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Articles 33091 - 33120 of 294526

Full-Text Articles in Physical Sciences and Mathematics

Consequences Of Group-Based Misperceptions Of Climate Concern For Efficacy And Action, Zoe Leviston, Tanvi Nangrani, Samantha K. Stanley, Iain Walker Jan 2024

Consequences Of Group-Based Misperceptions Of Climate Concern For Efficacy And Action, Zoe Leviston, Tanvi Nangrani, Samantha K. Stanley, Iain Walker

Research outputs 2022 to 2026

People tend to underestimate others’ environmental values, including when judging the values of minority-status groups. Using a large national sample (N = 5110), we test whether these misperceptions extend to concern about climate change in Australia, and differ depending on immigrant status, ethnicity, and where one is located (i.e., in or outside capital cities). We also examine the consequences of misperceptions for self-efficacy and pro-environmental behaviour. We find personal climate concern is high, but perceptions of others’ concern is lower. Immigrants and Australian-born participants have similarly high concern, but both groups underestimate how concerned immigrants are. Southern-Central-Asian identifiers are the …

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Multimodal Fusion For Audio-Image And Video Action Recognition, Muhammad B. Shaikh, Douglas Chai, Syed M. S. Islam, Naveed Akhtar Jan 2024

Multimodal Fusion For Audio-Image And Video Action Recognition, Muhammad B. Shaikh, Douglas Chai, Syed M. S. Islam, Naveed Akhtar

Research outputs 2022 to 2026

Multimodal Human Action Recognition (MHAR) is an important research topic in computer vision and event recognition fields. In this work, we address the problem of MHAR by developing a novel audio-image and video fusion-based deep learning framework that we call Multimodal Audio-Image and Video Action Recognizer (MAiVAR). We extract temporal information using image representations of audio signals and spatial information from video modality with the help of Convolutional Neutral Networks (CNN)-based feature extractors and fuse these features to recognize respective action classes. We apply a high-level weights assignment algorithm for improving audio-visual interaction and convergence. This proposed fusion-based framework utilizes …

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The Impact Of Environmental Policy On Renewable Energy Innovation: A Systematic Literature Review And Research Directions, Hiva Rastegar, Gabriel Eweje, Aymen Sajjad Jan 2024

The Impact Of Environmental Policy On Renewable Energy Innovation: A Systematic Literature Review And Research Directions, Hiva Rastegar, Gabriel Eweje, Aymen Sajjad

Research outputs 2022 to 2026

Renewable energy innovations are imperative to tackle the climate change crisis. However, there is a gap in the literature regarding the effectiveness of environmental policies in promoting renewable energy innovations. To bridge this gap, we have adopted a systematic literature review process covering the period from 2005 to 2023. We identified and analysed 29 articles in our final sample. Further, we employ two levels of analysis (individual-policy and policy-mix levels) for analysing the extant research. Our findings show that fiscal incentives and emissions trading policies such as the European Union (EU) Emissions Trading System (ETS) consistently promote renewable energy innovations. …

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Unleashing The Power Of Internet Of Things And Blockchain: A Comprehensive Analysis And Future Directions, Abderahman Rejeb, Karim Rejeb, Andrea Appolloni, Sandeep Jagtap, Mohammad Iranmanesh, Salem Alghamdi, Yaser Alhasawi, Yasanur Kayikci Jan 2024

Unleashing The Power Of Internet Of Things And Blockchain: A Comprehensive Analysis And Future Directions, Abderahman Rejeb, Karim Rejeb, Andrea Appolloni, Sandeep Jagtap, Mohammad Iranmanesh, Salem Alghamdi, Yaser Alhasawi, Yasanur Kayikci

Research outputs 2022 to 2026

As the fusion of the Internet of Things (IoT) and blockchain technology advances, it is increasingly shaping diverse fields. The potential of this convergence to fortify security, enhance privacy, and streamline operations has ignited considerable academic interest, resulting in an impressive body of literature. However, there is a noticeable scarcity of studies employing Latent Dirichlet Allocation (LDA) to dissect and categorize this field. This review paper endeavours to bridge this gap by meticulously analysing a dataset of 4455 journal articles drawn solely from the Scopus database, cantered around IoT and blockchain applications. Utilizing LDA, we have extracted 14 distinct topics …

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Spatially-Aware Speaker For Vision-And-Language Navigation Instruction Generation, Muraleekrishna Gopinathan, Martin Masek, Jumana Abu-Khalaf, David Suter Jan 2024

Spatially-Aware Speaker For Vision-And-Language Navigation Instruction Generation, Muraleekrishna Gopinathan, Martin Masek, Jumana Abu-Khalaf, David Suter

