Digital Commons Network^™

Localized Multivariate Statistical Assessment Of United States Construction Labor Shortages, Ahmed Shiha, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Craft labor shortage is a persistent challenge facing the construction industry across various markets. The historically low geographic mobility of construction labor exacerbates and localizes labor shortages. Several research efforts relied on subjective evaluations to quantify the existence of labor shortages on a national level. As such, there is a lack of empirical quantification of labor shortages at different geospatial levels. This paper fills this knowledge gap. To this end, the authors adopted a methodology that encompassed: (1) conducting a literature review to identify and collect national-level and subnational indicators that explain the changes in labor supply and demand; (2) …

Coupling Effect Of Abrasion And Erosion On Ultrahigh-Performance Seawater-Sea Sand Concrete, Dawei Ding, Wei Zhang, Lanqin Wang, Hongyan Ma, Biqin Dong, Song Han, Hongjian Xu, Dongshuai Hou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Preparing ultrahigh-performance seawater-sea sand concrete (UHPSSC) to mitigate the scarcity of freshwater and river sand resources has generated considerable recent research interest. However, the deterioration mechanisms of UHPSSC under the effect of abrasion and erosion remain unstudied. In this paper, the underwater steel ball method was conducted to evaluate the impact of seawater, sea sand, steel fiber, and seawater abrasion on the abrasion resistance of UHPSSC. Then the stress erosion models of calcium-silicate-hydrate (C-S-H) were constructed to investigate the degradation mechanisms of UHPSSC under the effect of external stress and seawater erosion. The results show that the application of seawater …

Influence Of Mixing Duration And Absorption Characteristics Of Superabsorbent Polymers On The Fresh And Hardened Properties Of High-Performance Concrete, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the combined influence of superabsorbent polymers (SAPs) with distinct absorption kinetics and extended mixing sequences on the rheological, mechanical, and transport properties of high-performance concrete (HPC). Two SAPs—an ionic acrylamide-co-acrylic acid copolymer (SAP-P) and a non-ionic acrylamide polymer (SAP-B)—were incorporated at an internal curing level of 100%. The impact of extended mixing times (3, 5, and 7 min) following SAP addition was systematically evaluated. Results showed that longer mixing durations led to increased superplasticizer demand and higher plastic viscosity due to continued water absorption by SAPs. However, yield stress remained relatively stable owing to the dispersing effect …

Microstructural Investigation Of Graphene Reinforced Nickel Aluminum Bronze Prepared Via Laser Powder Bed Fusion, Wen Qian, Maxwyll Mcconnell, Jazmin Ley, Luke Schwaninger, Xin Chen, Bai Cui, Joseph A. Turner

Mechanical Engineering Faculty Publications

Nickel aluminum bronze (NAB) powders coated with reduced graphene oxide (RGO) were successfully fabricated using additive manufacturing (AM) via laser powder bed fusion. The resulting samples were characterized using a suite of complementary techniques, including x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectroscopy, nanoindentation, x-ray computed tomography, and electron backscatter diffraction. These methods were employed to reveal the micro- and nanoscale features within the fine dendritic microstructure. The as-fabricated microstructures were observed to deviate significantly from typical as-cast configurations. In the AM RGO-coated NAB specimens, the formation of the κ_I phase was notably suppressed and is attributed to the …

Enhancing Microgrid Protection Through Adaptive Decentralized Relay Coordination: A Solution To Blinding And Sympathetic Tripping, Sujatha Balasubramanian, J. Preetha Roselyn, Prabha Sundaravadivel

Electrical Engineering Faculty Publications and Presentations

Integrating Distributed Energy Resources into microgrids modifies the network’s system parameters and causes it to exhibit behaviour, particularly during fault conditions. This is due to the greater variations in current direction and magnitude. When a microgrid runs in autonomous mode, Distributed Generators result in a reduced short circuit current compared to a system working in grid-connected mode. Microgrid protection issues, namely, blinding of protection, sympathetic tripping, and bidirectional power flow, occur in the power network under such circumstances. The impact of microgrid protection issues and changes in fault current leads to variations of overcurrent relay settings, their operating time and …

