Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Air Force Institute of Technology

2017

Discipline
Keyword
Publication
Publication Type

Articles 1 - 30 of 93

Full-Text Articles in Engineering

Transferable Multiparty Computation, Michael R. Clark, Kenneth M. Hopkinson Nov 2017

Transferable Multiparty Computation, Michael R. Clark, Kenneth M. Hopkinson

AFIT Patents

A method and apparatus are provided for secure multiparty computation. A set of first parties is selected from a plurality of first parties for computation. Inputs for computation associated with each party in the set of first parties are divided into shares to be sent to other parties in the set of first parties. The computation on the shares is performed by the set of first parties using multiparty computation functions. In response to a trigger event, shares of the set of first parties are transferred to a set of second parties selected from a plurality of second parties. The …

Go to article

Load Planning Processes To Enhance Cargo Compartment Utilization, Nathan J. Carlson, Adam D. Reiman, Robert E. Overstreet, Matthew A. Douglas Nov 2017

Load Planning Processes To Enhance Cargo Compartment Utilization, Nathan J. Carlson, Adam D. Reiman, Robert E. Overstreet, Matthew A. Douglas

Faculty Publications

Purpose: The United States Air Force often provides effective airlift for cargo distribution, but is at times inefficient. This paper aims to address the under-utilization of military airlift cargo compartments that plagues the airlift system.
Design/methodology/approach: The authors examine seven techniques designed to increase cargo compartment utilization and increase airlift utilization rates. The techniques were applied through load planning software to 30 real-world movements consisting of 159 sorties. They then ran each post-technique movement through a modeled flight environment to obtain cycle movement data. The metrics gained from both the load planning software and the modeled environment were regressed to …

Go to article

Use Of A Novel Infrared Wavelength-Tunable Laser Mueller-Matrix Polarimetric Scatterometer To Measure Nanostructured Optical Materials, Jason C. Vap, Stephen E. Nauyoks, Michael R. Benson, Michael A. Marciniak Oct 2017

Use Of A Novel Infrared Wavelength-Tunable Laser Mueller-Matrix Polarimetric Scatterometer To Measure Nanostructured Optical Materials, Jason C. Vap, Stephen E. Nauyoks, Michael R. Benson, Michael A. Marciniak

Faculty Publications

Nanostructured optical materials, for example, metamaterials, have unique spectral, directional, and polarimetric properties. Samples designed and fabricated for infrared (IR) wavelengths have been characterized using broadband instruments to measure specular polarimetric transmittance or reflectance as in ellipsometry or integrated hemisphere transmittance or reflectance. We have developed a wavelength-tunable IR Mueller-matrix (Mm) polarimetric scatterometer which uses tunable external-cavity quantum-cascade lasers (EC-QCLs) to tune onto and off of the narrowband spectral resonances of nanostructured optical materials and performed full polarimeteric and directional evaluation to more fully characterize their behavior. Using a series of EC-QCLs, the instrument is tunable over 4.37-6.54 μm wavelengths …

Go to article

Characterization And Scaling Study Of Energy Pathways In Small Four-Stroke Internal Combustion Engines, Jason R. Blantin Sep 2017

Characterization And Scaling Study Of Energy Pathways In Small Four-Stroke Internal Combustion Engines, Jason R. Blantin

Theses and Dissertations

A study of the efficiency and energy losses of a selection of five small (40 - 200 cm3 displacement) single cylinder, four-stroke engines was accomplished. The study was performed as part of a larger effort to improve the range and endurance of small internal combustion engines (ICE) that power Group II Unmanned Aerial Vehicles (UAVs). Little is known about the performance, efficiency, and allocation of energy losses for four-stroke ICEs in this size range. The goal of the study was to characterize these parameters for use in future research efforts. Three research objectives were developed to guide the study …

Go to article

A Location-Aware Middleware Framework For Collaborative Visual Information Discovery And Retrieval, Andrew J.M. Compton Sep 2017

A Location-Aware Middleware Framework For Collaborative Visual Information Discovery And Retrieval, Andrew J.M. Compton

Theses and Dissertations

This work addresses the problem of scalable location-aware distributed indexing to enable the leveraging of collaborative effort for the construction and maintenance of world-scale visual maps and models which could support numerous activities including navigation, visual localization, persistent surveillance, structure from motion, and hazard or disaster detection. Current distributed approaches to mapping and modeling fail to incorporate global geospatial addressing and are limited in their functionality to customize search. Our solution is a peer-to-peer middleware framework based on XOR distance routing which employs a Hilbert Space curve addressing scheme in a novel distributed geographic index. This allows for a universal …

