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Articles 451 - 480 of 2141

Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

An Examination Of Grid Stability As It Relates To The Increased Integration Of Inverter-Based Resources, Daniel Voss May 2021

An Examination Of Grid Stability As It Relates To The Increased Integration Of Inverter-Based Resources, Daniel Voss

Electrical Engineering Undergraduate Honors Theses

There is currently a growing interest in increasing the amount of renewable energy resources connected to the bulk electric system (BES) that stems from various environmental, political, and social concerns. However, the differences between conventional generation resources and inverter-based resources (IBR)—namely wind and solar—pose new issues that make this increased integration a larger problem. In other studies, the increased penetration of renewable energy resources has resulted in weak-grid systems that are more susceptible to collapse. This comes as a result from the inability for IBRs to effectively provide enough reactive power, an effect especially apparent during fault conditions, which the …

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Locating Drone Battery Supply Stations To Facilitate The Delivery Of Medical Supplies In Low And Middle-Income Countries, Madeline Suellentrop May 2021

Locating Drone Battery Supply Stations To Facilitate The Delivery Of Medical Supplies In Low And Middle-Income Countries, Madeline Suellentrop

Industrial Engineering Undergraduate Honors Theses

In the sub-Saharan region of Africa, the inability to perform emergency blood transfusions due to an inadequate blood supply has led to high fatality rates, especially among women and children. The prevalence of disease in this region limits the supply of local blood donations and, if blood is imported, then the region’s poor infrastructure inhibits fast distribution. There is a need for a technological update in the current process that overcomes the limitations of regional transportation, and drones present one promising solution for delivering small, lightweight items such as blood units. The current focus of this new delivery method is …

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Regression Analysis Of Pacing When Running A Marathon, Hawkin Starke May 2021

Regression Analysis Of Pacing When Running A Marathon, Hawkin Starke

Industrial Engineering Undergraduate Honors Theses

Regression analysis can be an effective way of examining performance in the marathon event. By splitting up the race into segments or in runner terminology “splits” the significance of each segment as it relates to the total finish time can be explored. Because the idea of splits is already ingrained into the minds of runners, it makes intuitive sense to use these as the metrics to define a race. Additionally, marathons generally make participant age and gender date publicly available which can then be used to find trends within specific demographics. This tailors trends to smaller groups of people, making …

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Optimizing Garbage Pick-Up In Wahoo, Ne, Andrew Pace May 2021

Optimizing Garbage Pick-Up In Wahoo, Ne, Andrew Pace

Theses/Capstones/Creative Projects

This project seeks to optimize the garbage pickup routes of Roadrunner Transportation in Wahoo, Nebraska using operations research and optimization tools. Currently, the company has no formal procedure for determining these routes. Roadrunner Transportation would like to expand their operation and to do so in the most efficient manner. To determine efficient routes, the Capacitated Vehicle Routing Problem (CVRP) is applied, and a solution to this problem is obtained by implementing a simulated annealing heuristic algorithm. Results show that a total distance of approximately 70 miles can be obtained by this implementation using a small subset of the data provided …

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Optimization With Interval Data: New Problems, Algorithms, And Applications., Mohsen Mohammadi Dehcheshmeh May 2021

Optimization With Interval Data: New Problems, Algorithms, And Applications., Mohsen Mohammadi Dehcheshmeh

Electronic Theses and Dissertations

The parameters of real-world optimization problems are often uncertain due to the failure of exact estimation of data entries. Throughout the years, several approaches have been developed to cope with uncertainty in the input parameters of optimization problems, such as robust optimization, stochastic optimization, fuzzy programming, parametric programming, and interval optimization. Each of these approaches tackles the uncertainty in the input data with different assumptions on the source of uncertainty and imposes different requirements on the returned solutions. In this dissertation, the approach we take is that of interval optimization, and more specifically, interval linear programming. The two main problems …

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Noise Control In Sorting Conveyors, Eyra Herrera May 2021

Noise Control In Sorting Conveyors, Eyra Herrera

Mechanical Engineering Undergraduate Honors Theses

E-commerce has increased the necessity of effective material handling equipment in warehouses and distribution centers. Sorter conveyors systems facilitate material handling by providing a reliable and automated system to classify and distribute products in a gentle and rapid manner. With the steady increase of speed in sorter conveyors to satisfy today’s industry demand, some systems have started to produce high noise levels that could potentially affect workers’ health. Since decreasing the speed of these conveyors is not a viable option to decrease noise in sorter equipment, industries have opted to find other ways to apply noise control to their equipment. …

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Heuristics For Capacity Allocation And Queue Assignment In Congested Service Systems With Stochastic Customer Demand And Immobile Servers, Adam Colley Apr 2021