Research outputs 2022 to 2026

Embodied AI aims to develop robots that can understand and execute human language instructions, as well as communicate in natural languages. On this front, we study the task of generating highly detailed navigational instructions for the embodied robots to follow. Although recent studies have demonstrated significant leaps in the generation of step-by-step instructions from sequences of images, the generated instructions lack variety in terms of their referral to objects and landmarks. Existing speaker models learn strategies to evade the evaluation metrics and obtain higher scores even for low-quality sentences. In this work, we propose SAS (Spatially-Aware Speaker), an instruction generator …

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Global Meta-Analysis Of Demersal Fishing Impacts On Organic Carbon And Associated Biogeochemistry, Justin Tiano, Emil De Borger, Sarah Paradis, Clare Bradshaw, Claudia Morys, Antonio Pusceddu, Claudia Ennas, Karline Soetaert, Pere Puig, Pere Masqué, Marija Sciberras Jan 2024

Global Meta-Analysis Of Demersal Fishing Impacts On Organic Carbon And Associated Biogeochemistry, Justin Tiano, Emil De Borger, Sarah Paradis, Clare Bradshaw, Claudia Morys, Antonio Pusceddu, Claudia Ennas, Karline Soetaert, Pere Puig, Pere Masqué, Marija Sciberras

Research outputs 2022 to 2026

The potential threat of fisheries on seabed carbon is a topic of growing concern, yet existing literature presents inconsistencies leaving experts divided on the topic. We conducted a global meta-analysis to synthesize the current knowledge and quantify how demersal fishing impacts various biogeochemical properties. Direct impact studies revealed overall reductions in chlorophyll-a (Chl-a, 17%), phaeopigments (24%), and proteins (32%). Effects on these reactive compounds were more pronounced on surface sediment (0–2 cm), where the impact on total organic carbon (TOC) also became significant, demonstrating the effect of gear penetration, and highlighting that sampling strategies combining sediment layers can mask observed …

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Infrared Ship Segmentation Based On Weakly-Supervised And Semi-Supervised Learning, Isa Ali Ibrahim, Abdallah Namoun, Sami Ullah, Hisham Alasmary, Muhammad Waqas, Iftekhar Ahmad Jan 2024

Infrared Ship Segmentation Based On Weakly-Supervised And Semi-Supervised Learning, Isa Ali Ibrahim, Abdallah Namoun, Sami Ullah, Hisham Alasmary, Muhammad Waqas, Iftekhar Ahmad

Research outputs 2022 to 2026

Existing fully-supervised semantic segmentation methods have achieved good performance. However, they all rely on high-quality pixel-level labels. To minimize the annotation costs, weakly-supervised methods or semi-supervised methods are proposed. When such methods are applied to the infrared ship image segmentation, inaccurate object localization occurs, leading to poor segmentation results. In this paper, we propose an infrared ship segmentation (ISS) method based on weakly-supervised and semi-supervised learning, aiming to improve the performance of ISS by combining the advantages of two learning methods. It uses only image-level labels and a minimal number of pixel-level labels to segment different classes of infrared ships. …

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Understanding How Indigenous Knowledge Contributes To Climate Change Adaptation And Resilience: A Systematic Literature Review, Tashi Dorji, Kinley Rinchen, Angus Morrison-Saunders, David Blake, Vicki Banham, Sonam Pelden Jan 2024

Understanding How Indigenous Knowledge Contributes To Climate Change Adaptation And Resilience: A Systematic Literature Review, Tashi Dorji, Kinley Rinchen, Angus Morrison-Saunders, David Blake, Vicki Banham, Sonam Pelden

Research outputs 2022 to 2026

Climate change is one of the biggest challenges facing the world today threatening societies and the future of the planet. The impacts of climate change are more severe in poor and marginalised populations like Indigenous communities where people rely heavily on their Indigenous Knowledge (IK) to adapt to the changing environment. Climate change adaptation and resilience are critical for the survival of Indigenous communities under the threat of climate change. This systematic literature review seeks to understand how IK contributes to climate change adaptation and resilience. A total of 71 papers from Scopus were analysed using the Preferred Reporting Items …

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Irs-Enabled Noma Communication Systems: A Network Architecture Primer With Future Trends And Challenges, Haleema Sadia, Ahmad Kamal Hassan, Ziaul Haq Abbas, Ghulam Abbas, Muhammad Waqas, Zhu Han Jan 2024

