A Two-Stage Changepoint-Copula Framework For Non-Stationary Count Time Series: Application To Tropical Cyclones,
2026
Old Dominion University
A Two-Stage Changepoint-Copula Framework For Non-Stationary Count Time Series: Application To Tropical Cyclones, Md Iqbal Hossain, Norou Diawara
Mathematics & Statistics Faculty Publications
Cross-basin tropical cyclone variability may exhibit complex, non-linear dependence structures influenced by large-scale climate modes and potential regime shifts. Reliance on traditional linear correlation measures without accounting for structural changes can therefore lead to misleading interpretations of global storm relationships. This study investigates the regional dependence structures of tropical cyclone counts across six major ocean basins (NA, ENP, WNP, NI, SI, and SP) from 1980 to 2024. We adopt a two-stage analytical framework integrating changepoint detection and copula modeling to address non-stationarity in both marginal distributions and dependence structures. First, we identify a significant structural break in the year 2000 …
A Quantitative Analysis Of Burrowing And Subterranean Locomotion In The Sand Lance Using A Transparent Sediment,
2026
Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido, Japan
A Quantitative Analysis Of Burrowing And Subterranean Locomotion In The Sand Lance Using A Transparent Sediment, Issei Fujita, Makoto Tomiyasu, Jun Yamamoto, Yasuzumi Fujimori
Journal of Marine Science and Technology–Taiwan
Sand lances (Ammodytes spp.) rely on rapid burrowing into sediment for predator avoidance. Although their sediment grain-size preferences are well documented, the biomechanics underlying burrowing success remain unclear because natural substrates are opaque. Using a transparent-sediment system, we directly visualized and quantified burrowing kinematics to: (1) test the effect of body size (total length, TL) on burrowing success; (2) examine entry mechanisms (e.g., swimming speed, entry angle); and (3) describe locomotion within sediment. Logistic regression on the full dataset (N = 28 fish) identified TL as the primary determinant of success, with larger individuals exhibiting significantly higher success …
Cruise Network Design Under Sequential Duopolistic Entry,
2026
Department of Logistics Management, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
Cruise Network Design Under Sequential Duopolistic Entry, Ta-Hui Yang, Ching-Hui Tang, Wan-Tien O
Journal of Marine Science and Technology–Taiwan
This study addresses the network design for international cruise services in a duopolistic market, where carriers enter and make decisions sequentially. The leader, who makes the first move, makes decisions as there is no competitor in the market. The follower, who makes decisions later, has to design their network considering the existing leader’s network. The leader’s model is a mixed integer linear problem while the follower’s model is a mixed integer nonlinear problem. Therefore, a heuristic is proposed to solve the problem. The commercially available general algebraic modeling system is used in conjunction with its different solvers to solve the …
Effect Of Heat Treatment On The Corrosion And Wear Behavior Of 17-4 Ph Stainless Steel For Marine Applications,
2026
Department of Optoelectronics and Materials Technology，National Taiwan Ocean University，Keelung 202,Taiwan
Effect Of Heat Treatment On The Corrosion And Wear Behavior Of 17-4 Ph Stainless Steel For Marine Applications, Syuan Tai, I-Kon Lee, Ming-Yuan Lin, Kang-Yu Liao, Chin-Chun Chang, Hung-Bin Lee
Journal of Marine Science and Technology–Taiwan
This study explores the tribocorrosion behavior of conventionally cast 17-4 PH stainless steel under real seawater conditions, focusing on the effects of three heat treatments (Solution, H900, H1100). Electrochemical tests, tribocorrosion experiments, SEM, XPS, and quantitative analysis were used to establish a three-stage tribocorrosion mechanism. Results show that H900 exhibits superior corrosion and wear resistance, while H1100 suffers increased material loss and surface cracking at high potentials. Elemental analysis revealed NbC migration forming third-body particles, which, although briefly reducing friction, induced local stress concentration and crack initiation. The findings highlight the critical influence of microstructure, passive film stability, and third-body …
Enhancing Underwater Imagery And Organism Detection Using Reinforcement Learning,
2026
College of Engineering Guindy, Anna University, Chennai, Tamil Nadu, India
Enhancing Underwater Imagery And Organism Detection Using Reinforcement Learning, K. Arul Deepa, P. Ramya, Karpaga Vinodha, Dharmaraja C
Journal of Marine Science and Technology–Taiwan
Underwater environments pose significant challenges in assessing image quality and organism detection due to light scattering and absorption, which limits visibility and color fidelity. Existing solutions often fail to effectively address these challenges, resulting in suboptimal image quality and hindering organism identification. This paper examines the problem through a dual-focused approach: enhancing underwater images and detecting organisms using the Underwater Image Enhancement Benchmark (UIEB) dataset. The first step introduces a state-of-the-art method for image enhancement by applying reinforcement learning (RL) principles. By formulating the enhancement process as a Markov Decision Process (MDP)—where states are represented by image features and actions …
