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Existence Of Positive Periodic Solutions For A First-Order Semilinear Functional Differential Equation With An Iterative Source Term, Ahlème Bouakkaz, Rabah Khemis

Turkish Journal of Mathematics

In this paper, we will establish the existence of positive periodic solutions for a class of first order iterative functional differential equations by using a powerful and effective technique based on the Krasnoselskii fixed point theorem together with some useful properties of a Green's function. The obtained results that complement some previous works, are illustrated with an example.

Simplicity In Le-Semigroups Via Partitions Of Full Words, And Its Applications To Regularity Conditions Induced By Linear Inequalities, Nareupanat Lekkoksung

Turkish Journal of Mathematics

The concept of simplicity in le-semigroups has been used to characterize the coincidence of ideal elements and to study Khayopulu–Green’s relations. Several types of simplicities are known, including two-sided simplicity, left simplicity, right simplicity, bisimplicity, quasisimplicity, and biinterior simplicity. A natural question arises: are there further notions of simplicity for le-semigroups? If so, how are they related? By employing the notion of partition ideal elements, we observe that several potential simplicities have not yet been explored. In this paper, we introduce new forms of simplicity in le-semigroups defined via partitions of full words, and we investigate the …

On The Semigroups Of Order-Preserving And Orientation-Preserving Full Contraction Mappings On A Finite Chain, Gonca Ayik, Hayrullah Ayik

Turkish Journal of Mathematics

Let OPCT_n (OCT_n) denote the semigroup consisting of all orientation-preserving (order-preserving) full contraction mappings on the finite chain X_n = {1 < ··· < n}, and let OPDCT_n (ODCT_n) denote the subsemigroup of OPCT_n (OCT_n) consisting of all order-decreasing transformations. The purpose of this paper is to determine the cardinalities of OPCT_n, OPDCT_n, N(ODCT_n), and N(OPDCT_n), and to identify generating sets of minimal size, thereby determining their ranks. Moreover, the number of idempotents of OPDCT_n is determined.

A Geometric Property Characterizing The 3d-Generalized Clothoids, Pascual Lucas, José-Antonio Ortega-Yagües

Turkish Journal of Mathematics

In this paper, we study 3D-generalized clothoids, defined as curves for which there exists another distinct curve, with proportional arclength parameter, such that the Darboux lines of both curves at corresponding points are the same. We prove that these curves are those for which the ratio of torsion and curvature τ/κ is a linear rational function of the arclength. We also show that any 3D-generalized clothoid can be constructed from a rectifying curve, which is of constant curvature in the case of a 3D-clothoid.

Multiplicative Lorentz Matrix Multiplication And The Motion On Multiplicative Lorentz Plane, Osman Keçi̇li̇oğlu, İlayda Durmaz, Hali̇t Gündoğan

Turkish Journal of Mathematics

In this paper, we define the multiplicative determinant for general n×n matrices, extending previous studies that were limited to lower-dimensional cases. Additionally, we introduce a novel matrix multiplication operation based on the multiplicative Lorentz inner product and conduct a thorough investigation of its algebraic properties. Furthermore, we explore rotational and reflectional transformations in the two-dimensional multiplicative Lorentz space L^*₂, supported by illustrative examples of these geometric motions.

Investigation Of The Behavior Of Biparametric Potentials Associated With The Laplace-Bessel Differential Operator In Weighted Lebesgue Spaces, Çağla Seki̇n

Turkish Journal of Mathematics

In this article, we investigate the mapping properties of potential-type operators of the form J^α_β = (E + (−Δ_ν)^β/2)^−α/β, (β, α > 0), where Δ_ν is the Laplace-Bessel differential operator. We establish norm inequalities that describe the boundedness of the operator J^α_β from L_p,ν to L_q,ν under suitable conditions on α, β, p and q. The results extend and unify the known estimates for classical potential operators. In particular, the cases β = 1 and β = 2 correspond to the modified Flett and Bessel potentials, respectively.