Irs-Enabled Noma Communication Systems: A Network Architecture Primer With Future Trends And Challenges, Haleema Sadia, Ahmad Kamal Hassan, Ziaul Haq Abbas, Ghulam Abbas, Muhammad Waqas, Zhu Han

Research outputs 2022 to 2026

Non-Orthogonal Multiple Access (NOMA) has already proven to be an effective multiple access scheme for 5th Generation (5G) wireless networks. It provides improved performance in terms of system throughput, spectral efficiency, fairness, and energy efficiency (EE). However, in conventional NOMA networks, performance degradation still exists because of the stochastic behavior of wireless channels. To combat this challenge, the concept of Intelligent Reflecting Surface (IRS) has risen to prominence as a low-cost intelligent solution for Beyond 5G (B5G) networks. In this paper, a modeling primer based on the integration of these two cutting-edge technologies, i.e., IRS and NOMA, for B5G wireless …

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Ai-Analyst: An Ai-Assisted Sdlc Analysis Framework For Business Cost Optimization, Nuruzzaman Faruqui, Priyabrata Thatoi, Rohit Choudhary, Ivana Roncevic, Hamed Alqahtani, Iqbal H. Sarker, Shapla Khanam Jan 2024

Ai-Analyst: An Ai-Assisted Sdlc Analysis Framework For Business Cost Optimization, Nuruzzaman Faruqui, Priyabrata Thatoi, Rohit Choudhary, Ivana Roncevic, Hamed Alqahtani, Iqbal H. Sarker, Shapla Khanam

Research outputs 2022 to 2026

Managing the System Development Lifecycle (SDLC) is a complex task because of its involvement in coordinating diverse activities, stakeholders, and resources while ensuring project goals are met efficiently. The complex nature of the SDLC process leaves plenty of scope for human error, which impacts the overall business cost. This paper introduces AI-Analyst, an AI-assisted framework developed using the transformer-based model with more than 150 million parameters to assist with SDLC management. It minimizes manual effort errors, optimizes resource allocation, and improves decision-making processes, resulting in substantial cost savings. The statistical analysis shows that it saves around 53.33% of costs in …

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Developing International Guidance To Make Impact Assessment Follow-Up Happen–Reflections On An Interactive Design Process, Angus Morrison-Saunders, Jos Arts, Annette Nykiel, Bruce Muir, Richard Morgan, Patricia Fitzpatrick, Ciaran O’Faircheallaigh, Alberto Fonseca, Charlotta Faith-Ell, Ainhoa González, Jan Albert Wessels, Gesa Geißler, Luis Sánchez, Urmila Jha-Thakur, William Ross, John Glasson Jan 2024

Developing International Guidance To Make Impact Assessment Follow-Up Happen–Reflections On An Interactive Design Process, Angus Morrison-Saunders, Jos Arts, Annette Nykiel, Bruce Muir, Richard Morgan, Patricia Fitzpatrick, Ciaran O’Faircheallaigh, Alberto Fonseca, Charlotta Faith-Ell, Ainhoa González, Jan Albert Wessels, Gesa Geißler, Luis Sánchez, Urmila Jha-Thakur, William Ross, John Glasson

Research outputs 2022 to 2026

To advance impact assessment (IA) practice worldwide the International Association for Impact Assessment (IAIA) has long promoted and published a series of international best practice principles, including the recently revised best practice principles for IA follow-up. IA follow-up refers to any kind of undertaking that seeks to ‘understand the outcomes of projects or plans’ that have been subject to IA. To support the implementation of these principles worldwide, a global guidance document has been developed (published by IAIA in 2024). The aims of this paper are to report on the approach undertaken to this guidance, applying a Delphi method, and …

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Identifying And Filling Critical Knowledge Gaps Can Optimize Financial Viability Of Blue Carbon Projects In Tidal Wetlands, Tim J.B. Carruthers, S. Beaux Jones, Megan K. Terrell, Jonathan F. Scheibly, Brendan J. Player, Valerie A. Black, Justin R. Ehrenwerth, Patrick D. Biber, Rod M. Connolly, Steve Crooks, Jason P. Curole, Kelly M. Darnell, Alyssa M. Dausman, Allison L. Dejong, Shawn M. Doyle, Christopher R. Esposito, Daniel A. Friess, James W. Fourqurean, Ioannis Y. Georgiou, Gabriel D. Grimsditch, Songjie He, Eva R. Hillmann, Guerry O. Holm, Jennifer Howard, Hoonshin Jung, Stacy D. Jupiter, Paul S. Lavery Jan 2024