Heat-Pipe-Based Thermal Management System Design For A 250-Kw Gan-Based Integrated Modular Motor Drive, Seyed Iman Hosseini Sabzevari, Salar Koushan, Armin Ebrahimian, Towhid Islam Chowdhury, Nathan Weise, Ayman El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

Integrated modular motor drive (IMMD) is an effective approach for realizing high-efficiency, high-power-density, and fault-tolerant electric machines. However, designing an efficient thermal management system (TMS) for the motor drive becomes a challenge, particularly due to space constraints. This article presents the design of a TMS based on 3-mm heat pipes for a 250-kW IMMD intended for aviation applications. The power electronics module is simulated using PLECS software where an electrothermal analysis is conducted. A simplified thermal resistance model of the system is developed to estimate the die junction temperature of gallium nitride (GaN) semiconductors. The performance of the proposed TMS …

Modification Of Tini Alloy By Fast Pulse Laser Heat Treatment, Yitao Chen, Mohammad Masud Parvez, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this study, the effects of local heat treatment with fast pulse laser on thin TiNi shape memory alloy strip materials were investigated. Various materials characterization methods including optical microscope, scanning electron microscope, atomic force microscope, X-ray diffraction, differential scanning calorimetry, and Vickers hardness were used to identify the differences of microstructure, mechanical properties, and functional properties between regions inside and outside the laser-scanned region. The tensile test was also conducted for both the non-laser-scanned specimen and the laser-scanned specimen. The area covered by laser scanning shows great differences by possessing a more homogeneous austenite phase without shear bands and …

Digital Twins, Ai, And Cybersecurity In Additive Manufacturing: A Comprehensive Review Of Current Trends And Challenges, Md Sazol Ahmmed, Laraib Khan, Muhammad Arif Mahmood, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The development of Industry 4.0 has accelerated the adoption of sophisticated technologies, including Digital Twins (DTs), Artificial Intelligence (AI), and cybersecurity, within Additive Manufacturing (AM). Enabling real-time monitoring, process optimization, predictive maintenance, and secure data management can redefine conventional manufacturing paradigms. Although their individual importance is increasing, a consistent understanding of how these technologies interact and collectively improve AM procedures is lacking. Focusing on the integration of digital twins (DTs), modular AI, and cybersecurity in AM, this review presents a comprehensive analysis of over 137 research publications from Scopus, Web of Science, Google Scholar, and ResearchGate. The publications are categorized …

Building A Sustainable Home On The Central Coast: An Owner’S Perspective, Austin Chase Anderson

Construction Management

As awareness and technology increase, sustainability as a focus in home construction is also increasing. This case study based research project seeks to understand the process of building a home on California’s Central Coast with sustainability in mind. An interview was conducted with an owner who built their home in Templeton in 2019. The interview was in a semi-structured format which included specific qualitative questions but mostly focused on an open-ended discussion which allowed the owner to share their own experience. The key challenges learned from this interview were that the owner believed price to be the main factor that …

From Waste To Solution: Modeling And Characterization Of Grape Seed Bio-Waste For Phosphate Removal From Wastewater, Abeer Al-Bsoul, Zakaria Al-Qodah, Muhammad Tawalbeh, Khalid Bani-Melhem, Khalideh Al Bkoor Alrawashdeh, Mohammad Hailat, Ahmed A. Al-Taani, Eid Gul

All Works

In this study, particles of ground grape seeds were utilized to adsorb phosphate ions from a prepared solution, aiming to reduce phosphate concentration. Through a series of adsorption experiments, the effects of the adsorbent concentration, initial phosphate ion concentration, temperature, and pH on the phosphate ion uptake were studied. The removal efficiency of the phosphate ion decreased from 77 to 61% as a 25 to 45 °C increment in temperature was observed, which indicated the exothermicity in the adsorption process. The phosphate ion movement onto the adsorbent surface that exhibited the highest uptake value favored a neutral reaction environment with …

