Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Aerospace Engineering (1664)
- Electrical and Computer Engineering (1332)
- Operations Research, Systems Engineering and Industrial Engineering (1238)
- Physical Sciences and Mathematics (1164)
- Operational Research (605)
-
- Signal Processing (455)
- Computer Sciences (443)
- Civil and Environmental Engineering (421)
- Computer Engineering (414)
- Aviation (353)
- Electrical and Electronics (350)
- Physics (350)
- Materials Science and Engineering (329)
- Business (297)
- Navigation, Guidance, Control and Dynamics (250)
- Other Operations Research, Systems Engineering and Industrial Engineering (232)
- Systems Engineering (228)
- Electromagnetics and Photonics (190)
- Aerodynamics and Fluid Mechanics (188)
- Environmental Engineering (185)
- Engineering Science and Materials (176)
- Nuclear Engineering (176)
- Mechanical Engineering (169)
- Digital Communications and Networking (166)
- Space Vehicles (159)
- Optics (147)
- Management and Operations (144)
- Operations and Supply Chain Management (135)
- Semiconductor and Optical Materials (126)
- Keyword
-
- #antcenter (324)
- #csra (125)
- Global Positioning System (63)
- Image processing (61)
- #afcec (60)
-
- Optimization (54)
- Additive manufacturing (51)
- Decision making (51)
- Kalman filtering (51)
- Flight control (48)
- Machine learning (48)
- Target acquisition (47)
- Drone aircraft (46)
- Algorithms (45)
- Microelectromechanical systems (44)
- Composite materials (41)
- Artificial satellites (38)
- Synthetic aperture radar (38)
- Computer vision (37)
- Neural networks (Computer science) (37)
- Computer networks--Security measures (35)
- Signal processing (35)
- Finite element method (33)
- Scheduling (32)
- Simulation (31)
- Decision support systems (30)
- Neural networks (30)
- Remote sensing (28)
- Wireless communication systems (28)
- Silicon carbide (26)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 721 - 750 of 5699
Full-Text Articles in Engineering
Satellite Tt&C For Cubesats With Applications For Grissom-1, Michael J. Bittle
Satellite Tt&C For Cubesats With Applications For Grissom-1, Michael J. Bittle
Theses and Dissertations
This thesis describes the assessment and analysis performed to characterize the communication subsystem used for command and telemetry transmission in support of the Grissom-1 Mission (GM1). The GM1 is unique in that it represents the pathfinder for a standardized 6U bus that serves as the basis for future CubeSat missions to host a variety of technical and scientific payloads, as prioritized by the Department of Defense, requiring flight demonstration or access to the orbital environment. Lab-based testing within an anechoic chamber provided link margin data required to characterize the command and telemetry links of the GM1. Experimental data describing the …
Design And Testing Of A Composite Compressor Rotor, Mauro Noel V. De Leon
Design And Testing Of A Composite Compressor Rotor, Mauro Noel V. De Leon
Theses and Dissertations
Additive manufacturing (AM) and molding are manufacturing methods known for building representations or replicas of conceptualized engine components, but was considered impractical for manufacturing operating engine components. More recent technology has rendered composite materials (combining high-temperature polymers and fiber reinforcement) capable of withstanding the temperature and structural requirements to compete with conventional turbomachinery metals. This study explores the application of several high-temperature polymers (ULTEM 9085, Onyx-Carbon fiber, and Epoxy-Carbon fiber) and their survivability in the operating conditions of a P400 Engine compressor. The tests conducted for this study determined their viability as compressor materials. This study required conducting tensile specimen …
Leveraging Xgeo Orbits For Cislunar Space Domain Awareness, Jay Laone
Leveraging Xgeo Orbits For Cislunar Space Domain Awareness, Jay Laone
Theses and Dissertations
With recent interest in using cislunar orbits for a variety of missions, it is more important than ever to also have cislunar space domain awareness. This thesis aims to bridge the gap between traditional LEO/GEO architectures and the new cislunar orbit architectures with orbits higher than GEO but still within the Earth sphere of influence, called xGEO. This research effort first explores the feasibility of xGEO orbits by examining the errors that the two-body assumption builds over time. Findings suggest that the two body assumption can be used to varying degrees depending on the orbit radius. This study has found …
Investigation Of Additively Manufactured Molybdenum-Tungsten-Rhenium Alloys, Randolph T. Abaya
Investigation Of Additively Manufactured Molybdenum-Tungsten-Rhenium Alloys, Randolph T. Abaya
Theses and Dissertations
