.676
Pinus rigida	y = 12.043e0.582x	0.995	7.975