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Displaying 26 - 50 of 66

On-Line Process Control

October 16, 2008
Author(s)
Raghu N. Kacker, Nien-Fan Zhang
The natural state of manufacturing and measurement processes is usually nonstationary. The methods of statistical process control (SPC) are therefore inappropriate for on-line control. This paper provides a simple and generic protocol for on-line control

SRM 1955, Homocysteine and Folate in Human Serum; Production of a New Standard Reference Material

October 16, 2008
Author(s)
Mary B. Satterfield, B C. Nelson, Lorna T. Sniegoski, Adriana Hornikova, Nien-Fan Zhang, Christine M. Pfeiffer, Michael J. Welch
Homocysteine (HCY) and folate are interrelated biomarkers for arteriosclerosis and coronary heart disease with health problems associated with increased levels of homocysteine and low levels of folate. Although many different tests for both HCY and folate

Statistical Analysis on Uncertainty for Autocorrelated Measurements

October 16, 2008
Author(s)
Nien-Fan Zhang
When repeated measurements are autocorrelated, it is inappropriate to use the traditional approach to calculate the uncertainty of the average of the measurements, which assumes that the measurements are statistically independent. In this paper, we propose

Allan Variance of Time Series Models of Measurement Data

September 22, 2008
Author(s)
Nien F. Zhang
The uncertainty of the mean of autocorrelated measurements from a stationary process has been discussed in the literature. However, when the measurements are from a non-stationary process, how to assess their uncertainty remains unresolved. Allan variance

Does the Angle of a Fingerprint Scanner Affect User Performance?

September 22, 2008
Author(s)
Mary F. Theofanos, Ross J. Micheals, Shahram Orandi, Brian C. Stanton, Nien F. Zhang, Charles L. Sheppard
As the deployment of biometric technologies such as fingerprints has become more widespread in government applications there is an increased awareness of the human-computer interaction that such technologies involve. User behavior can impact operational

How the User can Improve Fingerprint Image Quality

May 12, 2008
Author(s)
Mary F. Theofanos, Ross J. Micheals, Shahram Orandi, Brian C. Stanton, Nien F. Zhang
Traditionally the biometric field has viewed the user as a passive source of the biometric sample rather than an interactive component of the biometric system. But fingerprint image quality is highly dependent on the human computer interaction and

Usability Testing of Height and Angles of Ten-Print Fingerprint Capture

May 11, 2008
Author(s)
Mary F. Theofanos, Brian C. Stanton, Charles L. Sheppard, Ross J. Micheals, John W. Wydler II, Nien F. Zhang, Lawrence Nadel, William Rubin
As the deployment of biometric technologies such as fingerprints has become more widespread in government applications there is an increased awareness of the human-computer interaction that such technologies involve. User behavior can impact operational

Usability Testing of Ten-Print Fingerprint Capture

October 8, 2007
Author(s)
Brian C. Stanton, Mary F. Theofanos, Shahram Orandi, Ross J. Micheals, Nien F. Zhang
Despite the increased deployment of biometric technologies in United States government applications, not enough attention is being paid to the human factors that such technologies involve. The use of biometric applications will be unfamiliar to many users

Effects of Scanner Height on Fingerprint Capture

June 27, 2007
Author(s)
Mary Theofanos, Shahram Orandi, Ross J. Micheals, Brian Stanton, Nien F. Zhang
Although there is widespread deployment of biometric technologies such as fingerprint systems, little attention is being paid to the human-computer interaction that such technologies involved. This report presents the results of a study that examined the

Usability Testing of Ten-Print Fingerprint Capture

March 13, 2007
Author(s)
Mary Theofanos, Brian Stanton, Shahram Orandi, Ross J. Micheals, Nien F. Zhang
The Department of Homeland Security (DHS) and the United States Visitor and Immigrant Status Indicator Technology (US-VISIT) program are migrating from a two print capture process (left and right index fingers) to a ten-print slap fingerprint capture

Uncertainty Analysis for Virtual Cement Measurement

September 13, 2006
Author(s)
Blaza Toman, Adriana Hornikova, Robert C. Hagwood, Hung-Kung Liu, Nien F. Zhang, Edward J. Garboczi, Jeffrey W. Bullard
Virtual measurements are the outputs of well-defined mathematical models based on theoretical principles and simulation algorithms. The VCCTL (Virtual Cement and Concrete Testing Laboratory) is a software system built by the Material and Construction

Analysis of Sensitivity of VCCTL Measurements to Various Input Quantities

August 9, 2006
Author(s)
Adriana Hornikova, Blaza Toman, Nien F. Zhang, Hung-Kung Liu, Robert C. Hagwood, Edward J. Garboczi, Jeffrey W. Bullard
Virtual measurements are the outputs of well-defined mathematical models based on theoretical principles and simulation algorithms. The VCCTL (Virtual Cement and Concrete Testing Laboratory) is a software system built by the Material and Construction

Statistical Analysis of Key Comparisons with Linear Trends

August 1, 2004
Author(s)
Nien F. Zhang, Hung-Kung Liu, N Sedransk, W Strawderman
A statistical analysis for Key Comparisons with linear trend is proposed. The approach has the advantage that it is consistent with the case in which there is no trend. The uncertainties for KCRV and the degrees of equivalence are also provided. As an

Serial Correlation of QC Data on the Use of Proper Control Charts

May 1, 2004
Author(s)
P Winkel, Nien F. Zhang
Biochemical quality control data have been reported to be autocorrelated. Serial correlation may increase the rate of false alarms and decrease that of true alarms if traditional control charts are used. In this paper, the times series were examined and