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M. Martinez, P. L. De Leon, and D. Keeley, “Bayesian classification of falls risk,” Gait & Posutre, vol. 67, pp. 99-103, Jan. 2019.

 

C.T. Rodenbeck, M. Martinez, J. B. Beun, J. Silva-Martinez, A. Karsilayan and R. Liechty, “When less is more … few bit ADCs in RF systems,” IEEE Access, vol. 7, pp. 12035-12046, Jan. 2019. https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8606934 

M. Martinez and P. L. De Leon, “Falls risk classification of older adults using deep neural networks and transfer learning,” IEEE J. Biomed. and Health Inform., 2019

 J. D. Tucker, L. Shand, and J. R. Lewis, “Handling Missing Data in Self-Exciting Point Process Models,” Spatial Statistics, vol. 29. pp. 160-176, 2019. PDF

J. D. Tucker, J. R. Lewis, and A. Srivastava, “Elastic Functional Principal Component Regression,” Statistical Analysis and Data Mining, vol. 12, no. 2, pp. 101-115, 2019. PDF

Y. Guan, C. Sampson, J. D. Tucker, W. Chang, A. Mondal, M. Haran, and D. Sulsky, “Computer model calibration based on image warping metrics: an application for sea ice deformation,” Journal of Agricultural, Biological and Environmental Statistics, 10.1007/s13253-019-00353-7, 2019 PDF

Variability of Ventricular Repolarization Dispersion Quantified by Time-Warping the Morphology of the T-waves  File Format: PDF/Adobe Acrobat.   Ramirez, M. Orini, J. D. Tucker, P. Laguna, and E. Pueyo, “Variability of Ventricular Repolarization Dispersion Quantified by Time-Warping the Morphology of the T-waves,” IEEE Transactions on Biomedical Engineering, vol 64, no 7, pp 1619-1630, 2017 

Linear Minelayer Trajectory Estimation Using Cluttered Point Cloud Data  File Format: PDF/Adobe Acrobat.  Bryner, F. Huffer, M. M. Rosenthal, J. D. Tucker, and A. Srivastava, “Linear Minelayer Trajectory Estimation Using Cluttered Point Cloud Data,” Computational Statistics and Data Analysis, vol. 102, pp. 1-22, October 2016 

Underwater Mine Detection In Clutter Data Using Spatial Point Process Models File Format: PDF/Adobe Acrobat.  Bryner, F. Huffer, A. Srivastava, and J. D. Tucker, “Underwater Mine Detection In Clutter Data Using Spatial Point Process Models,” IEEE Journal of Oceanic Engineering, vol 41, no. 3. pp 670-681, 2016 

Image-based Automated Change Detection for Synthetic Aperture Sonar File Format: PDF/Adobe Acrobat.  G-Michael, B. Marchand, J. D. Tucker, D. D. Sternlicht, T. M. Marston, and M. R. Azimi-Sadjadi, “Image-based Automated Change Detection for Synthetic Aperture Sonar,” IEEE Journal of Oceanic Engineering, vol 41, no. 3. pp 592-612, 2016. 

Phase-Amplitude Separation of Proteomics Data Using Extended Fisher-Rao Metric  File Format: PDF/Adobe Acrobat.   D. Tucker, W. Wu, and A. Srivastava, “Phase-Amplitude Separation of Proteomics Data Using Extended Fisher-Rao Metric,” Electronic Journal of Statistics, vol 8, no. 2. pp 1724-1733, 2014. [ Code]

Analysis of signals under compositional noise with applications to SONAR data File Format: PDF/Adobe Acrobat.  D. Tucker, W. Wu, and A. Srivastava, “Analysis of signals under compositional noise with applications to SONAR data,” IEEE Journal of Oceanic Engineering, vol 29, no. 2. pp 318-330, Apr 2014. [ Code]

Generative Models for Function Data using Phase and Amplitude Separation File Format: PDF/Adobe Acrobat.  D. Tucker, W. Wu, and A. Srivastava, “Generative Models for Function Data using Phase and Amplitude Separation,” Computational Statistics and Data Analysis, vol. 61, pp. 50-66, May 2013.

