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Full-Text Articles in Engineering

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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Neuromorphic Vision Sensors For Space-Based Applications, Jessica L. Horn Mar 2021

Neuromorphic Vision Sensors For Space-Based Applications, Jessica L. Horn

Theses and Dissertations

This research examines the viability of event-based vision (neuromorphic) sensors for future use on satellites. Outputting single pixel events only when a change in intensity is detected, event-based vision sensors offer a potential low power, low latency, high temporal resolution, and high dynamic range solution as compared to traditional CCD or CMOS camera technology. The commercial off-the-shelf DVS240C sensor, is analyzed to determine if operability is affected by launch conditions and the low Earth space environment through vacuum, thermal vacuum, and vibration tests. No appreciable changes in sensor operation was observed throughout testing. Additionally, the sensor was able to detect …

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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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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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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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Improving Manufacturability And Reducing Cracking In Additively Manufactured Tungsten Alloys, Christopher P. Fassio Mar 2021

Improving Manufacturability And Reducing Cracking In Additively Manufactured Tungsten Alloys, Christopher P. Fassio

Theses and Dissertations

Additively Manufactured tungsten suffers from low () densities due to high concentrations of microcracks as the printed layers cool past tungsten's high ductile to brittle transition temperature. In this study, tungsten-rhenium and tungsten rhenium hafnium carbide compositions were evaluated on density and tensile strength. In addition to varying the compositions of each alloy, printing parameters and post-processing methods were also compared. Print parameters varied for all compositions on an MLab 200R C using included the laser scan strategy, hatch spacing, scan speed, laser power, and print bed material. Post processing techniques of the WRe compositions included hot isostatic pressing and …

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Impendance Probe Payload Development For Space-Based Joint Service Collaboration, Brian T. Kay Mar 2021

Impendance Probe Payload Development For Space-Based Joint Service Collaboration, Brian T. Kay

Theses and Dissertations

Collaborations utilizing small spacecraft in near earth orbit between the U. S. Coast Guard Academy (CGA), Naval Research Lab (NRL), the U. S. Naval Academy (USNA), and the Air Force Institute of Technology (AFIT) have initiated scientific and engineering space-based experiments. Sourced opportunities like the VaSpace ThinSat missions have provided a platform for payload, sensor, and experiment development that would have otherwise been resource prohibitive. We have constructed an impedance probe payload derived from the existing ‘Space PlasmA Diagnostic suitE’ (SPADE) mission operating from NASA’s International Space Station. Currently both space and laboratory plasmas are investigated with AC impedance measurements …

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Optimizing Critical Values And Combining Axes For Multi-Axial Neck Injury Criteria, Ethan J. Gaston Mar 2021

Optimizing Critical Values And Combining Axes For Multi-Axial Neck Injury Criteria, Ethan J. Gaston

Theses and Dissertations

The Air Force employs ejection seats in its high-performance aircraft. While these systems are intended to ensure aircrew safety, the ejection process subjects the aircrew to potentially injurious forces. System validation includes evaluation of forces against a standard which is linked to the probability of injury. The Muti-Axial Neck Injury Criteria (MANIC) was developed to account for forces in all six degrees of freedom. Unfortunately, the MANIC is applied to each of the three linear input directions separately and applies different criterion values for each direction. These three separate criteria create a lack of clarity regarding acceptable neck loading, leading …

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An Empirical Analysis Of Dod Construction Task Order Performance, Adam B. Teston, Tyler S. Stout Mar 2021

An Empirical Analysis Of Dod Construction Task Order Performance, Adam B. Teston, Tyler S. Stout

Theses and Dissertations

Cost and schedule overrun plague over 50 of all construction projects, engendering diminished available funding that leads to deferred maintenance and impaired award ability for needed projects. Though existing research attempts to identify overruns sources, the results are inconclusive and frequently differ. Accordingly, this research reviews DoD construction contract data from the past ten years to identify the contract attributes of 79,894 projects that correlate with superior performance for use in future project execution. This research starts with creating a database that houses the largest single source of construction contract information. The research then evaluates the data to determine if …

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Supporting Space Domain Awareness Through The Development And Analysis Of Space Object Detection Algorithms Employed By Ground-Based Telescopes, Connor A. Paw Mar 2021

Supporting Space Domain Awareness Through The Development And Analysis Of Space Object Detection Algorithms Employed By Ground-Based Telescopes, Connor A. Paw