Validation Of A Methodology For Predicting Yield Acceleration Of Rock Blocks, Madison Haydn-Myer

Graduate Theses & Non-Theses

Rock slope stability is a critical concern in seismically active regions, where earthquakes can trigger sudden and hazardous failures. Predicting these failures is challenging due to the complex interactions between seismic loading and geological characteristics. This study proposes a simplified analytical model to predict yield acceleration based on the forces acting upon a block just before sliding initiates. A key parameter in this equation is the friction acting on the bottom surface of the block. As rock blocks are commonly formed by the intersection of sets of subparallel fractures known as joints, and the roughness and other features of those …

Axicons For Improved Resolution And Depth Of Focus In Adaptive Optics Scanning Light Ophthalmoscopy, Ruth E. Woehlke, Robert F. Cooper

Biomedical Engineering Faculty Research and Publications

Adaptive optics scanning light ophthalmoscopes are instrumental for studying the eye, yet they use truncated Gaussian illumination and are limited by diffraction, restricting resolution and depth of focus (DOF). Non-diffractive Bessel beams have emerged as an alternative. Here, we use two axicons configured as: (1) an extended DOF beam for resolving multiple retinal layers; and (2) an annular beam for increasing lateral resolution. We compare both approaches to truncated Gaussian illumination using a variety of metrics. Using Configuration 1, we successfully observed multiple retinal layers simultaneously. Using Configuration 2, we observed enhanced lateral resolution but decreased signal-to-noise ratio.

Predictors Of Permanent And Temporary Motor Deficits In Patients Undergoing Glioma Resection: A Systematic Review And Meta-Analysis, Brian J. Conway, Stephanie A. Armstrong, Nada Botros, Sergey Tarima, Max O. Krucoff

Biomedical Engineering Faculty Research and Publications

Objective

To identify predictors of permanent and temporary motor deficits in patients undergoing glioma resection.

Methods

A literature search accessed the databases Ovid Medline, Scopus, Web of Science, Cumulative Index to Nursing and Allied Health Literature/EBSCO, PsychInfo, Cochrane, and Wiley for studies reporting motor outcomes following surgical resection of glioma. Outcomes were stratified by patient/tumor characteristics, preoperative condition, and intraoperative factors for both permanent and temporary motor deficits. Generalized estimating equations were used to generate odds ratios.

Results

A total of 1332 titles and abstracts were reviewed resulting in the evaluation of 261 full-text articles. Data were extracted from 67 …

Mantle Flow And Crustal Deformation Revealed By Seismic Anisotropy In The Subduction Zone Beneath Myanmar, Enbo Fan, Mingming Jiang, Yinshuang Ai, Stephen S. Gao, Kelly H. Liu, Yumei He, Yiming Bai, Guangbing Hou, Yuan Ling, Chit Thet Mon, Myo Thant, Kyaing Sein

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The oblique convergence of the Indian and Eurasian plates drives significant deformation in the crust and mantle beneath Myanmar. However, the crustal deformation in the Indo-Burman Ranges (IBR) and mantle flow beneath Myanmar and adjacent areas remain unclear due to limited studies. We utilized data from the newly deployed second phase of the China-Myanmar Geophysical Survey of the Myanmar Orogen array to perform shear wave splitting analysis of PKS, SKKS, and SKS (XKS) phases. Our results, together with previous findings, provide new insights into mantle flow and crustal deformation across central Myanmar. In the IBR, we observed a transition from …

3d Printing Of Short Fiber Reinforced Polypropylene: Novel Lattice Architecture And Material Characterization, Mohammad Ghazi Alshneeqat

