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NIST Authors in Bold

Displaying 44951 - 44975 of 73697

Objective Speech Quality Measures for Internet Telephony

August 20, 2001
Author(s)
T Hall
Measuring voice quality for telephony is not a new problem. However, packet-switched, best-effort networks such as the Internet present significant new challenges for the delivery of real-time voice traffic. Unlike the circuit-switched PSTN, Internet

The Crystal Structure of Chorismate Lyase Shows a New Fold and a Tightly Retained Product

August 15, 2001
Author(s)
David T. Gallagher, M P. Mayhew, Marcia J. Holden, A J. Howard, K J. Kim, V L. Vilker
The enzyme chorismate lyase (CL) catalyzes the removal of pyruvate from chorismate to produce 4-hydroxy benzoate (4HB) for the ubiquinone pathway. In Escherichia coli, CL is monomeric with 164 residues; we have determined the structure of the CL product

Meander Delay Line Challenge Problem: A Comparison Using FDTD, FEM and MOM Techniques

August 13, 2001
Author(s)
Alpesh Bhobe, Christopher L. Holloway, Melinda Piket-May
Full wave finite-difference time-domain (FDTD) and a simplified 1D- finite-difference time-domain technique using the multi-conductor transmission line equations are applied to a delay line to determine its propagation characteristics. The output volatge

Biometric Authentication Technology: From the Movies to Your Desktop

August 7, 2001
Author(s)
Fernando L. Podio, J S. Dunn
Biometrics are automated methods of identifying a person or verifying the identity of a person based on a physiological or behavioral characteristic. Biometric authentication technologies such as face, finger, hand, iris, and speaker recognition are

NIST/BFRL CALIBRATION SYSTEM FOR HEAT-FLUX GAGES

August 6, 2001
Author(s)
William M. Pitts, James R. Lawson, John R. Shields
This report of test describes a heat-flux gage calibration system that was developed at the National Bureau of Standards during the 1970s. It is based on a commercial radiant heater incorporating a tungsten lamp and elliptical mirror. A kaleidoscope flux

Measuring Performance and Intelligence of Intelligent Sytems White Paper 2001

August 4, 2001
Author(s)
Elena R. Messina, Alex Meystel, Larry H. Reeker
Is the measurement of performance for intelligent systems different than that of non-intelligent systems? In this white paper, we explore the various dimensions of evaluation of intelligence and performance. The main areas we tackle are the testing of

A Feature-Based Inspection and Machining System

August 1, 2001
Author(s)
Thomas R. Kramer, Hui-Min Huang, Elena R. Messina, Frederick M. Proctor, Harry A. Scott
This paper describes an architecture for a system for machining and inspectingmechanical piece parts and an implementation of it called the Feature-BasedInspection and Control System (FBICS). In FBICS, the controller of a machiningcenter or coordinate

A Web-based 3D Glossary for Anthropometric Landmarks

August 1, 2001
Author(s)
Sanford P. Ressler
We have created a visual 3D anthropometric landmark glossary usable over the Web. Implemented using VRML, the Virtual Reality Modeling Language, users may easily locate and determine the names of these landmarks. Landmarks are visualized as small spheres

Absolute Extreme Ultraviolet Metrology

August 1, 2001
Author(s)
Charles S. Tarrio, Robert E. Vest, S Grantham
NIST has a long-standing program for the calibration of extreme ultraviolet optical components. Begun with the advent of the Synchrotron Ultraviolet Radiation Facility (SURF) almost 40 years ago, early activities centered on the development and

Active Monitoring and Control of Electron-Beam-Induced Contaminaition

August 1, 2001
Author(s)
Andras Vladar, Michael T. Postek, R Vane
The vacuum system of all scanning electron microscopes (SEMs), even in the so-called clean instruments, have certain hydrocarbon residues that the vacuum pumps do not effectively remove. The cleanliness of the vacuum and the amount and nature of these

Active Monitoring and Control of Electron-Beam-Induced Contamination

August 1, 2001
Author(s)
Andras Vladar, Michael T. Postek, R Vane
The vacuum systems of all scanning electron microscopes (SEMs), even in the so-called clean instruments, have certain hydrocarbon residues that the vacuum pumps do not effectively remove. The cleanliness of the vacuum and the amount and nature of these

