Digital Commons Network^™

Predictive Current Control Approach For Grid-Integrated Multifunctional Converter Under Source And Load Disturbances, Ravi Kumar Majji, Tirumalasetty Chiranjeevi, Chilukoti Varaha Narasimha Raja, Nagulapati Kiran

Turkish Journal of Electrical Engineering and Computer Sciences

This paper discusses and presents a model predictive control (MPC)-based predictive current control technique for a solar photovoltaic (PV)-integrated grid system during dynamic operation. This control technique employs extension pq (EPQ) theory to estimate reference currents and utilizes an MPC framework for tracking reference currents. Various MATLAB/Simulink simulations were conducted for solar PV generation (source disturbances) and dynamic loading. The results of the OPAL-RT OP4510 real-time simulation are also presented. A multifunctional grid-integrated converter (MFGC) integrates solar active power into the utility grid while achieving unity power factor, reactive power compensation, current balancing, and harmonic suppression. EPQ optimizes mathematical calculations, …

Integrating Augmented Reality Visualizations Into Data Science Notebooks Using Microsoft Hololens 2, Derek Willis

Theses and Dissertations

Data-science notebooks support iterative analysis but are limited to two-dimensional (2D) displays. This work presents an approach to extend such environments with rapid augmented reality (AR) visualization while preserving conventional 2D workflows. An opensource R package was developed to convert notebook objects into three-dimensional (3D) models, export them in the Graphics Language Transmission Format (glTF), and transfer directly to a Microsoft HoloLens 2 via a USB connection for viewing in the native 3D Viewer application. The proposed workflow eliminates manual conversion and transfer steps required by earlier methods. A user study employing a post-session questionnaire indicated that participants found the …

Agentic Synthetic Data Generation For Automated Model Development, Frederick Eugene Diehl

Theses and Dissertations

Large Language Model research has made large strides in capabilities from sentiment analysis to writing code. These advancements have been realized thanks to research into specific capabilities such as prompting techniques. Language models today have demonstrated the ability to create content, transform, and classify. These capabilities are not limited to academic exploration but also found in commercial products that are positioning themselves from application augmentation to personal assistants. These commercial products tend to steer towards single actions such as “summarize this article” or “write a function that performs action...” In parallel research has continued to advance towards more advanced constructs …

A Multiscale Computational Framework Coupling Pulmonary Arterial Blood Flow And Lung Tissue Perfusion, Nigar Sultana, Hangjie Ji, Mette Sofie Olufsen

Biology and Medicine Through Mathematics Conference

No abstract provided.

Adaptive Two-Derivative Runge–Kutta–Nyström Method With Trigonometric Fitting Approach, Nur Nabila Huda, Khai Chien Lee, Nurul Huda Abdul Aziz

Turkish Journal of Mathematics

A fifth-order trigonometrically-fitted explicit two-derivative Runge–Kutta–Nyström method with an adaptive step size strategy, denoted as ATFRKN5, is proposed for efficiently solving second-order ordinary differential equations of the form u^″(x) = f(x, u(x)) that exhibit oscillatory behavior. The order conditions of the method are derived using Taylor series expansion, enabling the construction of two-derivative Runge–Kutta–Nyström schemes up to orders four and five. Trigonometric fitting is applied by incorporating the basis functions e^iλx and e^−iλx, λ ∈ ℝ, allowing the method to adapt naturally to problems with dominant frequencies. …

On Sequences Arising From The Action Of Modular Group, Tuncay Köroğlu, Bahadir Özgür Güler

Turkish Journal of Mathematics

This paper examines the sequences produced by the natural action of specific elements of the modular group on extended rational numbers. The polynomial sequences Pr(c) and Qr(c) are derived from the orbit of the point at infinity under a specific modular transformation. These sequences satisfy linear recurrence relations, which are analyzed using generating functions. The polynomials encode k-Fibonacci numbers, and studying their behavior modulo a fixed integer m reveals notable arithmetic and combinatorial properties. We also explore the connection between these modular actions and Farey graphs, illustrating the hyperbolic transformations as nested geodesic paths in the upper half-plane.

