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Related papers: Codes and caps from orthogonal Grassmannians

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We consider the problem of learning a linear subspace from data corrupted by outliers. Classical approaches are typically designed for the case in which the subspace dimension is small relative to the ambient dimension. Our approach works…

Computer Vision and Pattern Recognition · Computer Science 2019-11-11 Manolis C. Tsakiris , Rene Vidal

The Grassmannian manifold G(k, n) serves as a fundamental tool in signal processing, computer vision, and machine learning, where problems often involve classifying, clustering, or comparing subspaces. In this work, we propose a…

Signal Processing · Electrical Eng. & Systems 2025-05-01 Rémi Delogne , Laurent Jacques

In [I. Cardinali and L. Giuzzi. Line Hermitian Grassmann codes and their parameters. Finite Fields Appl., 51: 407-432, 2018] we introduced line Hermitian Grassmann codes and determined their parameters. The aim of this paper is to present…

Combinatorics · Mathematics 2020-05-13 Ilaria Cardinali , Luca Giuzzi

We analyse three related preconditioned steepest descent algorithms, which are partially popular in Hartree-Fock and Kohn-Sham theory as well as invariant subspace computations, from the viewpoint of minimization of the corresponding…

Numerical Analysis · Mathematics 2008-05-09 Reinhold Schneider , Thorsten Rohwedder , Alexej Neelov , Johannes Blauert

Let Gr(2, E) be the Grassmann bundle of two-planes associated to a general bundle E over a curve X. We prove that an embedding of Gr(2, E) by a certain twist of the relative Pl\"ucker map is not secant defective. This yields a new and more…

Algebraic Geometry · Mathematics 2015-01-07 Insong Choe , George H. Hitching

In a projective space we fix some set of points, a horizon, and investigate the complement of that horizon. We prove, under some assumptions on the size of lines, that the ambient projective space, together with its horizon, both can be…

Combinatorics · Mathematics 2013-05-22 Mariusz Żynel , Krzysztof Petelczyc

Given a finite Lie incidence geometry which is either a polar space of rank at least $3$ or a strong parapolar space of symplectic rank at least $4$ and diameter at most $4$, or the parapolar space arising from the line Grassmannian of a…

$\newcommand{\eps}{\varepsilon}$ In this paper, we consider two important problems defined on finite metric spaces, and provide efficient new algorithms and approximation schemes for these problems on inputs given as graph shortest path…

Computational Geometry · Computer Science 2021-02-23 David Eppstein , Sariel Har-Peled , Anastasios Sidiropoulos

We study the problem of $2$-dimensional orthogonal range counting with additive error. Given a set $P$ of $n$ points drawn from an $n\times n$ grid and an error parameter $\eps$, the goal is to build a data structure, such that for any…

Data Structures and Algorithms · Computer Science 2016-05-24 Zhewei Wei , Ke Yi

Every polygon $P$ can be companioned by a cap polygon $\hat P$ such that $P$ and $\hat P$ serve as two parts of the boundary surface of a polyhedron $V$. Pairs of vertices on $P$ and $\hat P$ are identified successively to become vertices…

Computational Geometry · Computer Science 2024-11-27 Mercedes Sandu , Shuyi Weng , Jade Zhang

Optical orthogonal signature pattern codes (OOSPCs) have attracted wide attention as signature patterns of spatial optical code division multiple access networks. In this paper, an improved upper bound on the size of an…

Combinatorics · Mathematics 2019-09-04 Rong Pan , Tao Feng , Lidong Wang , Xiaomiao Wang

Inspired by the artwork of Mark Lombardi, we study the problem of constructing orthogonal drawings where a small number of horizontal and vertical line segments covers all vertices. We study two problems on orthogonal drawings of planar…

Discrete Mathematics · Computer Science 2016-08-16 Md. Jawaherul Alam , Michael Dillencourt , Michael T. Goodrich

Although there are very algorithms for embedding graphs on unbounded grids, only few results on embedding or drawing graphs on restricted grids has been published. In this work, we consider the problem of embedding paths and cycles on grid…

Discrete Mathematics · Computer Science 2014-10-10 Asghar Asgharian Sardroud , Alireza Bagheri

In the point set embeddability problem, we are given a plane graph $G$ with $n$ vertices and a point set $S$ with $n$ points. Now the goal is to answer the question whether there exists a straight-line drawing of $G$ such that each vertex…

Computational Geometry · Computer Science 2020-05-13 Tanaeem M. Moosa , M. Sohel Rahman

In this paper, we continue our study of blade arrangements and the positroidal subdivisions which are induced by them on $\Delta_{k,n}$. A blade is a tropical hypersurface which is generated by a system of $n$ affine simple roots of type…

Combinatorics · Mathematics 2022-10-14 Nick Early

This paper proposes a generalized framework with joint normalization which learns lower-dimensional subspaces with maximum discriminative power by making use of the Riemannian geometry. In particular, we model the similarity/dissimilarity…

Computer Vision and Pattern Recognition · Computer Science 2017-11-20 Tianci Liu , Zelin Shi , Yunpeng Liu

We use the ideas of goal-oriented error estimation and adaptivity to design and implement an efficient adaptive algorithm for approximating linear quantities of interest derived from solutions to elliptic partial differential equations…

Numerical Analysis · Mathematics 2019-03-21 Alex Bespalov , Dirk Praetorius , Leonardo Rocchi , Michele Ruggeri

The construction of Grassmannian codes in some projective space is of highly mathematical nature and requires strong computational power for the resulting searches. In this paper was constructed, using GAP System for Computational Discrete…

Information Theory · Computer Science 2019-03-25 Ismael Gutiérrez García , Ivan Molina Naizir

In this paper we compute the dimension of the Grassmann embeddings of the polar Grassmannians associated to a possibly degenerate Hermitian, alternating or quadratic form with possibly non-maximal Witt index. Moreover, in the characteristic…

Algebraic Geometry · Mathematics 2020-05-13 Ilaria Cardinali , Luca Giuzzi , Antonio Pasini

In this paper we define codes over some Octonion integers. We prove that in some conditions these codes can correct up to two errors for a transmitted vector and the code rate of the codes is grater than the code rate of the codes defined…

Information Theory · Computer Science 2014-01-31 Cristina Flaut