Identifying And Filling Critical Knowledge Gaps Can Optimize Financial Viability Of Blue Carbon Projects In Tidal Wetlands, Tim J.B. Carruthers, S. Beaux Jones, Megan K. Terrell, Jonathan F. Scheibly, Brendan J. Player, Valerie A. Black, Justin R. Ehrenwerth, Patrick D. Biber, Rod M. Connolly, Steve Crooks, Jason P. Curole, Kelly M. Darnell, Alyssa M. Dausman, Allison L. Dejong, Shawn M. Doyle, Christopher R. Esposito, Daniel A. Friess, James W. Fourqurean, Ioannis Y. Georgiou, Gabriel D. Grimsditch, Songjie He, Eva R. Hillmann, Guerry O. Holm, Jennifer Howard, Hoonshin Jung, Stacy D. Jupiter, Paul S. Lavery

Research outputs 2022 to 2026

One of the world’s largest “blue carbon” ecosystems, Louisiana’s tidal wetlands on the US Gulf of Mexico coast, is rapidly being lost. Louisiana’s strong legal, regulatory, and monitoring framework, developed for one of the world’s largest tidal wetland systems, provides an opportunity for a programmatic approach to blue carbon accreditation to support restoration of these ecologically and economically important tidal wetlands. Louisiana’s coastal wetlands span ∼1.4 million ha and accumulate 5.5–7.3 Tg yr−1 of blue carbon (organic carbon), ∼6%–8% of tidal marsh blue carbon accumulation globally. Louisiana has a favorable governance framework to advance blue carbon accreditation, due to centralized …

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Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk Jan 2024

Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk

OES Faculty Publications

Tidally influenced groundwater systems in coastal environments represent important mixing zones of fresh groundwater and circulating seawater, manifesting as submarine groundwater discharge (SGD). Water circulation induced by tidal pumping enhances the exchange of chemicals between aquifers and coastal waters and thereby influences the biogeochemistry of coastal zones. Here, we report the results of an SGD field study conducted at a steep, mega-tidal sand and gravel beach along the Canadian coast of the Bay of Fundy, a region with the world's highest tides (semi-diurnal tidal ranges exceeding 10 m). Several physical and geochemical measurement techniques were employed to document the spatiotemporal …

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Mapping Seagrass Distribution And Abundance: Comparing Areal Cover And Biomass Estimates Between Space-Based And Airborne Imagery, Victoria J. Hill, Richard C. Zimmerman, Dorothy A. Byron, Kenneth L. Heck Jr. Jan 2024

Mapping Seagrass Distribution And Abundance: Comparing Areal Cover And Biomass Estimates Between Space-Based And Airborne Imagery, Victoria J. Hill, Richard C. Zimmerman, Dorothy A. Byron, Kenneth L. Heck Jr.

OES Faculty Publications

This study evaluated the effectiveness of Planet satellite imagery in mapping seagrass coverage in Santa Rosa Sound, Florida. We compared very-high-resolution aerial imagery (0.3 m) collected in September 2022 with high-resolution Planet imagery (~3 m) captured during the same period. Using supervised classification techniques, we accurately identified expansive, continuous seagrass meadows in the satellite images, successfully classifying 95.5% of the 11.18 km² of seagrass area delineated manually from the aerial imagery. Our analysis utilized an occurrence frequency (OF) product, which was generated by processing ten clear-sky images collected between 8 and 25 September 2022 to determine the frequency with which …

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A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington Jan 2024

A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington

OES Faculty Publications

A new, simplified protocol for determining particulate adenosine triphosphate (ATP) levels allows for the assessment of microbial biomass distribution in aquatic systems at a high temporal and spatial resolution. A comparison of ATP data with related variables, such as particulate carbon, nitrogen, chlorophyll, and turbidity in pelagic samples, yielded significant and strong correlations in a gradient from the tributaries of the Chesapeake Bay (sigma-t = 8) to the open North Atlantic (sigma-t = 29). Correlations varied between ATP and biomass depending on the microscopic method employed. Despite the much greater effort involved, biomass determined by microscopy correlated poorly with other …

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Re-Evaluating Hydrogen Sulfide As A Sink For Cadmium And Zinc In The Oxic To Suboxic Upper Water Column Of The Pacific Ocean, N. R. Buckley, E. E. Black, J. A. Kenyon, N. T. Lanning, M. Sieber, T. M. Conway, J. N. Fitzsimmons, G. A. Cutter Jan 2024

Re-Evaluating Hydrogen Sulfide As A Sink For Cadmium And Zinc In The Oxic To Suboxic Upper Water Column Of The Pacific Ocean, N. R. Buckley, E. E. Black, J. A. Kenyon, N. T. Lanning, M. Sieber, T. M. Conway, J. N. Fitzsimmons, G. A. Cutter

