Engineering Commons^™

Deep Reinforcement Learning-Enhanced Model Predictive Control Using Dc-Link Energy Modulation For Inter-Area Oscillation Damping In Pmsg-Based Power Systems, Emad M. Elhaji, Shichao Liu, Hicham Chaoui, Osarodion Emmanuel Egbomwan

Electrical & Computer Engineering Faculty Publications

Low-frequency oscillations remain a major concern in modern power systems with increasing penetration of renewable energy sources. Conventional damping methods, such as power system stabilizers and fixed-gain controllers, may not provide sufficient damping for converter-interfaced wind generators under changing operating conditions and disturbances. To address these limitations, this paper proposes a deep reinforcement-learning-enhanced model predictive control (DRL-MPC) framework for damping inter-area oscillations in multi-machine power systems incorporating permanent magnet synchronous generator (PMSG)-based wind turbines. The proposed approach leverages the energy stored in the DC-link capacitor as a fast dynamic buffer to enable supplementary active-power modulation for oscillation damping. A twin-delayed …

Performance Assessment And Design Improvements For An Urban Coastal Detention Basin Under Intensifying Rainfall Extremes, Imiya Mudiyanselage Chathuranika, Agyare Asante, Faeghe Borhani, Xixi Wang, Mujde Erten-Unal, Dalya Ismael

Civil & Environmental Engineering Faculty Publications

Coastal urban areas are increasingly exposed to flooding driven by more frequent and intense rainfall events, rising sea levels, and expanding impervious surfaces. Norfolk, Virginia, a low-lying coastal city with aging stormwater infrastructure, faces heightened vulnerability to these hydrologic pressures. This study evaluates the hydraulic performance of an existing urban detention basin within the Edgewater–Larchmont catchment under 10-, 50-, and 100-year, 2-h design storms using the U.S. Environmental Protection Agency’s Storm Water Management Model (SWMM). Simulations were conducted for both pre- and post-development conditions to assess changes in peak discharge, storage capacity, and water level dynamics. Results show that urbanization, …

Co-Sputtered Cuni Heteroatomic Electrocatalyst For Enhanced 5-Hydroxymethylfurfural Selective Electrochemical Conversion, Moumita Dikshit, Baleeswaraiah Muchharla, Luz Vazquez Rivera, Kapil Kumar, Sunita Sanwaria, Kishor Kumar Sadasivuni, Abdennaceur Karoui, Sandeep Kumar, Adetayo Adedeji, Bijandra Kumar

Civil & Environmental Engineering Faculty Publications

The electrochemical conversion of biomass-derived 5-hydroxymethylfurfural (HMF) represents a promising, economically viable, and environmentally sustainable approach for producing value-added chemicals using renewable energy and in situ hydrogen generated through water electrolysis. However, the electrochemical hydrogenation (ECH) of HMF remains challenging due to the inherently low catalytic activity and selectivity of the electrodes, compounded by competition with the kinetically favored hydrogen evolution reaction (HER) in aqueous electrolytes. In this work, we demonstrate that Cu_xNi_100-x heteroatomic thin films, fabricated via direct current (DC) magnetron co-sputtering, achieve a more than one order of magnitude increase in the HMF to 2,5-Bis-hydroxymethylfuran …

Harnessing Activated Sludge For The Treatment Of Hydrothermal Liquefaction Wastewater: A Proof-Of-Concept Study, Cyrus Li, Jiefu Wang, Meicen Liu, Yi Zheng, Sandeep Kumar, Isamu Umeda, Chandan Mahata, John Norton

Civil & Environmental Engineering Faculty Publications

Although hydrothermal liquefaction (HTL) is the leading technology in converting wet biomass into bioenergy, the treatment of its toxic-laden aqueous phase wastewater presents a major challenge on its path toward commercial viability. This study presents the first-ever assessment of sewage sludge-fed HTL wastewater (SS-HTLWW) treatment and toxic compound removal using municipal activated sludge (AS) by optimizing its cultivation condition. It was found that AS with optimized pretreatment can remove up to 91.2% of the soluble chemical oxygen demand (sCOD) in SS-HTLWW, of which up to 82% can be attributed to biological mineralization and adsorption of sCOD by AS. Conventional bioprocess …