On Fredholm Type Integral Equations In H\"{O}Der Spaces: Existence Of Solutions, Yasemi̇n Başci, Adi̇l Misir, Süleyman Öğrekçi̇

Turkish Journal of Mathematics

In this study, we investigate the existence of solutions for a quadratic integral equation of the Fredholm type. The analysis is conducted on a finite interval bounded by two arbitrary constants, where the unknown function is associated with a prescribed kernel and two operators satisfying specific regularity and boundedness conditions. The methodological framework of this work is built upon the classical Schauder fixed point theorem, complemented by the structural properties of Hölder spaces. The results obtained not only encompass but also extend several previous contributions in the literature, as the discussion is carried out within a generalized setting over the …

Exploring Topological And Game-Theoretic Properties Of Selective Covering Bispaces, Selma Özçağ

Turkish Journal of Mathematics

This paper considers set selectively star countable chain condition in a bitopological setting, exploring its fundamental topological properties and its relationships with the existing selective covering properties. Furthermore we investigate a game-theoretic characterizations of the selectively countable chain condition property in bitopological spaces.

The Killing Magnetic Curves In The Anti-De Sitter Space H31, Uğur Dursun

Turkish Journal of Mathematics

In this paper, we study space-like, time-like and light-like Killing magnetic curves derived from Killing magnetic vector fields of the anti-de Sitter space H³₁ by using the half-space model H³₁ of H³₁. We find the first integrals of the system of nonlinear differential equations that describe the Killing magnetic curves corresponding to some Killing vector fields of H³₁, and then we give some particular solutions to obtain space-like, time-like and light-like magnetic curves of H³₁. Also, we calculate the curvature and torsion of some space-like and time-like …

A Non-Newtonian Approach To Screw Motion And Dual Numbers, Esra Parlak, Zehra Özdemi̇r

Turkish Journal of Mathematics

In this paper, we define multiplicative dual numbers, multiplicative dual vectors, scalars, and vector products associated with the multiplicative dual numbers. We give the base elements of multiplicative dual elliptic quaternions and their operational properties. We explain the rotation and translation motions in multiplicative dual elliptical quaternions. We provide the matrix representations of the screw motion using multiplicative dual elliptical quaternions. Thanks to these multiplicative dual elliptical quaternions, we explain the screw motion along with rotation and translation with theorems and proofs. We visualize this screw motion with mathematical programs by applying screw-ruled surfaces.

Characterization Of Physical And Structural Properties In A Quaternary Li2o-B2o3-Bi2o3-V2o5 Glass System, Alan Ikram Ahmed, Mowfaq Jalil Ahmed

Polytechnic Journal

Borate-based glasses modified with alkali oxides are of considerable interest due to their tunable structural and optical properties, which are important for optical and energy storage applications. In this work, glasses with a novel nominal composition of xLi2O-(75-x) B2O3—20Bi2O3—5V2O5, in which (x ¼ 5, 10, 15, 20, 25 mol %) were produced using the traditional melt-quenching technique to investigate the effect of substituting the glass former B2O3 with the modifier Li2O. The structural and optical properties were examined by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and UV—visible spectroscopy. The XRD analysis confirms the amorphous nature of the samples produced. …

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.

Long-Term Variability Of Air Quality And Greenhouse Gas Emissions From Rice Crop Burning In Punjab During 2012–2020, Harsimranjit Kaur Romana, Dericks Praise Shukla, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

Punjab, India's primary rice and wheat production hub, has witnessed rapid expansion of paddy cultivation over the past two decades, driven by minimum support price incentives, changes in government policies, alignment of sowing with the monsoon season and the adoption of high-yielding varieties. This transition has intensified groundwater extraction and shortened the fallow period between rabi and kharif crop seasons, reducing the window between rice harvesting and wheat sowing, leading to widespread open-field burning of rice residue and recurrent post-monsoon air-quality deterioration across the Indo-Gangetic Plain. Despite numerous short-term or single-pollutant assessments, a spatially resolved, multi-pollutant and multi-decadal evaluation linking …

On Edible Food Recovery: Integration Of Local Agriculture Into Santa Clara County Food Recovery Networks, Anna Keenan, Caitlin Delamora, Jenna Martinez, Vansh Malik

