N. Yorke-Smith
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123 records found
1
Global-Local Attention vs Graph Neural Networks in the Reinforcement Learning Approach for the Dynamic Berth Allocation Problem
Bridging the Optimality Gap in Dynamic Berth Allocation Problem via Global-Local Attention
Efficient Production Scheduling Under Uncertainty
Combining Constraint Programming, Heuristics, and Monte Carlo Simulations in Industrial Scheduling
To tackle this, a comprehensive scheduling framework was developed. First, a heuristic split-schedule-join paradigm is introduced to handle lot sizing, eliminating combinatorial explosion while preserving order-splitting flexibility. Second, a modular Constraint Programming (CP) model is formulated to optimise batch assignments and sequencing using a multi-step lexicographic approach prioritising lateness, transition costs, and total completion time. To ensure practical industrial viability and scalability, a custom greedy constructive heuristic is integrated as a warm-start mechanism for the CP solver. Finally, operational uncertainty is addressed through a Monte Carlo simulation engine that models historical duration deviations, forecasting schedule robustness and quantifying the value of reactive rescheduling.
Empirical evaluation across diverse static and disrupted instances demonstrates the framework's efficacy. The CP model assisted by the greedy warm-start (CP-WS) guarantees 100% feasibility on highly constrained instances, accelerates early convergence by a factor of 2.3, and reduces lateness and transition costs by approximately 50% compared to the greedy baseline. Furthermore, stochastic experiments reveal that while minor disruptions are best absorbed by existing schedule structures, targeted reactive rescheduling under severe delays recovers an average of over 800 minutes of accumulated lateness. By combining constraint programming, heuristic acceleration, and simulation-based risk analysis, this thesis transforms OccaSee into a dynamic decision support system capable of robust industrial scheduling. ...
To tackle this, a comprehensive scheduling framework was developed. First, a heuristic split-schedule-join paradigm is introduced to handle lot sizing, eliminating combinatorial explosion while preserving order-splitting flexibility. Second, a modular Constraint Programming (CP) model is formulated to optimise batch assignments and sequencing using a multi-step lexicographic approach prioritising lateness, transition costs, and total completion time. To ensure practical industrial viability and scalability, a custom greedy constructive heuristic is integrated as a warm-start mechanism for the CP solver. Finally, operational uncertainty is addressed through a Monte Carlo simulation engine that models historical duration deviations, forecasting schedule robustness and quantifying the value of reactive rescheduling.
Empirical evaluation across diverse static and disrupted instances demonstrates the framework's efficacy. The CP model assisted by the greedy warm-start (CP-WS) guarantees 100% feasibility on highly constrained instances, accelerates early convergence by a factor of 2.3, and reduces lateness and transition costs by approximately 50% compared to the greedy baseline. Furthermore, stochastic experiments reveal that while minor disruptions are best absorbed by existing schedule structures, targeted reactive rescheduling under severe delays recovers an average of over 800 minutes of accumulated lateness. By combining constraint programming, heuristic acceleration, and simulation-based risk analysis, this thesis transforms OccaSee into a dynamic decision support system capable of robust industrial scheduling.
Comparing Encoder Architectures for the Discrete Berth Allocation Problem
Testing a pure attention transformer mechanism as an alternative to the GAT encoder a Reinforcement Learning agent uses to solve the Discrete Berth Allocation Problem
encoder in a reinforcement learning framework with a direct attention mechanism to solve the Dynamic Discrete Berth Allocation Problem (DDBAP): the challenge of assigning ships to specific docking spots over time. We tested two alternative designs, a Pure Attention Transformer and a topology-aware Edge-Transformer, against a baseline Graph Attention Network (GAT) using 27 simulated shipping scenarios. On average, the baseline GNN performed relatively better overall, scoring an average cost of 646.58 compared to 650.72 for the Edge-Transformer and 658.63 for the Pure Transformer. However, the best choice depends entirely on the size of the problem. The GNN works best in low-traffic situations with plenty of available berths because it ignores irrelevant background information. In contrast, when the port gets highly congested, such as 120 ships competing for just 5 berths, the global attention mechanism performs much better because it can anticipate long-term queue delays. Finally, while the attention-based models take significantly longer to train over 30,000 samples, they both process decisions in less than a second during live testing. This makes them highly practical for real-time maritime scheduling. ...
