Engineering Commons^™

Truss Bridge Damage Localization And Severity Estimation Using Influence Lines, Hamoud Alshallaqi

Civil and Environmental Engineering Theses and Dissertations

The safety of bridges is one of the primary concerns of researchers, engineers, and bridge owners and managers, especially when bridges are approaching the end of their intended service lives. The estimation of bridge condition and remaining service life is critical to prioritize the allocation of available funding for repairs and rehabilitation. Various methods, including both dynamic and static approaches, have been developed to detect and localize bridge damage and estimate its severity. This research presents a methodology for detecting a single damaged member in a truss bridge and estimating the severity of the damage using static vertical deflection influence …

Enhanced Security Utilizing Side Channel Data Analysis, Michael Taylor

Computer Science and Engineering Theses and Dissertations

The physical state of a system is affected by the activities and processes in which it is tasked with carrying out. In the past there have been many instances where such physical changes have been exploited by bad actors in order to gain insight into the operational state and even the data being held on a system. This method of side channel exploitation is very often effective due to the relative difficulty of obfuscating activity on a physical level. However, in order to take advantage of side channel data streams one must have a detailed working knowledge of how a …

Developing Iot-Based Geophysical Micro-Observatories Utilizing Cloud Computing, Joshua Sylvester

Computer Science and Engineering Theses and Dissertations

Instrumentation for collecting geophysical data, specifically heat flow, in lake and marine environments has been in existence for over fifty years. Despite this, the costs associated with data collection and the technological limitations of existing instrumentation can be preventative when conducting geophysical studies. Furthermore, the success rate of such studies is limited by the lack of real time data transmission capabilities when instruments are deployed for extended periods of time. As a solution to this problem we have created cost-effective and lightweight IoT-driven instrumentation and combined it with cloud computing technology facilitating real time data transmission to the cloud. Furthermore, …

Machine Learning Approach To Stability Analysis Of Semiconductor Memory Element, Ravindra Thanniru, Gautam Kapila, Nibhrat Lohia

SMU Data Science Review

Memory stability analysis traditionally relied heavily on circuit simulation-based approaches that run Monte Carlo (MC) analysis over various manufacturing and use condition parameters. This paper researches application of Machine Learning approaches for memory element failure analysis which could mimic simulation-like accuracy and minimize the need for engineers to rely heavily on simulators for their validations. Both regressor and classifier algorithms are benchmarked for accuracy and recall scores. A high recall score implies fewer escapes of fails to field and is the metric of choice for comparing algorithm. The paper identifies that recall score in excess of 0.97 can be achieved …

Modeling Electric Energy Generation In Ercot During Extreme Weather Events And The Impact Renewable Energy Has On Grid Reliability, Adam R. Ruthford, Bivin Sadler

SMU Data Science Review

This paper shows the inadequacy of current grid backup supplies, their ongoing threat to grid reliability, and the increased risk of customer blackouts. This paper also examines reliability concerns caused by renewable energy sources under more normal operating conditions. This paper seeks to model the impacts of extreme weather on ERCOTs grid. Unusual weather patterns require that the electrical grid operates in conditions outside normal operating parameters. Electrical system demand can spike well above normal levels. At the same time, weather influences can change the operating envelope of electrical generation equipment. The ERCOT grid has changed from its’ traditional mix …

Liquid-Vapor Distributions In Evacuated Small Diameter Channels For Improved Accuracy Of Initial Conditions In Modeling Of Oscillating Heat Pipes, Travis Mayberry

Mechanical Engineering Research Theses and Dissertations

Oscillating heat pipes, also known as pulsating heat pipes, are increasingly becoming a preferred high-performance thermal ground plane in a variety of heat spreading applications due to a number of advantages over traditional copper-water wicked heat pipes, including their lighter weight, thinner profiles, simpler fabrication, and greater variety of material and working fluid options. A major barrier to even wider adoption, however, is the lack of comprehensive analytical models to simulate their performance. A key input to first principles models simulating the fundamental physics of the devices is the initial condition of liquid and vapor segment lengths and their distribution …

Characterization Of Uav-Based Wireless Channels With Diverse Antenna Configurations, Mahmoud Badi

