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A Multi-Objective Approach to Optimal Deployment Policies for Wireless Sensor Networks Using Drop Points
Get PDFThis research addresses the development of deployment policies for aerially dropped sensors in a wireless sensor network (WSN). Multi-objective genetic algorithm (GA) and simulated annealing meta-heuristic techniques, along with Monte Carlo simulation are used to identify policies with the aim of maximizing coverage and minimizing the number of sensors deployed. The policies developed from these techniques are then compared against uniform sensor distribution, as well as initial deployment policies that focus sensors in the center and edge of the region, as well as evenly deployed over the region. A total of 29 non-dominated policies were identified from the GA and SA techniques. Larger networks favored a modified even distribution, while smaller networks favored a modified center-heavy distribution. These non-dominated solutions range in size from 137 to 729 sensors and from 0.2389 to 0.9393 coverage. These solutions mostly meet or surpass coverage for initial solutions of comparable network sizes
Automated Image Registration for Titanium Aircraft Components via Resolution-Robust Parallel Neural Networks
Get PDFTitanium alloys are vital to the structural integrity of military and commercial aircraft, comprising numerous critical components. These components are composed of microtexture regions (MTRs) that, at a specific size and orientation, can lead to aircraft failure. Existing MTR testing methods, such as Electron Backscatter Diffraction, often fall short in effectively detecting these MTRs without causing damage to the component. Addressing this gap, this thesis develops a Parallel Convolutional Neural Network (CNN) model tailored for multi-resolution image registration of Polarized Light Microscopy (PLM) images to enhance MTR identification in a non-invasive manner. The findings reveal a significant enhancement in the model’s ability to register images accurately at lower resolutions, with the F-statistic for the Mean Squared Error (MSE) regression indicating a strong predictive capability (p=0.0069), suggesting that the model’s performance significantly improves as the resolution diminishes. Furthermore, the model notably outperforms established methods such as Mutual Information and SIFT, with statistically significant differences in mean SAD values (p\u3c0.0001), underscoring its potential for non-destructive evaluation techniques. These advancements in non-destructive evaluation techniques significantly enhance the operational readiness and safety of military and commercial aircraft by offering a more accurate, reliable, and non-invasive method for MTR identification
Analyzing Cost Risk in Department of Defense Program Office Estimates
Get PDFThis research studies cost risk for Department of Defense (DoD) acquisition programs during development and has three overarching objectives: 1) analyze the degree of change in cost risk (quantified as risk dollars) as programs mature, 2) analyze the accuracy of cost risk estimates (quantified as risk error) as programs progress, and 3) adopt risk analysis techniques common in the commercial banking industry to analyze cost risk in DoD programs. For the first objective, some evidence of significant positive trends in relative risk dollars is found for ACAT 1, 2, and 3 programs. For the second objective, there is no strong evidence to suggest the accuracy of risk dollars has a trend for any ACAT level. For the third objective, distributions of risk error are created based on ACAT designation and analyzed close to the tails to assess inaccurate DoD cost risk estimates in the most extreme circumstances (termed tail risk exposure). The research finds that the tail risk exposure tends to decrease as ACAT 1 programs mature; however, the tail risk exposure tends to increase for ACAT 2 and 3 programs. Additionally, the tail risk exposure is highest for ACAT 1 programs until 25% work complete and highest for ACAT 3 programs after 50% work complete
A Computer and Processor Analysis: Developing Cost Relationships and Factors of Satellite Subsystems
Get PDFBy establishing the United States Space Force in 2019, the United States recognized the space domain as a primary focus and prioritized the rapid fielding, amplification, and development of their space enterprise. One step to dominate the domain is to efficiently manage costs within the USSF space satellite portfolio. To achieve this step, it is paramount to understand the importance of lower-level cost driving components, like microelectronics, within the work breakdown structure (WBS) of each space satellite program. In this thesis, one area of cost-driving microelectronic is investigated within the lower-level of the WBS: computers and processors. These components on board space satellites act as a core hardware mechanism to assist the USSF in meeting mission requirements to dominate the domain. Over time, the importance of computers and processors have only increased, and cost analysts need to understand potential generational changes associated to cost and their future estimates. To investigate these changes, this research develops one cost estimating relationship (CER) and creates several cost factors for computers and processors in the USSF space satellite portfolio. Component weight remains a key predictive variable for cost, but the results suggest that generational changes do not always affect computer and processor hardware costs
Ezra Kotcher: The Father of the Bell X-1 and X-2
No full textThe Bell X-2 rocket plane was a less-than-successful follow-on to the famous Bell X-1 that broke the sound barrier in 1947. The author recently discovered that both aircraft were the brainchildren of Ezra Kotcher, a civilian professor, military officer, and senior administrator with the United States Air Force. The author, during his residency as a Summer Faculty Fellow at the United States Air Force Institute of Technology, had the opportunity to examine Colonel Kotcher’s personal technical correspondence relating to these programs. By sharing these contemporaneous photographs, memoranda, reports, and notes, we gain new insight into how the Bell X-1 and Bell X-2 came to be. It is interesting to find out what differences led to the success of the X-1 and the failure of the X-2, as both aircraft embodied a deeply rooted desire to build something where “form follows function.
