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NIST Authors in Bold

Displaying 40926 - 40950 of 74223

The Metallurgical Analysis of Wrought Iron from the RMS Titanic

September 1, 2003
Author(s)
J J. Hooper, Timothy J. Foecke, L Graham, Timothy P. Weihs
In this paper, traditional metallography combined with image analysis, mechanical testing, and micromechanical modeling are used to understand the variation in the mechanical properties of wrought iron as a function of its microstructure. Thousands of

The NIST Charpy V-Notch Verification Program: Overview and Operating Procedures

September 1, 2003
Author(s)
Christopher N. McCowan, Thomas A. Siewert, D P. Vigliotti
Charpy impact testing is often specified as ,in acceptance test for structural materials, and companies performing acceptance tests are typically required to verify the performance of their impact machine periodically. The procedure for verifying the

Thermal Degradation of Marble: Indications From Finite-Element Modelling

September 1, 2003
Author(s)
T Weiss, S Siegesmund, Lin-Sien H. Lum
Microstructure-based finite element simulations were used to study theThermo-mechanical behavior of calcite marbles. Give the same microstructure, a strongly textured marble had smaller elastic strain energy and a distinct directional dependence of thermal

Ultra-High Molecular Weight Polyethylene Wear Particle Effects on Bioactivity

September 1, 2003
Author(s)
H. W. Fang, Stephen M. Hsu, J V. Sengers
Ultra-high molecular weight polyethylene (UHMWPE) wear particles have been recognized as one of the major causes of aseptic loosening in total joint replacements. Macrophage phagocytosis of wear particles induces human biological/physiological responses

Using Ontologies to Aid Navigation Planning in Autonomous Vehicles

September 1, 2003
Author(s)
Craig I. Schlenoff, Stephen B. Balakirsky, M Uschold, R Provine, S J. Smith
This paper describes a system whose overall goal is to utilize ontologies to enhance the capabilities and performance of autonomous vehicles, particularly in the area of navigation planning. Our approach is to develop an ontology of objects based upon a

Machining Cracks Revealed by Fractography

August 28, 2003
Author(s)
George D. Quinn, L K. Ives, S Jahanmir
Fractography detected and characterized the nature and size of strength limiting rods and bars in a sintered reaction bonder silicon nitride that was ground by a variety of procedures.

Moving Object Prediction for Off-Road Autonomous Navigation

August 25, 2003
Author(s)
Rajmohan Madhavan, Craig I. Schlenoff
The realization of on- and o.-road autonomous navigation of Unmanned Ground Vehicles (UGVs) requiresreal-time motion planning in the presence of dynamic objects with unknown trajectories. To successfully planpaths and to navigate in an unstructured

A Bridge for Scaling to Higher Resistance from the QHR

August 21, 2003
Author(s)
Randolph Elmquist, Dean G. Jarrett
A two-terminal bridge for resistance scaling directly from the quantum Hall resistance (QHR) to higher-resistance values now provides a secondary starting point in decade scaling at NIST, beginning at the 1 M(Ohm) resistance level. This cryogenic bridge

Changes and Improvements in the 10 k-ohm Special Calibration Service

August 21, 2003
Author(s)
George R. Jones Jr., Marlin E. Kraft, Randolph Elmquist
The 1(ohm) level of resistance has been the source of the lowest standard uncertainties for d.c. resistance calibrations. At the 10 k(ohm) level, equally good transport standards are available and many laboratories also rely on these standards. NIST uses

Expanding the Role of Finite State Machine Technology in Open Architecture Control

August 21, 2003
Author(s)
John L. Michaloski, Frederick M. Proctor, William G. Rippey, S Kolla
Modern machine control systems rely heavily on software to achieve system functionality. Until recently, control software?s primary purpose was to provide logic and sequencing of machine execution. With computer hardware now providing power and memory to

Temperature Scales Using Radiation Thermometers Calibratied From Absolute Irradiance and Radiance Responsivity

August 21, 2003
Author(s)
Howard W. Yoon, David W. Allen, Charles E. Gibson, Robert D. Saunders, Bettye C. Johnson, Steven W. Brown, Keith R. Lykke
In the International Temperature Scale of 1990 (ITS-90), temperatures above the freezing temperature of silver are defined with radiation thermometers calibrated using spectral radiance ratios to one of the silver-, gold- or copper-freezing temperature

User's Manual for Version 1.0 of the NIST DME Interface Test Suite for Facilitating Implementations of Version 1.1 of the I++ DME Interface Specification

August 21, 2003
Author(s)
John A. Horst, Thomas R. Kramer, Joseph A. Falco, Keith A. Stouffer, Hui-Min Huang, Frederick M. Proctor, Albert J. Wavering, Chengying Liu
This user's manual describes version 1.0 of the NIST Dimensional Measuring Equipment (DME) interface test suite intended to support implementations of version 1.1 of the I++ DME specification.

Induced Currents on an EUT in a Free-Space and a Modified TEM Cell Environment

August 19, 2003
Author(s)
Per E. Fornberg, Christopher L. Holloway, Perry F. Wilson
The finite-difference time-domain method is used to investigate whether the currents induced on an equipment under test (EUT) in a TEM cell are similar to those induced in an ideal free-space environment. The approach is to simulate an identical EUT in

Assessing A Loaded Reverberation Chamber: Calculating Threshold Metrics

August 18, 2003
Author(s)
Christopher L. Holloway, David A. Hill, John M. Ladbury, Todd M. Lammers
In this paper we present an expression for two threshold metrics of a loaded reverberation chamber. One metric is based on the chamber quality factor (Q) and the other is based on a useable volume of a loaded reverberation chamber. These metrics are

Evolution of a Performance Metric for Urban Search and Rescue Robots (2003)

August 18, 2003
Author(s)
Adam S. Jacoff, Brian Weiss, Elena R. Messina
This paper discusses the advancement and proliferation of the Reference Test Arenas for Urban Search and Rescue Robots as representative search and rescue environments, which allow objective performance evaluation of mobile robot capabilities. These arenas
Displaying 40926 - 40950 of 74223
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