Series:
NPS Outstanding Theses and Dissertations

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Degree-Earning Works
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Publication Search Results

Now showing 1 - 10 of 1430
  • Publication
    Development of a numerical tow tank with wave generation to supplement experimental efforts
    (Monterey, California: Naval Postgraduate School, 2017-12) Jones, Leo M.; Kwon, Young; Klamo, Joseph; Mechanical and Aerospace Engineering (MAE)
    This research investigates the capability of computational fluid dynamics to accurately model the performance of a vertically oscillating wave-generating wedge and resultant wave-induced loads on a submerged object in a tow tank. Specifically, the wave height, wave frequency, and unsteady forces on a submerged body were determined from numerous simulations and compared to experimentally measured data from nearly identical conditions as the simulations. Time histories of the water surface elevation were experimentally measured at various fixed locations in the tank to characterize the wave propagation. Once the wave environment was verified as being accurately captured, a fully submerged body was included in the experimental and simulated tanks. Identical waves were generated in both the physical and numerical environments, and passed over a square cross section submerged body that was located near-surface. The experimentally measured and numerically simulated unsteady forces and moments on the body were compared. The model captured loads experienced by the body quite accurately at low wavelengths, yet overestimated loads at higher wavelengths. Future studies should further refine simulation mesh resolution and investigate loads experienced by different geometries at a variety of depths to better understand over-prediction at large wavelengths.
  • Publication
    Automated network mapping and topology verification
    (Monterey, California: Naval Postgraduate School, 2016-06) Collier, Anthony R.; Singh, Gurminder; Gibson, John; Computer Science
    The current military reliance on computer networks for operational missions and administrative duties makes network stability and security a high priority for military units. The rapid rate at which technology changes means that constant and continued training is required for the skilled professionals who maintain and secure these computer networks. Current training methods are insufficient at representing the complex nature of the typical modern military computer network and the continually evolving nature of the attacks to networks. The Mapping, Awareness, and Virtualization Network Administrator Training Tool (MAVNATT) is a proposed system designed to replicate operational computer networks, through virtualization, providing a stable, accurate, and safely partitioned training environment that can closely mimic the configuration and functionality of any operational network. This research provides a solution for the mapping module of the MAVNATT system in the form of an application. During testing, we successfully developed network plans, visualized and verified those plans, scanned live networks for comparison and validation against those plans, and exported the network configurations for import by the MAVNATT awareness and virtualization modules. The mapping application was developed on a foundational framework that facilitates expansion and increased functionality during future research.
  • Publication
    Integrating Unmanned Aerial Vehicles into surveillance systems in complex maritime environments
    (Monterey, California: Naval Postgraduate School, 2013-09) Dimitriou, Georgios; Kennedy, Quinn; Computer Science; Lucas, Thomas W.
    One of the most important missions all Navies have is to constantly and sufficiently monitor their area of responsibility. This task becomes more challenging when a surveillance system operates in a complex environment with high traffic of merchant and fishing vessels and the existence of many islands. Potential tactics that targets might use increase the difficulty of this task. Integrating Unmanned Aerial Vehicles (UAVs) into a surveillance system that consists of ground radars and surface ships might enhance the systems capabilities and mitigate its vulnerabilities. In this study, the extremely complex maritime environment of the Aegean Sea is modeled in the Map Aware Non Uniform Automata (MANA) agent-based simulation environment to explore the effectiveness of UAVs in those conditions. The results from almost 100,000 simulated Intelligence, Surveillance, and Reconnaissance missions are analyzed using descriptive statistics, ANOVA, stepwise regression, and partition trees. It was found that by integrating one or two UAVs into a traditional surveillance system, it becomes more efficient in the detection and persistent surveillance of enemies and neutral targets. The most important factors that affect the surveillance systems performance are the detection capabilities of its sensors, the communication accuracy, and the enemys counter-detection capability. Thus, Greece and other countries with similar geographical characteristics should deploy UAVs in a maritime surveillance role.
  • Publication
    Strike package-target pairing real-time optimization for Airborne Battlespace Command and Control
    (Monterey, California. Naval Postgraduate School, 2010-09) McLemore, Connor S.; Carlyle, W. Matthew; Naval Postgraduate School (U.S.); Applied Science; Brown, Gerald
    When an air strike is requested against a target, the desired result is rapid arrival of a strike package of appropriately armed aircraft to destroy the target. However, the current manual system used by airborne battle managers is outdated, resulting in a slower strike package delivery time. This primitive system requires the operator to pair strike packages to targets manually in real time. A system that improves the efficiency of the airborne battle managers in a highworkload environment would result in faster strike package-target pairing and tasking, and might result in better parings. We develop a model, RASP, that creates strike package-target pairings that best satisfy operational requirements as outlined in various joint publications and clarified by Naval Strike and Air Warfare Center subject matter experts. RASP minimizes data entry while replicating the decision processes that military operators use to decide strike package-target pairings. The starting point for this thesis is the RAPT-OR model, developed by Zacherl in 2006, a weapon-target pairing tool we adapt for use in a real-time tactical decision aid for airborne battle managers.
