Engineering Commons^™

Design, Assessment, And Comparison Of Antagonistic, Cable-Driven, Variable Stiffness Actuators, Ryan P. Moore

Master's Theses (2009 -)

This thesis presents the designs and test results for two antagonistic, cable-driven, variable stiffness actuator designs. Each of these variable stiffness actuators is compact, has a large range of controllable stiffness, and limits the inertia at the robotic link it is controlling. Each design consists of a cable running through a set of three pulleys. Tension on the cable displaces a linear spring, which moves along a path designed to achieve quadratic spring behavior. One design uses a variable radius path to achieve the nonlinear elastic behavior while the other uses a fixed radius (lever) path.A quasi-static model of …

Multiscale Analysis Of Soil-Strap Interactions In Mechanically Stabilized Earth Retaining Walls, Max Willingham

Master's Theses (2009 -)

A numerical pullout test was built using the discrete element method (DEM) to model and capture the pullout response of steel reinforcements and soil in mechanically stabilized earth (MSE) walls. Through numerical modeling, microscale phenomena showing aggregate behavior in response to the reinforcement can be used to gain insight into the macroscale structure. The general setup of the simulation is a steel specimen encased in a rectangular apparatus filled with particles. A normal pressure is applied to the top layer of particles while the strap is slowly removed from the box until it reaches a prescribed displacement.The simulation was …

Energy Storage Systems For Traction And Renewable Energy Applications, Hamad Abdullah Aldawsari

Master's Theses (2009 -)

Energy storage systems are the set of technologies used to store various forms of energy, and by necessity, can be discharged. Energy storage technologies have a wide range of characteristics and specifications. Like any other technology, each type of energy storage has its pros and cons. Depending on the application, it is crucial to perform a tradeoff study between the various energy storage options to choose the optimal solution based on the key performance objectives and various aspects of those technologies. The purpose of this thesis is to present a thorough literature review of the various energy storage options highlighting …

Monitoring The Performance Of Green Infrastructure: Pervious Pavement And Bioretention, Elizabeth Marie Regier

Master's Theses (2009 -)

Milwaukee, like many other aging cities, struggles with combined sewer overflows, basement backups, and urban stream syndrome. It is increasingly looking to green stormwater infrastructure as a way to alleviate stormwater concerns by treating, retaining, and slowly releasing stormwater near the locations where it falls. However, green stormwater infrastructure varies in its performance, and few studies have been performed in Southeast Wisconsin. Therefore, two bioswales and a pervious pavement installation were monitored for water quantity, total nitrogen, total phosphorus, and total suspended solids. The bioswales were also monitored for dissolved phosphorus. The north bioswale reduced total phosphorus concentrations by a …

Contributions To The Theory And Application Of Multiple Model Estimation, Alia R. Strandt

Dissertations (1934 -)

Multiple model estimation is a versatile technique that has been applied in a large variety of adaptive estimation problems. In this technique, several estimators, each designed around a possible model of the system, are used in parallel, and the estimator that most closely models the true system is determined using Bayes’ Rule. In this dissertation, convergence properties of the multiple model estimation algorithm are investigated, including a proof of convergence and factors that influence convergence time. In addition, the multiple model estimation algorithm is applied in two parameter estimation problems.The first half of the dissertation focuses on properties of the …

Reaching Performance In Heathy Individuals And Stroke Survivors Improves After Practice With Vibrotactile State Feedback, Valay A. Shah

Dissertations (1934 -)

Stroke causes deficits of cognition, motor, and/or somatosensory functions. These deficits degrade the capability to perform activities of daily living (ADLs). Many research investigations have focused on mitigating the motor deficits of stroke through motor rehabilitation. However, somatosensory deficits are common and may contribute importantly to impairments in the control of functional arm movement. This dissertation advances the goal of promoting functional motor recovery after stroke by investigating the use of a vibrotactile feedback (VTF) body-machine interface (BMI). The VTF BMI is intended to improve control of the contralesional arm of stroke survivors by delivering supplemental limb-state feedback to the …

Patient-Specific Modeling Of Altered Coronary Artery Hemodynamics To Predict Morbidity In Patients With Anomalous Origin Of A Coronary Artery, Atefeh Razavi

Dissertations (1934 -)

Anomalous aortic origin of a coronary artery (AAOCA) is a condition where a coronary artery arises from the opposite aortic sinus, often with acute angle of origin (AO). AAOCA is associated with ischemia.1 This is especially concerning when the anomalous coronary artery takes an intramural course within the aortic wall, creating the potential for distortion or compression. Unroofing surgery replaces a restrictive ostium and intramural segment with a large ostium from the appropriate sinus and aims to create a less acute AO. Although these anatomical features may alter coronary artery blood flow patterns, hemodynamic indices such as time averaged wall …

