Physical Sciences and Mathematics Commons^™

Climate-Driven Degradation And Lifecycle Reliability Of Building-Integrated Photovoltaic Systems: Integration Challenges And Deployment Pathways, Mohammad Nur-E-Alam, Mohammad Khairul Basher, Mohammad Tariqul Islam, Mongi Amami, Rajesh Haldhar, M. Khalid Hossain

Research outputs 2022 to 2026

Building-integrated photovoltaics (BIPV) are becoming a more popular source of renewable energy. It is an on-site renewable energy source within buildings but has limited growth due mainly to lifespan issues throughout the entire life cycle from manufacturing to design, installation, electrical integration, operation, and end of life. This paper reviews the climate-driven deterioration mechanisms of BIPV, including thermal cycling, moisture ingress, atmospheric pollutants, wind loads, etc. They relate these climate-driven deterioration mechanisms to BIPV performance deterioration, energy yield reductions, safety concerns related to energy loss, and long-term reliability of BIPV systems across all parts of the BIPV life cycle. Through …

Sentinel: Evaluating Occlusion-Centered Next-Best-View Selection Using Rgb-Derived Pseudo-Geometry, Paul Nassar

Master's Theses

Three-dimensional cameras provide direct geometric measurements, but their cost, weight, power requirements, and calibration constraints can limit their use in various lightweight or large-scale sensing systems. A potential alternative is to use conventional two-dimensional RGB cameras together with geometric reconstruction models that infer a partial three-dimensional representation from images. This thesis evaluates that possibility for next-best-view (NBV) selection through Sentinel, an occlusion-centered system for static, object-centric scenes with known camera poses and intrinsics. Sentinel converts source RGB observations into pseudo-geometry using monocular depth or point-map predictions, combines those predictions with camera-ray evidence, identifies occluded unknown regions, and selects a candidate …

Predicting Student Belonging In Computing Education: A Multimodal Machine Learning Approach Using Eeg And Survey Data, Hannah Moshtaghi

Master's Theses

Measuring students’ sense of belonging, characterized by feelings of acceptance, inclusion, and encouragement from teachers, remains a significant challenge in computing education. Prior research has associated this multidimensional construct with positive academic outcomes and has identified instructors’ growth- and fixed-mindset messaging as a potential influence. However, belonging is a complex and deeply personal experience that is difficult to capture through direct observation alone. Current measurement methods rely on self-report surveys, which may not capture every aspect of an experience that can also involve emotional and cognitive responses.

This thesis investigates whether combining EEG data recorded during a belonging questionnaire with …

Synthesis And Characterization Of Carbon Quantum Dots And Gold Nanoparticles For Norovirus Biosensing Applications In Water Systems, Breanne Evans

Master's Theses

Rapid, reliable detection of viral pathogens remains a significant challenge across water-treatment and environmental monitoring systems, including drinking-water, wastewater, water reuse, and environmental surveillance applications. Waterborne viral contamination can pose substantial public-health risks, making early detection essential for protecting water quality and responding quickly to treatment failures or contamination events. Direct potable reuse (DPR) is one particularly demanding example because it requires continuous verification of treatment performance and the broader need for rapid virus monitoring extends across many water-treatment and environmental surveillance applications. Norovirus is a priority target because of its widespread occurrence in wastewater, environmental persistence, and exceptionally low …

Bayesian Variable Selection In High-Dimensional Ordinal Quantile Regression Models, Mai Dao, Md. Sakhawat Hossain, Zhuanzhuan Ma

School of Mathematical & Statistical Sciences Faculty Publications

Quantile regression (QR) provides a flexible statistical framework for modeling the entire conditional distribution of the response variable, making it useful for analysis in various fields. Despite its advantages, existing methods for QR often encounter numerical challenges in high-dimensional settings, especially for those with ordinal responses. In this paper, we use a latent-response framework to construct a Bayesian hierarchical model to conduct parameter estimation and variable selection for ordinal QR. Using the asymmetric Laplace working likelihood and the horseshoe prior for the regression coefficients, we obtain the posterior samples to be screened by the sequential two-means clustering process to identify …

Positive Curvature And Discrete Abelian Symmetry, Lee Kennard, Elahe Khalili Samani, Catherine Searle

Mathematics

By replacing the torus with an elementary abelian two-group, we generalize Grove and Searle’s maximal symmetry result and Wilking’s half-maximal symmetry result for positively curved manifolds with an isometric torus action. © The Author(s) 2026.