Environmental Studies and Sciences Senior Capstone

Santa Clara County (SCC) produces over 50 million pounds of surplus food, yet 31% percent of county residents are reported to be at risk of food insecurity, lacking reliable access to proper, affordable nutrition. Additionally, SCC produces approximately 40,000 tons of food waste annually. Food waste decomposes in landfills, producing greenhouse gas emissions, posing a pressing public health and environmental issue. California’s food waste law (SB 1383) addresses this challenge. We aimed to provide actionable insights that enable local farmers to donate more surplus produce, identifying ways to divert food loss from local farms to recovered food hubs, turning potential …

Predicting Tart Cherry Stem Water Potential Using Uav Multispectral Imagery And Environmental Data Via Symbolic Regression, Anderson L. S. Safre, Alfonso Torres-Rua, Kurt Wedegaertner, Brent Black, Brennan Bean, Burdette Barker, Matt Yost

Civil and Environmental Engineering Faculty Publications

Tart cherry is an important fruit crop in Utah, where irrigation is essential due to arid conditions. Precision irrigation requires reliable indicators of plant water status, and stem water potential (Ψ_stem), is among the most sensitive though labor-intensive and spatially limited. This study develops Ψ_stem estimation models using high-resolution multispectral Unmanned Aerial Vehicle (UAV) imagery combined with meteorological and soil moisture data, applying Symbolic Regression (SR). Results show a stronger correlation between optical bands and Ψ_stem during the pre-harvest period. Among 85 vegetation indices, the Red Chromatic Coordinate (RCC) index performed best (R² = 0.67). …

Monthly Progress Report Butte Priority Soils Operable Unit Consent Decree Partial Remedial Design/Remedial Action And Operation And Maintenance, Josh Bryson

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Why Text Prevails: Vision May Undermine Multimodal Medical Decision Making, Siyuan Dai, Lunxiao Li, Kun Zhao, Eardi Lila, Paul K. Crane, Heng Huang, Dongkuan Xu, Haoteng Tang

Computer Science Faculty Publications

With the rapid progress of large language models (LLMs), advanced multimodal large language models (MLLMs) have demonstrated impressive zero-shot capabilities on vision–language tasks. In the biomedical domain, however, even state-of-the-art MLLMs struggle with basic Medical Decision Making (MDM) tasks. We investigate this limitation using two challenging datasets: (1) three-stage Alzheimer’s disease (AD) classification (normal, mild cognitive impairment, dementia), where category differences are visually subtle, and (2) MIMICCXR chest radiograph classification with 14 non–mutually exclusive conditions. Our empirical study shows that text-only reasoning consistently outperforms vision-only or vision–text settings, with multimodal inputs often performing worse than text alone. To mitigate this, …

Redesigning Online Graduate Orientation To Foster Academic Resilience And Prevent Underperformance, Stella Michael-Makri, David E. Rodriguez

Journal of Academic Underperformance

Graduate students in fully online programs often begin their academic journey without adequate preparation for the emotional, structural, and cultural challenges of graduate-level work. For students who are first-generation, racially marginalized, international, or returning to education after time away, this lack of scaffolding can lead to early disengagement, underperformance, or attrition. Orientation, often treated as a checklist of logistical tasks, represents a missed opportunity for meaningful academic intervention. This manuscript proposes a five-module conceptual model for online graduate orientation designed to proactively support online graduate students in the domains of emotional regulation and academic identity, time management and executive functioning, …

Synthesis And Characterization Of Transition Metal Carbide (Max) And Mxene Nanoflakes For Energy Storage And [email protected], Srikanth Ragunath B Mr

Theses and Dissertations

Rapid growth in population and industrialization created a huge demand for superior energy storage devices. Thus, the researchers are in constant search of developing exotic materials towards energy harvesting and storage devices. Batteries, supercapacitors, and fuel cells received a great attention to meet the global demand for energy storage. Among them, supercapacitors are widely preferred as energy storage devices due to higher power density, longer cycle life, and fast charging. The performance of the supercapacitors highly depends on the choice of electrode materials and electrolyte.