Modeling Hepa Filter Media Performance And Evaluation Of Filtration Leak Test Success, Daniel M. Abraham, Steven J. Eckels, Shahin N. Amiri

Civil & Environmental Engineering Faculty Publications

This research presents a cost-effective microscale modeling analysis of high-efficiency particulate air (HEPA) filter media. We analyzed leak-free and leaking media with known leak sizes. A three-dimensional fibrous model with non-homogeneous fiber diameters (0.2–2 µm) and a packing density of 7.5% was developed to replicate a HEPA filter sheet (H14) microstructure. The objective was to simulate and analyze the pressure drop and collection efficiency of nanofibrous media for aerosol particles with a diameter of d_p ≤ 0.5 µm. The results were compared to prior experimental and theoretical models, exhibiting a high level of agreement with pressure drop and efficiency …

Long-Term Low-Do Operation Changes The Ammonia Oxidizer Community And Oxygen Kinetics, Kester Mccullough, Lilian Mcintosh, Alexandria Gagnon, William Dawson, Hailey Bradshaw, Stephanie Klaus, Dev Hiripitiyage, Belinda Sturm, Diego Rosso, Charles B. Bott, Peter A. Vanrolleghem

Civil & Environmental Engineering Faculty Publications

Low–dissolved oxygen (DO) biological nutrient removal is an attractive option for energy and cost reduction, but it is not common practice as critical outcomes remain uncertain. Open questions include whether ammonia-oxidizer oxygen kinetics are fixed or can adapt to operating conditions; whether low DO increases simultaneous nitrification and denitrification (SND); whether good settling can be maintained; and whether N₂O emissions rise or fall at low DO. In this study, a continuously fed pilot anaerobic/oxic (A/O) process was run with 6.5- to 8.5-day solids retention time (SRT), stable temperature, and constant influent flow, and the operating DO was decreased from 2.0 …

Integrating Self-Organizing Maps And Explainable Artificial Intelligence To Unravel Surface Water-Groundwater Hydrochemical Evolution And Drinking-Water Suitability Controls In A Data-Limited Arid Basin, Hui Tong, Ruizhong Gao, Yinlong Wang, Xixi Wang, Limin Duan, Guoqiang Wang

Civil & Environmental Engineering Faculty Publications

Study region

The Dahei River Basin, located in the semi-arid northern region of China's Great Bend of the Yellow River.

Study focus

This study integrates hydrochemical characterization, stable hydrogen-oxygen isotopes, Self-Organizing Maps (SOM), the entropy-weighted water quality index (EWQI), and explainable ensemble learning (XGBoost-TreeSHAP) to investigate surface water-groundwater evolutionary patterns and identify key hydrochemical contributors to drinking-water suitability in the Dahei River Basin.

New hydrological insights for the region

Waters in the basin are predominantly weakly alkaline and are characterized by HCO₃^--Ca-Mg and HCO₃^--Na facies, indicating the combined effects of carbonate weathering and cation exchange, with …

Adaptive Electric Vehicle Routing And Charging With Deep Reinforcement Learning, Mandana Farhang Ghahfarokhi, Hyoshin Park, Venktesh Pandey, Gyugeun Yoon

Engineering Management & Systems Engineering Faculty Publications

As electric vehicles (EVs) gain popularity, efficient routing and charging solutions remain challenging due to time-dependent travel variability, sparse charging infrastructure, and heterogeneous user preferences. To address these challenges, this paper introduces a decision-support system that integrates three complementary methods: Temporal Multimodal Multivariate Learning (TMML) for real-time characterization of travel time uncertainty, Time-Dependent Shortest Path (TDSP) for reliability-aware route choice, and Deep Q-Network (DQN) reinforcement learning for adaptive charging decisions in sparse infrastructure environments. TMML updates link-level travel time distributions in real-time through Bayesian inference with cluster-based propagation, reducing uncertainties across the network. TDSP leverages these updated distributions to estimate …