Eeg Characterization Of Sensorimotor Networks: Implications In Stroke, Dylan Blake Snyder

Dissertations (1934 -)

The purpose of this dissertation was to use electroencephalography (EEG) to characterize sensorimotor networks and examine the effects of stroke on sensorimotor networks. Sensorimotor networks play an essential role in completion of everyday tasks, and when damaged, as in stroke survivors, the successful completion of seemingly simple motor tasks becomes fantasy. When sensorimotor networks are impaired as a result of stroke, varying degrees of sensorimotor deficits emerge, most often including loss of sensation and difficulty generating upper extremity movements. Although sensory therapies, such as the application of tendon vibration, have been shown to reduce the sensorimotor deficits after stroke, the …

Characterization Of Neuroimage Coupling Between Eeg And Fmri Using Within-Subject Joint Independent Component Analysis, Nicholas Heugel

Dissertations (1934 -)

The purpose of this dissertation was to apply joint independent component analysis (jICA) to electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to characterize the neuroimage coupling between the two modalities. EEG and fMRI are complimentary imaging techniques which have been used in conjunction to investigate neural activity. Understanding how these two imaging modalities relate to each other not only enables better multimodal analysis, but also has clinical implications as well. In particular, Alzheimer’s, Parkinson’s, hypertension, and ischemic stroke are all known to impact the cerebral blood flow, and by extension alter the relationship between EEG and fMRI. By characterizing …

Probabilistic Framework For Balancing Smart Grid's Performance Enhancement And Resilience To Cyber Threat, Rezoan Ahmed Shuvro

Dissertations (1934 -)

Critical infrastructures such as smart grids rely heavily on the seamless interaction between the grid subcomponents, i.e., the communication networks which transfers information from and to the grid, and the human operators/AI agents for taking necessary control actions. Smart grids are prone to cascading failures, which trigger from a few initial the tripping of a few transmission lines or generators, creating a ripple effect in the entire network, which may, in turn, lead to a total blackout. Having additional information through the communication network increases the probability of taking better control actions (e.g., effective load shedding and other protection mechanisms), …

Indirect Structural Connectivity As A Biomarker For Stroke Motor Recovery, Miguel Renato Sotelo Munoz

Dissertations (1934 -)

In this dissertation project, we demonstrated that diffusion magnetic resonance imaging and measures of indirect structural brain connectivity are sensitive to changes in fiber integrity and connectivity to remote regions in the brain after stroke. Our results revealed new insights into the effects local lesions have on global connectivity—in particular, the cerebellum—and how these changes in connectivity and integrity relate to motor impairment. We tested this methodology on two stroke groups—subacute and chronic—and were able to show that indirect connectivity is sensitive to differences in connectivity during stroke recovery. Our work can inform clinical methods for rehabilitating motor function in …

Detailed Modeling Of A Small-Scale Turbulent Pool Fire, Bifen Wu, Somesh Roy, Xinyu Zhao

Mechanical Engineering Faculty Research and Publications

Turbulent pool fires have been studied as a canonical configuration in fire science with wide interest. A numerical study of a small-scale turbulent heptane pool fire is conducted in the present study to understand the interactions and coupling among turbulence, chemistry, soot, and radiation in pool fires. A Monte Carlo ray tracing based radiation solver, with line-by-line spectral models for five gaseous species and soot, is coupled with a fireFOAM-based reacting flow solver to describe the dynamics of the target fire. A 33-species skeletal mechanism is employed to describe the finite-rate chemistry. A two-equation soot model with C₂H …

An Integrated Computational Materials Engineering-Anchored Closed-Loop Method For Design Of Aluminum Alloys For Additive Manufacturing, Saket Thapliyal, Mageshwari Komarasamy, Shivakant Shukla, Le Zhou, Holden Hyer, Sharon Park, Yongho Sohn, Rajiv S. Mishra

Mechanical Engineering Faculty Research and Publications

A closed-loop approach based on integrated computational material engineering was used to design, fabricate and characterize an Al–1.5Cu–0.8Sc–0.4Zr (wt%) alloy for laser powder bed fusion additive manufacturing (AM). Finalization of composition and prediction of solidification behavior and mechanical properties were done using calculation of phase diagrams (CALPHAD) and analytical tools. The microstructure of the printed alloy in as-built condition consisted of crack-free regions with fine-equiaxed grains which was consistent with CALPHAD results. Yield strength (YS) of ~349 ± 8 MPa was also in more than 90% agreement with predicted YS. The findings demonstrate an efficient methodology for application-based alloy design …

