This work shows the design procedure of fractional-order proportional–integral-derivative (FOPID) controllers for an antenna azimuth position system based on genetic algorithm optimization approach. FOPID controllers are considered as a special type of the classical PID controller in which the derivative and integral elements have orders of fractions between zero and one. Therefore, FOPID controllers comprise two additional variables ( μ and λ ) in comparison with the typical PID controller. The FOPID is designed to control the azimuth angle of the antenna. Genetic algorithm (GA) will be employed to find an optimal value for the five FOPID controller’s gains using different type of fitness function including mean square error (MSE), integral square error (ISE) and integral time square error (ITSE). The achieved results exhibit an excellent steady and transient state performance of system, for instant fast settling and rise times as well as low present of peak overshoot.
The authentication textual passwords are the most widely used technique. However, this type of legacy authentication is vulnerable to various attacks, such as shoulder-surfing attacks. Hence, graphical password authentication is one of these approaches which has been suggested to overcome the issues related to textual passwords. Nevertheless, the hackers have also developed new techniques that can be finally broken the graphical password, for instance, listening to the transmitted information between the client and the server. In this paper, Passnumbers graphical authentication password is proposed. Passnumbers approach involves two new stages, which are first, using the coordinates of a graphical grid cells-based numbers for entering the password. The second stage is represented by deploying a new technique to encrypt the password based on the image pixels. The performance evaluation reveals that the proposed Passnumbers can provide high resistance against several graphical password attacks including shoulder surfing and eavesdropping attacks. Passnumbers is evaluated using several metrics including security and usability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.