Physical Sciences and Mathematics Commons^™

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.

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.

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 …

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.

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 .

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.

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.

Assessing Vegetation Health Following The 2014 Carlton Complex Fire Using Remote Sensing, Rachael Sv Pentico

2026 Symposium

Climate change, combined with decades of altered fire regimes and fire suppression, has increased fuel accumulation across western U.S. forests, contributing to more frequent, larger, and more intense wildfires. Remote sensing offers an effective approach for analyzing these large-scale fire events and their ecological impacts, as satellite imagery enables affordable, accessible, and reproducible monitoring of vegetation change across broad spatial and temporal scales. This study examined the 2014 Carlton Complex Fire in the Methow Valley, Washington. Burning 265,108 acres, it was the largest wildfire in Washington State history at the time and caused extensive agricultural and forest damage. Post-fire vegetation …

Latent Transition Analysis: A Statistical Method For Identifying Underlying Subgroups Over Time, Holmes Finch

Perspectives on Early Childhood Psychology and Education

Researchers working in early childhood research are often interested in assessing change over time in multiple variables. In addition, they may wish to ascertain whether there exist subgroups in the data with respect to these variables, and whether/how membership in these groups is related. Latent transition analysis (LTA) provides such researchers with a useful tool for investigating questions around such groups, including their composition, frequency, and the likelihood of moving from one to another at different points in time. The purpose of this manuscript is to provide a full demonstrate of LTA and show how it can be used to …

A Tutorial For Identifying And Comparing Change Points In Developmental Trajectories, Holmes Finch

Perspectives on Early Childhood Psychology and Education

Researchers in a variety of social science fields work with sequential data, such as measurements made over time. In some instances, one or more of the moments (e.g., mean, variance) of the series may change abruptly at some point in the sequence, yielding what is known as a change point. There is a broad literature describing methods for changepoint detection. Researchers working with multiple sequential series containing change points may be interested in comparing the locations of these changes. The purpose of this manuscript is to demonstrate how a researcher can detect changepoints and compare changepoints between two or more …

Using Multilevel Modeling To Understand Nested Data, Holmes Finch

Perspectives on Early Childhood Psychology and Education

Researchers in the social sciences often work with nested data, in which individuals are collected in higher level clusters. For example, educational research often involves working with samples in which students are nested within schools. Standard data analyses, such as regression and analysis of variance (ANOVA), yield statistically biased results when this nested structure is ignored. One widely used and effective approach for handling such nested data is multilevel modeling. The purpose of this manuscript is to review the basics of multilevel modeling and to provide the reader with a fully worked example in which the analytic approach and results …

Using Effect Sizes, Confidence Intervals, And The Bayes Factor To Better Understand The T-Test, Analysis Of Variance, And Regression Results, Holmes Finch

Perspectives on Early Childhood Psychology and Education

Null hypothesis testing is a widely used paradigm for assessing research hypotheses across the social sciences. Despite their ubiquity, researchers have discussed a number of problems and limitations to hypothesis testing and have suggested alternatives that might provide greater depth and explanation of research results. The purpose of this paper is to describe the use of several such alternatives and to show how they can be integrated with one another and with null hypothesis testing in order to provide a more holistic view of research hypotheses.

A Gis Analysis Of The Relationship Between Ndvi Value, Slope, And Aspect Of The Terrain Of The Prairie Restoration Project, Basil Lund

2026 Symposium

The Prairie Restoration Project (PRP) encompasses 115 acres of land on the west side of the EWU campus. The goal of the PRP is to restore what was once a section of wheat farm back to its original Palouse prairie state. Here, I am using publicly available satellite data to examine some potential variables affecting the health of wheat plants planted in the years 2009 to 2017. I have used 4-band aerial imagery to create a map of NDVI values within the bounds of the PRP, which visualizes the near-infrared wavelengths that are reflected by healthy, chlorophyll-rich plants. I have …

Λ-Fold Near-Factorizations Of Groups, Donald L. Kreher, Shuxing Li, Douglas R. Stinson

Michigan Tech Publications

We initiate the study of λ-fold near-factorizations of groups with λ>1. While λ-fold near-factorizations of groups with λ=1 have been studied in numerous papers, this is the first detailed treatment for λ>1. We establish fundamental properties of λ-fold near-factorizations and introduce the notion of equivalence. We prove various necessary conditions of λ-fold near-factorizations, including upper bounds on λ. We present three constructions of infinite families of λ-fold near-factorizations, highlighting the characterization of two subfamilies of λ-fold near-factorizations. We discuss a computational approach to λ-fold near-factorizations and tabulate computational results for abelian groups of small order.

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 …

Oregon State Rank Assessment For Wiens' Dwarf Mistletoe (Arceuthobium Abietinum Ssp. Wiensii), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Wiens' dwarf mistletoe (Arceuthobium abietinum ssp. wiensii) using NatureServe methodology, 2026.

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 …

Llms In Compiler Construction, Raffi Khatchadourian

Open Educational Resources

These lecture slides survey the use of large language models (LLMs) in compiler construction for a graduate compiler course (CSc 81010). They situate LLMs across the compiler pipeline and examine representative work: foundation models trained on LLVM IR and assembly (Meta's LLM Compiler), LLM-driven code optimization, binary decompilation (LLM4Decompile), and LLM-assisted automated refactoring—alongside the challenges of applying probabilistic models to tasks that demand correctness. The slides are a self-contained HTML (W3C Slidy) deck with editable Pandoc Markdown source. Part of a two-session unit on advanced compiler topics; see also "Deep Learning Compilers."

