Engineering Commons^™

Dynamics And Control Of Satellite Relative Motion In Proximity Operations, Mohamed Elsayed Aly Abd Elaziz Okasha

Mechanical & Aerospace Engineering Theses & Dissertations

In this dissertation, the development of relative navigation, guidance, and control algorithms of an autonomous space rendezvous and docking system are presented. These algorithms are based on innovative formulations of the relative motion equations that are completely explicit in time. The navigation system uses an extended Kalman filter based on these formulations to estimate the relative position and velocity of the chaser vehicle with respect to the target vehicle and the chaser attitude and gyro biases. This filter uses the range and angle measurements of the target relative to the chaser from a simulated LIDAR system, along with the star …

Near Earth Asteroid Mission Design For 2000 Sg344, Gökhan Çahşkan

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, methodologies and capabilities for mission trajectory design to asteroid 2000 SG344 are investigated. Design of orbital trajectories for interplanetary space flight requires application of principles from orbital mechanics including three dimensional orbital element description, orbit propagation, asteroid ephemerides, targeting logic, relative motion dynamics, and numerical algorithm implementation. The thesis research will attempt to assemble and integrate these various topics to achieve a general capability to conduct asteroid mission trajectory design. Further, appropriate methodology including selection of assumptions and models, computation process and flow, and design metrics and trades to achieve a practical and effective trajectory design process …

Evaluating Network Analysis And Agent Based Modeling For Investigating The Stability Of Commercial Air Carrier Schedules, Sheila Ruth Conway

Engineering Management & Systems Engineering Theses & Dissertations

For a number of years, the United States Federal Government has been formulating the Next Generation Air Transportation System plans for National Airspace System improvement. These improvements attempt to address air transportation holistically, but often address individual improvements in one arena such as ground or in-flight equipment.

In fact, air transportation system designers have had only limited success using traditional Operations Research and parametric modeling approaches in their analyses of innovative operations. They need a systemic methodology for modeling of safety-critical infrastructure that is comprehensive, objective, and sufficiently concrete, yet simple enough to be deployed with reasonable investment. The methodology …

Optimization Framework For A Radio Frequency Gun Based Injector, Alicia S. Hofler

Electrical & Computer Engineering Theses & Dissertations

Linear accelerator based light sources are used to produce coherent x-ray beams with unprecedented peak intensity. In these devices, the key parameters of the photon beam such as brilliance and coherence are directly dependent on the electron beam parameters. This leads to stringent beam quality requirements for the electron beam source. Radio frequency (RF) guns are used in such light sources since they accelerate electrons to relativistic energies over a very short distance, thus minimizing the beam quality degradation due to space charge effects within the particle bunch. Designing such sources including optimization of its beam parameters is a complex …

Exploring The Components Of Dynamic Modeling Techniques, Charles Daniel Turnitsa

Computational Modeling & Simulation Engineering Theses & Dissertations

Upon defining the terms modeling and simulation, it becomes apparent that there is a wide variety of different models, using different techniques, appropriate for different levels of representation for any one system to be modeled. Selecting an appropriate conceptual modeling technique from those available is an open question for the practitioner. Existing methods for describing techniques do not capture enough information about the expressive potential of those techniques such that an appropriate selection decision can be made. A formal method to describe conceptual modeling techniques that captures enough about the technique to distinguish it from others is identified as a …

Electrokinetic Transport Phenomena In Nanofluidic Devices, Mingkan Zhang

Mechanical & Aerospace Engineering Theses & Dissertations

Nanofluidic devices have wide potential applications in biology, chemistry and medicine, and have been proven to be very valuable in sensing biological particles (e.g., DNA and proteins) due to their efficiency, sensitivity and portability. Electrokinetic control of ion, fluid, and particle transport by using only electric field is the most popular method employed in nanofluidic devices. A comprehensive understanding of the electrokinetic ion, fluid, and particle transport in nanofluidics is essential for developing nanofluidic devices for the detection of single molecules, such as the next generation nanopore-based DNA sequencing technology. This research explored numerical simulation of electrokinetic ion and fluid …

An Investigation Into The Relationship Between An Engineering Manager's Purpose-Seeking Beliefs And Behaviors And The Engineering Manager's Perception Of Employee Creativity, Initiative And Purpose-Seeking Behavior, Charles Burton Daniels

Engineering Management & Systems Engineering Theses & Dissertations

Organizations have placed an overwhelming emphasis on extrinsic motivation of its workforce, normally in the form of financial incentives, in an attempt to assure individual and organizational high performance. While a significant level of financial resources is expended in this attempt to predict and influence employee behavior, no objective evidence exists of a favorable return of investment. In fact, the primary impact of most extrinsic motivation might actually be demotivation – the opposite of the intended use.