Crystal Structure Of New Polar Rare Earth Borates Na2.62Ln2.12(Bo3)3 (Ln = Pr, Nd, Sm) Containing Isolated Bo3 Groups, Alevtina A. Maksimova, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

Three new rare earth borates, Na2.62Ln2.12(BO3)3 (Ln = Pr, Nd, Sm), were synthesized via a high-temperature solution reaction using a BaCO3–H3BO3–NaF flux and structurally characterized by single-crystal X-ray diffraction analysis. The compounds crystallize in the orthorhombic space group Amm2 with lattice parameters a = 5.0985(10) Å, b = 11.180(2) Å, c = 7.1483(14) Å, and a unit cell volume of 407.48(14) ų (Z = 2) for Na2.62Pr2.12(BO3)3, a = 5.0983(10) Å, b = 11.181(2) Å, c = 7.1491(14) Å, and a unit cell volume of 407.51(14) ų (Z = 2) for Na2.62Nd2.12(BO3)3, and a = 5.08630(10) Å, b …

A Stabilized Weighted Interior Penalty Method For Thermal Convection Model In Heterogeneous Porous Media, Yuanyuan Hou, Qianqian Ding, Xiaoming He, Yanping Lin

Mathematics and Statistics Faculty Research & Creative Works

In this article, we propose and analyze a stabilized weighted interior penalty method for solving the thermal convection problems in heterogeneous porous media. We first transform the thermal convection model into the pressure primal form with homogeneous Neumann boundary condition and develop a symmetric weighted interior penalty method to handle the discontinuous Darcy number and automatically adjust the penalty coefficient corresponding to the varying permeability. Then we recover the velocity by a stabilized method and incorporate it into the energy equation to obtain the temperature. The stability and convergence rates of the numerical solutions are rigorously proved and verified by …

Single Crystal Growth Of The Orthoborate Nabalu(Bo3)2 And Optical Investigation Of Eu3+ And Tb3+ Doped Nabalu(Bo3)2, Alevtina A. Maksimova, Mark D. Smith, Lakshani W. Masachchi, Hans Conrad Zur Loye

Faculty Publications

Sodium barium lutetium borate NaBaLu(BO₃)₂ crystals were synthesized using a high-temperature solution method. The crystal structure of this layered orthoborate is described and corresponds to that of an extensive orthoborates family, NaBaR(BO₃)₂ (R = Sc, Y, Yb, Tb – Lu). NaBaLu(BO₃)₂ was doped by Eu³⁺ and Tb³⁺ to explore its performance as a host material and to investigate the luminescent properties of the Eu³⁺ and Tb³⁺ doped materials. The emission spectra of the NaBaLu(BO₃)₂:Ln (Ln = Eu, Tb) crystals are presented. The most …

Criticality In A Heterogeneous Neutron Transport Rod Model, Samuel Kaleb Crowford

All Graduate Reports and Creative Projects, Fall 2023 to Present

This work studies the stochastic behavior of neutron populations in a one-dimensional rod model using Monte Carlo simulation. The first part of this project reproduces the computational results of Dumonteil, Horton, Kyprianou, and Zoia (2025) by independently implementing the Monte Carlo algorithm described in their article, with the asymptotic behavior of the first moment analyzed in relation to the dominant eigenvalue and adjoint eigenfunction of the neutron transport operator. The model is then extended to a heterogeneous setting by introducing a central region where fission is suppressed. A global expectation over initial positions and directions is used to estimate the …

Temperature And Salinity Effects On The Physiology Of Bullfrog Tadpoles (Lithobates Catesbeianus) From A Suburban Temperate Wetland, Angela Brown

Theses, Dissertations and Culminating Projects

One of the most robust amphibians is the American Bullfrog, Lithobates catesbeianus, which is a widespread species that is invasive worldwide, and is broadly tolerant of a range of environmental conditions. Despite this tolerance, survival and performance of adult L. catesbeianus can be negatively affected by increasing temperatures and salinity resulting from anthropogenic impacts, such as climate change and road salts. This study focuses on the effects of acute salinity exposure (mimicking road salt influx into a pond) on L. catesbeianus tadpoles at different larval stages. Increased salinity was predicted to negatively affect two physiological performance measures. Critical maximum temperature …

Graph Perturbation Analysis For Subgraph Counting, Hanhua Xiao, Yuchen Li, Kyriakos Mouratidis