Go to article

Dynamics Of Chemical Degradation In Water Using Photocatalytic Reactions In An Ultraviolet Light Emitting Diode Reactor, John E. Stubbs Sep 2017

Dynamics Of Chemical Degradation In Water Using Photocatalytic Reactions In An Ultraviolet Light Emitting Diode Reactor, John E. Stubbs

Theses and Dissertations

This work examined ultraviolet (UV) light emitting diodes (LED) and hydrogen peroxide in an advanced oxidation process in support of a USAF installation net zero water initiative. A UV LED reactor was used for degradation of soluble organic chemicals. There were linear relationships between input drive current, optical output power, and first order degradation rate constants. When drive current was varied, first order degradation rates depended on chemical identities and the drive current. When molar peroxide ratios were varied, kinetic profiles revealed peroxide-limited or radical-scavenged phenomena. Molar absorptivity helped explain the complexity of chemical removal profiles. Degradation kinetics were used …

Go to article

Evaluating Process Improvement Courses Of Action Through Modeling And Simulation, Joseph R. Owens Sep 2017

Evaluating Process Improvement Courses Of Action Through Modeling And Simulation, Joseph R. Owens

Theses and Dissertations

Quantifying an expected improvement when considering moderate-complexity changes to a process is time consuming and has potential to overlook stochastic effects. By modeling a process as a Numerical Design Structure Matrix (NDSM), simulating the proposed changes, and evaluating performance, quantification can be rapidly accomplished to understand stochastic effects. This thesis explores a method to evaluate complex process changes within Six Sigma DMAIC process improvement to identify the most desirable outcome amongst several improvement options. A tool to perform the modeling and evaluation is developed. This process evaluation tool is verified for functionality, then is demonstrated against generic processes, a case …

Go to article

Engineered Surfaces To Control Secondary Electron Yield For Multipactor Suppression, James M. Sattler Sep 2017

Engineered Surfaces To Control Secondary Electron Yield For Multipactor Suppression, James M. Sattler

Theses and Dissertations

A significant problem for satellites, vacuum electron devices, and particle accelerators is multipactor: an avalanche of electrons caused by recurring secondary electron emission (SEE) in a time-varying electric field. The consequences of multipactor range from temporary to permanent device failure. This research studied how surface topography can be engineered to minimize SEE and suppress multipactor. Two new semi-empirical models (one based on a 2D pore, the other based on a 3D pore) were developed to predict the secondary electron yield (SEY) of a porous surface based on pore aspect ratio and porosity. The models were validated with experimental SEY measurements …

Go to article

Effect Of Fused Filament Fabrication Process Parameters On The Mechanical Properties Of Carbon Fiber Reinforced Polymers, Abdulrahman S. Alwabel Sep 2017

Effect Of Fused Filament Fabrication Process Parameters On The Mechanical Properties Of Carbon Fiber Reinforced Polymers, Abdulrahman S. Alwabel

Theses and Dissertations

Carbon fiber reinforced polymer manufactured using additive manufacturing process is relatively a new process. The ability to predict the mechanical properties of these parts with high confidence will spread the use of these high-strength materials in more applications. The purpose of this research was to determine the effect of the build time between successive layers, arrangement of fiber and nylon layers, fiber start location, and the use of support material on the mechanical properties CFRP produced by additive manufacturing process using the MarkForged (MarkOne) 3D printer. A design of experiment (DOE) we preformed to develop a mathematical model describing the …

Go to article

Characterization Of Jet Fuel Combustion Emissions During A C-130 Aeromedical Evacuation Engines Running Onload, Michelle L. Page Sep 2017

Characterization Of Jet Fuel Combustion Emissions During A C-130 Aeromedical Evacuation Engines Running Onload, Michelle L. Page

Theses and Dissertations

The purpose of this research was to characterize jet fuel combustion emissions (JFCE) in an occupational setting. Prior research demonstrated that aircraft emit hazardous species, especially at engine start-up and ground idle. Complaints of eye, nose, and throat irritation from occupational exposures near aircraft exist. In this study JFCE were tested during an aeromedical evacuation engines running patient onload (ERO) on a C-130 Hercules at the 179th Airlift Wing, Mansfield-Lahm Air National Guard. Ultrafine particles, VOC, formaldehyde, carbon monoxide (CO), sulfuric acid, and metals were sampled simultaneously in approximate crew and patient breathing zones. Testing methods were portable condensation …

