Engineering Commons^™

Sliding Mode Control In Grid-Tied Inverters: Techniques, Applications, And Future Directions, Taimoor Muzaffar Gondal, Asma Aziz, Daryoush Habibi, Iftekhar Ahmad

Research outputs 2022 to 2026

Sliding mode control (SMC) has emerged as a robust and adaptive strategy for grid-tied inverters. It has unique attributes which make it an appropriate control choice under increasingly complex power systems. However, there are a limited number of review articles which comprehensively explore the true potential of SMC for grid-tied inverter applications. This systematic review has been structured to explore SMC techniques with respect to certain challenges, i.e., stability challenges, unbalanced conditions, low inertia scenarios, and harmonics distortion. The classification of various SMC techniques is presented with respect to their control law and sliding surfaces design. The comparative analysis indicates …

Establishing Sustainability As A Material Property In An Introduction To Materials Science And Engineering Course (Poster), Caitlin Adams

Faculty Publications - Chemical Engineering

No abstract provided.

Sputtered Transport Layers Enabling Ambient-Air Processed Cspbi3 Perovskite Solar Cells, Shamik Datta, Md Abdul Kuddus Sheikh, Md Shazarul Islam, Mohammed Jasim Uddin, Hasina Huq

Electrical and Computer Engineering Faculty Publications

Perovskite solar cells offer promising efficiency compared to traditional technologies. In this study, NiOx and ZnO were employed as charge transport layers using a magnetron sputtering process within a p-i-n architecture (ITO/NiOx/CsPbI3/ZnO/Au). This approach produced uniform, low-defect interfaces and supports low-temperature, scalable fabrication suitable for flexible substrates. Our investigation, using techniques such as X-Ray Diffraction (XRD), UV-Visible spectroscopy, Scanning Electron Microscopy (SEM), and Atomic Force Microscope (AFM), revealed the formation of uniform layers deposited by the magnetron sputtering process. The photoactive CsPbI3 layer was deposited via a spin coating solution process. UV-Visible spectroscopy revealed strong absorbance in the wavelength range …

Design And Evaluation Of A Distributed Ticket Booking System Using Cqrs And Hybrid Consistency Models, Tai Nguyen Vo, Sangwhan Cha

Harrisburg University Other Works

This paper presents the design and evaluation of a Distributed Ticket Booking System (DTBS) built to handle extreme concurrency in high-traffic digital environments. Motivated by real-world failures such as the 2022 Taylor Swift Eras Tour sale—where 14 million simultaneous requests overwhelmed Ticketmaster—the system addresses the fundamental conflict between strong consistency and high availability under massive demand. The proposed solution adopts the Command Query Responsibility Segregation (CQRS) pattern to decouple read and write operations, and applies a hybrid consistency model grounded in the CAP theorem: a CP-oriented booking subsystem with Redis-based distributed locking, and an AP-oriented search subsystem using Elasticsearch for …

Advancing Sensing And Structural Health Monitoring Of Non-Conventional Space Structures, Scott Bender

Doctoral Dissertations and Master's Theses

Future lunar and deep-space missions will require new structural concepts that reduce mass while maintaining reliability. Two technologies that have received significant attention are inflatable habitats and additively manufactured structures; however, challenges remain in their characterization, validation, and long-term monitoring. This dissertation investigates methods to improve the testing and sensing of these non-conventional aerospace structures through the use of advanced photogrammetry and embedded distributed fiber-optic sensors. A color-filtering digital image correlation technique was developed to isolate orthogonal strain directions in woven inflatable structures, providing improved characterization of biaxially loaded softgoods. In addition, methods were developed to embed distributed fiber-optic sensors …

Improving Urban Search And Rescue Team Coordination Through Adaptive Context Awareness, Daniel Reyes Duran

Doctoral Dissertations and Master's Theses

Modern multi-agent Urban Search and Rescue (USAR) operations heavily rely on mobile geospatial Common Operating Pictures (COPs) to maintain team coordination and Situational Awareness (SA). However, the proliferation of high-frequency sensor telemetry at the tactical edge has introduced a data saturation paradox challenge: while information theoretically drives informed decision-making, unmanaged data surges induce increased operator cognitive overload and alert fatigue on mobile End-User Devices (EUDs), while downstream data-broadcasting models inherently strain edge processing and viewport environments.