Deep Learning Compilers, Raffi Khatchadourian

Open Educational Resources

These lecture slides introduce deep learning compilers for a graduate compiler-construction course (CSc 81010). Building on the classical compiler pipeline, they show how modern machine-learning systems compile tensor programs: static tensor and type analysis (illustrated by a WALA/Ariadne-based refactoring of imperative TensorFlow code to graph mode), MLIR-based end-to-end compilation with IREE, and the PyTorch 2.x stack—TorchDynamo graph capture, AOTAutograd, PrimTorch operator decomposition, and TorchInductor lowering to Triton (GPU) and C++/OpenMP (CPU). The slides are a self-contained HTML (W3C Slidy) deck with editable Pandoc Markdown source. Part of a two-session unit on advanced compiler topics; see also "LLMs in Compiler Construction."

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. …

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

Shaped By The Feed: Big Data, Identity And Power, Ana Paula Andrada

COD Library Student Research and Award Symposium

I explored how big data and algorithms shape the way we think and interact at an individual and societal level. This started from things I kept noticing in everyday life. Through my research, I learned how the personalization and predictability in feeds can reinforce beliefs, limit our critical thinking, deepen polarization and threaten our freedom.

Faculty Sponsor:  Professor Aleisha Balestri

A Statistical Analysis Of Current And Future Hurricane Activity In The North Indian Ocean, Basil Lund

2026 Symposium

A hurricane is defined as a tropical storm with winds sustained at 74 mph or greater. I examined major (category 3 and above) hurricane activity over the North Indian Ocean from the years 1972-2019 as reported by Colorado State University Hurricane Forecast Archive. Using RStudio, I conducted a binomial analysis of the CSU dataset to calculate probabilities of zero to ten years with one or more major North Indian Ocean hurricanes in the next decade. I conducted a geometric analysis to determine probabilities associated with waiting periods for the next year with a major hurricane, as well as a Poisson …

A Geotechnical Analysis Of Mid-Slope Soil Sample Pp-15 From The Palouse Prairie Restoration Project In Cheney, Wa, Basil Lund, Robin Roose, Chloe Jensen

2026 Symposium

The Palouse is an Inland Northwestern ecoregion with loess hills created by aeolian processes related to Pleistocene glacial events. Eastern Washington University’s Prairie Restoration Project aims to restore a 120-acre site located in Cheney, Washington. EWU is gradually seeding bunchgrasses and perennial forbs to increase biodiversity of the site, which will be used for educational and recreational purposes. The objective of this project was to determine to what extent the engineering properties of soil on the site varies along a slope. To determine if location on the slope affects soil properties on the site, we sampled and performed a geotechnical …

Analyzing Surface Water And Groundwater Interactions From Pfas Contamination In The West Plains Region Of Spokane County, Jerusha R. Hampson

2026 Symposium

The West Plains region of Spokane County has been significantly impacted by PFAS contamination due to the decades-long use of aqueous film-forming foam (AFFF) for firefighting training at both Fairchild Air Force Base (FAFB) and the Spokane International Airport (SIA). Groundwater contamination is significant, but surface waters are impacted by the contamination as well. Groundwater flows to the north and east, meaning surface water bodies that make up the northern and eastern boundaries (Deep Creek, Hangman Creek, and the Spokane River) can be impacted by PFAS contamination. The West Plains aquifer system is complex but combining data about aquifer flow …

Preliminary Geologic Assessment And Pfas Occurrence In Western Cheney, Washington, Sydney Frandsen

2026 Symposium

In 2021 Cheney Water Well #5 was closed due to toxic per- and polyfluoroalkyl substances (PFAS) levels above the current State Action Limits and the National Drinking Water Protection Act (https://www.cityofcheney.org/207/Water), which is a concern since PFAS has been associated to types of cancer, birth defects, and other negative human and environmental health concerns (https://doh.wa.gov/communityand-environment/contaminants/pfas). The City of Cheney also tested two downgradient deep-groundwater-wells (Cheney wells #6 and 7) and halted investigation due to the wells being below state and federal drinking water standards. However, a local resident’s shallow groundwater well tested to be above federal and state levels of …

Relation Subspaces In Vertex Operator Algebras: Residue Generators For O_N^\Circ(V) And Intersections With (L(−1) +L(0))V, Junghyun Kim

Undergraduate Research Journal

We study the relation subspace 𝑂◦𝑛 (𝑉) that appears in the definition o f the level-𝑛 Zhu algebra 𝐴𝑛 (𝑉) = 𝑉/𝑂𝑛 (𝑉), where 𝑂𝑛 (𝑉) = 𝑂𝐿 (𝑉) + 𝑂◦𝑛 (𝑉) and 𝑂𝐿 (𝑉) =(𝐿(−1) + 𝐿(0))𝑉. Using residue calculus, we introduce operators 𝑅𝑛,𝑘 that encode the circle products 𝑢◦𝑛 𝑣 and prove explicit change-of-generators formulas between the standard generators (𝑢−𝑚1)◦𝑛 𝑣 and the residue generators 𝑢 𝑅𝑛,0𝑣, together with a binomial inversion. These identities provide a practical framework for computing 𝑂◦𝑛 (𝑉), especially in strongly generated VOAs. As progress toward understanding the overlap 𝑂◦𝑛 (𝑉) ∩ 𝑂𝐿 (𝑉), …

Identifiability, Sequentiality And Infinity, Jose L. Menaldi

Mathematics Faculty Research Publications

Abstract: A definition of identifiable-sets is used with sequential analysis to establish a realm of mathematics. Within this imaginary world, a specific consonant between infinite sets and sequentiality is reached.  This consonant allows some mathematical constructions to model pieces of the reality, based on dual philosophy and physics itself.  There is an effort made to render this understandable for the scientific community.