Experimental Study of High-Frequency Drill String Vibrations Under Different Conditions -- Flexible Systolic Hardware Architecture for Computing a Custom Lightweight CNN in CT Images Processing for Automated COVID-19 Diagnosis -- Dimensionality Reduction in Handwritten Digit Recognition -- Obtaining Fractal Dimension for Gene Expression Time Series Using an Artificial Neural Network -- Grouping by Mixture of Normals for Breast Cancer in Two Groups, Benign and Malignant.