Go to article

Synthesis Of Non-Uniformly Correlated Partially Coherent Sources Using A Deformable Mirror, Milo W. Hyde Iv, Santasri Bose-Pillai, Ryan A. Wood Sep 2017

Synthesis Of Non-Uniformly Correlated Partially Coherent Sources Using A Deformable Mirror, Milo W. Hyde Iv, Santasri Bose-Pillai, Ryan A. Wood

Faculty Publications

The near real-time synthesis of a non-uniformly correlated partially coherent source using a low-actuator-count deformable mirror is demonstrated. The statistical optics theory underpinning the synthesis method is reviewed. The experimental results of a non-uniformly correlated source are presented and compared to theoretical predictions. A discussion on how deformable mirror characteristics such as actuator count and pitch affect source generation is also included.

Go to article

Simplex Solutions For Optimal Control Flight Paths In Urban Environments, Michael D. Zollars, Richard G. Cobb, David J. Grymin Aug 2017

Simplex Solutions For Optimal Control Flight Paths In Urban Environments, Michael D. Zollars, Richard G. Cobb, David J. Grymin

Faculty Publications

This paper identifies feasible fight paths for Small Unmanned Aircraft Systems in a highly constrained environment. Optimal control software has long been used for vehicle path planning and has proven most successful when an adequate initial guess is presented flight to an optimal control solver. Leveraging fast geometric planning techniques, a large search space is discretized into a set of simplexes where a Dubins path solution is generated and contained in a polygonal search corridor free of path constraints. Direct optimal control methods are then used to determine the optimal flight path through the newly defined search corridor. Two scenarios …

Go to article

Forecasting Us Army Enlistment Contract Production In Complex Geographical Marketing Areas, Joshua L. Mcdonald, Edward D. White, Raymond R. Hill, Christian Pardo Aug 2017

Forecasting Us Army Enlistment Contract Production In Complex Geographical Marketing Areas, Joshua L. Mcdonald, Edward D. White, Raymond R. Hill, Christian Pardo

Faculty Publications

Purpose: The purpose of this paper is to demonstrate an improved method for forecasting the US Army recruiting. Design/methodology/approach: Time series methods, regression modeling, principle components and marketing research are included in this paper. Findings: This paper found the unique ability of multiple statistical methods applied to a forecasting context to consider the effects of inputs that are controlled to some degree by a decision maker. Research limitations/implications: This work will successfully inform the US Army recruiting leadership on how this improved methodology will improve their recruitment process.
Practical implications: Improved US Army analytical technique for forecasting recruiting goals.

Go to article

Satellite Propulsion Spectral Signature Detection And Analysis For Space Situational Awareness Using Small Telescopes, Pamela L. Wheeler Aug 2017

Satellite Propulsion Spectral Signature Detection And Analysis For Space Situational Awareness Using Small Telescopes, Pamela L. Wheeler

Theses and Dissertations

Safe satellite operations are of utmost importance. Maintaining precise orbital maintenance places stringent performance requirements on current propulsion systems, which are often electric propulsion systems. Electron temperature is a commonly used diagnostic to determine the performance of a Hall thruster, and recent work has correlated near infrared (NIR) spectral measurements of ionization lines of xenon and krypton to electron temperature measurements. In the research herein, appropriate line spectra ratios are identified for each propellant type when used with remote space-to-ground observations. NIR plume emissions were used to characterize a 600 Watt Hall thruster for a variety of observation angles and …

Go to article

Modeling Micro-Porous Surfaces For Secondary Electron Emission Control To Suppress Multipactor, James M. Sattler, Ronald Coutu Jr., Robert A. Lake, Tod V. Laurvick, Tyson C. Back, Steven. B. Fairchild Aug 2017

Modeling Micro-Porous Surfaces For Secondary Electron Emission Control To Suppress Multipactor, James M. Sattler, Ronald Coutu Jr., Robert A. Lake, Tod V. Laurvick, Tyson C. Back, Steven. B. Fairchild

