Results 91 to 100 of about 84,456 (273)

Multi‐Dielectric Metasurfaces for Ultrabright, Tunable Structural Color and Reconfigurable Optical Filtering with Extraordinarily Large Color Span

Advanced Optical Materials, EarlyView.
Structural color generation is an emerging field for digital display and printing applications. This report presents a novel truncated‐cone design and the first use of GaP sandwiched between two layers of TiO2, demonstrating ultra‐bright, tunable colors with a record color gamut.
Md Rumon Miah, Yavuz Selim Aydın, Hilmi Volkan Demir   +2 more
wiley   +1 more source

Covert Communication Over the Poisson Channel

IEEE Journal on Selected Areas in Information Theory, 2021
We consider the problem of communication over a continuous-time Poisson channel subject to a covertness constraint: The relative entropy between the output distributions when a message is transmitted and when no input is provided must be small. In the absence of both bandwidth and peak-power constraints, we show the covert communication capacity of ...
openaire   +1 more source

Selective Reflection of Chiral Ferroelectric Nematic Liquid Crystals Tuned by Electric Field Along the Helix Axis

Advanced Optical Materials, EarlyView.
It is demonstrated that in chiral ferroelectric nematic liquid crystals sandwiched between electrically conducting transparent plates, the reflection color can be reversibly tuned by electric fields applied along the helix axis. The proposed theoretical model, assuming field‐induced coiling of the helix axis, accounts for all observations.
Md Sakhawat Hossain Himel, Rohan Dharmarathna, James T. Gleeson, Robert J. Twieg, Samuel Sprunt, Antal Jákli   +5 more
wiley   +1 more source

Strontium Charge‐Generation Assistant Layer for High‐Performance Tandem Organic Light Emitting Diodes

Advanced Optical Materials, EarlyView.
An ultrathin Sr interlayer is introduced as a charge‐generation assist layer to overcome the electron‐injection barrier in deep‐LUMO charge‐generation layers (CGLs) of tandem OLEDs. The Sr layer facilitates trap‐assisted tunneling and lowers the effective injection barrier, enabling improved charge balance and yielding tandem OLEDs with doubled ...
Hyo‐Bin Kim, Sung‐Cheon Kang, So‐Jeong Lim, Minsu Kim, Jang‐Kun Song   +4 more
wiley   +1 more source

Experimental unconditionally secure covert communication in dense wavelength-division multiplexing networks

, 2017
Covert communication offers a method to transmit messages in such a way that it is not possible to detect that the communication is happening at all. In this work, we report an experimental demonstration of covert communication that is provably secure ...
Arrazola, Juan Miguel, Li, Hao, Liu, Wen-Zhao, Liu, Yang, Pan, Jian-Wei, Primaatmaja, Ignatius William, Scarani, Valerio, Wang, Zhen, You, Lixing, Zhang, Qiang, Zhang, Weijun   +10 more
core  

Improving the Robustness of Visual Teach‐and‐Repeat Navigation Using Drift Error Correction and Event‐Based Vision for Low‐Light Environments

Advanced Robotics Research, EarlyView.
Visual teach‐and‐repeat (VTR) navigation allows robots to learn and follow routes without building a full metric map. We show that navigation accuracy for VTR can be improved by integrating a topological map with error‐drift correction based on stereo vision.
Fuhai Ling, Ze Huang, Tony J. Prescott
wiley   +1 more source

Towards a Framework for Covert Communications for Mitigating Traffic Detection Attacks

Computers
This article addresses a critical security challenge in Internet of Things (IoT) systems, which are vulnerable to traffic detection attacks due to their reliance on shared wireless communication channels.
Abdallah Farraj
doaj   +1 more source

GPCRs in CAR‐T Cell Immunotherapy: Expanding the Target Landscape and Enhancing Therapeutic Efficacy

Advanced Science, EarlyView.
Chimeric antigen receptor T cell therapy faces dual challenges of target scarcity and an immunosuppressive microenvironment in solid tumors. This review highlights how G protein‐coupled receptors can serve as both novel targets to expand the therapeutic scope and functional modules to enhance CAR‐T cell efficacy.
Zhuoqun Liu, Yuchen Xiao, Yamin Zhao, Lihe Dai, David J.H. Shih, Shikang Liang, Honglei Tian, Liu Liu, Feng Tian, Bing Liu, Lei Chang, Chao Zhang   +11 more
wiley   +1 more source

On Gaussian covert communication in continuous time [PDF]

EURASIP Journal on Wireless Communications and Networking, 2019
Abstract The paper studies covert communication over a continuous-time Gaussian channel. The covertness condition requires that the channel output must statistically resemble pure noise. When the additive Gaussian noise is “white” over the bandwidth of interest, a formal coding theorem is proven, extending earlier results on covert ...
openaire   +2 more sources

Photonic Time Crystals and Time‐Varying Electromagnetic Metamatter: A New Direction for Ultrafast Tunable Photonic and Microwave Materials and Devices

Advanced Science, EarlyView.
Photonic time crystals (PTCs) are systems in which electromagnetic parameters are modulated periodically in time, producing momentum bandgaps via temporal scattering rather than spatial Bragg processes. This review examines the theoretical frameworks, modeling, and computational tools for time‐varying media, and summarizes experimental demonstrations ...
Ranjan Kumar Patel, Shriram Ramanathan, Ronald P. Jenkins, Michael J. Carter   +3 more
wiley   +1 more source