DATAWorks Sessions Archive

An overview of Deep Reinforcement Learning and it’s recent successes in creating high performing agents. Covering it’s application in “easy” environments up to massively complex multi-agent strategic environments. Will analyze the behaviors learned, discuss research challenges, and imagine future possibilities.

Collaborative autonomous sensor networks have recently been used in many applications including inspection, law enforcement, search and rescue, and national security. They offer scalable, low cost solutions which are robust to the loss of multiple sensors in hostile or dangerous environments. While often comprised of less capable sensors, the performance of a large network can approach the performance of far more capable and expensive platforms if nodes are effectively coordinating their sensing actions and data processing. This talk will summarize work to date at LLNL on distributed signal processing and decentralized optimization algorithms for collaborative autonomous sensor networks, focusing on ADMM-based solutions for detection/estimation problems and sequential greedy optimization solutions which maximize submodular functions, e.g. mutual information.

Cyber system defenders face the challenging task of continually protecting critical assets and information from a variety of malicious attackers. Defenders typically function within resource constraints, while attackers operate at relatively low costs. As a result, design and development of resilient cyber systems that support mission goals under attack, while accounting for the dynamics between attackers and defenders, is an important research problem. This talk will highlight decision support modeling challenges under uncertainty within non-cooperative cybersecurity settings. Multiple attacker-defender game formulations under uncertainty are discussed with steps for further research.

Software reliability models enable several quantitative predictions such as the number of faults remaining, failure rate, and reliability (probability of failure free operation for a specified period of time in a specified environment). This talk will describe recent efforts in collaboration with NASA, including (1) the development of an automated script for the SFRAT (Software Failure and Reliability Assessment Tool) to streamline application of software reliability methods to ongoing programs, (2) application to a NASA program, (3) lessons learned, (4) and future directions for model and tool development to support the practical needs of the software reliability and security assessment frameworks.

The U.S. Army Research Laboratory’s (ARL) Essential Research Program (ERP) on Artificial Intelligence & Machine Learning (AI & ML) seeks to research, develop and employ a suite of AI-inspired and ML techniques and systems to assist teams of soldiers and autonomous agents in dynamic, uncertain, complex operational conditions. Systems will be robust, scalable, and capable of learning and acting with varying levels of autonomy, to become integral components of networked sensors, knowledge bases, autonomous agents, and human teams. Three specific research gaps will be examined: (i) Learning in Complex Data Environments, (ii) Resource-constrained AI Processing at the Point-of-Need and (iii) Generalizable & Predictable AI. The talk will highlight ARL’s internal research efforts over the next 3-5 years that are connected, cumulative and converging to produce tactically-sensible AI-enabled capabilities for decision making at the tactical edge, specifically addressing topics in: (1) adversarial distributed machine learning, (2) robust inference & machine learning over heterogeneous sources, (3) adversarial reasoning integrating learned information, (4) adaptive online learning and (5) resource-constrained adaptive computing. The talk will also highlight collaborative research opportunities in AI & ML via ARL’s Army AI Innovation Institute (A2I2) which will harness the distributed research enterprise via the ARL Open Campus & Regional Campus initiatives.

“The wise use of one’s resources will keep one from poverty.” This is the definition of the proverbial saying “waste not, want not” according to www.dictionary.com. Indeed, one of the most common resources analysts encounter is text in free-form. This text might come from survey comments, feedback, websites, transcriptions of interviews, videos, etcetera. Notably, researchers have used wisely the information conveyed in text for many years. However, in many instances, the qualitative methods employed require numerous hours of reading, training, coding, and validating, among others. As technology continues to evolve, simple access to text data is blooming. For example, analysts conducting online studies can have thousands of text entries from participants’ comments. Even without recent advances in technology analysts have had access to text in books, letters, and other archival data for centuries. One important challenge, however, is figuring out how to make sense of text data without investing a large number of resources, time, and the effort involved in qualitative methodology or “old-school” quantitative approaches (such as reading a collection of 200 books and counting the occurrence of important terms in the text). This challenge has been solved in the information retrieval field –a branch of computer science—with the implementation of a technique called latent semantic analysis (LSA; Manning, Raghavan, & Schütze, 2008) and a closely related technique called topic analysis (TA; SAS Institute Inc., 2018). Undoubtedly, other quantitative methods for text analysis, such as latent Dirichlet analysis (Blei, Ng, & Jordan, 2003), are also apt for the task of unveiling knowledge from text data, but we restrict the discussion in this presentation to LSA and TA because these exclusively deal with the underlying structure of the text rather than identifying clusters. In this presentation, we aim to make quantitative text analysis –specifically LSA and TA– accessible to researchers and analysts from a variety of disciplines. We do this by leveraging understanding of a popular multivariate technique: principal components analysis (PCA). We start by describing LSA and TA by drawing comparisons and equivalencies to PCA. We make these comparisons in an intuitive, user-friendly manner and then through a technical description of mathematical statements, which rely on the singular value decomposition of a document-term matrix. Moreover, we explain the implementation of LSA and TA using statistical software to enable simple application of these techniques. Finally, we show a practical application of LSA and TA with empirical data of aircraft incidents.

