Open Research Exeter - University of Exeter
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London Urban Tree Species Classification Data
No full textThis dataset was created as part of the ongoing study on urban trees species classification in the UK. This study is a sub-project under the PhD programme titled 'Geospatial Data and AI for Enhanced Property Information Database in the UK'. The dataset includes multi-temporal spectral reflectance values of selected tree instances in the central London area. The dataset is in two parts. The first group contains spectral signatures derived from PlanetScope satellite images from 2021 to 2025, while the second group include multi-temporal spectral signatures derived from Sentinel 2A imagery from 2021 to 2025.The goal of releasing this dataset is to contribute to the remote sensing and ecological research community to advance research aimed at accurately classifying urban tree species using the multi-temporal spectral signatures approach.This dataset is released also to support the 2026 IGARSS Conference paper titled 'Towards Urban Tree Species Classification in the UK: A machine learning Instance Segmentation Approach to Multimodal Species-Classification Dataset Creation and Algorithms Development'. The International Geoscience and Remote Sensing Symposium (IGARSS) is the flagship conference of the IEEE Geoscience and Remote Sensing Society (GRSS).</p
Stochastic modeling and design of truck platooning strategies considering platoon dynamics
No full textRoad transportation via trucks is a dominant mode for long-haul freight transport across countries. However, due to their significant dependence on fossil fuels, trucks are a large contributor to carbon emissions. Hence, new technology-driven solutions such as truck platoons are gaining momentum. While platoons promise to reduce fuel costs and emissions, they may increase transportation time due to additional coordination delays, such as the time required for platoon formation. In this research, we examine the performance trade-offs between platoon fuel savings and excess delay costs resulting from waiting for platoon formation among three platoon formation strategies: intermittent, continuous, and opportunistic. We develop a novel Closed Queuing Network model that captures the dynamics of platoons, as well as the stochasticity in truck travel times, and provides realistic estimates of platoon wait times and vehicle throughput. The platoon formation delays and size-dependent travel times are modeled using merging and load-dependent nodes, respectively, and analyzed through a continuous-time Markov chain. Our study provides key insights into the impact of increasing platoon size on performance measures, including system throughput and mean waiting time. With platooning, the network throughput capacity is reduced; however, fuel savings are realized. For a given network topology, we can identify an optimal platoon formation strategy that maximizes the throughput and fuel efficiency, while simultaneously minimizing vehicle waiting costs.</p
Late glacial and Holocene marine geology, palaeoceanography and palaeoecology of the Northern Isles of Scotland
No full textMarine palaeoenvironmental data are essential for understanding how the oceans respond to climate and environmental changes. These data can be used to guide climate models and characterise the environment in which human populations develop. During the Holocene, much of the northwestern North Sea has experienced low sediment accumulation rates, inhibiting the investigation regional palaeoenvironmental change using traditional marine sediment proxies. However, on the DY150 research cruise (2022), marine sediment cores were recovered from depositional basins around Shetland and Orkney, UK. Using palaeoenvironmental datasets generated from these cores (foraminiferal assemblages, stable isotopes, sediment physical properties, ITRAX XRF, grain size, and total organic carbon) this thesis aims to increase our understanding of the Late glacial and Holocene marine geology, palaeoceanography and palaeoecology of the northwestern North Sea.
Chapters 2 and 4 investigate the sedimentary expression of the Storegga tsunami event (ca. 8,150 cal a BP), and the implications for the semi-coeval 8.2 ka cooling event. Within the Holocene mud sequences collected in the Fetlar and St Magnus basins (Shetland), coarse-grained lenses are dated to the timing of the Storegga tsunami event. These lenses show sedimentological characteristics typical of deposits created by tsunami backwash-generated debris flows. No evidence of shallow water foraminiferal species is found in the deposits, likely due to high early Holocene sedimentation rates, or the lack of gradient between species found in shallow coastal waters and at the core site. Cool water species (which are indicative of glacial age sediments) are not abundant in foraminiferal assemblages within these lenses, suggesting that reworked material originates from Holocene sediments. Despite the lack of cool water species, radiocarbon dating of carbonate material within the deposits suggests reworking of older (> 8.7 k cal a BP) material. Therefore, marine sediment records in the Storegga tsunami affected region likely do not provide a reliable palaeoceanographic record of the 8.2 ka cooling event.
