Symbolic Techniques for the Selection of Test Frequencies in Analog Fault Diagnosis

In this work symbolic methods are used for implementing a procedure for the selection of test frequencies in multifrequency parametric fault diagnosis of analog linear circuits. The proposed approach is based on the evaluation of the condition number and the norm of a sensitivity matrix of the circuit under test. This matrix is determined by exploiting the testability and ambiguity group concepts. A Test Error Index (T.E.I.) is obtained which permits to select the set of frequencies which better leads to locate parametric faults in analog linear circuits. A program implementing the proposed procedure has been realized by using symbolic techniques. Examples of application are also included.     

Moral reasoning and automatic risk reaction during driving

Cognition, Technology & Work - Recent advances in autonomous vehicles promise to revolutionize the transportation system. This perspective has led to new research on a number of open questions,...     

Tunable morphology of aluminum oxide whiskers grown by hydrothermal method

Hydrothermal method was used to grow α-Al₂O₃ whiskers by using hydrated aluminum sulfate, urea and poly ethylene glycol as precursors. X-ray diffraction (XRD), selected area electron diffraction (SAED), and high resolution transmission electron microscope (HRTEM) were used to characterize morphology of the whiskers. By increasing the pH of the solution (by adding extra NaOH), by adjusting calcination times and atmospheres it was possible to tune the whiskers morphology and their aspect ratio. Aspect ratio as high as 25 was obtained after hydrothermal treatment of a solution having pH 3 followed by calcination in Ar or N₂ atmosphere at 1200?°C for 6 h.