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Full-Text Articles in Engineering

Tracked Vehicle Physics-Based Energy Modelling And Series Hybrid System Optimisation For The Bradley Fighting Vehicle, Travis E. Mcwhirter, Torrey J. Wagner, John E. Stubbs, Denise M. Rizzo, Jada B. Williams Dec 2019

Tracked Vehicle Physics-Based Energy Modelling And Series Hybrid System Optimisation For The Bradley Fighting Vehicle, Travis E. Mcwhirter, Torrey J. Wagner, John E. Stubbs, Denise M. Rizzo, Jada B. Williams

Faculty Publications

A hybrid electric tracked ground vehicle (HETGV) can reduce military fuel usage, however a review of current tools determined they are not suitable to estimate HEGTV performance. Based on topographic data and vehicle attributes, this research developed an estimation tool by creating a model to determine tracked vehicle energy and fuel requirements, and using these requirements, created a HEGTV cost and performance optimisation for the Bradley fighting vehicle energy system. The optimised design reduced fuel consumption by 15%, and met the vehicle's peak power requirement of 365 kW, with a recommended configuration of a 135 kW generator and 100 kWh …


An Agent Based Model Of Passenger Boarding For Examining Commercial Aircraft Boarding Strategies, Frank W. Ciarallo, Raymond R. Hill, Kerry K. Ward Dec 2019

An Agent Based Model Of Passenger Boarding For Examining Commercial Aircraft Boarding Strategies, Frank W. Ciarallo, Raymond R. Hill, Kerry K. Ward

Faculty Publications

We use an agent-based simulation methodology to study airline passenger boarding using measures that reflect both the customer experience and airline efficiency perspective. This approach supports exploration of models of actual aircraft used in practice and detailed modeling of passenger dynamics. This paper discusses the modeling approach and a set of experiments comparing several boarding strategies from practical settings as well as the literature.


Evaluating The Resiliency Of Industrial Internet Of Things Process Control Using Protocol Agnostic Attacks, Hector L. Roldan Dec 2019

Evaluating The Resiliency Of Industrial Internet Of Things Process Control Using Protocol Agnostic Attacks, Hector L. Roldan

Theses and Dissertations

Improving and defending our nation's critical infrastructure has been a challenge for quite some time. A malfunctioning or stoppage of any one of these systems could result in hazardous conditions on its supporting populace leading to widespread damage, injury, and even death. The protection of such systems has been mandated by the Office of the President of the United States of America in Presidential Policy Directive Order 21. Current research now focuses on securing and improving the management and efficiency of Industrial Control Systems (ICS). IIoT promises a solution in enhancement of efficiency in ICS. However, the presence of IIoT …


Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake Dec 2019

Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake

Theses and Dissertations

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 …


Development Of Cislunar Space Logistics Networks For Satellite Constellation Support Using Event-Driven Generalized Multi-Commodity Network Flows, Alexander R. Collins Nov 2019

Development Of Cislunar Space Logistics Networks For Satellite Constellation Support Using Event-Driven Generalized Multi-Commodity Network Flows, Alexander R. Collins

Theses and Dissertations

As space becomes an increasingly congested domain, the risk of damage to satellite constellations is increasing. In response, there is an increasing need for capabilities for unmanned repair, refueling, and reconstitution (R3) of those constellations. Cislunar orbits offer a promising storage and low-cost transfer solution for on-orbit service vehicles and replacement satellites to leverage those capabilities. This research makes use of mixed-integer linear programming-based logistics models to determine the situations in which a cislunar mission architecture would offer a cost-effective alternative to Earth-based R3. The network models presented in this research make use of the latest developments in Event-Driven Generalized …


Insulation Sensitivity Analysis For An Optimized Fabric Shelter Off-Grid Hybrid Energy System, Jay F. Pearson [*], Torrey J. Wagner, Steven Schuldt Oct 2019

Insulation Sensitivity Analysis For An Optimized Fabric Shelter Off-Grid Hybrid Energy System, Jay F. Pearson [*], Torrey J. Wagner, Steven Schuldt

Faculty Publications

During military and disaster relief operations, connecting to an established electrical grid is rarely an option. In these situations, camps consisting of poorly insulated fabric shelters are predominantly powered by inefficient diesel generators that require frequent fuel resupply. In order to reduce the fuel demand of these generators, camps may utilize photovoltaic-battery systems. This paper presents an innovative cost-performance model capable of optimizing solar array size, battery backup system, and shelter insulation type to minimize the operating cost of powering a single fabric shelter. Model performance was evaluated using one year of insolation, weather and energy requirement data from a …


Operational Decision Making Under Uncertainty: Inferential, Sequential, And Adversarial Approaches, Andrew J. Keith Aug 2019

Operational Decision Making Under Uncertainty: Inferential, Sequential, And Adversarial Approaches, Andrew J. Keith

Theses and Dissertations

Modern security threats are characterized by a stochastic, dynamic, partially observable, and ambiguous operational environment. This dissertation addresses such complex security threats using operations research techniques for decision making under uncertainty in operations planning, analysis, and assessment. First, this research develops a new method for robust queue inference with partially observable, stochastic arrival and departure times, motivated by cybersecurity and terrorism applications. In the dynamic setting, this work develops a new variant of Markov decision processes and an algorithm for robust information collection in dynamic, partially observable and ambiguous environments, with an application to a cybersecurity detection problem. In the …


