Deriving algebraic Petri net specifications from structured analysis—a case study
Abstract Algebraic Petri nets have been developed as a suitable formal method for concurrent and distributed systems in recent years. However, applications of algebraic Petri nets to non-trivial real-world systems are scarce. In this paper, we present an algebraic Petri net specification of an automatic teller machine system. The algebraic Petri net specification is systematically derived from an informal specification written in structured analysis methods by using a methodology developed in our earlier work. Our results in this paper: (1) demonstrated a feasible approach to construct algebraic Petri net specifications; (2) provided sufficient details for potential users to understand and use algebraic Petri nets through a non-trivial real-world system; and (3) established a baseline for meaningful comparisons of different formal methods.
We report preliminary results on the transfer of the ammonia MBE technology of AlN/AlGaN/GaN/AlGaN heterostructures to silicon substrates. Optimization of the growth conditions allowed the number of macroscopic cracks in the epilayers to be reduced and ensured the growth of heterostructures with two-dimensional electron gas, which are suitable for the creation of field-effect transistors. The saturation current of prototype devices based on the heterostructures grown on silicon substrates are comparable with the analogous parameter of devices grown on sapphire and exhibits no decrease related to thermal scattering at high bias voltages.