OES Faculty Publications

Hydrogen sulfide is produced by heterotrophic bacteria in anoxic waters and via carbonyl sulfide hydrolysis and phytoplankton emissions under oxic conditions. Apparent losses of dissolved cadmium (dCd) and zinc (dZn) in oxygen minimum zones (OMZs) of the Atlantic and Pacific Oceans have been attributed to metal-sulfide precipitation formed via dissimilatory sulfate reduction. It has also been argued that such a removal process could be a globally important sink for dCd and dZn. However, our studies from the North Pacific OMZ show that dissolved and particulate sulfide concentrations are insufficient to support the removal of dCd via precipitation. In contrast, apparent …

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Last Millennium Hurricane Activity Linked To Endogenous Climate Variability, Wenchang Yang, Elizabeth Wallace, Gabriel A. Vecchi, Jeffrey P. Donnelly, Julien Emile-Geay, Gregory J. Hakim, Larry W. Horowitz, Richard M. Sullivan, Robert Tardif, Peter J. Van Hengstum, Tyler S. Winkler Jan 2024

Last Millennium Hurricane Activity Linked To Endogenous Climate Variability, Wenchang Yang, Elizabeth Wallace, Gabriel A. Vecchi, Jeffrey P. Donnelly, Julien Emile-Geay, Gregory J. Hakim, Larry W. Horowitz, Richard M. Sullivan, Robert Tardif, Peter J. Van Hengstum, Tyler S. Winkler

OES Faculty Publications

Despite increased Atlantic hurricane risk, projected trends in hurricane frequency in the warming climate are still highly uncertain, mainly due to short instrumental record that limits our understanding of hurricane activity and its relationship to climate. Here we extend the record to the last millennium using two independent estimates: a reconstruction from sedimentary paleohurricane records and a statistical model of hurricane activity using sea surface temperatures (SSTs). We find statistically significant agreement between the two estimates and the late 20th century hurricane frequency is within the range seen over the past millennium. Numerical simulations using a hurricane-permitting climate model suggest …

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Quantifying Potential Marine Debris Sources And Potential Threats To Penguins On The West Antarctic Peninsula, Katherine L. Gallagher, Megan A. Cimino, Michael S. Dinniman, Heather J. Lynch Jan 2024

Quantifying Potential Marine Debris Sources And Potential Threats To Penguins On The West Antarctic Peninsula, Katherine L. Gallagher, Megan A. Cimino, Michael S. Dinniman, Heather J. Lynch

OES Faculty Publications

Marine pollution is becoming ubiquitous in the environment. Observations of pollution on beaches, in the coastal ocean, and in organisms in the Antarctic are becoming distressingly common. Increasing human activity, growing tourism, and an expanding krill fishing industry along the West Antarctic Peninsula all represent potential sources of plastic pollution and other debris (collectively referred to as debris) to the region. However, the sources of these pollutants from point (pollutants released from discrete sources) versus non-point (pollutants from a large area rather than a specific source) sources are poorly understood. We used buoyant simulated particles released in a high-resolution physical …

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Editorial: The Marine Iodine Cycle, Past, Present, And Future, Rosie Chance, Gregory A. Cutter, Dalton S. Hardisty, Anoop S. Mahajan Jan 2024

Editorial: The Marine Iodine Cycle, Past, Present, And Future, Rosie Chance, Gregory A. Cutter, Dalton S. Hardisty, Anoop S. Mahajan

OES Faculty Publications

In this Research Topic, we bring together ten articles from the diverse research communities interested in the marine iodine cycle, including paleoceanographers, atmospheric chemists, and biogeochemists. The physical chemistry underpinning iodine’s chemical speciation and transformations in the ocean is reviewed by Luther; this paper provides a theoretical basis for the field observations presented in this Research Topic.

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4500-Year Paleohurricane Record From The Western Gulf Of Mexico, Coastal Central Tx, Usa, Sarah B. Monica, Davin J. Wallace, Elizabeth J. Wallace, Xiaojing Du, Sylvia G. Dee, John B. Anderson Jan 2024

4500-Year Paleohurricane Record From The Western Gulf Of Mexico, Coastal Central Tx, Usa, Sarah B. Monica, Davin J. Wallace, Elizabeth J. Wallace, Xiaojing Du, Sylvia G. Dee, John B. Anderson