To resolve these constraints, this dissertation presents a context-aware Value of Information (VoI) data-management framework integrated directly with a custom, event-driven Android Team Awareness …

Artificial Intelligence Based Predictive Simulation And Decision-Support Framework For Full Scale Wastewater Treatment Systems, Muhammad Hassnain, Cameron Veal, Sarada M.W. Lee, Muhammad Rizwan Azhar

Research outputs 2022 to 2026

Full scale wastewater treatment plants (WWTPs) generate extensive sensor and laboratory datasets that remain challenging to translate into real-time operational insight, while increasing hydraulic variability, energy constraints, tightening effluent regulations, and events such as sensor faults, hydraulic shocks, and effluent-quality excursions require predictive decision-support tools beyond conventional mechanistic modelling. This study presents a full-scale, industry-deployed artificial intelligence (AI) framework integrating machine learning (ML), simulation, and operational boundary definition across a nitrogen-removal WWTP in Australia. Up to nine years of high-frequency online instrumentation data (≤419,000 records per target; 5–30 min resolution) and ~3000 laboratory samples were used to train and evaluate …

Late-Night And Early-Morning Train Scheduling With Non-Traffic Hour Maintenance Window In Urban Rail Transit Systems, Yaochen Ma, Hai Yang, Hai Wang

Research Collection School Of Computing and Information Systems

Regular maintenance during non-traffic hours (NTH) is vital for the resilience of urban rail transit (URT) systems, yet an insufficient NTH maintenance window poses a challenge for URT systems in various cities. For instance, the Hong Kong MTR Corporation has noted that the required NTH maintenance time often exceeds the available window, prompting service adjustments such as earlier late-night closures and/or later early-morning starts. To address this challenge, this study develops an optimal scheduling framework that links late-night and early-morning URT services through the NTH maintenance window requirement to maximize public welfare. A Decoupled Optimization Model (DOM) first derives closed-form …

Jme 4110: Drill-Powered Beach Umbrella Anchor, Matthew Barton, Tanin Ramnath, Marquan Bailey, Zachary Van-Horn, Kaelin Mendoza

Washington University / UMSL Mechanical Engineering Design Project JME 4110

A common and potentially hazardous situation faced by beachgoers is when standard umbrella anchors fail to hold during wind gusts, causing the umbrella to potentially go airborne and injure nearby people. Existing anchors require manual operation, leading to inconsistent grip and no resistance to different wind directions. Our project is a motorized three anchor system that drives augers into the sand to ensure a consistent grip and security against the wind.

Jme 4110: Drill Powered Pressure Washer, Kathryn Keele, Ashley Givance, Reagan Grass, Andrew Ellis, Jacob Thebeau

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project focuses on developing a drill-powered pressure washer attachment that connects to a standard cordless drill and garden hose. The device uses the drill as its only power source to pressurize water for cleaning applications. This portable design provides a convenient, low-cost alternative to traditional electric or gas-powered pressure washers.

System Integration And Validation Of The Cal Poly Spacecraft Attitude Dynamics Simulator Mk. Iv, Bricen S. Rigby

Master's Theses

The Cal Poly Spacecraft Attitude Dynamics Simulator (SADS) is an ongoing project that seeks to enable the simulation and validation of sensors, actuators, and control logic related to spacecraft attitude control. The SADS platform rests atop a spher- ical air-bearing device which allows for nearly frictionless rotation in all three axes. The orientation of the platform is controlled by four reaction wheels arranged in a pyramidal configuration. Over the past few years, there have been significant updates to the reaction wheel subsystem, as well as requests for a more capable central com- puter. Therefore, a new system architecture for the …

Constrained Assortment Optimization Under The Mixed-Logit Model, Hoang Giang Pham, Tien Mai

Research Collection School Of Computing and Information Systems

In this paper, we study the assortment optimization problem under the mixed-logit customer choice model. While assortment optimization has been a central topic in revenue management for decades, the mixed-logit model is widely regarded as one of the most general and flexible frameworks for modeling and predicting customer purchasing behavior. The assortment optimization problem is known to be NP-hard to be approximated to any constant factor, even in the unconstrained case. To address this challenge, we first explore the submodularity properties of a simplified version of the objective function to derive novel semi-constant factor approximation solutions for assortment problems under …

Anomaly Management In Unmanned Aerial Vehicles: A Systematic Literature Review, Ivan Tan Wei Han, Christopher M. Poskitt, Lingxiao Jiang, Lwin Khin Shar