Low-Cost Interior Permanent Magnet Machine With Multiple Magnet Types, Qingqing Ma, Ayman M. El-Refaie, Bruno Lequesne

Electrical and Computer Engineering Faculty Research and Publications

This article is a contribution to answer the following question: Is it possible to design a permanent magnet machine with the performance expected from rare-earth magnets but at a lower cost? Performance being understood as torque, size, efficiency, demagnetization, and temperature rise together. The question is addressed with a systematic exploration of different interior permanent magnet machine topologies mixing rare-earth and ferrite permanent magnets. The study starts from a production baseline, the Prius 2010 traction motor, with interior magnets placed in a single V pattern. It investigates various rotor designs, most specifically, single V and double V patterns as well …

Energy-Efficient Uav-Assisted Mobile Edge Computing: Resource Allocation And Trajectory Optimization, Mushu Li, Nan Cheng, Jie Gao, Yinlu Wang, Lian Zhao, Xuemin Shen

Electrical and Computer Engineering Faculty Research and Publications

In this paper, we study unmanned aerial vehicle (UAV) assisted mobile edge computing (MEC) with the objective to optimize computation offloading with minimum UAV energy consumption. In the considered scenario, a UAV plays the role of an aerial cloudlet to collect and process the computation tasks offloaded by ground users. Given the service requirements of users, we aim to maximize UAV energy efficiency by jointly optimizing the UAV trajectory, the user transmit power, and computation load allocation. The resulting optimization problem corresponds to nonconvex fractional programming, and the Dinkelbach algorithm and the successive convex approximation (SCA) technique are adopted to …

Integrated Resource Management For Terrestrial-Satellite Systems, Shu Fu, Jie Gao, Lian Zhao

Electrical and Computer Engineering Faculty Research and Publications

As data traffic in terrestrial-satellite systems surges, the integration of power allocation for caching, computing, and communication (3C) has attracted much research attention. However, previous works on 3C power allocation in terrestrial-satellite systems mostly focus on maximizing the overall system throughput. In this paper, we aim to guarantee both throughput fairness and data security in terrestrial-satellite systems. Specifically, we first divide the system implementation into three steps, i.e., data accumulation, blockchain computing, and wireless transmission. Then, we model and analyze the delay and power consumption in each step by proposing several theorems and lemmas regarding 3C power allocation. Based on …

Partially-Coupled D–Q–0 Components Of Magnetically-Isolated Fscw Ipm Machines With Open-End-Winding Drives, Fan Wu, Hao Ge, Ayman M. El-Refaie, Mohammad Farshadnia, Alireza Pouramin, Rukmi Dutta

Electrical and Computer Engineering Faculty Research and Publications

Fractional-slot concentrated winding interior permanent magnet (FSCW-IPM) machines have been designed with very low winding mutual inductance for magnetic isolation features required for improving their fault-tolerant capabilities. These magnetically-isolated FSCW-IPM machines no longer adhere to the preconditions required for a conventional abc-to-dq0 transformation. As a result, it is found in this article that d-, q-axes could couple with 0-axis in magnetically-isolated FSCW-IPM machines. Considering the second-order reluctance component, this phenomenon leads to third-harmonic injection in phase voltages during normal operation, which can be cancelled out in terms of line-to-line voltage for Y-connected three-phase system. However, for open-end-winding machine drives without …

Toward Additively Manufactured Electrical Machines: Opportunities And Challenges, Fan Wu, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

With the growing interest in electrification and as hybrid and pure electric powertrains are adopted in more applications, electrical machine design is facing challenges in terms of meeting very demanding performance metrics, for example, high specific power, and harsh environments. This provides clear motivation to explore the impact of advanced materials and manufacturing on the performance of electrical machines. This article provides an overview of additive manufacturing (AM) approaches that can be used for constructing electrical machines, with a specific focus on additively manufactured iron core, winding, insulation, and permanent magnet, as well as cooling systems. Since there has only …

Sensitivity Calculations Of High-Speed Optical Receivers Based On Electron-Apds, Vladimir Shulyak, Majeed M. Hayat, Jo Shien Ng

Electrical and Computer Engineering Faculty Research and Publications

Sensitivity of high-speed optical receivers is heavily influenced by the performance of the optical detectors used in the receivers, the data rate, and the target bit-error-rate (BER). A simulation model for sensitivity of optical receivers based on electron-avalanche photodiodes (e-APDs) is presented. It allows for the optimization of avalanche width and operating voltage to achieve the optimum receiver sensitivity for given bit rate and target BER. The effects modelled include inter-symbol interference (ISI), various dark current components (tunnelling, diffusion, and generation), current impulse duration, avalanche gain, and amplifier's noise. The model was demonstrated through simulations of Indium Arsenide (InAs) e-APDs. …

