English
Related papers

Related papers: On Estimating the Perimeter Using the Alpha-Shape

200 papers

In this paper we consider a network of spatially distributed sensors which collect measurement samples of a spatial field, and aim at estimating in a distributed way (without any central coordinator) the entire field by suitably fusing all…

Systems and Control · Computer Science 2018-05-23 Francesco Sasso , Angelo Coluccia , Giuseppe Notarstefano

Formula for the size of the scatterer is derived explicitly in terms of the scattering amplitude corresponding to this scatterer. By the scatterer either a bounded obstacle $D$ or the support of the compactly supported potential is meant

Analysis of PDEs · Mathematics 2020-08-26 Alexander G. Ramm

Simulating from a gamma distribution with small shape parameter is a challenging problem. Towards an efficient method, we obtain a limiting distribution for a suitably normalized gamma distribution when the shape parameter tends to zero.…

Computation · Statistics 2015-04-08 Chuanhai Liu , Ryan Martin , Nick Syring

We address the problem of estimating the spherical-harmonic power spectrum of a statistically isotropic scalar signal from noise-contaminated data on a region of the unit sphere. Three different methods of spectral estimation are…

Astrophysics · Physics 2009-11-13 F. A. Dahlen , Frederik J Simons

Existing methods for the estimation of stable distribution parameters, such as those based on sample quantiles, sample characteristic functions or maximum likelihood generally assume an independent sample. Little attention has been paid to…

Statistics Theory · Mathematics 2014-05-05 Adrian W. Barker

This work describes a novel image analysis approach to characterize the uniformity of objects in agglomerates by using the propagation of normal wavefronts. The problem of width uniformity is discussed and its importance for the…

Disordered Systems and Neural Networks · Physics 2009-11-10 Luciano da F. Costa , Giancarlo Mutinari , David Schubert

This paper studies the relationship between volume and surface uniform measures on n-dimensional p-balls under the p-norm. It is proved that for p=1, p=2 and p=infinity, and only for these values of p, radial projection maps a…

Statistics Theory · Mathematics 2025-11-20 Carlos Pinzón

Envelopes were recently proposed as methods for reducing estimative variation in multivariate linear regression. Estimation of an envelope usually involves optimization over Grassmann manifolds. We propose a fast and widely applicable…

Methodology · Statistics 2014-03-18 R. Dennis Cook , Xin Zhang

This article introduces a method for estimating the smoothness of a stationary, isotropic Gaussian random field from irregularly spaced data. This involves novel constructions of higher-order quadratic variations and the establishment of…

Statistics Theory · Mathematics 2015-10-30 Wei-Liem Loh

In this paper, we build an apparatus for measuring the optical transmittance and its uniformity for a semispherical surface at normal incidence; the system is primarily comprised of a traditional double-beam photometric framework and a…

Optics · Physics 2018-05-23 Shenghao Wang , Shijie Liu , Jianda Shao , Tianzhu Xu , Qi Lu , Shen Qi , Minghui Feng , Long Zhang

We study the problem of estimating the average of a Lipschitz continuous function $f$ defined over a metric space, by querying $f$ at only a single point. More specifically, we explore the role of randomness in drawing this sample. Our goal…

Data Structures and Algorithms · Computer Science 2011-01-21 Abhimanyu Das , David Kempe

The conformational behavior of a coarse-grained finite polymer chain near an attractive spherical surface was investigated by means of multicanonical Monte Carlo computer simulations. In a detailed analysis of canonical equilibrium data…

Soft Condensed Matter · Physics 2018-01-03 Handan Arkin , Wolfhard Janke

We study two different methods for inferring the parameters of a spheroid distribution from planar sections of a stationary spatial system of spheroids: one method first unfolds non-parametrically the joint size-shape-orientation…

Methodology · Statistics 2018-03-09 Markus Baaske , Felix Ballani , Alexandra Illgen

For a given point set $S$ in a plane, we develop a distributed algorithm to compute the $\alpha-$shape of $S$. $\alpha-$shapes are well known geometric objects which generalize the idea of a convex hull, and provide a good definition for…

Computational Geometry · Computer Science 2013-02-19 Harish Chintakunta , Hamid Krim

Spherical regression explores relationships between variables on spherical domains. We develop a nonparametric model that uses a diffeomorphic map from a sphere to itself. The restriction of this mapping to diffeomorphisms is natural in…

Other Statistics · Statistics 2017-02-06 Michael Rosenthal , Wei Wu , Eric Klassen , Anuj Srivastava

We construct a novel estimator for the diffusion coefficient of the limiting homogenized equation, when observing the slow dynamics of a multiscale model, in the case when the slow dynamics are of bounded variation. Previous research…

Statistics Theory · Mathematics 2018-07-04 Theodoros Manikas , Anastasia Papavasiliou

We investigate the optimal configurations of n points on the unit sphere for a class of potential functions. In particular, we characterize these optimal configurations in terms of their approximation properties within frame theory.…

Functional Analysis · Mathematics 2017-09-04 Martin Ehler , Kasso A. Okoudjou

A sphere is a fundamental geometric object widely used in (computer aided) geometric design. It possesses rational parameterizations but no parametric polynomial parameterization exists. The present study provides an approach to the optimal…

Numerical Analysis · Mathematics 2021-04-27 Aleš Vavpetič , Emil Žagar

In countries where population census data are limited, generating accurate subnational estimates of health and demographic indicators is challenging. Existing model-based geostatistical methods leverage covariate information and spatial…

Methodology · Statistics 2022-08-08 Peter A. Gao , Jon Wakefield

In this paper, we revisit computational methods to obtain an angular profile of optical scattering from a smooth surface, given a two-dimensional map of topographic height errors of the surface. Quick derivations of some traditional…

Optics · Physics 2025-06-12 Tomotada Akutsu , Hiroaki Yamamoto