Research Collection School Of Computing and Information Systems

Unmanned Aerial Vehicles (UAVs) are increasingly deployed in safety-critical applications such as logistics, surveillance, disaster response, and urban air mobility. While their autonomy enables powerful capabilities, it also introduces vulnerabilities due to hardware faults, software defects, communication failures, and adversarial interference. This survey presents a comprehensive review of research studies closely related to UAV anomalies published between 2015 and 2025, covering 111 papers from academic and industrial sources. We introduce a unified five-pillar taxonomy—anomaly generation, prevention, detection, recovery, and analysis—that organizes existing work across the full anomaly management lifecycle. In contrast to prior surveys that focus primarily on detection algorithms, …

Robust Generator Maintenance Schedule For Frequency-Secure Power Systems, Yang Yang, Qiuzhuang Sun, Jimmy Chih-Hsien Peng, Loon Ching Tang, Zhisheng Ye

Research Collection College of Integrative Studies

Problem definition: Normal operations of a power system require that alternating current frequency be maintained at a nominal value, for example, 50 Hz, whereas severe deviation from this value due to power deficiencies can cause cascading generator trips. Maintaining the frequency requires adequate inertia and frequency regulation reserve, which are primarily provided by online generators. In daily operations, generators due for preventive maintenance must be taken offline, and thus an improper maintenance schedule could jeopardize frequency security, as exemplified by the recent Texas power blackout. However, this natural nexus between frequency security and maintenance has been over-looked largely in the …

Online Planning Of Power Flows For Power Systems Against Bushfires Using Spatial Context, Jianyu Xu, Qiuzhuang Sun, Yang Yang, Huadong Mo, Daoyi Dong

Research Collection College of Integrative Studies

A power station or transmission line can be affected due to bushfires, increasing operation costs. We study a fundamental but challenging problem of planning the optimal power flow (OPF) for power systems under bushfires. We develop a model to capture the stochastic nature of bushfire spread based on Moore’s neighborhood model and propose an online optimization modeling framework to sequentially plan power flows in the electricity network. Our framework assumes that bushfire spread is non-stationary over time and that the spread and containment probabilities are unknown. To address these challenges, we develop a contextual online learning algorithm that treats the …

Monitoring And Short-Term Forecasting Of Atmospheric Air Pollutants Using Deep Neural Networks, Prasanjit Dey

Dissertations

Accurate forecasting of near-surface atmospheric air pollutants such as PM2.5, NO2, SO2, CO, and O3 remains a critical scientific and societal challenge. This difficulty arises from several factors, including nonlinear pollutant dynamics, sparse ground monitoring net works, heterogeneous satellite observations, and strong cross-pollutant interdependencies. Substantial advances have been achieved in temporal deep learning, probabilistic modeling, satellite-based estimation, physics-informed methods, and foundation models. However, these paradigms have largely evolved in isolation. As a result, existing systems are often station-dependent or pollutant-specific and optimized for a single forecasting task. This limits their robustness and generalizability across regions and heterogeneous data regimes.

This …

A Century Of Safer Skies: Statistical Insights Into Aviation Accidents And Death Rates, Abhijeet Regmi

Journal of Aviation Technology and Engineering

The purpose of this study is to determine whether the recent advancements in the technology used for aircraft maintenance and repair have resulted in an increase or decrease in the accident and fatality rates of aviation incidents and accidents. The primary concerns are the extremely low survival rates in aviation accidents and the necessity to determine whether or not the accident and fatality rates are declining in light of recent technological advancements. If the rate is rising, we must prioritize passenger and crew safety more and adhere to tight regulations when performing repairs and maintenance. The data were compared for …

The Open Wiki Of Electrochemical Methods (Owem): A Community-Driven Educational Resource, Anderson Fuller, Devin Rappleye

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The traditional resources for learning electrochemical methods—textbooks, academic literature, and university coursework—remain essential but are limited in accessibility, update frequency, and practical usability. This paper introduces the Open Wiki of Electrochemical Methods (OWEM), an open-access, community-driven platform designed to complement these resources. OWEM organizes content into equations, definitions, methods, tutorials, and supplementary articles, with a heavy emphasis on experimental relevance. A case study on cyclic voltammetry demonstrates how OWEM consolidates foundational theory, lesser-known results, and practical guidance within a continuously maintainable framework to benefit the broader electrochemistry community.