Electrical Engineering Theses and Dissertations

In the next wave of swarm-based applications, unmanned aerial vehicles (UAVs) need to communicate with peer drones in any direction of a three-dimensional (3D) space. On a given drone and across drones, various antenna positions and orientations are possible. We know that, in free space, high levels of signal loss are expected if the transmitting and receiving antennas are cross polarized. However, increasing the reflective and scattering objects in the channel between a transmitter and receiver can cause the received polarization to become completely independent from the transmitted polarization, making the cross-polarization of antennas insignificant. Usually, these effects are studied …

Exploring Neural Networks For Predicting Sentinel-C Backscatter Between Image Acquisitions, Zhongdi Wu

Computer Science and Engineering Theses and Dissertations

Measuring moisture dynamics in soil and overlying vegetation is key to understanding ecosystem and agricultural dynamics in many contexts. For many applications, moisture information is demanded at high temporal frequency over large areas. Sentinel-1 C-band radar backscatter satellite images provide a repeating sequence of fine-resolution (10-m) observations that can be used to infer soil and vegetation moisture, but the 12-day interval between satellite observations is infrequent relative to the sensed moisture dynamics. Machine learning approaches have been used to predict soil moisture at higher spatial resolutions than the original satellite images, but little effort has been made to increase the …

Using A Light-Based Power Source To Defeat Power Analysis Attacks, Remus Valentin Tumac

Computer Science and Engineering Theses and Dissertations

Power analysis attacks exploit the correlation between the information processed by an electronic system and the power consumption of the system. By powering an electronic system with an optical power source, we can prevent meaningful information from being leaked to the power pins and captured in power traces. The relatively constant current draw of the optical power source hides any variability in the power consumption of the target system caused by the logic gates' switching activity of the system as observed at the power pins. This thesis will provide evidence to show that using an optical power source should make …

A Methodology For Reliability-Based Selection Of System Of Systems, Justin Brown

Operations Research and Engineering Management Theses and Dissertations

Currently, Department of Defense (DoD) systems underperform and have inadequate reliability compared to acquisition expectations. Additionally, System of Systems (SoS) complexity and non-quantifiable approaches to selecting systems to perform a mission cause challenges for the decision-maker. Beyond DoD, mission-critical scenarios exist where responses are not data-driven, such as hurricane response, wildfire response, and littoral search and research missions. Optimization of these missions within a short amount of time can not only increase the probability of success and reduce the cost of performing the mission but allow systems to be used for additional missions.

This dissertation presents solution methodologies to address …

Infrastructure Deficiency Correlation With Pedestrian/Cyclist Crashes: A Data-Driven Approach, Farbod Tavakkoli Khomeini, Barbara Minsker, Michael Hahler, Janille Smith-Colin, Xinlei Wang

Civil and Environmental Engineering Theses and Dissertations

A model for identifying the impacts of infrastructure deficiency on road traffic safety is needed to help governments prioritize strategic investments to increase public safety. During the 2010-2019 period, U.S. pedestrian and cyclist fatalities rose by 44% and 36%, respectively, and previous studies have shown a positive correlation between pedestrian/cyclist crashes and low-income areas. To our knowledge, this study is the first to investigate further the reasons behind the higher probability of pedestrian and cyclist crashes in low-income areas. The proposed hypothesis is that the higher probability of pedestrian and cyclist crashes in low-income areas correlates with higher infrastructure deficiencies …

A Restrained Beam Sub-Model Assembly (Rbsa) For Progressive Collapse Analysis, Muath Alhumaidi

Civil and Environmental Engineering Theses and Dissertations

The progressive collapse failure mode occurs in buildings when a load-carrying element is lost due to extreme events such as explosions caused by terrorist attacks or vehicular impacts. Guidelines and many researches efforts have been established in order to limit and prevent total collapse of buildings after losing a load-carrying component (e.g., a column). Two famous examples of progressive collapse are the 1968 Ronan Point apartment building kitchen explosion on the 18^th floor and the 1995 Alfred P. Murrah Federal Building bombing in Oklahoma City. Both examples resulted in fatalities and injuries. A small number of these …

Geometrically Complex Planar Heat Exchangers, Derli Dias Do Amaral Junior, Jose Lage

Mechanical Engineering Research Theses and Dissertations

In this study, geometrically complex planar heat exchangers, designed in line with the Constructal Law and operating at steady-state, are investigated numerically. The work is divided into two parts, one focusing on diffusion heat transfer in a rectangular plane and another on conjugate diffusion-convection heat transfer in a circular plane heat exchanger.

