U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Andrew Dienstfrey (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 58

Database of Diffusion MRI Brain Scans at 64 mT and 3 T

January 7, 2026
Author(s)
Andrew Dienstfrey, Zydrunas Gimbutas, Joe Chalfoun, Adele Peskin, Kalina Jordanova, Kathryn Keenan, Stephen Ogier
Low-field magnetic resonance imaging offers the promise to significantly increase access to in vivo soft tissue imaging. The technology is both portable and low-cost in relation to the high-field scanners in clinical use today. However, these gains are

Scaling of hardware-compatible perturbative training algorithms

April 17, 2025
Author(s)
Bakhrom Oripov, Andrew Dienstfrey, Adam McCaughan, Sonia Buckley
In this work, we explore the capabilities of Multiplexed Gradient Descent (MGD), a scalable and efficient perturbative zeroth-order training method for estimating the gradient of a loss function in hardware and training it via stochastic gradient descent

Layer ensemble averaging for fault tolerance in memristive neural networks

February 1, 2025
Author(s)
Osama Yousuf, Brian Hoskins, Karthick Ramu, Mitchell Fream, William Borders, Advait Madhavan, Matthew Daniels, Andrew Dienstfrey, Jabez McClelland, Martin Lueker-Boden, Gina Adam
Advancements in continual learning with artificial neural networks have been fueled in large part by scaling network dimensionalities. As this scaling continues, conventional computing systems are becoming increasingly inefficient due to the von Neumann

Device Modeling Bias in ReRAM-Based Neural Network Simulations

January 20, 2023
Author(s)
Imtiaz Hossen, Matthew Daniels, Martin Lueker-Boden, Andrew Dienstfrey, Gina Adam, Osama Yousuf
The study of resistive-RAM (ReRAM) devices for energy efficient machine learning accelerators requires fast and robust simulation frameworks that incorporate realistic models of the device population. Jump table modeling has emerged as a phenomenological

Bi-Criteria Radio Spectrum Sharing with Subspace-Based Pareto Tracing

March 22, 2022
Author(s)
Zachary J. Grey, Susanna Mosleh, Jake Rezac, Yao Ma, Jason Coder, Andrew Dienstfrey
Radio spectrum is a scarce resource. To meet demands, new wireless technologies must operate in shared spectrum over unlicensed bands (coexist). We consider coexistence of Long-Term Evolution (LTE) License-Assisted Access (LAA) with incumbent Wi-Fi systems

Optimizing Unlicensed Band Spectrum Sharing With Subspace-Based Pareto Tracing

August 6, 2021
Author(s)
Zachary Grey, Susanna Mosleh, Angela Folz, Yao Ma, Jason Coder, Andrew Dienstfrey
In order to meet the ever-growing demands of data throughput for forthcoming and deployed wireless networks, new wireless technologies like Long-Term Evolution License-Assisted Access (LTE-LAA) operate in shared and unlicensed bands. However, the LAA

Generalized source-conditions and uncertainty bounds for deconvolution problems

October 1, 2018
Author(s)
Jake D. Rezac, Andrew M. Dienstfrey, Nicholas A. Vlajic, Akobuije D. Chijioke, Paul D. Hale
Many problems in time-dependent metrology can be phrased mathematically as deconvolution problems. In such cases, measured data is modeled as the convolution of a known system response function with an unknown input signal, and the goal is to estimate the

Waveform metrology: Signal measurements in a modulated world

August 3, 2018
Author(s)
Paul D. Hale, Dylan F. Williams, Andrew M. Dienstfrey
In this work, we review the \full waveform metrology" concept that we introduced at the National Institute of Standards and Technology. Under this paradigm the full waveform and its functional representation is the target measurand. From the waveform

Magnetic Resonance Imaging Biomarker Calibration Service: Proton Spin Relaxation Times

May 3, 2018
Author(s)
Michael A. Boss, Andrew M. Dienstfrey, Zydrunas Gimbutas, Kathryn E. Keenan, Jolene D. Splett, Karl F. Stupic, Stephen E. Russek
This document describes the calibration service to measure proton spin relaxation times, T1 and T2, of materials used in phantoms (calibration artifacts) to verify the accuracy of MRI-based quantitative measurements. Proton spin relaxation times are used

Analysis, Comparison, and Assessment of Latent Fingerprint Preprocessing

July 20, 2017
Author(s)
Haiying Guan, Paul Y. Lee, Curtis L. Lamp, Andrew Dienstfrey, Mary Frances Theofanos, Brian Stanton, Matthew Schwarz
Latent fingerprints obtained from crime scenes are rarely immediately suitable for identification purposes. Instead, most latent fingerprint images must be preprocessed to enhance the fingerprint information held within the digital image, while suppressing

Calibration of Time-interleaved Errors in Real-time Digital Oscilloscopes

November 1, 2016
Author(s)
Jeffrey A. Jargon, Chihyun Cho, Joo-Gwang Lee, Paul D. Hale, Peter J. Jeavons, John B. Schlager, Andrew M. Dienstfrey
A novel method is proposed for the calibration of channel mismatch in a time-interleaved real- time digital oscilloscope (RTDO). A simple simultaneous equation is derived from the Fourier transform of the time-interleaved signals requiring only a transfer

On challenges in the uncertainty evaluation for time-dependent measurements

June 14, 2016
Author(s)
Sascha Eichstadt, Volker Wilkens, Andrew Dienstfrey, Paul D. Hale, Ben Hughes, Charles Jarvis
The measurement of quantities with time-dependent values is a common task in many areas of metrology. Although well established techniques are available for the analysis of such measurements, serious scientific challenges remain to be solved to enable
Was this page helpful?