  As one of the newest members in the field of artificial immune systems (AIS),
the Dendritic Cell Algorithm (DCA) is based on behavioural models of natural
dendritic cells (DCs). Unlike other AIS, the DCA does not rely on training
data, instead domain or expert knowledge is required to predetermine the
mapping between input signals from a particular instance to the three
categories used by the DCA. This data preprocessing phase has received the
criticism of having manually over-?tted the data to the algorithm, which is
undesirable. Therefore, in this paper we have attempted to ascertain if it is
possible to use principal component analysis (PCA) techniques to automatically
categorise input data while still generating useful and accurate classication
results. The integrated system is tested with a biometrics dataset for the
stress recognition of automobile drivers. The experimental results have shown
the application of PCA to the DCA for the purpose of automated data
preprocessing is successful.
