Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (110)
- Business (66)
- Aviation (48)
- Computer Sciences (40)
- Statistics and Probability (35)
-
- Social and Behavioral Sciences (33)
- Operations and Supply Chain Management (26)
- Human Resources Management (25)
- Applied Mathematics (18)
- Public Affairs, Public Policy and Public Administration (17)
- Management and Operations (13)
- Aerospace Engineering (12)
- Data Science (12)
- Applied Statistics (11)
- Defense and Security Studies (9)
- Design of Experiments and Sample Surveys (9)
- Artificial Intelligence and Robotics (7)
- Communication (6)
- Electrical and Computer Engineering (6)
- Government Contracts (5)
- Information Security (5)
- Law (5)
- Statistical Methodology (5)
- Training and Development (5)
- Aviation Safety and Security (4)
- Meteorology (4)
- Oceanography and Atmospheric Sciences and Meteorology (4)
- Keyword
-
- Decision support systems (14)
- Machine learning (13)
- Neural networks (Computer science) (13)
- Monte Carlo method (12)
- Scheduling (12)
-
- Linear programming (11)
- Simulation (11)
- Decision making (10)
- Forecasting (10)
- Mathematical optimization (10)
- Computer simulation (9)
- Integer programming (9)
- Neural networks (9)
- Operations research (9)
- Reinforcement learning (9)
- Computer war games (8)
- Goodness-of-fit tests (8)
- Military airlift (8)
- Optimization (8)
- Approximate dynamic programming (7)
- Combat--Computer simulation (7)
- Stochastic processes (7)
- Discrete-time systems (6)
- Discriminant analysis (6)
- Employee retention (6)
- Experimental design (6)
- Heuristic programming (6)
- Image processing (6)
- Response surfaces (Statistics) (6)
- Algorithms (5)
- Publication Year
- Publication Type
Articles 121 - 150 of 609
Full-Text Articles in Operational Research
The Impact Of Triage Classification Errors On Military Medical Evacuation System Performance, Emily S. Graves
The Impact Of Triage Classification Errors On Military Medical Evacuation System Performance, Emily S. Graves
Theses and Dissertations
In a deployed environment, evacuation requests of injured personnel are serviced by multiple forms of evacuation including medical evacuation (MEDEVAC) and casualty evacuation (CASEVAC). This thesis focuses on the optimal dispatching policy for MEDEVAC units when triage classification errors and blood transfusion kits are considered. A discounted, infinite-horizon Markov decision process (MDP) model is formulated to analyze the MEDEVAC dispatching problem and determine the optimal policy based on the status of the MEDEVAC units in the system, the priority level of incoming requests, and the locations from which requests originate. A notional, representational scenario based in Azerbaijan is utilized to …
Allocation Of Scarce Healthcare Resources In A Military Treatment Facility During A Pandemic: A Comparison Of Goal Programming And Portfolio Decision Analysis Methods, Donald B. Hale
Theses and Dissertations
In a pandemic, healthcare decisionmakers face the challenge of allocating critical, but scarce healthcare resources in a dynamic, uncertain environment. Their decisions will not only affect the patients coming to the hospital for treatment, but also the Military Treatment Facility's personnel responsible. The decisionmaker must decide how to allocate these resources to achieve multiple, conflicting objectives under multiple constraints. In response, we propose a methodology for the implementation of both Portfolio Decision Analysis and Goal Programming. The steps of this methodology provide a framework with which the decisionmaker can develop optimal allocation of resources. This framework was then applied to …
Improving Air Battle Management Target Assignment Processes Via Approximate Dynamic Programming, Joseph M. Liles Iv
Improving Air Battle Management Target Assignment Processes Via Approximate Dynamic Programming, Joseph M. Liles Iv
Theses and Dissertations
Military air battle managers face many challenges when directing operations in quickly evolving combat scenarios. These scenarios require rapid decisions to engage moving and unpredictable targets. In defensive operations, the success of a sequence of air battle management decisions is reflected by the friendly force's ability to maintain air superiority by defending friendly assets. We develop a Markov decision process (MDP) model of the air battle management (ABM)problem, wherein a set of unmanned combat aerial vehicles (UCAV) is tasked to defend a central asset from cruise missiles that arrive stochastically over time.
Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer
Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer
Theses and Dissertations
America's General Aviation sector has witnessed significant demographic shifts since the turn of the century. The number of certified, private pilots, non-fatal aircraft accidents, fatal aircraft accidents, and number of general aviation hours flown are all in decline. Meanwhile, the average age of an American private pilot has increased by several years. All of these factors indicate that the industry is in decline. This study determined via mathematical, linear regression that times relationship to the number of annual, fatal General Aviation accidents and the number of certified private pilots is negative. It also proved that the average age of the …
Resupply Operations Of A Dispersed Infantry Brigade Combat Team Using Approximate Dynamic Programming, Camero K. Song
Resupply Operations Of A Dispersed Infantry Brigade Combat Team Using Approximate Dynamic Programming, Camero K. Song
Theses and Dissertations
Military sustainment planners must consider the effective employment of Cargo Unmanned Aerial Vehicles (CUAVs) into resupply operations under austere threat conditions. Viewed as an inventory routing problem, the complexities of resupplying dislocated Forward Operating Bases (FOBs) under dangerous and dynamic conditions warrant additional features to the baseline problem. This research models a military stochastic inventory routing problem with multiple routing (MIL SIRP- MR) as a Markov decision process (MDP) model and provides high-quality policy solutions using a combination of approximate dynamic programming and ordinal optimization techniques.
Examining How Standby Assets Impact Optimal Dispatching Decisions Within A Military Medical Evacuation System Via A Markov Decision Process Model, Kylie Wooten
Theses and Dissertations
The Army medical evacuation (MEDEVAC) system ensures proper medical treatment is readily available to wounded soldiers on the battlefield. The objective of this research is to determine which MEDEVAC unit to task to an incoming 9-line MEDEVAC request and where to station a single standby unit to maximize patient survivability. A discounted, infinite-horizon continuous-time Markov decision process model is formulated to examine this problem. We design, develop, and test an approximate dynamic programming (ADP) technique that leverages a least squares policy evaluation value function approximation scheme within an approximate policy iteration algorithmic framework to solve practical-sized problem instances. A computational …
Stochastic Programming Design For West Africa Logistics Networks, Julius C. Walker
Stochastic Programming Design For West Africa Logistics Networks, Julius C. Walker
Theses and Dissertations
The USAFRICOM is studying methods to increase the resiliency of its West African Logistic Network, a hub-and-spoke network design responsible for sustaining long term humanitarian and security missions in the West Africa region. This paper employs a two-stage stochastic programming network design modeled on the WALN that builds a flexible supply chain capable of responding to periodic disruptions while maintaining peak resiliency. Elements such as cost, probability, and event-based disruption are integrated into the model to mirror challenges the WALN faces. We demonstrate that incorporating resilient based response mechanism provide a 90% reduction in cost compared to meeting the logistical …
A Simulation Modeling The Effects Of Maintenance Personnel On Aircraft Sortie Generation, Benjamin D. Huffman
A Simulation Modeling The Effects Of Maintenance Personnel On Aircraft Sortie Generation, Benjamin D. Huffman
Theses and Dissertations
Commanders and wargamers lack adequate tools to quickly determine the number of mission-capable (MC) aircraft and number of achievable sorties to support wargames and exercises. Even less understood is the impact of available maintenance personnel on sortie generation. The Expected-Number-of-In-Game-Mission-capable Aircraft (ENIGMA) simulation was recently developed to calculate the number of MC aircraft and number of sorties own accounting for the number and type of aircraft, scheduled sorties, mean-time-between-failure (MTBF), and mean-time-to-repair (MTTR). ENIGMA is extended by replacing the MTTR input with functions derived from actual numbers and types of maintenance personnel available. Functions in the form of response surface …
The Impact Of Threat Levels At The Casualty Collection Point On Military Medical Evacuation System Performance, Nathaniel C. Dennie
The Impact Of Threat Levels At The Casualty Collection Point On Military Medical Evacuation System Performance, Nathaniel C. Dennie
Theses and Dissertations