Chapter 3 examines the Late glacial and Holocene palaeoceanographic record of a sediment core from the Fetlar Basin, Shetland. At the base of this record, foraminiferal assemblages and sedimentology are indicative of a cold climate, aligning with the Younger Dryas. A transition to warmer Holocene conditions occurs at 11.5 k cal a BP. During the mid-Holocene, isotope and assemblage data suggest a freshening of the water column, aligning with increased contributions of Modified North Atlantic Water, interpreted to result from an eastward expansion of the subpolar gyre (SPG). Conversely, from 4.2 ka to the present, data suggest a westward contraction of the SPG. This record highlights the connection of the North Sea to the wider North Atlantic throughout the Holocene, which has consequence for future paleoenvironmental reconstructions in the region.
Chapter 5 consists of a marine palaeoenvironmental reconstruction from a core spanning the Late glacial and Holocene in Scapa Flow, Orkney. This record aims to provide the paleoenvironmental backdrop for the pre- and presently-human occupied landscape. Data from the base of this record suggest a cool environment, coincident with terrestrial records of the Younger Dryas. During the early Holocene, the site developed into a shallow restricted basin with a stratified water column and high levels of organic matter. From 8.1 to 5.1 k cal a BP, Scapa flow transitioned from a stratified-frontal region to a well-mixed system, largely influenced by sea-level rise. From 5.1 k cal a BP to the top of the record, Scapa Flow is suggested to be a fully mixed, well oxygenated setting with active bottom water currents. The marine transition at 5.1 k cal BP occurs during the Neolithic period, but existing archaeological evidence does not suggest a synchronous shift in diet. From 5.2 k cal a BP sand content increases, however it is challenging to determine if this is a result of changing tidal dynamics or is related to Neolithic land disturbance. No evidence of nutrient enrichment related to increased population size or run-off was detected. The proxies used in this study indicate that changes in physical oceanographic processes have played a more dominant role in governing the productivity and ecosystem of Scapa Flow than human activity.</p
Late glacial and Holocene marine geology, palaeoceanography and palaeoecology of the Northern Isles of Scotland: supplement to the PhD thesis by Jane L Earland
No full textThis data is the supplement for the PhD Thesis "Late glacial and Holocene marine geology, palaeoceanography and palaeoecology of the Northern Isles of Scotland". Jane L Earland. The thesis is available in ORE at https://hdl.handle.net/10779/exe.31096174Datasets contain foraminiferal assemblage counts, foraminiferal isotope data, grain size, total organic carbon, and age models.Abstract:Marine palaeoenvironmental data are essential for understanding how the oceans respond to climate and environmental changes. These data can be used to guide climate models and characterise the environment in which human populations develop. During the Holocene, much of the northwestern North Sea has experienced low sediment accumulation rates, inhibiting the investigation regional palaeoenvironmental change using traditional marine sediment proxies. However, on the DY150 research cruise (2022), marine sediment cores were recovered from depositional basins around Shetland and Orkney, UK. Using palaeoenvironmental datasets generated from these cores (foraminiferal assemblages, stable isotopes, sediment physical properties, ITRAX XRF, grain size, and total organic carbon) this thesis aims to increase our understanding of the Late glacial and Holocene marine geology, palaeoceanography and palaeoecology of the northwestern North Sea.Chapters 2 and 4 investigate the sedimentary expression of the Storegga tsunami event (ca. 8,150 cal a BP), and the implications for the semi-coeval 8.2 ka cooling event. Within the Holocene mud sequences collected in the Fetlar and St Magnus basins (Shetland), coarse-grained lenses are dated to the timing of the Storegga tsunami event. These lenses show sedimentological characteristics typical of deposits created by tsunami backwash-generated debris flows. No evidence of shallow water foraminiferal species is found in the deposits, likely due to high early Holocene sedimentation rates, or the lack of gradient between species found in shallow coastal waters and at the core site. Cool water species (which are indicative of glacial age sediments) are not abundant in foraminiferal assemblages within these lenses, suggesting that reworked material originates from Holocene sediments. Despite the lack of cool water species, radiocarbon dating of carbonate material within the deposits suggests reworking of older (> 8.7 k cal a BP) material. Therefore, marine sediment records in the Storegga tsunami affected region likely do not provide a reliable palaeoceanographic record of the 8.2 ka cooling event.Chapter 3 examines the Late glacial and Holocene palaeoceanographic record of a sediment core from the Fetlar Basin, Shetland. At the base of this record, foraminiferal assemblages and sedimentology are indicative of a cold climate, aligning with the Younger Dryas. A transition to warmer Holocene conditions occurs at 11.5 k cal a BP. During the mid-Holocene, isotope and assemblage data suggest a freshening of the water column, aligning with increased contributions of Modified North Atlantic Water, interpreted to result from an eastward expansion of the subpolar gyre (SPG). Conversely, from 4.2 ka to the present, data