Recently, “MXenes”  a new class of layered a new class of layered a new …

Super-Resolution Remote Sensing Datasets For Application To Caral–Supe Archeological Sites Employing Sar And Dems, Jungrack Kim, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

Publicly accessible spaceborne remote sensing datasets often lack the spatial resolution required to reliably distinguish archeological features from their surrounding geomorphological contexts. In this study, we assess the potential of super-resolution (SR) products derived from multiple public-domain remote sensing datasets for a systematic archeological survey in the Caral–Supe region. We focus on Synthetic Aperture Radar (SAR) and topographic datasets—including Sentinel-1, Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR), and Digital Elevation Models (DEMs)—because of their capacity to detect subtle surface expressions and shallow subsurface structures obscured by vegetation or sediment cover. Using state-of-the-art deep learning algorithms, …

Making The Virtual Real: Measurement-Powered Tunneling Engines, Rafael Sánchez, Alok Nath Singh, Andrew N. Jordan, Bibek Bhandari

Mathematics, Physics, and Computer Science Faculty Articles and Research

Quantum tunneling allows electrons to be transferred between two regions separated by an energetically forbidden barrier. Performing a position measurement that finds a particle in the barrier forces the tunneling electrons to transition from having a classically forbidden energy to an energy above the barrier height. We exploit this effect to define quantum tunneling engines that can use the unconditioned detection of virtually occupied states as a resource for power generation and cooling. Leveraging energy exchange with the detector, we show that the device can operate in a hybrid regime, enabling simultaneous cooling and power generation. Furthermore, we demonstrate measurement-assisted …

Rural–Urban Differences In Cognitive Outcomes Among Older Adults: The Roles Of Falls And Depressive Symptoms, Ayse Malatyali, Tom Cidav, Lisa A.K. Wiese, Jian Zou, Monique J. Brown Ph.D., Mph, Junfeng Ma, Breno S. Diniz, Ladda Thiamwong

Faculty Publications

Background: Older adults with Alzheimer’s Disease and Related Dementias (ADRD) experience a higher risk of falls. However, research lacks evidence on the effect of fall exposure on cognitive impairment and dementia. We investigated the association of falls and depressive symptoms with cognitive impairment and dementia in a nationally representative sample. Methods: We analyzed data from 6221 participants (age ≥ 65) in the Health and Retirement Study (HRS) from the 2018–2020 waves, using Multinomial logistic regression models. Measures included the HRS health status questionnaire, HRS cognition scale, and the Center for Epidemiological Studies Depression scale. Results: Prevalence of fall exposure across …

Characterizing Atmospheric Turbulence With The Lunar Step Response Method, Patrick D. Carattini, Caleb J. Stilp, Katelyn M. Atkinson, Stephen C. Cain

Faculty Publications

Most methods that astronomers use to characterize the strength of atmospheric turbulence in and around their observatories use differential image motion monitors observing a star to provide the necessary data for the measurement. With the Moon becoming a greater national priority, the need to characterize atmospheric paths between observatories on Earth and the Moon is potentially going to grow in the future. To this end, the differential image motion monitor is not an ideal instrument for characterizing turbulence along paths between observatories and the Moon as the bright Moon makes it difficult to detect and locate stars in its vicinity. …

Biogeochemical Controls On Phosphorus Transport And Legacy Storage Across A Coastal Watershed, Lee Potter

LSU Doctoral Dissertations

Excess phosphorus (P) loading is a key driver of eutrophication and harmful algal blooms (HABs) in aquatic systems worldwide. This relationship is of increasing concern in coastal Louisiana, where climate variability, altered hydrology, and land-use change converge, resulting in increased hydrologic and nutrient loading into coastal systems. This dissertation examines controls on P cycling in the Lake Pontchartrain Basin through a multi-scale framework linking estuarine processes, watershed loading, climate and weather patterns, and sediment dynamics. The dissertation begins with an overview of the study region, P dynamics, and changes in hydrology and nutrient loading patterns. Chapter 2 presents a spatial …

Rural–Urban Differences In Cognitive Outcomes Among Older Adults: The Roles Of Falls And Depressive Symptoms, Ayse Malatyali, Tom Cidav, Lisa A.K. Wiese, Jian Zou, Monique J. Brown Ph.D., Mph, Junfeng Ma, Breno S. Diniz, Ladda Thiamwong

