Results 11 to 20 of about 44,379 (259)

Approximate incidence geometry in the plane. [PDF]

Res Math Sci
Abstract These are lecture notes for a mini-course given in Banff in June 2024. They discuss the problem of bounding the number of $$\delta $$ δ
Orponen T.
europepmc   +4 more sources

Quotients of incidence geometries [PDF]

Designs, Codes and Cryptography, 2011
We develop a theory for quotients of geometries and obtain sufficient conditions for the quotient of a geometry to be a geometry. These conditions are compared with earlier work on quotients, in particular by Pasini and Tits. We also explore geometric properties such as connectivity, firmness and transitivity conditions to determine when they are ...
Philippe Cara, Alice Devillers, Michael Giudici, Cheryl E. Praeger   +3 more
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An Incidence Geometry approach to Dictionary Learning [PDF]

CoRR, 2014
We study the Dictionary Learning (aka Sparse Coding) problem of obtaining a sparse representation of data points, by learning \emph{dictionary vectors} upon which the data points can be written as sparse linear combinations. We view this problem from a geometry perspective as the spanning set of a subspace arrangement, and focus on understanding the ...
Meera Sitharam, Mohamad Tarifi, Menghan Wang   +2 more
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Large Incidence-free Sets in Geometries [PDF]

The Electronic Journal of Combinatorics, 2012
Let $\Pi = (P,L,I)$ denote a rank two geometry. In this paper, we are interested in the largest value of $|X||Y|$ where $X \subset P$ and $Y \subset L$ are sets such that $(X \times Y) \cap I = \emptyset$. Let $\alpha(\Pi)$ denote this value. We concentrate on the case where $P$ is the point set of $\mathsf{PG}(n,q)$ and $L$ is the set of $k$-spaces in
Stefaan De Winter, Jeroen Schillewaert, Jacques Verstraëte   +2 more
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Wind Direction Retrieval Using Spaceborne GNSS-R in Nonspecular Geometry

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2020
A wind direction retrieval algorithm using spaceborne global navigation satellite system reflectometry (GNSS-R) in nonspecular geometry is presented. This article first focuses on investigating the influence of wind direction on the scattering strength ...
Guodong Zhang, Dongkai Yang, Yongqing Yu, Feng Wang   +3 more
doaj   +1 more source

Engineering Chemisorption of Fe4 Single‐Molecule Magnets on Gold

Advanced Materials Interfaces, 2021
Gaining control over the grafting geometry is critically important for any application of surface‐supported single‐molecule magnets (SMMs) in data storage, spintronics, and quantum information science.
Lorenzo Poggini, Erik Tancini, Chiara Danieli, Andrea Luigi Sorrentino, Giulia Serrano, Alessandro Lunghi, Luigi Malavolti, Giuseppe Cucinotta, Anne‐Laure Barra, Amélie Juhin, Marie‐Anne Arrio, Weibin Li, Edwige Otero, Philippe Ohresser, Loïc Joly, Jean Paul Kappler, Federico Totti, Philippe Sainctavit, Andrea Caneschi, Roberta Sessoli, Andrea Cornia, Matteo Mannini   +21 more
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Polynomial effective equidistribution

Comptes Rendus. Mathématique, 2023
We prove effective equidistribution theorems, with polynomial error rate, for orbits of the unipotent subgroups of $\mathrm{SL}_2(\mathfrak{l})$ in arithmetic quotients of $\mathrm{SL}_2(\mathbb{C})$ and $\mathrm{SL}_2(\mathfrak{l})\times \mathrm{SL}_2 ...
Lindenstrauss, Elon, Mohammadi, Amir, Wang, Zhiren   +2 more
doaj   +1 more source

Research on influence of special-shaped honeycomb radar absorbing structure for wide-band absorbing design

The Journal of Engineering, 2019
To realise wide-band stealth of radar absorbing material, a special-shaped honeycomb radar absorbing structure within nested cone-shaped scattering configuration is designed.
Wang Ming-liang, Liu Jia-qi, Liu Xin, Zhao Xin-ying, Zhang Sheng-jun, Mu Lei, Ai Xia, Wan Guo-bin, Wang Wei-dong, Zhao Ju-yan   +9 more
doaj   +1 more source

Convex subspaces of Lie incidence geometries

Combinatorial Theory, 2022
Let \(\Gamma\) be a hexagonic Lie incidence structure, e.g.\ a long root geometry of a (thick irreducible) spherical Tits building; compare \textit{E. E. Shult} [Points and lines. Characterizing the classical geometries. Berlin: Springer (2011; Zbl 1213.51001)]. The authors classify all convex subspaces of \(\Gamma\) under the assumption that \(\Gamma\)
Meulewaeter, Jeroen, Van Maldeghem, Hendrik   +1 more
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Double Sided Band-pass Frequency Selective Surface Based on Matryoshka Geometry [PDF]

Journal of Microwaves, Optoelectronics and Electromagnetic Applications
This paper describes the development of a double-sided band-pass frequency selective surface based on Matryoshka geometry, preserving features such as miniaturization, multiband operation and stability of polarization and angle of incidence.
Marina de O. Alencar, Alfredo G. Neto, Marcos T. de Melo, Amanda G. Barboza   +3 more
doaj   +1 more source