One of the primary duties of the Military Health System is to provide effective and efficient medical evacuation (MEDEVAC) to injured battlefield personnel. To accomplish this, military medical planners seek to develop high-quality dispatching policies that dictate how deployed MEDEVAC assets are utilized throughout combat operations. This thesis seeks to determine dispatching policies that improve the performance of the MEDEVAC system. A discounted, infinite-horizon continuous-time Markov decision process (MDP) model is developed to examine the MEDEVAC dispatching problem. The model incorporates problem features that are not considered under the current dispatching policy (e.g., myopic policy), which tasks the closest-available MEDEVAC …
Ccsfs/Ksc Total Lightning Warning Radii Optimization For Merlin Using Preexisting Lightning Areas, Kimberly G. Holland
Ccsfs/Ksc Total Lightning Warning Radii Optimization For Merlin Using Preexisting Lightning Areas, Kimberly G. Holland
Theses and Dissertations
The purpose of this research is to optimize lightning warning radii specifications for the 45th Space Wing (45 SW), thus reducing the number of unnecessary warnings that delay ground processing needed for space launch execution at Kennedy Space Center and Cape Canaveral Space Force Station. This thesis sought to answer two key research questions addressing: 1) What radius reduction effectively balances both safety and operations and do reduction recommendations from previous research align with results from the new detection system? 2) What insights can be gained from comparing measurement results for seasonal lightning events as well as lightning types? This …
Automated Sentiment Analysis For Personnel Survey Data In The Us Air Force Context, Julia M. Haines
Automated Sentiment Analysis For Personnel Survey Data In The Us Air Force Context, Julia M. Haines
Theses and Dissertations
When surveys are distributed across the Air Force (AF), whether it be an employee engagement survey, a climate survey, or similar, significant resources are put towards the development, distribution and analysis of the survey. However, when open ended questions are included on these surveys, respondent comments are generally underutilized, more often treated as a source for pull-quotes rather than a data source in and of themselves. This is due to a lack of transparency and confidence in the accuracy of machine-aided methods such as sentiment analysis and topic modeling. This confidence reduces further when the text has special context, such …
The Autonomous Attack Aviation Problem, John C. Goodwill
The Autonomous Attack Aviation Problem, John C. Goodwill
Theses and Dissertations
An autonomous unmanned combat aerial vehicle (AUCAV) performing an air-to-ground attack mission must make sequential targeting and routing decisions under uncertainty. We formulate a Markov decision process model of this autonomous attack aviation problem (A3P) and solve it using an approximate dynamic programming (ADP) approach. We develop an approximate policy iteration algorithm that implements a least squares temporal difference learning mechanism to solve the A3P. Basis functions are developed and tested for application within the ADP algorithm. The ADP policy is compared to a benchmark policy, the DROP policy, which is determined by repeatedly solving a deterministic orienteering problem as …
Bayesian Augmentation Of Cnn-Lstm For Video Classification With Uncertainty Measures, Emmie K. Swize
Bayesian Augmentation Of Cnn-Lstm For Video Classification With Uncertainty Measures, Emmie K. Swize
Theses and Dissertations
The success of Department of Defense (DoD) missions rely heavily on intelligence, surveillance, and reconnaissance (ISR) capabilities, which supply information about the activities and resources of an enemy or adversary. To secure this information, satellites and unmanned aircraft systems collect video data to be classified by either humans or machine learning networks. Traditional automated video classification methods lack measures of uncertainty, meaning the network is unable to identify those cases in which it predictions are made with significant uncertainty. This leads to misclassification, as the traditional network classifies each observation with same amount of certainty, no matter what the observation …
Defensive Counterair For Air Base Air Defense Using Directed Energy And Kinetic Energy Weapons, Andrew S. Wilson
Defensive Counterair For Air Base Air Defense Using Directed Energy And Kinetic Energy Weapons, Andrew S. Wilson
Theses and Dissertations