Theses and Dissertations

Detection algorithms are instrumental in maintaining space domain awareness, specifically in the observation, monitoring, and categorization of unknown space objects. State of the art detection algorithms utilize a matched filter or a spatial correlator on long exposure image data to make pixel-wise detection decisions. This thesis investigates the advantages and practical potential of two different post-processing detection algorithms that can be employed by ground-based telescopes. The first algorithm explored is based on a long exposure Fourier domain processing technique, while the second is centered around frame selection from a series of short exposure images. The results of the experiments performed …

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Characterizing Security Monitor And Embedded System Performance Across Distinct Risc-V Ip-Cores, Justin C. Tullos Mar 2021

Characterizing Security Monitor And Embedded System Performance Across Distinct Risc-V Ip-Cores, Justin C. Tullos

Theses and Dissertations

Embedded systems have seen a rapid integration into all forms of industry as they continue to shrink in size and cost. The increased demand has highlighted a need for secure systems that are robust to attacks and demonstrate reliable performance, especially if the system operation is time-critical. E orts to characterize the performance of secure systems have been obstructed either by proprietary restrictions or ineffective analysis. Proprietary technology limits a comprehensive validation of a system's security and the implications it might have on performance. Performance analysis that is disclosed often lacks sufficient statistical rigor needed for a complex system. A …

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Commuting Compositions For Quantum Circuit Reduction, Brenna R. Cole Mar 2021

Commuting Compositions For Quantum Circuit Reduction, Brenna R. Cole

Theses and Dissertations

Quantum circuit simplification improves program execution on quantum hardware by reducing error from prolonged environmental interaction and noisy gate operations. One simplification technique is template matching, which repeatedly conducts local optimization by replacing small sequences of gates within a circuit by optimized versions. Underlying this method is the problem of identifying sequences matching templates. This is challenging because some, but not all, gates can commute within a circuit. This means there may not be a subcircuit that matches a template in the original circuit specification, but a match may exist in an equivalent rearrangement of gates. In such cases, certain …

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Development Of A Testbed For Foot Mounted Based Pedestrian Dead Reckoning (Pdr) Systems, Jordan E. Eldridge Mar 2021

Development Of A Testbed For Foot Mounted Based Pedestrian Dead Reckoning (Pdr) Systems, Jordan E. Eldridge

Theses and Dissertations

Over the last several years of research into the field of Pedestrian Dead Reckoning (PDR), there have been varying degrees of success in providing a viable individual navigation system. The PDR solutions developed utilize everything from a single Inertial Measurement Units (IMU) to several IMUs with additional sensors. One specific PDR solution identified that by utilizing a micro-mechanical Inertial Measurement Unit (IMU) on each foot (along with the application of Zero Velocity Updates (ZUPT) and foot-to-foot range measurements) a reliable method of PDR tracking could be accomplished. Their study concludes that further evaluation is required for this foot-mounted solution to …

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A Cyber Threat Taxonomy And A Viability Analysis For False Injections In The Tcas, John W. Hannah Mar 2021

A Cyber Threat Taxonomy And A Viability Analysis For False Injections In The Tcas, John W. Hannah

Theses and Dissertations

This thesis provided background information on the Traffic Collision Avoidance System (TCAS). Additionally, the thesis developed a threat taxonomy for TCAS, resulting in the determination that a false injection attack presents the most comprehensive risk. Moreover, the thesis presents the development of a program to determine what ranges, altitudes, and relative bearings are most vulnerable to a false injection attack. The program includes test for all requirements of a successful false injection. Furthermore, the thesis presents an analysis of results and creates threat maps as situational awareness tools. Lastly, the thesis discusses potential solutions to the false injection attack, covers …

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Spatially Separable Blind Deconvolution Of Long Exposure Astronomical Imagery, Justin S. Lee Mar 2021

Spatially Separable Blind Deconvolution Of Long Exposure Astronomical Imagery, Justin S. Lee

Theses and Dissertations

In this thesis, a spatially separable blind deconvolution algorithm is demonstrated that achieves a significantly faster processing time and superior sensitivity when processing long-exposure image data of unresolvable objects from a ground-based telescope. The proposed approach takes advantage of the structure of the long exposure point spread functions radial symmetric characteristics to approximate it as a product of one dimensional horizontal and vertical intensity distributions. Objects at geosynchronous or geostationary orbit also can be well approximated as being spatially separable as they are, in general non-resolvable. The algorithms performance is measured by computing the mean-squared error compared with the true …

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An Analysis Of X-Band Radiation For Space Based Wireless Power Transmission, Noah W. Friz Mar 2021

An Analysis Of X-Band Radiation For Space Based Wireless Power Transmission, Noah W. Friz