In this research the prevailing literature was examined and a conclusion about the power of both extrinsic and intrinsic motivation was synthesized to …

Agile Knowledge Management; A Review, Reconceptualization, And Extension To Military Applications, Dogan Ozturk

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research is to explore the conceptual background of agility in knowledge management, re-conceptualize it and extend it to military applications with a special focus on Counterinsurgency (COIN).

An initial qualitative exploration of agility in knowledge management was performed. Three different concepts and their interrelationships were analyzed: (1) knowledge management, (2) agility in operations, and (3) military organizations in the COIN environment. Findings from this initial qualitative analysis were used to inductively redefine, re-conceptualize and extend the concept of Agile Knowledge Management (AKM), as well as, to compare and adapt the AKM concept to the military environment …

Health Nexus: A Serious Game Prototype For Prevention And Treatment Of Obesity And Diabetes, Joseph C. Miller

Computational Modeling & Simulation Engineering Theses & Dissertations

Electronic games are a prevalent phenomenon of American culture and entertainment. Serious games are video games that take advantage of games' intrinsic entertaining and challenging characteristics for serious purposes, such as education, training, advertisement, and political campaigns. A significant number of serious games have been developed for a variety of diverse purposes. The last few years have witnessed the inception and growth of motion sensing technologies for games, including Nintendo Wii, Sony PlayStation Move, and Microsoft Kinect. These motion sensing technologies usually require game players' physical body movement in order to perform and achieve in the games, such as playing …

Earth Observation Time Estimates Using Curve Fitted Perturbed Orbit Tracks, Taner Gundogdu

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, time to observation for a generic perturbed low Earth orbit satellite, which is tasked, for reconnaissance of a given surface target is investigated. A curve fitting concept applied to past orbital track data is used to estimate and predict the overflight observation time. The least squares method is selected for the curve fitting process and used for both linear and non-linear aspects. Since orbital track data for actual spacecraft are not widely available, numerical integration of the governing motion equations is used as an alternate data source. One of the numerical integration methods, fourth-order Runge-Kutta, is used …

Model Verification For Multi-Body Dynamics And Six Degree Of Freedom Machine Impact Testing, Scott James Tedesco

Mechanical & Aerospace Engineering Theses & Dissertations

Using MSC's ADAMS software, a multi-body dynamic model was created to represent a Six Degree of Freedom (Six DOF) Machine, located at the Old Dominion University Dynamic Environment Simulation Laboratory (DES Lab). This rigid body model was verified for single axis impact using experimental test data from the Six DOF Machine. Due to the large number of unknowns in the physical Six DOF Machine, a parameter sensitivity study was conducted to analyze critical parameters. This study provided data regarding machine performance, improved general understanding of the physical and mechanical operation of the Six DOF Machine, and guidance for parameter modeling …

A Complete Autonomous Vehicle Solution: An Asv Case Study, Justin Michael Selfridge

Mechanical & Aerospace Engineering Theses & Dissertations

The field of robotics has grown at an astonishing rate over the past two decades, and the interest in autonomous vehicles has grown even faster. Autonomous vehicles offer the unique promise of removing drivers from dangerous environments, and increasing the efficiency of our highways. However, the development of these systems is no trivial task. For an autonomous vehicle to effectively navigate and interact with the world, the vehicle must ( 1) determine where it is located and create an accurate assessment of its surroundings, (2) develop a feasible navigational path based on the current surroundings and the vehicle's destination, and …

Effect Of Emergent Technologies On Aircraft Fuel Burn By Seat Class, Lee Matthew Watkins