Removal Of Estrogenic Compounds From Water Via Energy Efficient Sequential Electrocoagulation-Electrooxidation, Emily K. Maher, Kassidy N. O'Malley, Michael Dollhopf, Brooke K. Mayer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

The purpose of this study was to investigate energy reduction using electrocoagulation (EC) followed by electrooxidation (EO) targeting initial removal of dissolved organic carbon (DOC) during EC and subsequent removal of estrogenic compounds in EO. EC offers benefits over conventional coagulation such as in situ generation of coagulant but is not practical for removing estrogenic compounds. Advanced oxidation processes, including EO, can effectively remove micropollutants such as estrogenic compounds but are hindered by the presence of bulk organic matter. This study investigated four estrogenic compounds from the U.S. EPA's Contaminant Candidate List: estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol …

Iron-Electrocoagulation As A Disinfection Byproduct Control Strategy For Drinking Water Treatment, Donald R. Ryan, Patrick J. Mcnamara, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Disinfection byproducts (DBPs) result from reactions between oxidizing disinfectants, e.g., free chlorine, and DBP precursors such as natural organic matter (NOM). Electrocoagulation (EC) has potential as an effective DBP precursor removal strategy for decentralized water treatment and small drinking water utilities as it features similar removal trends compared to conventional coagulation, without alkalinity consumption, while also generating coagulant in situ by anodic dissolution of iron electrodes. However, studies assessing DBP formation in drinking water following EC treatment are lacking. This research evaluated EC as a DBP precursor removal strategy by quantifying reductions in total trihalomethane (TTHM) formation potential as …

A Quasi-Monte Carlo Solver For Thermal Radiation In Participating Media, Joseph Farmer, Somesh Roy

Mechanical Engineering Faculty Research and Publications

The Monte Carlo (MC) method is the most accurate method for resolving radiative heat transfer in participating media. However, it is also computationally prohibitive in large-scale simulations. To alleviate this, this study proposes a quasi-Monte Carlo (QMC) method for thermal radiation in participating media with a focus on combustion-related problems. The QMC method employs low-discrepancy sequences (LDS) in place of the traditional random numbers. Three different low-discrepancy sequences – Sobol, Halton, and Niederreiter – were examined as part of this work. The developed QMC method was first validated against analytical solutions of radiative heat transfer in several one-dimensional configurations. Then …

Benzalkonium Chloride Alters Phenotypic And Genotypic Antibiotic Resistance Profiles In A Source Water Used For Drinking Water Treatment, Katherine R. Harrison, Anthony D. Kappell, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Antibiotic resistance is a major public health concern. Triclosan is an antimicrobial compound with direct links to antibiotic resistance that was widely used in soaps in the U.S. until its ban by the U.S. Food and Drug Administration. Benzalkonium chloride (BAC), a quaternary ammonium compound, has widely replaced triclosan in soaps marketed as an antibacterial. BAC has been detected in surface waters and its presence will likely increase following increased use in soap products. The objective of this study was to determine the effect of BAC on relative abundance of antibiotic resistance in a bacterial community from a surface water …

Behavior Of Circular Ice-Filled Self-Luminous Frp Tubular Stub Columns Under Axial Compression, Yanlei Wang, Guipeng Chen, Baolin Wan, Gaochuang Cai, Yiwen Zhang

Civil and Environmental Engineering Faculty Research and Publications

This paper proposes an innovative ice-filled self-luminous fiber-reinforced polymer (FRP) tubular (IFSFT) column for temporary structures in cold regions. The proposed column possesses a good combination of the advantages of FRP tube and natural ice, as well as provides itself with aesthetic features or other service functions due to the self-luminous feature of the outer FRP tube in darkness. This paper presents an experimental study on tensile and luminance properties of FRP laminates modified with self-luminous powders, and axial compressive behavior of circular IFSFT stub columns and ice-filled FRP tubular (IFFT) stub columns. Experimental results indicate that the addition of …

Ai-Assisted Network-Slicing Based Next-Generation Wireless Networks, Xuemin Shen, Jie Gao, Wen Wu, Kangjia Lyu, Mushu Li, Weihua Zhuang, Xu Li, Jaya Rao

