Results 41 to 50 of about 3,586 (255)

FAS for Secure and Covert Communications

IEEE Internet of Things Journal
This letter considers a fluid antenna system (FAS)-aided secure and covert communication system, where the transmitter adjusts multiple fluid antennas' positions to achieve secure and covert transmission under the threat of an eavesdropper and the detection of a warden.
Junteng Yao, Liangxiao Xin, Tuo Wu, Ming Jin 0001, Kai-Kit Wong, Chau Yuen, Hyundong Shin   +6 more
openaire   +2 more sources

Chip‐Integrated Metasurface‐GaAsSb Nanowire Array Photodetectors for Single‐Pixel Polarimetric Imaging

Advanced Optical Materials, EarlyView.
A 2×2 multiplexed GaAsSb nanowire photodetector array integrated with L‐shaped metasurfaces is developed for miniaturized infrared polarimetry. Leveraging non‐radiating anapole states that facilitate near‐field enhancement, the device demonstrates strong polarization selectivity at 835 nm.
Longsibo Huang, Ziyuan Li, Yitao Yang, Yang Yu, Lei Xu, Li Li, Songqin Zhang, Han Wang, Wenwu Pan, Chaohao Chen, Weiqi Jin, Wen Lei, Lorenzo Faraone, Chennupati Jagadish, Lan Fu   +14 more
wiley   +1 more source

Underwater Biomimetic Covert Acoustic Communications Mimicking Multiple Dolphin Whistles

, 2023
This paper presents an underwater biomimetic covert acoustic communication system that achieves high covertness and a high data rate by mimicking dolphin group whistles.
Hojun Lee, Bonggyu Park, Seunghwan Seol, Yongcheol Kim, Jaehak Chung   +4 more
core   +1 more source

Covert Communication in Mobile Applications (T)

2015 30th IEEE/ACM International Conference on Automated Software Engineering (ASE), 2015
This paper studies communication patterns in mobile applications. Our analysis shows that 63% of the external communication made by top-popular free Android applications from Google Play has no effect on the user-observable application functionality. To detect such covert communication in an efficient manner, we propose a highly precise and scalable ...
Rubin, Julia, Gordon, Michael I., Nguyen, Nguyen, Rinard, Martin C.   +3 more
openaire   +2 more sources

Surface‐Plasmon‐Coupled Blue InGaN/GaN Micro‐LEDs with Oxide–Metal–Oxide Capping Layer Compatible to Chip Fabrication Process

Advanced Optical Materials, EarlyView.
A sidewall‐integrated oxide–metal–oxide architecture is demonstrated to overcome efficiency degradation in ultra‐small InGaN/GaN micro‐LEDs. Conformal Al2O3 passivation combined with plasmonic Ag nanoparticles enables localized surface plasmon–exciton coupling, converting surface‐related nonradiative losses into radiative emission.
Pil‐Kyu Jang, Lee‐Woon Jang, Ohbin Kwon, Yeong‐Hoon Cho, Sangbum Kim, Sang‐Ik Lee, Seungjae Baek, Jiwon Park, Myeongjun Choi, Jaeseung Kim, Taehwan Kim, Sung‐Un Kim, Min‐Seok Lee, Yong‐Ho Ra, Ki Hoon Nam, Seung Min Kwak, Alexander Y. Polyakov, In‐Hwan Lee   +17 more
wiley   +1 more source

Covert Communication for Integrated Satellite–Terrestrial Relay Networks with Cooperative Jamming

, 2023
We explore the influence of cooperative jamming on covert communication for integrated satellite–terrestrial relay networks (ISTRN) in this article, where one full-duplex relay is utilized to support communications and acts as a jammer to confuse ...
Kefeng Guo, Shibing Zhu, Zeke Wu
core   +1 more source

Bridging Boltzmann and Non‐Boltzmann Optical Thermometry Enabled by Multimodal Perovskite Nanocrystals

Advanced Optical Materials, EarlyView.
Multimodal perovskite nanocrystals enable optical thermometry across multiple excitation and emission regimes, spanning the UV–Vis–NIR spectral range. By combining upconversion, downshifting, and persistent luminescence, the platform bridges conventional Boltzmann and non‐Boltzmann thermometric approaches.
Adrian Drozdowski, Kevin Soler‐Carracedo, Tomasz Grzyb   +2 more
wiley   +1 more source

Recent developments in covert acoustical communications

, 2022
S.243-254The topic of covert acoustical communication in air has produced public attention, lately. In 2013, we presented the fact that infected drones (e.g. laptops) might form covert acoustical mesh networks in air, only utilizing the built-in speakers
Goetz, Michael, Hanspach, Michael
core  

STAR-RIS Assisted Covert Communications in NOMA Systems [PDF]

, 2023
Covert communications assisted by simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) in non-orthogonal multiple access (NOMA) systems have been explored in this paper. In particular, the access point (AP) transmitter
Xiao, Han, Zheng, Tong-Xing, Wong, Kai-Kit, Hu, Xiaoyan   +3 more
core   +2 more sources

Neodymium‐Doped Nanocrystals for Sensing Cellular Temperature at the Nanoscale

Advanced Optical Materials, EarlyView.
Neodymium‐doped NaYF4 nanocrystals are engineered as bright, biocompatible nanothermometers for intracellular temperature mapping. Their ratiometric near‐infrared emission enables highly sensitive, nanoscale thermal readouts in living cells. Combined with gold nanostars for photothermal therapy, they reveal pronounced subcellular heating heterogeneity ...
Maria Bravo, Sandra Krzyzowska, Shelly Yang, Dingchen Wen, Jana Zielinski, Farsai Taemaitree, Samantha Zaman, Alastair Stewart, Susana Rocha, Paul Mulvaney, Hiroshi Uji‐i, Beatrice Fortuni, Sam Brooke, James Hutchison   +13 more
wiley   +1 more source