  • Publication
    MECHANICAL PROPERTIES OF NANO BORON NITRIDE AND MICRO BORON CARBIDE REINFORCED ALUMINUM COLD SPRAY COATINGS
    (Monterey, CA; Naval Postgraduate School, 2022-12) Tauber, David M.; Ansell, Troy; Mechanical and Aerospace Engineering (MAE); Park, Chanman
    With regards to cold spraying, wear resistant metal coatings reinforced with boron nitride nanotubes (BNNTs) have remained unexplored when compared to carbon nanotube-based composites. Using commercially pure aluminum powder, 1-3 μm B4C powder, and BNNTs, multiple reinforced metal matrix composite powders were fabricated via high energy ball milling (HEBM). The powder compositions included an Al control, a 4 vol.% B4C composition, a 4 vol.% BNNT composition, and a 2 vol.% B4C with 2 vol.% BNNT composition. The compositions were sprayed onto AZ31 substrates using helium. The coatings were evaluated using nanoindentation, micro-indentation hardness, adhesion, and tensile tests. The coatings were then qualitatively evaluated under an optical microscope and scanning electron microscopes. Good dispersion of the ceramic reinforcements throughout the Al matrix was achieved via HEBM. A 14.1% increase and a 20.8% increase in micro-indentation hardness over the control were achieved for the Al/BNNT and the Al/B4C/BNNT compositions, respectively. Adhesion testing led to the Al/B4C/BNNT composition failing cohesively and the control failing adhesively at approximately the same force. The Al/B4C adhesion tests experienced a combination of the two failure modes at a 31.2% increase in force over the control. Stress vs. strain curves from tensile testing demonstrated that the load is partially supported by the cold spray coating until the coating ruptures.
  • Publication
    NOVEL CONTROL STRATEGIES FOR SHIPBOARD POWER CONVERSION SYSTEMS TO MEET THE PULSED LOAD REQUIREMENTS IN MIL-STD-1399
    (Monterey, CA; Naval Postgraduate School, 2022-12) Storm, Matthew P.; Oriti, Giovanna; Zhang, Di; Electrical and Computer Engineering (ECE)
    Large, immediate changes in electrical loading cause stresses in power systems. In large power systems, such as the grid used in residential, commercial and industrial applications, the typical change in electrical loading is a very small percentage of the power ratings of the electrical generators. As such, abrupt changes in electrical loading will cause relatively little stress to the power system. In naval applications, however, the distribution systems have a much lower power rating, so the stresses from load changes are much more significant. This thesis presents a novel solution to reduce the undesired effects of these load changes. Through the use of an energy storage system (ESS), switch-mode DC power converter, and an engineered control scheme, the undesired effects of large pulsed loads may be mitigated. A physics-based model of the system was constructed to provide a proof of concept of the solution, and is verified utilizing a laboratory prototype. The simulated and experimental measurements are compared against the specified constraints provided in MIL-STD-1399.
  • Publication
    ASSESSING THE EFFECTIVENESS OF PROFESSIONAL EMPLOYEE COMPENSATION EVALUATIONS IN DOD SERVICE CONTRACTS
    (Monterey, CA; Naval Postgraduate School, 2018-12) Flansburg, Stephen T.; Yoder, Elliott C.; Rendon, Rene G.; Department of Defense Management (DDM); Graduate School of Business and Public Policy (GSBPP)
    Today’s military relies on contractors, chiefly contracted services, at all levels—strategically, operationally, and tactically—to execute its mission more than it has at any other point in the history of the United States. Over the last decade, the DoD has consistently obligated the majority of its annual budget toward contracted services. One commonality across these service contracts is the inclusion of professional employees in the performance of many of these contracts. Over the same time period, the DoD has realized a protest loss rate of 50% at the U.S. Court of Federal Claims and of 43% at the Government Accountability Office related to the evaluation of compensation for professional employees. The purpose of this research is to conduct the first comprehensive analysis of the protest decisions to determine if a pattern of evaluations errors exists and to deepen the DoD’s understanding of the influencing factors that must be considered. The research identifies three distinct areas in which the DoD consistently erred in evaluations: (1) The evaluation was either inadequately documented or never conducted, (2) the data relied upon did not provide a meaningful basis to evaluate compensation, and (3) the analysis compared incorrect data from salary surveys. The research provides several actionable recommendations that may help decrease protest losses, including the use of the Streamlined Professional Employee Compensation Tool for Employee Realism (SPECTER).
