NET Drawing Code 128įor the collected data of the Windows performance objects described in 7, the same data screening procedure as described in Section 82 is performed to eliminate the data variables which have the observations of the same value under all three conditions: the inactive, attack and norm conditions Each of the remaining data variables is analyzed to extract the wavelet feature and discover the wavelet change characteristics of attack and normal use data For the data sample of a given data variable under each condition (inactive, attack and norm) of the collected data, the wavelet transform is performed using each of the ve wavelet forms The statistical toolbox of MATLAB Version 650180913a (R13) is used to perform the wavelet transforms and obtain the wavelet coef cients For the wavelet transform using the Haar and Daubechies wavelets, the k value of 8 is applied to a data sample of 256 data observations Three frequency bands are de ned with the low frequency band containing the three lowest frequencies, the high frequency band containing the three highest frequencies, and the medium frequency band containing the remaining two frequencies For the Paul, DoG and Morelet wavelet transforms applied to each data variable, there are 29 frequencies for 256 data observations These frequencies are considered to fall into three frequency bands: the low frequency band containing the eight lowest frequencies, the high frequency band containing the twelve highest frequencies, and the medium frequency band containing the remaining nine frequencies For each wavelet transform of each variable under each condition (inactive, attack and norm), the Signal Strength (SS) at each frequency band is computed using the wavelet coef cients at that frequency as follows: SS = 1 n