Faculty Publications

Background: Older adults with Alzheimer’s Disease and Related Dementias (ADRD) experience a higher risk of falls. However, research lacks evidence on the effect of fall exposure on cognitive impairment and dementia. We investigated the association of falls and depressive symptoms with cognitive impairment and dementia in a nationally representative sample. Methods: We analyzed data from 6221 participants (age ≥ 65) in the Health and Retirement Study (HRS) from the 2018–2020 waves, using Multinomial logistic regression models. Measures included the HRS health status questionnaire, HRS cognition scale, and the Center for Epidemiological Studies Depression scale. Results: Prevalence of fall exposure across …

Re: Conditional Approval Letter With Comments For The Draft Final 2026 Residential Metals Abatement Program (Rmap) Anselmo Mine Yard Development Plan (Dated February 25, 2026), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Measuring What Matters: Specifications Grading And Latin* Students’ Mathematics Identity, Luis Miguel Fernández, Mayra Ortiz Galarza, Cristina Villalobos, Martha Asare

School of Mathematical & Statistical Sciences Faculty Publications

This study examined Specifications Grading, an alternative grading system emphasizing clearly defined learning outcomes and revision, and mathematics identity among 846 Latin* Calculus I students at a Hispanic-Serving Institution. Mathematics identity, comprising competence/performance, recognition, and interest, was measured at the beginning and end of the semester. Repeated-measures analyses indicated stable competence/performance and recognition alongside declines in interest. Specifications Grading was associated with increased mathematics identity, and multilingual students experienced smaller declines than their peers overall.

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Este estudio examinó la calificación por especificaciones, un sistema de evaluación alternativo que enfatiza resultados de aprendizaje claramente definidos y oportunidades estructuradas de revisión, …

Opportunities, Challenges, And Conspicuous Absences: An Integrative Review Of The Social Work Literature On Artificial Intelligence, Michael J. Massey, Ian G. Williams, Grace C. Polistina, Eathan A. Breaux

Publications and Research

INTRODUCTION: Social work discourse regarding artificial intelligence (AI) in practice, research, and education has proliferated over the last 5 years, reflecting both excitement over its potential and ambivalence about its ethical challenges. However, the extent to which social work is fully engaging with the structure of AI and its enormous impacts on the environment, labour, and distribution of power remains unclear.

METHODS: An integrative review of social work literature from 2020–2024 was conducted to address two research questions: 1) What is the nature of the social work discourse related to AI? 2) To what extent is the discourse …

Heat And Socioeconomic Deprivation Compound To Drive Coronary Heart Disease In Los Angeles, Shutong Huo, Tessa R. Pulido, Reginald S. Archer, Joshua B. Fisher, Jason A. Douglas

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background:

Socioeconomic deprivation and environmental heat exposure each increase cardiovascular risk, yet evidence is limited on how these stressors co-occur and jointly shape disease burden within cities. Mapping their overlap can inform equity-oriented planning and needs-based allocation of health and social protection resources.

Methods:

We conducted an ecological geospatial analysis of 2,513 census tracts in Los Angeles County. Adult coronary heart disease (CHD) prevalence was obtained from CDC Population Level Analysis and Community Estimates (2021). Socioeconomic deprivation was measured using the Social Deprivation Index (SDI), and heatwave surface heat hazard was measured using land surface temperature (LST) retrieved from the …

Nonstationary Flood Frequency Analysis For Urban Watersheds Using Open-Source Bayesian Software: Contrasting Case Studies From Texas, C. Haden Smith, Brian Skahill, David A. Margo

Mathematics and Statistics Faculty Publications and Presentations

Urban flood frequency analysis faces unique challenges as land development alters watershed hydrology, producing nonstationary flood records. This study demonstrates nonstationary flood frequency analysis (NSFFA) using RMC-BestFit, an open-source Bayesian software, through two Texas case studies. Brays Bayou at Houston (96 years of record) exemplifies an urbanized watershed with increasing flood trends; a step-logistic model captures both the abrupt increase in mean flood magnitude around 1968 and the progressive decrease in log-space variance as urbanization homogenized runoff response. O.C. Fisher Reservoir (169 years of record) exhibits decreasing trends attributed to brush encroachment and groundwater extraction; despite a sinusoidal model achieving …