Theodore Stanoev

Theodore Stanoev
Memorial University of Newfoundland · Department of Earth Sciences

Doctor of Philosophy

About

27
Publications
2,459
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33
Citations
Introduction
I am a Ph.D. student in geophysics with a focus on quantitative seismology. Specifically, we investigate the Earth through the use of Hookean solids, which serve as mathematical analogies for its physical and material properties.
Additional affiliations
September 2015 - present
Memorial University of Newfoundland
Position
  • PhD Student
September 2015 - present
Memorial University of Newfoundland
Position
  • Undergraduate Laboratory Teaching Assistant
May 2015 - August 2015
Memorial University of Newfoundland
Position
  • Research Assistant
Education
September 2010 - May 2015

Publications

Publications (27)
Preprint
A novel approach to velodrome design for UCI-regulated tracks is presented. The mathematical model uses differential geometry to form a three-dimensional ruled surface. The surface accounts for the safety zone, blue band, and track region, the latter of which is comprised of three types of segments: straight lines, the arcs of circles, and connecti...
Preprint
Full-text available
We model the power applied by a cyclist on a velodrome -- for individual time trials -- taking into account its straights, circular arcs, and connecting transition curves. The dissipative forces to be overcome by power are air resistance, rolling resistance, lateral friction and drivetrain resistance. Also, the power is used to increase the mechani...
Preprint
Full-text available
We model the instantaneous power applied by a cyclist on a velodrome -- for individual pursuits and other individual time trials -- taking into account its straights, circular arcs, and connecting transition curves. The forces opposing the motion are air resistance, rolling resistance, lateral friction and drivetrain resistance. We examine the cons...
Article
We present a strategy for selecting the values of model parameters by comparing walkaway Vertical Seismic Profiling data with a multilayered model in the context of Bayesian Information Criterion. We consider -wave traveltimes and assume elliptical polar velocity dependence. A model with different propagation speeds, depending on the angle of propa...
Preprint
Full-text available
We combine power-meter measurements with GPS measurements to study the model that accounts for the use of power by a cyclist. The model takes into account the change in elevation and speed along with adverse effects of air, rolling and drivetrain resistance. The focus is on estimating the resistance coefficients using numerical optimization techniq...
Preprint
Full-text available
We present a strategy for selecting the values of elasticity parameters by comparing walk-away vertical seismic profiling data with a multilayered model in the context of Bayesian Information Criterion. We consider $P$-wave traveltimes and assume elliptical velocity dependence. The Bayesian Information Criterion approach requires two steps of optim...
Preprint
We consider an anisotropic inhomogeneous model to simulate measured vertical-seismic-profile traveltimes. In this model, we assume that velocity increases linearly with depth and anisotropy is the result of elliptical velocity dependence. Using a series of sources in a line to a single receiver, we minimize the least-squares residual between measur...
Article
Full-text available
We prove the equivalence—under rotations of distinct terms—of different forms of a determinantal equation that appears in the studies of wave propagation in Hookean solids, in the context of the Christoffel equations. To do so, we prove a general proposition that is not limited to \({{\mathbb {R}}}^3\), nor is it limited to the elasticity tensor wi...
Preprint
Full-text available
We model the instantaneous power on a velodrome for individual pursuits, taking into account its straights, circular arcs, and connecting transition curves. The forces opposing the motion are air resistance, rolling resistance, lateral friction and drivetrain resistance. We examine the constant-cadence and constant-power cases, and discuss their re...
Preprint
Full-text available
For a constant power output, the mean ascent speed (VAM) increases monotonically with the slope. This property constitutes a physical background upon which various strategies for the VAM maximization can be examined in the context of the maximum sustainable power as a function of both the gear ratio and cadence.
Preprint
Full-text available
For a moving bicycle, the power meters respond to the propulsion of the centre of mass of the bicycle-cyclist system. Hence, an accurate modelling of power measurements|on a velodrome|requires a distinction between the trajectory of the wheels and the trajectory of the centre of mass. We formulate and examine an individual-pursuit model that takes...
Preprint
Power-meter measurements together with GPS measurements are used to study the model that accounts for the use of power by a cyclist. The focus is on estimating the coefficients of the air, rolling and drivetrain resistance, uncertainties of these estimates, as well as relations between them. Expressions used in the main text are derived in the appe...
Preprint