Heuristics For Capacity Allocation And Queue Assignment In Congested Service Systems With Stochastic Customer Demand And Immobile Servers, Adam Colley

Operations Research and Engineering Management

We propose easy-to-implement heuristics for a problem referred to in the literature as the facility location problem with immobile servers, stochastic demand, and congestion, or the service system design problem. The problem is typically posed as one of allocating capacity to a set of M/M/1 queues to which customers with stochastic demand are assigned with the objective of minimizing a cost function composed of a fixed capacity-acquisition cost, a variable customer-assignment cost, and an expected-waiting-time cost. The expected-waiting-time cost results in a non-linear term in the objective function of the standard binary programming formulation of the problem. Thus, the solution …

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A Behavioral Model For Simultaneous Event Execution In Sequential Discrete Event System Simulations, Brian David S. Dilinila Apr 2021

A Behavioral Model For Simultaneous Event Execution In Sequential Discrete Event System Simulations, Brian David S. Dilinila

Computational Modeling & Simulation Engineering Theses & Dissertations

The sequential execution of simultaneous events in a discrete event system simulation can cause unexpected behavior in a system. Current studies have provided approaches such as applying a priority order for simultaneous events. However, this is still a problem because executing simultaneous events in sequential order can still lead to two issues of simultaneous event conflicts: the case where simultaneous events cause changes to state variables required by other simultaneous events and the case where two or more simultaneous events cause changes to the same state variables. The objective of this thesis is to develop a behavioral model as a …

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Cost Functions Of Crabs: Applications Of Hermit Crab Shell Exchange Behavior To Vacancy Chain Modelling, Hannah Miele Apr 2021

Cost Functions Of Crabs: Applications Of Hermit Crab Shell Exchange Behavior To Vacancy Chain Modelling, Hannah Miele

Senior Honors Theses

Vacancy chain systems function as a method of resource distribution in domains such as housing and labor markets. Hermit crabs also employ vacancy chains as a method of shell exchange. Application of vacancy chain modelling in engineering has been attempted, but numerous flaws exist in the developed vacancy chain scheduling algorithm. This work addresses the lack of an appropriate vacancy chain cost function by developing a generalizable cost function based on hermit crab shell exchange behavior. The cost function’s purpose is enabling development of realistic engineering experiments and models based on real-world vacancy chain systems.

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A Dynamic Programming Approach To Determine Optimum Modularity Level In Industrial Packaging, Marshal Louie, Kumar B Mar 2021

A Dynamic Programming Approach To Determine Optimum Modularity Level In Industrial Packaging, Marshal Louie, Kumar B

Journal of Applied Packaging Research

Modular packaging facilitate customization for accommodating variable product sizes in a product family. When determining package sizes for product variability, packaging engineers does not find difficulty to determine package dimension for less product variety whereas if the product variety is more, then determining the dimension of modular package involves complex decision-making and time-consuming process to find the optimal solution. This in turn directly impacts the overall lead time of the supply chain. Thus, in this paper a dynamic programming is developed to determine the quantity and dimension of modular packages for every demand of assorted products sizes. The program helps …

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Predicting F-16 Cause Code H Micap Hours Using Jmp Regression Analysis, Scott E. Carr Mar 2021

Predicting F-16 Cause Code H Micap Hours Using Jmp Regression Analysis, Scott E. Carr

Theses and Dissertations

Emergency demands for aircraft parts, MICAPs (Mission Impaired Capability Awaiting Parts) are one of the leading issues affecting mission capability supply rates for fighter aircraft. Cause code H MICAPS, those with a known demand level, but no supply available, are particularly troublesome and difficult to resolve. These MICAPS are due to failures by the supply chain to replenish stock levels within acceptable time limits. Numerous studies have identified a clear need for proactive measures to reduce MICAP hours. This would significantly improve aircraft availability. This study uses regression analysis implemented in JMP software to build models with a goal of …

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Air Combat Maneuvering Via Operations Research And Artificial Intelligence Methods, James B. Crumpacker Mar 2021

Air Combat Maneuvering Via Operations Research And Artificial Intelligence Methods, James B. Crumpacker

Theses and Dissertations

Within visual range air combat requires rapid, sequential decision-making to survive and defeat the adversary. Fighter pilots spend years perfecting maneuvers for these types of engagements, yet the emergence of unmanned, autonomous vehicle technologies elicits a natural question - can an autonomous unmanned combat aerial vehicle (AUCAV) be imbued with the necessary artificial intelligence to perform air combat maneuvering tasks independently? We formulate and solve the air combat maneuvering problem to examine this question, developing a Markov decision process model to control an AUCAV seeking to destroy a maneuvering adversarial vehicle. An approximate dynamic programming (ADP) approach implementing neural network …