In the first part, a heat generating rectangular solid volume made of a low conductivity material is cooled through a small, isothermal side-section of the domain. The diffusion cooling process is improved by distributing within the heat generating material a fixed amount of a high conductivity material. The …

Reducing Power During Manufacturing Test Using Different Architectures, Yi Sun

Computer Science and Engineering Theses and Dissertations

Power during manufacturing test can be several times higher than power consumption in functional mode. Excessive power during test can cause IR drop, over-heating, and early aging of the chips. In this dissertation, three different architectures have been introduced to reduce test power in general cases as well as in certain scenarios, including field test.

In the first architecture, scan chains are divided into several segments. Every segment needs a control bit to enable capture in a segment when new faults are detectable on that segment for that pattern. Otherwise, the segment should be disabled to reduce capture power. We …

Response Modification And Seismic Protection Of Yielding Structures Equipped With Inerters And Hysteretic Dampers, Gholamreza Moghimi

Civil and Environmental Engineering Theses and Dissertations

This study investigates the seismic response of structures with sustainable, long-stroke response modification devices. The main thrust of the dissertation is the investigation of the seismic response of yielding structures equipped with supplemental rotational inertia, or inerters. The last chapter of this dissertation investigates the seismic response of multistory yielding steel structures equipped with pressurized sand dampers.

Inerters are mechanical devices with resisting force proportional to the relative acceleration of their end nodes. This class of response modification devices complements the traditional fluid viscous damping devices with resisting force proportional to the relative velocity at their end-nodes. Mass-amplification is the …

Anisotropic Plasticity Modeling Of Thin Sheets And Its Application To Micro Channel Forming Of Steel Foils, Jie Sheng

Mechanical Engineering Research Theses and Dissertations

Thin sheet metals and ultrathin metal foils produced by industrial rolling processes are textured polycrystalline materials and their mechanical behaviors may depend strongly on the orientation of applied loading. Consideration of such plastic anisotropy in advanced modeling of these materials is of the paramount importance in designing optimal manufacturing processes for automotive and other applications using finite element methods. This research addresses several critical issues in anisotropic plasticity modeling and its applications in analyzing micro channel forming of ultrathin stainless-steel foils. An experimental study has first been carried out on the accuracy and sensitivity of measuring the plastic strain ratios …

Electricity Market Operations With Massive Renewable Integration: New Designs, Shengfei Yin

Electrical Engineering Theses and Dissertations

Electricity market has been transitioning from a conventional and deterministic operation to a stochastic operation under the increasing penetration of renewable energy. Industry-level solutions toward the future electricity market operation ask for both accuracy and efficiency while maintaining model interpretability. Hence, reliable stochastic optimization techniques come to the first place for such a complex and dynamic problem.

This work starts at proposing a solution strategy for the uncertainty-based power system planning problem, which acts as a preliminary and instructs the electricity market operation. Considering 100% renewable penetration in the future, it analyzes the cost-effectiveness of renewable energy from a long-term …

Magnetic Gradient-Based Magnetic Tweezer System For 3d And Swarm Control Of Microswimmer, Xiao Zhang

Mechanical Engineering Research Theses and Dissertations

Microscale manipulation has very promising potential in medical applications such as drug delivery, minimal and invasion surgery. Contactless control is preferable as remote manipulation is necessary for in vivo applications. Among different control methods, magnetic power source is more suitable and robust for the applications mentioned above. Presented here is a magnetic tweezer system, which manipulates microscale magnetic particles using magnetic forces created by magnetic field gradient. The proposed system has three advantages: First, force applied by the magnetic tweezer system does not contact with the target object and can be generated in different directions. Second, the magnetic tweezer system …

Context-Aware Sensing And Fusion For Structural Health Monitoring And Night Time Traffic Surveillance, Xinxiang Zhang