Power-meter measurements are used to study a model that accounts for the use of power by a cyclist. The focus is on relations between rates of change of model quantities, such as power and speed, both in the context of partial derivatives, where other quantities are constant, and Lagrange multipliers, where other quantities vary to maintain the imp...
Preprint
The anisotropy of an equivalent medium resulting from the Backus (1962) average is induced by the vertical inhomogeneity among its constituent layers. The velocity field of the constituent isotropic layers increases linearly with depth, which is assumed to be a good seismological description of sedimentary layers Slotnick (1959). We derive an analy...
Article
Full-text available
The only restriction on the values of the elasticity parameters is the stability condition. Within this condition, we examine Christoffel equation for nondetached qP slowness surfaces in transversely isotropic media. If the qP slowness surface is detached, each root of the solubility condition corresponds to a distinct smooth wavefront. If the qP s...
Article
Full-text available
As shown by Backus (J Geophys Res 67(11):4427–4440, 1962), the average of a stack of isotropic layers results in a transversely isotropic medium. Herein, we consider a stack of layers consisting of randomly oriented anisotropic elasticity tensors, which—one might reasonably expect—would result in an isotropic medium. However, we show—by means of a...
Preprint
Full-text available
We illustrate properties of guided waves in terms of a superposition of body waves. In particular, we consider the Love and SH waves. Body-wave propagation at postcritical angles--required for a total reflection--results in the speed of the Love wave being between the speeds of the SH waves in the layer and in the halfspace. A finite wavelength of...
Preprint
Full-text available
The only restriction on the values of the elasticity parameters is the stability condition. Within this condition, we examine Christoffel equation for nondetached $qP$ slowness surfaces in transversely isotropic media. If the $qP$ slowness surface is detached, each root of the solubility condition corresponds to a distinct smooth wavefront. If the...
Preprint
The purpose of this paper is to prove the equivalence$-$under rotations of distinct terms$-$of different forms of a determinantal equation that appears in the studies of wave propagation in Hookean solids, in the context of the Christoffel equations. To do so, we prove a general proposition that is not limited to ${\mathbb R}^3$, nor is it limited...
Article
Full-text available
In this paper, we examine the applicability of the approximation, fg‾≈f‾g‾\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\overline{f g}\approx \overline{f}\,\overline{g...
Article
Full-text available
As shown by Backus (1962), the average of a stack of isotropic layers results in a transversely isotropic medium. Herein, we consider a stack of layers consisting of a randomly oriented anisotropic elasticity tensor, which-one might expect-would result in an isotropic medium. However, we show-by means of a fundamental symmetry of the Backus average...
Article
Full-text available
In this paper, we continue the study of Bos et al. (2017b) regarding statistical and numerical considerations of the Backus (1962) product approximation. While the approximation is typically quite good for seismological scenarios, Bos et al. (2017b) demonstrate a physical scenario that could, in spite of the stability conditions for isotropic media...
Article
Full-text available
In general, the Backus average of an inhomogeneous stack of isotropic layers is a transversely isotropic medium. Herein, we examine a relation between this inhomogeneity and the strength of resulting anisotropy, and show that, in general, they are proportional to one another. There is an important case, however, in which the Backus average of isotr...
Article
Full-text available
In this paper, following the Backus (1962) approach, we examine expressions for elasticity parameters of a homogeneous generally anisotropic medium that is long-wave-equivalent to a stack of thin generally anisotropic layers. These expressions reduce to the results of Backus (1962) for the case of isotropic and transversely isotropic layers. In ove...
Article
We examine the sensitivity of the Love and the quasi-Rayleigh waves to model parameters. Both waves are guided waves that propagate in the same model of an elastic layer above an elastic halfspace. We study their dispersion curves without any simplifying assumptions, beyond the standard approach of elasticity theory in isotropic media. We examine t...
Article
Full-text available
We examine two types of guided waves: the Love and the quasi-Rayleigh waves. Both waves propagate in the same model of an elastic isotropic layer above an elastic isotropic halfspace. From their dispersion relations, we calculate their speeds as functions of the elasticity parameters, mass densities, frequency and layer thickness. We examine the se...

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Projects

Project (1)
Project
I'm working on a Ph.D. doing forward modelling and joint inversion of Love and quasi-Rayleigh (like Rayleigh only in layered media) waves, initially for isotropic media but eventually for layered transversely isotropic media, including the case where one of the layers is a Backus averaged equivalent medium of a series of thin isotropic or transversely isotropic layers.