A computer-implemented method and system for improving efficiency in a delta compression process in a data storage system selects a data chunk to delta compress and selects a set of candidate data chunks using a first selection mechanism. Electronic documents are classified and published via an ontological description consisting of at least one vector, each vector comprising at least one feature-value pair. The dielectric applicator comprises two sections, an upper section 4 provided with the load chamber and a lower section 6 for impedance matching between the coupling device and upper section. The system further includes a beamformer that is in communication with the first processing module and an adaptive beamformer that is in communication with the second processing module and the beamformer. The computing system is then booted from the alternate volume group on the second storage device.