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Increased data traffic resulting from the increase in the deployment of connected vehicles has become relevant in vehicular social networks (VSNs). To provide efficient communication between connected vehicles, researchers have studied device-to-device (D2D) communication. D2D communication not only reduces the energy consumption and loads of the system but also increases the system capacity by reusing cellular resources. However, D2D communication is highly affected by interference and therefore requires interference-management techniques, such as mode selection and power control. To make an optimal mode selection and power control, it is necessary to apply reinforcement learning that considers a variety of factors. In this paper, we propose a reinforcement-learning technique for energy optimization with fifth-generation communication in VSNs. To achieve energy optimization, we use centralized Q-learning in the system and distributed Q-learning in the vehicles. The proposed algorithm learns to maximize the energy efficiency of the system by adjusting the minimum signal-to-interference plus noise ratio to guarantee the outage probability. Simulations were performed to compare the performance of the proposed algorithm with that of the existing mode-selection and power-control algorithms. The proposed algorithm performed the best in terms of system energy efficiency and achievable data rate.
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http://dx.doi.org/10.3390/s20082361 | DOI Listing |
Nature
September 2025
National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA.
Controlling spin currents, that is, the flow of spin angular momentum, in small magnetic devices, is the principal objective of spin electronics, a main contender for future energy-efficient information technologies. A pure spin current has never been measured directly because the associated electric stray fields and/or shifts in the non-equilibrium spin-dependent distribution functions are too small for conventional experimental detection methods optimized for charge transport. Here we report that resonant inelastic X-ray scattering (RIXS) can bridge this gap by measuring the spin current carried by magnons-the quanta of the spin wave excitations of the magnetic order-in the presence of temperature gradients across a magnetic insulator.
View Article and Find Full Text PDFSci Rep
September 2025
Viet Tri University of Industry, Viet Tri City, 35100, Vietnam.
The tracked vehicle (TV) primarily operates on poor road surfaces, which means the vibration excitation of the road surface significantly impacts the driver's sighting efficiency and driving comfort. This is the cause of reduced vehicle combat efficiency. To address this, based on the dynamic interaction model between the TV, Seat, and Driver established in Matlab/Simulink software, all the dynamic parameters of the suspension system of the TV and seat are then simulated under different operation conditions of the TV.
View Article and Find Full Text PDFLight Sci Appl
September 2025
Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Tianjin, China.
Photon upconversion through high harmonic generation, multiphoton absorption, Auger recombination and phonon scattering performs a vital role in energy conversion and renormalization. Considering the reduced dielectric screening and enhanced Coulomb interactions, semiconductor monolayers provide a promising platform to explore photon upconversion at room temperature. Additionally, two-photon upconversion was recently demonstrated as an emerging technique to probe the excitonic dark states due to the extraordinary selection rule compared with conventional excitation.
View Article and Find Full Text PDFNat Commun
September 2025
Research Center Future Energy Materials and Systems of the Research Alliance Ruhr, Bochum, Germany.
The theoretical maximum critical temperature (T) for conventional superconductors at ambient pressure remains a fundamental question in condensed matter physics. Through analysis of electron-phonon calculations for over 20,000 metals, we critically examine this question. We find that while hydride metals can exhibit maximum phonon frequencies of more than 5000 K, the crucial logarithmic average frequency rarely exceeds 1800 K.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Department of Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, P. R. China.
Developing scalable and robust deicing coatings is essential for real-world applications, yet current coatings either suffer from intrinsic fragility or low thermal conductivity, limiting sustainability and deicing effectiveness. Here, we report a scalable and durable photothermal superhydrophobic coating coupling with enhanced thermal conductivity, engineered by embedding carbon nanotubes within a perfluoroalkoxy polymer matrix. Our design achieved 97.
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