Sensors that record sequences of measurements are now embedded in many products from wearable exercise watches to chemical and semiconductor manufacturing equipment. There is information in the shapes of the sensor stream curves that is highly predictive of a variety of outcomes such as the likelihood of a product failure event or batch yield. Despite this data now being common and readily available, it is often being used either inefficiently or not at all due to lack of knowledge and tools for how to properly leverage it. In this presentation, we will propose fitting splines to sensor streams and extracting features called functional principal component scores that offer a highly efficient low dimensional compression of the signal data. Then, we use these features as inputs into machine learning models like neural networks and LASSO regression models. Once one sees sensor data in this light, answering a wide variety of applied questions becomes a straightforward two stage process of data cleanup/functional feature extraction followed by modeling using those features as inputs.

Abstract: In applications where modeling and simulation runs are quick and cheap, space filling designs will give the tester all the information they need to make decisions about their system. In some applications however, this luxury does not exist, and each M&S run can be time consuming and expensive. In these scenarios, a sequential test approach provides an efficient solution where an initial screening is conducted, followed by an augmentation to fit specified models of interest. Until this point, no dedicated screening designs for UQ applications in resource constrained situations existed. Due to the Army’s frequent exposure to this type of situation, the need sparked a collaboration between Picatinny’s Statistical Methods and Analysis group and Professor V. Roshan Joseph of Georgie Tech, where a new type of UQ screening design was created. This paper provides a brief introduction to the design, its intended use, and a case study in which this new methodology was applied.

Whether it was in a Design of Experiments course or through your own work, you’ve no doubt seen and become well acquainted with the standard experimental design. You know the features: they’re “orthogonal” (no messy correlations to deal with), their correlation matrices are nice pretty diagonals, and they can only happen with run sizes of 4, 8, 12, 16, and so on. Well what if I told you that there existed optimal designs that defied convention. What if I told you that, yes, you can run an optimal design with, say, 5 factors in 9 runs. Or 10. Or even 11 runs! Join me as I show you a strange new world of optimal designs that are the best at what they do, even though they might not look very nice.

During the past several years, the DoD has begun applying rapid prototyping and fielding authorities—granted by Congress in the FY2016-FY2018 National Defense Authorization Acts (NDAA)—to many acquisition programs. Other programs have implemented an agile acquisition strategy where incremental capability is delivered in iterative cycles. As a result, Operational Test Agencies (OTA) have had to adjust their test processes to accommodate shorter test timelines and periodic delivery of capability to the warfighter. In this session, representatives from the Service OTAs will brief examples where they have implemented new practices and processes for conducting Operational Test on acquisition programs categorized as agile, DevOps, and/or Section 804 rapid-acquisition efforts. During the final 30 minutes of the session, a panel of OTA representatives will field questions from the audience concerning the challenges and opportunities related to test design, data collection, and analysis, that rapid-acquisition programs present.

NASA is investigating the dose-response relationship between quiet sonic boom exposure and community noise perceptions. This relationship is the key to possible future regulations that would replace the ban on commercial supersonic flights with a noise limit. We have built several Bayesian statistical models using pilot community study data. Using goodness of fit measures, we downselected to a subset of models which are the most appropriate for the data. From this subset of models we demonstrate how to calculate sample size requirements for a simplified example without any missing data. We also suggest how to modify the sample size calculation to account for missing data.