Electrical Engineering Theses and Dissertations

Rapid developments in computer vision technologies have been transforming many traditional fields in engineering and science in the last few decades, especially in terms of diagnosing problems from visual images. Leveraging computer vision technologies to inspect, monitor, assess infrastructure conditions, and analyze traffic dynamics, has gained significant increase in both effectiveness and efficiency, compared to the cost of traditional instrumentation arrays to monitor, and manually inspect civil infrastructures and traffic conditions. Therefore, to construct the next-generation intelligent civil and transportation infrastructures, this dissertation develops a comprehensive computer-vision based sensing and fusion framework for structural health monitoring and intelligent transportation systems. …

Characterization Of Landslide Processes From Radar Remote Sensing And Hydromechanical Modeling, Yuankun Xu

Earth Sciences Theses and Dissertations

Landsides are a natural geomorphic process yet a dangerous hazard which annually causes thousands of casualties and billions of property loss in a global scale. Understanding landslide motion kinematics from early initiation to final deposition is critical for monitoring, assessing, and forecasting landslide movement in order to mitigate their hazards. Landslides occur under diverse environmental settings and appear in variable types; however, all types of landslides can be mechanically attributed to shearing failure at the basal surface due to stress regime shift contributed by internal and/or external forcing. Typical internal factors include soil/rock weathering, whereas typical external triggering forces encompass …

Rehology And Electrical Conductivity Of Particulate Composites In Additive Manufacturing, Bin Xia

Mechanical Engineering Research Theses and Dissertations

Extrusion-based multi-functional additive manufacturing (AM) has been a rapidly developing area in AM recently. Particulate composites are widely used in this area to provide different functionalities with different types of particulate additives. However, there is no systematic understanding of the behavior of particulate composites during extrusion (especially in small nozzles) or of their properties once deposited in the build. This work investigates the properties of the type of particulate composites usually used in additive manufacturing, composed of a polymer matrix material and particulate additives within the micrometer scale. The focus is on the material rheology in the nozzle/capillary (for the …

Characterization Of An Urban Watershed: The Case For Rowlett Creek Watershed Impaired By Bacteria And Nutrient Concerns, Heather Firn

Civil and Environmental Engineering Theses and Dissertations

Firn, Heather B.S., Southern Connecticut State University, 2009 M.S., Southern Connecticut State University, 2013

Characterization of an Urban Watershed: The Case

for Rowlett Creek Watershed Impaired by Bacteria

and Nutrient Concerns

Advisor: Professor Wenjie Sun

Master of Science conferred May, 15, 2021

Thesis completed April, 27, 2021

Water quality and its relationship with urbanization is one of many nationwide environmental concerns. Rowlett Creek is located in an urban watershed in the Dallas-Fort Worth Metroplex. Since 2014, it has been listed by the Texas Commission on Environmental Quality as impaired for bacteria and as a screening limit concern for nitrate. Water …

Actuation And Control Methods For Individual And Swarm Multiscale Mechanical Systems, Pouria Razzaghi

Mechanical Engineering Research Theses and Dissertations

Robotic mechanisms can be driven by different internally and externally applied inertial and magnetic actuations. These actuations are utilized to regulate the dynamics of robots and move them in different locomotion modes. The first part of this dissertation is about using an external magnetic actuation to move a simple-in-design, small-scale robot for biomedical applications. The robots can be steered in different locomotion modes such as pivot walking and tumbling. The control design of this system consists of a swarm algorithm under a global control input, and a vision-based closed-loop controller to navigate in 2D environments.

Secondly, I propose a new …

Using Machine Learning Methods To Predict The Movement Trajectories Of The Louisiana Black Bear, Daniel Clark, David Shaw, Armando Vela, Shane Weinstock, John Santerre, Joseph D. Clark

SMU Data Science Review

In 1992, the Louisiana black bear (Ursus americanus luteolus) was placed on the U.S. Endangered Species List. This was due to bear populations in Louisiana being small and isolated enough where their populations couldn’t intersect with other populations to grow. Interchange of individuals between subpopulations of bears in Louisiana is critical to maintain genetic diversity and avoid inbreeding effects. Utilizing GPS (Global Positioning System) data gathered from 31 radio-collared bears from 2010 through 2012, this research will investigate how bears traverse the landscape, which has implications for gene exchange. This paper will leverage machine learning tools to improve upon existing …