Persuasion, Political Warfare, And Deterrence: Behavioral And Behaviorally Robust Models, William N. Caballero Jun 2019

Persuasion, Political Warfare, And Deterrence: Behavioral And Behaviorally Robust Models, William N. Caballero

Theses and Dissertations

This dissertation examines game theory models in the context of persuasion and competition wherein decision-makers are not completely rational by considering two complementary threads of research. The first thread of research pertains to offensive and preemptively defensive behavioral models. Research in this thread makes three notable contributions. First, an offensive modeling framework is created to identify how an entity optimally influences a populace to take a desired course of action. Second, a defensive modeling framework is defined wherein a regulating entity takes action to bound the behavior of multiple adversaries simultaneously attempting to persuade a group of decision-makers. Third, an …


Search And Rescue Operations Forecasting And Optimization, Zachary T. Hornberger Mar 2019

Search And Rescue Operations Forecasting And Optimization, Zachary T. Hornberger

Theses and Dissertations

United States Coast Guard District 14 is responsible for the execution of eleven statutory missions across the Pacific region. Despite having the largest geographic area of responsibility (AOR), District 14 has command of among the fewest resources to accomplish these missions. When search and rescue (SAR) emergencies occur, these events take immediate priority because the ability to rapidly coordinate available assets can be the difference between saving or losing a life. Using historic records of SAR incidents for District 14, we leverage an approach called the stochastic zonal distribution model to evaluate spatiotemporal trends in emergency rates and response strategies …


Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum Mar 2019

Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum

Theses and Dissertations

Continuing improvement in the field of AM of metals provides the opportunity for direct fabrication of aerospace parts. AM was once used in large part for rapid prototyping but improvements in technology and increases in the knowledge base of AM materials has provided the opportunity for manufacture of AM parts for operational use. The ability to create low numbers of unique parts without having to invest in expensive tooling provides great economic incentive to utilize this technique. IN718 is the most common high temperature alloy used in the aerospace industry and lends itself readily to formation by LPBF. The superior …


36% Reduction In Fuel Resupply Using A Hybrid Generator & Battery System For An Austere Location, David J. Chester [*], Torrey J. Wagner, Douglas S. Dudis Mar 2019

36% Reduction In Fuel Resupply Using A Hybrid Generator & Battery System For An Austere Location, David J. Chester [*], Torrey J. Wagner, Douglas S. Dudis

Faculty Publications

The DOD energy policy is to increase energy security resiliency, and mitigate costs in the use and management of energy[1] Forward operating bases (FOBs) are remote, austere base camps that support an operationally defined mission with a limited or no ability to draw from an energy grid and have historically relied on diesel-powered generators for the primary production of energy.[2] Generators are sized to meet a theoretical peak demand, but steady state loads are far below this peak, resulting in under-loaded generators.[3] Under-loaded diesel generators decrease efficiency and increase the need for maintenance, affecting the lifespan of …


The Nuclear Network: Multiplex Network Analysis For Interconnected Systems, Bethany L. Goldblum, Andrew W. Reddie, Thomas C. Hickey, James E. Bevins, Sarah Laderman, Nathaniel Mahowald, Austin P. Wright, Elie Katzenson, Yara Mubarak Jan 2019

The Nuclear Network: Multiplex Network Analysis For Interconnected Systems, Bethany L. Goldblum, Andrew W. Reddie, Thomas C. Hickey, James E. Bevins, Sarah Laderman, Nathaniel Mahowald, Austin P. Wright, Elie Katzenson, Yara Mubarak

Faculty Publications

States facing the decision to develop a nuclear weapons program do so within a broader context of their relationships with other countries. How these diplomatic, economic, and strategic relationships impact proliferation decisions, however, remains under-specified. Adding to the existing empirical literature that attempts to model state proliferation decisions, this article introduces the first quantitative heterogeneous network analysis of how networks of conflict, alliances, trade, and nuclear cooperation interact to spur or deter nuclear proliferation. Using a multiplex network model, we conceptualize states as nodes linked by different modes of interaction represented on individual network layers. Node strength is used to …


A Case For Open Mission Systems In Dod Aircraft Avionics, Michael J. Brown, R. David Fass, Jonathan D. Ritschel Jan 2019

A Case For Open Mission Systems In Dod Aircraft Avionics, Michael J. Brown, R. David Fass, Jonathan D. Ritschel

Faculty Publications

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.


A Sustainable Prototype For Renewable Energy: Optimized Prime-Power Generator Solar Array Replacement, Nathan Thomsen, Torrey J. Wagner, Andrew J. Hoisington, Steven J. Schuldt Jan 2019

A Sustainable Prototype For Renewable Energy: Optimized Prime-Power Generator Solar Array Replacement, Nathan Thomsen, Torrey J. Wagner, Andrew J. Hoisington, Steven J. Schuldt

Faculty Publications

Remote locations such as disaster relief camps, isolated arctic communities, and military forward operating bases are disconnected from traditional power grids forcing them to rely on diesel generators with a total installed capacity of 10,000 MW worldwide. The generators require a constant resupply of fuel, resulting in increased operating costs, negative environmental impacts, and challenging fuel logistics. To enhance remote site sustainability, planners can develop stand-alone photovoltaic-battery systems to replace existing prime power generators. This paper presents the development of a novel cost-performance model capable of optimizing solar array and Li-ion battery storage size by generating tradeoffs between minimizing initial …