Swarms of small, fast speedboats can challenge even the most capable modern warships, especially when they operate in or near crowded shipping lanes. As part of the Navy’s operational testing of new ships and systems, at-sea live-fire tests against remote-controlled targets allow us to test our capability against these threats. To ensure operational realism, these events are minimally scripted and allow the crew to respond in accordance with their training. This is a trade-off against designed experiments, which ensure statistically optimal sampling of data from across the factor space, but introduce many artificialities. A recent test provided data on the effectiveness of naval gunnery. However, standard binomial (hit/miss) analyses fell short, as the number of misses was much larger than the number of hits. This prevented us from fitting more than a few factors and resulted in error bars so large as to be almost useless. In short, binomial analysis taught us nothing we did not already know. Recasting gunfire data from binomial (hit/miss) to continuous (time-to-kill) allowed us to draw statistical conclusions with tactical implications from these free-play, live-fire surface gunnery events. Using a censored-data analysis approach enabled us to make this switch and avoid the shortcomings of other statistical methods. Ultimately, our analysis provided the Navy with suggestions for improvements to its tactics and the employment of its weapons.

Recent data from Boeing’s Statistical Summary of Commercial Jet Airplane Accidents shows that Loss of Control – In Flight (LOC-I) is the leading cause of fatalities in commercial aviation accidents worldwide. The Commercial Aviation Safety Team (CAST), a joint government and industry effort tasked with reducing the rate of fatal accidents, requested that the National Aeronautics and Space Administration (NASA) conduct research on virtual day-visual meteorological conditions displays, such as synthetic vision, in order to combat LOC-I. NASA recently concluded a series of experiments using commercial pilots from various backgrounds to evaluate synthetic vision displays. This presentation will focus on the two most recent experiments: one conducted with the Navy’s Disorientation Research Device and one completed at NASA Langley Research Center that utilized the Microsoft HoloLens to display synthetic vision. Statistical analysis was done on aircraft performance data, pilot inputs, and a range of subjective questionnaires to assess the efficacy of the displays.

This presentation will use a notional armament system case-study to illustrate the use of M&S DOE, surrogate modeling, sensitivity analysis, multi-objective optimization and model calibration during early lifecycle development and design activities in the context of a new armament system. In addition to focusing on the statistician’s, data scientist’s, or analyst’s role and the key statistical techniques in engineering DoD systems, this presentation will also emphasize the non-statistical / engineering domain-specific aspects in a multidisciplinary design and development process which make uses of these statistical approaches at the subcomponent and subsystem-level as well as the end-to-end system modeling. A statistical engineering methodology which emphasizes the use of ‘virtual’ DOE-based model emulators developed at the subsystem-level and integrated using a systems-engineering architecture framework can yield a more tractable engineering problem compared to traditional ‘design-build-test-fix’ cycles or direct simulation of computationally expensive models. This supports a more informed prototype design for physical experimentation while providing a greater variety of materiel solutions thereby reducing development and testing cycles and time to field complex systems.

Combining physical measurements with computational models is key to many investigations involving validation and uncertainty quantification (UQ). This talk surveys some of the many approaches taken for validation and UQ, with large-scale computational models. Experience with such applications suggests classifications of different types of problems with common features (e.g. data size, amount of empiricism in the model, computational demands, availability of data, extent of extrapolation required, etc.). More recently, social and social-technical systems are being considered for similar analyses, bringing new challenges to this area. This talk will approaches for such problems and will highlight what might be new research directions for application and methodological development in UQ.

This case study highlights activities performed during the front-end process of a software development effort undertaken by the Fire Support Command and Control Program Office. This program office provides the U.S. Army, Joint and coalition commanders with the capability to plan, execute and deliver both lethal and non-lethal fires. Recently, the program office has undertaken modernization of its primary field artillery command and control system that has been in use for over 30 years. The focus of this case study is on the user-centered design process and activities taken prior to and immediately following contract award. A modified waterfall model comprised of three cyclic, yet overlapping phases (observation, visualization, and evaluation) provided structure for the iterative, user-centered design process. Gathering and analyzing data collected during focus groups, observational studies, and workflow process mapping, enabled the design team to identify 1) design patterns across the role/duty, unit and echelon matrix (a hierarchical organization structure), 2) opportunities to automate manual processes, 3) opportunities to increase efficiencies for fire mission processing, 4) bottlenecks and workarounds to be eliminated through design of the modernized system, 5) shortcuts that can be leveraged in design, 6) relevant and irrelevant content for each user population for streamlining access to functionality, 7) a usability baseline for later comparison (e.g., the number of steps and time taken to perform a task as captured in workflows for comparison to the same task in the modernized system), and provided the basis for creating visualizations using wireframes. Heuristic evaluations were conducted early to obtain initial feedback from users. In the next few months, usability studies will enable users to provide feedback based on actual interaction with the newly designed software. Included in this case study are descriptions of the methods used to collect user-centered design data, how results were visualized/documented for use by the development team, and lessons learned from applying user-centered design techniques during software development of a military field artillery command and control system.

