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: Zachary H. Levine (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 148

Non-Uniqueness in Dual-Energy CT with Beam Hardening

September 13, 2017
Author(s)
Zachary H. Levine
Purpose: The goal is to determine whether dual-energy computed tomography (CT) leads to a unique reconstruction into two basis materials. Methods and Materials: The beam hardening equation is simplified to the single voxel case. The simplified equation is

Continuous-feed optical sorting of aerosol particles

June 15, 2016
Author(s)
John J. Curry, Zachary H. Levine
We consider the problem of sorting, by size, spherical particles of order 100 nm radius. The scheme we analyze consists of a heterogeneous stream of spherical particles flowing at an oblique angle across a Gaussian mode optical standing wave. Sorting is

Towards Estimating the Uncertainty Associated with 3D Geometry Reconstructions from Medical Image Data

May 23, 2016
Author(s)
Zachary H. Levine, Karim O. Genc, Stephen M. Luke, Todd Pietiela, Ross T. Cotton, Benjamin Ache, Phillipe G. Young, Marc Horner, Kevin C. Townsand
3D image based modeling for visualization, physics-based simulation or additive manufacturing, is becoming more common within R&D labs in academia, government and commercial industry. Computed Tomography (CT) is a common imaging modality used to obtain the

National Institute of Standards and Technology measurement service of the optical properties of biomedical phantoms: Current status

March 24, 2016
Author(s)
Paul Lemaillet, Catherine C. Cooksey, Zachary H. Levine, Adam L. Pintar, Jeeseong Hwang, David W. Allen
The National Institute for Standards and Technology (NIST) has maintained scales of reflectance and transmittance over several decades. Those scales are primarily intended for the regular transmittance, mirrors, and solid surface scattering diffusers. The

Adapting the Poisson-Influenced K-Means Algorithm for a Larger User Base

November 19, 2015
Author(s)
Brian P. Morris, Zachary H. Levine
A superconducting transition edge sensor (TES) can be a useful tool for counting the number of photons in a highly attenuated pulse of light, but it requires calibration for its outputs to be interpretable as photon numbers. The Poisson-Influenced K-Means

Absolute Calibration of a Variable Attenuator Using Few-Photon Pulses

June 12, 2015
Author(s)
Zachary H. Levine, Boris L. Glebov, Adam L. Pintar, Alan L. Migdall
We demonstrate the ability to calibrate a variable optical attenuator directly at the few photon level using a Superconducting Transition Edge Sensor (TES). Because of the inherent linearity of photon number resolving detection, no ex- ternal calibrations

Photon-number uncertainty in a superconducting transition-edge sensor beyond resolved-photon-number determination

September 10, 2014
Author(s)
Zachary H. Levine, Boris L. Glebov, Alan L. Migdall, Thomas Gerrits, Brice R. Calkins, Adriana E. Lita, Sae Woo Nam
As part of an effort to extend fundamental single-photon measurements into the macroscopic regime, we explore how best to assign photon-number uncertainties to output waveforms of a superconducting Transition Edge Sensor (TES) and how those assignments

Standard Reference Materials for Medical CT

June 27, 2013
Author(s)
Zachary H. Levine, Huaiyu H. Chen-Mayer, Adam L. Pintar, Daniel S. Sawyer
NIST Standard Reference Materials 2087 and 2088 for medical computed tomography (CT) have become available. The materials allow CT reconstructions to be tied to the International System of Units in length, density, and mass attenuation coefficient.

Fast, Optically Controlled Kerr Phase Shifter for Digital Signal Processing

April 18, 2013
Author(s)
Runbing Li, Lu Deng, Edward W. Hagley, Joshua Bienfang, Zachary H. Levine, Marvin G. Payne
We demonstrate an optically controlled Kerr phase shifter using a room-temperature Rb85 vapor operating in a Raman gain scheme. Phase shifts from zero to 𝜋 relative to an unshifted reference wave are observed, and gated operations are demonstrated. We

An algorithm for finding clusters with a known distribution and its application to photon-number resolution using a superconducting transition-edge sensor

July 20, 2012
Author(s)
Zachary H. Levine, Thomas Gerrits, Alan L. Migdall, Daniel V. Samarov, Brice R. Calkins, Adriana E. Lita, Sae Woo Nam
Improving photon-number resolution of single-photon sensitive detectors is important for many applications, as is extending the range of such detectors. Here we seek improved resolution for a particular Superconducting Transition-Edge Sensor (TES) through

Uncertainty in RECIST as a measure of volume for lung nodules and liver malignoma

April 27, 2012
Author(s)
Zachary H. Levine, Adam L. Pintar, John G. Hagedorn, Charles D. Fenimore, Claus P. Heussel
The authors investigate the extent to which the RESPONSE Evaluation Criateria in Solid Tumors (RECIST) can predict tumor volumes and changes in volume using clinical data. The data presented are a reanalysis of data acquired in other studies, including the

How to measure the size of tumors: The RECIST standard vs. volumetrics

July 11, 2011
Author(s)
Zachary H. Levine
Response Evaluation Criteria for Solid Tumours (RECIST) proposed 1D criteria for determining if 3D tumors are growing malignantly. Here, the error introduced is quantified using physical ellipsoids and fitting to clinical data on liver malignoma.

Tumor volume measurement errors RECIST studied with realistic tumor models

May 16, 2011
Author(s)
Benjamin R. Galloway, Adele Peskin, Zachary H. Levine
RECIST (Response Evaluation Criteria in Solid Tumors) is a linear measure intended to predict tumor volume in medical computed tomography (CT). In this work, using purely geometrical considerations, we estimate how well RECIST can predict the volume of

Tumor Volume Measurement Errors of RECIST Studied With Ellipsoids

May 5, 2011
Author(s)
Zachary H. Levine, Benjamin R. Galloway, Adele P. Peskin, C. P. Heussel, Joseph J. Chen
RECIST (Response Evaluation Criteria in Solid Tumors) is a linear measure intended to predict tumor volume in medical computed tomography (CT). In this work, using purely geometrical considerations, we establish limits for how well RECIST can predict the

Polarization-Entangled Photon Pairs From a Periodically Poled Cystalline Waveguide

March 23, 2011
Author(s)
Zachary H. Levine, Jingyun Fan, Jun Chen, Alan L. Migdall
A proposal is made for the generation of polarization-entangled photon pairs from a periodically poled crystal. The theory is formulated in terms of colinear propagation for application to waveguides. The key feature of the theory is the use of type 2