Theses

This study explores the enhanced compressive behavior of 3D-printed single and double gyroid solid-networks lattices. Where the double gyroids are constructed from two intertwined single gyroid structures. These structures were designed by nTop implicit modeling tool and then fabricated by material extrusion additive manufacturing method at optimized printing parameters, including optimized nozzle temperature and raster angle. The main objective of this study is to reveal the compressive behavior of the novel double gyroid lattice structure and then to tailor its response through variable gyroid heights. Standard polymer tests were performed, considering thermogravimetric analysis, to confirm the thermal stability of the …

Synergistic Enhancement Of Tribological Behavior And Colloidal Stability In Cuo Nanolubricants Via Ligand Tuning, Sherif Elsoudy, Sayed Akl Akl Dr, Sayed Akl A. Akl Dr, Esm Lane, Abas Hadawey, Philip D. Howes

Mechanical Engineering

Nanoparticle-based lubricants, or nanolubricants, can exhibit superior tribological properties compared to unmodified base oils. However, these performance gains are highly dependent on the nanoparticle surface chemistry, particularly in maintaining stable colloidal dispersions. This study explores the influence of oleic acid (OA) and oleylamine (OAm) functionalization on the tribological and colloidal properties of CuO nanoparticles dispersed in an SAE 20W50 base oil. We present a hybrid optimization framework combining Response Surface Methodology (RSM) with Bayesian Optimization (BO) to identify the optimal OA to OAm ratio (OA–OAm) for CuO nanolubricants. Unlike prior studies that employed either RSM alone or trial-and-error approaches, this …

Two Analytic Issues Arising From Models In Probability And Materials Science, Giang Vu Thanh Nguyen

Mathematics & Statistics Theses & Dissertations

This dissertation explores two distinct topics centered on mathematical models in probability theory and materials science. The first part investigates a series of functions derived from an adaptive algorithm designed to address the score-based secretary problem, a classic challenge in probability theory. This problem involves making immediate decisions to select the best candidate from a sequence of interviews. The algorithm aims to maximize the probability of selecting the optimal candidate based on observed scores. We prove two fundamental analytic properties of this sequence of functions as a theoretic support of the algorithm: first, the functions in the sequence each possess …

Multimedia Forensics: Identification And Verification Of Source Camera, Vehicle Speed Estimation, And Deepfakes Detection, Jiajun Jiang

Electrical & Computer Engineering Theses & Dissertations

This dissertation advances multimedia forensics by addressing three critical research areas that enhance the authenticity verification and analysis of digital media. Multimedia forensics, which encompasses techniques for examining images, videos, audio, and text, faces increasing challenges due to sophisticated editing tools and massive data volumes. In the first study, a fast source camera identification and verification method based on PRNU analysis is proposed for video forensic investigations. By integrating camera rolling and I-frame analysis, this approach achieves a processing speed improvement of at least 15 times over conventional frame-by-frame methods while reducing false positives. The second study focuses on vehicular …

Effect Of Moderate Decrease In Contractility On Epithelial Cell-Cell Contacts Under External Stretch, Saika Sharmin

Mechanical & Aerospace Engineering Theses & Dissertations

Epithelial tissues are characterized by extensive cell–cell contacts and often subject to stretch during normal function. Cell-cell contact adhesion strength maintains mechanical continuity from cell to cell. Mechanical forces exerted by cells via actomyosin contractility are known to strengthen cell-cell adhesions to a certain extent. While it is known that a large decrease in contractility causes cell-cell contact rupture due to weakened adhesions, it is unclear how a moderate reduction in contractility affects cell-cell junction stability. Here, we studied how a moderate inhibition of non-muscle myosin II (NMII) affects the integrity of epithelial cell-cell contacts, especially when subject to the …

Systems Statistical Engineering – Hierarchical Fuzzy Constraint Propagation, Hengameh Fakhravar