Coherence-based underwater target detection from multiple sonar platforms File Format: PDF/Adobe Acrobat.  D. Tuckerand M. R. Azimi-Sadjadi, “Coherence-based underwater target detection from multiple sonar platforms,” IEEE Journal of Oceanic Engineering, vol. 36, no. 1, pp. 37-51, Jan. 2011. 

Selecting an Informative/Discriminating Multivariate Response For Inverse Prediction File Format: PDF/Adobe Acrobat.  Thomas, Edward V., Lewis, John, Christine Anderson-Cook, Thomas Burr, and Michael Hamada, “Selecting an Informative/Discriminating Multivariate Response For Inverse Prediction”. Journal of Quality Technology, vol 49, no 3, pp. 228–243, 2017

xLPR Scenario Analysis Report File Format: PDF/Adobe Acrobat.  Eckert-Gallup, Aubrey C., Lewis, John R., Nevin S. Martin, Lauren B. Hund, Andrew J Clark, Dusty M. Brooks, and Paul E. Mariner (2017). xLPR Scenario Analysis Report. SAND2017-2854, UUR. Albuquerque, New Mexico 87185 and Livermore, California 94550: Sandia National Laboratories

Uncertainty Quantification and Comparison of Weld Residual Stress Measurements and Predictions  File Format: PDF/Adobe Acrobat.  Lewis, John R. and Dusty Brooks (2016). Uncertainty Quantification and Comparison of Weld Residual Stress Measurements and Predictions. SAND2016- 10932, UUR. Albuquerque, New Mexico 87185 and Livermore, California 94550: Sandia National Laboratories (pdf)

A Statistical Perspective on Highly Accelerated Testing
Thomas (2015). File Format: PDF/Adobe Acrobat. Highly accelerated life testing has been heavily promoted at Sandia (and elsewhere) as a means to rapidly identify product weaknesses caused by flaws in the product's design or manufacturing process. During product development, a small number of units are forced to fail at high stress. The …

Robust Design of Reliability Test Plans Using Degradation Measures
Lane | Crowder (2014). File Format: PDF/Adobe Acrobat. With short production development times, there is an increased need to demonstrate product reliability relatively quickly with minimal testing. In such cases there may be few if any observed failures. Thus, it may be difficult to assess reliability using the traditional reliability test plans that…

A Margin Based Approach to Determining Sample Sizes via Tolerance Bounds
Newcomer | Freeland (2013). File Format: PDF/Adobe Acrobat. This paper proposes a tolerance bound approach for determining sample sizes. With this new methodology we begin to think of sample size in the context of uncertainty exceeding margin. As the sample size decreases the uncertainty in the estimate of margin increases…

1 Mil Gold Bond Wire Study
Rutherford (2013). File Format: PDF/Adobe Acrobat. In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold…

Analysis of Signals Under Compositional Noise With Applications to SONAR Data
Tucker (2013). File Format: PDF/Adobe Acrobat. We consider the problem of denoising and classification of SONAR signals observed under compositional noise, i.e., they have been warped randomly along the x-axis. The traditional techniques do not account for such noise and, consequently, cannot provide a robust …

A New Approach to Quantification of Margins and Uncertainties for Physical Simulation Data
Newcomer (2012). File Format: PDF/Adobe Acrobat. This paper proposes the use of statistical tolerance interval methodology as an approach to quantification of margins and uncertainties (QMU) for physical simulation data. We review the standard k-factor methodologies and discuss potential limitations. The tolerance interval methodology is introduced…

Generative Models for Functional Data using Phase and Amplitude Separation
Tucker (2012). File Format: PDF/Adobe Acrobat. Constructing generative models for functional observations is an important task in statistical functional analysis. In general, functional data contains both phase (or x or horizontal) and amplitude (or y or vertical) variability. Traditional methods often ignore the phase …

Coherence-Based Underwater Target Detection From Multiple Disparate Sonar Platforms
Tucker (2011). File Format: PDF/Adobe Acrobat. This paper explores the use of multichannel coherence as a tool for detection of underwater targets from imagery captured from multiple disparate sonar systems. The use of multiple disparate sonars allows one to exploit a high-resolution sonar with good …