Analysis of the Impedance Spectra of Short Conductive Fiber-Reinforced Composites

August 1, 2001
Author(s)
J M. Torrents, T Mason, A Peled, S Shah, Edward Garboczi
The presence of small amounts of short conductive fibers in a composite of finite matrix conductivity results in the subdivision of the one matrix impedance arc into two separate low and high frequency arcs in the complex impedance plane. These features

Analysis of the Impedance Spectra of Short Conductive Fiber-Reinforced Composites

August 1, 2001
Author(s)
Edward J. Garboczi, J M. Torrents, T O. Mason, A Peled, S P. Shah
The presence of small amounts of short conductive fibers in a composite of finite matrix conductivity results in the subdivision of the one matrix impedance arc into two separate low and high frequency arcs in the complex impedance plane. These features

Analyzing Broadband Free-Field, Absorber Measurements

August 1, 2001
Author(s)
David R. Novotny, Robert T. Johnk, Arthur Ondrejka
We present and analyze a method for free-field evaluation of broadband absorber in a non-ideal testing environment. Using broadband, short-impulse TEM horns, a frequency-rich spectrum (equivalent pulse length 0.5 ns) illuminates a sample of the material

Atmospheric Oxidation Mechanism of Methyl Pivalate, (CH 3 ) 3 CC(O)OCH 3

August 1, 2001
Author(s)
T J. Wallington, Y Ninomiya, M Mashino, M Kawasaki, Vladimir L. Orkin, Robert E. Huie, Michael J. Kurylo III
Flash photolysis-resonance fluorescence techniques were used to measure the rate constant for the reaction of OH radicals with methyl pivalate, (CH 3) 3CC(O)OCH 3 over the temperature range 250-370 K. The rate constant exhibited a weak temperature

BACnet Unraveled

August 1, 2001
Author(s)
Steven T. Bushby
Publication of ASHRAE and ANSI's BACnet communication protocol in 1995 ushered in a new era for building automation and control systems, making it possible to integrate building control products designed by different manufacturers. This change has proved

Building Integrated Photovoltaic Test Facility

August 1, 2001
Author(s)
Arthur H. Fanney, Brian P. Dougherty
The widespread use of building integrated photovoltaics appears likely as a result of the continuing decline in photovoltaic manufacturing costs, the relative ease in which photovoltaics can be incorporated within the building envelope, and the fact that

Ca 4 Nb 2 0 9 -CaTi0 3 : Phase Equilibria and Microstructures

August 1, 2001
Author(s)
Leonid A. Bendersky, Igor Levin, Robert S. Roth, Alexander J. Shapiro
Ca 4TiO 3-Ca 4Nb 2O 9 is a quasi-binary section, and all the phases participating in equilibrium are solid solutions of the binary end-members. The phases are perovskite-based ABO3-type, with a common stoichiometry Ca[Ca (1-x)/(3-2x)Nb (2-2x)/ (3-2x)Ti x/

Characterization of Thin and Ultrathin Polymer and Resist Films

August 1, 2001
Author(s)
D L. Goldfarb, Q Lin, M Angelopoulos, Christopher Soles, Eric K. Lin, Wen-Li Wu
The need for a better understanding of the physicochemical properties of radiation-sensitive thin polymer coatings for lithographic applications is driven by the trend of ever-shrinking pattern dimensions and film thickness, imposed by the semiconductor

Combinatorial Investigations of Polymer Adhesion

August 1, 2001
Author(s)
A J. Crosby, Alamgir Karim, Eric J. Amis
Combinatorial measurement methods allow material properties to be investigated in a multivariable space. These techniques could be especially attractive for investigating polymer adhesion that is determined by the complex coupling of bulk and interfacial

Comparison of Edge Detection Methods Using a Prototype Overlay Calibration Artifact

August 1, 2001
Author(s)
Richard M. Silver, Jay S. Jun, Edward A. Kornegay, R Morton
Accurate overlay measurements rely on robust, repeatable, and accurate feature position determination. In our effort to develop traceable we have examined a number of and the parameters which affect those measurements. The samples used in this study are a
Displaying 44951 - 44975 of 73697
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