encoder in a reinforcement learning framework with a direct attention mechanism to solve the Dynamic Discrete Berth Allocation Problem (DDBAP): the challenge of assigning ships to specific docking spots over time. We tested two alternative designs, a Pure Attention Transformer and a topology-aware Edge-Transformer, against a baseline Graph Attention Network (GAT) using 27 simulated shipping scenarios. On average, the baseline GNN performed relatively better overall, scoring an average cost of 646.58 compared to 650.72 for the Edge-Transformer and 658.63 for the Pure Transformer. However, the best choice depends entirely on the size of the problem. The GNN works best in low-traffic situations with plenty of available berths because it ignores irrelevant background information. In contrast, when the port gets highly congested, such as 120 ships competing for just 5 berths, the global attention mechanism performs much better because it can anticipate long-term queue delays. Finally, while the attention-based models take significantly longer to train over 30,000 samples, they both process decisions in less than a second during live testing. This makes them highly practical for real-time maritime scheduling.
In this thesis, we study how the communication reliability of Earth--Moon satellite constellations can be modelled and evaluated. We represent the communication network as a probabilistic graph, in which vertices correspond to satellites and edges correspond to communication links. We consider two reliability metrics: the probability that communication exists between Earth and Moon ground-connected satellites and the probability that the entire network is connected. We also study hop-constrained variants of these metrics, as in quantum communication the number of relay hops is limited.
To evaluate the communication reliability of Earth-Moon satellite constellations, we use projected weighted model counting. Starting from Walker constellations around both the Earth and the Moon, we propagate satellite positions over time. At selected discrete timestamps, we build probabilistic networks to represent the constellation at that point in time. We then encode communication properties as propositional formulas and apply projected weighted model counting to compute reliability. We compare two encodings: one based on reachability, adapted from existing work, and one that explicitly models communication paths.
We evaluate the proposed approach on multiple constellation configurations and timestamps. The experiments provide insights into the factors affecting communication reliability and the computational performance of the two encodings. The results show that projected weighted model counting can be used to evaluate the reliability of dynamic Earth--Moon satellite communication networks, while also highlighting scalability challenges for larger problem instances.
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In this thesis, we study how the communication reliability of Earth--Moon satellite constellations can be modelled and evaluated. We represent the communication network as a probabilistic graph, in which vertices correspond to satellites and edges correspond to communication links. We consider two reliability metrics: the probability that communication exists between Earth and Moon ground-connected satellites and the probability that the entire network is connected. We also study hop-constrained variants of these metrics, as in quantum communication the number of relay hops is limited.
To evaluate the communication reliability of Earth-Moon satellite constellations, we use projected weighted model counting. Starting from Walker constellations around both the Earth and the Moon, we propagate satellite positions over time. At selected discrete timestamps, we build probabilistic networks to represent the constellation at that point in time. We then encode communication properties as propositional formulas and apply projected weighted model counting to compute reliability. We compare two encodings: one based on reachability, adapted from existing work, and one that explicitly models communication paths.
We evaluate the proposed approach on multiple constellation configurations and timestamps. The experiments provide insights into the factors affecting communication reliability and the computational performance of the two encodings. The results show that projected weighted model counting can be used to evaluate the reliability of dynamic Earth--Moon satellite communication networks, while also highlighting scalability challenges for larger problem instances.
The Robustness of the GNN approach in application of different data-generation method
How robust is the GNN approach when applied to instances generated using different data-generation methods or distributions?
