A Case for Open Mission Systems in DOD Aircraft Avionics

The DOD is adopting open mission systems (OMS) as the future in the military aviation environment. OMS proponents promise reduced costs and truncated schedules through increased competition in the marketplace and reduced coding efforts. To the best of our knowledge, no studies have examined the success of these open architectures in the DOD. Therefore, we investigate costs and schedule for a recent DOD avionics OMS demonstration platform in comparison to 13 historically analogous programs

Quantifying configuration-sampling error in Langevin simulations of complex molecular systems

While Langevin integrators are popular in the study of equilibrium properties of complex systems, it is challenging to estimate the timestep-induced discretization error: the degree to which the sampled phase-space or configuration-space probability density departs from the desired target density due to the use of a finite integration timestep. Sivak et al., introduced a convenient approach to approximating a natural measure of error between the sampled density and the target equilibrium density, the Kullback-Leibler (KL) divergence, in phase space, but did not specifically address the issue of configuration-space properties, which are much more commonly of interest in molecular simulations. Here, we introduce a variant of this near-equilibrium estimator capable of measuring the error in the configuration-space marginal density, validating it against a complex but exact nested Monte Carlo estimator to show that it reproduces the KL divergence with high fidelity. To illustrate its utility, we employ this new near-equilibrium estimator to assess a claim that a recently proposed Langevin integrator introduces extremely small configuration-space density errors up to the stability limit at no extra computational expense. Finally, we show how this approach to quantifying sampling bias can be applied to a wide variety of stochastic integrators by following a straightforward procedure to compute the appropriate shadow work, and describe how it can be extended to quantify the error in arbitrary marginal or conditional distributions of interest

Quantifying the Effects of Aircraft Engine Upgrades on Operating and Support Costs

For fixed wing aircraft within the U.S. Air Force, Operating and Support (O&S) costs encompass a large portion of total life cycle costs. O&S costs include fuel, maintenance, and engine upgrades. To the authors’ knowledge, no study to date has attempted to empirically quantify the realized effects of new aircraft engines on sustainment costs. Utilizing the Air Force Total Ownership Cost database, they focused on new engines appearing on the C-5s, C-130s, and C-135s. Although narrow in scope, results suggest newer engines have lower fuel costs. Maintenance costs for newer engines were not consistently higher or lower than the engines they replaced, although Contractor Logistics Support was not tracked by engine in this study. We found that savings from improved fuel efficiency tended to be greater than a potential increase in maintenance costs

Text Mining Analysis of Acquisition Reforms and Expert Views

Legislation, in the form of acquisition reforms, is historically enacted to address perceived cost, schedule, and performance problems in the defense acquisition system. Text mining is utilized to examine five major reforms and a compendium of views from 32 acquisition experts to identify commonalities and disconnects

Identifying rhesus macaque gene orthologs using heterospecific human CNV probes

AbstractWe used the Affymetrix® Genome-Wide Human SNP Array 6.0 to identify heterospecific markers and compare copy number and structural genomic variation between humans and rhesus macaques. Over 200,000 human copy number variation (CNV) probes were mapped to a Chinese and an Indian rhesus macaque sample. Observed genomic rearrangements and synteny were in agreement with the results of a previously published genomic comparison between humans and rhesus macaques. Comparisons between each of the two rhesus macaques and humans yielded 206 regions with copy numbers that differed by at least two fold in the Indian rhesus macaque and human, 32 in the Chinese rhesus macaque and human, and 147 in both rhesus macaques. The detailed genomic map and preliminary CNV data are useful for better understanding genetic variation in rhesus macaques, identifying derived changes in human CNVs that may have evolved by selection, and determining the suitability of rhesus macaques as human models for particular biomedical studies

Effects of carboxy-terminal modifications of proteinase 3 (PR3) on the recognition by PR3-ANCA

Effects of carboxy-terminal modifications of proteinase 3 (PR3) on the recognition by PR3-ANCA.BackgroundAutoantibodies directed against neutrophil proteinase 3 (PR3-ANCA) from patients with Wegener's granulomatosis and microscopic polyangiitis recognize conformational epitopes of PR3. During maturation of neutrophils, PR3 undergoes amino-terminal and carboxy-terminal processing. In contrast to amino-terminal processing, the effects of carboxy-terminal processing on recognition of PR3 by PR3-ANCA remain unknown. Carboxy-terminally modified or tagged recombinant PR3 (rPR3) molecules may be useful for the refinement of diagnostic assays and for the study of biological processes.MethodsThis study was designed to determine whether 293 cells can be used to express specifically designed carboxy-terminal variants of rPR3, and to evaluate the effects of different carboxy-terminal modifications on the recognition by PR3-ANCA in the capture ELISA.ResultsThe rPR3-variants secreted into the media supernatants of transfected 293 cells escaped proteolytic processing. Furthermore, in contrast to the effects of amino-terminal pro-peptide deletion on PR3-ANCA binding, carboxy-terminal modifications (deletion and additions) did not significantly affect recognition by PR3-ANCA.ConclusionsThis expression system is ideally suited for the expression of custom-designed carboxy-terminal rPR3 variants, and major conformational effects of carboxy-terminal modifications seem unlikely

Improving Software Cost Estimating Techniques in Defense Programs

Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumAs software becomes more ubiquitous in defense programs, there is a need to improve the accuracy and reliability of methods for estimating software size and cost. Historically, practitioners have used defined distributions in their estimating software to simulate likely outcomes. This research identifies new distributions of likely software costs and effective sizes through an analysis of Cost and Software Data Reports (CSDRs) as well as demonstrating the most appropriate distribution given certain program characteristics known at the genesis of the project. By utilizing various descriptive statistics and statistical tests, this research shows there are distributions that are more closely tailored to the actual qualities of a software program. In some instances, a broad and general distribution is sufficient; however, there are specific commodities, contractors, and system types that are distinctly different and require additional analysis. Overall, this research intends to equip practitioners with an arsenal of distributions and statistical information that will lead them to apply the best model to predict software size and cost, all with the goal of improving overall accuracy.Approved for public release; distribution is unlimited

Improving Software Cost Estimating Techniques in Defense Programs

Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumAs software becomes more ubiquitous in defense programs, there is a need to improve the accuracy and reliability of methods for estimating software size and cost. Historically, practitioners have used defined distributions in their estimating software to simulate likely outcomes. This research identifies new distributions of likely software costs and effective sizes through an analysis of Cost and Software Data Reports (CSDRs) as well as demonstrating the most appropriate distribution given certain program characteristics known at the genesis of the project. By utilizing various descriptive statistics and statistical tests, this research shows there are distributions that are more closely tailored to the actual qualities of a software program. In some instances, a broad and general distribution is sufficient; however, there are specific commodities, contractors, and system types that are distinctly different and require additional analysis. Overall, this research intends to equip practitioners with an arsenal of distributions and statistical information that will lead them to apply the best model to predict software size and cost, all with the goal of improving overall accuracy.Approved for public release; distribution is unlimited

Improving Software Cost Estimating Techniques in Defense Programs

Symposium PresentationApproved for public release; distribution is unlimited