Publications

The wide range of potential real-world applications (e.g. smart city, traffic management, crash detection) for the Multi- Camera Vehicle Tracking (MCVT) problem makes it a worthwhile research topic in the computer vision field.

In general, there are two approaches to address the MCVT problem: the global approach, which processes detections to create unified tracks directly, and the more commonly used two-step hierarchical approach, which involves separate stages for intracamera and inter-camera tracking. Typically, the two-step hierarchical MCVT approach can be further divided into four modules: object detection, feature extraction, single camera tracking and multi camera tracking. Each module plays a distinct role in enhancing the overall effectiveness of MCVT solutions. 

To date, there has only been limited research thoroughly examining how these modules individually affect the overall tracking performance. This paper presents an ablation study on the MCVT problem as a case study using the CityFlow V2 dataset. Using a benchmark MCVT framework, various state-of-art algorithms for each module have been implemented back-to-back to assess the impact of these algorithms. The effectiveness of these algorithms is assessed through two key metrics: IDF1 score performance and computational complexity. 

The study provides a comprehensive comparison study to understand the contributions of different algorithms in each module. Among all those modules, automatically generated spatial-temporal constraints maintains the computational efficiency while also contribute a lot on IDF1 score performance which could be the focusing point for future research on real-time real-world application

Structural batteries utilise the bifunctionality of carbon fibres to act as a load-bearing structure, but also as a conductive current collector for a battery electrode. Lithium-ion transport during the cycling of structural battery cathodes coated with different morphologies is investigated using Iron X-Ray Absorption Near Edge Spectroscopy (Fe XANES) and correlated to electrochemical performance.

Two contrasting morphologies were produced using slurry coating and electrophoretic deposition (EPD) of lithium-iron phosphate (LFP) onto continuous carbon fibres. The ability to study the different structural battery cathode morphologies operando allows for a comparative analysis of their impact on cycling performance. The EPD-coated fibres exhibited a more homogeneous, thinner coating around the fibre compared to the thick, one-sided coating produced using slurry coating. Despite a lower initial capacity and 30 % lithium re-intercalation loss in the first cycle, EPD-coated fibres exhibited more stable capacity retention over time compared to slurry-coated counterparts. Electrochemical Impedance Spectroscopy (EIS) revealed initially high ionic resistance for the EPD-coated fibres, but a larger increase in resistance in the slurry coated electrodes over multiple cycles. 

This study demonstrated an innovative and novel method of analysing in greater detail, the cycling ability of the coated cathode material on carbon fibres using synchrotron radiation.

Multi-Target Multi-Camera Tracking (MTMCT) has broad applications and forms the basis for numerous future city-wide systems (e.g. traffic management, crash detection, etc.). However, the challenge of matching vehicle trajectories across different cameras based solely on feature extraction poses significant difficulties. This article introduces an innovative multi-camera vehicle tracking system that utilizes a self-supervised camera link model. In contrast to related works that rely on manual spatial-temporal annotations, our model automatically extracts crucial multi-camera relationships for vehicle matching.

The camera link is established through a pre-matching process that evaluates feature similarities, pair numbers, and time variance for high-quality tracks. This process calculates the probability of spatial linkage for all camera combinations, selecting the highest scoring pairs to create camera links. 

Our approach significantly improves deployment times by eliminating the need for human annotation, offering substantial improvements in efficiency and cost-effectiveness when it comes to real-world application. This pairing process supports cross camera matching by setting spatial-temporal constraints, reducing the searching space for potential vehicle matches.

According to our experimental results, the proposed method achieves a new state-of-the-art among automatic camera-link based methods in CityFlow V2 benchmarks with 61.07% IDF1 Score.

Ambitious national targets for reducing transport emissions require effective policies that disturb entrenched unsustainable travel behaviours, in particular car use. One approach policymakers can adopt is to leverage transport environment disruptions as opportunities to destabilise habits and facilitate shifts in travel behaviour.

A framework consisting of four key dimensions of disruptions (plannedness, scale, frequency, and duration) is presented. The current study investigates whether UK transport policymakers and practitioners currently recognise opportunities in transport environment disruptions across these dimensions, and the factors facilitating or preventing this approach. 