Theses and Dissertations

The USAF is interested in developing a solar powered satellite power beaming system using X-Band radiation. To determine the expected level of transmission efficiency of the system, an atmospheric characterization and radiative transfer modeling system called LEEDR was employed. A study was conducted to validate LEEDRs performance while working with microwave frequencies by replicating brightness temperatures measured by a 10.7 GHz radiometer above the Pacific Ocean in 1999. The results were inconclusive. Brightness temperature vs. rain rate curves developed within other studies for X-Band radiation curves could be replicated within LEEDR, and therefore the associated path transmission and extinction values. …

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Infiniband Network Monitoring: Challenges And Possibilities, Kyle D. Hintze Mar 2021

Infiniband Network Monitoring: Challenges And Possibilities, Kyle D. Hintze

Theses and Dissertations

Within the realm of High Performance Computing, the InfiniBand Architecture is among the leading interconnects used today. Capable of providing high bandwidth and low latency, InfiniBand is finding applications outside the High Performance Computing domain. One of these is critical infrastructure, encompassing almost all essential sectors as the work force becomes more connected. InfiniBand is not immune to security risks, as prior research has shown that common traffic analyzing tools cannot effectively monitor InfiniBand traffic transmitted between hosts, due to the kernel bypass nature of the IBA in conjunction with Remote Direct Memory Access operations. If Remote Direct Memory Access …

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Low-Cost Terrestrial Demonstration Of Autonomous Satellite Proximity Operations, Zackary R. Hewitt Mar 2021

Low-Cost Terrestrial Demonstration Of Autonomous Satellite Proximity Operations, Zackary R. Hewitt

Theses and Dissertations

The lack of satellite servicing capabilities significantly impacts the development and operation of current orbital assets. With autonomous solutions under consideration for servicing, the purpose of this research is to build and validate a low-cost hardware platform to expedite the development of autonomous satellite proximity operations. This research aims to bridge the gap between simulation and existing higher fidelity hardware testing with an affordable alternative. An omnidirectional variant of the commercially available TurtleBot3 mobile robot is presented as a 3-DOF testbed that demonstrates a satellite servicing inspection scenario. Reference trajectories for the scenario are generated via optimal control using the …

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Stereo Camera Calibrations With Optical Flow, Joshua D. Larson Mar 2021

Stereo Camera Calibrations With Optical Flow, Joshua D. Larson

Theses and Dissertations

Remotely Piloted Aircraft (RPA) are currently unable to refuel mid-air due to the large communication delays between their operators and the aircraft. AAR seeks to address this problem by reducing the communication delay to a fast line-of-sight signal between the tanker and the RPA. Current proposals for AAR utilize stereo cameras to estimate where the receiving aircraft is relative to the tanker, but require accurate calibrations for accurate location estimates of the receiver. This paper improves the accuracy of this calibration by improving three components of it: increasing the quantity of intrinsic calibration data with CNN preprocessing, improving the quality …

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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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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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Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer Mar 2021

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 …

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Application Of Game Theory Based Design To U.S. Space Systems, Benjamin C. Donohoo Mar 2021

Application Of Game Theory Based Design To U.S. Space Systems, Benjamin C. Donohoo

Theses and Dissertations

Modern defense systems are designed to static sets of requirements and specifications. This process has worked well in the past but fails to account for the strategic interdependence of design choices made prior to operating systems. However, as the world becomes increasingly competitive, and as the space domain becomes increasingly congested and contested, such interdependence of design can be described using Game Theory. Game Theory is the mathematical study of strategy, actions and payoffs between rational, self-interested actors. Limited extant research has applied Game Theory to system design but focused on a single system being designed cooperatively within a single …

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Model Based Systems Engineering Demonstrator For Air Worthiness With Performance Data Of Department Of Defense Rotorcraft, Bretton M. Bethel Mar 2021

Model Based Systems Engineering Demonstrator For Air Worthiness With Performance Data Of Department Of Defense Rotorcraft, Bretton M. Bethel

Theses and Dissertations

Airworthiness is a process of certifying that an aircraft can be safety operated within specified bounds. This process is essential to ensuring the safety of the aircraft, its personnel, and the surrounding assets. A Model-Based Systems Engineering (MBSE) approach can be utilized as a method to improve the airworthiness process. MBSE is the methodology of creating and utilizing domain models as a means of exchanging and presenting information for a wide variety of disciplines to understand and replacing previous document-based exchange. The objective of this research is to develop a reference architecture with a MBSE approach to perform the airworthiness …

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A Reference Architecture For Rapid Cubesat Development, Sean R. Kelly Mar 2021