A Module Theoretic Approach To (B,C)-Invertibility, Tuğba Pakel, Burcu Üngör, Handan Köse, Sai̇t Halicioğlu, Abdullah Harmanci

Turkish Journal of Mathematics

In this paper, we introduce and investigate the concept of an (r, f)-inverse in the context of modules, drawing inspiration from the (b, c)-inverse, which is the analogous notion in ring theory. We demonstrate the uniqueness of (r, f)-inverses in modules whenever they exist. We provide some necessary and sufficient conditions for the existence of (r, f)-inverses in modules.

Existence Results And Uniqueness For Some Caputo-Hadamard Fractional Differential Equations Via The Measures Of Noncompactness, Manochehr Kazemi, Mohammad Esmael Samei, Hamid Reza Sahebi, Osman Tunç

Turkish Journal of Mathematics

In this paper, the existence of solutions to Caputo–Hadamard fractional differential equations is investigated using measures of noncompactness and the Petryshyn fixed point theorem. Several new results are established, recovering certain earlier results under weaker conditions. Finally, two illustrative examples are presented.

Proportion Of Nilpotent Subgroups In Finite Groups And Their Properties, João Victor Monteiros De Andrade, Leonardo Santos Da Cruz

Turkish Journal of Mathematics

​This work introduces and investigates the function J(G) = Nil(G) / L(G) , where Nil(G) denotes the number of nilpotent subgroups and L(G) the total number of subgroups of a finite group G. The function J(G), defined on the interval (0,1], represents the proportion of nilpotent subgroups relative to the total number of subgroups, including trivial ones. It serves as a tool for analyzing structural patterns in finite groups, particularly in nonnilpotent families such as supersolvable and dihedral groups. Analytical results reveal the distribution of J(G) values across products of dihedral groups, emphasizing its density over (0,1]. Additionally, a probabilistic …

Optimal Control Of An Inverse Two-Point Boundary Value Problem For A Pseudoparabolic Equation With Samarskii–Ionkin-Type Boundary Conditions, Khanlar R. Mamedov, Tursun K. Yuldashev, Zholdoshbek Zh. Shermamatov

Turkish Journal of Mathematics

This paper investigates an inverse optimal control problem for a pseudoparabolic equation governed by nonlinear control function in a two-point boundary condition. The differential equation is considered under Samarskii Ionkin-type boundary value conditions with respect to the spatial variable x. Necessary optimality conditions are derived, and the associated nonlinear functional equations are analyzed. Using the contraction mapping principle, the existence and uniqueness of the control function are established. Subsequently, the redefinition function and the state function are determined. The convergence of their respective Fourier series representations is rigorously proven.

Close-To-Convexity Properties Of Inverse Hypergeometric Functions, Ijlal Hussain, Wasim Ul Haq, Janusz Sokol

Turkish Journal of Mathematics

The normalized inverse hypergeometric function zF_ν⁻¹(d, e, f; z) = ∑_s=0^∞ A_sz^s+1 is considered, where A_s = (f)_s(ν + 1)_s / (d)_s(e)_s. We aim to provide constraints on d, e, f, and ν under which zF_ν⁻¹(d, e, f; z) belongs to various subclasses of the class of close-to-convex functions. Coefficient characterizations of these families are derived under additional conditions. Some associated operators …

Ricci Solitons On Manifolds With Norden Golden Structure, Bang-Yen Chen, Foued Aloui, Mohammed Nisar, Majid Ali Choudhary

Turkish Journal of Mathematics

​The concept of golden structure is a compelling area with wide-ranging applications. In this paper, we introduce and investigate the notion of Norden golden Ricci solitons. In particular, we investigate Ricci solitons on a Norden golden Riemannian manifold of constant sectional curvature. Furthermore, we explore Ricci solitons and Norden golden Ricci solitons on Norden golden Riemannian manifolds whose potential vector fields are killing, conformal killing, concurrent, or homothetic.