Reinforcement Learning for the Discrete Dynamic Berth Allocation Problem
Evaluating a trained Discrete Dynamic Berth Allocation model on Berth breakdowns
Beyond Static Parameters: Adaptive Simulated Annealing in Practice
A case study on environmentally-aware lockage scheduling for the North Sea Locks
Anomaly Detection in Geostationary Satellites
Unsupervised, Satellite-Agnostic Error Detection & Localisation
As Eugene Wigner showed in 1939 for the Poincaré algebra, fundamental particles can be classified using symmetry algebras. In a universe including gravity, the Poincaré algebra cannot be the correct symmetry algebra, as this is the symmetry algebra for flat space. Instead, one should consider a symmetry algebra of asymptotic symmetries, which preserve only the asymptotic structure of gravity. Many of these asymptotic symmetries are not physically useful and are therefore considered “trivial.”
In this thesis, we give a new quantum definition of trivial symmetries, namely that a symmetry is trivial if it does not change which fundamental particles are found in a classification. We then specialize to three-dimensional asymptotically Anti-de-Sitter space. To calculate which symmetries are trivial, we first determine the second cohomology group of the asymptotic symmetries. Using the second cohomology group, it is then found that the useful asymptotic symmetry algebra is given by w⊕w⊕Rw \oplus w \oplus \mathbb{R}w⊕w⊕R, where www is the Witt algebra (centerless Virasoro) algebra, whereas the standard definition of trivial symmetry gives w⊕ww \oplus ww⊕w as the useful symmetry algebra. The extra factor of R\mathbb{R}R is interpreted as a kind of center-of-mass momentum.
Improving Inland and Short-Sea Vessel Scheduling using Constraint Optimization
A Google OR-Tools Implementation for a Container Vessel Planning System
This thesis presents Orion, a constraint-based optimization solver built on the Google OR-Tools Routing Library, designed to automate and improve this vessel scheduling process. The problem is formulated using Constraint Programming, which allows complex business rules to be expressed as logical predicates rather than linearized inequalities. The solver pipeline includes a data preprocessing stage that aggregates individual container orders into compound orders, reducing problem size by approximately 90\% while preserving solution quality.
The evaluation follows a three-phase methodology. First, a feasibility analysis filters 14 construction heuristics down to two viable candidates: Local Cheapest Insertion and Parallel Cheapest Insertion. Second, a parameter tuning phase identifies Local Cheapest Insertion combined with Tabu Search as the best-performing configuration, achieving an Average Relative Percentage Deviation of 2.72\% across all scenarios. Third, a benchmarking phase compares Orion against human planners and the company's existing Simulated Annealing solver (Baseline SA) on six real-world scenarios from three distinct logistics operators.
The results show that Orion achieves travel cost reductions of 6.7\% to 32.8\% compared to human planners on five of six scenarios and outperforms Baseline SA's average result on five of six scenarios. A key structural advantage is determinism: Orion produces identical results across repeated runs, whereas Baseline SA exhibits variance of up to 37.5\% between its best and worst runs. Convergence analysis indicates that 96--99.97\% of objective improvement occurs within the first 30 seconds, making a 5-minute time budget sufficient for operational use.
The thesis concludes with recommendations for production deployment and identifies future research directions, including dynamic water level constraints, improved rolling-horizon replanning, custom fleet reduction operators, and hub-based consolidation strategies.
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This thesis presents Orion, a constraint-based optimization solver built on the Google OR-Tools Routing Library, designed to automate and improve this vessel scheduling process. The problem is formulated using Constraint Programming, which allows complex business rules to be expressed as logical predicates rather than linearized inequalities. The solver pipeline includes a data preprocessing stage that aggregates individual container orders into compound orders, reducing problem size by approximately 90\% while preserving solution quality.