Aspirational Mirrors: A Conceptual Model Of Alumni-Led Near-Peer Outreach For Precollege Engagement In Ocean Engineering, Habibi Palippui, Juswan Sade

Journal of Pre-College Engineering Education Research (J-PEER)

Precollege students in Indonesia, especially in rural and coastal regions, often lack exposure to engineering disciplines due to social, geographic, and informational barriers. This essay proposes a conceptual model of alumni-led near-peer outreach as an affective and culturally grounded mechanism to engage high school students in ocean engineering. Drawing from theories of social similarity, possible selves, and engineering identity, the model conceptualizes alumni as “aspirational mirrors” who influence students not merely through information but also through identification. The model outlines four primary mechanisms—social connection, narrative engagement, aspirational mirroring, and early identity activation—and also accounts for contextual variables such as school …

Detection And Diagnostic Screening Of Breast Cancer: A Systematic Review And Future Frontiers, Lama Yassine, Amira J. Zaylaa

BAU Journal - Science and Technology

A comprehensive evaluation of current and novel diagnostic techniques is necessary since the diagnosis of breast cancer is essential for improving treatment efficacy and raising long-term survival. Evidence from conventional imaging methods including mammography, ultrasonography, and magnetic resonance imaging is combined in this systematic review with advancements in liquid biopsies and current AI-based diagnostic tools. Using specific keywords related to breast cancer, early detection, imaging, biomarkers, and artificial intelligence, a thorough search was conducted in PubMed, Scopus, Web of Science, and IEEE Xplore. Reviews, case reports, and studies unrelated to breast cancer were excluded; only clinical, experimental, and computational research …

Optimize Optical Properties Of Cdte Solar Cell For Pv Applications, Mabrouk Hassan Arhoma

BAU Journal - Science and Technology

In order to to develop thin film heterojunction solar cells, CdTe is one of the most promising absorber materials cells. Electrodeposition CdTe materials solar cell are being focused by Several key researchers. This is due to its direct energy band gap and its high absorption coefficient and the best efficiency obtained for a small-area. In this work CdTe films were electrochemically deposited from aqueous solutions. Different preparative parameters such as growth voltage and heat treatment conditions were optimized. The CdTe layers were deposited at 655, 665, 675, 685 and 695 mV vs SCE. Material characterization were carried out using optical …

Emerging Technologies For Safety Risks Management On Nigerian Road Construction Projects, Ranti Taibat Adebiyi, Mujidat Olubola Babalola, Richard Olushola Olupeka, Ganiyu Amuda Yusuf, Lukman Olarewaju Olorunoje, Amina Damola Amuda

BAU Journal - Science and Technology

High level of safety risk on road construction projects remains a major concern for all industry stakeholders, as safety of workers is paramount to achieving project success. Managing construction safety requires a more comprehensive approach. New technologies have recently emerged to enhance construction safety. This study examines the level of adoption and barriers to the implementation of these technologies in safety risk management on road construction sites in Lagos, Nigeria, with a view to improving the safe delivery of the road projects. A questionnaire was designed and administered to two engineers and one worker randomly selected on each of sixty-one …

Compound Role Of Using Advanced Materials And Design Procedures On Improving The Performance Of Baghdad Buildings Facades, Abeer Qasim Jbur

Al-Esraa University College Journal for Engineering Sciences

The research idea addresses improving the thermal performance of buildings in Baghdad by selecting and employing facade materials to reduce heat gain and energy consumption associated with cooling in a hot-dry climate. The study discusses the pivotal role of facade materials in interacting with solar radiation, heat transfer, and inward thermal transmittance, as well as their capacity to store and release heat in ways that maintain thermal comfort within architectural spaces and reduce reliance on mechanical cooling systems. A range of traditional materials such as stone, earth, and concrete is presented alongside modern materials like high-performance glass and thermal storage …

Current Condition Of The Holy Kadhimiya Shrine Surveying Using A Gpr, Israa Hatem

Al-Esraa University College Journal for Engineering Sciences

This study describes the extensive survey of the Holy Kadhimiya Shrine in Baghdad, Iraq, carried out with the use of a non-invasive geophysical instrument called Ground Penetrating Radar (GPR) to assess the conditions of subsurface and the condition of the infrastructure in the site. The total area of the shrine is 19,575 m² that was systematically studied with the help of internal measures, satellite imagery and radar profiling. The frequency antennas used for the GPR survey were the 250 MHz, 500 MHz, and 800 MHz which have a penetration depth of 1-15 m. Specialized software packages (Ground Vision, Reexplore …

Static Analysis-Based Android Malware Detection (2021–2026): A Systematic Survey And Taxonomy, Ali Hussein Mohammed Ali, Musaab Riyadh Abdulrazzaq