Engineering Management & Systems Engineering Theses & Dissertations

Driven by the growing need in the 21st century for integrating rigorous statistical analysis into engineering research, there is a movement to develop an integrated statistical engineering science within statistics and quality communities (Hoerl & Snee, 2010; Anderson-Cook et al., 2012). Systems Statistical Engineering research seeks to integrate the Causal Bayesian hierarchical modeling (Pearl, 2009) and cybernetic control theory within Beer’s Viable System Model (1972, 1979, 1985) and the Complex Systems Governance framework (Keating, 2014; Keating & Katina, 2015, 2016) to produce multivariate systemic models for robust dynamic systems mission performance. Cotter & Quigley (2018) set forth the Bayesian systemic …

A Three-Stage Matheuristic For The Blood Stochastic Inventory Routing Problem, Vincent F. Yu, Nabila Salsabila, Aldy Gunawan, Aldy Gunawan, Nurhadi Siswanto

Research Collection School Of Computing and Information Systems

This research introduces a blood distribution system under vendor-managed inventory that considers uncertain supply and demand. We present it as the Blood Stochastic Inventory Routing Problem, formulating it as a two-stage stochastic programming model. To solve this problem, this study proposes a three-stage matheuristic that combines a perturbation heuristic, Adaptive Large Neighborhood Search, and an exact approach. From historical data of Surabaya Blood Center in Indonesia, six sets of new instances are generated under different settings. Computational results show that our proposed three-stage matheuristic outperforms CPLEX and a two-stage matheuristic by gaining optimal or better solutions within a significantly shorter …

Assessing The Robustness Of Test Selection Methods For Deep Neural Networks, Qiang Hu, Yuejun Guo, Xiaofei Xie, Maxime Cordy, Wei Ma, Mike Papadakis, Lei Ma, Yves Le Traon

Research Collection School Of Computing and Information Systems

Regularly testing deep learning-powered systems on newly collected data is critical to ensure their reliability, robustness, and efficacy in real-world applications. This process is demanding due to the significant time and human effort required for labeling new data. While test selection methods alleviate manual labor by labeling and evaluating only a subset of data while meeting testing criteria, we observe that such methods with reported promising results are simply evaluated, e.g., testing on original test data. The question arises: are they always reliable? In this article, we explore when and to what extent test selection methods fail. First, we identify …

Supporting Programmers Answering The Hard-To-Answer Questions Through The Use Of Large Language Models, Haixin Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Programmers often face hard-to-answer questions when working on large-scale projects. Not only during team collaborations, but also during interruptions such as meetings, having to suddenly work on another project, or even just taking a break are major reasons these questions arise, as programmers have to regain the context, knowledge, and mental state to resume the work. Traditional text editors such as GitHub do provide a built-in history system, but they lack historical context behind the editing to answer such questions.

To address this issue, we developed an experimental extension, Code History, on Visual Studio Code (VS Code) in the hope …

Challenges And Artificial Intelligence Solutions For Clinically Optimal Hepatic Venous Vessel Segmentation, Håvard Bjørke Jenssen, Varatharajan Nainamalai, Egidijus Pelanis, Rahul P. Kumar, Andreas Abildgaard, Finn Kristian Kolrud, Bjørn Edwin, Jingfeng Jiang, Joseph Vettukattil, Ole Jakob Elle, Smund Avdem Fretland

Michigan Tech Publications

Background:: Liver vessel identification is crucial for clinical disease assessment and treatment planning, especially concerning local treatment of liver tumors. As artificial intelligence (AI) develops in radiology, opportunities arise to craft models adept at hepatic venous vessel segmentation, opening possibilities for creating patient-specific models of the liver anatomy quickly, despite the diverse features of CT images encountered in clinical settings. Objective: This research evaluates the performance of AI models combined with various pre-processing filters for liver vessel segmentation, emphasizing clinically relevant results. A novel evaluation method was introduced to offer more anatomically accurate assessments, moving beyond traditional metrics like the …

Mechanoregulation Of Osteogenesis And Adipogenesis Of Human Mesenchymal Stem Cells, Justin Caron