The process of creating metal components through additive manufacturing is changing the way different industries can avoid the shortcomings of traditional metal production. Metals such as tungsten, molybdenum, and rhenium have many advantages for different applications, especially when alloyed together. In this study, an additively manufactured alloy containing 70% molybdenum, 25% tungsten, and 5% rhenium (70Mo-25W-5Re) is tested for its strength, ductility, hardness, and porosity. The 70Mo-25W-5Re alloy is printed through Laser Powder Bed Fusion (LPBF) under different conditions such as printing speed and printing atmosphere. Additionally, the effects of post printing heat treatment are conducted to understand the advantages …
Effects Of A Nitrogen And Hydrogen Build Atmosphere On The Properties Of Additively Manufactured Tungsten, Dana C. Madsen
Effects Of A Nitrogen And Hydrogen Build Atmosphere On The Properties Of Additively Manufactured Tungsten, Dana C. Madsen
Theses and Dissertations
Additively manufactured tungsten was printed in pure nitrogen, nitrogen-2.5% hydrogen, and nitrogen-5% hydrogen atmospheres as part of a 2^3 full factorial designed experiment and subjected to room temperature and high-temperature three-point-bend testing, chemical analysis, hardness testing, and microstructural imaging techniques. The pure nitrogen specimens exhibited the highest strength and ductility at both high temperature and room temperature. Chemical analysis showed a 2-8x reduction in compositional oxygen relative to unprocessed powder. Hardness values for all samples was between 306.8 and 361.5 HV1. It is proposed that adding hydrogen into the build atmosphere reduced the available energy density for tungsten melting by …
Thermal Relaxation Of Shot Peen Induced Residual Stresses In A Nickel-Base Superalloy, Bryce E. Van Velson
Thermal Relaxation Of Shot Peen Induced Residual Stresses In A Nickel-Base Superalloy, Bryce E. Van Velson
Theses and Dissertations
Shot peening induces compressive residual stresses in components that positively influence fatigue life. Thermal and mechanical loading causes those residual stresses to relax. The hole drilling method and xray diffraction is used to measure the thermal relaxation of residual stresses in the nickel-base superalloy ME3.
Implementation And Characterization Of Ahr On A Xilinx Fpga, Andrew J. Dittrich
Implementation And Characterization Of Ahr On A Xilinx Fpga, Andrew J. Dittrich
Theses and Dissertations
A new version of the Adaptive-Hybrid Redundancy (AHR) architecture was developed to be implemented and tested in hardware using Commercial-Off-The-Shelf (COTS) Field-Programmable Gate Arrays (FPGAs). The AHR architecture was developed to mitigate the effects that the Single Event Upset (SEU) and Single Event Transient (SET) radiation effects have on processors and was tested on a Microprocessor without Interlocked Pipeline Stages (MIPS) architecture. The AHR MIPS architecture was implemented in hardware using two Xilinx FPGAs. A Universal Asynchronous Receiver Transmitter (UART) based serial communication network was added to the AHR MIPS design to enable inter-board communication between the two FPGAs. The …
Optimization Of A Multi-Layered Target For A Pulsed Power Neutron Source, Zachary D. Bretz
Optimization Of A Multi-Layered Target For A Pulsed Power Neutron Source, Zachary D. Bretz
Theses and Dissertations
The ability to create neutron environments is critical fora wide variety of applications including national security, materials science, and medical research. It is also helpful in medical, material, and other research. The U.S. Naval Research Laboratory (NRL), Washington, DC, is interested in leveraging their pulsed-power facilities to produce an in-house, relatively inexpensive neutron source. NRL’s facilities produce 2 MeV (from Gamble II) and 5 MeV (from Mercury) protons and deuterons. This research explored combinations of target materials to produce the most neutrons in the forward direction. Models of the reactions involved were first validated against literature experiments, then target designs …
Performance Assessment Of Navigation Using Carrier Doppler Measurements From Multiple Leo Constellations, Michael J. Hartnett
Performance Assessment Of Navigation Using Carrier Doppler Measurements From Multiple Leo Constellations, Michael J. Hartnett
Theses and Dissertations
The goal of this work is to characterize a novel navigation method which uses carrier Doppler shift measurements from LEO satellites. An ever-growing reliance on the GNSS has coincided with an increase in ways it can be degraded or denied, whether naturally occurring or man-made. These potentially disastrous threats to traditional navigation and timing have necessitated new technologies to augment GNSS in the case of an outage. LEO constellations, whose size and higher signal power make them potentially useful for navigation, are one technology that has been explored. The navigation algorithms detailed in this research use Doppler measurements from 8 …
Double Cone Flow Field Reconstruction Between Mach 4 And 12 Using Machine Learning Techniques, Trevor A. Toros
Double Cone Flow Field Reconstruction Between Mach 4 And 12 Using Machine Learning Techniques, Trevor A. Toros
Theses and Dissertations
No abstract provided.
