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Search Publications by: Jun-Feng Song (Fed)

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Displaying 51 - 75 of 187

Assessment of Error Sources in Rockwell Hardness Measurements

October 16, 2008
Author(s)
Walter S. Liggett Jr, Samuel Low, David J. Pitchure, Jun-Feng Song
In the use of hardness test blocks, the uncertainty due to block non-uniformity can be reduced if one is willing to make measurements at specified locations on the blocks. Statistical methods for achieving this reduction are explained in this paper. The

NIST Microform Calibration System for Rockwell Hardness Standardization

August 25, 2008
Author(s)
Jun-Feng Song, Samuel R. Low III, Xiaoyu A. Zheng
In the uncertainty budget of Rockwell hardness tests, microform geometric errors of the diamond indenter are a major contributor. The microform calibration of Rockwell diamond indenters has been one of the key steps for Rockwell hardness standardization

Topography Measurements for Determining the Decay Factors in Surface Replication

July 4, 2008
Author(s)
Jun-Feng Song, P Rubert, Xiaoyu A. Zheng, Theodore V. Vorburger
The electro-forming technique is used at National Institute of Standards and Technology (NIST) for the production of standard reference material (SRM) 2461 standard casings to support nationwide ballistics measurement traceability and measurement quality

Surface Topography Analysis for a Feasibility Assessment of a National Ballistics Imaging Database

May 1, 2007
Author(s)
Theodore V. Vorburger, James H. Yen, B Bachrach, Thomas Brian Renegar, Li Ma, Hyug-Gyo Rhee, Xiaoyu Alan Zheng, Jun-Feng Song, Charles D. Foreman
This document reports on a study to determine the feasibility and utility of a national ballistics database of casing and bullet images. The purpose of such a proposed database would be to provide a reference collection of ballistic images against which

Comparison of Optical and Stylus Methods for Measurement of Rough Surfaces

January 1, 2007
Author(s)
Theodore V. Vorburger, H G. Rhee, Thomas B. Renegar, Jun-Feng Song, Xiaoyu A. Zheng
Abstract Optical methods are increasingly used for measurement of surface texture, particularly for areal measurements where the optical methods are generally faster. A new Working Group under Technical Committee (TC) 213 in the International Organization

NIST Standard Bullets and Casings Project

January 1, 2007
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou, Thomas Brian Renegar, Li Ma, Eric P. Whitenton, David R. Kelley, Robert A. Clary, A Zheng, M Ols
The National INstitute of Standards and Technology (NIST) standard bullets and casings project will provide support to firearm examiners and to the National Integrated Ballistics Information Network (NIBIN) in the United States. The standard bullet is

Correlation of Topography Measurements of NIST SRM 2460 Standard Bullets by Four Techniques

January 1, 2006
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Thomas Brian Renegar, Hyug-Gyo Rhee, A Zheng, L Ma, John M. Libert, Susan M. Ballou, B Bachrach, K Bogart
Three optical instruments including an interferometric microscope, a Nipkow disk confocal microscope and a laser scanning confocal microscope are used for the measurements of bullet profile signatures of a NIST (National Institute of Standards and

Correlation of Topography Measurements of NIST SRM 2460 Standard Bullets by Four Techniques

January 1, 2006
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Thomas Brian Renegar, Xiaoyu Alan Zheng, Hyug-Gyo Rhee, John M. Libert, Li Ma, K Bogart, Susan M. Ballou, B Bachrach
Three optical instruments including an interferometric microscope, a Nipkow disk confocal microscope and a laser scanning confocal microscope are used for the measurements of bullet profile signatures of a National Institute of Standards and Technology

Topography Measurements and Applications

January 1, 2006
Author(s)
Jun-Feng Song, Theodore V. Vorburger
Based on auto- and cross-correlation functions (ACF and CCF), a new surface parameter called profile (or topography) difference, Ds, has been developed for quantifying differences between 2D profiles or between 3D topographies with a single number. When Ds

Three-dimensional Scanning Optical Tweezers

December 5, 2005
Author(s)
Thomas W. LeBrun, T W. Hwang, I Y. Park, Jun-Feng Song, Yong-Gu Lee, Nicholas G. Dagalakis, Cedric V. Gagnon, Arvind K. Balijepalli
There are several new tools for manipulating microscopic objects. Among them, optical tweezers (OT) has two distinguishing advantages. Firstly, OT can easily release an object without the need of a complicated detaching scheme. Secondly, it is anticipated

2D and 3D Surface Texture Comparisons Using Autocorrelation Functions

January 1, 2005
Author(s)
Jun-Feng Song, Li Ma, Eric P. Whitenton, Theodore V. Vorburger
Autocorrelation and cross-correlation functions are proposed for 2D and 3D surface texture comparisons. At the maximum correlation point of the two correlated surface textures, there is a peak shown at the cross-correlation curve. It is proposed to

2D and 3D Surface Texture Comparisons Using Autocorrelation Functions

January 1, 2005
Author(s)
Jun-Feng Song, Li Ma, Eric P. Whitenton, Theodore V. Vorburger
Autocorrelation and cross-correlation functions are proposed for 2D and 3D surface texture comparisons. At the maximum correlaton point of the two correlated surface textrues, there is a peak shown at the cross-correaltion curve. It is proposed to generate

Deep-Penetrating Conical Cracks in Brittle Layers from Hydraulic Cyclic Contact

January 1, 2005
Author(s)
Yu Zhang, Jun-Feng Song, Brian R. Lawn
A study is made of fracture from cyclic loading of WC spheres on the top surfaces of thick (1 mm) brittle layers on polymeric substrates, as representative of repetitive occlusal contact on dental crown structures. The advantage of glass layers is that