537 research outputs found
Evaluating the sustainability and resiliency of local food systems
With an ever-rising global population and looming environmental challenges such as climate change and soil degradation, it is imperative to increase the sustainability of food production. The drastic rise in food insecurity during the COVID-19 pandemic has further shown a pressing need to increase the resiliency of food systems. One strategy to reduce the dependence on complex, vulnerable global supply chains is to strengthen local food systems, such as by producing more food in cities. This thesis uses an interdisciplinary, food systems approach to explore aspects of sustainability and resiliency within local food systems.
Lifecycle assessment (LCA) was used to evaluate how farm scale, distance to consumer, and management practices influence environmental impacts for different local agriculture models in two case study locations: Georgia, USA and England, UK. Farms were grouped based on urbanisation level and management practices, including: urban organic, peri-urban organic, rural organic, and rural conventional. A total of 25 farms and 40 crop lifecycles were evaluated, focusing on two crops (kale and tomatoes) and including impacts from seedling production through final distribution to the point of sale. Results were extremely sensitive to the allocation of composting burdens (decomposition emissions), with impact variation between organic farms driven mainly by levels of compost use. When composting burdens were attributed to compost inputs, the rural conventional category in the U.S. and the rural organic category in the UK had the lowest average impacts per kg sellable crop produced, including the lowest global warming potential (GWP). However, when subtracting avoided burdens from the municipal waste stream from compost inputs, trends reversed entirely, with urban or peri-urban farm categories having the lowest impacts (often negative) for GWP and marine eutrophication. Overall, farm management practices were the most important factor driving environmental impacts from local food supply chains.
A soil health assessment was then performed on a subset of the UK farms to provide insight to ecosystem services that are not captured within LCA frameworks. Better soil health was observed in organically-farmed and uncultivated soils compared to conventionally farmed soils, suggesting higher ecosystem service provisioning as related to improved soil structure, flood mitigation, erosion control, and carbon storage. However, relatively high heavy metal concentrations were seen on urban and peri-urban farms, as well as those located in areas with previous mining activity. This implies that there are important services and disservices on farms that are not captured by LCAs.
Zooming out from a focus on food production, a qualitative methodology was used to explore experiences of food insecurity and related health and social challenges during the COVID-19 pandemic. Fourteen individuals receiving emergency food parcels from a community food project in Sheffield, UK were interviewed. Results showed that maintaining food security in times of crisis requires a diverse set of individual, household, social, and place-based resources, which were largely diminished or strained during the pandemic. Drawing upon social capital and community support was essential to cope with a multiplicity of hardship, highlighting a need to develop community food infrastructure that supports ideals of mutual aid and builds connections throughout the food supply chain. Overall, this thesis shows that a range of context-specific solutions are required to build sustainable and resilient food systems. This can be supported by increasing local control of food systems and designing strategies to meet specific community needs, whilst still acknowledging a shared global responsibility to protect ecosystem, human, and planetary health
Advances and Applications of DSmT for Information Fusion. Collected Works, Volume 5
This fifth volume on Advances and Applications of DSmT for Information Fusion collects theoretical and applied contributions of researchers working in different fields of applications and in mathematics, and is available in open-access. The collected contributions of this volume have either been published or presented after disseminating the fourth volume in 2015 in international conferences, seminars, workshops and journals, or they are new. The contributions of each part of this volume are chronologically ordered.
First Part of this book presents some theoretical advances on DSmT, dealing mainly with modified Proportional Conflict Redistribution Rules (PCR) of combination with degree of intersection, coarsening techniques, interval calculus for PCR thanks to set inversion via interval analysis (SIVIA), rough set classifiers, canonical decomposition of dichotomous belief functions, fast PCR fusion, fast inter-criteria analysis with PCR, and improved PCR5 and PCR6 rules preserving the (quasi-)neutrality of (quasi-)vacuous belief assignment in the fusion of sources of evidence with their Matlab codes.