Modeling Injection Molding of Net-Shape Active Ceramic Components
Halbleib (2006). File Format: PDF/Adobe Acrobat. To reduce costs and hazardous wastes associated with the production of lead-based active ceramic components, an injection molding process is being investigated to replace the current machining process. Here, lead zirconate titanate (PZT) ceramic particles are suspended in a…

LEADERSHIP DEVELOPMENT STUDY: Success Profile Competencies and High-Performing Leaders at Sandia National Laboratories
Crowder (2005). File Format: PDF/Adobe Acrobat. Sandia is undergoing tremendous change. Sandia’s executive management recognized the need for leadership development. About ten years ago the Business, Leadership, and Management Development department in partnership with executive management developed…

The Effects of Process Parameters on Injection-Molded PZT Ceramics Part Fabrication- Compounding Process Rheology
Halbleib (2005). File Format: PDF/Adobe Acrobat. Solid solutions of lead-based perovskites are the backbone materials of the piezoelectric components for transducer, actuator, and resonator applications. These components, typically small in size, are fabricated from large sintered ceramic slugs using grinding and lapping…

Case Study for Model Validation: Assessing a Model for Thermal Decomposition of Polyurethane Foam
Rutherford (2004). File Format: PDF/Adobe Acrobat. A case study is reported to document the details of a validation process to assess the accuracy of a mathematical model to represent experiments involving thermal decomposition of polyurethane foam. The focus of the report is to work through a validation process. The process addresses…

Experimental Design and Analysis for Accelerated Degradation Tests with Li-Ion Cells
Thomas (2003). File Format: PDF/Adobe Acrobat. This document describes a general protocol (involving both experimental and data analytic aspects) that is designed to be a roadmap for rapidly obtaining a useful assessment of the average lifetime (at some specified use conditions) that might be expected from cells of a particular design. The…

Characterization of the Precision Laser Beam Welding Process for the MC4368A Neutron Generator
Crowder (2001). File Format: PDF/Adobe Acrobat. The design of experiments (DOEx) approach was used to characterize the Precision Laser Beam Welding Process with respect to four processing factors: Angle of Attack, Volts, Pulse Length, and Focus. The experiment was performed with Lap Joints, Nickel-Wire Joints, and…

Approximate Public Key Authentication with Information Hiding
Thomas (2000). File Format: PDF/Adobe Acrobat. This paper describes a solution for the problem of authenticating the shapes of statistically variant gamma spectra while simultaneously concealing the shapes and magnitudes of the sensitive spectra. The shape of a spectrum is given by the relative magnitudes and positions of the individual…

Small Sample Experimental Design Optimization and Repair
Crowder (1999). File Format: PDF/Adobe Acrobat. The primary goal of using Design of Experiment (DOEx) methods is to extract the maximum amount of information concerning experimental factors and their interactions from as few observations as possible. DOEx methodology allows an experimenter to selectively and systematically…

Small Sample Properties of an Adaptive Filter with Application to Low Volume Statistical Process Control
Crowder (1998). File Format: PDF/Adobe Acrobat. In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards while building much smaller lot sizes…

Advanced Materials for Aerospace and Biomedical Applications: New Glasses for Hermetic Titanium Seals
Crowder (1996). File Format: PDF/Adobe Acrobat. Titanium and titanium alloys have an outstanding strength-to-weight ratio and corrosion resistance and so are materials of choice for a variety of aerospace and biomedical applications. Such applications are limited by the lack of a viable hermetic glass sealing technology. Conventional silicate…

Development of the Nuclear Weapons Complex EP Architecture
Halbleib (1996). File Format: PDF/Adobe Acrobat. The Nuclear Weapons Guidance Team is an interagency committee led by Earl Whiteman, DOE that chartered the generation of EP40100, Concurrent Qualification and its successor EP 401099, Concurrent Engineering and Qualification. As this new philosophy of concurrent operations has…

Defense Programs Business Practices Re-engineering QFD Exercise
Halbleib (1996). File Format: PDF/Adobe Acrobat. The end of the cold war has resulted in many changes for the Nuclear Weapons Complex (NWC). We now work in a smaller complex with reduced resources, a smaller stockpile, and no new phase 3 weapons development programs. This new environment demands that we re-evaluate the…