The evaluation follows a three-phase methodology. First, a feasibility analysis filters 14 construction heuristics down to two viable candidates: Local Cheapest Insertion and Parallel Cheapest Insertion. Second, a parameter tuning phase identifies Local Cheapest Insertion combined with Tabu Search as the best-performing configuration, achieving an Average Relative Percentage Deviation of 2.72\% across all scenarios. Third, a benchmarking phase compares Orion against human planners and the company's existing Simulated Annealing solver (Baseline SA) on six real-world scenarios from three distinct logistics operators.
The results show that Orion achieves travel cost reductions of 6.7\% to 32.8\% compared to human planners on five of six scenarios and outperforms Baseline SA's average result on five of six scenarios. A key structural advantage is determinism: Orion produces identical results across repeated runs, whereas Baseline SA exhibits variance of up to 37.5\% between its best and worst runs. Convergence analysis indicates that 96--99.97\% of objective improvement occurs within the first 30 seconds, making a 5-minute time budget sufficient for operational use.
The thesis concludes with recommendations for production deployment and identifies future research directions, including dynamic water level constraints, improved rolling-horizon replanning, custom fleet reduction operators, and hub-based consolidation strategies.
Uncertainty quantification is a central mechanism in such efficient exploration methods. Provided with an estimate of how certain the agent is about the outcome of an action, it can intelligently weigh whether it is worth exploring. The Bayesian paradigm is one method to quantify uncertainty in machine learning. It models the uncertainty with a probability distributions over models, specifying how likely a model is based on the data the agent has collected.
We adopt a Bayesian point of view in model-free reinforcement learning, and develop a deeper understanding on when Bayesian reinforcement learning methods can be expected to work well and challenges that remain. To this end, in Chapter 2 we propose training ensembles through Sequential Monte Carlo, obtaining a sample from the posterior distribution of a deep Q-learning agent. We observe that agents are able to perform directed exploration, although not necessarily more efficiently than standard ensembles in every environment. Furthermore, in Chapter 3 we theoretically analyze existing Bayesian Deep model-Free Reinforcement Learning methods, and unify them into a single theoretical framework we call Epistemic Bellman Operators. We prove that these operators are contractions, establishing convergence of derived algorithms in a simplified setting. Finally, in Chapter 4 we analyze the likelihood and prior assumptions
in existing Bayesian deep model-free reinforcement learning methods, and find through statistical tests that the standard likelihood assumptions are violated on every benchmark we tested. We also find that we can improve performance of Bayesian model free reinforcement learning methods by picking different priors based on empirical data from unrelated tasks, which transfer to new environments.
This dissertation establishes several desirable properties of Bayesian Deep model free reinforcement learning, but also raises some key issues, most notably misspecification in Chapter 4. We hope our findings convince other Bayesian reinforcement learning researchers to give more attention to assumptions about priors and likelihoods. ...
Uncertainty quantification is a central mechanism in such efficient exploration methods. Provided with an estimate of how certain the agent is about the outcome of an action, it can intelligently weigh whether it is worth exploring. The Bayesian paradigm is one method to quantify uncertainty in machine learning. It models the uncertainty with a probability distributions over models, specifying how likely a model is based on the data the agent has collected.
We adopt a Bayesian point of view in model-free reinforcement learning, and develop a deeper understanding on when Bayesian reinforcement learning methods can be expected to work well and challenges that remain. To this end, in Chapter 2 we propose training ensembles through Sequential Monte Carlo, obtaining a sample from the posterior distribution of a deep Q-learning agent. We observe that agents are able to perform directed exploration, although not necessarily more efficiently than standard ensembles in every environment. Furthermore, in Chapter 3 we theoretically analyze existing Bayesian Deep model-Free Reinforcement Learning methods, and unify them into a single theoretical framework we call Epistemic Bellman Operators. We prove that these operators are contractions, establishing convergence of derived algorithms in a simplified setting. Finally, in Chapter 4 we analyze the likelihood and prior assumptions
in existing Bayesian deep model-free reinforcement learning methods, and find through statistical tests that the standard likelihood assumptions are violated on every benchmark we tested. We also find that we can improve performance of Bayesian model free reinforcement learning methods by picking different priors based on empirical data from unrelated tasks, which transfer to new environments.
