With the widespread application of unmanned aerial vehicle (UAV) formation technology, it is very important to maintain good communication quality with the limited power and spectrum resources that are available. To maximize the transmission rate and increase the successful data transfer probability simultaneously, the convolutional block attention module (CBAM) and value decomposition network (VDN) algorithm were introduced on the basis of a deep Q-network (DQN) for a UAV formation communication system. To make full use of the frequency, this manuscript considers both the UAV-to-base station (U2B) and the UAV-to-UAV (U2U) links, and the U2B links can be reused by the U2U communication links.
View Article and Find Full Text PDFIn the process of using the Distributed Radar Network Localization System (DRNLS) further to improve the survivability of a carrier platform, the random characteristics of the system's Aperture Resource Allocation (ARA) and Radar Cross Section (RCS) are often not fully considered. However, the random characteristics of the system's ARA and RCS will affect the power resource allocation of the DRNLS to a certain extent, and the allocation result is an essential factor determining the performance of the DRNLS's Low Probability of Intercept (LPI). Therefore, a DRNLS still has some limitations in practical application.
View Article and Find Full Text PDFEntropy (Basel)
September 2021
Space-time adaptive processing (STAP) techniques have been motivated as a key enabling technology for advanced airborne radar applications. In this paper, a slow-time code design is considered for the STAP technique in airborne radar, and the principle for improving signal-to-clutter and noise ratio (SCNR) based on slow-time coding is given. We present two algorithms for the optimization of transmitted codes under the energy constraint on a predefined area of spatial-frequency and Doppler-frequency plane.
View Article and Find Full Text PDFPrevious studies have demonstrated that pyrogenic carbon can mediate the reductive degradation of pollutants in solutions containing reducing reagents under anaerobic conditions. However, few studies have investigated oxidative species formation and pollutants transformation directly mediated by pyrogenic carbon under aerobic conditions. In this study, we found that activated carbon (AC) can not only mediate reductive hexachloroethane degradation in the absence of O but also mediate the oxidation of As(III) and sulfanilamide in L-Cysteine (Cys, a naturally abundant thiol compound) solution under aerobic conditions.
View Article and Find Full Text PDFTo solve the problem of dwell time management for multiple target tracking in Low Probability of Intercept (LPI) radar network, a Nash bargaining solution (NBS) dwell time allocation algorithm based on cooperative game theory is proposed. This algorithm can achieve the desired low interception performance by optimizing the allocation of the dwell time of each radar under the constraints of the given target detection performance, minimizing the total dwell time of radar network. By introducing two variables, dwell time and target allocation indicators, we decompose the dwell time and target allocation into two subproblems.
View Article and Find Full Text PDFThe Surface enhanced fluorescence (SEF) and Surface Enhanced Raman Scattering (SERS) of Au nanoparticle films deposited on Si and SiO2 substrates are presented. From the experimental results, it is concluded that the fluorescence peak intensity changes in a similar way with the Raman intensity for the various substrates. Both the fluorescence and the Raman intensity were much stronger on SiO2 substrate than on the Si substrate.
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