Mechanical & Aerospace Engineering Theses & Dissertations

In this research, a set of advanced technologies collectively referred to as N+2 technologies, are applied to representative aircraft for seven different seat classes. This study will give a better understanding of which technologies will benefit aircraft of differing sizes compared to current studies which have focused on the fuel efficiency benefits of the N+1 technologies for one size of aircraft. Technologies applied consist of hybrid wing body (HWB) platforms, boundary layer ingestion (BLI) engines, weight reducing technologies, hybrid laminar flow control (HLFC) and advanced engine technologies. The aircraft are modeled in Flight Optimization System (FLOPS), a program developed at …

Design Of A Catenoidal Shaped Anechoic Termination, Kyle Myers

Masters Theses

An analytical model is developed in this thesis to predict the reflection coefficient of an anechoic termination consisting of a catenoidal horn connected to a tube lined with absorbing material. The theoretical predictions are compared to experimental measurements on a prototype. Comparisons are made for a variety of arrangements, including, an open horn, and a horn connected to absorbing terminations of two different lengths. The absorbing terminations are either open or closed to the environment and the analytical model can account for both these scenarios. The results indicate that the new model can accurately predict the reflection coefficient for each …

Quantifying The Impact Of Altered Hemodynamics And Vascular Biomechanics To Changes In Structure And Function In Native And Corrected Aortic Coarctation, Arjun Menon

Dissertations (1934 -)

Coarctation of the aorta (CoA) is associated with substantial cardiovascular morbidities despite successful treatment through surgical or catheter-based intervention. Although specific mechanisms leading to these morbidities remain elusive, abnormal hemodynamics and vascular biomechanics are implicated. We used a novel animal model that facilitates quantification of CoA-induced hemodynamic and vascular biomechanics alterations and their impact on vascular structure and function, independent of genetic or confounding factors. Rabbits underwent thoracic CoA at 10 weeks of age (~9 human years) to induce a 20 mmHg blood pressure (BP) gradient using permanent or dissolvable suture thereby replicating untreated and corrected CoA. Computational fluid dynamics …

Anaerobic Co-Digestion For Enhanced Renewable Energy And Green House Gas Emission Reduction, Navaneethan Navaratnam

Dissertations (1934 -)

The need to develop renewable energy is important for replacing fossil fuel, which is limited in quantity and also tends to increase in price over time. The addition of high strength organic wastes in municipal anaerobic digesters is growing and tends to increase renewable energy production. In addition, conversion of wastes to energy significantly reduces uncontrolled greenhouse gas emissions. Co-digestion of municipal sludge with any combination of wastes can result in synergistic, antagonistic or neutral outcomes. The objectives of this study were to identify potential co-digestates, determine synergistic, antagonistic and neutral effects, determine economic benefits, quantify performance of bench scale …

Concurrent Engineering Of Tolerance Synthesis And Process Selection For Products With Multiple Quality Characteristcs Considering Process Capability, Mohamad Imron Mustajib

Makara Journal of Technology

The existences of variances that are very difficult to be removed from manufacturing processes provide significance of tolerance to the product quality characteristics target of customer functional requirement. Furthermore, quality loss incurred due to deviation of quality characteristics of the target with a specified tolerance. This article discusses the development of concurrent engineering optimization model of tolerance design and manufacturing process selection on product with multiple quality characteristics by minimizing total costs in the system, namely total manufacturing cost and quality loss cost as functions of tolerance, also rework and scrap costs. The considered multiple quality characteristics have interrelated tolerance …

Modification Of Flow Structure Over A Van Model By Suction Flow Control To Reduce Aerodynamics Drag, Harinaldi Harinaldi, Budiarso Budiarso, Warjito Warjito, Engkos Achmad Kosasih, Rustan Tarakka, Sabar Pangihutan Simanungkalit, I Gusti Made Fredy Lay Teryanto

Makara Journal of Technology

Automobile aerodynamic studies are typically undertaken to improve safety and increase fuel efficiency as well as to find new innovation in automobile technology to deal with the problem of energy crisis and global warming. Some car companies have the objective to develop control solutions that enable to reduce the aerodynamic drag of vehicle and significant modification progress is still possible by reducing the mass, rolling friction or aerodynamic drag. Some flow control method provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled …

Optimizing Fermentation Medium To Produce Cyclosporin A Using Response Surface Methodology, Rofiq Sunaryanto

Makara Journal of Technology

Response surface methodology (RSM) is a three factorial model which illustrates the relationship between one or more independent variables. RSM can be used to optimize the fermentation medium for the production of Cyclosporin A from the isolate Tolypocladium inflatum. The optimal point of the response surface area is predicted by using a seconddegree polynomial model and applying the statistic model obtained from the central composite design (CCD). The results of optimizing the fermentation medium for Cyclopsorin using the three independent variables of glucose, casein, and KH2PO4 show that all three of the independent variables affect the production of Cyclosporin A. …

Engineering Innovation And Design For Stem Teachers And The Stem Quality Framework, James Rowley, Sandi Preiss, Margaret Pinnell, Suzanne Franco

Mechanical and Aerospace Engineering Faculty Publications

The backbone of economic growth in the United States relies on engineering innovation. However, engineering innovation cannot occur without engineers and scientists. Unfortunately however, many K-12 students do not have a good understanding of the engineering design process or the vast field of engineering. As a result, many students lose interest in math and science and do not pursue Science, Technology, Engineering and Math (STEM) fields. This paper will describe a unique partnership among the Teacher Education Program and School of Engineering at the University of Dayton (UD) and the Dayton Regional STEM Center (DRSC). This partnership initiated with the …

Soil Greenhouse Gas Emissions In The Life Cycle Assessment Of Cellulosic Ethanol From Crop Residue, Xiao Xue Fang

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Concerns about climate change and the increasing cost of fossil fuels have led to interest in the development of renewable biofuel pathways for reducing greenhouse gas (GHG) emissions. The use of corn residue as a potential source of biomass feedstock for cellulosic ethanol production has been favored as cost effective. Previous research has shown that crop residue removal can cause a loss of soil organic carbon (SOC), which potentially is a source of GHG emissions in the form of CO₂. Using a life cycle assessment (LCA) approach, this study investigated the impact of corn residue removal on total …

Reducing The Radiation Dose To Women Receiving Cardiac Ct Scans, Michael Hoppe

Master's Theses (2009 -)

This thesis aims to quantify the reduction in radiation dose deposited in glandular breast tissue achieved by using tilted gantry acquisition during cardiac CT scans. Previous work by Halpern et al. suggested using tilted acquisition parallel to the long axis of the patient’s heart. However, for a larger portion of the population this is not feasible due to the design of current scanners (which are limited to maximum tilt angles of 30 degrees). This study investigated the potential dose reduction and image quality effects at commercially available tilt angles between 0-30 degrees through simulation and experimental studies.

Upon IRB approval, …

Abnormal Neuromuscular Fatigue And Motor Performance Of The Knee Extensors Post Stroke, Henry Kuhnen

Master's Theses (2009 -)

Stroke causes paresis in leg muscles, such as the knee extensors, that significantly impairs motor control and function during tasks such as walking. Reduced endurance and increased kinematic asymmetries during walking over time indicate paretic musculature may fatigue more quickly than non-paretic musculature. The primary purpose of this study was to identify abnormalities in neuromuscular fatigue (reduction in force over time) of the paretic knee extensors and associate them with motor performance.

We investigated the effects of repeated six second isometric submaximal (30% of maximum voluntary contraction) knee extensor fatiguing contractions on task failure and motor performance in ten chronic …

Detection And Analysis Of Sludge Bulking Events Using Data Mining And Machine Learning Approach, Yuanhao Zhao

Master's Theses (2009 -)

Sludge bulking is the most notable cause of activated sludge plant failure (i.e. exceeding discharge permit quality limits) worldwide. Numerous mathematical methods have been applied to detect and provide warning for the prevention of sludge bulking. However, these models often fail to reliably forecast sludge bulking events because they focus on the point-by-point "curve-fitting" strategy, while the number of bulking event data points is relatively small in comparison with the large amount of data in the time series. Therefore, three machine learning approaches which focus on detecting the temporal pattern data before the sludge bulking events are considered in this …