Capability Development For Advanced (N,X) Nuclear Data Measurements, Brian G. Frandsen
Capability Development For Advanced (N,X) Nuclear Data Measurements, Brian G. Frandsen
Theses and Dissertations
Nuclear reaction data are the heart of radiation transport calculations, models, and simulations. Unique approaches are required to improve the measurement capability for many reactions where data are inaccurate or do not exist. First, the newly developed Gamma Energy Neutron Energy Spectrometer for Inelastic Scattering (GENESIS) provides the ability to measure neutron inelastic scattering cross sections on different targets. An initial experiment measuring the 16O(n,n’��) reaction calculated the count rate from the second excited state using the full energy and escape peaks. Second, a set of photocurable scintillator resin formulations capable of neutron-gamma discrimination were developed to support light-based …
Neutron Spectral Effect On Microelectronic Performance Response, Wade Kloppenburg
Neutron Spectral Effect On Microelectronic Performance Response, Wade Kloppenburg
Theses and Dissertations
Response of 2N2222 bipolar junction transistors to neutrons from a pulsed thermonuclear or pulsed fission source are researched. Measurements used for comparing performance included the base-collector junction current-voltage and capacitance-voltage characteristics and device gain degradation. Little change was detected in steady-state operation of the base-collector junction, but evidence in the dynamic and capacitance measurements establish effects based on environment. Experimental results are compared to literature results and parameters are explored using a device model simulation code.
Formulation And Characterization Of Fast-Curing Plastic Scintillators With High-Z Loading, Theodore W. Stephens
Formulation And Characterization Of Fast-Curing Plastic Scintillators With High-Z Loading, Theodore W. Stephens
Theses and Dissertations
Development of novel fast-curing plastic scintillators is highly advantageous due to their potential to be manufactured via 3D printing. Several formulations were developed that exhibit enhanced photon sensitivity, producing modest but discernible photopeaks at an incident gamma energy of 122 keV. The photon sensitivity is achieved via bismuth high-Z loading; however, this practice typically results in diminished light yields. Subsequent formulations, which varied the photoinitiator concentration and curing time, demonstrated successful curing with sufficient plastic hardness, reduced purple discoloration, reduced heat buildup during curing, and resulted in less cracking during the curing process, all of which were correlated with lower …
Examining Failures Of Kc-135s Using Survival Analysis, Vanessa I. R. Unseth
Examining Failures Of Kc-135s Using Survival Analysis, Vanessa I. R. Unseth
Theses and Dissertations
The United States Air Force manages an inventory of 396 KC-135 Stratotanker aircraft. With mission capability rates falling and total non-mission capability supply rates increasing, it is necessary to take a deeper look at recurrent failures. The study applies non-parametric and semi-parametric survival models to a dataset retrieved from LIMS-EV to look at the duration(s) until failure for the KC-135. Results of non-parametric models show cumulative failure rates increase as sorties or flight hours increase. In addition, semi-parametric models or Cox proportional hazards models with frailty confirm that locations or air bases are not associated with recurrent failures.