Because more applications of DSmT have emerged in the past years since the apparition of the fourth book of DSmT in 2015, the second part of this volume is about selected applications of DSmT mainly in building change detection, object recognition, quality of data association in tracking, perception in robotics, risk assessment for torrent protection and multi-criteria decision-making, multi-modal image fusion, coarsening techniques, recommender system, levee characterization and assessment, human heading perception, trust assessment, robotics, biometrics, failure detection, GPS systems, inter-criteria analysis, group decision, human activity recognition, storm prediction, data association for autonomous vehicles, identification of maritime vessels, fusion of support vector machines (SVM), Silx-Furtif RUST code library for information fusion including PCR rules, and network for ship classification.
Finally, the third part presents interesting contributions related to belief functions in general published or presented along the years since 2015. These contributions are related with decision-making under uncertainty, belief approximations, probability transformations, new distances between belief functions, non-classical multi-criteria decision-making problems with belief functions, generalization of Bayes theorem, image processing, data association, entropy and cross-entropy measures, fuzzy evidence numbers, negator of belief mass, human activity recognition, information fusion for breast cancer therapy, imbalanced data classification, and hybrid techniques mixing deep learning with belief functions as well
Evaluation and optimisation of traction system for hybrid railway vehicles
Over the past decade, energy and environmental sustainability in urban rail transport have become increasingly important. Hybrid transportation systems present a multifaceted challenge, encompassing aspects such as hydrogen production, refuelling station infrastructure, propulsion system topology, power source sizing, and control. The evaluation and optimisation of these aspects are critical for the adaptation and commercialisation of hybrid railway vehicles. While there has been significant progress in the development of hybrid railway vehicles, further improvements in propulsion system design are necessary.
This thesis explores strategies to achieve this ambitious goal by substituting diesel trains with hybrid trains. However, limited research has assessed the operational performance of replacing diesel trains with hybrid trains on the same tracks. This thesis develops various optimisation techniques for evaluating and refining the hybrid traction system to address this gap.
In this research's first phase, the author developed a novel Hybrid Train Simulator designed to analyse driving performance and energy flow among multiple power sources, such as internal combustion engines, electrification, fuel cells, and batteries. The simulator incorporates a novel Automatic Smart Switching Control technique, which scales power among multiple power sources based on the route gradient for hybrid trains. This smart switching approach enhances battery and fuel cell life and reduces maintenance costs by employing it as needed, thereby eliminating the forced charging and discharging of excessively high currents. Simulation results demonstrate a 6% reduction in energy consumption for hybrid trains equipped with smart switching compared to those without it.
In the second phase of this research, the author presents a novel technique to solve the optimisation problem of hybrid railway vehicle traction systems by utilising evolutionary and numerical optimisation techniques. The optimisation method employs a nonlinear programming solver, interpreting the problem via a non-convex function combined with an efficient "Mayfly algorithm." The developed hybrid optimisation algorithm minimises traction energy while using limited power to prevent unnecessary load on power sources, ensuring their prolonged life. The algorithm takes into account linear and non-linear variables, such as velocity, acceleration, traction forces, distance, time, power, and energy, to address the hybrid railway vehicle optimisation problem, focusing on the energy-time trade-off. The optimised trajectories exhibit an average reduction of 16.85% in total energy consumption, illustrating the algorithm's effectiveness across diverse routes and conditions, with an average increase in journey times of only 0.40% and a 15.18% reduction in traction power. The algorithm achieves a well-balanced energy-time trade-off, prioritising energy efficiency without significantly impacting journey duration, a critical aspect of sustainable transportation systems.