Due to the immense potential use cases, configurations, and threat behaviors, thorough and efficient cyber testing is a significant challenge for the defense community. In this presentation, Phadke will present case studies where STO was successfully deployed for cyber testing, resulting in higher assurance, reduced schedule, and reduced testing cost. Phadke will also discuss importance first focusing on the engineering and science analysis, and only after that is complete, implementing statistical methods.

Advances in high performance computing have enabled detailed simulations of real-world physical processes, and these simulations produce large datasets. Even as detailed as they are, these simulations are only approximations of imperfect mathematical models, and furthermore, their outputs depend on inputs that are themselves uncertain. The main goal of a validation and uncertainty quantication methodology is to determine the uncertainty, that is, the relationship between the true value of a quantity of interest and its prediction by the simulation. The value of the computational results is limited unless the uncertainty can be quantied or bounded. Bayesian calibration is a common method for estimating model parameters and quantifying their associated uncertainties; however, calibration becomes more complicated when the data arise from dierent types of experiments. On an example from material science we will employ two types of data and demonstrate how one can obtain a set of material strength models that agree with both data sources.

Communication is critical both for analysts and decision-makers who rely on analysis to inform their choices. The Service Academies are responsible for educating men and women who may serve in both roles over the course of their careers. Analysts must be able to summarize their results concisely and communicate them to the decision-maker in a way that is relevant and actionable. Decision-makers understand that analytical results may carry with them uncertainty and be able to incorporate this uncertainty properly when evaluating different options. This panel explores the role of the US Service Academies in preparing their students for both roles. Featuring representatives from the US Air Force Academy, the US Naval Academy, and the US Military Academy, this panel will cover how future US Officers are taught to use and communicate with data. Topics include developing and motivating numerical literacy, understandings of uncertainty, how analysts should frame uncertainty to decision-makers, and how decision-makers should understand information presented with uncertainty. Panelists will discuss what they think the academies do well and areas that are ripe for improvement.

This talk focuses on a means to characterize the variability in multivariate data. This characterization, given in terms of both probability distributions and closed sets, is instrumental in assessing and improving the robustness/reliability properties of system designs. To this end, we propose the Sliced-Normal (SN) class of distributions. The versatility of SNs enables modeling complex multivariate dependencies with minimal modeling effort. A polynomial mapping is defined which injects the physical space into a higher dimensional (so-called) feature space on which a suitable normal distribution is defined. Optimization-based strategies for the estimation of SNs from data in both physical and feature space are proposed. The formulations in physical space yield non-convex optimization programs whose solutions often outperform the solutions in feature space. However, the formulations in feature space yield either an analytical solution or a convex program thereby facilitating their application to problems in high dimensions. The superlevel sets of a SN density have a closed semi-algebraic form making them amenable to rigorous uncertainty quantification methods. Furthermore, we propose a chance-constrained optimization framework for identifying and eliminating the effects of outliers in the prescription of such regions. These strategies can be used to mitigate the conservatism intrinsic to many methods in system identification, fault detection, robustness/reliability analysis, and robust design caused by assuming parameter independence and by including outliers in the dataset.