A. Vs. I In Ai: Is There A Threshold To "Engineered" Intelligence?, Joshit Mohanty

Engineering Management & Systems Engineering Faculty Publications

Despite artificial intelligence reshaping the world, its development generates uncertainties regarding future capabilities. AI simultaneously exists as an artifact of engineering design and as autonomous intelligence, creating an observer-participant feedback loop. This paper proposes that embodied AI faces a bandwidth-limited intelligence threshold T_h that it arises from B = min(C_sens,C_Act). However, Shannon capacity measures bits while intelligence operates on concepts, necessitating a dual-channel model separating physical bandwidth B_io from representational capacity B_rep. Intelligence emerges as multi-dimensional rather than scalar, with components exhibiting different bandwidth dependencies. Surpassing T_h requires either new sensing methods expanding B, enhanced representational frameworks, or reconceptualization within …

A Three-Stage Causal Root-Cause Diagnostic Protocol For Nonstationary Industrial Time Series Data, Cansu Yalim, Resit Unal, Holly A. H. Handley

Engineering Management & Systems Engineering Faculty Publications

Predictive maintenance (PdM) systems effectively forecast failures, but they often fail to find root causes, particularly when system dynamics change over time. This limitation arises from applying static causal models or decoupled segmentation to handle nonstationary industrial time series. For regime-aware causal diagnostics and interventional effect estimation, we introduce a three-stage time-varying dynamic Bayesian network (TV-DBN) protocol. Using a minimum description length (MDL) objective that connects segmentation to mechanism changes, Stage I jointly infers change points and regime-specific graph structure. Stage II produces a completed partially directed acyclic graph (DAG) by orienting edges within each regime using a combination of …

Information-Theoretic Path Planning For Safe And Adaptive Nanobot Drug Delivery, Nagesh Bheesetty, John H. Park, Sujatha Alla, Winifred M. Lo, Aditya Nimmagadda, Mohamadmahdi Samandari, Jae H. Lee

Engineering Management & Systems Engineering Faculty Publications

We present a safe and efficient path planning framework for nanobot navigation in complex vascular networks, enabling precise drug delivery to hard-to-reach tumor regions such as those found in the lungs. The proposed method introduces a safe and efficient path planning strategy that integrates a utility-based function to balance two key goals: exploring uncertain areas to gather valuable information and avoiding hazardous regions to ensure safe and reliable delivery. We evaluate a simplified swarm-based nanobot navigation scenario using synthetic vascular maps that mimic the structural complexity of lung tumor blood vessels. Environmental uncertainty is modeled from vessel topology, blockage density, …

A Sysml V2 Metamodel For -Ilities: Application To A Digital Twin Complex System, Pacifique Munezero, Holly Ann Heine Handley

Engineering Management & Systems Engineering Faculty Publications

Multidisciplinary knowledge and exchange of information are two of the most important aspects of complex system design within digital engineering and model-based systems engineering (MBSE) environments. The next generation of systems modeling language, SysML v2, developed by the Object Management Group, improves the implementation and maturation of model-based approaches. This article focuses on using SysML v2 to model reusable parameterized templates for nonfunctional requirements, referred to as -ilities, to address how they can be treated with the same rigor as functional requirements and mapped directly and explicitly from the requirements engineering phase within digital engineering and MBSE environments. The selected …

Frequency And Phase Synchronization Of Antenna Arrays With Phase Incoherent Microcontrollers, Harley W. Byrd

University of Kentucky Master's Theses

The construction of phased array antennas has traditionally been an expensive and complex task. It has recently been claimed that it is possible to construct high-performance Wi Fi antenna arrays using inexpensive consumer components. Motivated by some limited data available from online presentations of such devices, this thesis covers an attempt to construct a phased-array Wi-Fi antenna using several ESP32 chips, which have native Wi-Fi modulation and demodulation capabilities. While there are many positive aspects associated with utilizing ESP32 chips for this purpose, a key challenge is the inherent phase incoherence of their internal Phase Locked Loops (PLLs). The approach …

Biomechanical Advancements In Hydroxyapatite, Magnesium-Substituted Hydroxyapatite, And Strontium-Substituted Hydroxyapatite In Clinical And Non-Clinical Studies For Maxillofacial Bone Tissue Engineering: A Review, Elham Zafarrazzaghnia, Stuart Hampshire, Aran Rafferty, Dermot Brabazon, Eamonn Debarra, Maura Kelleher

