English
Related papers

Related papers: Hourglass: an unpublished map projection by John P…

200 papers

The main goal of the paper is to solve some problems about shadow for the sphere generalized on the case of the ellipsoid. Here, the essence of the problem is to find the the minimal number of non-overlapping balls with centers on the…

Metric Geometry · Mathematics 2015-10-09 Tetyana Osipchuk , Maxim Tkachuk

Van-der-Meer method is used in hadron colliders for absolute luminosity calibration. In the letter the applicability of the method is discussed when particles desnsity is distorted by hour-glass effect next to interaction point. The study…

Accelerator Physics · Physics 2025-12-10 Anton Babaev

The Euclidean projection onto a convex set is an important problem that arises in numerous constrained optimization tasks. Unfortunately, in many cases, computing projections is computationally demanding. In this work, we focus on…

Optimization and Control · Mathematics 2021-09-22 Ilnura Usmanova , Maryam Kamgarpour , Andreas Krause , Kfir Yehuda Levy

The solution of the geodesic problem for an oblate ellipsoid is developed in terms of series. Tables are provided to simplify the computation. [This is an English translation of F. W. Bessel, Astronomische Nachrichten 4(86), 241-254 (1825).…

Computational Physics · Physics 2012-03-30 F. W. Bessel , Charles F. F. Karney , Rodney E. Deakin

In this paper we give explicit closed forms for the semi-reproducing kernels associated with thinplate spline interpolation on the sphere. Polyharmonic or thinplate splines for ${\mathbb R}^d$ were introduced by Duchon and have become a…

Classical Analysis and ODEs · Mathematics 2018-08-14 Rick K. Beatson , Wolfgang zu Castell

The geometry of a two-dimensional surface in a curved space can be most easily visualized by using an isometric embedding in flat three-dimensional space. Here we present a new method for embedding surfaces with spherical topology in flat…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Mihai Bondarescu , Miguel Alcubierre , Edward Seidel

In 1492, for the first time, an unknown ocean opened up before sailors: weeks of navigation and no idea how to pinpoint their location. Since ancient times, navigators had known how to determine latitude by using the North Star, but the…

History and Philosophy of Physics · Physics 2025-01-28 Alessandro De Angelis

In 1931 Elie Cartan constructed a geometry which was rarely considered. Cartan proposed a way to define an infinitesimal metric $ds$ starting from a variational problem on hypersurfaces in an $n$-dimensional manifold $\mathcal{M}$. This…

Differential Geometry · Mathematics 2012-11-13 Imsatfia Moheddine

The event horizon of the Schwarzschild black hole has been well studied and the singular behavior of the Schwarzschild metric on horizon is understood as a coordinate singularity rather than an essential singularity. One demonstration of…

General Relativity and Quantum Cosmology · Physics 2025-12-15 A. T. Eberlein , C. N. Pope

This paper presents a new approach for dimension reduction of data observed in a sphere. Several dimension reduction techniques have recently developed for the analysis of non-Euclidean data. As a pioneer work, Hauberg (2016) attempted to…

Methodology · Statistics 2021-05-27 Jang-Hyun Kim , Jongmin Lee , Hee-Seok Oh

H. A. Hayden [1] introduced the idea of semi-symmetric non-metric connection on a Riemannian manifold in (1932). Agashe and Chafle \cite{1} defined and studied semi-symmetric non-metric connection on a Riemannian manifold. In the present…

Differential Geometry · Mathematics 2017-11-06 S. K. Chaubey

It will not be an exaggeration to say that R A Fisher is the Albert Einstein of Statistics. He pioneered almost all the main branches of statistics, but it is not as well known that he opened the area of Directional Statistics with his 1953…

Methodology · Statistics 2024-05-29 Kanti V. Mardia

As is well-known, numerical experiments show that Napoleon's Theorem for planar triangles does not extend to a similar statement for triangles on the unit sphere $S^2$. Spherical triangles for which an extension of Napoleon's Theorem holds…

Analysis of PDEs · Mathematics 2024-03-06 Serena Dipierro , Lyle Noakes , Enrico Valdinoci

A convex polyhedron $P$ is $k$-equiprojective if all of its orthogonal projections, i.e., shadows, except those parallel to the faces of $P$ are $k$-gon for some fixed value of $k$. Since 1968, it is an open problem to construct all…

Computational Geometry · Computer Science 2010-09-14 Masud Hasan , Mohammad Monoar Hossain , Alejandro López-Ortiz , Sabrina Nusrat , Saad Altaful Quader , Nabila Rahman

In recent times, the theoretical study of the three-dimensional Edwards-Anderson model has produced several rigorous results on the nature of the spin-glass phase. In particular, it has been shown that, as soon as the overlap distribution…

Disordered Systems and Neural Networks · Physics 2013-12-11 A. Maiorano , G. Parisi , D. Yllanes

This paper proposes a new extrinsic calibration of kaleidoscopic imaging system by estimating normals and distances of the mirrors. The problem to be solved in this paper is a simultaneous estimation of all mirror parameters consistent…

Computer Vision and Pattern Recognition · Computer Science 2017-05-30 Kosuke Takahashi , Akihiro Miyata , Shohei Nobuhara , Takashi Matsuyama

Fitting concentric geometric objects to digitized data is an important problem in many areas such as iris detection, autonomous navigation, and industrial robotics operations. There are two common approaches to fitting geometric shapes to…

Computer Vision and Pattern Recognition · Computer Science 2021-03-10 Ali A. Al-Sharadqah , Lorenzo Rull

This is a user guide for the first version of our developed Maple library, named Singularity. The first version here is designed for the qualitative study of local real zeros of scalar smooth maps. This library will be extended for symbolic…

Dynamical Systems · Mathematics 2018-03-13 Majid Gazor , Mahsa Kazemi

In the present paper we use twistor theory in order to solve two problems related to harmonic maps from surfaces to Euclidean spheres $\mathbb{S}^n$. First, we propose a new approach to isoperimetric inequalities based on energy index.…

Differential Geometry · Mathematics 2019-06-05 Mikhail Karpukhin

Self-supervised surround-view depth estimation enables dense, low-cost 3D perception with a 360{\deg} field of view from multiple minimally overlapping images. Yet, most existing methods suffer from depth estimates that are inconsistent…

Computer Vision and Pattern Recognition · Computer Science 2026-04-14 Samer Abualhanud , Christian Grannemann , Max Mehltretter