Electrical and Computer Engineering Faculty Research and Publications

The integration of communications with different scales, diverse radio access technologies, and various network resources renders next-generation wireless networks (NGWNs) highly heterogeneous and dynamic. Emerging use cases and applications, such as machine to machine communications, autonomous driving, and factory automation, have stringent requirements in terms of reliability, latency, throughput, and so on. Such requirements pose new challenges to architecture design, network management, and resource orchestration in NGWNs. Starting from illustrating these challenges, this paper aims at providing a good understanding of the overall architecture of NGWNs and three specific research problems under this architecture. First, we introduce a network-slicing based …

Structural And Environmental Impact Of New-Generation Wide-Base Tires In New Brunswick, Canada, Izak M. Said, Jaime Hernandez, Seunggu Kang, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

The loading and environmental impacts of new-generation wide-base tires (NG-WBT) and dual tire assemblies (DTA) on typical asphalt concrete (AC) pavement sections of New Brunswick, Canada were evaluated using finite element method (FEM) analysis and life-cycle assessment. The impact of steering wheel was not considered in this study. The analysis considered realistic material models and loading conditions (i.e. AC viscoelastic characteristics and measured three-dimensional nonuniform tire–pavement contact loads). Predicted critical pavement responses were used in transfer functions to determine potential pavement damage. The NG-WBT loading resulted in greater critical pavement responses compared to that of DTA, especially near the surface …

Effect Of O2 Concentration In Ambient Mixture And Multiphase Radiation On Pollutant Formation In Ecn Spray-A, Khaled Mosharraf Mosharraf Mukut, Somesh Roy

Mechanical Engineering Faculty Research and Publications

The present study investigates the formation and evolution of soot and NO_X in a high-pressure constant-volume combustion chamber. This work focuses on the effect of multiphase thermal radiation and O₂ dilution in ambient/exhaust gases, some- times also referred to as exhaust gas recirculation(EGR), qualitatively and quantitatively. The spray-A case (n-dodecane as fuel) from Engine Combustion Network (ECN) is used as the target condition. Two different soot modeling approaches have been considered: a semi-empirical two-equation model and a detailed method of moments with interpolative closure (MOMIC) model. A multiphase photon Monte Carlo (PMC) solver with line-by-line (LBL) spectral data …

Cone Identification In Choroideremia: Repeatability, Reliability, And Automation Through Use Of A Convolutional Neural Network, Jessica I.W. Morgan, Min Chen, Andrew M. Huang, Yu You Jiang, Robert F. Cooper

Biomedical Engineering Faculty Research and Publications

Purpose: Adaptive optics imaging has enabled the visualization of photoreceptors both in health and disease. However, there remains a need for automated accurate cone photoreceptor identification in images of disease. Here, we apply an open-source convolutional neural network (CNN) to automatically identify cones in images of choroideremia (CHM). We further compare the results to the repeatability and reliability of manual cone identifications in CHM.

Methods: We used split-detection adaptive optics scanning laser ophthalmoscopy to image the inner segment cone mosaic of 17 patients with CHM. Cones were manually identified twice by one experienced grader and once by two …

Liana Abundance And Diversity Increase With Rainfall Seasonality Along A Precipitation Gradient In Panama, Anthony J. Parolari, Kassandra Paul, Aaron H. Griffing, Richard Condit, Ronaldo Perez, Salomón Aguilar, Stefan A. Schnitzer

Civil and Environmental Engineering Faculty Research and Publications

In tropical regions, rainfall gradients often explain the abundance and distribution of plant species. For example, many tree and liana species adapted to seasonal drought are more abundant and diverse in seasonally-dry forests, characterized by long periods of seasonal water deficit. Mean annual precipitation (MAP) is commonly used to explain plant distributions across climate gradients. However, the relationship between MAP and plant distribution is often weak, raising the question of whether other seasonal precipitation patterns better explain plant distributions in seasonally-dry forests. In this study, we examine the relationship between liana abundance and multiple metrics of seasonal and annual rainfall …

A Size‐Modified Poisson–Boltzmann Ion Channel Model In A Solvent Of Multiple Ionic Species: Application To Voltage‐Dependent Anion Channel, Dexuan Xie, Said H. Audi, Ranjan K. Dash

Biomedical Engineering Faculty Research and Publications

We present a new size‐modified Poisson–Boltzmann ion channel (SMPBIC) model and use it to calculate the electrostatic potential, ionic concentrations, and electrostatic solvation free energy for a voltage‐dependent anion channel (VDAC) on a biological membrane in a solution mixture of multiple ionic species. In particular, the new SMPBIC model adopts a membrane surface charge density and a natural Neumann boundary condition to reflect the charge effect of the membrane on the electrostatics of VDAC. To avoid the singularity difficulties caused by the atomic charges of VDAC, the new SMPBIC model is split into three submodels such that the solution of …