In the third phase of this thesis, the author introduced artificial neural network models to solve the optimisation problem for hybrid railway vehicles. Based on time and power-based architecture, two ANN models are presented, capable of predicting optimal hybrid train trajectories. These models tackle the challenge of analysing large datasets of hybrid railway vehicles. Both models demonstrate the potential for efficiently predicting hybrid train target parameters. The results indicate that both ANN models effectively predict a hybrid train's critical parameters and trajectory, with mean errors ranging from 0.19% to 0.21%. However, the cascade-forward neural network topology in the time-based architecture outperforms the feed-forward neural network topology in terms of mean squared error and maximum error in the power-based architecture. Specifically, the cascade-forward neural network topology within the time-based structure exhibits a slightly lower MSE and maximum error than its power-based counterpart. Moreover, the study reveals the average percentage difference between the benchmark and FFNN/CNFN trajectories, highlighting that the time-based architecture exhibits lower differences (0.18% and 0.85%) compared to the power-based architecture (0.46% and 0.92%)
Diversifying Emergent Behaviours with Age-Layered MAP-Elites
Emergent behaviour can arise unexpectedly as a by-product of the complex interactions of an autonomous system, and with the increasing desire for such systems, emergent behaviour has become an important area of interest for AI research. One aspect of this research is in searching for a diverse set of emergent behaviours which not only provides a useful tool for finding unwanted emergent behaviour, but also in finding interesting emergent behaviour. The multi-dimensional archive of phenotypic elites (MAP-Elites) algorithm is a popular evolutionary algorithm which returns a highly diverse set of elite solutions at the end of a run. The population is separated into a grid-like feature space defined by a set of behaviour dimensions specified by the user where each cell of the grid corresponds to a unique behaviour combination. The algorithm is conceptually simple and effective at producing high-quality, diverse solutions, but it comes with a major limitation on its exploratory capabilities. With each additional behaviour, the set of solutions grows exponentially, making high-dimensional feature spaces infeasible. This thesis proposes an option for increasing behaviours with a novel Age-Layered MAP-Elites (ALME) algorithm where the population is separated into age layers and each layer has its own feature space. By using different behaviours in the different layers, the population migrates up through the layers experiencing selective pressure towards different behaviours. This algorithm is applied to a simulated intelligent agent environment to observe interesting emergent behaviours. It is observed that ALME is capable of producing a set of solutions with diversity in all behaviour dimensions while keeping the final population size low. It is also observed that ALME is capable of filling its top layer feature space more consistently than MAP-Elites with the same behaviour dimensions
Managing distributed situation awareness in a team of agents
The research presented in this thesis investigates the best ways to manage Distributed Situation Awareness (DSA) for a team of agents tasked to conduct search activity with limited resources (battery life, memory use, computational power, etc.). In the first part of the thesis, an algorithm to coordinate agents (e.g., UAVs) is developed. This is based on Delaunay triangulation with the aim of supporting efficient, adaptable, scalable, and predictable search. Results from simulation and physical experiments with UAVs show good performance in terms of resources utilisation, adaptability, scalability, and predictability of the developed method in comparison with the existing fixed-pattern, pseudorandom, and hybrid methods. The second aspect of the thesis employs Bayesian Belief Networks (BBNs) to define and manage DSA based on the information obtained from the agents' search activity. Algorithms and methods were developed to describe how agents update the BBN to model the system’s DSA, predict plausible future states of the agents’ search area, handle uncertainties, manage agents’ beliefs (based on sensor differences), monitor agents’ interactions, and maintains adaptable BBN for DSA management using structural learning. The evaluation uses environment situation information obtained from agents’ sensors during search activity, and the results proved superior performance over well-known alternative methods in terms of situation prediction accuracy, uncertainty handling, and adaptability. Therefore, the thesis’s main contributions are (i) the development of a simple search planning algorithm that combines the strength of fixed-pattern and pseudorandom methods with resources utilisation, scalability, adaptability, and predictability features; (ii) a formal model of DSA using BBN that can be updated and learnt during the mission; (iii) investigation of the relationship between agents search coordination and DSA management
Bio-inspired optimization in integrated river basin management
Water resources worldwide are facing severe challenges in terms of quality and quantity. It is essential to conserve, manage, and optimize water resources and their quality through integrated water resources management (IWRM). IWRM is an interdisciplinary field that works on multiple levels to maximize the socio-economic and ecological benefits of water resources. Since this is directly influenced by the river’s ecological health, the point of interest should start at the basin-level. The main objective of this study is to evaluate the application of bio-inspired optimization techniques in integrated river basin management (IRBM). This study demonstrates the application of versatile, flexible and yet simple metaheuristic bio-inspired algorithms in IRBM.
