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Search Publications by: Jun-Feng Song (Fed)

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Displaying 26 - 50 of 146

Applications of Surface Metrology in Toolmark Identification

January 8, 2014
Author(s)
Xiaoyu Alan Zheng, Johannes A. Soons, Theodore V. Vorburger, Jun-Feng Song, Thomas Brian Renegar, Robert M. Thompson
Surface metrology is commonly used to characterize functional engineering surfaces. The technologies developed offer opportunities to improve forensic toolmark identification. In 2009, a report by the National Academies called into question, amongst others

The Effect of Tip Size in Calibration of Surface Roughness Specimens with Rectangular Profiles

September 2, 2013
Author(s)
Jun-Feng Song, Thomas B. Renegar, Johannes A. Soons, Balasubramanian Muralikrishnan, John S. Villarrubia, Xiaoyu A. Zheng, Theodore V. Vorburger
For the calibration of rectangular and trapezoidal profile roughness specimens, stylus tip will increase profile peak width and decrease valley width, which may cause the Ra changes (either increase or decrease, depends on the profile shape). Sometimes the

Topography Measurements and Performance Comparisons between NIST SRM 2460 Standard Bullet Masters and BKA Bullet Replicas

July 31, 2012
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Robert M. Thompson, Susan M. Ballou, Xiaoyu Alan Zheng, Thomas Brian Renegar, Richard M. Silver
Two Standard Reference Material (SRM) 2460 Bullets produced by the National Institute of Standards and Technology (NIST) were used as masters for the fabrication of replica bullets at the Bundeskriminalamt (BKA). The surface topography of the SRM masters

Development of Ballistics Identification - From Image Comparison to Topography Measurement in Surface Metrology-

March 22, 2012
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Robert M. Thompson, Thomas Brian Renegar, Xiaoyu Alan Zheng, James H. Yen, Richard M. Silver, Wei Chu
Fired bullets and ejected cartridge cases have unique ballistics signatures left by the firearm. By analyzing the ballistics signatures, forensic examiners can trace these bullets and cartridge cases to the firearm used in a crime scene. Current automated

Stylus Tip-Size Effect on the Calibration of Periodic Roughness Specimens with Rectangular Profiles

March 21, 2012
Author(s)
Thomas B. Renegar, Johannes A. Soons, Balasubramanian Muralikrishnan, John S. Villarrubia, Xiaoyu A. Zheng, Theodore V. Vorburger, Jun-Feng Song
Stylus instruments are widely used for surface characterization. It is well known that the size and shape of the stylus tip affects the measured surface geometry and parameters. In most cases, increasing the tip size decreases the measured Ra value because

The National Ballistics Imaging Comparison (NBIC) Project

March 10, 2012
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou, Robert M. Thompson, James H. Yen, Thomas Brian Renegar, Xiaoyu Alan Zheng, Richard M. Silver, Martin Ols
In response to the guidelines issued by the ASCLD/LAB-International (American Society of Crime Laboratory Directors/Laboratory Accreditation Board) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project

An Iterative Algorithm for Calculating Stylus Radius Unambiguously

September 24, 2011
Author(s)
Theodore V. Vorburger, Xiaoyu A. Zheng, Thomas B. Renegar, Jun-Feng Song, Li Ma
The stylus radius is an important specification for stylus instruments and is commonly provided by instrument manufacturers. However, it is difficult to measure the stylus radius unambiguously. Accurate profiles of the stylus tip may be obtained by

GEOMETRICAL MEASUREMENTS OF NIST SRM ROCKWELL HARDNESS DIAMOND INDENTERS

November 21, 2010
Author(s)
Jun-Feng Song, Samuel R. Low III, Xiaoyu A. Zheng
The geometric parameters of 28 candidate Standard Reference Material (SRM) Rockwell hardness diamond indenters are calibrated by an automated system recently developed at the National Institute of Standards and Technology (NIST). The calibration results

Striation Density for Predicting the Identifiability of Fired Bullets

September 1, 2010
Author(s)
Wei Chu, Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou
Without a selection procedure to exclude the bullets having insufficient individualized ballistics signature, automated ballistics identification systems will correlate an evidence bullet with all reference bullets stored in the database. Correlations that

Topography measurements for correlations of standard cartridge cases

July 1, 2010
Author(s)
Theodore V. Vorburger, Jun-Feng Song, Wei Chu, Thomas Brian Renegar, Xiaoyu Alan Zheng, James H. Yen, Robert M. Thompson, Richard M. Silver, Benjamin Bachrach, Martin Ols
NIST Standard Reference Materials (SRM) 2460 Standard Bullets and 2461 Standard Cartridge Cases are intended for use as check standards for crime laboratories to help verify that their computerized optical imaging equipment for ballistics image

Applications of Cross-Correlation Functions

April 14, 2010
Author(s)
Theodore V. Vorburger, Jun-Feng Song, Wei Chu, Li Ma, Xiaoyu A. Zheng, Thomas B. Renegar, Son H. Bui
We describe several examples where we use cross-correlation functions to quantify the similarity of 2D surface profiles or of 3D surface topography images. The applications have included 1) the manufacture of Standard Reference Material (SRM) bullets and

Three steps towards metrological traceability for ballistics signature measurements

February 1, 2010
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Robert M. Thompson, Thomas Brian Renegar, Xiaoyu Alan Zheng, Li Ma, James H. Yen, Martin Ols
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 bullets and 2461 casings. NIST and ATF are proposing to

Traceability for Ballistics Signature Measurements in Forensic Science

December 1, 2009
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou, Li Ma, Thomas Brian Renegar, Xiaoyu Alan Zheng, Martin Ols
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Casings. NIST has also developed a 2D

NIST SRM (Standard Reference Material) 2460/2461 Standard Bullets and Casings Project

October 13, 2009
Author(s)
Jun-Feng Song, Thomas Brian Renegar, Xiaoyu Alan Zheng, Robert M. Thompson, Richard M. Silver, Martin M. Ols, Ted T. Vorburger
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Cartridge Cases. NIST has also

GEOMETRIC MEASUREMENT COMPARISONS FOR ROCKWELL DIAMOND INDENTERS

September 6, 2009
Author(s)
Jun-Feng Song, Samuel R. Low III, Xiaoyu A. Zheng
In the uncertainty budget of Rockwell C hardness (HRC) tests, geometric error of the Rockwell diamond indenter is a major contributor. The geometric calibration of Rockwell diamond indenters has been a key issue for Rockwell hardness standardization. The

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