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NIST Authors in Bold

Displaying 44576 - 44600 of 73461

The Philosophy of Information Retrieval Evaluation

September 24, 2001
Author(s)
Ellen M. Voorhees
Evaluation conferences such as TREC, CLEF, and NTCIR are modern examples of the Cranfield evaluation paradigm. In the Cranfield paradigm, researchers perform experiments on test collections to compare the relative effectiveness of different retrieval

Sub-dekahertz spectroscopy of 199 Hg +

September 21, 2001
Author(s)
J. C. Bergquist, R J. Rafac, B. A. Young, James A. Beall, Wayne M. Itano, David J. Wineland
Using a laser that is frequency locked to a Fabry-Perot etalon of high finesse and stability, we probe the 5d 106s 2S = (F=0, m f=0) 5d 96s 2 2 d5/2 (F=2, m f=0) electric-quadrupole transition of a single laser-cooled 199Hg + ion stored in a cryogenic

Large Eddy Simulation of Wood Combustion

September 19, 2001
Author(s)
Simo A. Hostikka, Kevin B. McGrattan
The purpose of this work is to study the coupling of the one-dimensional pyrolysis model to the computational fluid dynamics model for fire simulation. The large eddy simulation of the gas phase flow is combined with the combustion model using flame sheet

Acoustic Measurements in Gases, Chapter 10

September 15, 2001
Author(s)
Michael R. Moldover, Keith A. Gillis, John J. Hurly, J B. Mehl, J Wilhelm
Cylindrical acoustic resonators developed at the National Institute of Standards and Technology (NIST) are routinely used to measure the speed of sound in gases with uncertainties of 0.01% or less. The pressure dependence of the data is fitted with model

Speed of Sound as a Thermodynamic Property of Fluids

September 15, 2001
Author(s)
Daniel G. Friend
In this chapter, we review the principles of sound propagation in fluid systems. From a study of the hydrodynamic equations, sound propagation is shown to be a wave phenomenon. The speed of sound then can be derieved at any state point from a knowledge of

Microdisplay Metrology Research at NIST

September 14, 2001
Author(s)
Paul A. Boynton
Measuring the optical characteristics of a microdisplay produces challenges to traditional display metrology. When using light-measuring devices to measure scenes having high contrasts or wide color variations, the instruments suffer the effects of veiling

Development of Combustion and Radiation Models for Large Scale Fire Simulation

September 13, 2001
Author(s)
Kevin B. McGrattan, J E. Floyd, Glenn P. Forney, Simo A. Hostikka, Howard R. Baum
In cooperation with the fire protection engineering community, a numerical fire model, Fire DynamicsSimulator (FDS), is being developed at NIST to study fire behavior and to evaluate theperformance of fire protection systems in buildings. Version 1 of FDS

An Improved Voronoi-Diagram-Based Neural Net for Pattern Classification

September 12, 2001
Author(s)
Camillo A. Gentile, M Sznaier
In this brief paper, we propose a novel two-layer neural network to answer a point query in Rn which is partitioned into polyhedral regions. Such a task solves among others nearest neighbor clustering. As in previous approaches to the problem, our design

Harmonization of Standards

September 12, 2001
Author(s)
Belinda L. Collins, S Stanford
This paper is a summary of a workshop session during the Workshop on Biomedical Materials and Devices, held June 13 -14, 2001. The workshop is part of a series of workshops and topical meetings organized by NIST in the area of biomedical technology. The

Needs and Research Directions in Human-Robot Interactive Systems

September 12, 2001
Author(s)
V Lumelsky, Jean C. Scholtz
The advantages of using robotic systems will only be realized if non-experts in robotics are able to use the systems. This paper outlines some directions needed for research in human-robot interaction (HRI).

A Mercury-Ion Optical Clock

September 9, 2001
Author(s)
James C. Bergquist, U Tanaka, Robert E. Drullinger, Wayne M. Itano, David J. Wineland, Scott A. Diddams, Leo W. Hollberg, E A. Curtis, Christopher W. Oates, T Udem

Equation of State and Thermodynamic Properties of Pure Toluene and Dilute Aqueous Toluene Solutions in the Critical and Supercritical Regions

September 9, 2001
Author(s)
Sergei B. Kiselev, James F. Ely, Ilmutdin Abdulagatov, Emil Bazaev, Joe W. Magee
In this paper, we report new PVTx measurements for water + toluene binary mixtures at 11 near-critical and supercritical isotherms T = 623, 627, 629, 631, 633, 643, 645, 647, 649, 651, and 673 K and pressures up to 39 MPa at a fixed concentration of x = 0

Sapphire Statistical Strength Characterization

September 7, 2001
Author(s)
D R. McClure, R W. Cayse, S Goodrich, D McCullum, D C. Harris, K Lagerlof, C E. Patty, D H. Platus, Robert S. Polvani, David R. Black
Approximately 1400 4-point flexure specimens were tested at 300 K to 873 K to establish an engineering database for the strength of sapphire. Coupons represented material used for two missile windows and one missile dome. For one window, coupons were

Comparison of Concrete Rheometers: International Tests at LCPC (Nantes, France) in October 2000

September 5, 2001
Author(s)
Chiara F. Ferraris, L Brower, D Beaupre, F Chapdelaine, P Domone, E Koehler, L Shen, M Sonebi, Leslie Struble, D Tepke, O Wallevik, J Wallevik
The American Concrete Institute (ACI) sub-committee 236A, Workability of Fresh Concrete, upon its creation in fall 1999, immediately faced the task of determining appropriate methods to measure concrete workability. Using a material science-based approach
Displaying 44576 - 44600 of 73461
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