PhD Student’s Publications Collection

Subgraph counting, which involves determining the frequency of a query graph within a data graph, has numerous applications such as query optimization, fraud detection, and evaluating the expressiveness of graph neural networks. Despite its importance, there has been no systematic study on the impact of adversarial graph perturbations on subgraph counts. In this work, we examine the kSub problem, which aims to identify k edge additions that maximize the count of a query graph. We prove that kSub is intractable due to its NP-hardness, even for constant approximation. To address this, we relax the problem into a top-k selection, termed …

Magnetic Properties And Ultrafast Spin Dynamics In Quantum Materials, Trung Kien Mac

All Graduate Theses and Dissertations, Fall 2023 to Present

Modern electronics mostly work by moving electric charge, which generates heat and hence wastes energy, especially as devices become smaller and faster. An alternative is to use the spin of electrons (a tiny magnetic property) and related “valley” states in certain atomically thin materials to store and process information more efficiently. This thesis explores how magnetism and spin behavior can be created and measured in a family of ultra-thin materials known as van der Waals quantum materials. Three kinds of materials are studied. First, atomically thin semiconductors are shaped into narrow nanoribbons. Because of their narrow size, their edges can …

A Social-Ecological Systems Approach To Integrating Outdoor Recreation And Black Bear Management: A Michigan Case Study, Megan Dorothy Stone

All Graduate Theses and Dissertations, Fall 2023 to Present

Outdoor recreation sits at the intersection of social and ecological systems, representing one of the primary ways in which humans directly interact with their natural environment. As a result, outdoor recreation management must balance providing high-quality outdoor recreation opportunities while simultaneously protecting natural resources in protected areas. Balancing these concurrent management goals has become more challenging in recent years as participation in outdoor recreation increases. This can lead to numerous negative impacts on the environment, such as wildlife disturbance. In this study, I explore the challenges and opportunities for collaboration between managers of outdoor recreation and black bears in the …

The Role Of Local Winds And A Semi-Persistent Coastal Front On The Diurnal Heat Budget In An Upwelling Bay, April P. Thibodeau, Ryan K. Walter, Piero L.F. Mazzini, Thomas P. Connolly, Christopher A. Edwards, Ian C. Robbins

Physics

Coastal embayments in nearshore upwelling systems (“upwelling bays”) play a disproportionately large role in regional oceanography. In these systems, local diurnal wind forcing and thermal gradients associated with an upwelling shadow front that forms between warmer sheltered waters inside the bay and colder recently upwelled waters outside the bay strongly influence local temperature dynamics. Despite their importance to local ecosystems, there are no long-term studies that assess the heat budget inside upwelling bays. In this study, we analyzed approximately two years of water temperature throughout the water column using an autonomous profiler in a small upwelling bay in central California …

Book Review: Radioactive Dixie: A Nuclear History Of The American South, Will Jones

Georgia Library Quarterly

No abstract provided.

Summary Report: Second Conference On Attribution Science And Climate Law, Jessica A. Wentz

Sabin Center for Climate Change Law

The Sabin Center for Climate Change Law and the Columbia Climate School hosted the Second Conference on Attribution Science and Climate Law at Columbia University on June 10–11, 2026. This event brought together an interdisciplinary group of researchers and practitioners to discuss recent developments in attribution science and the field’s relevance to climate law and policy. Participants included physical scientists, public health researchers, economists, social scientists, legal scholars, advocates, and policy experts. This report provides a written summary of the conference proceedings.

Leading The Change: Staff-Driven Ai Transformation In Smu Libraries’ Collection Team, Siew Khim Lim, Fion Goh

Research Collection Library

No abstract provided.

Emergency Risk Dispatch For Integrated Electricity-Heat Systems Under Typhoon Disasters, Tongchui Liu, Lian Tan, Dongxuan Bao, Lanting Zeng, Pengfei Hou, Ronghua Ling

Journal of System Simulation

Abstract: The spatiotemporal randomness of typhoon movement paths leads to uncertain operational risks for integrated electricity-heat systems (IEHS), making it difficult to balance system risk controllability and dispatch economy. To tackle this problem, an emergency risk dispatch (ERD) method for IEHS under typhoon disasters is proposed. An ERD model for IEHS under typhoon disasters is established within the model predictive control framework. Based on the uncertainty of typhoon wind speed prediction, a moment-based ambiguity set for uncertain equipment component failures is constructed, and a distributionally robust chance-constrained ERD model is formulated. An approximation method based on worst-case conditional value-at-risk (WC-CVaR) …