Climate Change Impacts On Hydrology In The Upper James Watershed,
2026
Old Dominion University
Climate Change Impacts On Hydrology In The Upper James Watershed, Imiya Mudiyanselage Chathuranika, Dalya Ismael
Engineering Technology Faculty Publications
Hydrological modeling of the Upper James Watershed (UJW), Virginia, is critical for predicting water availability, flood management, agriculture, ecosystem protection, and hydropower production under increasing climate change. The Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) is applied to evaluate climate change impacts on key hydrological components within the watershed. Future climate conditions were assessed for the near (NF: 2026-2050), mid (MF: 2051-2075), and far (FF: 2076-2100) periods using three Global Climate Models (GCMs) under Shared Socioeconomic Pathways SSP 2-4.5 and SSP 5-8.5. Climate data were bias-corrected using the Linear Scaling Method (LSM) and used to drive the HEC-HMS model. Results project …
Assessing Climate Change Impacts On Wildfire Risk In Central Appalachian Forests Of The Eastern United States,
2026
Old Dominion University
Assessing Climate Change Impacts On Wildfire Risk In Central Appalachian Forests Of The Eastern United States, Imiya Mudiyanselage Chathuranika, Dalya Ismael
Engineering Technology Faculty Publications
Wildfire risk is increasing in the eastern U.S., yet spatial and climate-driven assessments remain limited. This study evaluates climate change impacts on wildfire risk in the Upper James Watershed (UJW) using baseline (2000–2019), near-future (2021–2040), and far-future (2061–2080) projections from a 12-model CMIP6 global climate model (GCM) ensemble under SSP2–4.5 and SSP5–8.5. A wildfire risk model was developed in ArcGIS Pro using nine key factors and validated with MODIS hotspot data, showing good agreement between modeled risk patterns and observed fire occurrences (NOF = 0.21, RMSE = 4.20, MAE = 3.37). Baseline risk was primarily driven by land cover, fire-lookout …
Historical Changes In The Seasonality And Variability Of Daily Surface Air Temperature In Era5 And Cmip6 Models,
2026
University at Albany, State University of New York
Historical Changes In The Seasonality And Variability Of Daily Surface Air Temperature In Era5 And Cmip6 Models, Zirui Wan
Electronic Theses & Dissertations (2024 - present)
This thesis investigates historical changes in the seasonality and daily variability of near-surface air temperature (Tas) during 1950–2024 using ERA5 reanalysis and simulations from 21 CMIP6 models. ERA5 and CMIP6 show broadly similar climatological structures of the Tas seasonal cycle and variability, with considerable inter-model discrepancies. Both ERA5 and CMIP6 show decreasing Tas variability over northern mid-high latitudes, while Tas variability increases in the low latitudes in ERA5 but changes little in CMIP6 multi-model mean (MMM) due to different change patterns among the models. To investigate the mechanisms of historical Tas variability changes, I analyzed the relationships between Tas variability …
An Evaluation Of Current And Future Extreme Precipitation Events In The South American Altiplano Using Convective-Permitting Model Simulations,
2026
University at Albany, State University of New York
An Evaluation Of Current And Future Extreme Precipitation Events In The South American Altiplano Using Convective-Permitting Model Simulations, Karen R. Conron Chamberlain
Electronic Theses & Dissertations (2024 - present)
Extreme precipitation events in the South American Altiplano present significant hazards to communities in the Andean region, yet their future characteristics under anthropogenic climate change remain uncertain because of complex terrain and limitations of course-resolution climate models. This study evaluates the ability of South America Affinity Group Weather Research and Forecasting (SAAG-WRF) model with 4-km grid-spacing to reproduce 2000-2015 temperature, precipitation, and extreme precipitation events over the Altiplano. Examination of projected future changes is completed using the SAAG-WRF pseudo global warming (WRF PGW) simulation representing an approximately 3°C warmer global climate. The historical/control simulation (WRF CTL) was evaluated against DECADE …
Key Processes Involved In The Vortex Alignment Of Sheared Tropical Cyclones,
2026
University at Albany, State University of New York
Key Processes Involved In The Vortex Alignment Of Sheared Tropical Cyclones, Luis O. Hernandez
Electronic Theses & Dissertations (2024 - present)
