Results 41 to 50 of about 18,831 (324)

Modified Hand–Eye Calibration Using Dual Quaternions

Applied Sciences, 2022
This paper presents a modified model for hand–eye calibration based on dual quaternion algebra. By using dual quaternions to represent the rotations and translations of a rigid body simultaneously in the task space, the formulation is elegant for the ...
Guozhi Li, Shuizhong Zou, Shuxue Din, Bin Qi   +3 more
doaj   +1 more source

Hopfield Neural Networks for Online Constrained Parameter Estimation With Time‐Varying Dynamics and Disturbances

International Journal of Adaptive Control and Signal Processing, EarlyView.
This paper proposes two projector‐based Hopfield neural network (HNN) estimators for online, constrained parameter estimation under time‐varying data, additive disturbances, and slowly drifting physical parameters. The first is a constraint‐aware HNN that enforces linear equalities and inequalities (via slack neurons) and continuously tracks the ...
Miguel Pedro Silva
wiley   +1 more source

Asymptotic and Mittag–Leffler Synchronization of Fractional-Order Octonion-Valued Neural Networks with Neutral-Type and Mixed Delays

Fractal and Fractional, 2023
Very recently, a different generalization of real-valued neural networks (RVNNs) to multidimensional domains beside the complex-valued neural networks (CVNNs), quaternion-valued neural networks (QVNNs), and Clifford-valued neural networks (ClVNNs) has ...
Călin-Adrian Popa
doaj   +1 more source

Demonstration of an All‐Optical AND Gate Mediated by Photochromic Molecules

Advanced Functional Materials, EarlyView.
A logic AND gate that runs on photons is demonstrated. It relies on two spatially separated photochromic molecules that work in tandem. Abstract The realization of a photonic logic AND gate, i.e. a logic AND gate that runs on photons rather than electrons, and where all steps are controlled by light, is demonstrated. In a proof‐of‐principle experiment,
Heyou Zhang, Max Gießübel, Pankaj Dharpure, Andrea Albert, Vira Niestierkina, Paul Mulvaney, Mukundan Thelakkat, Jürgen Köhler   +7 more
wiley   +1 more source

Orders in quaternion algebras

Journal für die reine und angewandte Mathematik (Crelles Journal), 1989
The authors define and study the arithmetic of special orders in quaternion division algebras over number fields. Special orders are analogous to orders of the form \(\left( \begin{matrix} Z\\ NZ\end{matrix} \begin{matrix} Z\\ Z\end{matrix} \right)\) in \(Mat(2,{\mathbb{Q}}_ p)\) and include maximal and Eichler orders as special cases.
Hijikata, H., Pizer, A., Shemanske, T.
openaire   +3 more sources

Visualizing Quaternion Multiplication

IEEE Access, 2017
Quaternion rotation is a powerful tool for rotating vectors in 3-D; as a result, it has been used in various engineering fields, such as navigations, robotics, and computer graphics. However, understanding it geometrically remains challenging, because it
Jongchan Baek, Hayeong Jeon, Gwangjin Kim, Soohee Han   +3 more
doaj   +1 more source

Counting and effective rigidity in algebra and geometry

, 2018
The purpose of this article is to produce effective versions of some rigidity results in algebra and geometry. On the geometric side, we focus on the spectrum of primitive geodesic lengths (resp., complex lengths) for arithmetic hyperbolic 2-manifolds ...
A Borel, A Borel, A Lubotzky, A Lubotzky, A Lubotzky, A Macbeath, A Pethő, AM Odlyzko, AS Golsefidy, AW Reid, AW Reid, B Brindza, B Datskovsky, B Linowitz, B Linowitz, B Linowitz, B Linowitz, Benjamin Linowitz, C Maclachlan, C Maclachlan, C Millichap, C Millichap, D Futer, D Goldfeld, D Goldfeld, D. B. McReynolds, DA Marcus, DB McReynolds, DB McReynolds, E Artin, E Wirsing, G Prasad, GA Margulis, GA Margulis, GH Hardy, H Cohen, H Cohen, H Cohn, H Davenport, H Delange, H Delange, H Huber, I Reiner, J Neukirch, J Tits, J-P Serre, JC Lagarias, JS Meyer, JWS Cassels, K Takeuchi, L Hajdu, Lola Thompson, M Belolipetsky, M Belolipetsky, M Belolipetsky, M Bhargava, M Burger, M Larsen, M Liebeck, M-F Vignéras, MM Wood, MS Raghunathan, P Buser, Paul Pollack, R Gangolli, RS Pierce, S Brueggeman, S Lang, S Louboutin, S Wang, T Chinburg, T Chinburg, T Chinburg, T Chinburg, T Chinburg, T Gelander, T Gelander, T Sunada, TM Apostol, V Platonov, VI Chernousov, W Rudin, WP Thurston   +82 more
core   +1 more source

Hyperbolic unit groups and quaternion algebras [PDF]

Proceedings - Mathematical Sciences, 2009
We Classify the rational quadratic extensions K and the finite groups G for which the group ring R[G] of G over the ring R of integers of K has the property that the group of units of augmentation 1 of R[G] is hyperbolic. We also construct units in a non-split quaternion algebra over R.
Juriaans, S. O., Passi, I. B. S., Souza Filho, A. C.   +2 more
openaire   +2 more sources

Unprecedented Spin‐Lifetime of Itinerant Electrons in Natural Graphite Crystals

Advanced Functional Materials, EarlyView.
Graphite exhibits extraordinary spintronic potential, with electron spin lifetimes reaching 1,000 ns at room temperature ‐ over 100 times longer than graphene‐based devices. Magnetic resonance spectroscopy reveals strong anisotropy: out‐of‐plane spins live 50 times longer than their in‐plane counterparts.
Bence G. Márkus, Dávid Beke, Lili Vajtai, András Jánossy, László Forró, Ferenc Simon   +5 more
wiley   +1 more source

Holographic Whole‐Object Photopolymerization Preserving Director Alignment in Liquid Crystalline Actuators

Advanced Materials, EarlyView.
Holographic microlithography enables the fabrication of fully connected 3D liquid crystalline structures in a single exposure. The process maintains precise control over the director orientation within the entire object, preventing local director distortions typically observed in sequential printing.
Lovish Gulati, Junhee Lee, Reza Norouzikudiani, Jianfeng Li, Carlos Sánchez Somolinos, Antonio DeSimone, Kai Melde, Alexander Song, Peer Fischer   +8 more
wiley   +1 more source