Uncertainty quantification (UQ) has emerged as the science of quantitative characterization and reduction of uncertainties in simulation and testing. Stretching across applied mathematics, statistics, and engineering, UQ is a multidisciplinary field with broad applications. A popular UQ method to analyze the effects of input variability and uncertainty on the system responses is generalized Polynomial Chaos Expansion (gPCE). This method was developed using applied mathematics and does not require knowledge of a simulation’s physics. Thus, gPCE may be used across disparate industries and is applicable to both individual component and system level simulations. The gPCE method can encounter problems when any of the input configurations fail to produce valid simulation results. gPCE requires that results be collected on a sparse grid Design of Experiment (DOE), which is generated based on probability distributions of the input variables. A failure to run the simulation at any one input configuration can result in a large decrease in the accuracy of a gPCE. In practice, simulation data sets with missing values are common because simulations regularly yield invalid results due to physical restrictions or numerical instability. We propose a statistical approach to mitigating the cost of missing values. This approach yields accurate UQ results if simulation failure makes gPCE methods unreliable. The proposed approach addresses this missing data problem by introducing an iterative machine learning algorithm. This methodology allows gPCE modelling to handle missing values in the sparse grid DOE. The study will demonstrate the convergence characteristics of the methodology to reach steady state values for the missing points using a series of simulations and numerical results. Remarks about the convergence rate and the advantages and feasibility of the proposed methodology will be provided. Several examples are used to demonstrate the proposed framework and its utility including a secondary air system example from the jet engine industry and several non-linear test functions. This is based on joint work with Dr. Mark Andrews at SmartUQ.

One of the primary roles of navy surface combatants is defending high-value units against attack by anti-ship cruise missiles (ASCMs). They accomplish this either by launching their interceptor missiles and shooting the ASCMs down with rapid-firing guns (hard kill), or through the use of deceptive jamming, decoys, or other non-kinetic means (soft kill) to defeat the threat. The wide range of hostile ASCM capabilities and the different properties of friendly defenses, combined with the short time-scale for defeating these ASCMs, makes this a difficult problem to study. IDA recently completed a study focusing on the extent to which friendly forces were vulnerable to massed ASCM attacks, and possible avenues for improvement. To do this we created a pair of complementary models with the combined flexibility to explore a wide range of questions. The first model employed a set of closed-form equations, and the second a time-dependent Monte Carlo simulation. This presentation discusses the thought processes behind the models and their relative strengths and weaknesses.

The concept of sequential testing has many disparate meanings. Often, for statisticians it takes on a purely mathematical context while possibly meaning multiple disconnected test events for some practitioners. Here we present a pedagogical approach to creating test designs involving constrained factors using JMP software. Recent experiences testing one of the U.S. military’s fast jet life support systems (LSS) serves as a case study and back drop to support the presentation. The case study discusses several lessons learned during LSS testing, applicable to all practitioners of scientific test and analysis techniques (STAT) and design of experiments (DOE). We conduct a short analysis to specifically determine a test region with a set of factors pertinent to modeling human breathing and the use of breathing machines as part of the laboratory setup. A comparison of several government and industry laboratory test points and regions with governing documentation is made, along with the our proposal for determining a necessary and sufficient test region for tests involving human breathing as a factor.

A challenging aspect of a system reliability assessment is integrating multiple sources of information, including component, subsystem, and full-system data, previous test data, or subject matter expert opinion. A powerful feature of Bayesian analyses is the ability to combine these multiple sources of data and variability in an informed way to perform statistical inference. This feature is particularly valuable in assessing system reliability where testing is limited and only a small number (or no failures at all) are observed. The F-35 is DoD’s largest program; approximately one-third of the operations and sustainment cost is attributed to the cost of spare parts and the removal, replacement, and repair of components. The failure rate of those components is the driving parameter for a significant portion of the sustainment cost, and yet for many of these components, poor estimates of the failure rate exist. For many programs, the contractor produces estimates of component failure rates, based on engineering analysis and legacy systems with similar parts. While these are useful, the actual removal rates can provide a more accurate estimate of the removal and replacement rates the program anticipates to experience in future years. In this presentation, we show how we applied a Bayesian analysis to combine the engineering reliability estimates with the actual failure data to overcome the problems of cases where few data exist. Our technique is broadly applicable to any program where multiple sources of reliability information need be combined for the best estimation of component failure rates and ultimately sustainment costs.

Sensors abound in aerospace testing and while many scientists look at the data from a physics perspective, the comparative statistics information is what drives decisions. A multi-company project was comparing launch data from the 1980’s to a current set of data that included 30 sensors. Each sensor was designed to gather 3000 data points during the 3-second launch event. The data included temperature, acceleration, and pressure information. This talk will compare the data analysis methods developed for this project as well as the use of the new Functional Data Analysis tool within JMP for its ability to discern in-family launch performances.