This dissertation establishes several desirable properties of Bayesian Deep model free reinforcement learning, but also raises some key issues, most notably misspecification in Chapter 4. We hope our findings convince other Bayesian reinforcement learning researchers to give more attention to assumptions about priors and likelihoods.
Data-Driven and Robust Predictive Control and Optimization
With Applications to Building Energy Management
• MPC designs for building energy management to enable energy-flexible DSM and improve environmental sustainability (Chapters 2–4).
• data-driven RO designs and algorithmic solutions for linear models to reduce conservatism and improve computational efficiency (Chapters 5 & 6).
• a distributionally robust MPC design for constrained linear systems to robustify control performance against additive model uncertainties and disturbances (Chapter 7). ...
• MPC designs for building energy management to enable energy-flexible DSM and improve environmental sustainability (Chapters 2–4).
• data-driven RO designs and algorithmic solutions for linear models to reduce conservatism and improve computational efficiency (Chapters 5 & 6).
• a distributionally robust MPC design for constrained linear systems to robustify control performance against additive model uncertainties and disturbances (Chapter 7).
Optimising Discrete Problems
Decision Diagrams and Context-Aware Heuristics
In Part I of this dissertation, we consider the problem of scheduling in manufacturing systems. This popular discrete optimisation problem has been studied extensively; however, advancements in modern manufacturing systems present new challenges and opportunities. A major driver of the changes in manufacturing systems is the integration of the physical processes with computation, networking, and automated control capabilities. Thus, the domain of activities that can directly be decided upon and actuated from software has expanded. We look at one such activity in Chapter 3 namely,
sequence-dependent maintenance and propose solution methods that directly integrate maintenance and production planning.
Part II of this thesis looks into decision diagrams as a solution method for discrete optimisation problems. Decision diagrams have existed since the 1950s and were originally introduced as a means to represent boolean functions. Since then they have been used in different fields such as in circuit verification, knowledge representation, and most recently, operations research. While decision diagrams have already been shown to be very promising methods for solving optimisation problems, we push the field forward as follows. In Chapter 5, we propose a decision diagram model for the kind of scheduling problems tackled in Part I of this thesis. We further perform a comparative study of the consequences of heuristic decisions made during the decision diagram compilation process in Chapter 6 and integrate reinforcement learning with decision-diagram-based branch-and-bound in Chapter 7. In Chapter 8 we go further into considering uncertainty in optimisation problems. We focus on the paradigm of finding the best solution while accepting some level of risk, i.e., chance constrained optimisation and present a chance constrained decision diagram formulation. We further provide theoretical guarantees for instances with normally distributed variables.
The contributions of this thesis cover different aspects of solving discrete optimisation problems with a focus on scheduling and logistic applications. The hope is that these advances further the adoption of state of the art research in solving optimisation problems in real-world contexts. ...
In Part I of this dissertation, we consider the problem of scheduling in manufacturing systems. This popular discrete optimisation problem has been studied extensively; however, advancements in modern manufacturing systems present new challenges and opportunities. A major driver of the changes in manufacturing systems is the integration of the physical processes with computation, networking, and automated control capabilities. Thus, the domain of activities that can directly be decided upon and actuated from software has expanded. We look at one such activity in Chapter 3 namely,
sequence-dependent maintenance and propose solution methods that directly integrate maintenance and production planning.
