Now showing items 1-20 of 37

• #### An adaptive multiscale algorithm for efficient extended waveform inversion ﻿

(2017)
Subsurface-offset extended full-waveform inversion (FWI) may converge to kinematically accurate velocity models without the low-frequency data accuracy required for standard data-domain FWI. However, this robust alternative ...
• #### An Algebraic Exploration of Dominating Sets and Vizing's Conjecture ﻿

(2012)
Systems of polynomial equations are commonly used to model combinatorial problems such as independent set, graph coloring, Hamiltonian path, and others. We formulate the dominating set problem as a system of polynomial ...
• #### An approximate inverse to the extended Born modeling operator ﻿

(2015)
Given a correct (data-consistent) velocity model, reverse time migration (RTM) correctly positions reflectors but generally with incorrect amplitudes and wavelets. Iterative least-squares migration (LSM) corrects the ...
• #### A Comparison of High Order Interpolation Nodes for the Pyramid ﻿

(2015)
The use of pyramid elements is crucial to the construction of efficient hex-dominant meshes [M. Bergot, G. Cohen, and M. Duruflé, J. Sci. Comput., 42 (2010), pp. 345--381]. For conforming nodal finite element methods with ...
• #### Convergence of a high order method in time and space for the miscible displacement equations ﻿

(2015)
A numerical method is formulated and analyzed for solving the miscible displacement problem under low regularity assumptions. The scheme employs discontinuous Galerkin time stepping with mixed and interior penalty discontinuous ...
• #### Cytoplasmic sphingosine-1-phosphate pathway modulates neuronal autophagy ﻿

(2015)
Autophagy is an important homeostatic mechanism that eliminates long-lived proteins, protein aggregates and damaged organelles. Its dysregulation is involved in many neurodegenerative disorders. Autophagy is therefore a ...
• #### A DEIM Induced CUR Factorization ﻿

(2016)
We derive a CUR approximate matrix factorization based on the discrete empirical interpolation method (DEIM). For a given matrix ${\bf A}$, such a factorization provides a low-rank approximate decomposition of the form ...
• #### Edge Guided Reconstruction for Compressive Imaging ﻿

(2012-07-03)
We propose EdgeCS—an edge guided compressive sensing reconstruction approach—to recover images of higher quality from fewer measurements than the current methods. Edges are important image features that are used in various ...
• #### The Effects of Theta Precession on Spatial Learning and Simplicial Complex Dynamics in a Topological Model of the Hippocampal Spatial Map ﻿

(2014)
Learning arises through the activity of large ensembles of cells, yet most of the data neuroscientists accumulate is at the level of individual neurons; we need models that can bridge this gap. We have taken spatial learning ...
• #### An Efficient Gauss--Newton Algorithm for Symmetric Low-Rank Product Matrix Approximations ﻿

(2015)
We derive and study a Gauss--Newton method for computing a symmetric low-rank product $XX^{{T}}$, where $X \in{\mathbb{R}}^{n\times k}$ for $k<n$, that is the closest to a given symmetric matrix \$A \in{\mathbb{R}}^{n\times ...
• #### Filtering Deterministic Layer Effects in Imaging ﻿

(2012)
Sensor array imaging arises in applications such as nondestructive evaluation of materials with ultrasonic waves, seismic exploration, and radar. The sensors probe a medium with signals and record the resulting echoes, ...
• #### Genetic Suppression of Transgenic APP Rescues Hypersynchronous Network Activity in a Mouse Model of Alzeimer's Disease ﻿

(2014)
Alzheimer's disease (AD) is associated with an elevated risk for seizures that may be fundamentally connected to cognitive dysfunction. Supporting this link, many mouse models for AD exhibit abnormal electroencephalogram ...
• #### Horizontal contraction in image domain for velocity inversion ﻿

(2015)
A kinematically correct choice of velocity focuses subsurface offset image gathers at a zero offset. Infinitesimal warping from the current image toward its focus can be approximated by a horizontal contraction. The image ...
• #### Inverse Boundary Value Problem For The Helmholtz Equation: Quantitative Conditional Lipschitz Stability Estimates ﻿

(2016)
We study the inverse boundary value problem for the Helmholtz equation using the Dirichlet-to-Neumann map at selected frequencies as the data. A conditional Lipschitz stability estimate for the inverse problem holds in the ...
• #### Levetiracetam mitigates doxorubicin-induced DNA and synaptic damage in neurons ﻿

(2016)
Neurotoxicity may occur in cancer patients and survivors during or after chemotherapy. Cognitive deficits associated with neurotoxicity can be subtle or disabling and frequently include disturbances in memory, attention, ...
• #### Limited Memory Block Krylov Subspace Optimization for Computing Dominant Singular Value Decompositions ﻿

(2013)
In many data-intensive applications, the use of principal component analysis and other related techniques is ubiquitous for dimension reduction, data mining, or other transformational purposes. Such transformations often ...
• #### Local Error Analysis of Discontinuous Galerkin Methods for Advection-Dominated Elliptic Linear-Quadratic Optimal Control Problems ﻿

(2012-08-15)
This paper analyzes the local properties of the symmetric interior penalty upwind discontinuous Galerkin (SIPG) method for the numerical solution of optimal control problems governed by linear reaction-advection-diffusion ...
• #### A mathematical framework for inverse wave problems in heterogeneous media ﻿

(2013)
This paper provides a theoretical foundation for some common formulations of inverse problems in wave propagation, based on hyperbolic systems of linear integro-differential equations with bounded and measurable coefficients. ...
• #### A Matrix-Free Trust-Region SQP Method for Equality Constrained Optimization ﻿

(2014)
We develop and analyze a trust-region sequential quadratic programming (SQP) method for the solution of smooth equality constrained optimization problems, which allows the inexact and hence iterative solution of linear ...
• #### The Minimalﾠk-Core Problem for Modelingﾠ k-Assemblies ﻿

(2015)
The concept of cell assembly was introduced by Hebb and formalized mathematically by Palm in the framework of graph theory. In the study of associative memory, a cell assembly is a group of neurons that are strongly connected ...