OES Faculty Publications

Texas receives the second-highest number of tropical cyclone (TC) landfalls per year in the United States. At present, long-term TC projections from climate models remain uncertain due to the short and biased nature of Atlantic TC observations. Sediment archives of past storms can help extend the observational record of TC strikes over the past few millennia. When a TC makes landfall along the central Texas coast, coastal downwelling channels and storm currents transport and deposit coarse sediment to a zone of rapid accumulation along the shelf, known as the Texas Mud Blanket (TMB). This “backwash” process results in expansive storm …

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Ice-Marginal Volcanic Sequence In Iceland Found On A Nondescript Gradual Hillslope: An Unexpected Record Of Ice Thickness Late In Deglaciation, Audrey R. Putnam, Kristen L. Siebach, Candice C. Bedford, Sarah L. Simpson, Michael T. Thorpe, Joseph J. Tamborski Jan 2024

Ice-Marginal Volcanic Sequence In Iceland Found On A Nondescript Gradual Hillslope: An Unexpected Record Of Ice Thickness Late In Deglaciation, Audrey R. Putnam, Kristen L. Siebach, Candice C. Bedford, Sarah L. Simpson, Michael T. Thorpe, Joseph J. Tamborski

OES Faculty Publications

Volcanism increases when glaciers melt because isostatic rebound during deglaciation decreases the pressure on the mantle, which enhances decompression melting. Anthropogenic climate change is now causing ice sheets and valley glaciers to melt around the world and this deglaciation could stimulate volcanic activity and associated hazards in Iceland, Antarctica, Alaska, and Patagonia. However, current model predictions for volcanic activity associated with anthropogenic deglaciation in Iceland are poorly constrained, in part due to uncertainties in past volcanic output over time compared to ice sheet arrangements. Further work specifically characterizing glaciovolcanic and ice-marginal volcanoes in Iceland is needed to reconstruct volcanic output …

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A Proxy System Modeling Approach To Combining Tree-Ring And Sediment-Based Paleotempestological Records, Elizabeth J. Wallace, Sylvia Dee, Joshua Bregy, Kerry A. Emanuel Jan 2024

A Proxy System Modeling Approach To Combining Tree-Ring And Sediment-Based Paleotempestological Records, Elizabeth J. Wallace, Sylvia Dee, Joshua Bregy, Kerry A. Emanuel

OES Faculty Publications

The short and biased observational record of tropical cyclones (TCs) limits scientific understanding of how these destructive storms respond to climate forcing. Paleohurricane records use natural archives (tree rings, coarse-grained sediment) to reconstruct TC properties (frequency and intensity of rainfall, wind) over the past few hundreds to thousands of years. However, different sensitivities and sampling biases in the various paleohurricane proxies restrict our ability to compile these records into regional or basin-scale TC estimates. Here we test how well pseudo tree-ring records of paleohurricanes capture TC rainfall and occurrence. Using a large set of statistically downscaled storms forced with the …

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Contrasting Nitrogen Dynamics Across The Mid-Atlantic Bight Shelfbreak Front: Insights From Nitrate Dual Isotopes And Nitrifier Gene Abundance, Yifan Zhu, Margaret R. Mulholland, Corday R. Selden, Dennis J. Mcgillicuddy Jr., Josie Mottram, P. Dreux Chappell, Weifang Gordon Zhang, Julie Granger, Katherine E. Crider, Meredith G. Meyer, Peter W. Bernhardt, Hilde Oliver, Sophie Clayton Jan 2024

Contrasting Nitrogen Dynamics Across The Mid-Atlantic Bight Shelfbreak Front: Insights From Nitrate Dual Isotopes And Nitrifier Gene Abundance, Yifan Zhu, Margaret R. Mulholland, Corday R. Selden, Dennis J. Mcgillicuddy Jr., Josie Mottram, P. Dreux Chappell, Weifang Gordon Zhang, Julie Granger, Katherine E. Crider, Meredith G. Meyer, Peter W. Bernhardt, Hilde Oliver, Sophie Clayton

OES Faculty Publications

Observations and model studies suggest that front dynamics can enhance phytoplankton productivity. This study tested whether frontal systems also increase the abundance of nitrifying microbes and nitrogen recycling during repeat sampling transects across the Mid‐Atlantic Bight shelfbreak in July 2019. We measured ammonium concentrations, nitrate dual isotopes (δ15N, δ18O), and ammonia monooxygenase subunit A (amoA) genes of ammonia‐oxidizing archaea (AOA) and bacteria (AOB). In subsurface shelf waters, ammonium concentrations exceeded 2 μmol L−1, due to a temporary imbalance in regeneration from sinking particles and subsequent nitrification. The inverse correlation between nitrate δ15 …

