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

NIST Authors in Bold

Displaying 16076 - 16100 of 73893

Metamorphic Testing for Cybersecurity

June 27, 2016
Author(s)
Tsong Yueh Chen, Fei-Ching Kuo, Wenjuan Ma, Willy Susilo, Dave Towey, Jeff Voas, Zhi Q. Zhou
Testing is a major approach for the detection of software defects, including security vulnerabilities. This article introduces metamorphic testing (MT), a relatively new testing method, and discusses how the new perspective of MT can help to conduct

Powder Bed Layer Geometry

June 27, 2016
Author(s)
Michael L. McGlauflin, Shawn P. Moylan
This paper investigates the measurement of machine performance errors associated with the powder bed geometry of a commercially available laser additive manufacturing (AM) machine. The methodology is based on existing ISO/ANSI standards as employed in

Residual Stresses in Flow Drill Screwdriving of Aluminium Alloy Sheets

June 27, 2016
Author(s)
Justin L. Milner, Thomas H. Gnaeupel-Herold, Jamie D. Skovron
With an increase in fuel economy standards and the need for reducing emissions set for the automotive sector, has increased the demand for lightweight vehicles. It is well known that the single heaviest component of a passenger vehicle is the body

Surrogate Gas Prediction Model as a Proxy for {D}14C-Based Measurements of Fossil Fuel-CO2

June 27, 2016
Author(s)
Kevin J. Coakley, Benjamin Miller, Stephen A. Montzka, Colm Sweeney, Ben Miller, John B. Miller
In contrast to CO2 produced in the atmosphere by all other sources, CO2 produced by the combustion of fossil fuels is devoid of 14C. Thus, the measured 14C: 12C isotopic ratio of atmospheric CO2 (and its associated derived {Δ}14C value) is an ideal tracer

Variability of Sounder Measurements in Manufacturing Facilities

June 27, 2016
Author(s)
Jeanne Quimby, Alexandra Curtin, David R. Novotny, Chih-Ming Wang, Rick Candell
Uncertainties in the linear regression fit of Path Loss are derived from variability in position. These uncertainties are used to determine the required positional accuracy for channel sounder measurements.

Vibration-induced field fluctuations in a superconducting magnet

June 27, 2016
Author(s)
Joseph W. Britton, John J. Bollinger, Justin G. Bohnet, Brian C. Sawyer, Hermann Uys, Michael Biercuk
Superconducting magnets enable precise control of nuclear and electron spins, and are used in experiments that explore biological and condensed matter systems, and fundamental atomic particles. In high-precision applications, a common view is that that

Process improvements in the production of silicon immersion gratings

June 26, 2016
Author(s)
Cynthia Brooks, Benjamin Kidder, Michelle Grigas, Daniel Jaffe, Ulf Griesmann, Daniel Wilson, Richard Muller
We have explored a number of lithographic techniques and improvements to produce the resist lines that then define the grating groove edges of silicon immersion gratings. In addition to our lithographic process using contact printing with photomasks, which

Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

June 26, 2016
Author(s)
Qian Gong, David Content, Margaret Z. Dominguez, Thomas Emmett, Ulf Griesmann, Jeffrey Kruk, Catherine Marx, Bert Pasquale, Thomas Wallace
The slitless spectrometer plays an important role in the WFIRST mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies1. The concept of the compound grism as a

Machine Learning Strategy to Determine Cell Shape Phenotypes Associated with Micro-Environmental Cues

June 25, 2016
Author(s)
Desu Chen, Sumona Sarkar, Julian Candia, Carl G. Simon Jr., Wolfgang Losert, Joy P. Dunkers, Stephen J. Florczyk, Subhadip Bodhak, Meghan Driscoll
Cell morphology has been identified as a potential indicator of stem cell response and function in biomaterial environments. However, determination of cell shape phenotype in biomaterials is complicated by heterogeneous cell populations, heterogeneous

Josephson-Based Full Digital Bridge for High-Accuracy Impedance Comparisons

June 24, 2016
Author(s)
Frederic Overney, Nathan Flowers-Jacobs, Blaise Jeanneret, Alain Rufenacht, Anna Fox, Jason Underwood, Andrew D. Koffman, Samuel P. Benz
This paper describes a Josephson-based full digital impedance bridge capable of comparing any two impedances, regardless of type (R-C, R-L, or L-C), over a large frequency range. At the heart of the bridge are two Josephson arbitrary waveform synthesizer

Summary of the 2015 NIST Language Recognition i-Vector Machine Learning Challenge

June 24, 2016
Author(s)
Audrey N. Tong, Craig S. Greenberg, Alvin F. Martin, Desire Banse, John M. Howard, G R. Doddington, Danilo B. Romero, Douglas A. Reynolds, Lisa Mason, Tina Kohler, Jaime Hernandez-Cordero, Elliot Singer, Alan McCree, Lisa Mason
In 2015 NIST coordinated the first language recognition evaluation (LRE) that used i-vectors as input, with the goals of attracting researchers outside of the speech processing community to tackle the language recognition problem, exploring new ideas in

30 Years of Newest Vertex Bisection

June 23, 2016
Author(s)
William F. Mitchell
One aspect of adaptive mesh refinement in the finite element method for solving partial differential equations is the method by which elements are refined. In the early 1980’s the dominant method for refining triangles was the red-green algorithm of Bank

A Snapshot of 118 Solid State Lighting Testing Laboratories' Capabilities

June 23, 2016
Author(s)
C Cameron Miller, Hannah Hasting, Maria Nadal
The National Institute of Standards and Technology (NIST) began to offer proficiency testing for Solid-State Lighting (SSL) products through a Measurement Assurance Program (MAP) in 2010. The MAP program provided proficiency testing complimenting

DFT investigation of early stages of nanoindentation of Ni

June 23, 2016
Author(s)
Francesca M. Tavazza, Lyle E. Levine
Density functional theory simulations of diamond tips indenting Ni surfaces are used to study the early stages of nanoindentation. Numerous complex interactions are observed, including Ni-surface deformation during tip approach, the attachment and

Supramolecular Hydrophobic Aggregates in Hydrogels Partially Inhibit Ice Formation

June 23, 2016
Author(s)
Clinton G. Wiener, Madhu Sudan Tyagi, Yun Liu, R. A. Weiss, Bryan D. Vogt
Prevention of ice crystallization is a challenging problem with implications in diverse applications, including the ability to examine the fundamental low temperature physics of water. Here, we demonstrate a simple route, inspired by water confinement in

A precise instrument to determine the Planck constant, and the future kilogram

June 21, 2016
Author(s)
Darine El Haddad, Frank C. Seifert, Leon S. Chao, David B. Newell, Jon R. Pratt, Carl J. Williams, Stephan Schlamminger, Shisong Li
A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, the second and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck

Building Systems: Characterization and Impacts OVERVIEW

June 21, 2016
Author(s)
Andrew Persily
Characterize three building systems Building envelope, HVAC (heating, ventilating and air-conditioning) and interior surfaces Factors likely to impact the indoor microbiome Known links between systems and indoor microbiome
Displaying 16076 - 16100 of 73893
Was this page helpful?