This paper proposes the use of a trusted decoder and forward (DF) Unmanned Aerial Vehicle (UAV) relay to establish a covert communication between a terrestrial transmitter (Alice) and a receiver (Bob), which is located in a remote area outside the allowable transmitting radius of Alice. The terrestrial transmitter uses the Maximum Ratio Transmission (MRT) technique and several antennas to send the covert signal, and also the UAV relay operates in a Full-Duplex frequency band so that in addition to relaying Alice’s signal message to Bob, it also sends disturbance signals to increase the covert transmission detection error by the eavesdropping UAV. In this paper, the source-based jamming scheme (SBJ) is used to avoid the need of using an external jammer in the network. First, the covert transmission conditions in the mentioned network have been investigated and the optimal detection thresholds of the eavesdropping UAV have been obtained with respect to the terrestrial transmitter and the UAV relay. In the simulations, the effects of using multiple antennas at the transmitter as well as the location of the eavesdropping UAV have been investigated to indicate the effectiveness of the proposed covert communication relay scheme with the help of a UAV relay.

Optimized structural architect of an Unmanned Lambda Wing Aerial Vehicle (ULWAV) during conceptual design has proven to be a significant challenge due to its unconventional configuration and no historical data for the structural architect. This paper aims to develop a new approach for structural design layout of new generation unconventional aircraft especially for ULWAV. The first step in this approach is to investigate the affecting parameters on structural architecture of these aircrafts then using of modal analysis to identification the behavior of these unconventional geometries for a general methodology development. The result of this modal analysis is apportion aircraft geometry to conventional substructures with already well-established defined architect. ULWAV structure architecture has been done by combining the structural architecture of sub-sections and with respect to requirements for systems installation, stealth design objective and packaging requirements. Here the CATIA software is used to optimize general architect with parametric model. To validate the results, the maximum static stress and maximum displacement of the structure were calculated using MSC / Patran software and compared with the values obtained from the optimization process. Dynamic analysis and buckling stability of structural composite shells are also controlled below. The architect methodology was applied to a case study of an ULWAV. The weight of the optimized structure has also been confirmed by typical case study researches.

In this Paper, modeling, open-loop analysis and design of the centralized control system with the nonlinear control law of the dual-body UAV are discussed. In the two-body configuration, two completely identical aircrafts are connected to each other using a one-degree-of-freedom connection around the longitudinal body axis(hinge at the tips of the wings). The 6DOF dynamics of the of the two-body UAV is modeled using the Newton-Euler method. Changes in the behavior of two-bodied aircrafts in the form of different modes have also been investigated. Although the equations governing the flight of a double-body UAV are fully nonlinear and coupled, the nonlinear control laws for multi-body UAV have not been found in the articles in this field. Also, the control system developed by different teams is only decentralized, which increases the cost of the control system. In the present paper, the centralized control system with the nonlinear control law is proposed to solve the mentioned problems. The numerical simulation results show that the nonlinear control system has a better performance than the linear control and the time response graphs are very smooth and without any overshoots. The deviation angles of the control surfaces and trust levels are also limited and reasonable.

New technologies, including automatic and self-propelled UAVs, have always been discussed, whose application and use are subject to one of the rules of international law, and whether current international law is at all capable of responding to advances Scientific and military, and new technologies. The research is based on this assumption and seeks to state that modern technologies, such as UAVs, are subject to international law and require no new legislation or regulation. The study looked at UAVs at three levels of international air law and the Chicago Convention, International Humanitarian Law, and the important rules of these rights and multilateral export control regimes, and the role of UAVs in each of these three areas. And concludes that current international law has the ability to monitor and implement UAVs with current rules in the three areas mentioned.