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Search Publications by: Theodore V. Vorburger (Assoc)

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Displaying 1 - 25 of 417

Evaluating Measurement Uncertainty for Firearm Barrel and Overall Length Measurements

November 1, 2021
Author(s)
Michael Stocker, Theodore V. Vorburger, Thomas Renegar, Robert Thompson, Mark Williford
In recent years, more forensic laboratories are seeking accreditation to ISO 17020 and 17025. In the field of firearm and toolmark forensics, the barrel length and overall length of a firearm are typical measurements performed in the laboratory to

Emerging Technology in Comparisons

March 1, 2019
Author(s)
Theodore V. Vorburger, Jun-Feng Song, Nicholas D. Petraco, Ryan Lilien
This chapter is designed to introduce the reader to emerging technologies relating to 3D surface topography measurement and comparative analysis. While the chapter includes several technical terms and a few equations, effort has been made to omit content

Estimating Error Rates for Firearm Evidence Identifications in Forensic Science

March 1, 2018
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Wei Chu, James H. Yen, Johannes A. Soons, D Ott, Nien F. Zhang
Estimating error rates for firearm evidence identification is a fundamental challenge in forensic science. This paper describes the recently developed Congruent Matching Cells (CMC) method for image comparisons, its application to firearm identification

Evaluation of Carbon Nanotube Probes in Critical Dimension Atomic Force Microscopes

August 26, 2016
Author(s)
Jinho Choi, Byong Chon Park, Sang Jung Ahn, Dal-Hyun Kim, J Lyou, Ronald G. Dixson, Ndubuisi George Orji, Joseph Fu, Theodore V. Vorburger
The decreasing size of semiconductor features and the increasing structural complexity of advanced devices has placed continuously greater demands on manufacturing metrology-arising both from the measurement challenges of smaller feature sizes and the

Topography measurements and applications in ballistics and tool mark identifications

December 17, 2015
Author(s)
Theodore V. Vorburger, Jun-Feng Song, Nicholas D. Petraco
The application of surface topography measurement methods to the field of firearm and toolmark analysis is fairly new. The field has been boosted by the development of a number of competing optical methods which has improved the speed and accuracy of

The Second National Ballistics Imaging Comparison (NBIC-2)

January 5, 2015
Author(s)
Theodore V. Vorburger, James H. Yen, Jun-Feng Song, Robert M. Thompson, Thomas Brian Renegar, Xiaoyu Alan Zheng, D Ott, Martin G. Ols
In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, NIST and the ATF initiated a

Applications of Surface Metrology in Firearm 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. Toolmarks are created when a tool comes into contact with a surface and causes

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

Distributed Force Probe Bending Model of CD-AFM Bias

April 1, 2013
Author(s)
Vladimir A. Ukraintsev, Ndubuisi George Orji, Theodore V. Vorburger, Ronald G. Dixson, Joseph Fu, Richard M. Silver
Critical Dimension AFM (CD-AFM) is a widely used reference metrology technique. To characterize modern semiconductor devices, small and flexible probes, often 15 nm to 20 nm in diameter, are used. Recent studies have reported uncontrolled and significant