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Widespread Crab Burrows Enhance Greenhouse Gas Emissions From Coastal Blue Carbon Ecosystems, Kai Xiao, Yuchen Wu, Feng Pan, Yingrong Huang, Hebo Peng, Meiqing Lu, Yan Zhang, Hailong Li, Yan Zheng, Chunmiao Zheng, Yan Liu, Nengwan Chen, Leilei Xiao, Guangxuan Han, Yasong Li, Pei Xin, Ruili Li, Bochao Xu, Faming Wang, Joseph J. Tamborski, Alicia M. Wilson, Daniel M. Alongi, Isaac R. Santos Jan 2024

Widespread Crab Burrows Enhance Greenhouse Gas Emissions From Coastal Blue Carbon Ecosystems, Kai Xiao, Yuchen Wu, Feng Pan, Yingrong Huang, Hebo Peng, Meiqing Lu, Yan Zhang, Hailong Li, Yan Zheng, Chunmiao Zheng, Yan Liu, Nengwan Chen, Leilei Xiao, Guangxuan Han, Yasong Li, Pei Xin, Ruili Li, Bochao Xu, Faming Wang, Joseph J. Tamborski, Alicia M. Wilson, Daniel M. Alongi, Isaac R. Santos

OES Faculty Publications

Fiddler crabs, as coastal ecosystem engineers, play a crucial role in enhancing biodiversity and accelerating the flow of material and energy. Here we show how widespread crab burrows modify the carbon sequestration capacity of different habitats across a large climatic gradient. The process of crab burrowing results in the reallocation of sediment organic carbon and humus. Crab burrows can increase more greenhouse gases emissions compared to the sediment matrix (CO2: by 17-30%; CH4: by 49-141%). Straightforward calculations indicate that these increased emissions could offset 35-134% of sediment carbon burial in these two ecosystems. This research highlights the complex interactions between …

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Garbage In ≠ Garbage Out: Exploring Gan Resilience To Image Training Set Degradations, Nicholas Crino, Bruce A. Cox, Nathan B. Gaw Jan 2024

Garbage In ≠ Garbage Out: Exploring Gan Resilience To Image Training Set Degradations, Nicholas Crino, Bruce A. Cox, Nathan B. Gaw

Faculty Publications

Generative Adversarial Networks (GANs) have received immense attention in recent years due to their ability to capture complex, high-dimensional data distributions without the need for extensive labeling. Since their conception in 2014, a wide array of GAN variants have been proposed featuring alternative architectures, optimizers, and loss functions with the goal of improving performance and training stability. This manuscript focuses on quantifying the resilience of a GAN architecture to specific modes of image degradation. We conduct systematic experimentation to empirically determine the effects of 10 fundamental image degradation modes, applied to the training image dataset, on the Fréchet inception distance …

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Why The Ethical Use Of Ai Matters For Your Career, Jack Mcguire, David De Cremer, Yorck Hesselbarth, Leander De Schutter Jan 2024

Why The Ethical Use Of Ai Matters For Your Career, Jack Mcguire, David De Cremer, Yorck Hesselbarth, Leander De Schutter

Research Collection Lee Kong Chian School Of Business

In the contemporary digital era, innovations such as artificial intelligence (AI) are profoundly transforming the business landscape (De Cremer, 2020). The buzz surrounding ChatGPT, coupled with recent assertions about the sentience of Google’s LaMDA, a large language model, underscore the prominence of chatbot technology in these advancements (Adamopoulou & Moussiades, 2020; Ryu & Lee, 2018; Tiku, 2022). Customer-oriented chatbots, an emergent application of this tech, offer unparalleled efficiency and cost-effectiveness, operating ceaselessly and responding to client inquiries in real time (Salesforce, Research, 2019). Yet, amidst these advantages lies an ethical conundrum. Customers cherish genuine human interaction and can become quickly …

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Kinodynamic Motion Planning For A System With Squid Dynamics, Logan E. Beaver, Cong Wei, Wei-Kuo Yen Jan 2024

Kinodynamic Motion Planning For A System With Squid Dynamics, Logan E. Beaver, Cong Wei, Wei-Kuo Yen

Mechanical & Aerospace Engineering Faculty Publications

This paper introduces a path planning algorithm for a system with squid dynamics in a cluttered environment. We capture the complex interactions of fin, arms, and body patterning by analyzing experimental data collected from observing squid motion. We extract nine motion primitives to build the control sequence for a time-optimal trajectory. This task is formulated as a mixed-integer program, and we generate the minimum-time trajectory using a sample-based approach. Numerical simulations illustrate the efficacy of this strategy and motivate ongoing and future efforts to exploration of squid motion features, improvement of the modeling, and experimental demonstrations of the motion planning …

