125 research outputs found

    Uncertainty and Error in Combat Modeling, Simulation, and Analysis

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    Due to the infrequent and competitive nature of combat, several challenges present themselves when developing a predictive simulation. First, there is limited data with which to validate such analysis tools. Secondly, there are many aspects of combat modeling that are highly uncertain and not knowable. This research develops a comprehensive set of techniques for the treatment of uncertainty and error in combat modeling and simulation analysis. First, Evidence Theory is demonstrated as a framework for representing epistemic uncertainty in combat modeling output. Next, a novel method for sensitivity analysis of uncertainty in Evidence Theory is developed. This sensitivity analysis method generates marginal cumulative plausibility functions (CPFs) and cumulative belief functions (CBFs) and prioritizes the contribution of each factor by the Wasserstein distance (also known as the Kantorovich or Earth Movers distance) between the CBF and CPF. Using this method, a rank ordering of the simulation input factors can be produced with respect to uncertainty. Lastly, a procedure for prioritizing the impact of modeling choices on simulation output uncertainty in settings where multiple models are employed is developed. This analysis provides insight into the overall sensitivities of the system with respect to multiple modeling choices

    A Stochastic Model of Plausibility in Live-Virtual-Constructive Environments

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    Distributed live-virtual-constructive simulation promises a number of benefits for the test and evaluation community, including reduced costs, access to simulations of limited availability assets, the ability to conduct large-scale multi-service test events, and recapitalization of existing simulation investments. However, geographically distributed systems are subject to fundamental state consistency limitations that make assessing the data quality of live-virtual-constructive experiments difficult. This research presents a data quality model based on the notion of plausible interaction outcomes. This model explicitly accounts for the lack of absolute state consistency in distributed real-time systems and offers system designers a means of estimating data quality and fitness for purpose. Experiments with World of Warcraft player trace data validate the plausibility model and exceedance probability estimates. Additional experiments with synthetic data illustrate the model\u27s use in ensuring fitness for purpose of live-virtual-constructive simulations and estimating the quality of data obtained from live-virtual-constructive experiments

    Broadband and statistical characterization of echoes from random scatterers : application to acoustic scattering by marine organisms

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    Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2013The interpretation of echoes collected by active remote-sensing systems, such as sonar and radar, is often ambiguous due to the complexities in the scattering processes involving the scatterers, the environment, and the sensing system. This thesis addresses this challenge using a combination of laboratory and fi eld experiments, theoretical modeling, and numerical simulations in the context of acoustic scattering by marine organisms. The unifying themes of the thesis are 1) quantitative characterization of the spectral, temporal, and statistical features derived from echoes collected using both broadband and narrowband signals, and 2) the interpretation of echoes by establishing explicit links between echo features and the sources of scattering through physics principles. This physics-based approach is distinct from the subjective descriptions and empirical methods employed in most conventional fisheries acoustic studies. The fi rst part focuses on understanding the dominant backscattering mechanisms of live squid as a function of orientation. The study provides the first broadband backscattering laboratory data set from live squid at all angles of orientation, and conclusively con firms the fluidlike, weakly-scattering material properties of squid through a series of detailed comparisons between data and predictions given by models derived based on the distorted-wave Born approximation. In the second part, an exact analytical narrowband model and a numerical broadband model are developed based on physics principles to describe the probability density function of the amplitudes of echo envelopes (echo pdf) of arbitrary aggregations of scatterers. The narrowband echo pdf model signi cantly outperforms the conventional mixture models in analyzing simulated mixed assemblages. When applied to analyze fish echoes collected in the ocean, the numerical density of sh estimated using the broadband echo pdf model is comparable to the density estimated using echo integration methods. These results demonstrate the power of the physics-based approach and give a rst-order assessment of the performance of echo statistics methods in echo interpretation. The new data, models, and approaches provided here are important for advancing the eld of active acoustic observation of the ocean.Taiwan Merit Scholarship (NSC-095-SAF-I-564-021-TMS), Office of Naval Research (ONR; grants N00014-10-1-0127, N00014-08-1-1162, N00014-07-1-1034), National Science Foundation (NSF; grant OCE-0928801), Naval Oceanographic Offi ce (grant N62306007-D9002), WHOI Ocean Life Institute, and the WHOI Academic Programs O ffice funds

    2018 Faculty Excellence Showcase, AFIT Graduate School of Engineering & Management

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    Excerpt: As an academic institution, we strive to meet and exceed the expectations for graduate programs and laud our values and contributions to the academic community. At the same time, we must recognize, appreciate, and promote the unique non-academic values and accomplishments that our faculty team brings to the national defense, which is a priority of the Federal Government. In this respect, through our diverse and multi-faceted contributions, our faculty, as a whole, excel, not only along the metrics of civilian academic expectations, but also along the metrics of military requirements, and national priorities

    Air Force Institute of Technology Research Report 2017

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    This Research Report presents the FY18 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs)

    Virtual environmental applications for buried waste characterization technology evaluation report

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    NATO Code of Best Practice for C2 Assessment

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    This major revision to the Code of Best Practice (COBP) for C2 Assessment is the product of a NATO Research and Technology Organisation (RTO) sponsored Research Group (SAS-026). It represents over a decade of work by many of the best analysts from the NATO countries. A symposium (SAS-039) was hosted by the NATO Consultation Command Control Agency (NC3A) that provided the venue for a rigorous peer review of the code. This new version of the COBP for C2 assessment builds upon the initial version of the COBP produced by SAS-002. The earlier version focused on the analysis of ground forces at a tactical echelon in mid- to high-intensity conflicts. In developing this new version of the COBP, SAS-026 focused on a changed geopolitical context characterized by a shift from preoccupation with a war involving NATO and the Warsaw Pact to concern for a broad range of smaller military conflicts and Operations Other Than War (OOTW). This version also takes into account the impact of significantly improved information-related capabilities and their implications for reducing the fog and friction traditionally associated with conflict. Significantly reduced levels of fog and friction offer an opportunity for the military to develop new concepts of operations, new organizational forms, and new approaches to C2, as well as to the processes that support it. In addition, SAS-026 was cognizant that NATO operations are likely to include coalitions of the willing that might involve Partnership for Peace (PfP) nations, other partners outside of NATO, international organizations, and NGOs. Cost analyses continue to be excluded because they differ among NATO members, so no single approach would be appropriate. Advances in technology are expected to continue at an increasing rate and spur both sustaining and disruptive innovation in military organizations. It is to be expected that this COBP will need to be periodically revisited in light of these developments.https://digitalcommons.odu.edu/msve_books/1012/thumbnail.jp

    Air Force Institute of Technology Research Report 2016

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    This Research Report presents the FY16 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs)
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