The paper proposed the method for text skew detection based on log-polar transformation. The original image is transformed in the log-polar domain as well as the control ellipse. Theirs cross-correlation established the cost function. The extraction of the cost function maximums gives the text skew value in the left and right region from the centre point of transformation. The method is suitable for the printed text. It is characterized by the accuracy and computational time inexpensiveness.

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The paper discusses some steganographic methods based on the use of the frequency characteristics of the speech signal. In particular, the authors consider a widely used method of steganography spreading and a new method of subband projections. The subband projections steganographic method is based on the application of sub-band analysis using subband matrices. For comparison, we considered steganographic methods used in the work of several different measures of differences. Besides, for comparison, we used the standard error, relative error, the

This paper proposes a method for improving the DC motor velocity estimations and the estimations obtained from the state observer, when the system operates with large moments of inertia. First, the state observer for estimating velocity and DC motor position, is designed. Then, the variable structure controller is formed using estimated position and velocity values. State observer and designed controller are implemented in default system control logic. Dependences between estimated velocities and moments of inertia are established and presented by experimental results. It is noted that velocity time responses of the designed controller are not as expected when the system operates with large moments of inertia on the motor shaft. The feedforward neural network is empirically designed and implemented in control logic with purpose to solve poor velocity estimations and to improve overall system performances. It is experimentally shown that an artificial network improves estimation quality of the observer and overall control of the system for different input signals.