Articles

Hydroxyapatite (HA) is a bioceramic known for its bioactivity and osteoconductivity, which should make it an ideal candidate for maxillofacial bone regeneration. However, its brittleness limits its suitability for load-bearing applications. Over recent decades, substantial efforts have focused on enhancing its performance, particularly through ionic substitution, including magnesium-substituted HA (Mg-HA) and strontium-substituted HA (Sr-HA). This review summarises the available information on the structural, physical and mechanical properties of facial bones (maxilla, mandible, zygoma and frontal bone). The crystal structure, physical, and mechanical properties and in-vitro biological responses of dense and porous HA, Mg-HA and Sr-HA ceramics are described, with particular …

Network-Aware Airline-Specific Flight Delay Prediction Using Tree-Based Ensemble Models, Mary Dufie Afrane

College of Graduate Studies: Theses & Dissertations

Flight delays pose persistent challenges to the efficiency and reliability of air transportation systems, affecting airlines, airports, regulators, and passengers alike. As traffic demand grows and operational environments become increasingly interconnected, accurately predicting both departure and arrival delays has become crucial for effective planning and mitigation. This study presents a network-aware, airline-specific framework for predicting flight delays in U.S. domestic air transportation systems using tree-based ensemble machine learning models. A large-scale dataset of 1.98 million flights, enriched with weather information, is used to develop predictive models for both departure and arrival delays. To capture the structural and operational complexity of …

Roadway Runoff Impacts To Trout Streams Studies For Ms4 Permit, Jobayed Hossain Badhan

College of Graduate Studies: Theses & Dissertations

Roadway runoff from Georgia Department of Transportation (GDOT) highway infrastructure poses measurable, but temporally constrained threats to cold-water trout ecosystems in northern Georgia. This study investigates temperature and dissolved oxygen (DO) dynamics in three secondary trout streams receiving GDOT roadway discharges, with the primary objective of evaluating compliance with Georgia Rule 391-3-6-.03(6)(ii),(v) under the Municipal Separate Storm Sewer System (MS4) permit framework. Field monitoring was conducted from April 2024 through October 2025 across two consecutive summer seasons using a tiered, multi-instrument approach: YSI ProDSS handheld grab sampling provided regulatory-grade reference measurements; HOBO MX-801 optical DO dataloggers recorded continuous 5-minute-interval temperature …

Effects Of Composition, Nodularity, Pouring Temperature, Inoculation, And Mold Strength On Wall-Movement In Sgi Castings During Solidification And Cooling, Noah Brack

College of Graduate Studies: Theses & Dissertations

The iron-carbon casting alloy known as spheroidal graphite iron (SGI), nodular graphite iron, or ductile iron (DI) experiences complex volume changes during its solidification and cooling as graphite nodules and austenite form. These volume changes result in forces on the mold cavity walls and can deform the mold walls in cases when mold walls lack the strength to resist the deformation. This wall movement can cause the formation of casting defects such as swell, warped part geometry, and shrinkage porosity. Though this phenomenon has been studied in the past, it remains difficult to predict casting wall movement with existing data. …

Investigation Of Dirac‑Like Cones Induced Topologically Protected Wave Propagation (Tpwp) In Solid-Fluid Acoustic Metamaterials: A Combined Numerical And Experimental Study, Humza Khan

College of Graduate Studies: Theses & Dissertations

Topologically protected wave propagation (TPWP) is a unique phenomenon in acoustic metamaterial, where tailored geometries and material properties enable controlled energy absorption and localizations. This study investigates TPWP through the systematic variation of unit cell geometry to capture multiple Dirac-like cone interactions within the Brillouin zone. While prior research had emphasized solid-solid interactions, the present work extends the framework by incorporating a solid-fluid configuration.

The primary objective of this study is to determine the influence of unit cell volume and material selection on  the formation of Dirac-like cones in the Brillouin zone, as well as on the corresponding bandgap characteristics. …

Effect Of Wall Movement On Porosity Formation In Ductile Iron Castings Under Varying Processing Parameters, Shamsul Alam

College of Graduate Studies: Theses & Dissertations

Shrinkage porosity is a major defect that significantly impairs the mechanical properties and overall performance of ductile iron castings. Although graphite formation during solidification induces volumetric expansion, this expansion alone is insufficient to fully compensate for the shrinkage occurring throughout solidification. During the solidification and cooling of ductile iron, multiple phase transformations occur, resulting in dynamic volume changes that exert pressure on mold walls and internal cavities. These pressures can deform mold walls and casting surfaces, leading to defects such as swell and porosity, while also influencing shrinkage formation. This study aims to analyze the mechanisms of porosity formation and …

Dualisme Tujuan Pembebanan Uang Pengganti: Analisis Putusan Angelina Sondakh Di Berbagai Tingkat Peradilan, Valencia Puspa Novandra Ali, Tamsil .

