Joint Deployment and Resource Management for VLC-enabled RISs-assisted UAV Networks

In this paper, the problem of the deployment and resource management for visible light communication (VLC)-enabled, reconfigurable intelligent surfaces (RISs)-assisted unmanned aerial vehicle (UAV) networks is investigated. In the considered model, UAVs provide terrestrial users with wireless services and illumination simultaneously. Moreover, RISs are utilized to further improve the channel quality between UAVs and users. This joint placement and resource management problem is constructed aiming at acquiring the optimal UAV deployment, RISs phase shift, user and RIS association that satisfies the users’ needs with minimum consumption of the UAVs’ energy. An iterative algorithm that alternately optimizes continuous and binary variables is proposed to solve this mixed-integer programming problem. Specifically, RISs phase shift optimization is solved by phases alignment method and semidefinite program algorithm. Next, the successive convex approximation algorithm is proposed to settle the UAV deployment problem. The user and RIS association variables are relaxed to the continuous ones before adopting the dual method to find the optimal solution. Moreover, a greedy algorithm is proposed as an alternative to RIS association optimization with low complexity. Simulation results show that the proposed two schemes harvest the superior performance of 34.85% and 32.11% energy consumption reduction over the case without RIS, respectively

The radiative lepton flavor violating decays in the split fermion scenario in the two Higgs doublet model

We study the branching ratios of the lepton flavor violating processes \mu -> e \gamma, \tau -> e \gamma and \tau -> \mu\gamma in the split fermion scenario, in the framework of the two Higgs doublet model. We observe that the branching ratios are relatively more sensitive to the compactification scale and the Gaussian widths of the leptons in the extra dimensions, for two extra dimensions and especially for the \tau -> \mu \gamma decay.Comment: 19 pages, 7 Figure

NOx and ultrafine particle emission characteristics in a new steel slag modification device

Two density-separated Chinese coals and steel slag were prepared and then combusted in a modification furnace with different excess air ratio. Non-staged and Fuel-staged combustion experiments were compared under different pulverized coal mixing ratios. Thus, in the fuel-staged combustion experiments, the concentration of NOx in the flue gas was found to greatly decrease under a bitumite: anthracite mixing ratio of 1:1 and an air excess coefficient of 1,2 under the fuel-staged ratio is 15:85. The flue gas temperature was as high as 1 615 °C, while the NOx concentration in the flue gas was as low as 320 mg/m3. Compared with the other types of burners, the experimental combustion device designed herein efficiently reduced the NOx emissions ca. 80%. Fuel-staged combustion has a significant effect on reducing particulate matter (PM) emissions, and a suitable coal ratio was also beneficial for reducing particulate matter emissions