A Reference Architecture For Rapid Cubesat Development, Sean R. Kelly

Theses and Dissertations

The CubeSat class of nanosatellites has lowered the barrier of entry to space and has rapidly gained popularity in recent years. To successfully design a CubeSat system in a rapid cycle conducive to academic timelines, a Reference Architecture geared towards University CubeSat development would be helpful. A Reference Architecture would speed up the development process by providing a template, capturing previous work and lessons learned from subject matter experts, providing a framework to focus on the CubeSats design rather than the fine details of modeling software. A Reference Architecture can also add functionality that student teams could use and improve …

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A Fuzzy Framework For The Air Force Mission Dependency Index, Devin M. Depalmer Mar 2021

A Fuzzy Framework For The Air Force Mission Dependency Index, Devin M. Depalmer

Theses and Dissertations

AFIMSC completed an MDI modernization to support better risk-based decision-making by utilizing tactical mission-owner knowledge to quantify the relationship between facilities and the missions they enable. The resulting facility-mission risk scores leave room for improvement for better use of their intended purposes due to (1) the vulnerability of cognitive biases affecting survey responses due to the use of a traditional risk matrix (2) the lack of resolution between scores from risk ties and (3) the failure to include information from the operational and strategic organizational hierarchy level. This research addresses these concerns through the novel implementation of a fuzzy logic …

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An Analysis Of Error Structure And Theoretical First Unit Cost In Learning Curve Theory Models, Alexander D. Pollack Mar 2021

An Analysis Of Error Structure And Theoretical First Unit Cost In Learning Curve Theory Models, Alexander D. Pollack

Theses and Dissertations

The dilemma with learning curves and actual costs is "fitting square pegs into round holes." Alternative regression techniques or further modifications to Y=aXb may address discrepancies in modeling observed data with learning curves. Adequate data permits further analysis of the constants, variables, and factors that make up a learning curve model. The analysis involves trying a nonlinear solver on the traditional learning curve models (i.e., Wright's cumulative average theory and Crawford's unit learning curve theory) and changing the theoretical first unit cost (T1) to the actual first unit cost (A1). Mergers and acquisitions in the aircraft industry may have …

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Optimizing Cost And Performance Of Infrastrucure Alternatives At Contingency Bases In A Hub-And-Spoke Network, Kyle J. Rodriguez Mar 2021

Optimizing Cost And Performance Of Infrastrucure Alternatives At Contingency Bases In A Hub-And-Spoke Network, Kyle J. Rodriguez

Theses and Dissertations

Military contingency bases require substantial resources and funding sustain and are often not connected to an infrastructure grid. Infrastructure assets produce the required outputs for sustainment, but are often expensive and inefficient, producing a significant logistical burden. With the increasing near-peer threats of opposing military forces, there is a need for more self-sufficient contingency bases with alternatives that reduce resources usage and the cost of sustainment. Accordingly, the goal of this research is to develop an optimization model capable of selecting infrastructure alternative combinations that minimize the overall resource usage and cost of sustainment at the contingency base level.

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Comparison Of Decision Analysis Methods For A Cubesat Propulsion System, Jared L. Pilcher Mar 2021

Comparison Of Decision Analysis Methods For A Cubesat Propulsion System, Jared L. Pilcher

Theses and Dissertations

Low Earth Orbit (LEO) is becoming an increasingly congested orbital regime. As a result, propulsion systems on CubeSats are becoming a more desirable feature to provide them with collision avoidance capabilities. To date, there have been very few CubeSat launches with a propulsion system on them. Due to the relatively high cost of a propulsion system compared to the budget of small educational organizations, a decision analysis model is needed so that these organizations can make the best decision between whether to purchase a Commercial-Off-The-Shelf (COTS) product or to develop one within the organization. This research applies three decision analysis …

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Training Subject Matter Experts To Make Better Estimates, Cameron R. Scott Mar 2021

Training Subject Matter Experts To Make Better Estimates, Cameron R. Scott

Theses and Dissertations

Subject Matter Expert (SME) Elicitation is commonly used as a cost-estimation method when no historical data exists. The elicitation process assumes Subject Matter Experts are the resident experts in their individual fields of study. In addition, the process assumes SMEs provide reasonably trustworthy cost estimates that follow the tenets of probability theory. This last assumption is the subject of this study. A Navy sponsored e-learning course was created to help train SMEs in understanding probability distributions (O'Hagan, 2019). We conducted a study hypothesizing that taking the e-learning course would improve study participant accuracy in estimating confidence intervals for probability distributions.

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