Results 111 to 120 of about 3,285 (273)

Cyclostationary-based jammer detection for wideband radios using compressed sensing and artificial neural network

open access: yesInternational Journal of Distributed Sensor Networks, 2017
Cognitive radio is a promising technology for frequency allocation to improve the spectrum utilization efficiency of licensed bands. However, in recent years, the attention of the researchers is focused on security issues that have to be faced by ...
Tassadaq Nawaz   +2 more
doaj   +1 more source

Recent Advances on Wideband Spectrum Sensing for Cognitive Radio

open access: yes, 2014
Spectrum sensing plays a fundamental role in cognitive radio (CR) networks allowing to discover spectrum opportunities and enabling primary user (PU) protection.
Marco Chiani   +5 more
core   +1 more source

Benchmarking Coaxial and Angular Optical Emission Spectroscopy With Recommendations for Reliable Compositional In Situ Monitoring During Laser Powder Bed Fusion

open access: yesAdvanced Materials Technologies, EarlyView.
ABSTRACT Real‐time insight into local chemistry is critical for reliable part quality in additive manufacturing, especially laser powder bed fusion (PBF‑LB/M), where rapid thermal cycles and localized evaporation can undermine part performance. Optical emission spectroscopy (OES) offers non‑intrusive, in situ plume monitoring, but detection geometry ...
Philipp Gabriel   +4 more
wiley   +1 more source

High‐Power Rapid Laser‐Induced Synthesis of Multi‐functional Cobalt Metal‐Organic Framework With an Unprecedented Synthesis Efficiency

open access: yesAdvanced Materials Technologies, EarlyView.
Laser‐assisted synthesis enables rapid (within 1 h) and high‐yield (≥90%) production of Co‐MOFs with mesoporous structures, tunable magnetic and optical properties, and efficient adsorption of N2, CH4, and CO2 for low‐energy gas separation. DFT calculations elucidate the electronic structure and adsorption behavior.
Saliha Mutlu   +10 more
wiley   +1 more source

IRS Assisted Decentralized Learning for Wideband Spectrum Sensing

open access: yes
The increasing demand for reliable connectivity in industrial environments necessitates effective spectrum utilization strategies, especially in the context of shared spectrum bands. However, the dynamic spectrum-sharing mechanisms often lead to significant interference and critical failures, creating a trade-off between spectrum scarcity and under ...
Sicheng Liu   +5 more
openaire   +2 more sources

Highly Anisotropic Quasi‐Direct Organic Metal Halide Hybrids: A Platform for Polarization‐Sensitive Optoelectronics

open access: yesAdvanced Materials Technologies, EarlyView.
One‐dimensional C4N2H14PbBr4 is shown to have a quasi‐direct electronic band structure and strongly anisotropic transport with polarized broadband emission. A GW/Bethe–Salpeter excited‐state force formalism, supported by polarized Raman and temperature‐dependent photoluminescence, identifies low–frequency Pb–Br phonons that drive ultrafast exciton self‐
Rijan Karkee   +7 more
wiley   +1 more source

Tunable Extraordinary Optical Transmission in the Long‐Wavelength Infrared Range Using Electrostatic MEMS Actuation

open access: yesAdvanced Materials Technologies, EarlyView.
A MEMS‐integrated metamaterial filter enables continuous, low‐voltage spectral tuning in the long‐wavelength infrared (LWIR). The device employs extraordinary optical transmission in a dual suspended metasurface stack, where electrostatic actuation precisely controls the intermembrane air gap.
Oleg Bannik   +6 more
wiley   +1 more source

Cooperative Wideband Spectrum Sensing Based on Joint Sparsity

open access: yes, 2017
COOPERATIVE WIDEBAND SPECTRUM SENSING BASED ON JOINT SPARSITY By Ghazaleh Jowkar, Master of Science A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University Virginia ...
jowkar, ghazaleh
core   +1 more source

Tunable‐Threshold UV Dosimetry With Programmable Luminescent Tags via Oxygen‐Mediated Room‐Temperature Phosphorescence

open access: yesAdvanced Materials Technologies, EarlyView.
A fully organic UV threshold dosimeter is developed by exploiting the oxygen‐sensitive room‐temperature phosphorescence of a purely organic emitter in a polymer matrix. Upon reaching a specific cumulative UV dose, photochemical oxygen depletion triggers a sharp, high‐contrast emission.
Tim Achenbach   +3 more
wiley   +1 more source

Skin‐Like Tri‐Modal Sensors Based on Soft Piezoelectric and Ionic Composites

open access: yesAdvanced Materials Technologies, EarlyView.
Inspired by the multimodal perception of human skin, a soft, skin‐like tri‐modal sensor is presented. The device incorporates an ionically conductive, piezoelectric, elastic composite as its active layer, enabling independent detection of temperature, static strain, and dynamic strain within a single two‐terminal architecture.
Liren Wang   +9 more
wiley   +1 more source

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