Master's Theses

Bone-related diseases (e.g., osteoporosis) are primarily treated with pharmacologic therapies that often exhibit limited efficacy and substantial side effects. Currently, bone marrow derived mesenchymal stem cells (MSCs) have become one of most important cell options in bone regeneration due to readily available sources, strong proliferation abilities, weak immune rejection responses, and strong osteogenic differentiation potential. While identifying the most effective approach to enhance osteogenic differentiation of MSCs for bone regeneration is challenging, understanding the regulatory mechanisms is crucial for improving therapeutic efficacy. Recent research has focused on developing strategies to enhance osteogenesis, which involve biophysical and biochemical stimulation. Mechanical and …

Internet Of Things And Modern Digital Evidence Collection, Muhammad T. Haider

Student Theses

The ever-evolving landscape of technology and its innovations are populating our houses, streets and all kinds of industries. The use of smart devices is booming from most developed nations to underdeveloped countries. The complications which come with the use of the Internet of Things has been an active discussion for the past many years. If we look around in a room of 30 people, we will most likely find double the amount of IoT devices than the people in that room. All of those devices are connected to the Internet, and are communicating with data servers across the world. The …

Valorizing Cement Kiln Dust And Glass Powder: A Binder Study On Sustainable Partial Cement Replacement, Sai Kiran Simhadri

Civil & Environmental Engineering Theses & Dissertations

The production of cement ranks as a major source of global CO₂ emissions because of the high energy requirements needed to create clinker. The construction industry is actively seeking ways to reduce its carbon footprint. Utilizing industrial waste materials to partially replace cement can lower emissions. This research evaluates a ternary binder system which uses Cement Kiln Dust (CKD) and Glass Powder (GP) to replace a portion of Type IL (Portland Limestone) cement. The mixes were made with a fixed water-to-binder ratio of 0.44 and contained 15% GP by mass while the CKD content ranged from 0% to 10%. The …

A Methodology For Model-Based Certification, Jay Albert Silverman

Engineering Management & Systems Engineering Theses & Dissertations

A need for a single source of knowledge for design decisions has led to the development of a new field of systems engineering, model-based systems engineering (MBSE) (Delligati, 2014). System certification is defined as affirming that regulatory requirements for a system have been met (Goodwin & Juzaitis, 2006). System certification is a specific application of system validation. System verification can be defined as ensuring that the system of interest (SOI), as designed, is in accordance with the design inputs/requirements. System validation can be defined as ensuring that the SOI, as designed, meets the defined system needs (Wolfgand, Katz, & Wheatcraft, …

Towards Improving Computational Modeling Of The Lumbar Spine - Impact Of Material Properties And Laminotomy On Spinal Biomechanics, Isaac K. Kumi

Mechanical & Aerospace Engineering Theses & Dissertations

Spinal ligaments play a crucial role in maintaining the mechanical stability of the lumbar spine. These dense, collagenous tissues not only resist excessive motion but also distribute loads between spinal components to protect neural structures. Traditionally, the mechanical response of ligaments has been modeled using linear elastic assumptions, which treat the tissue as having a constant stiffness regardless of loading history. While this simplifies analysis, it fails to capture the time-dependent behaviors, such as creep, stress relaxation, and hysteresis, that are characteristic of biological tissues.

Viscoelastic modeling may provide a more physiologically accurate representation by incorporating both elastic and viscous …

Complex System Governance And Cyber Operations, Willie Gernard Mccallister

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation examines the potential integration of Complex System Governance (CSG) within cybersecurity, emphasizing the development of a reference model for Cybersecurity Infrastructures. Traditional strategies for securing digital environments have struggled to address the intricate and dynamic layers inherent in modern cybersecurity systems. The purpose of this research is to explore the applicability of CSG as a framework to assess cybersecurity infrastructure using a case study research design. The research addresses two key questions: (1) How can the CSG reference model be adapted to explore cybersecurity infrastructure? (2) What results from CSG based exploration of cybersecurity infrastructure through a case …