Bi-Level Coordinated Scheduling And Optimization Of Power Systems Based On Stackelberg-Gmo, Yuanxing Zhang, Jianfeng Li, Taoyong Li, Linjuan Zhang, Jincheng Liu, Bin Li

Journal of System Simulation

Abstract: , To balance the interests of the power grid and the demand side, and achieve coordinated improvements in system economic efficiency, environmental friendliness, and renewable energy accommodation capacity, this paper proposes a bi-level coordinated scheduling model based on the Stackelberg game and the GMO. A leader-follower game model incorporating carbon emission constraints and multi-scenario stochastic constraints for photovoltaic generation is constructed, with the grid operator as the leader and EVs/V2G and energy storage as the followers, resolving the core contradiction between global optimization and individual rationality. The spatio-temporal stochastic characteristics of EV travel, the cycle life of energy storage …

Energy Management Method For Integrated Energy Driven By Users’ Social Attributes, Yankai Zhu, Yujing Huang, Qinghua Wang, Xiaoning Zhang, Fang Fang, Yuguang Niu

Journal of System Simulation

Abstract: To explore a new interaction mechanism between an energy service provider (ESP) and multiple users, this paper proposes a complex modeling and energy management method for integrated energy systems driven by users' social attributes. A multi-agent interaction framework comprising an ESP and user clusters is established. To maximize the ESP's operational benefit and minimize users' energy costs, a leader-follower game-based energy management model is established within a reinforcement learning framework, and a distributed collaborative solution algorithm combining Q-learning and quadratic programming is proposed. Simulation results show that, compared with the traditional integrated demand response method, consideration of users' social …

Missing-Data-Tolerant Diffusion-Based Wind Power Scenario Forecasting Method, Yingying Shi, Xiaochong Dong, Guobin Fu, Miaomiao Ma, Yanhe Li, Xuebin Wang

Journal of System Simulation

Abstract: To address the issue of error accumulation in traditional "imputation-then-forecasting" approaches, a missing data tolerant diffusion framework (MDTDF) is proposed. An XGBoost regression model is employed to map numerical weather prediction data into deterministic power forecasts. The encoder in the denoising network extracts temporal features, which are fused with the deterministic forecasts and fed into the decoder through a cross-attention mechanism to guide the denoising process. A historical constraint mechanism is introduced to directly utilize incomplete historical data and dynamically correct the denoising result at each step through sample gradient updates and noise injection guided by historical information. The …

Optimal Scheduling Of Virtual Power Plants Considering Photothermal Power Stations And Hydrogen Energy Utilization, Yousong Chen, Ruofa Cheng, Yi Liu, Yi Zhang, Zhihao Zuo

Journal of System Simulation

Abstract: To enhance the operational stability and low-carbon performance of virtual power plants (VPPs) with high shares of renewable energy, a coordinated dispatch model integrating concentrated solar power (CSP) plants with power-to-gas (P2G) and carbon capture is developed. An optimal VPP scheduling strategy is proposed, combining a stepped carbon trading mechanism with a compensation coefficient and dynamic hydrogen blending. To address multi-source uncertainties in wind power, CSP power, and loads, an envelope boundary model is used for simulation. Information gap decision theory (IGDT) is applied to provide customized solutions for decision-makers with different risk preferences. A bi-objective optimization model is …

Time-Step Relaxation Method For Simulation With Time-Sensitive Interactions, Zhaopeng Liu, Kaidi Jin, Xunyun Liu, Dongao Zhou, Xinhai Xu

Journal of System Simulation

Abstract: In time-driven military simulation, time-step setting is a key technology for balancing operational efficiency and simulation accuracy. Based on the current research on time-step setting in military simulation, a trajectory spatiotemporal intersection calculation model is designed to address the performance bottleneck caused by the minimum time step, thus removing the constraints imposed on the minimum time step by interactions such as high-speed target detection and jamming. Experiments involving detection interaction scenarios are designed to verify the effectiveness of the model in preventing missed interactions and improving simulation efficiency.