Extraction of Information from Unstructured Text
Crowder (1995). File Format: PDF/Adobe Acrobat. Extracting information from unstructured text has become an emphasis in recent years due to the large amount of text now electronically available. This status report describes the findings and work done by the end of the first year of a two-year LDRD. Requirements of the approach…

Simultaneous Inference in Multivariate Calibration
Thomas (1994). File Format: PDF/Adobe Acrobat. A set of q responses, y = ( y1, y2, ....., yq)T, is related to a set of p explanatory variables, x = (x1, x2, ...., xp)T, through the classical linear model, yT = a + xTB + eT. The parameters, a and B, are estimated during calibration using a training set. The fitted calibration model that follows is then used…

Evaluating the Ignition Sensitivity of Thermal Battery Heat Pellets
Thomas (1993). File Format: PDF/Adobe Acrobat. Thermal batteries are activated by the ignition of heat pellets. If the heat pellets are not sensitive enough to the ignition stimulus, the thermal battery will not activate, resulting in a dud. Thus, to assure reliable thermal batteries, it is important to demonstrate that the pellets have satisfactory ignition sensitivity…

Improvement of the Stability of the Process for Synthesizing Chemically Prepared Varistor Powder
Thomas (1992). File Format: PDF/Adobe Acrobat. High field varistors are utilized as voltage regulators in neutron generators. Varistor material is currently supplied by a single, proprietary commercial source. The chem-prep varistor process was developed as a backup/replacement for that source. With the transfer of the chem-prep process…

Statistical Process Control for Charting Multiple Sources of Variation With an Application to Neutron Tube Production
Crowder (1990). File Format: PDF/Adobe Acrobat. Multiple sources of variation will often affect the stability of a manufacturing process. Items from different batches may vary because of variation both within a batch and among different batches. Potential sources of variation include within run, run-to-run and week-to-week differences…

Deformation Study of Separator Pellets for Thermal Batteries
Thomas (1990). File Format: PDF/Adobe Acrobat. The deformation characteristics of pellets of electrolyte-binder (EB) mixes based on MgO were measured under simulated, thermal-battery conditions. Measurements (using a statistically designed experimental strategy) were made as a function of applied pressure, temperature, and percentage of…

An Evaluation of the Effects of Varying Composition and Processing on Several Encapsulating Resins
Thomas (1989). File Format: PDF/Adobe Acrobat. This investigation describes how a statistically designed experiment can be useful to characterize the relationship between a fundamental material property such as the glass transition temperature, Tg, and various processing parameters, e.g. composition, cure time, and temperature...

Final Report of Lithium Ambient Temperature Battery Reliability
Thomas (1987). File Format: PDF/Adobe Acrobat. A program to develop nondestructive testing techniques to enable prediction of the reliability of primary lithium cells has been underway since FY 1981. Various candidate techniques, such as microcalorimetry and complex impedance analysis were considered and tried. Statistical analysis of available…

S-Glass Analysis by X-Ray Spectroscopy
Thomas (1987). File Format: PDF/Adobe Acrobat. A rapid and accurate x-ray fluorescence (XRF) method for estimating concentrations of K2O, SiO2, Al2O3, P2O5, and (Li2O + B2O3) in S-glass was developed based on the use of a fundamental parameters program, a set of secondary S-glass standards, and an iterative adjustment of Li2O and/or…

LOWER CONFIDENCE BOUNDS ON SYSTEM RELIABILITY USING COMPONENT DATA
Spencer | Easterling (1986). File Format: PDF/Adobe Acrobat. The "Maximus methodology" of calculating approximate lower confidence bounds on system reliability, based upon binomial component data, is presented. This method was developed by an Ad Hoc Methodology Working Group on Nuclear Weapons Reliability Assessment, which was…

A Sample Preselection Process Designed to Enhance Early Planning Information
Müller | Spencer (1981). File Format: PDF/Adobe Acrobat. The DOE provides for the continuing evaluation of the nuclear weapon stockpiles through a stockpile sampling program in which randomly selected weapons are withdrawn for testing from the stockpiles each year. For some time, DOE has used a preselection scheme to obtain early…