Jurnal Hukum & Pembangunan

Studi ini meneliti perbedaan interpretasi dan penerapan hukuman tambahan berupa restitusi (uang pengganti) dalam kasus korupsi melalui analisis komparatif keputusan Angelina Sondakh di pengadilan tingkat pertama, pengadilan banding, pengadilan kasasi, dan pengadilan peninjauan yudisial. Muncul interpretasi ganda antara memandang restitusi sebagai kompensasi atas kerugian keuangan negara dan sebagai mekanisme untuk menyita keuntungan ilegal. Judex facti menolak penerapan restitusi dengan alasan bahwa tidak terjadi kerugian negara dalam kasus suap dan gratifikasi, sementara judex juris di tingkat kasasi menafsirkan restitusi sebagai instrumen pemulihan aset yang ditujukan untuk keuntungan yang diperoleh secara ilegal. Orientasi konseptual yang bertentangan ini menghasilkan perbedaan signifikan dalam penjatuhan …

High Temperature Diffraction From Aerodynamically Levitated Materials, Chris J. Benmore, Stephen K. Wilke, David Lipke, Richard Weber

Materials Science and Engineering Faculty Research & Creative Works

Aerodynamic levitation combined with laser beam heating has become an established technique for studying the structure of materials at ultra-high temperatures and under non-equilibrium conditions. This article briefly highlights some recent technical and scientific advancements in understanding the relationships between a material's behavior and its structure, investigated using diffraction methods. It focuses on three evolving frontiers: sophisticated sample environments for accessing metastable states and reactive chemistries, high-flux photon and neutron probes to reveal atomic structure, and advanced computational modeling frameworks. Free from contamination, containerless processing (levitation) can minimize heterogeneous nucleation at the interface, enabling access to deeply supercooled melts or …

Analytical And Empirical Data-Driven Risk-Governance Design Across The Different Phases: Creating Informed Policy Adjustments For The Transportation Project Lifecycle, Mariam A. Elazhary

Doctoral Dissertations

"Transportation infrastructure is a critical foundation for economic productivity, yet agencies still face challenges in translating the expanding transportation datasets into defensible, phase-specific risk-governance tools. This dissertation addresses this gap by developing analytical and empirical, data-driven approaches to support risk governance across the transportation project lifecycle. Module 1 uses a panel model with bid-letting data to examine how out-of-state contractor participation affects pre-award competition and to derive entry-governance rules. Module 2 analyzes nonfatal injury data through iterative multiple linear regression and fatality data through association-rule change mining to identify multi-factor safety-risk configurations and develop adaptive safety-governance provisions. Module 3 develops …

Re-Crosslinkable Hyper-Branched Polymer Gels Based On A Transamidation Reaction, Tao Song, Baojun Bai, Thomas P. Schuman

Patents

The present invention generally relates to the field of conformance control in oil fields, particularly to a re-crosslinkable preformed particle gel system, and composition thereof. The composition of the re-crosslinkable preformed particle gel system contains monomers, crosslinkers, a polymer matrix, and additives. Components in the composition for re-crosslinkable preformed particle gel in the present invention have excellent compatibility with each other, and the obtained gel has excellent long term high-temperature resistance property. Different from prior products, in the recrosslinkable preformed particle gel compositions according to embodiments of the present invention, the components that are used to re-crosslink the particle gels …

Advancing Management Strategies For Airport Infrastructure Development: A Holistic Project Delivery And Contractual Perspective, Ramy Ahmed Anwar Ahmed Khalef

Doctoral Dissertations

The airport sector plays a vital role in the US infrastructure. Neglecting the maintenance and improvement of such critical domain poses serious repercussions. Current initiatives within the aviation sector have fallen short in providing substantial quantitative or qualitative support for comprehensive project and risk management processes. This research fills this knowledge gap. The associated objectives include: (1) identifying a holistic set of Design-Build risk factors and providing associated research recommendations; (2) enhancing the understanding of Design-Build (DB) with respect to Design-Bid-Build (DBB) on key risks impacting schedule/cost performance in airport projects; (3) establishing a risk-based benchmarking framework to evaluate schedule/cost …