A Study On The Early Stages Of Degradation Of Multi-Component Alloy Surfaces In Extreme Environments Using The Multi-Cell Monte Carlo Method, Tyler D. Dolezal
A Study On The Early Stages Of Degradation Of Multi-Component Alloy Surfaces In Extreme Environments Using The Multi-Cell Monte Carlo Method, Tyler D. Dolezal
Theses and Dissertations
A computational toolset is presented and used in two examples that examined the interactions between structural materials and their extreme environments. A multi-cell Monte Carlo algorithm was developed to generate thermodynamically realistic solid-state alloy systems. These structures served as the foundation upon which surface slab models were generated. The tedious procedure of generating surface slab models from bulk structures was automated. The tools were used to study the high temperature surface corrosion resistance of a high-entropy alloy, Al10Nb15Ta5Ti30Zr40, and a nickel-based alloy, Ni70Nb10W20, under …
Analysis Of The Perspective On Syrian Refugees By Neighboring Countries, Norma Ghanem
Analysis Of The Perspective On Syrian Refugees By Neighboring Countries, Norma Ghanem
Theses and Dissertations
Mass migration destabilizes neighboring states, opening the way for fragile state exploitation by enemies, including those that could undermine U.S. national interests. This study investigates an area of the Levant region, specifically countries neighboring Syria, and analyzes their perspective on Syrian refugees for the time frame of 1 June 2019 - 30 June 2020. This analysis may assist in forming policy and creating strategies to address refugee related issues, both domestic and international. There are three main questions addressed. The first inspects dominant refugee framing, the second explores sentiment (dis)similarity within each country and across countries, and the third investigates …
Thermo-Fluidic Transport Process In A Novel M-Shaped Cavity Packed With Non-Darcian Porous Medium And Hybrid Nanofluid: Application Of Artificial Neural Network (Ann), Dipak Kumar Mandal, Nirmalendu Biswas, Nirmal K. Manna, Dilip Kumar Gayen, Rama S. R. Gorla, Ali J. Chamkha
Thermo-Fluidic Transport Process In A Novel M-Shaped Cavity Packed With Non-Darcian Porous Medium And Hybrid Nanofluid: Application Of Artificial Neural Network (Ann), Dipak Kumar Mandal, Nirmalendu Biswas, Nirmal K. Manna, Dilip Kumar Gayen, Rama S. R. Gorla, Ali J. Chamkha
Faculty Publications
In this work, an attempt has been made to explore numerically the thermo-fluidic transport process in a novel M-shaped enclosure filled with permeable material along with Al2O3-Cu hybrid nanoparticles suspended in water under the influence of a horizontal magnetizing field. To exercise the influence of geometric parameters, a classical trapezoidal cavity is modified with an inverted triangle at the top to construct an M-shaped cavity. The cavity is heated isothermally from the bottom and cooled from the top, whereas the inclined sidewalls are insulated. The role of geometric parameters on the thermal performance is scrutinized thoroughly …
Infrastructure Decision-Making Under Climate Change Uncertainty: Case Study Of Centralized Heating At Wright-Patterson Afb, Ohio, Tyler A. Ferry, Justin D. Delorit, Christopher M. Chini
Infrastructure Decision-Making Under Climate Change Uncertainty: Case Study Of Centralized Heating At Wright-Patterson Afb, Ohio, Tyler A. Ferry, Justin D. Delorit, Christopher M. Chini
Faculty Publications
Increased prevalence, lower cost, and reduced environmental impacts have granted natural gas status as a bridge fuel over the past decade in place of coal-fired heat and power generation across the United States. As a result, some coal facilities are retrofitting their systems to combust natural gas for heating and power. However, data and economic criteria surrounding these decisions are not widely available. Wright-Patterson Air Force Base (WPAFB) invested approximately $25 million, from 2014 to 2016, to retrofit two coal-fired steam-heat-generating plants with natural gas equipment. Economic analyses used to inform these long-term infrastructure decisions rarely consider the uncertainty of …
Computational Based Investigation Of Lattice Cell Optimization Under Uniaxial Compression Load, Derek G. Spear, Jeremiah S. Lane, Anthony N. Palazotto, Ryan A. Kemnitz
Computational Based Investigation Of Lattice Cell Optimization Under Uniaxial Compression Load, Derek G. Spear, Jeremiah S. Lane, Anthony N. Palazotto, Ryan A. Kemnitz
Faculty Publications