Part II of this thesis looks into decision diagrams as a solution method for discrete optimisation problems. Decision diagrams have existed since the 1950s and were originally introduced as a means to represent boolean functions. Since then they have been used in different fields such as in circuit verification, knowledge representation, and most recently, operations research. While decision diagrams have already been shown to be very promising methods for solving optimisation problems, we push the field forward as follows. In Chapter 5, we propose a decision diagram model for the kind of scheduling problems tackled in Part I of this thesis. We further perform a comparative study of the consequences of heuristic decisions made during the decision diagram compilation process in Chapter 6 and integrate reinforcement learning with decision-diagram-based branch-and-bound in Chapter 7. In Chapter 8 we go further into considering uncertainty in optimisation problems. We focus on the paradigm of finding the best solution while accepting some level of risk, i.e., chance constrained optimisation and present a chance constrained decision diagram formulation. We further provide theoretical guarantees for instances with normally distributed variables.
The contributions of this thesis cover different aspects of solving discrete optimisation problems with a focus on scheduling and logistic applications. The hope is that these advances further the adoption of state of the art research in solving optimisation problems in real-world contexts.
In light of the potentially enormous impact of bugs, it is important that we can trust a type system to be succesful in preventing errors. A key property of type systems that reflects this criterium is type soundness, which establishes that “well-typed programs cannot go wrong”. That is, programs that are deemed safe by the type system should not exhibit certain wrong behaviour when executed. To gain trust in a type system’s ability to prevent errors, we can give a formal system of both a language’s type system and semantics, and mathematically verify that the type system is sound with respect to the defined semantics. While this provides airtight evidence that a type system is succesful in ruling out certain mistakes, the formal specification and verification of programming languages requires a formidable amount of time and expertise on behalf of the language designer, and is therefore infeasible in most cases.... ...
In light of the potentially enormous impact of bugs, it is important that we can trust a type system to be succesful in preventing errors. A key property of type systems that reflects this criterium is type soundness, which establishes that “well-typed programs cannot go wrong”. That is, programs that are deemed safe by the type system should not exhibit certain wrong behaviour when executed. To gain trust in a type system’s ability to prevent errors, we can give a formal system of both a language’s type system and semantics, and mathematically verify that the type system is sound with respect to the defined semantics. While this provides airtight evidence that a type system is succesful in ruling out certain mistakes, the formal specification and verification of programming languages requires a formidable amount of time and expertise on behalf of the language designer, and is therefore infeasible in most cases....
Uncertainty Based Exploration in Reinforcement Learning
Analyzing the Robustness of Bayesian Deep Q-Networks
exploration, while other hyperparameters such as batch size also impact performance to varying degrees. These findings suggest BDQN is a promising strategy for complex tasks requiring persistent exploration, though it introduces additional tuning complexity. ...
exploration, while other hyperparameters such as batch size also impact performance to varying degrees. These findings suggest BDQN is a promising strategy for complex tasks requiring persistent exploration, though it introduces additional tuning complexity.
Heuristic Optimization of Amazon Redshift Table Configurations
Focusing on Distribution Style, Sort Keys and Column Encodings in Amazon Redshift
The study addresses four research questions examining individual parameter optimization strategies and their integrated effects on system performance. The experimental evaluation employs two datasets: a primary table containing 300 million data records across 23 columns where optimization is performed, and a secondary join table with 117.5 million data records across 12 columns that remains unchanged. Scale-dependent analysis is conducted using subsets of 10 million and 100 million data records selected from the primary dataset to enable controlled comparison across different data volumes.
Key findings demonstrate that table configuration optimization in Amazon Redshift exhibits pronounced scale-dependent performance characteristics across the experimental datasets, with three distinct performance regimes identified: a small-scale regime (10M data records) characterized by query-type dependent optimization effectiveness, a medium-scale regime (100M data records) showing optimization trade-off transitions, and a large-scale regime (300M data records) dominated by I/O and storage optimizations. The research reveals mixed optimization outcomes, with performance improvements ranging from 21 percent CPU reduction at small scales to 62 percent I/O improvement at large scales, while demonstrating that optimization strategies effective at one scale can become counterproductive at another. Overall, the framework shows variable success in parameter selection for distribution style, sort key and encoding selection.
