Engineering Commons^™

Designing An On-Demand Dynamic Crowdshipping Model And Evaluating Its Ability To Serve Local Retail Delivery In New York City, Shirin Najaf Abadi

Dissertations and Theses

Nowadays city mobility is challenging, mainly in populated metropolitan areas. Growing commute demands, increase in the number of for-hire vehicles, enormous escalation in several intra-city deliveries and limited infrastructure (road capacities), all contribute to mobility challenges. These challenges typically have significant impacts on residents’ quality-of-life particularly from an economic and environmental perspective. Decision-makers have to optimize transportation resources to minimize the system externalities (especially in large-scale metropolitan areas). This thesis focus on the intra-city mobility problems experienced by travelers (in the form of congestion and imbalance taxi resources) and businesses (in the form of last-mile delivery), while taking into consideration …

Optimum Design Of Axial Flux Pm Machines Based On Electromagnetic 3d Fea, Narges Taran

Theses and Dissertations--Electrical and Computer Engineering

Axial flux permanent magnet (AFPM) machines have recently attracted significant attention due to several reasons, such as their specific form factor, potentially higher torque density and lower losses, feasibility of increasing the number of poles, and facilitating innovative machine structures for emerging applications. One such machine design, which has promising, high efficiency particularly at higher speeds, is of the coreless AFPM type and has been studied in the dissertation together with more conventional AFPM topologies that employ a ferromagnetic core.

A challenge in designing coreless AFPM machines is estimating the eddy current losses. This work proposes a new hybrid analytical …

Design And Process Of 3d-Printed Parts Using Composite Theory, Jordan Garcia

Theses and Dissertations--Mechanical Engineering

3D printing is a revolutionary manufacturing method that allows the productions of engineering parts almost directly from modeling software on a computer. With 3D printing technology, future manufacturing could become vastly efficient. However, it is observed that the procedures used in 3D printing differ substantially among the printers and from those used in conventional manufacturing. In this thesis, the mechanical properties of engineering products fabricated by 3D printing were comprehensively evaluated and then compared with those made by conventional manufacturing. Three open-source 3D printers, i.e., the Flash Forge Dreamer, the Tevo Tornado, and the Prusa, were used to fabricate the …

Optimization Of Underbody Blast Energy-Attenuating Seat Mechanisms Using Modified Madymo Hybrid Iii And Human Body Models, Kelly Erin Bryan Bosch

Wayne State University Dissertations

Energy attenuating (EA) blast seats, although not new to the market, have not been fully characterized with respect to energy attenuation capability and the resulting effects on occupant protection. EA seats utilize stroking mechanisms to absorb energy and reduce the vertical forces imparted on the occupant’s pelvis and lower spine complex. Although a variety of EA seats are available on the market, the fundamental question behind how to optimize the force and deflection rates of the EA mechanisms to effectively reduce occupant injury has not yet been answered. Using modeling and simulation techniques, this research developed a tool to determine …

Multi-Objective Optimization Mission Design For Small-Body Coverage Missions, David William Hinckley

Graduate College Dissertations and Theses

Missions concerning small-body celestial objects are of growing interest due to the resources and information they can provide. Such missions require detailed information about the surface of the body for interactions, such as landing on the surface, as well as predicting the gravity field of the object. This work provides a means of optimizing the mission elements of trajectory and imaging target schedules so that the level of knowledge of the surface can be increased. The information required to increase one's knowledge of the surface is described as a set of conditions placed on the collection of images taken of …

Safe And Efficient Intelligent Intersection Control Of Autonomous Vehicles, Qiang Lu

Electronic Theses and Dissertations

In this dissertation, we address a problem of safe and efficient intersection crossing traffic management of autonomous and connected ground traffic. Toward this objective, we propose several algorithms to handle different traffic environments. First, an algorithm that is called the Discrete-time occupancies trajectory (DTOT) based Intersection traffic Coordination Algorithm (DICA) is proposed. All vehicles in the system are Connected and Autonomous Vehicles (CAVs) and capable of wireless Vehicle-to-Intersection communication. The main advantage of DICA is that it enables us to utilize the intersection space more efficiently resulting in less delay for vehicles to cross the intersection. In the proposed framework, …

Optimal Power Flow Control Of Networked Dc Microgrids, Eddy H. Trinklein

Dissertations, Master's Theses and Master's Reports

The US military is moving toward the electrification of many weapon systems and platforms. Advanced weapon systems such as high energy radar, electro-magnetic kinetic weapons and directed energy pose significant integration challenges due to their pulsed power electrical load profile. Additionally, the weapons platforms, including ships, aircraft, and vehicles can be studied as a mobile microgrids with multiple generation sources, loads, and energy storage. There is also a desire to extend the mission profile and capabilities of these systems. Common goals are to increase fuel efficiency, maintaining system stability, and reduce energy storage size as typically required to enable pulsed …

Optimization And Control Of Arrays Of Wave Energy Converters, Jianyang Lyu

Dissertations, Master's Theses and Master's Reports

Wave Energy Converter Array is a practical approach to harvest ocean wave energy. To leverage the potential of the WEC array in terms of energy extraction, it is essential to have a properly designed array configuration and control system. This thesis explores the optimal configuration of Wave Energy Converters (WECs) arrays and their optimal control. The optimization of the WEC array allows both dimensions of individual WECs as well as the array layout to varying. In the first optimization problem, cylindrical buoys are assumed in the array where their radii and drafts are optimization parameters. Genetic Algorithms are used for …

Curricular Optimization: Solving For The Optimal Student Success Pathway, William G. Thompson-Arjona

Theses and Dissertations--Electrical and Computer Engineering

Considering the significant investment of higher education made by students and their families, graduating in a timely manner is of the utmost importance. Delay attributed to drop out or the retaking of a course adds cost and negatively affects a student’s academic progression. Considering this, it becomes paramount for institutions to focus on student success in relation to term scheduling.

