Universal characteristics of particle shape evolution by bed-load chipping

Abstract

Sediments moved by wind, rivers, and waves round in the same way due to geometry.

SediNet: A configurable deep learning model for mixed qualitative and quantitative optical granulometry

“…Paterson & Heslop, 2015), sediment abrasion (e.g. Novak-Szabo et al, 2018), hydraulic resistance (e.g. Rickenmann & Recking, 2011), particle settling (e.g.…”

A new workflow for the automated measurement of shape descriptors of rocks

“…Traditional measurement techniques often incorporate personal factors or rely on the verbal characterization of the shape (Wentworth, 1923;Boggs, 2001) to approximate these values. The number of stable (S) and unstable (U ) mechanical equilibria of a particle as a shape descriptor gained significant attention recently (Domokos et al, 2009; Miller et al, 2014;Domokos et al, 2015;Novák-Szabó et al, 2018) and it is not only insensitive for small measurement errors, but it also has a rich mathematical literature (Grayson, 1987;Domokos et al, 2015;Domokos and Lángi, 2019).…”

“…Traditional measurement techniques often incorporate personal factors or rely on the verbal characterization of the shape (Wentworth, 1923;Boggs, 2001) to approximate these values. The number of stable (S) and unstable (U ) mechanical equilibria of a particle as a shape descriptor gained significant attention recently (Domokos et al, 2009; Miller et al, 2014;Domokos et al, 2015;Novák-Szabó et al, 2018) and it is not only insensitive for small measurement errors, but it also has a rich mathematical literature (Grayson, 1987;Domokos et al, 2015;Domokos and Lángi, 2019).It is beneficial to switch from the traditional hand-measurements to automated shape analysis of the particles to avoid personal bias. Recently, several works appeared aiming to reduce subjectivity by automatically calculating shape properties from 2D digital images of the particles (Roussillon et al, 2009;Durian et al, 2007;Cassel et al, 2018;Cheng et al, 2018), 25 3D laser scanning (Hayakawa and Oguchi, 2005; Anochie-Boateng et al, 2013) or X-ray CT (Deiros Quintanilla et al, 2019).…”

Identification of Primary Shape Descriptors on 3D Scanned Particles

“…In some cases there is partial overlap; these cases we list below: a) axis ratios (for main approximate axes a>b>c we have p=c/a, q=b/a) have been broadly used in the geological literature [10][11][12], however, few rigorous mathematical results are available [13]. b) the isoperimetric ratio I is related to the classical roundness measure of pebbles [14], it is increasingly used in recent works [5,6,15] and there are also mathematical results available [16,17]. c) the number N of mechanical equilibria (i.e.…”

“…c) the number N of mechanical equilibria (i.e. the number N of critical points of the distance function measured from the center of mass) has also been used increasingly in recent years [5,15,18,19] and there is significant mathematical background available [17,20,21].…”