Tropical cyclones (TCs) are challenging to forecast when under vertical wind shear (VWS). VWS tilts a TC’s vortex, creating asymmetries in its structure that impedes intensification. Although work has been done to conceptualize and understand how TCs evolve under shear and how they axisymmetrize and intensify, vortex alignment remains a complex and unresolved topic. The goal of this study is to assess what physical processes are important to tilt reduction and how these processes evolve in weak TCs. Using the Hurricane Analysis Forecast System Model-B (HAFS-B) 2.1, a case study on two storms, Hurricane Earl (2022) and Hurricane Lee (2023) …
Drivers Of Extreme Streamflow During A Snowmelt-Enhanced Heavy Rainfall And Atmospheric River Event In The Catskill Mountains Of New York,
2026
University at Albany, State University of New York
Drivers Of Extreme Streamflow During A Snowmelt-Enhanced Heavy Rainfall And Atmospheric River Event In The Catskill Mountains Of New York, Christopher A. Gilberti
Electronic Theses & Dissertations (2024 - present)
This study uses atmospheric reanalysis, precipitation and snow water equivalent (SWE) analyses, mesonet observations, and streamflow records to examine the impact of an atmospheric river storm that produced heavy rainfall and snowpack ablation across the Catskill Mountains of New York on 24–25 December 2020. Earlier in December, an antecedent storm produced SWE values in the Catskills above the 90th percentile for that point in the season. The atmospheric river event followed with strong southerly warm-air advection ahead of an anomalously deep trough, temperatures and dewpoints that exceeded 10°C, and heavy orographically enhanced rainfall and rapid snowmelt. Sensible heat fluxes …
The Impact Of Downdraft Ventilation On Tropical Cyclone Intensity And Structure Using Aerial Reconnaissance Observations,
2026
University at Albany, State University of New York
The Impact Of Downdraft Ventilation On Tropical Cyclone Intensity And Structure Using Aerial Reconnaissance Observations, Nicholas E. Johnson
Electronic Theses & Dissertations (2024 - present)
Tropical cyclone (TC) intensity can be challenging to predict since it is modulated by many physical processes. One of these processes is ventilation: the injection of relatively cool, dry environmental air into the warm core of a TC that acts as “anti-fuel”, inhibiting intensification and increasing uncertainty with intensity forecasts. While ventilation has been examined in numerical modeling studies, there have been a limited number of observational studies investigating ventilation. The two primary objectives of this dissertation are to develop methods for measuring downdraft ventilation from aerial reconnaissance observations and to use those observations to better understand how ventilation affects …
On The City-Scale Energy Balance Under Electrification And Renewable Generation: The New York City Case,
2026
University at Albany, State University of New York
On The City-Scale Energy Balance Under Electrification And Renewable Generation: The New York City Case, Nour Elgalad
Electronic Theses & Dissertations (2024 - present)
Integration of renewable resources to meet the growing energy demand of dense urban regions is becoming a global priority under decarbonization mandates. This study contributes to these ongoing efforts by assessing the feasibility of using locally deployable urban renewable resources, namely offshore wind in the New York Bight region and rooftop photovoltaic (PV) systems over New York City, to meet the electricity demand of the city, and the grid vulnerabilities that emerge, during two contrasting extreme-weather periods: the intense heatwave of June 2025 and a fully electrified winter cold snap in January 2018. A unified, meteorologically driven modelling framework, based …
Analysis Of Δ¹¹B As A Seawater Ph Proxy: Comparing Ocean Circulation Inverse Model Output With Marine Calcifier Geochemistry,
2026
Claremont McKenna College
Analysis Of Δ¹¹B As A Seawater Ph Proxy: Comparing Ocean Circulation Inverse Model Output With Marine Calcifier Geochemistry, Jesse I. Dong
CMC Senior Theses
Increasing anthropogenic carbon flux into the oceans decreases seawater pH, alters dissolved inorganic carbon speciation, and reduces biogenic calcification. The marine calcifiers— specifically corals and coralline algae—incorporate elements from surrounding seawater into their carbonate structures, which preserve past records of ocean carbon chemistry. In particular, boron in biogenic carbonate is a potentially valuable proxy for historical ocean pH across human timescales. Within seawater, boron primarily exists as boric acid B(OH)3 and borate ions B(OH)4 - , where higher pH favors the formation of borate ions. Borate ions preferentially incorporate the heavier ¹¹B isotope over 10B. On the other hand, if …
Changepoint Analyses Confirms Global Tropical Cyclone Frequency Decline,
2026
Lawrence Berkeley National Laboratory
Changepoint Analyses Confirms Global Tropical Cyclone Frequency Decline, Michael Wehner, Thomas Fisher, Norou Diawara, Robert Lund
Mathematics & Statistics Faculty Publications