Air bases in key locations provide a strategic advantage to the countries that access them, and are at constant threat from adversaries. This research seeks to determine the optimal maneuvering of a fixed number of fighter aircraft in a combat air patrol for defensive counterair to maximally and effectively attrit the inbound cruise missile threat to a stationary high value asset such as an air base. The problem formulation identifies multiple objectives for the model: minimize the distance traveled for the fighters, minimize the time utilized to engage the incoming cruise missiles, and maximize the number of cruise missiles destroyed. …
Meta-Heuristic Optimization Methods For Quaternion-Valued Neural Networks, Jeremiah P. Bill
Meta-Heuristic Optimization Methods For Quaternion-Valued Neural Networks, Jeremiah P. Bill
Theses and Dissertations
In recent years, real-valued neural networks have demonstrated promising, and often striking, results across a broad range of domains. This has driven a surge of applications utilizing high-dimensional datasets. While many techniques exist to alleviate issues of high-dimensionality, they all induce a cost in terms of network size or computational runtime. This work examines the use of quaternions, a form of hypercomplex numbers, in neural networks. The constructed networks demonstrate the ability of quaternions to encode high-dimensional data in an efficient neural network structure, showing that hypercomplex neural networks reduce the number of total trainable parameters compared to their real-valued …
Reducing Military Personnel Flight Wait Times Using A Simulation, Matthew D. Cornman
Reducing Military Personnel Flight Wait Times Using A Simulation, Matthew D. Cornman
Theses and Dissertations
A shortage of resources and system failures have put a strain on Military Personnel Flights (MPFs) being able to service their customers in a timely manner. Prolonged customer wait times are becoming a common problem in most MPFs creating problems between the relationship of the customers and leadership. This research uses historical data of an MPF to develop a simulation model of daily operations in an MPF. Subject matter expertise of current MPF operations and resource levels were used to provide a baseline model of the MPF queuing system. The analysis examines the effects of number of Defense Enrollment Eligibility …
Comparing Greedy Constructive Heuristic Subtour Elimination Methods For The Traveling Salesman Problem, Petar Jackovich, Bruce A. Cox, Raymond R. Hill
Comparing Greedy Constructive Heuristic Subtour Elimination Methods For The Traveling Salesman Problem, Petar Jackovich, Bruce A. Cox, Raymond R. Hill
Faculty Publications
Purpose — This paper aims to define the class of fragment constructive heuristics used to compute feasible solutions for the traveling salesman problem (TSP) into edge-greedy and vertex-greedy subclasses. As these subclasses of heuristics can create subtours, two known methodologies for subtour elimination on symmetric instances are reviewed and are expanded to cover asymmetric problem instances. This paper introduces a third novel subtour elimination methodology, the greedy tracker (GT), and compares it to both known methodologies. Design/methodology/approach — Computational results for all three subtour elimination methodologies are generated across 17 symmetric instances ranging in size from 29 vertices to 5,934 …
The Effects Of Aircraft Use And Available Repar Spares On Aircraft Sortie Generaiton: A Long-Duration Logistical Wargaming Simulationtool, Nathaniel M. Choo
The Effects Of Aircraft Use And Available Repar Spares On Aircraft Sortie Generaiton: A Long-Duration Logistical Wargaming Simulationtool, Nathaniel M. Choo
Theses and Dissertations
A long-duration logistical wargame simulation tool that can provide quick insights into the daily aircraft availability and the daily number of missions accomplished for a variety of operational scenarios is developed. This simulation tool is designed to be a stepwise wargaming support tool for adjudication within long-duration logistical wargames and provides the user many capabilities including, but not limited to, the ability to have multiple bases and types of aircraft. Additionally, the user has the ability to control types of part failures, control parts availability, control maintenance capabilities, and control number of mission scheduled. Finally, the user can account for …
Aligning Performance Management Systems For Lasting Outcomes In Humanitarian Operations, Kalyn M. Howard
Aligning Performance Management Systems For Lasting Outcomes In Humanitarian Operations, Kalyn M. Howard
Theses and Dissertations