In a novel approach, bio-inspired optimization algorithms Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) are used to spatially distribute mitigation measures within a basin to reduce long-term annual mean total nitrogen (TN) concentration at the outlet of the basin. The Upper Fuhse river basin developed in the hydrological model, Hydrological Predictions for the Environment (HYPE), is used as a case study. ACO and PSO are coupled with the HYPE model to distribute a set of measures and compute the resulting TN reduction. The algorithms spatially distribute nine crop and subbasin-level mitigation measures under four categories. Both algorithms can successfully yield a discrete combination of measures to reduce long-term annual mean TN concentration. They achieved an 18.65% reduction, and their performance was on par with each other. This study has established the applicability of these bio-inspired optimization algorithms in successfully distributing the TN mitigation measures within the river basin.
Stakeholder involvement is a crucial aspect of IRBM. It ensures that researchers and policymakers are aware of the ground reality through large amounts of information collected from the stakeholder. Including stakeholders in policy planning and decision-making legitimizes the decisions and eases their implementation. Therefore, a socio-hydrological framework is developed and tested in the Larqui river basin, Chile, based on a field survey to explore the conditions under which the farmers would implement or extend the width of vegetative filter strips (VFS) to prevent soil erosion. The framework consists of a behavioral, social model (extended Theory of Planned Behavior, TPB) and an agent-based model (developed in NetLogo) coupled with the results from the vegetative filter model (Vegetative Filter Strip Modeling System, VFSMOD-W). The results showed that the ABM corroborates with the survey results and the farmers are willing to extend the width of VFS as long as their utility stays positive. This framework can be used to develop tailor-made policies for river basins based on the conditions of the river basins and the stakeholders' requirements to motivate them to adopt sustainable practices.
It is vital to assess whether the proposed management plans achieve the expected results for the river basin and if the stakeholders will accept and implement them. The assessment via simulation tools ensures effective implementation and realization of the target stipulated by the decision-makers. In this regard, this dissertation introduces the application of bio-inspired optimization techniques in the field of IRBM. The successful discrete combinatorial optimization in terms of the spatial distribution of mitigation measures by ACO and PSO and the novel socio-hydrological framework using ABM prove the forte and diverse applicability of bio-inspired optimization algorithms
2020 GREAT Day Program
SUNY Geneseo’s Fourteenth Annual GREAT Day.https://knightscholar.geneseo.edu/program-2007/1014/thumbnail.jp
Burmese pythons in Florida: A synthesis of biology, impacts, and management tools
Burmese pythons (Python molurus bivittatus) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive Burmese pythons. We describe existing control tools and review challenges to productive research, identifying key knowledge gaps that would improve future research and decision making for python control. (119 pp
Social behaviours in rat models of autism
Neurodevelopmental disorders (NDDs) manifest during early childhood and have
deleterious effects on development, leading to lifelong conditions affecting attention,
cognition, motor abilities, communication and social domains, often alongside
physical ailments such as gastrointestinal issues and epilepsy. With a worldwide
reported prevalence of around 1%, NDDs either directly or indirectly affect a large
proportion of the population.
Rodent models of monogenic forms of NDD provide a means for unravelling
mechanisms and developing targeted therapeutics for debilitating aspects of NDDs.
However, modelling social and emotional facets of NDDs such as autism spectrum
disorder (ASD) remains a challenge. The rat makes a good model species for the
social and emotional facets of NDDs as rats are highly social, experience a sensitive
period of social and emotional development, and exhibit a behavioural repertoire
that is flexible and sensitive to context. The aim of this thesis was to develop a welfarefriendly,
robust assay of socio-emotional phenotype in rat models of NDD.
