Results 51 to 60 of about 3,586 (255)

Covert Voice over Internet Protocol communications based on spatial model

, 2016
This paper presents a new spatial steganography model for covert communications over Voice over Internet Protocol (VoIP), providing a solution to the issue of increasing the capacity of covert VoIP channels without compromising the imperceptibility of ...
Huang, Yongfeng, Tang, Shanyu
core   +1 more source

Millimeter-wave soldier-to-soldier communications for covert battlefield operations [PDF]

, 2009
Mobile ad hoc networking of dismounted combat personnel is expected to play an important role in the future of network-centric operations. High-speed, short-range, soldier-to-soldier wireless communications will be required to relay information on ...
Cotton, Simon, Scanlon, W.G., Madahar, Bob, Madahar, Bhopinder K., Scanlon, William, Cotton, Simon L.   +5 more
core   +1 more source

Red Fluorescent Protein‐Metal Organic Framework Hybrids for Lighting Applications

Advanced Optical Materials, EarlyView.
We demonstrate the encapsulation in a metal‐organic framework (MOF) of two red fluorescent proteins, DsRed and mCherry. The materials conserve all spectroscopical and structural properties of the underlying components, which allows for their implementation as color down‐converting materials in bio‐hybrid light‐emitting diodes, which exhibit average 3 ...
David Gutiérrez‐Armayor, Youssef Atoini, Rubén D. Costa   +2 more
wiley   +1 more source

When Cubic is Not Isotropic: Phonon–Exciton Decoupling in CuInSnS4 Single Crystals

Advanced Optical Materials, EarlyView.
A cubic CuInSnS4 crystal does not fully play by cubic rules. While phonons follow the average iso‐tropic lattice symmetry, the disorder‐localized excitons break away, showing strong, and reproduci‐ble polarization‐dependent emission. This work shows how intrinsic cation disorder can turn a mac‐roscopically cubic material into a source of hidden ...
Lara Kim Linke, Yvonne Tomm, Xinyun Liu, Galina Gurieva, Daniel M. Többens, Pardis Adams, Michel Calame, Ryan W. Crisp, Jessica Boland, Seán Kavanagh, Susan Schorr, Mirjana Dimitrievska   +11 more
wiley   +1 more source

Bayesian‐Optimized Dual‐Mode Luminescence‐Based Optical Thermometry Enabled by Negative Thermal Expansion in Lu2(MoO4)3:Yb–Er–Tm Phosphor

Advanced Optical Materials, EarlyView.
A Bayesian optimization framework identifies the ideal composition for Lu2(MoO4)3:Yb–Er–Tm phosphors with minimal experimental trials. By leveraging the host's negative thermal expansion, the material achieves remarkable thermal quenching compensation.
Reiko Furukawa, Takuya Hasegawa, Tong Fang, Saneyuki Ohno, Tomoyo Goto, Yasushi Sato, Ayahisa Okawa, Shu Yin   +7 more
wiley   +1 more source

Achievability of Covert Quantum Communication

2025 IEEE International Symposium on Information Theory (ISIT)
We explore covert communication of qubits over an arbitrary quantum channel. Covert communication conceals the transmissions in the channel noise, ensuring that an adversary is unable to detect their presence. We show the achievability of a $\textit{square root law}$ (SRL) for quantum covert communication similar to that for classical: $M(n)\propto ...
Evan J. D. Anderson, Michael S. Bullock, Filip Rozpedek, Boulat A. Bash   +3 more
openaire   +2 more sources

Machine Learning Enables Inverse Design of Optically Driven Microscopic Metavehicles

Advanced Optical Materials, EarlyView.
Machine‐learning‐based inverse design is used optimize “metavehicles” — flat microparticles based on metagratings that generate a strong lateral optical force from normally incident light. The optimized design exhibits a force efficiency of ∼88% and a measured propulsion speed in water much higher than previously reported, demonstrating that inverse ...
Vasilii Mylnikov, Mahdi Shanei, Mikael Käll   +2 more
wiley   +1 more source

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

Covert Federated Learning via Intelligent Reflecting Surfaces

, 2023
Over-the-air computation (OAC) is a promising technology that can achieve rapid model aggregation by utilizing the wireless waveform superposition feature to harness the interference of multiple-access channel for wireless federated learning (FL ...
Kang, Jiawen, Ren, Jie, Zheng, Jie, Gao, Ling, Jiawen Kang, Haijun Zhang, Niyato, Dusit, Jie Ren, Zhang, Haijun, Ling Gao, Jie Zheng, Dusit Niyato   +11 more
core   +1 more source

A Low‐Cost, Handheld Optical Stiffness Sensor for Minimally Invasive Surgery

Advanced Robotics Research, EarlyView.
A novel handheld stiffness sensor is presented for real‐time tissue stiffness characterization. By simultaneously sensing contact force and tissue deformation, the device enables accurate stiffness quantification without requiring precise manual control. This approach offers a promising solution for intraoperative tumor detection and minimally invasive
Qianyu Ma, Ruxiang Jiang, Kaspar Althoefer, Nicolas Herzig, Hareesh Godaba   +4 more
wiley   +1 more source