Analytical Prediction Of Crosstalk Among Vias In Multilayer Printed Circuit Boards, Songping Wu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Crosstalk among vias is a significant problem in high-speed multilayer printed circuit boards (PCBs), deteriorating signal quality and increasing jitter, especially when circuit density is high. in this paper, a two-step via crosstalk evaluation procedure is proposed. a fast approach for crosstalk estimation is developed for net screening as the first step. Then, more accurate but more time-consuming modeling can be performed for critical nets or the problematic nets identified in the screening. the main contribution of this study includes the analytical prediction of crosstalk among vias based on an infinite parallel-plane assumption. its effectiveness and efficiency to predict the …

Assurance Of Energy Efficiency And Data Security For Ecg Transmission In Basns, Tao Ma, Pradhumna Shrestha, Michael Hempel, Dongming Peng, Hamid Sharif, Hsiao-Hwa Chen

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

With the technological advancement in body area sensor networks (BASNs), low cost high quality electrocardiographic (ECG) diagnosis systems have become important equipment for healthcare service providers. However, energy consumption and data security with ECG systems in BASNs are still two major challenges to tackle. In this study, we investigate the properties of compressed ECG data for energy saving as an effort to devise a selective encryption mechanism and a two-rate unequal error protection (UEP) scheme. The proposed selective encryption mechanism provides a simple and yet effective security solution for an ECG sensor-based communication platform, where only one percent of data …

Peridynamic Model For Dynamic Fracture In Unidirectional Fiber-Reinforced Composites, Wenke Hu, Youn Doh Ha, Florin Bobaru

Department of Mechanical and Materials Engineering: Faculty Publications

We propose a computational method for a homogenized peridynamics description of fiber-reinforced composites and we use it to simulate dynamic brittle fracture and damage in these materials. With this model we analyze the dynamic effects induced by different types of dynamic loading on the fracture and damage behavior of unidirectional fiber-reinforced composites. In contrast to the results expected from quasi-static loading, the simulations show that dynamic conditions can lead to co-existence of and transitions between fracture modes; matrix shattering can happen before a splitting crack propagates. We observe matrix–fiber splitting fracture, matrix cracking, and crack migration in the matrix, including …

First Long-Term, Direct Measurements Of Evapotranspiration And Surface Water Balance In The Nebraska Sandhills, David P. Billesbach, Timothy J. Arkebauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Nebraska SandHills is a vast grassland ecoregion that also serves as the main recharge zone for the High Plains (Ogallala) aquifer. Despite the national importance of this region in supplying irrigation water and supporting the US cattle industry, there have, until now, been no long-term, direct measurements of the components of the surface water balance. We have addressed this issue by installing energy balance/Bowen ratio (EBBR) flux towers in three key ecosystems. We report here the results of 7 years of measurements and interpret them in terms of annual weather variability. Additionally, these data have allowed us to make …

Evaluation Of The Bank Stability And Toe Erosion Model (Bstem) For Predicting Lateral Retreat On Composite Streambanks, Taber L. Midgley, Garey A. Fox, Derek M. Heeren

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Streambank erosion is known to be a major source of sediment in streams and rivers. The Bank Stability and Toe Erosion Model (BSTEM) was developed in order to predict streambank retreat due to both fluvial erosion and geotechnical failure. However, few, if any, model evaluations using long-term streambank retreat data have been performed. The objectives of this research were to (1) monitor long-term composite streambank retreat during a hydraulically active period on a rapidly migrating stream, (2) evaluate BSTEM’s ability to predict the measured streambank retreat, and (3) assess the importance of accurate geotechnical, fluvial erosion, and near-bank pore-water pressure …

Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma, Lelitha Vanajakshi, V. Girish, M. S. Harshitha

Department of Civil and Environmental Engineering: Faculty Publications

Signalized intersections are provided in traffic networks to improve the safety and efficiency of vehicular and pedestrian movement. There are various measures under education, enforcement and engineering headings that are being attempted to improve safety and efficiency of operations at a signalized intersection. Provision of signal countdown timer, a timer showing the remaining red and green time in a phase, is one such measure and is commonly adopted in India. However, studies on effects of countdown timer under Indian traffic conditions are very scarce. Traffic heterogeneity and lack of lane discipline makes transferability of models developed in other countries (with …