Optimizing Hub and Spoke Selections for Adaptive Basing in Agile Combat Employment
Get PDFAdvancing technologies and emerging competitors within the Indo-Pacific region have rendered the use of fixed installations for United States Air Force (USAF) operations less than optimal for generating airpower. The adoption of Agile Combat Employment (ACE) is imperative and emphasizes a hub-and-spoke model. However, the methodology for selection of contingency locations remains undecided. Current selection of optimal sites hinges on an optimization framework, employing either rank-based or mathematical approaches that consider various criteria to assess and quantify each location. These criteria are then addressed through objectives and constraints, forming the basis for an effective decision-making process. This paper introduces two hybrid models utilizing ArcGIS and General Algebraic Modeling System (GAMS) to pinpoint hub-and-spoke locations. The dataset employed for analysis was created by a previous Air Force Institute of Technology (AFIT) student, encompassing utility scores for over 500 public airports across the Indo-Pacific region. Results from both hybrid models successfully identified hubs and spokes within specific countries, including Bangladesh, Cambodia, India, Indonesia, Japan, Malaysia, Philippines, South Korea, Thailand, and Vietnam. Moreover, the models illustrate the versatility and efficacy of optimization as a tool for site selection. By allowing decision-makers to delineate specific objectives and criteria, the optimization methodology enhances the overall effectiveness of future policy and planning endeavors in the establishment of new operating locations
Estimating DIS Performance Using Mininet
No full textReal time distributed simulation is an exceptionally useful tool for training and wargaming used by the military and industry alike. This research aims to provide scenarios and structures to evaluate the effect of distributing simulations among different compute nodes. Specific scenarios involve the analysis of performance as a function of latency and the degree network protocols and reliability affect simulation performance. Various standards exist for administering geographically separated simulations. The focus of this thesis will be on the Distributed Interactive Simulation standard, a peer-to-peer open standard for simulation messages to adhere to, but lessons can be extended to other standards
Style Guide for AFIT Dissertations, Theses, and Graduate Research Papers
Get PDFA primary component of graduate education at the Air Force Institute of Technology (AFIT) is the scholarly presentation of research results. In most programs graduates must submit a dissertation, thesis, or graduate research paper as the final step in fulfilling degree requirements. These documents make a statement about the student and the quality of the student’s research, the student’s department, and AFIT’s academic standards. Therefore, the purpose of this guide is to help students present their research results in a form that is acceptable to AFIT.
The student’s research committee will guide the intellectual content of a student’s research manuscript and may further specify certain aspects of style. This guide is intended to establish basic formatting requirements to ensure uniformity in the format and appearance of all manuscripts. Complying with the requirements listed in this guide will help students produce a research report in which they and AFIT can take pride, and it will help avoid format correction delays of the final submitted manuscript.
The Style Guide for AFIT Dissertations, Theses, and Graduate Research Papers (more simply referred to as the AFIT Style Guide) contains formatting, documentation, document marking, submission requirements, and other relevant guidance for students in AFIT’s Graduate School of Engineering and Management
Natural Language Processing Analysis of Online Reviews for Small Business: Extracting Insight from Small Corpora
Get PDFReceiving and acting on customer input is essential to sustaining and growing any service organization, particularly a small family business whose livelihood depends on strong relationships with its customers. The competitive advantage offered by advanced analytical approaches for supporting decisions is not trivial, and enterprises across virtually all domains of society are investing heavily in this emerging discipline. Natural Language Processing (NLP) is a subset of computer science that employs computational approaches to analyze human language; it is effective at extracting insight from text data but frequently requires large corpora to train its models, in the scale of thousands or millions of documents. This restricts its accessibility to those large enterprises with the capability to capture, store, manage, and analyze such corpora. This research explores a pilot study that applies NLP approaches, specifically topic modeling and large language models (LLM), to assist a small, family-owned business in assessing its strengths and weaknesses based on customer reviews. The relevant corpora of online Facebook, Google Reviews, TripAdvisor, and Yelp reviews is far smaller than ideal, numbering only in the hundreds. Results demonstrate that coherent and actionable insights from big-data approaches are obtainable and that small organizations are not automatically excluded from the benefits of these advanced analytical approaches, with complementary employment of both topic modeling and LLM presenting the greatest potential for similarly-positioned organizations to exploit
Phase Error Scaling Law in Two-Wavelength Adaptive Optics
Get PDFWe derive a simple, physical, closed-form expression for the optical-path difference (OPD) of a two-wavelength adaptive-optics (AO) system. Starting from Hogge and Butts’ classic OPD variance integral expression, we apply Mellin transform techniques to obtain series and asymptotic solutions to the integral. For realistic two-wavelength AO systems, the former converges slowly and has limited utility. The latter, on the other hand, is a simple formula in terms of the separation between the AO sensing (i.e., the beacon) and compensation (or observation) wavelengths. We validate this formula by comparing it to the OPD variances obtained from the aforementioned series and direct numerical evaluation of Hogge and Butts’ integral. Our simple asymptotic expression is shown to be in excellent agreement with these exact solutions. The work presented in this letter will be useful in the design and characterization of two-wavelength AO systems