نشریه فناوری در مهندسی هوافضا
سال ششم شماره 3 (پیاپی 22، پاییز 1401)

This paper proposes a method based on the artificial intelligence reinforcement Q-learning algorithm and paired comparison technique to solve the problem of health monitoring devices shortage in airlines. In this research, Kish Airline destinations considered as a case study. By considering the importance of continuing air travels during covid-19 pandemic, one of the most effective ways for decreasing the risk of COVID-19 infections in air travels is establishing the health monitoring stations at the airport gates. In view of the enormous number of airports and airlines routes, nationwide coverage of them by health monitoring stations is unimaginable. Therefore, in this paper, artificial intelligence reinforcement Q-learning algorithm functionality in estimating the risk of infecting the COVID-19 virus was considered for the Kish Airline destinations. Furthermore, the optimal policy for the distribution of the health monitoring devices is designed based on the computational model.

In this research, a plasma column with a circular cross section magnetized by a DC-axial magnetic field is investigated as a plasma antenna. The radar cross-section and the scattering pattern of radio waves landing to the antenna are studied. The present plasma antenna, in addition to advantages such as lightness, less thermal noise at satellite frequencies, etc., compared to metal antennas, due to its simple structure and ease of rearrangement by various characteristics such as the intensity of the applied DC magnetic field. The current distribution, gas pressure, and electrical power applied to the gas, which changes the plasma density and its cyclotron frequency, are highly adjustable for new operating frequencies. Such characteristics lead to controllability of the radar cross section and the scattering pattern of the antenna. In this paper, we investigate the effect of plasma frequency and cyclotron frequency of the plasma antenna on the scattering of radio waves with different incident angles and frequencies.

due to the variability and uncertainty of some process parameters under investigation and limited uncertainties and confusions, the controller design faces problems. the controller is performed locally using the information of neighboring agents and the corresponding graph has a spanning tree. fuzzy systems are used as a general approximator and the parameters of the fuzzy system are adjusted in such a way that the tracking error of each agents and the stability of the uniform ultimately bounded of the closed loop system are guaranteed. 1- considering of the nonlinear non-affine of multi-agent system, 2- The unknown dynamics of the agents, 3- The convergence of the tracking error and the formation error to zero, 4- The use of fuzzy systems as a general estimator, are the main advantages of the presented method. Finally, in the simulations performed on the quadrotor, the leader-follower formation for the desired mission is realized and according to the set criteria, the proposed methodology is satisfactory.

Along with the advancement of space science and efforts to extend life beyond the earth, it is important to ‎study the response of microorganisms to microgravity conditions, because the microorganisms will unavoidably ‎be sent to space together with the equipment and passengers. Indeed, exposure to stressful space conditions ‎maybe activates some microorganisms' defense mechanisms which can increase their pathogenicity. Until now, ‎only the responses of a few typical microbes to microgravity have been investigated and the completion of these ‎studies has been delayed due to technical problems and high costs, but it is necessary to study host-microbial ‎interactions, in order to predict these behaviors and take precautionary measures during space flight and even ‎during space station deployment. In the present study, we will review some microbial changes such as growth ‎and metabolic changes and alterations in the expression of genes and proteins under the physical stress of space ‎flight and microgravity simulators.‎

The performance of the propulsion system and the engine, known as the heart of the aircraft, is highly dependent on subsystems, such as the engine control subsystem.Today, most modern military and civil aircraft use turbine engines to generate thrust. The engine control system is one of the most challenging aircraft control systems that has undergone significant changes and improvements over time. The goal of any engine control system is to provide maximum performance in each flight conditions. With the increase in requirements and the development of technology in propulsion systems, digital electronic engine control and full authority digital engine (electronics) control have replaced hydromechanical control. The purpose of this study is to present the development process of turbine engine control system historically and to find new methods of engine control. Depending on the complexity of the aircraft propulsion system engine, the engine control approach will be determined and designed.

The recent development of UAVs is due to progress in electronics, control, and computer science combined with mechanics and flight science. What is evident in society is more mention of the advantages and capabilities of this technology, and less attention is paid to the technical parameters and basic challenges of the technology. The UAVs capability has only been expressed in various ways without expressing the challenges to society and the advertisement on the import of this technology continues. Yet, some decision-makers consider this advanced and expensive device only for import and flashy records. On one hand, the present article aims to express the important parameters and challenges of this advanced technology by stating the background, types, and applications, more awareness, and a detailed understanding of the challenges for the wise choice of decision-makers and users. On the other hand, future research topics for researchers, designers, and manufacturers would be another output of the article.