Comparisons Of Some Weighted Mixed Biased Estimators For The Linear Regression Model, Dünya Karapinar, Murat Polat, Ni̇met Özbay, Selahatti̇n Kaçiranlar

Turkish Journal of Mathematics

This paper presents comparative results on the two-parameter weighted mixed estimator, which is a distinct class of estimator defined to address the problem of multicollinearity. The two-parameter weighted mixed estimator is a general estimator that includes the weighted mixed estimator, the weighted mixed Liu estimator, and the weighted mixed ridge estimator. Detailed comparisons among the mentioned estimators are carried out based on the matrix mean square error. Theoretical findings are supported by two numerical examples in addition to a Monte Carlo simulation study.

Improved Oscillation Criteria For A Class Of Neutral Differential Equations In The Canonical Case, Abdulaziz Khalid Alsharidi, Ali Muhib

Turkish Journal of Mathematics

This paper develops an analytical framework based on comparison with first-order equations to derive new oscillation criteria for all solutions of a class of second-order differential equations with multiple delays. These criteria extend and improve upon previously published results. Illustrative examples are provided to validate the theoretical findings and to demonstrate the significance and applicability of the proposed criteria.

Oscillation Properties Of First-Order Difference Equations With Nonmonotone Delays: New Insights And Criteria, Emad Attia, George Chatzarakis

Turkish Journal of Mathematics

In this paper, we examine the oscillatory behavior of the first-order linear delay difference equation Δy(n) + p(n) y(τ(n)) = 0, n ∈ ℕ₀. It is known in the literature that, for any C > 0, the condition lim sup_n→∞ ∑_i=τ(n)ⁿ p(i) > C, with τ(n) nonmonotone, is not, in general, sufficient to establish the oscillation of the difference equation. We prove that, for certain classes of difference equations, the aforementioned condition is sufficient to ensure the …

On The Number Of Exact Factorization Of Finite Groups, Jesus Alonso Ochoa Arango, Maria Angelica Umbarila Martin

Turkish Journal of Mathematics

In this work, the function f2(G), which counts the number of exact factorizations of a finite group G, is studied. The value of  f2(G) is computed for several well-known families of finite groups, and an asymptotic expression is derived for the number of exact factorizations of the alternating group A2n .

2026 Revised Draft Final Bpsou Backfill And Cover Material Quality Assurance Project Plan (Qapp), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Urban Conflagrations: Structural Ash And Soil Metal(Loid) Contamination After California’S Eaton And Palisades Fires, S. Anselme Dossou, Leon Kelly, P. Louis Lu, Robin Jones, Oliver O'Donnell, Justin St. P. Walsh, Daniel D. Richter

Art Faculty Articles and Research

In the weeks after California’s Eaton-Palisades wildfires, structural ash of burned homes and soils from yards and curbsides were sampled for analysis of Pb, As, and eight metals from 32 burned residences. About six months after fires and after US Army Corps of Engineers’ Phase 2 cleanups removed 15 cm from structural ash footprints, 17 properties were resampled within about a meter of original sampling sites. Concentrations of metal(oid)s in structural ash and residential soils varied between and within properties with significant spatial and temporal patterns. Lead concentrations were highest in structural ash and soil of yards of select pre-1970s …

Modeling Velocity Distributions Of Interstellar Neutral Hydrogen In The Heliosphere, Lucas Robert Dyke

Dartmouth College Ph.D Dissertations

As interstellar neutral hydrogen (ISN H) is the most abundant neutral element in the helio- sphere, the region within which the solar wind interacts with the portion of the interstellar medium through which our solar system moves through, it is integral that we aim to under- stand its many properties and interactions within this region. This work details the synthesis and use of a model of ISN H, using trajectory methods to backtrace from a target point at a radial distance of 1 au where explorer probes like Interstellar Boundary Explorer (IBEX) and Interstellar Mapping and Acceleration Probe (IMAP) reside. …

A Governance-Aware Multi-Agent Framework For Enhancing Fairness & Temporal Accuracy In Disaster Response Systems, Md. Ashfaqur Rahman