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Exploring The Limits Of Strategic Thought: Evaluating How Different Communication Modalities Affect The Nature Of Strategic Decision-Making Using Cognitive Hierarchy, Stephen D. Donnel Mar 2021

Exploring The Limits Of Strategic Thought: Evaluating How Different Communication Modalities Affect The Nature Of Strategic Decision-Making Using Cognitive Hierarchy, Stephen D. Donnel

Theses and Dissertations

This research examines and quantifies the degree to which both information communication modality and the situational complexity affect individuals' ability to process the provided information and determine an effective strategy. Human subject testing herein consists of benign benevolent intervention involving the presentation of a series of strategic situations. For each situation, a participant attempts to identify their best response for a two-player, normal-form game with complete information. In each such game, players seek to maximize their own utility while considering their own actions, their opponent's actions, and each player's respective preferences over outcomes resulting from the possible combinations of actions. …

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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 Mar 2021

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 …

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Reducing Military Personnel Flight Wait Times Using A Simulation, Matthew D. Cornman Mar 2021

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 …

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Ccsfs/Ksc Total Lightning Warning Radii Optimization For Merlin Using Preexisting Lightning Areas, Kimberly G. Holland Mar 2021

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 …

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Improving Air Battle Management Target Assignment Processes Via Approximate Dynamic Programming, Joseph M. Liles Iv Mar 2021

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.

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The Impact Of Threat Levels At The Casualty Collection Point On Military Medical Evacuation System Performance, Nathaniel C. Dennie Mar 2021

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 …

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Defensive Counterair For Air Base Air Defense Using Directed Energy And Kinetic Energy Weapons, Andrew S. Wilson Mar 2021

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. …

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Stochastic Programming Design For West Africa Logistics Networks, Julius C. Walker Mar 2021

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 …

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Examining How Standby Assets Impact Optimal Dispatching Decisions Within A Military Medical Evacuation System Via A Markov Decision Process Model, Kylie Wooten Mar 2021

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 …

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Strategic Upgrade Scheduling And Portfolio Management To Fortify Contested Networks, Justin L. Anderson Mar 2021

Strategic Upgrade Scheduling And Portfolio Management To Fortify Contested Networks, Justin L. Anderson

Theses and Dissertations

The nuclear command, control, and communication (NC3) network provides an effective deterrent against adversaries by maintaining robust communication between assets, operators, and decision makers. NC3 must receive a series of upgrades to remain an effective deterrent against evolving threats around the globe. Given a contested network and a portfolio of network upgrades, this research seeks an optimal upgrade schedule to maximize network resilience in support of NC3 modernization. Our research contributes a model that solves a budget-constrained network upgrade scheduling problem (NUSP). The NUSP is a defender-attacker-defender tri-level optimization model that achieves fortification via selecting and scheduling network upgrades. The …

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The Impact Of Triage Classification Errors On Military Medical Evacuation System Performance, Emily S. Graves Mar 2021

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 …

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Automated Sentiment Analysis For Personnel Survey Data In The Us Air Force Context, Julia M. Haines Mar 2021

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 …

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The Autonomous Attack Aviation Problem, John C. Goodwill Mar 2021

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 …

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Bayesian Augmentation Of Cnn-Lstm For Video Classification With Uncertainty Measures, Emmie K. Swize Mar 2021

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 …

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Resupply Operations Of A Dispersed Infantry Brigade Combat Team Using Approximate Dynamic Programming, Camero K. Song Mar 2021

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.

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Meta-Heuristic Optimization Methods For Quaternion-Valued Neural Networks, Jeremiah P. Bill Mar 2021

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 …

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An Examination Of Potential Training Regression Recognition Algorithms For Pilot Training Next, Alex R. Gaines Mar 2021

An Examination Of Potential Training Regression Recognition Algorithms For Pilot Training Next, Alex R. Gaines

Theses and Dissertations

The initiative to reduce the Air Forces serious pilot shortage lead to the Pilot Training Next (PTN) program. Under PTN, student pilots progress at an individual rate while making increased use of simulator-based training resources. A previous thesis used data from the first PTN class to conceptualize and prototype a student training flight scheduler. This scheduler did not consider training events required to bring students back to achieved levels of performance if in fact that student performance had regressed. This thesis examines three classes of PTN student data to determine whether student regression in training progression can be detected. A …

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A Simulation Modeling The Effects Of Maintenance Personnel On Aircraft Sortie Generation, Benjamin D. Huffman Mar 2021

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 …

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