In this communication, we propose a high scanning rate leaky-wave antenna (LWA) based on slow-wave substrate integrated waveguide (SIW) structure. The effect is introduced by etching periodical slots the top surface of SIW. LWA radiation subsequently realized introducing sinusoidal modulation to profile. Such structure significantly improves due small group velocity at region. Simulation and measured results indicate that proposed scans wide angle in narrow bandwidth near cutoff frequency...

With the proliferation of unmanned aerial vehicles (UAVs) and escalating electromagnetic environment in space, there has been growing attention research focus on strong effects protection design UAVs. This paper aims to introduce potential interference that UAVs may encounter during flight. It specifically concentrates three crucial subsystems: datalink system, flight control navigation power system. The goal is provide an overview current state UAVs, along with a discussion commonly...

Background Telerehabilitation is gaining popularity in European and American countries, but whether it can be successfully implemented China still lacks support from clinical studies. Objective This trial aimed to determine if a home-based telerehabilitation method clinically noninferior standard in-hospital face-to-face rehabilitation for elderly patients with total hip arthroplasty (THA) China. Methods multicenter randomized controlled was conducted January 2021 June 2022 at The First...

The variation principle widely used in structural dynamics analysis allows us to transform the differential equation of boundary value problem into a functional with extreme value. In recent years, it has been applied band-gap periodic structures. However, for beam-plate composite structures and ordinary boundaries, is relatively difficult traditional energy methods, such as Rayleigh–Ritz method, construct displacement functions that satisfy conditions. Hence, hybrid solution proposed this...

Fast nonsingular terminal sliding mode controllers (FNTSMCs) are proposed for underactuated spacecraft formation reconfiguration without either the radial or in-track thrust. A nonlinear dynamic model of is developed, which then linearized about circular reference orbits. Based on model, system controllability analyzed case. Due to loss control in a certain direction, disturbances consisting linearization errors and external perturbations do not enter from same channels as those inputs,...

Electrostatically charged spacecraft accelerates when orbiting a central body with magnetic field due to the induced Lorentz force. This force could be used as propellantless propulsion for orbital maneuvers. Such is referred spacecraft. Modeling Earth’s tilted dipole rotating Earth, this paper first presents analytical expressions that characterize motion of respect inclined low Earth orbit. Using information from line-of-sight observations and gyro measurements, coupled proposed dynamical...

The Lorentz force acted on a charged spacecraft via interaction with planetary magnetic field provides new means of propellantless electromagnetic propulsion. Active modulation the surface charge allows to perform orbital maneuvers. By assuming Earth’s could be modeled as tilted dipole that co-rotates Earth, nonlinear dynamical model describing motion respect J 2 -perturbed orbit is developed using Lagrangian mechanics. Two potential applications proposed model, Lorentz-augmented hovering...

In this article, a new manoeuvring strategy for the multiple geosynchronous satellites inspection problem is proposed. contrast to previous research, it can be used visit orbiting in different orbital planes an economical way. proposed mission scenario, several chasers are initially placed equatorial high eccentric orbit. Two manoeuvres exerted at perigee adjust apogee of chaser every inspection. Subsequently, targets will visited when they fly through ascending or descending nodes their...

Most of previous blind parameter estimation methods frequency hopping (FH) signals with a single channel do not adapt to overlapped signals, whereas the multi-channel-based ones are computationally much too expensive. Moreover, all single- and multiple-channel-based use batch processing techniques, they able give real-time estimates frequencies. This study establishes temporal autoregressive moving average (ARMA) model temporally FH which is then used detect hops once happen, track...