  • Publication
    AUTONOMOUS AGENTS UTILIZING PASSIVE OPTICAL SENSING FOR CONTROL
    (Monterey, CA; Naval Postgraduate School, 2019-03) Stalford, Aaron M.; Dobrokhodov, Vladimir N.; Mechanical and Aerospace Engineering (MAE); Bingham, Brian S.
    The project addresses the problem of integrating a passive optical sensor onboard an autonomous unmanned aerial vehicle (UAV) and its operation in future missions against various targets/threats. The thesis develops the analytical and experimental software and hardware framework around a commercial-off-the-shelf quadcopter (COTSQ) for autonomous missions. The COTSQ features advanced autopilot capabilities along with an onboard optical sensor that is fully integrated into the control software. This research is applicable to any agent that has similar passive optical sensing capability. The work addresses the following key research questions and concepts: • Prove the sufficiency of the inner-outer loop design of a COTSQ autopilot to perform the autonomous sensing and detection of targets and threats in real time • What is the desired architecture of a high-level guidance controller to enable a single COTSQ and then multiple COTSQs to optimally search and automatically detect targets/threats? • How can the optical feed be used to facilitate detection and tracking of objects based on the real-time video feed from the UAVs? • How can this optical feed be utilized to advance the intelligent autonomy of the UAVs? • What are the fundamental limitations of achievable performance of the following components? o onboard instrumentation to enable robust execution of the search & detection mission and its robust scalability to potentially unlimited number of UAVs.
  • Publication
    A registrar administration system requirements analysis and product recommendation for Marine Corps University, Quantico, VA
    (Monterey, California. Naval Postgraduate School, 2011-09) Good, Daniel E.; Luqi; Pfeiffer, Karl; Naval Postgraduate School (U.S.); Computer Science (CS); Information Sciences (IS)
    Marine Corps University (MCU) is a relatively young organization and continues to mature as it brings more academic functionality and oversight under centralized control, especially in the area of Information Technology (IT). Much of MCU's IT control and responsibility still remains decentralized down to the school and college level. This research focuses on a specific IT capability, a Registrar Administration System (RAS). An RAS may also be termed a Student Information System (SIS). This type of system performs many functions. Some of them typically include the ability to hold or access personal student and faculty information; correlate students to courses completed, grades received and when; provide faculty a portal to upload course grades; and provide the Registrar's office access to generate transcripts. It may also include functionality for Registrar, course scheduling, or alumni needs. In this research, we conduct a requirements analysis (RA) to determine MCU's needs for this type of system. After understanding MCU's requirements, we conduct a market analysis to learn about systems that are being employed at institutions similar to MCU. Next, product characteristics, or factors, to be considered and Likert rating scales are defined in preparation for an evaluation of each system. We conduct a product comparison based on our system evaluations and conclude by recommending the best system for MCU.
  • Publication
    Developing simulated cyber attack scenarios against virtualized adversary networks
    (Monterey, California: Naval Postgraduate School, 2017-03) Aybar, Luis E.; Shaffer, Alan; Singh, Gurminder; Cyber Acadamic Group (CAG)
    Cyberspace is now recognized as a critical center of gravity for modern military forces. The ability to maintain operational networks, while degrading the enemy's network capability, is a key consideration for military commanders. Conducting effective cyber-attacks against sophisticated adversaries requires the ability to develop, test, and refine cyber-attack scenarios before they are used operationally, a requirement that is not as well defined in the cyber domain as it is in the physical domain. This research introduces several concepts to address this need, and creates a prototype for cyber-attack scenario development and testing in a virtual test environment. Commercial and custom software tools that provide the ability to conduct network vulnerability testing are reviewed for their suitability as candidates for the framework of this project. Leveraging the extensible architecture of the Malicious Activity Simulation Tool (MAST) custom framework allowed for the implementation of new interaction parameters, and provided temporal specificity and target discrimination of cyber-attack scenario tests. The prototype successfully integrated a virtualized test environment used to simulate an adversary network and the enhanced MAST capability to demonstrate the viability of a cyber-attack scenario development platform to address the needs of modern offensive cyber operations. Based on these results, we recommend continued development of MAST with the intent to ultimately deploy to Department of Defense cyber operations teams.