The communications quality of unmanned aerial vehicle (UAV) has been brought into focus increasingly, which can be severely affected by other users, as well complex topography. In this letter, we propose a path planning algorithm for UAV anti-jamming with the joint assistance two kinds radio maps—signal power map and signal to interference plus noise ratio (SINR) map, contain abundant information loss caused topography from jammers. We show how generate these maps real topographic data,...

After disasters, road side units, which can provide wireless communications to vehicles, may fail due physical damages or power outages. Vehicle‐to‐vehicle communication also not perform well owing lack of neighbours in low vehicle density scenario collisions high circumstance happen disaster areas. In this study, the deployment unmanned aerial vehicles (UAVs) as flying base stations improve connectivity among affected areas is analysed. First, a function altitude UAV derived. Furthermore,...

In this paper, full-wave electromagnetic scattering theory is employed to investigate illusion and invisibility of inhomogeneous anisotropic cylinders spheres. With the use a shell designed according Mie series for multiple piecewise layers, radar cross section (RCS) coated object can be dramatically reduced or disguised as another in long-wavelength limit. suitable adjustment anisotropy parameters shell, optimal characteristics achieved. Details theoretical analysis numerical examples are...

Abstract The unmanned aerial vehicle (UAV) assisted mobile edge computing (MEC) system leverages the high maneuverability of UAVs to provide efficient services terminals. A dynamic deployment algorithm based on double deep Q-networks (DDQN) is suggested address issues with energy limitation and obstacle avoidance when providing terminals by UAV. First, consumption UAV fairness terminal’s geographic location are jointly optimized in case multiple obstacles ground. And can avoid obstacles....

In the framework of characteristic mode method (CMM) we develop a theoretical approach for achieving invisibility and illusion three-dimensional arbitrary-shaped objects. Starting from rigorous electromagnetic theory, wave interaction with arbitrarily shape scatterers is modelled by discrete-dipole approximation (DDA) method. By exploiting analysis, it theoretically shown that scattered field tightly related to generalized eigenvalues matrix in DDA A formulation designing thin homogeneous...

A challenging issue for a three-dimensional (3D) unmanned aerial vehicle (UAV) network is addressed in this paper - how do we efficiently establish and maintain one or multiple routes among swarm regions (i.e., groups of UAVs), during the dynamic swarming process? Inspired by human nervous system which can send brain signals to any tissue, propose 3D transformative routing (3D-TR) scheme, consists three novel designs: (1) Proactive skeleton establishment: 3D-TR first identifies UAV network,...

To improve the intelligence and accuracy of Situation Assessment (SA) in complex scenes, this work develops an improved fuzzy deep neural network approach to situation assessment for multiple Unmanned Aerial Vehicle(UAV)s. Firstly, normalizes scene data based on time series use normalized as input network. Secondly, adaptive momentum Elastic SGD (Elastic Stochastic Gradient Descent) are introduced into training process network, learning performance. Lastly, real-time task UAVs, conventional...

Satellite-terrestrial integrated networks (STINs) are considered to be a new paradigm for the next generation of global communication because its distinctive merits, such as wide coverage, high reliability, and flexibility. When satellite associates with different base stations (BSs) adopts channels communication, utility offloading data BSs is different. In our work, we study how jointly associate satellites appropriate allocate satellites. Our purpose maximize offloaded from while...

The characteristics of airborne multi-sensor task allocation problem are analyzed, and an model is established. In order to solve the problems local convergence slow traditional Particle Swarm Optimization (PSO) algorithm, structure parameters existing algorithm adjusted, direction coefficient far away factor introduced control velocity particle from worst solution, so that moves solution while moving optimal solution. Based on improved method proposed using maximum detection probability as...

Unmanned aerial vehicles (UAVs) received an unprecedented surge of people’s interest worldwide in recent years. This paper investigates the specific problem cooperative mission planning for multiple UAVs on battlefield from a hierarchical decision-making perspective. From view actual issue, two key problems to be solved UAV collaborative are allocation and route planning. In this paper, both these taken into account via model. Firstly, we use target clustering algorithm divide original...

The development of a dual-feed microstrip grid array antenna for either balanced or unbalanced operation to radiate pencil-beam patterns has been described. As an example, the on RT/duroid 5880 substrate with size 60 × 0.787 mm3 4.8λ 0.063λ at 24 GHz were designed and fabricated. measured results show that achieved excellent performances: 4.85% impedance bandwidth, 9.03% gain 20.6-dBi 24.15 as 6.05% 7.74% 17.8-dBi antenna. is suitable candidate radar sensor applications.

In this paper, a novel dual-band antenna for wireless local area networks (WLAN) application is designed and simulated. Firstly, standalone on smaller PCB satisfactory radiation patterns at 2.4 GHz 5.2 are achieved. Then, the integrated larger it found that become unsatisfactory, in particular GHz. order to improve patterns, four slots cut ground plane. The consists of meander strip quarter-ring GHz, both printed FR4 substrate with thickness 0.8 mm. final plane attains 9.3% impedance...

In this paper, a technique to modify finite flange open-ended coaxial probe for concave surface coating materials testing is proposed. It found from FDTD modeling and experimental results that by extending the inner conductor throughout air gap between sample adding ring patch at end, reflection coefficient measurement accuracy highly improved. The modified has been designed used measure EM-properties of microwave absorbing material coated on box shielding. Preliminary /spl epsi/* mu/* are...

Abstract When a total of 1114 rounds projectiles are fired, the grappling hook breechblock and pin locking mechanism break at place where cartridge case extraction takes place. A method combining experimental test theoretical analysis is used to analyze elastic-plastic deformation system. The fatigue life calculated be 1150 rounds. Through comprehensive improved design measures such as improvement load transfer path mechanism, local structure, material replacement, heat treatment process,...

In recent years, flight delay has become a problem that needs to be solved urgently. The of propagation prediction is studied in this thesis, which the phenomenon large area caused by an airport delay. analysis and advance can assist civil aviation departments controlling rate reducing economic loss delays. Firstly, national data cleaned filtered construct dataset chain affected At same time, errors or missing values are removed, related selected for subsequent modeling. Modeling performed...