Logistics is dynamic, expansive, and critical to organizational success. While it is generally believed that effective logistics management is associated with positive performance outcomes, the links between organizational practice and performance are understudied. This dissertation leverages resource-based theory and organizational learning theory to examine organizational practice and performance in non-traditional logistics settings, with particular focus on military organizations and humanitarian operational settings. First, a meta-analytical study establishes generalizable associations between various operations management practices and performance outcomes. Then, this is applied to dynamic humanitarian logistics settings, exploring how practitioners perceive practice and performance, and how this is reported and documented …
Database Analysis To Improve U.S. Transportation Command Forecasting Processes, Maxwell C. Thompson
Database Analysis To Improve U.S. Transportation Command Forecasting Processes, Maxwell C. Thompson
Theses and Dissertations
The United States Transportation Command (USTRANSCOM) facilitates air, land, and sea transportation for the DOD. On a periodic basis, a myriad of different agencies within USTRANSCOM project future workload to facilitate resource planning, budgeting, and reimbursable rate identification. Within USTRANSCOM, there are a variety of databases and metrics utilized for workload forecasts; neither a standard nor a preferred technique is prescribed. Currently, USTRANSCOM faces challenges in producing accurate workload forecasts [1]. These challenges can lead to unreliable budget requests and, ultimately, hinder the effectiveness and efficiency of USTRANSCOM [1]. For the purpose of routine aircraft movements of cargo and personnel, …
A Metamodel Recommendation System Using Meta-Learning, Megan K. Woods
A Metamodel Recommendation System Using Meta-Learning, Megan K. Woods
Theses and Dissertations
The importance and value of statistical predictions increase as data grows in availability and quantity. Metamodels, or surrogate models, provide the ability to rapidly approximate and predict information. However, selection of the appropriate metamodel for a given dataset is often arduous, and the choice of the wrong metamodel could lead to considerably inaccurate results. This research proposes and tests the framework for a metamodel recommendation system. The implementation allows for virtually any dataset and preprocesses data, calculates meta-features, evaluates the performance of various metamodels, and learns how the data behaves via meta-learning, thus preparing and bettering itself for future recommendations. …
Explaining Weapon System Sustainment's Impact To Aircraft Availability, Michael D. Ingram
Explaining Weapon System Sustainment's Impact To Aircraft Availability, Michael D. Ingram
Theses and Dissertations
This research focused on understanding the phenomena behind the cost growth of Weapon System Sustainment (WSS) and the simultaneous degradation in USAF aircraft system availability. The primary modelling technique used was Ordinary Least Squares (OLS) while incorporating temporal effect. Other studies have looked at cost factors related to the Flying Hour Program, flying conditions and age. This study found empirical relationships between each of the four WSS business processes and the lead time in months it takes to realize improvements in system aircraft availability.
Predicting Upper Atmospheric Weather Conditions Utilizing Long-Short Term Memory Neural Networks For Aircraft Fuel Efficiency, Garrett A. Alarcon
Predicting Upper Atmospheric Weather Conditions Utilizing Long-Short Term Memory Neural Networks For Aircraft Fuel Efficiency, Garrett A. Alarcon
Theses and Dissertations
Aviation fuel is a major component of the Air Force (AF) budget, and vital for the core mission of the AF. This study investigated the viability of LSTMs to increase the accuracy of deterministic NWP models, while also investigating the ability to reduce model generation time. Increased forecast accuracy for wind speeds could be implemented into existing flight path models to further increase fuel efficiency, while reduced modeling times would allow flight planners to generate a flight plan in rapid response situations. The most viable model consisted of an ensemble of six LSTMs trained o six coordinates. The model's error …
Heuristic Approaches For Near-Optimal Placement Of Gps-Based Multi-Static Radar Receivers In American Coastal Waters, Brandon J. Hufstetler
Heuristic Approaches For Near-Optimal Placement Of Gps-Based Multi-Static Radar Receivers In American Coastal Waters, Brandon J. Hufstetler
Theses and Dissertations
Narcotics smuggling across the Caribbean Sea is a growing concern for the United States Coast Guard. One vector for this illicit trafficking is via small aircraft. This thesis proposes a multi-static radar architecture using the Global Positioning System (GPS) constellation as a transmission source to detect these aircraft as they transit a detection fence. The system developed in this thesis relies on the forward-scatter phenomenon in which a radar shadow is cast by a target as it crosses in front of a transmitter, creating a measurable difference in the signal amplitude at the receiver. This thesis first develops a mathematical …