Faculty Publications

This work seeks to understand how the topography of a surface can be engineered to control secondary electron emission (SEE) for multipactor suppression. Two unique, semi-empirical models for the secondary electron yield (SEY) of a micro-porous surface are derived and compared. The first model is based on a two-dimensional (2D) pore geometry. The second model is based on a three-dimensional (3D) pore geometry. The SEY of both models is shown to depend on two categories of surface parameters: chemistry and topography. An important parameter in these models is the probability of electron emissions to escape the surface pores. This probability …

Go to article

On-Chip, High-Sensitivity Temperature Sensors Based On Dye-Doped Solid-State Polymer Microring Lasers, Lei Wan, Hengky Chandrahalim, Cong Chen, Qiushu Chen, Ting Mei, Yuji Oki, Naoya Nishimura, Lingjie Jay Guo, Xudong Fan Aug 2017

On-Chip, High-Sensitivity Temperature Sensors Based On Dye-Doped Solid-State Polymer Microring Lasers, Lei Wan, Hengky Chandrahalim, Cong Chen, Qiushu Chen, Ting Mei, Yuji Oki, Naoya Nishimura, Lingjie Jay Guo, Xudong Fan

Faculty Publications

We developed a chip-scale temperature sensor with a high sensitivity of 228.6 pm/°C based on a rhodamine 6G (R6G)-doped SU-8 whispering-gallery mode microring laser. The optical mode was largely distributed in a polymer core layer with a 30 μm height that provided detection sensitivity, and the chemically robust fused-silica microring resonator host platform guaranteed its versatility for investigating different functional polymer materials with different refractive indices. As a proof of concept, a dye-doped hyperbranched polymer (TZ-001) microring laser-based temperature sensor was simultaneously developed on the same host wafer and characterized using a free-space optics measurement setup. Compared to TZ-001, the …

Go to article

Electron Paramagnetic Resonance Study Of Neutral Mg Acceptors In Β-Ga2O3 Crystals, Brant E. Kananen, Larry E. Halliburton, Elizabeth M. Scherrer, K. T. Stevens, G. K. Foundos, K. B. Chang, Nancy C. Giles Aug 2017

Electron Paramagnetic Resonance Study Of Neutral Mg Acceptors In Β-Ga2O3 Crystals, Brant E. Kananen, Larry E. Halliburton, Elizabeth M. Scherrer, K. T. Stevens, G. K. Foundos, K. B. Chang, Nancy C. Giles

Faculty Publications

Electron paramagnetic resonance (EPR) is used to directly observe and characterize neutral Mg acceptors (Mg0Ga) in a β-Ga2O3 crystal. These acceptors, best considered as small polarons, are produced when the Mg-doped crystal is irradiated at or near 77 K with x rays. During the irradiation, neutral acceptors are formed when holes are trapped at singly ionized Mg acceptors (Mg−Ga). Unintentionally present Fe3+ (3d5) and Cr3+ (3d3) transition-metal ions serve as the corresponding electron traps. The hole is localized in a nonbonding p orbital on a threefold-coordinated oxygen ion …

Go to article

Implementing Conditional Inequality Constraints For Optimal Collision Avoidance, Nathan E. Smith, Christopher D. Arendt, Richard G. Cobb, Jonah A. Reeger Jul 2017

Implementing Conditional Inequality Constraints For Optimal Collision Avoidance, Nathan E. Smith, Christopher D. Arendt, Richard G. Cobb, Jonah A. Reeger

Faculty Publications

Current Federal Aviation Administration regulations require that passing aircraft must either meet a specified horizontal or vertical separation distance. However, solving for optimal avoidance trajectories with conditional inequality path constraints is problematic for gradient-based numerical nonlinear programming solvers since conditional constraints typically possess non-differentiable points. Further, the literature is silent on robust treatment of approximation methods to implement conditional inequality path constraints for gradient-based numerical nonlinear programming solvers. This paper proposes two efficient methods to enforce conditional inequality path constraints in the optimal control problem formulation and compares and contrasts these approaches on representative airborne avoidance scenarios. The first approach …

Go to article

Real-Time Camera Tracking System Using Optical Flow Feature Points, Daniel D. Doyle, Alan L. Jennings, Jonathan T. Black Jul 2017

Real-Time Camera Tracking System Using Optical Flow Feature Points, Daniel D. Doyle, Alan L. Jennings, Jonathan T. Black

AFIT Patents

A new apparatus and method for tracking a moving object with a moving camera provides a real-time, narrow field-of-view, high resolution and on target image by combining commanded motion with an optical flow algorithm for deriving motion and classifying background. Commanded motion means that movement of the pan, tilt and zoom (PTZ) unit is “commanded” by a computer, instead of being observed by the camera, so that the pan, tilt and zoom parameters are known, as opposed to having to be determined, significantly reducing the computational requirements for tracking a moving object. The present invention provides a single camera pan …