suggest a westward contraction of the SPG. This record highlights the connection of the North Sea to the wider North Atlantic throughout the Holocene, which has consequence for future paleoenvironmental reconstructions in the region.Chapter 5 consists of a marine palaeoenvironmental reconstruction from a core spanning the Late glacial and Holocene in Scapa Flow, Orkney. This record aims to provide the paleoenvironmental backdrop for the pre- and presently-human occupied landscape. Data from the base of this record suggest a cool environment, coincident with terrestrial records of the Younger Dryas. During the early Holocene, the site developed into a shallow restricted basin with a stratified water column and high levels of organic matter. From 8.1 to 5.1 k cal a BP, Scapa flow transitioned from a stratified-frontal region to a well-mixed system, largely influenced by sea-level rise. From 5.1 k cal a BP to the top of the record, Scapa Flow is suggested to be a fully mixed, well oxygenated setting with active bottom water currents. The marine transition at 5.1 k cal BP occurs during the Neolithic period, but existing archaeological evidence does not suggest a synchronous shift in diet. From 5.2 k cal a BP sand content increases, however it is challenging to determine if this is a result of changing tidal dynamics or is related to Neolithic land disturbance. No evidence of nutrient enrichment related to increased population size or run-off was detected. The proxies used in this study indicate that changes in physical oceanographic processes have played a more dominant role in governing the productivity and ecosystem of Scapa Flow than human activity.</p
Risk Perception and Communication, Plugged‐In: Fifty Years of Process
No full textThirty years after Baruch Fischhoff's (1995) influential article Risk Perception and Communication Unplugged, this commentary revisits the developmental stages and conclusions outlined in this seminal paper documenting and reflecting on the development of risk communication. Fischhoff's work has shaped decades of research and practice, and while not intended in this way, many institutional efforts continue to rely on the earliest, technically focused stages. We reflect on how the field has evolved in the context of Fischhoff's stages, considering the impact of digital platforms, participatory methods, and societal change since 1995 that shape risk communication today. Building on contemporary developments and our own experiences, we propose reordering Fischhoff's stages by moving partnership to the start of the communication process. We also revise its language to better reflect inclusive, collaborative, and dialogic approaches. Key themes include the persistence of information deficit models, the ethical responsibilities of communicators, and the tensions between theory and practice in risk communication. We also reflect on a selection of Fischhoff's (1995) conclusions, identifying still-existing, and evolving issues arising 30 years later. We argue that risk communication must be reconceptualized as a relational and political practice: One that respects public agency and centers partnership, rather than serving narrow persuasive aims. Fischhoff's contribution remains inspirational, provocative and instructive. It also challenges risk communicators to think more critically about the field's future and our responsibility to communicate risk ethically, inclusively, and meaningfully.</p
Relative importance of climate versus socio-environmental development changes to 2050 in rural coastal Bangladesh—a system analysis
No full textClimate change and development are having a profound influence on the integrity of coastal Bangladesh’s people, economy and ecology with climate change widely considered the dominant driver. Our bespoke integrated assessment model (IAM) simulates these changes for rural areas by coupling physical models with economic models, considering shocks like cyclone landfalls, and utilising substantial primary/secondary datasets and stakeholder-derived future scenarios. As such, this study assesses the Bangladesh coastal system’s sensitivity to climate change and policy decisions to 2050. The IAM results suggest that flooding and salinisation have high sensitivity to climatic and environmental drivers, and agricultural productivity is strongly dependent on farming methods and investment in better crop varieties to counteract these changes. Inequality, poverty and GDP per capita are more sensitive to non-climatic drivers. Nonetheless, extreme climatic conditions do impact livelihoods due to economic damage with variable effects across different household types. At least over the next 25 years, development choices (i.e. concrete adaptation actions) will have a similar if not stronger influence on livelihoods and economic wellbeing in rural coastal Bangladesh than climate-driven environmental change. This IAM approach supports decision makers to identify sustainable development pathways that address both current socio-environmental vulnerability as well as develop a more climate-resilient future.</p
The implications of overshooting 1.5 °C on Earth system tipping elements—a review