Theses and Dissertations

Large Language Models (LLMs) have demonstrated significant potential in disaster-response decision support, however, their deployment in high-stakes humanitarian settings raises critical concerns regarding factual reliability, fairness, temporal validity, and governance compliance. Hallucinated outputs, demographic bias, and outdated recommendations can directly impact vulnerable populations and undermine public trust. This dissertation proposes a governance-aware multi-agent framework designed to enhance fairness and temporal accuracy in disaster-response systems through structured Retrieval-Augmented Generation (RAG), verification-driven orchestration, and adaptive correction mechanisms.The proposed architecture decomposes response generation into specialized agents responsible for real-time retrieval, fact-checking, bias auditing, temporal validation, threshold-based correction, and monitoring. By embedding governance constraints …

High-Surface-Area Ficus Leaf-Extracted Cuo-Zno-Nio Ternary Nanocomposites For Rapid Adsorption-Assisted Uv-A Degradation Of Direct Blue 15, Kafa’A H. Ali, Mohammed A. Atiya, Ahmed K. Hassan

Karbala International Journal of Modern Science

Direct Blue 15 (DB15) is a long-lasting synthetic dye that pollutes water and is difficult to remove during wastewater treatment. Conventional treatments fail to remove DB15 adequately due to rapid electron-hole recombination, which necessitates photocatalysts with reduced recombination rates for effective dye removal. The study aims to synthesize and evaluate a CuO-ZnO-NiO ternary system as an integrated adsorption and UV-A photocatalysis platform for DB15 removal. Ficus leaf-extracted CuO-ZnO-NiO nanocomposites with four Cu:Zn:Ni ratios (1:1:1, 1:1:2, 1:2:1, 2:1:1) were prepared by co-precipitation, followed by extensive chemical and physical characterization and dye-removal performance measurements. The CuO-ZnO-NiO nanocomposite exhibited hexagonal zinc oxide, cubic …

Uncovering The Impact Of Youtube's Hidden Algorithm On Its Users, Oscar Perez

COD Library Student Research and Award Symposium

YouTube is a well-known platform that offers users endless hours of news, entertainment, and education. This research seeks to understand how the algorithm functions and uncover the effects of allowing a system to curate content for viewers. The research combines academic sources with fieldwork to understand the impact of YouTube's algorithm.

Faculty Sponsor:  Professor Jacqueline McGrath

Energy-Efficiency Optimization And Comparison For Irs-Assisted Bidirectional Relay And Direct Transmissions, Caixia Cai, Jiayao Zhang, Fuli Zhong, Han Hai, Yayu Yang, Sunil Chinnadurai, Anwer Al-Dulaimi

All Works

Intelligent reflecting surface (IRS) has emerged as a promising technique for achieving high-transmission rate and low-power consumption transmission to meet the requirements of future beyond 5G and 6G communication. In this paper, we optimize and compare the energy-efficiency (EE) of IRS-assisted bidirectional relay transmission (BRT) and bidirectional direct transmission (BDT). In specific, we firstly consider and give the IRS-assisted BRT and BDT models. Then, we give the analyses of signal transmission models and EE for both IRS-assisted BRT and BDT. In addition, to optimize the EE, we give the joint optimization problems for both IRS-assisted BRT and BDT, which incorporate …

Development Of Dual-Stimuli Responsive Polymer-Coated Gold Nanoparticles And Their Surface Engineering Via Polyelectrolyte Layer-By-Layer Assembly, Buddhini Chathurangi Nugaduwa Vithanage

Dissertations - ALL

The modification of nanoparticles with combinations of low critical solution temperature (LCST) polymers and polyelectrolyte (PE) layers is studied. Three n-isopropylacrylamide-co-acrylamide polymers were synthesized in which charges could be varied from neutral, to negative or positive by way of incorporating poly acrylic acid (pAAc) or poly 4-vinylpyridene (p4VP) units. Polymerization centered around a disulfide initiator, which when reduced produced two polymer chains and a convenient linkage to gold NPs (NPs). The resulting LCST-NPs conjugates possessed sharp phase changes at critical temperatures (TC), while the incorporation of pAAc or p4VP allowed for tuneable charges and pH sensitivity. Studies with 1H-NMR and …