A Review Of Spatial Indexing Technologies For Large-Scale Combat Simulation, Kaidi Jin, Xunyun Liu, Dongao Zhou, Yang Wang, Zhaopeng Liu

Journal of System Simulation

Abstract: The real-time performance and scalability of large-scale combat simulations are constrained by performance bottlenecks in spatial queries caused by massive numbers of dynamic entities. Spatial indexing technology becomes the key to solving this problem by establishing an efficient mapping between locations and entities. This paper reviews spatial indexing technologies in large-scale combat simulations. Based on an analysis of the core requirements for index structures in combat simulations, various indexing technologies along three main lines are examined: static indexing, dynamic optimization, and distributed parallelism. The principles, evolution, and applicability boundaries of these technologies are also examined, and their query and …

A Method For Assessing The Contribution Degree Of An Aviation Delivery System And Identifying Key Equipment, Xiaofeng Liu, Chengze Jiang, Xingyu Chen, Deyin Jiang, Bolin Shang, Bifeng Song

Journal of System Simulation

Abstract: Based on the delivery efficiency and delivery quality, a general aviation delivery system effectiveness evaluation model was constructed, and a calculation method of system contribution degree based on efficiency was given. By combining the system calculation experiment and simulation experiment based on agent-based modeling and simulation (ABMS), the design idea of the Monte Carlo simulation experiment for key equipment identification and equipment technology development trend analysis was sorted out, and the key equipment identification method based on ABMS and contribution evaluation was proposed. By taking the intercontinental long-range aviation delivery mission as an example, a variety of simulation experiments …

Fault-Tolerant Control Method For All-Type Actuator Faults Of Evtol Aircraft, Juan Wang, Guorui Li, Zhiyong Fan, Huijie Chen

Journal of System Simulation

Abstract: To address all-type actuator faults, especially nonlinear distortion issues, in multi-rotor eVTOL aircraft, a novel fault-tolerant control method was proposed. A fault function was established at the rotor speed level, and a fault-tolerant control algorithm combining dynamic robust nonsingular fast integral terminal sliding mode with a high-order finite-time disturbance observer was designed to achieve fault-tolerant control through rotor redundancy allocation. The nonsingular fast integral terminal sliding mode algorithm was improved, and a dynamic system containing actuator faults and their derivatives was constructed via a dynamic surface to achieve system convergence within finite time, avoiding the singularity and chattering problems …

Learning Evolution Modeling Of Multi-Cycle Nested Cloud Manufacturing Service Ecosystem, Fang Li, Deyu Zhou, Gang Wang, Guangjun Liu, Qi Hu

Journal of System Simulation

Abstract: In view of the lack of comprehensive consideration of the individual adaptability changes of enterprises caused by the collaborative governance mechanism among multiple manufacturing units and the overall evolution trend of the system in existing learning evolution models, this proposed a learning evolution model of multi-cycle nested cloud manufacturing service ecosystem. At the micro level, the adaptive linkage decision-making among multiple manufacturing units within the enterprise was achieved in the individual layer through the nesting of planning-readiness-execution-assessment (PREA) loops and OODA loops; at the macro level, the closed-loop simulation of the individual layer, organizational layer, and social layer was …

Study On Transient Electric Field Of Insulated Rail Joints In High-Speed Railway Stations Based On Dissado-Hill Model, Junli Li, Youpeng Zhang

Journal of System Simulation

Abstract: The transient electric field distribution of insulated rail joints in high-speed railway stations under lightning impulse voltages is critical to their normal operation. Under lightning impulse voltages, considering the relaxation polarization of the insulated rail joint material, a frequency-domain mathematical model of its transient electric field was established. Based on Dissado-Hill model, the measured frequency-domain dielectric spectra were fitted and analyzed to reveal the microstructural characteristics of insulated rail joints and the interaction characteristics between microscopic particles during the polarization process. The results indicate that the relative permittivity of insulated rail joints decreases with the increasing harmonic frequency of …

Intelligent Evaluation Method For Regional Air Superiority Based On Graph Convolutional Neural Network, Peng He, Yubo Tang, Jingde Liu, Yujia Tian

Journal of System Simulation

Abstract: To address the dual challenges of the lack of quantification standards and sparse air combat samples in the superiority evaluation of modern air combat, an intelligent evaluation method for regional air superiority based on a graph convolutional neural network was proposed. The spatial grid method was employed to encode the air situation of the entire battlefield airspace into a new data representation, namely the air superiority matrix. A novel air superiority quantification model was applied to quantify the air superiority label values of spatial grids, and four key operational capabilities closely related to air superiority contention were selected as …