Changes in tropical cyclone frequencies as the climate warms is a topic of significant current debate [1, 2]. There is no accepted theory of how tropical cyclogenesis might respond to a warmer ocean-atmosphere system as multiple controlling factors exist [3–7]. Anthropogenic warming of surface ocean temperatures due to increased greenhouse gas concentrations [8] increases the potential for tropical cyclogenesis [9–11]; however, realized cyclogenesis also requires an initial local disturbance [12–16] to develop. Most multi-decadal tropical cyclone permitting climate models (i.e. resolutions of 15-50km) exhibit frequency decreases in warmer climates, despite the increase in tropical cyclogenesis potential [17–25]. In this paper, …
A Composite Narxnn Approach To Photovoltaic Power Forecasting With Integrated Weather Inputs And Uncertainty Quantification,
2026
University of Texas at El Paso
A Composite Narxnn Approach To Photovoltaic Power Forecasting With Integrated Weather Inputs And Uncertainty Quantification, Denisse Urenda Castañeda, Sharmin Abdullah, Jackson Morgan, Honglun Xu, Michael Pokojovy, Tzu-Liang Tseng
Mathematics & Statistics Faculty Publications
Solar photovoltaics (PV) are a major source of sustainable energy. Yet, their power output is highly sensitive to environmental variability, particularly solar irradiance, cloud cover, wind, and temperature. Accurate forecasting of PV power is essential for efficient grid integration and energy planning, especially in applications requiring reliable longer-term forecasting rather than one-step-ahead predictions. This study presents a PV power forecasting approach using Nonlinear Autoregressive models with Exogenous Inputs (NARX), integrating large-scale numerical weather historical data as exogenous variables. Although NARX models effectively capture temporal dependencies, they can become overly dependent on historical power values, reducing responsiveness to real-time weather changes. …
A Geospatial Assessment Of Groundwater Salinization In A Multi-Aquifer System: Durango, Mexico,
2026
Missouri State University
A Geospatial Assessment Of Groundwater Salinization In A Multi-Aquifer System: Durango, Mexico, Juan Lopez-Sierra
Graduate Theses/Dissertations
Groundwater salinization poses a critical environmental concern for water resource sustainability in arid and semi-arid regions. This study evaluates spatial and temporal patterns of groundwater salinity across the state of Durango, Mexico, using total dissolved solids (TDS), sodium adsorption ratio (SAR), as salinity indicators and nitrate-nitrogen (NO₃–N) as an anthropogenic indicator. Groundwater quality data were obtained from (CONAGUA), a Mexican water agency. To assess salinity variations with respect to time, while minimizing interannual sampling bias, two multi-year sampling periods were selected: 2012-2013, and 2020-2021. Final datasets consisted of 122 wells for 2012–2013 and 131 wells for 2020–2021. The wells were …
Linking Boundary Type, Storm Mode, And Tornado Intensity In Illinois,
2026
Parkland College
Linking Boundary Type, Storm Mode, And Tornado Intensity In Illinois, Jakob Barton
A with Honors Projects
A large dataset of tornadoes across Illinois from 2007-2024 were analyzed for different characteristics of thunderstorms and tornadoes, these characteristics were then compared with each other to find correlation and trends.
Sedimentological And Geochemical Investigation Of The Origin Of Upper Pennsylvanian Black Shales, East-Central Appalachian Basin,
2026
West Virginia University
Sedimentological And Geochemical Investigation Of The Origin Of Upper Pennsylvanian Black Shales, East-Central Appalachian Basin, Tyler Hickey
Graduate Theses, Dissertations, and Problem Reports (ETD)
In the east-central Allegheny foreland basin, laminated black shales overlying Upper Pennsylvanian Glenshaw Fm. coal seams record paleoenvironmental conditions associated with the termination of peat swamp deposition before, during, and after the Carboniferous Coal Forest Collapse (CCFC), a major paleobotanical evolutionary event during the Late Paleozoic Ice Age (LPIA) that contributed to extinction of lepidodendrons near the Desmoinesian-Missourian boundary (~306 Ma). Previous investigations of the CCFC commonly implicate an episode of aridification during intensification of LPIA glaciation that stressed the lepidodendrons beyond their ecological tipping point; however, the cause of this aridification is unclear. An investigation of Glenshaw Fm. black …
Quantum Mechanics As A Framework For Data Assimilation And Its Application To Atmospheric Parameterization,
2026
Dartmouth College
Quantum Mechanics As A Framework For Data Assimilation And Its Application To Atmospheric Parameterization, David Freeman
Dartmouth College Ph.D Dissertations
Quantum mechanics, as a mathematical system, can be understood as a generalization of classical probability theory. Quantum Mechanical Data Assimilation (QMDA) is a method in which classical dynamical systems are embedded into a quantum mechanical setting, with an associated data assimilation scheme leveraging the operator algebraic setting. In this dissertation, the algebraic structure underlying the operator theoretic formulation of QMDA is discussed. A procedure for closure of dynamical systems based on QMDA, known as Quantum Mechanical Closure (QMCl), is then constructed, and the procedures for constructing the quantum embeddings and implementing QMCl in practice are laid out and implemented for …