The research identifies fundamental challenges in optimizing Amazon Redshift table configurations where internal algorithms remain opaque and optimization benefits exhibit non-linear scaling patterns across the tested different data volumes. While the framework provides valuable insights into scale-dependent optimization patterns, the mixed results highlight the complexity of achieving consistent performance improvements across different scales and query types. These findings challenge assumptions about uniform optimization benefits and emphasize the need for empirical validation approaches in cloud database optimization, providing practical insights for database administrators and theoretical foundations for developing adaptive optimization systems. ...
The study addresses four research questions examining individual parameter optimization strategies and their integrated effects on system performance. The experimental evaluation employs two datasets: a primary table containing 300 million data records across 23 columns where optimization is performed, and a secondary join table with 117.5 million data records across 12 columns that remains unchanged. Scale-dependent analysis is conducted using subsets of 10 million and 100 million data records selected from the primary dataset to enable controlled comparison across different data volumes.
Key findings demonstrate that table configuration optimization in Amazon Redshift exhibits pronounced scale-dependent performance characteristics across the experimental datasets, with three distinct performance regimes identified: a small-scale regime (10M data records) characterized by query-type dependent optimization effectiveness, a medium-scale regime (100M data records) showing optimization trade-off transitions, and a large-scale regime (300M data records) dominated by I/O and storage optimizations. The research reveals mixed optimization outcomes, with performance improvements ranging from 21 percent CPU reduction at small scales to 62 percent I/O improvement at large scales, while demonstrating that optimization strategies effective at one scale can become counterproductive at another. Overall, the framework shows variable success in parameter selection for distribution style, sort key and encoding selection.
The research identifies fundamental challenges in optimizing Amazon Redshift table configurations where internal algorithms remain opaque and optimization benefits exhibit non-linear scaling patterns across the tested different data volumes. While the framework provides valuable insights into scale-dependent optimization patterns, the mixed results highlight the complexity of achieving consistent performance improvements across different scales and query types. These findings challenge assumptions about uniform optimization benefits and emphasize the need for empirical validation approaches in cloud database optimization, providing practical insights for database administrators and theoretical foundations for developing adaptive optimization systems.
Algorithms for the Sharing Economy
An Economic Modelling Perspective on Distributed Exchange
The central aim of this work is to develop and analyse an algorithmic economic model that more faithfully captures the dynamics of decentralised resource sharing — balancing fairness, efficiency, and resistance to manipulation, while retaining a useful level of abstraction.
In light of this purpose, the thesis performs a comparative theoretical analysis of centralised and distributed exchange mechanisms, and introduces a novel exchange market model that incorporates heterogeneous strategies, bounded rationality, and asynchronous timing. A series of numerical experiments evaluates the performance and robustness of different protocols under these features of sharing economies.
The results show that distributed, mixed-strategy protocols can achieve stable and desirable outcomes, however their success is sensitive to population diversity, limited information, and strategic behaviour. These findings highlight the importance of integrating behavioural aspects into protocol design, and provide insights towards building more robust models for the sharing economy. ...
The central aim of this work is to develop and analyse an algorithmic economic model that more faithfully captures the dynamics of decentralised resource sharing — balancing fairness, efficiency, and resistance to manipulation, while retaining a useful level of abstraction.
In light of this purpose, the thesis performs a comparative theoretical analysis of centralised and distributed exchange mechanisms, and introduces a novel exchange market model that incorporates heterogeneous strategies, bounded rationality, and asynchronous timing. A series of numerical experiments evaluates the performance and robustness of different protocols under these features of sharing economies.
The results show that distributed, mixed-strategy protocols can achieve stable and desirable outcomes, however their success is sensitive to population diversity, limited information, and strategic behaviour. These findings highlight the importance of integrating behavioural aspects into protocol design, and provide insights towards building more robust models for the sharing economy.