STATISTICAL ANALYSIS
All data were subjected to an analysis of variance using
SAS (1999). Data from different types of production rooms
and measurement months were pooled and analyzed as
repeated measurements using the mixed model (PROC
MIXED). The different types of rooms were treated as the
main factor, and measured months were treated as the
subfactor. Due to the interaction of the types of rooms with
the measurement months, the data for each type of room were
analyzed separately using the general linear models (PROC
GLM). Correlation and regression analysis among measured
variables were conducted using the PROC CORR and REGprocedures of SAS. Both treatment effects, correlation coef−
ficients, and regression coefficients were considered significant
at P < 0.05. All data used in the statistical analyses used
normal scale, i.e., odor concentration in OU/m3 and odor
emission rate in OU m−2 s−1 or OU s−1. However, when the statistical
analysis results regarding mean odor concentrations
and emission rates of each type of room or of the same room
over the year were presented, geometric means were used
(CEN, 1999).