Often overlooked, complexity of a course schedule may be one of the most important factors in whether or not a student successfully completes his or her degree. More often than not students entering an institution as a first time full …

Applications Of A New Genetic Algorithm To Solve The Centralized Carrier Collaboration And Multihub Location Problem Considering Environmental Impacts, Eduardo Jose Castillo Fatule

Open Access Theses & Dissertations

The Centralized Carrier Collaboration and Multi-hub Location Problem (CCCMLP) represents a strategy that small-to-medium sized less-than-truckload (LTL) carrier companies can use in order to improve their profit margins. It is a strategy that is being explored in order to make these companies more sustainable as they are forced to reinvent their processes and supply chains. In this work, I will present a metaheuristic approach to optimizing their hub establishment and routing policies in order to better their expected profit margins and reduce their environmental impacts. The study considers the costs of transportation, loading and unloading, maintenance, operations, and inventory holding …

Time-Dependent Reliability Methodologies With Saddlepoint Approximation, Zhangli Hu

Doctoral Dissertations

"Engineers always encounter time-dependent uncertainties that ubiquitously exist, such as the random deterioration of material properties and time-variant loads. Therefore the reliability of engineering systems becomes time-dependent. It is crucial to predict the time-dependent reliability in the design stage, given possible catastrophic consequences of a failure. Although extensive research has been conducted on reliability analysis, estimating the reliability accurately and efficiently is still challenging. The objective of this work is to develop accurate and efficient reliability methodologies for engineering design. The basic idea is the integration of traditional reliability methods with saddlepoint approximation (SPA), which can accurately approximate the tail …

Techno-Economic Optimization And Environmental Life Cycle Assessment Of Microgrids Using Genetic Algorithm And Artificial Neural Networks, Prashant Nagapurkar

Doctoral Dissertations

"This dissertation focuses primarily on techno-economic optimization and environmental life cycle assessment (LCA) of sustainable energy generation technologies. This work is divided into five papers. The first paper discusses the techno-economic optimization and environmental life cycle assessment of microgrids located in the USA using genetic algorithm. In this paper, a methodology was developed that assessed the techno-economic and environmental performance of a small scale microgrid located in US cities of Tucson, Lubbock and Dickinson. Providing uninterrupted power the microgrid was composed of seven components -- solar photovoltaics, wind-turbines, lead acid batteries, biodiesel generators, fuel cells, electrolyzers and H₂ tanks. …

Renewables-Integrated Internal Combustion Engine-Based Multi-Generation Options For Uab Buildings, Qing Mu

All ETDs from UAB

Distributed energy, also district or decentralized energy is generated or stored by a variety of small, grid-connected devices referred to as distributed energy resources, or distributed energy resource systems. The Distributed Generation (DG) systems can increase energy system reliability, reduce peak power requirements, and improve energy infrastructure resilience. In this study, a DG system using renewable energy sources and energy storage has been introduced for the whole University of Alabama at Birmingham (UAB) campus. The energy sources for this DG system are photovoltaic arrays, a natural-gas-powered Internal Combustion Engine (ICE), and wind turbines. The energy storage component used in this …

Non-Deterministic Metamodeling For Multidisciplinary Design Optimization Of Aircraft Systems Under Uncertainty, Daniel L. Clark Jr.

Browse all Theses and Dissertations

To make coupled multi-physics-informed design decisions, multidisciplinary analysis, design optimization and uncertainty quantification must be present to accurately represent the full system under investigation. Unfortunately, all of these processes are computationally demanding, requiring a large number of system evaluations with identified uncertain variables, and iterative system evaluations with respect to the design variables of interest. Surrogate or metamodels are used to alleviate the computational burden in both these design exploration activities by trading accuracy with efficiency. The primary objective of this dissertation is to develop a flexible surrogate modeling technique capable of quantifying the uncertainty of multidisciplinary systems in an …

Strategic Decision Facilitation: An Exploration Of Alternative Anchoring And Scale Distortion Optimization In Multi-Attribute Group Decision Making, Joseph Patrick Kristbaum

Browse all Theses and Dissertations

Choosing between alternatives, regardless of the decision context in an organizational group setting is a difficult task. The integrity of the decision is under constant scrutiny and rarely are we ever able to characterize the magnitude of that with which we are consciously or subconsciously concerned: personal bias. This leads to long, drawn out timelines and loosely trusted decisions. This dissertation research focuses on using a traditionally, negatively viewed anchoring bias strategically in a series of experiments with a hypothesis that it can be used to positively reduce personal biases such as preference bias and judgement rooted in ambiguous or …

Sparsity Constrained Inverse Problems - Application To Vibration-Based Structural Health Monitoring, Chandler B. Smith

Graduate College Dissertations and Theses

Vibration-based structural health monitoring (SHM) seeks to detect, quantify, locate, and prognosticate damage by processing vibration signals measured while the structure is operational. The basic premise of vibration-based SHM is that damage will affect the stiffness, mass or energy dissipation properties of the structure and in turn alter its measured dynamic characteristics. In order to make SHM a practical technology it is necessary to perform damage assessment using only a minimum number of permanently installed sensors. Deducing damage at unmeasured regions of the structural domain requires solving an inverse problem that is underdetermined and(or) ill-conditioned. In addition, the effects of …