Go to article

Improving Resource Management In The Afghan Air Force, Jonathan D. Ritschel, Tamiko L. Ritschel Jul 2017

Improving Resource Management In The Afghan Air Force, Jonathan D. Ritschel, Tamiko L. Ritschel

Faculty Publications

The nascent Afghan Air Force (AAF) is rapidly changing with new platforms programmed and existing platforms expanding. As US and coalition forces draw down, the transition of financial responsibility from American to Afghan processes is on the horizon.

Go to article

Optimal Control Methods For Missile Evasion, Ryan W. Carr Jul 2017

Optimal Control Methods For Missile Evasion, Ryan W. Carr

Theses and Dissertations

Optimal control theory is applied to the study of missile evasion, particularly in the case of a single pursuing missile versus a single evading aircraft. It is proposed to divide the evasion problem into two phases, where the primary considerations are energy and maneuverability, respectively. Traditional evasion tactics are well documented for use in the maneuverability phase. To represent the first phase dominated by energy management, the optimal control problem may be posed in two ways, as a fixed final time problem with the objective of maximizing the final distance between the evader and pursuer, and as a free final …

Go to article

Analysis Of An Experimental Space Debris Removal Mission, Krista L.L. Roth Jun 2017

Analysis Of An Experimental Space Debris Removal Mission, Krista L.L. Roth

Theses and Dissertations

Encountering space debris is an ever-increasing problem in space exploration and exploitation, especially in Low Earth Orbit. While many space-faring governing bodies have attempted to control the orbital lifetime post mission completion of satellites and rocker bodies, objects already in orbit pose a danger to future mission planning. Currently, governments and academic institutions are working to develop missions to remove space debris; however, the proposed missions are typically costly primary missions. This research proposes an alternative to use an upper stage rocket, to be called a chaser, already launching a primary mission near the desired debris as a host for …

Go to article

Pvdf-Trfe Electroactive Polymer Mechanical-To-Electrical Energy Harvesting Experimental Bimorph Structure, William G. Kaval, Robert A. Lake, Ronald A. Coutu Jr. May 2017

Pvdf-Trfe Electroactive Polymer Mechanical-To-Electrical Energy Harvesting Experimental Bimorph Structure, William G. Kaval, Robert A. Lake, Ronald A. Coutu Jr.

Faculty Publications

Research of electrostrictive polymers has generated new opportunities for harvesting energy from the surrounding environment and converting it into usable electrical energy. Electroactive polymer (EAP) research is one of the new opportunities for harvesting energy from the natural environment and converting it into usable electrical energy. Piezoelectric ceramic based energy harvesting devices tend to be unsuitable for low-frequency mechanical excitations such as human movement. Organic polymers are typically softer and more flexible therefore translated electrical energy output is considerably higher under the same mechanical force. In addition, cantilever geometry is one of the most used structures in piezoelectric energy harvesters, …

Go to article

Measuring The Reflection Matrix Of A Rough Surface, Kenneth W. Burgi, Michael A. Marciniak, Mark E. Oxley, Stephen E. Nauyoks May 2017

Measuring The Reflection Matrix Of A Rough Surface, Kenneth W. Burgi, Michael A. Marciniak, Mark E. Oxley, Stephen E. Nauyoks

Faculty Publications

Phase modulation methods for imaging around corners with reflectively scattered light required illumination of the occluded scene with a light source either in the scene or with direct line of sight to the scene. The RM (reflection matrix) allows control and refocusing of light after reflection, which could provide a means of illuminating an occluded scene without access or line of sight. Two optical arrangements, one focal-plane, the other an imaging system, were used to measure the RM of five different rough-surface reflectors. Intensity enhancement values of up to 24 were achieved. Surface roughness, correlation length, and slope were examined …

Go to article

Stereoscopic 3-D Presentation For Air Traffic Control Digital Radar Displays, Jason G. Russi, Brent T. Langhals, Michael E. Miller, Eric L. Heft May 2017

Stereoscopic 3-D Presentation For Air Traffic Control Digital Radar Displays, Jason G. Russi, Brent T. Langhals, Michael E. Miller, Eric L. Heft