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ประสิทธิภาพของการทำนายความเสี่ยงการเกิดโรคเบาหวานร่วมกับความเสี่ยงการเกิดโรคความดันโลหิตสูงด้วยวิธีการเรียนรู้เชิงลึกสำหรับการจำแนกประเภทหลายเลเบล, วรรษา สุดใจ Jan 2024

ประสิทธิภาพของการทำนายความเสี่ยงการเกิดโรคเบาหวานร่วมกับความเสี่ยงการเกิดโรคความดันโลหิตสูงด้วยวิธีการเรียนรู้เชิงลึกสำหรับการจำแนกประเภทหลายเลเบล, วรรษา สุดใจ

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในทางการแพทย์ การเรียนรู้เชิงลึกนิยมนำมาใช้ในการสร้างตัวแบบพยากรณ์ซึ่งค่อนข้างให้ผลที่ดีกว่าเมื่อเทียบกับตัวแบบดั้งเดิมแต่บางครั้งผู้ป่วยสามารถเป็นโรคพร้อมกันได้มากกว่าหนึ่งโรค การเรียนรู้เชิงลึกจึงถูกพัฒนาให้สามารถทำนายพร้อมกันได้หลายโรค เรียกว่าโครงข่ายประสาทเทียมประเภทจำแนกหลายเลเบล ถึงแม้โครงข่ายประสาทเทียมจะมีความสามารถที่ดีสำหรับการพยากรณ์แต่ยังมีความท้าทายในข้อมูลบางกลุ่มที่ข้อมูลมีจำกัด วิทยานิพนธ์ฉบับนี้จึงมีความสนใจที่จะทำการศึกษาโดยต้องการเพิ่มประสิทธิภาพของตัวแบบโดยรวมด้วยการใช้เลเบลผลลัพธ์ที่เกี่ยวข้องกันมาศึกษาผ่านข้อมูลโรคเบาหวานและโรคความดันโลหิตสูงซึ่งเป็นโรคที่มักเกิดร่วมกัน แบ่งการทดลองเป็นสองส่วนคือส่วนข้อมูลจำลองและข้อมูลจริงเพื่อเปรียบเทียบระหว่างโครงข่ายประสาทเทียมแบบป้อนไปข้างหน้าหลายเลเบลกับหนึ่งเลเบล ผลการศึกษาพบว่าในโครงข่ายประสาทเทียมหลายเลเบลให้ผลที่ดีในทางทฤษฎีที่ทดสอบกับข้อมูลจำลอง แต่ในข้อมูลจริงผลลัพธ์ของการใช้เลเบลที่มีความเกี่ยวข้องกันไม่สามารถลดค่าฟังชันการสูญเสียได้อย่างมีนัยสำคัญ แต่มีข้อดีคือช่วยลดความรุนแรงของปัญหา overfit ได้และสามารถให้ประสิทธิภาพการพยากรณ์ยังคงเทียบเท่าการใช้หนึ่งเลเบล

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First-Order Geometric Integer-Valued Autoregressive Model With Covariates, Adisak Seedamad Jan 2024

First-Order Geometric Integer-Valued Autoregressive Model With Covariates, Adisak Seedamad

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this thesis, we propose two integer-valued time series consisting of (1) the single parameter first-order geometric integer-valued autoregressive (SGINAR(1)) model with covariates and (2) the first-order geometric integer-valued autoregressive GINAR(1) model with covariates. In our study, we obtain the innovation distribution using stationary properties and obtain moment properties of two models. In addition, we obtain parameter estimation by using the conditional least squares (CLS) method and the penalized conditional least squares (PCLS) method. Finally, we conduct simulation studies and apply to real data.

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Geomorphological Evolution Of The Mun River, Surin Province Northeastern Thailand, Chutiwat Sawangkit Jan 2024

Geomorphological Evolution Of The Mun River, Surin Province Northeastern Thailand, Chutiwat Sawangkit

Chulalongkorn University Theses and Dissertations (Chula ETD)

From 1973 to 2023, the Mun River in Surin Province, Thailand, underwent geomorphological evolution. This study examines changes in channel parameters to determine how human activity and natural processes affect river shape. This study measures changes in four important geomorphological parameters channel sinuosity, radius of curvature, channel width, and channel length by analyzing the data from C (ERT), satellite imagery, and topographic maps. A dynamic meandering process that has created oxbow lakes, neck and chute cut-offs, and other geomorphological features throughout time is visible on satellite photos. Significant morphological changes have been brought about, notably, by the building of dams, …

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