Analysis And Forecasting Of The 360th Air Force Recruiting Group Goal Distribution, Tyler Spangler
Analysis And Forecasting Of The 360th Air Force Recruiting Group Goal Distribution, Tyler Spangler
Theses and Dissertations
This research utilizes monthly data from 2012-2017 to determine economic or demographic factors that significantly contribute to increased goaling and production potential in areas of the 360th Recruiting Groups. Using regression analysis, a model of recruiting goals and production is built to identify squadrons within the 360 RCGs zone that are capable of producing more or fewer recruits and the factors that contribute to this increased or decreased capability. This research identifies that a zones high school graduation rate, the number of recruiters, and the number of JROTC detachments in a zone are positively correlated with recruiting goals and that …
Analysis With Dynamic Bayesian Networks Compared To Simulation, Aaron J. Salazar
Analysis With Dynamic Bayesian Networks Compared To Simulation, Aaron J. Salazar
Theses and Dissertations
This research compares simulations to Dynamic Bayesian Networks in analyzing situations. The research applies models that have known output mean and variance. Queueing systems have theoretical values of the steady-state mean and variance for the number of entities in the system. Monte Carlo simulation development is broken down into two separate approaches: discrete-event simulation and time-oriented simulation. The discrete-event simulation uses pseudo-random numbers to schedule and trigger future events (i.e. customer arrivals and services) and is based on the generated objects.The time-oriented simulation utilizes fixed-width time intervals and updates the system state according to a stochastic process for the set …
Research In Defense Logistics: Where Are We And Where Are We Going?, George A. Zsidisin, Amanda Bresler, Benjamin T. Hazen, Keith F. Schneider, Taylor H. Wilkerson
Research In Defense Logistics: Where Are We And Where Are We Going?, George A. Zsidisin, Amanda Bresler, Benjamin T. Hazen, Keith F. Schneider, Taylor H. Wilkerson
Faculty Publications
The purpose of this paper is to provide insight on high-interest areas of research in defense-related logistics and supply chain management and opportunities for advancing theory and practice in this domain.
A Scenario-Based Parametric Analysis Of The Army Personnel-To-Assignment Matching Problem, Matthew D. Ferguson, Raymond R. Hill, Brian J. Lunday
A Scenario-Based Parametric Analysis Of The Army Personnel-To-Assignment Matching Problem, Matthew D. Ferguson, Raymond R. Hill, Brian J. Lunday
Faculty Publications
This study aims to compare linear programming and stable marriage approaches to the personnel assignment problem under conditions of uncertainty. Robust solutions should exhibit reduced variability of solutions in the presence of one or more additional constraints or problem perturbations added to some baseline problems.
Several variations of each approach are compared with respect to solution speed, solution quality as measured by officer-to-assignment preferences and solution robustness as measured by the number of assignment changes required after inducing a set of representative perturbations or constraints to an assignment instance. These side constraints represent the realistic assignment categorical priorities and limitations …
Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake
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 …
Air Force Space Programs: Comparing Estimates To Final Development Budgets, Christopher Elworth, Edward D. White, Jonathan D. Ritschel, Gregory E. Brown
Air Force Space Programs: Comparing Estimates To Final Development Budgets, Christopher Elworth, Edward D. White, Jonathan D. Ritschel, Gregory E. Brown
Faculty Publications
This article analyzes how development budget estimates, as reported in the Selected Acquisition Reports, change over time for primarily Air Force space programs. Government acquisition policy emphasizes the importance of developing an accurate point estimate for programs to ensure program budget efficiency; however, statistics imply space programs tend to underspend at the beginning of the program and to overspend at the end of Initial Operational Capability. This suggests new phasing methods that reflect the unique needs of space and perhaps other developmental-type programs by allocating more of the budget in later years rather than at the beginning of the program, …