Structural optimization is a methodology used to generate novel structures within a design space by finding a maximum or minimum point within a set of constraints. Topology optimization, as a subset of structural optimization, is often used as a means for light-weighting a structure while maintaining mechanical performance. This article presents the mathematical basis for topology optimization, focused primarily on the Bi-directional Evolutionary Structural Optimization (BESO) and Solid Isotropic Material with Penalization (SIMP) methodologies, then applying the SIMP methodology to a case study of additively manufactured lattice cells. Three lattice designs were used: the Diamond, I-WP, and Primitive cells. These …
Applied Agile Digital Mission Engineering For Cislunar Space Domain Awareness, Benjamin R. Williams
Applied Agile Digital Mission Engineering For Cislunar Space Domain Awareness, Benjamin R. Williams
Theses and Dissertations
In the backdrop of an expansion into cislunar space and a digital transformation, the author synthesizes a methodology from agile system development, DE, ME, and MBSE processes, methods, and tools to develop a basic RA and DT for cislunar SDA mission and system design. The Agile DME methodology is used to conduct basic requirements analysis, develop a concept, understand cislunar physics, study scenario geometries, and perform analyses and the DT implements, executes, and accelerates research by integrating a descriptive tool with analytical and simulation tools. This research demonstrates the value of automated Modeling, Simulation, and Analysis (MSA) work flows and …
Potential Solution To Meet Growing Demands Of Refractory Metal: Selective Laser Melting Of Molybdenum-Tungsten Alloy, Jae Yu
Theses and Dissertations
Selective laser melting (SLM) of refractory metals has been of high interest in research due to the metals’ potential desirable characteristics in aeronautical and space applications. In particular, molybdenum and tungsten have been the focus of several studies in the search for high temperature and high strength purposes in applications like supersonic aircraft, re-entry vehicles, nuclear fission, power generation, and other space systems. However, there is still a significant knowledge gap to process defect-free alloys and making use of them in practical engineering functions. The aim of this study is to characterize the relationship between the microstructure and mechanical properties …
A Comparison Of Sporadic-E Occurrence Rates Using Gps Radio Occultation And Ionosonde Measurements, Rodney Carmona, Omar A. Nava, Eugene V. Dao, Daniel J. Emmons
A Comparison Of Sporadic-E Occurrence Rates Using Gps Radio Occultation And Ionosonde Measurements, Rodney Carmona, Omar A. Nava, Eugene V. Dao, Daniel J. Emmons
Faculty Publications
Sporadic-E (Es) occurrence rates from Global Position Satellite radio occultation (GPS-RO) measurements have shown to vary by a factor of five between studies, motivating the need for a comparison with ground-based measurements. In an attempt to find accurate GPS-RO techniques for detecting Es formation, occurrence rates derived using five previously developed GPS-RO techniques are compared to ionosonde measurements over an eight-year period from 2010–2017. GPS-RO measurements within 170 km of a ionosonde site are used to calculate Es occurrence rates and compared to the ground-truth ionosonde measurements. The techniques are compared individually for each ionosonde site …
Robust Error Estimation Based On Factor-Graph Models For Non-Line-Of-Sight Localization, O. Arda Vanli, Clark N. Taylor
Robust Error Estimation Based On Factor-Graph Models For Non-Line-Of-Sight Localization, O. Arda Vanli, Clark N. Taylor
Faculty Publications
This paper presents a method to estimate the covariances of the inputs in a factor-graph formulation for localization under non-line-of-sight conditions. A general solution based on covariance estimation and M-estimators in linear regression problems, is presented that is shown to give unbiased estimators of multiple variances and are robust against outliers. An iteratively re-weighted least squares algorithm is proposed to jointly compute the proposed variance estimators and the state estimates for the nonlinear factor graph optimization. The efficacy of the method is illustrated in a simulation study using a robot localization problem under various process and measurement models and measurement …
Academic Year 2021-2022 Faculty Excellence Showcase, Afit Graduate School Of Engineering & Management, Graduate School Of Engineering And Management, Air Force Institute Of Technology
Academic Year 2021-2022 Faculty Excellence Showcase, Afit Graduate School Of Engineering & Management, Graduate School Of Engineering And Management, Air Force Institute Of Technology
AFIT Documents
No abstract provided.