Through qualitative analysis of in-depth interviews with 23 transport practitioners from various UK transport organisations and key strategic documents, the findings reveal that while practitioners acknowledge the potential of disruptions in the transport environment to foster behavioural shifts to some extent, general approaches are limited in their conceptualisations of disruptions.

 Recommendations emphasise the need for comprehensive strategies that leverage disruptions driven by bold political leadership to overcome car dependency and achieve sustainable transport goals.

The decarbonisation of the transport sector is central to the UK's net-zero strategy. This study evaluates the economic viability of depot-charged single-decker electric bus fleets by integrating vehicle, crew, and charging scheduling into a total cost of ownership analysis.

Our results indicate that today's electrified bus fleets are roughly cost comparable to their traditional diesel counterparts. However, the cost disparity varies depending on the timetabling scenario, such that smaller operations continue to require subsidisation. 

We conclude that further battery price reductions and a more targeted subsidy system are critical to bridging the cost gap between the two propulsion technologies in a way which maximises taxpayers' value for money.

Reducing the particle size of the metal–organic frameworks (MOFs) MIL-68(In) and ZIF-8 leads to increased adsorption of volatile semiochemical guests. Opposing trends were observed in release dynamics, with the release rate of isobutyl acetate increasing with particle size for MIL-68(In) and decreasing for ZIF-8, which can be attributed to the lower diffusion barriers through channels in comparison to moving between discrete pores.

The turbocharging of hydrogen fuel cell systems (FCSs) has recently become a prominent research area, aiming to improve FCS efficiency to help decarbonise the energy and transport sectors. This work compares the performance of an electrically assisted variable-geometry turbocharger (VGT) with a fixed-geometry turbocharger (FGT) by optimising both the sizing of the components and their operating points, ensuring both designs are compared at their respective peak performance.

A MATLAB-Simulink reduced-order model is used first to identify the most efficient components that match the fuel cell air path requirements. Maps representing the compressor and turbines are then evaluated in a 1D flow model to optimise cathode pressure and stoichiometry operating targets for net system efficiency, using an accelerated genetic algorithm (A-GA). Good agreement was observed between the two models’ trends with a less than 10.5% difference between their normalised e-motor power across all operating points. 

Under optimised conditions, the VGT showed a less than 0.25% increase in fuel cell system efficiency compared to the use of an FGT. However, a sensitivity study demonstrates significantly lower sensitivity when operating at non-ideal flows and pressures for the VGT when compared to the FGT, suggesting that VGTs may provide a higher level of tolerance under variable environmental conditions such as ambient temperature, humidity, and transient loading. 

Overall, it is concluded that the efficiency benefits of VGT are marginal, and therefore not necessarily significant enough to justify the additional cost and complexity that they introduce.

Prospective life cycle assessment (pLCA) using scenarios from integrated assessment models (IAMs) can explore future environmental impacts. However, results are sensitive to the IAM used and only scenarios from two IAMs – REMIND and IMAGE – have been soft-coupled with pLCA using Premise.

Here, we establish a new linkage to a third IAM - TIAM-UCL - which diversifies available IAM scenarios and strengthens potential conclusions from pLCA. Over 200 variables across 16 global regions were linked to over 300 LCA processes, representing future technological changes across seven major sectors, including electricity, fuels, and steel.

We analyse the future life-cycle impacts of the global electricity mix per kWh delivered to low-voltage consumers using TIAM-UCL scenarios, ecoinvent v3.9.1, and the EF 3.1 impact assessment method. In 1.5–2.0 °C futures, projected reductions in climate change impact from fossil-fuel phase-out have substantial co-benefits in ten categories, such as acidification reducing over 90 % by 2050. Trade-offs are found in five categories, such as critical material shortages. Comparing pLCA results based on all three IAM models showed consistent reductions in climate change impact to meet 1.5–2.0 °C futures.

However, differences in other impact category results arose due to variations in low-carbon technologies deployed, such as IMAGE showing smaller environmental co-benefits due to preferences for CCS-fitted fossil generation, while REMIND had increased land use from greater solar uptake.

Therefore, it is essential to consider the influence of IAM choice when interpreting pLCA outcomes. The addition of TIAM-UCL, now available in Premise, will enable more robust modelling of prospective environmental impacts.