Al-Esraa University College Journal for Engineering Sciences

Android malware is not only increasing in size and sophistication but is also a challenge to be detected on a large scale. Static analysis is popular due to its ability to detect malware without running applications or tracing run-time events. However, features, datasets, labeling methods, and assessment methodology differ, which makes studying performance difficult. This is a systematic study of 78 peer reviewed articles written between 2021 and 2026 regarding the Android malware detection by static analysis. In each of the studies, the current survey cover the following feature source, feature representation and engineering, learning paradigms, datasets and labeling methods, …

Guided Mind Mapping For Enhancing Spatial Thinking In First-Year Architectural Design Studios, Noor Ayad Rashid, Mustafa Kamil Al-Khafaji

Al-Esraa University College Journal for Engineering Sciences

Spatial thinking constitutes a core cognitive ability in early architectural design education, enabling students to interpret, organize, and transform spatial relationships into coherent architectural configurations. Despite its importance, studio practice often indicates that first-year students rely on surface-level representation rather than engaging in structured spatial reasoning, which leads to fragmented compositions and weak spatial coherence. Accordingly, this study investigates the following research question: To what extent can guided mind mapping support the development of spatial thinking in early architectural design studios? A quasi-experimental design was adopted to examine the impact of structured visual–cognitive guidance on students' spatial reasoning. The study …

Multiaxial Stress And Deformation Analysis In Mechanical Structures Under Variable Dynamic Loads, Aqeel Naeem Fareed Al-Khafaji

Al-Esraa University College Journal for Engineering Sciences

Piping supports in gas and process facilities in Iraq are routinely exposed to operational vibration and moderate seismic actions, creating multiaxial, variable dynamic loads that are not fully captured by conventional uniaxial, static design checks. Welded brackets, in particular, are prone to local stress concentration and fatigue at weld toes. This study aims to quantify the multiaxial stress and deformation response of a welded steel pipeline support bracket under variable dynamic loading and to assess the implications for structural integrity and design practice. It was demonstrated by the development and validation of a three-dimensional finite element model of a bracket-pipe …

Real-Time Adaptive Control Of Machining Parameters In Cnc Milling Using An Ensemble Digital Twin And In-Process Vibration Monitoring For Enhanced Surface Integrity, Ali Qasim Abdulwahid

Al-Esraa University College Journal for Engineering Sciences

Achieving consistent surface integrity in CNC milling under varying materials and degraded tool conditions remains a critical challenge because fixed cutting parameters often induce regenerative chatter, accelerate tool wear, and cause surface and subsurface damage. This paper presents an integrated solution that combines an Ensemble Digital Twin (EDT), real-time in-process vibration monitoring, and a hybrid adaptive controller to maintain high surface quality while preserving productivity. The EDT fuses a physics-based milling dynamics model with a recurrent LSTM surrogate through a context-aware meta-learner that weights model outputs by process state (e.g., tool wear, engagement). A compact real-time monitoring pipeline computes a …

Evaluation Of Mimo Antenna Configurations For High Data-Rate Systems, Ammar Abdulimam Abbood

Al-Esraa University College Journal for Engineering Sciences

This paper introduces a new design of cat-shaped antenna in super wideband (SWB) and high data-rate multiple input multiple output (MIMO) systems. The single-element SWB antenna has a wide frequency range of 2.23 GHz up to more than 100 GHz with outstanding bandwidth ratio (BW Ratio = 44.84:1), fractional bandwidth (FBW = 191%), bandwidth dimensional ratio (BDR = 5567) and a peak gain of 9.52 dB. The single antenna was also expanded to 2 × 2 MIMO array to further improve performance on multipath environments. Measurements and simulation show very good results using radiation patterns, isolation, channel capacity loss (CCL), …

Enhancement Of Tribological Behavior Of Rotating Bearings Using Advanced Ceramic Compounds Via Thermal Spray Techniques, Amjid Shihab Abdul Jaleel

Al-Esraa University College Journal for Engineering Sciences

Rotating machines constitute the main part of the most important industrial sectors in Iraq such as oil and gas production, power generation, and manufacturing. The harsh operating conditions however, in the form of high temperatures, corrosive agents and abrasive particulates are causes of premature failure of crucial components such as journal bearings. This study examines the improvement of tribological characteristics of normal steel journal bearings using superior ceramic coating using thermal spray. In particular, atmospheric plasma spray (APS) was used to deposit Alumina-Titania (Al₂O₃–TiO₂) and Zirconia (ZrO₂)coating on A106 Grade B carbon …