Graduate School Academic Catalog 2022-2023, Graduate School Of Engineering And Management, Air Force Institute Of Technology
Graduate School Academic Catalog 2022-2023, Graduate School Of Engineering And Management, Air Force Institute Of Technology
AFIT Documents
The Graduate Catalog represents the offerings, programs, and requirements in effect at the time of publication.
Effect Of Connection State & Transport/Application Protocol On The Machine Learning Outlier Detection Of Network Intrusions, George Yuchi, Torrey J. Wagner, Paul Auclair, Brent T. Langhals
Effect Of Connection State & Transport/Application Protocol On The Machine Learning Outlier Detection Of Network Intrusions, George Yuchi, Torrey J. Wagner, Paul Auclair, Brent T. Langhals
Faculty Publications
The majority of cyber infiltration & exfiltration intrusions leave a network footprint, and due to the multi-faceted nature of detecting network intrusions, it is often difficult to detect. In this work a Zeek-processed PCAP dataset containing the metadata of 36,667 network packets was modeled with several machine learning algorithms to classify normal vs. anomalous network activity. Principal component analysis with a 10% contamination factor was used to identify anomalous behavior. Models were created using recursive feature elimination on logistic regression and XGBClassifier algorithms, and also using Bayesian and bandit optimization of neural network hyperparameters. These models were trained on a …
Machine Learning Land Cover And Land Use Classification Of 4-Band Satellite Imagery, Lorelei Turner, Torrey J. Wagner, Paul Auclair, Brent T. Langhals
Machine Learning Land Cover And Land Use Classification Of 4-Band Satellite Imagery, Lorelei Turner, Torrey J. Wagner, Paul Auclair, Brent T. Langhals
Faculty Publications
Land-cover and land-use classification generates categories of terrestrial features, such as water or trees, which can be used to track how land is used. This work applies classical, ensemble and neural network machine learning algorithms to a multispectral remote sensing dataset containing 405,000 28x28 pixel image patches in 4 electromagnetic frequency bands. For each algorithm, model metrics and prediction execution time were evaluated, resulting in two families of models; fast and precise. The prediction time for an 81,000-patch group of predictions wasmodels, and >5s for the precise models, and there was not a significant change in prediction time when a …
Magneto-Exothermic Catalytic Chemical Reaction Along A Curved Surface, Muhammad Ashraf, Uzma Ahmad, Saqib Zia, Rama S. R. Gorla, Amnah S. Al-Johani, Ilyas Khan, Mulugeta Andualem
Magneto-Exothermic Catalytic Chemical Reaction Along A Curved Surface, Muhammad Ashraf, Uzma Ahmad, Saqib Zia, Rama S. R. Gorla, Amnah S. Al-Johani, Ilyas Khan, Mulugeta Andualem
Faculty Publications
In the current study, the physical behavior of the boundary layer flows along a curved surface owing exothermic catalytic chemical reaction, and the magnetic field is investigated. The mathematical model comprised of a part of momentum, energy, and mass equations, which are solved using a finite difference method along with primitive variable formulation. Numerical solutions, using the method of quantitative differentiation, are made with the appropriate choice of dimensionless parameters. Analysis of the results obtained shows that the field temperature and flow of fluids are strongly influenced by the combined effects of catalytic chemical reactions and the magnetic field. The …
Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors, Hengky Chandrahalim, Jonathan W. Smith
Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors, Hengky Chandrahalim, Jonathan W. Smith
AFIT Patents
A passive microscopic Fabry-Pérot Interferometer (FPI) sensor an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.
On The Synthesis Of Optimal Control Laws, Meir Pachter, Isaac E. Weintraub
On The Synthesis Of Optimal Control Laws, Meir Pachter, Isaac E. Weintraub
Faculty Publications
In this paper we advocate for Isaacs' method for the solution of differential games to be applied to the solution of optimal control problems. To make the argument, the vehicle employed is Pontryagin's canonical optimal control example, which entails a double integrator plant. However, rather than controlling the state to the origin, we correctly require the end state to reach a terminal set that contains the origin in its interior. Indeed, in practice, it is required to control to a prescribed tolerance rather than reach a desired end state; achieving tight tolerances is expensive, and from a theoretical point of …