Climate Policy Uncertainty And Housing Prices: Analyzing Bidirectional Transmission Across U.S. Metropolitan Areas, Sourav Batabyal, Alper Gormus

Finance and Economics

This study examines the relationship between climate policy uncertainty (CPU) and residential housing prices across U.S. metropolitan areas using the U.S. CPU index developed by Gavriilidis in 2021 and monthly S&P CoreLogic Case-Shiller Home Price Indices, covering January 1991 to May 2024. Employing a Fourier-augmented Toda–Yamamoto causality framework that accounts for both abrupt and gradual structural breaks, we document significant CPU → housing prices transmission in multiple metropolitan markets, with bidirectional transmission dynamics emerging in Los Angeles, New York, San Diego, and San Francisco, as well as at the U.S. national level. The results reveal substantial spatial heterogeneity across various …

The Prospect Of F.E.W. Resources: How Food, Energy, And Waste Management Workforce Programs Address Global Equity And Sustainability, Quincy P. Biddle

Student Theses 2015-Present

As a global society, the issues affecting a specific city or country are no longer isolated; instead, they impact other places in myriad ways. Over the past few decades, environmental degradation and economic inequality, both within and between countries, have caused shortages of necessities like food and water, inadequate access to safe energy sources, and increased pollution, impacting people’s prosperity and the well-being of the planet. It is of global interest to remediate these issues for the betterment and progress of society, and thus, an approach to addressing these complications collectively and comprehensively is of utmost importance. This paper investigates …

Secondhand Or Second-Class? Environmental Injustice In Global Textile Waste Trade, Wendy S. Escalante

Student Theses 2015-Present

This paper addresses the issue of textile waste dumping, specifically how secondhand clothing exports from the Global North create environmental, social, and public health burdens in the Global South. The study focuses on case studies in Chile’s Atacama Desert, where shipments of used clothing overwhelm local waste infrastructures and worsen patterns of environmental injustice. Chapter 1 describes the global flows of textile waste, including trade volumes, landfill accumulation, and the impacts of discarded clothing on ecosystem services such as clean water, fertile soils, and breathable air, alongside health risks from microplastic pollution, toxic runoff, and respiratory hazards from textile fires. …

Friedel–Crafts Addition Of 3-Alkylated Indoles To Aldehydes: 2-Hydroxyalkylation Promoted By Trimethylsilyl Trifluoromethanesulfonate, Eric Zhou, Helen Xia, C. Wade Downey

Chemistry Faculty Publications

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, 3-alkylated indoles undergo Friedel–Crafts silyloxyalkylation when treated with nonenolizable aldehydes. The reaction is general across a wide range of aromatic aldehydes and tolerates a variety of N-alkylated indoles. Deprotection of the silylated product occurs under standard conditions, and in certain cases the initial TMS-protected product can be isolated in high yield.

How Ai Governance Differs Between Regime Type, Jackson T. Guillou

Honors Theses

This thesis will examine how artificial intelligence (AI) regulation and development differ across political regime types, arguing that governance outcomes are fundamentally shaped by institutional political structures. This thesis will draw on comparative frameworks analyzing democratic and authoritarian systems. This thesis will also include case studies of the European Union, the United States of America, China, and Russia. The study finds that democratic regimes tend to emphasize transparency, accountability, and rights-based regulation of AI. This often results in slow regulation of AI, but it is more ethically legitimate and constrained. In contrast, authoritarian regimes prioritize centralized control, strategic coordination, and …

Stridevision: Automated Detection Of Running Form Deviations From 2d Pose Estimation And Machine Learning, Paulina Eguibar Ortega

Honors Theses

Running gait analysis plays a critical role in injury prevention and performance optimization, however, existing approaches often rely on specialized laboratory equipment or wearable sensors with limited interpretability. Recent advances in computer vision, particularly 2D human pose estimation, enable markerless motion analysis from standard video. However, progress remains constrained by the lack of publicly available datasets designed for running form analysis.

In this work, we introduce a preliminary dataset and benchmark for stride-level running gait analysis. The dataset consists of 73 treadmill running videos from 15 participants with varying experience levels, annotated with over 4,600 stride-level labels across multiple biomechanical …