Christina Frederick

activity

20132026

most citedSeabed classification using physics-based modeling and machine learning

61 citations · 65 across the 6 of their papers we have counts for

collaborators

11 papers

math.AP2026

Velocity Reconstruction from Flow-Induced Magnetic Fields

Yacine Mokhtari, Christina Frederick, Yunan Yang +1

We study the inverse problem of reconstructing an incompressible velocity field $v$ from observations of the induced magnetic field $b$ . In the presence o…

math.FA2022

A characterization of Gabor Riesz bases with separable time-frequency shifts

Christina Frederick, Azita Mayeli

A Gabor system generated by a window function $g \in L^{2} (R^{d})$ and a separable set $Λ \times Γ \subset R^{2 d}$ is the collection of time-frequency shifts of $g$ give…

math.CA2020

Frame spectral pairs and exponential bases

Christina Frederick, Azita Mayeli

Given a domain $Ω \subset R^{d}$ with positive and finite Lebesgue measure and a discrete set $Λ \subset R^{d}$ , we say that $(Ω, Λ)$ is a {\it frame spectral pair} if the set o…

eess.SP2020★ 61 cited

Seabed classification using physics-based modeling and machine learning

Christina Frederick, Soledad Villar, Zoi-Heleni Michalopoulou

In this work model-based methods are employed along with machine learning techniques to classify sediments in oceanic environments based on the geoacoustic properties of a two-laye…

math.CA2019

Finding duality for Riesz bases of exponentials on multi-tiles

Christina Frederick, Kasso Okoudjou

It is known that if $Ω \subset R^{d}$ belongs to a class of multi-tiling domains when translated by a lattice $Λ$ , there exists a Riesz basis of exponentials for $L^{2} (Ω)$ …

math.OC2019

Collective motion planning for a group of robots using intermittent diffusion

Christina Frederick, Magnus Egerstedt, Haomin Zhou

In this work we establish a simple yet effective strategy, based on optimal transport theory, for enabling a group of robots to accomplish complex tasks, such as shape formation an…

math.CA2018

On the frame set of the second-order $B$ -spline

A. Ganiou D. Atindehou, Christina Frederick, Yébéni B. Kouagou +1

The frame set of a function $g \in L^{2} (R)$ is the set of all parameters $(a, b) \in R_{+}^{2}$ for which the collection of time-frequency shifts of $g$ along $a\mathbb{…

math.NA2016★ 4 cited

Seafloor identification in sonar imagery via simulations of Helmholtz equations and discrete optimization

Bjorn Engquist, Christina Frederick, Quyen Huynh +1

We present a multiscale approach for identifying features in ocean beds by solving inverse problems in high frequency seafloor acoustics. The setting is based on Sound Navigation A…

math.FA2016

An $L^{2} -$ stability estimate for periodic nonuniform sampling in higher dimensions

Christina Frederick

We consider sampling strategies for a class of multivariate bandlimited functions $f$ that have a spectrum consisting of disjoint frequency bands. Taking advantage of the special s…

math.NA2014

Numerical methods for multiscale inverse problems

Christina Frederick, Bjorn Engquist

We consider the inverse problem of determining the highly oscillatory coefficient $a^{ε}$ in partial differential equations of the form $- \nabla \cdot (a^{ε} \nabla u^{ε}) + b u^{ε} = f$ from gi…

math.NA2013

Nonuniform sampling and multiscale computation

Björn Engquist, Christina Frederick

In homogenization theory and multiscale modeling, typical functions satisfy the scaling law $f^{ε} (x) = f (x, x / ε)$ , where $f$ is periodic in the second variable and $ε$ is the smalles…