Students For The Exploration And Development Of Space (Seds) Air Brake Subsystem: High-Altitude Autonomous Apogee Modulator System For High-Powered Rockets (Haamshr), Camden J. Maclean, Matthew Wharton, Nick Revis, Colin Guido

Honors Theses and Capstones

The objective of this project was to research, design, fabricate, and analyze an autonomous apogee modulation air brake system for the University of New Hampshire (UNH) Students for Exploration and Development of Space (SEDS) high-powered rocket as competitors in the Friends of Amateur Rocketry – Oxidizers Uninhibited Tournament (FAR-OUT) competition.

This air brake system would be developed with considerations for full autonomy, structural reliability, and repeatable deployment. The design would also be easily integrated into the existing high-powered rocket airframe and mechanically simple to increase reliability and practical functionality. The final design would be evaluated using finite element analysis simulation …

Generating Concentrated Ring Polymers Through Supercoiled And Open Circle Pdna Isoform Separation, Kelsey E. Hodsdon

Honors Theses and Capstones

DNA can serve as a model polymer due to its high uniformity compared to synthetic polymers. Plasmid DNA (pDNA) in particular offers a well-defined, low-dispersity model for studying topologically uniform systems of a cyclic nature. pDNA has unique isoforms known as open circle (OC) and supercoiled (SC). Using fast protein liquid chromatography (FPLC), specifically anion exchange chromatography (AEX), these OC and SC isoforms can be separated in order to access their unique material properties. Our lab was able to yield the pure SC isoform. However, OC isoform separation has been more challenging. Various difficulties arose during this process, including imaging …

Restoring Tidal Function: Hydrologic And Erosion Controls, On Rare Plant Distribution In New Hampshire Salt Marshes, Nikhila B. Lampman

Honors Theses and Capstones

No abstract provided.

Detection And Management Of Attacks On Synchronized Networks, Michael T. Spearman

Honors Theses and Capstones

The Precision Time Protocol (IEEE 1588) provides sub-microsecond clock synchronization across packet-switched networks and has become foundational infrastructure in 5G fronthaul, industrial control systems, and financial exchanges. Despite its criticality, most deployed PTP networks operate without active security monitoring, and no standardized detection mechanism exists for the class of attacks that deliberately stay below conventional jitter thresholds. This thesis investigates whether hardware-level ptp4l offset logs alone are sufficient to reliably detect two such attacks, slowly wandering packet delay injection and rogue master spoofing, and whether detection can occur before severe synchronization failure.

A hardware-in-the-loop testbed was constructed using two hosts …

Cost-Effective Design Of Home Energy Management System With Pv-Wind And Battery Storage In A Grid-Tied Microgrid, Md Mamun Ur Rashid, Jiefeng Hu, Md Alamgir Hossain, Md Shafiul Alam, Ismot Tasmary Salsabil, Bo Long

Research outputs 2022 to 2026

The rising energy demand and the limited availability of traditional energy sources have driven the search for renewable energy alternatives. Over the past few years, more renewable energy sources and significant efforts have been carried out around the World to decrease carbon emissions in the utility sector. To support this development, microgrids have emerged as a smart component of the future power grid. Microgrids, powered by local energy resources, are the most effective for building the new power grid. In microgrids, an Energy Management System (EMS) is an essential element in scheduling the local energy flows. This paper focuses on …

Assessment Of Advanced Glazing Systems For Building Energy Efficiency In Hot-Arid Climates, Ahmad I. Elshamy, Yousef Elgefly, Yara El-Metwally, Serag Salem

Architectural Engineering

The built environment is considered among the most contributing factors to energy consumption. The building envelope plays a crucial role in determining the building energy consumption, regulating heat transfer and maintaining adequate indoor environmental quality. Hence, optimizing the thermal performance of the building envelope by achieving optimal glazing solutions while fulfilling the Sustainable Development Goal (SDG 7) is the main aim of this research. This study investigates the impact of various facade glazing systems on the building energy performance, focusing on the cooling energy consumption of an office building in a hot arid climate, Cairo, Egypt. The novelty of this …