Robust Optimization With Recourse In Portfolio Management: Theory And Applications To Stocks And Projects, Hedieh Ashrafi, Aurelie Thiele

Operations Research and Engineering Management Theses and Dissertations

Many real-world decision problems in engineering and management have uncertain parameters. Robust optimization methodology takes into account the uncertainty in parameters of the model in the decision-making framework. In robust optimization methodology, we assume we do not know the probability distribution of parameters, and we have partial information about parameters. Portfolio management is one of those famous applications that have an uncertain environment. So, for this application, robust methodology would be a good choice. This dissertation contains three main works as the following:\\ In the first work, we provided the combination of European options and a robust optimization model to …

Heuristics For Capacity Allocation And Queue Assignment In Congested Service Systems With Stochastic Customer Demand And Immobile Servers, Adam Colley

Operations Research and Engineering Management

We propose easy-to-implement heuristics for a problem referred to in the literature as the facility location problem with immobile servers, stochastic demand, and congestion, or the service system design problem. The problem is typically posed as one of allocating capacity to a set of M/M/1 queues to which customers with stochastic demand are assigned with the objective of minimizing a cost function composed of a fixed capacity-acquisition cost, a variable customer-assignment cost, and an expected-waiting-time cost. The expected-waiting-time cost results in a non-linear term in the objective function of the standard binary programming formulation of the problem. Thus, the solution …

Damage Evolution And High-Rate Response Of High-Strength Concrete Under Triaxial Loading, Brett Williams

Mechanical Engineering Research Theses and Dissertations

The research presented in this study focuses on understanding fundamental mechanisms that drive material response under dynamic loading conditions. The objectives of the research were to: (1) to understand damage initiation and propagation in the bulk geomaterial under a variety of loading conditions and (2) to systematically investigate the strain rate effects on the triaxial compressive response of cementitious materials through the development of an innovative, first of its kind large-diameter (50 mm) triaxial Kolsky bar system.

The triaxial compressive response of high-strength concrete is needed to understand pressure-dependent material behavior, which is important for modeling extreme loading events. However, …

Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen

Civil and Environmental Engineering Theses and Dissertations

Heavy metals in the environment add to the global burden of pollution, negatively impacting public health and ecosystem resilience. This study included projects regarding uranium (U), lead (Pb), and rare earth elements (REE) in natural samples, due to their known toxicity, ubiquity, and relevance in context to recent pollution trends. The first project focused on testing the potential of using a hydroxyapatite product as a remediation solution for U-contaminated groundwater and soil at an EPA Superfund site. The results showed that the U was sequestered in a highly crystalline mineral form within the solids, guiding the EPA to specify the …

Three-Dimensional (3d) Memory I/O Interface Design Using Quad-Band Interconnect (Qbi) And Eight-Level Pulse Amplitude Modulation (8-Pam), Xiaoyan Wang

Electrical Engineering Theses and Dissertations

The demand for high bandwidth, low latency, reconfigurable, and small form factor memory I/O interface design has significantly increased with the development of data-intensive applications, such as artificial neural networks and high-performance computing. However, the current memory I/O interface technologies have critical limitations, such as limited bandwidth, limited pin count, long latency, non-reconfigurable data access, and large form factor. Therefore, a novel memory I/O interface design is needed to overcome these limitations.

This dissertation presents two novel memory I/O interface designs using 3D integration, QBI, and 8-PAM technologies to improve bandwidth, latency, reconfigurability, and form factor for future mobile devices. …

Price Optimization For Revenue Maximization At Scale, Nikhil Gupta, Massimiliano Moro, Kailey A. Ayala, Bivin Sadler

SMU Data Science Review

This study presents a novel approach to price optimization in order to maximize revenue for the distribution market of non-perishable products. Data analysis techniques such as association mining, statistical modeling, machine learning, and an automated machine learning platform are used to forecast the demand for products considering the impact of pricing. The techniques used allow for accurate modeling of the customer’s buying patterns including cross effects such as cannibalization and the halo effect. This study uses data from 2013 to 2019 for Super Premium Whiskey from a large distributor of alcoholic beverages. The expected demand and the ideal pricing strategy …