AFIT Patents

An apparatus and method of presenting air traffic data to an air traffic controller are provided. Air traffic data including a two dimensional spatial location and altitude for a plurality of aircraft is received. A disparity value is determined based on the altitude for each aircraft of the plurality of aircraft. Left and right eye images are generated of the plurality of aircraft where at least one of the left and right eye images is based on the determined disparity value. The left and right eye images are simultaneously displayed to the air traffic controller on a display. The simultaneously …

Go to article

The Myth Of Strategic And Tactical Airlift, Jacob D. Maywald, Adam D. Reiman, Alan A. Johnson, Robert E. Overstreet Apr 2017

The Myth Of Strategic And Tactical Airlift, Jacob D. Maywald, Adam D. Reiman, Alan A. Johnson, Robert E. Overstreet

Faculty Publications

In the 21st century, our ability to quickly and decisively deliver combat forces and equipment is of the utmost importance in achieving our national security objectives. The swiftness and flexibility of the US Air Force’s mobility airlift fleet is the key to executing a rapid global mobility strategy. The operational effectiveness and efficiency of military air transportation relies on the expertise and intuition of Air Mobility Command’s (AMC) mobility planners. Working in coordination with the United States Transportation Command (USTRANSCOM) and geographic combatant commands (GCC), AMC is responsible for the tasking and tracking of almost 900 daily mobility sorties worldwide. …

Go to article

A Portfolio Decision Analysis Study For Improving Consequence Of Facility Failure Indices, Michael J. Blaess Mar 2017

A Portfolio Decision Analysis Study For Improving Consequence Of Facility Failure Indices, Michael J. Blaess

Theses and Dissertations

The United States Air Force partially integrated the Mission Dependency Index (MDI) into its portfolio project selection model by assigning an MDI value to a facility type or real property category code (CATCODE) in lieu of assigning a unique MDI value to each facility through a structured interview process. This took an initial step to improve the Air Forces asset management practices; however, it failed to accurately capture the consequence of facility failure in some cases. Although a process to adjudicate the MDI value of individual facilities was created, it is still unknown how much the surveyed MDI value deviates …

Go to article

Relating Film Cooling Performance Between Ambient And Near Engine Temperatures, Christopher J. Vorgert Mar 2017

Relating Film Cooling Performance Between Ambient And Near Engine Temperatures, Christopher J. Vorgert

Theses and Dissertations

This thesis explores multiple topics, including the relative importance of nondimensional parameters that relate film cooling performance within different temperature regimes and the effects of internal coolant flow and coolant temperature on overall film cooling effectiveness. A Hastelloy model representative of a turbine blade was utilized for IR tests. Near engine temperatures were produced via premixed propane and air combustion in a Well-Stirred Reactor (WSR) with air supplied as the film coolant gas. Near ambient conditions used heated air for freestream flow and carbon dioxide, argon, or air as film coolant gases. It was found that even with multiple matched …

Go to article

A Scenario-Based Parametric Analysis Of Stable Marriage Approaches To The Army Officer Assignment Problem, Matthew D. Ferguson Mar 2017

A Scenario-Based Parametric Analysis Of Stable Marriage Approaches To The Army Officer Assignment Problem, Matthew D. Ferguson

Theses and Dissertations

This paper compares linear programming and stable marriage approaches to the assignment problem under conditions of uncertainty. Robust solutions should exhibit reduced variability in the presence of one or more additional constraints. Several variations of each approach are compared with respect to solution quality, as measured by the overall social welfare among Officers and Assignments, and robustness as measured by the number of changes after a number of randomized perturbations. We examine the contrasts between these methods in the context of assigning Army Officers among a set of identified assignments. Additional constraints are modeled after realistic scenarios faced by Army …

Go to article

Reliability And Cost Impacts For Attritable Systems, Bryan R. Bentz Mar 2017

Reliability And Cost Impacts For Attritable Systems, Bryan R. Bentz

Theses and Dissertations

Attritable systems trade system attributes like reliability and reparability to achieve lower acquisition cost and decrease cost risk. Ultimately, it is hoped that by trading these attributes the amount of systems able to be acquired will be increased. However, the effect of trading these attributes on system-level reliability and cost risk is difficult to express complicated reparable systems like an air vehicle. Failure-time and cost data from a baseline limited-life air vehicle is analyzed for this reliability and reparability trade study. The appropriateness of various reliability and cost estimation techniques are examined for these data. This research employs the cumulative …

Go to article

Next Last