Play behaviour appears to be a critical aspect of the developmental process in many
highly social species, including both rats and humans. Children develop social skills
and emotional regulation through playful peer interactions. For individuals with
NDDs, including ASD, social challenges often emerge from a very young age and
impair playful interactions with peers. In juvenile rats, play experience is crucial for
social, emotional, and sensorimotor development. Therefore, disruptions in social
and emotional function in rat models of NDD may be observable in juvenile play
behaviour. While juvenile play has been well-characterised in wild-type (WT) rats, it
has not yet been thoroughly investigated in rat models of NDDs.
Some aspects of rat social play can be mimicked during playful interactions with
humans in which the rat is ‘pinned’ by gently flipping onto the back and tickling using
fine-scale tickle movements of the fingers on the ventral surface. During tickle, rats
produce ultrasonic vocalisations (USVs) indicative of a positive affective state which
can be used as a proxy measure of tickle responsiveness. Number of successful pin
and tickle events per tickle session was used as a behavioural measure of
responsiveness as rats were only pinned if they engaged with the experimenter’s
hand. As an assay of social responsiveness, I investigated behavioural and USV
responses to tickle in three different rat models of NDD associated with ASD: Fragile
X Syndrome, SYGNAP1 haploinsufficiency, and CDKL5 Deficiency Disorder.
Tickle response varied between models of NDD. Tickle response in the Fragile X
Syndrome model (Fmr1-/y) was very similar to WT littermate controls, with high rates
of both USVs and pin/tickle events during tickle sessions in both genotypes. In
contrast, for models of SYNGAP1 haploinsufficiency (Syngap1+/DGAP and Syngap1+/-),
the tickle protocol was almost impossible to carry out due to climbing behaviour by
the SYNGAP1 model rats, and very few USVs were emitted during tickle sessions.
WTs were receptive to tickle and emitted USVs at high rates during tickle sessions. In
the CDKL5 Deficiency Disorder model (Cdkl5-/y), both WT and Cdkl5-/y rats emitted
very few USVs, and behavioural and USV responses were more variable in Cdkl5-/y
than in WTs. Because the tickle paradigm involves habituation to a novel environment
and experimenter handling, reduced tickle responsiveness may not be indicative of
playfulness or social responsiveness in general but could instead reflect an
impairment in habituation, since tickle response is highly sensitive to emotional state.
To address this possibility, I developed a novel paradigm which allows all
experimental manipulations and observations to be carried out in a spatially complex
home environment, minimising handling and exposure to novel experimental
environments. Play behaviour was observed for the first 2 hours of the dark phase
over a 4-week period following three experimental conditions: 24hr isolation, a
negative control condition, and an undisturbed condition.
In WT rats, brief isolation reliably elicits a transient increase in play, termed the
rebound effect. As isolation is stressful, the rebound effect is thought to reflect an
immediate benefit of play as a behavioural stress-reduction mechanism. I
hypothesised that Cdkl5-/y rats may not use this behavioural strategy to reduce stress
following isolation, or alternatively, that they would not find social isolation as stressful
as their WT littermates. I predicted that Cdkl5-/y pairs would show less of a play
rebound effect than their WT littermates.
Unexpectedly, my results suggest that both WT and Cdkl5-/y pairs exhibit the
expected rebound effect in response to brief (24hr) isolation. Further characterisation
of play behaviour revealed that pairs of Cdkl5-/y rats engage in more frequent play
bouts, but play for a similar amount of time as WT littermate pairs, and these
parameters were affected differently by treatment condition in WT and Cdkl5-/y pairs.
Detailed snapshot and longitudinal analysis of play behaviour indicates that the
temporal dynamics and sequencing of play in Cdkl5-/y pairs differs from WT
littermates, and that the developmental trajectory of play behaviour may diverge from
WT in Cdkl5-/y pairs.
Overall, this thesis provides evidence that rat models of NDD behave differently in
social contexts than WT animals and highlights the benefit of ethologically relevant
outcome measures and minimally invasive test environments for uncovering subtle
social and emotional phenotypes in rat models of NDD
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