No full textDue to insufficient emission reductions in recent years, it is increasingly likely that global warming will exceed the 1.5 °C temperature limit in the late 2020s or 2030s. As a result, several Earth system tipping elements could, at least temporarily, have their tipping points surpassed, posing risks of large-scale and profound structural change. Tipping does not always occur immediately upon crossing such a critical threshold. If the length of time the driver is beyond the critical level is short enough, tipping could still be avoided for some slow-responding elements of the climate system. An improved understanding is therefore needed of whether tipping remains avoidable, for which systems, and under what conditions. Here, we review how minimising the magnitude and duration of any temperature overshoot beyond 1.5 °C could decrease tipping risks. Tipping elements with fast response times, such as warm-water coral reefs, are especially vulnerable to overshoot. In contrast, those with slow response times, such as polar ice sheets, may be less sensitive to temporary overshoot. Potential interactions between tipping elements and additional human pressures, such as deforestation in the Amazon or pollution and overfishing of coral reef habitats, may further lower tipping points, narrowing the range of overshoot trajectories that can still avoid it. The vulnerability of many tipping elements, even under shorter overshoot conditions, underscores that global warming must peak below 2 °C above pre-industrial levels, return to below 1.5 °C as quickly as possible (i.e. within this century), and to around 1 °C thereafter to limit tipping point risks.</p
Reimagining coral reef futures
No full textCoral reefs are vital social-ecological systems, but highly vulnerable to global change and local stressors. While conveying the urgency of existential threats is paramount, bleak outlooks can become self-reinforcing, limiting capacities to act. To counter this, experts working on coral reefs in diverse geographies imagined coral reef futures through a structured visioning process. The resulting visions offer alternatives aspiring to desirability, sustainability, and equity for coral reefs. These broaden the conversation on coral reef futures, enabling discussions beyond siloed conservation, traditional management tools, or pure techno-fixes. Concepts such as earth stewardship, biocultural revitalization, and anticipatory governance emerged as essential to sustaining human well-being and enabling the viability of future coral reef ecosystems before, during, and beyond social-ecological shocks. By fostering forward-thinking dialog, these visions and narratives constitute key stepping stones to reimagining desirable relationships between people and coral reefs and speak to both anticipatory and adaptive pathways toward desired change.</p
Field effects on magnon‐induced domain wall motion in a magnetic insulator racetrack
No full textThe interactions between magnons and domain walls provide opportunities for extending the functionality of magnonic and spintronic devices. Building on our previous demonstration of field-free magnon-induced domain wall motion in low-damping bismuth-substituted yttrium iron garnet, this work explores the underlying dynamics and the effects of small magnetic fields on magnon-driven domain wall motion. Time-resolved imaging unveils the dynamical response of the garnet track to the RF signal, as well as the excitation of oscillations in a domain wall placed in the track. Magnon transmission is detected over distances of 70 µm from which a damping parameter is extracted. The combined influence of small out-of-plane fields (≤ 2 mT) and magnons on domain wall depinning and motion enables direction control. The findings culminate in the demonstration of robust, bidirectional domain wall motion up to 40 µm, establishing a pathway toward field-tunable, low-loss magnonic devices.</p
A systematic review of the impact of GenAI on learning performance, AI hallucinations, and problem-solving in computer science education
No full textThis systematic review synthesizes 64 empirical studies to examine how Generative AI (GenAI) shapes learning in Computer Science Education (CSE), particularly in programming, debugging, algorithmic reasoning, and computational problem-solving contexts. Grounded in Constructivist, Sociocultural, Cognitive Load, Adaptive Learning, and Metacognitive Learning theories, the review adopts an integrative perspective to analyze how GenAI-driven adaptivity, AI output qualities, hallucination dynamics, and cognitive–affective regulation influence learners' interpretation, cognitive processing, and learning outcomes. Findings reveal a dual impact of GenAI in CSE. On the negative side, hallucinated or misleading outputs can increase extraneous cognitive load during programming and debugging and promote over-reliance on system-generated content. They may also perpetuate inequities due to limited access in low-resource settings or insufficient support for culturally and linguistically diverse learners. These effects can disrupt error detection, self-monitoring, and problem-solving, leading to impaired learning performance and widened educational disparities. On the positive side, when embedded within structured, equitable, and pedagogically grounded environments, GenAI supports reflective programming practice by promoting self-monitoring, verification, and strategic adjustment, thereby enhancing problem-solving skills, engagement, and personalized learning outcomes. By framing learning performance, hallucination dynamics, and problem-solving as interconnected dimensions of GenAI-supported computing education, this review provides a theoretically coherent and pedagogically grounded lens for understanding how GenAI reshapes learning in CSE. The review's novelty lies in its integrative conceptual framework, offering actionable insights for designing equitable, cognitively balanced, and instructionally effective GenAI-supported learning environments.</p