https://www.um.edu.mt/library/oar/handle/123456789/8336 2026-04-10T08:08:17Z 2026-04-10T08:08:17Z https://www.um.edu.mt/library/oar/handle/123456789/144338 2026-02-26T13:46:09Z 2025-01-01T00:00:00Z

Title: Towards the efficient adaptation of offline physically based methods for real-time rendering Abstract: Rendering physically accurate caustics in real-time remains a persistent challenge due to their complex light interactions and high-frequency features. This thesis presents a comprehensive exploration into adapting oìine physically based rendering techniques for real-time caustic synthesis on modern GPU architectures. Central to this work is CandelaDXR, a GPU-accelerated light tracer that employs novel importance sampling strategies to improve convergence speed and visual adelity for caustics. By generating dynamic probability distribution functions conditioned on scene geometry, camera parameters, and material properties, CandelaDXR prioritises specular interactions and focuses sampling eêorts on perceptually relevant regions. To support this system, two auxiliary tools were developed: Anvil, a modular visual debugging platform for rendering pipelines, and Forge, an evaluation framework designed to facilitate reproducible, cross-system comparisons. These tools provide both insight and rigour in diagnosing rendering artefacts and validating algorithmic improvements. Additionally, the thesis introduces a spectral denoising pipeline tailored to the distinct characteristics of caustic signals, demonstrating the eêectiveness of Fourier, wavelet and curvelet-based transforms in preserving detail while reducing noise. Quantitative results across multiple scenes and viewpoints reveal signiacant performance gains, noise reduction, and perceptual improvements in CandelaDXR over baseline methods. Collectively, this work contributes a uniaed architecture for real-time caustic rendering, debugging, and evaluation, offering practical advances in both rendering theory and implementation for real-time physically based graphics. Description: Ph.D.(Melit.)

2025-01-01T00:00:00Z Gatt, Cristina Micallef, Mark Bugeja, Mark https://www.um.edu.mt/library/oar/handle/123456789/143412 2026-02-03T13:54:00Z 2023-04-01T00:00:00Z

Title: Marco Polo - a tool for automated exploratory testing of previously unseen online stores Authors: Gatt, Cristina; Micallef, Mark; Bugeja, Mark Abstract: Online stores continue to increase in popularity with 2.3 billion people estimated to have shopped online during 2022. Whilst every online store is unique in its own right, the online shopping domain itself is quite constrained in terms of the type of functionality being offered. This begs the question as to why companies invest so much time, effort and money into developing complete test suites for their specific systems. In this paper, we argue that it would be more efficient for companies to leverage the abundant common ground between most systems in the domain such that they need only focus on features that make their product unique when it comes to allocating testing effort. We go on to present Marco Polo, an automated exploratory testing tool inspired by the renowned explorer and trader from the 13th century. Using behavioural cloning to train on expert traces from a sample of online stores, this tool is able to exploratory-test previously unseen websites whilst handling reactive websites and events such as cookie/GDPR consents. We discuss design decisions as well as challenges and opportunities for further development. A demo URL is also provided.

2023-04-01T00:00:00Z Aceto, Luca Achilleos, Antonis Anastasiadi, Elli Francalanza, Adrian Gorla, Daniele Wagemaker, Jana https://www.um.edu.mt/library/oar/handle/123456789/141715 2025-11-28T13:35:52Z 2025-01-01T00:00:00Z

Title: Centralized vs. decentralized monitors for hyperproperties Authors: Aceto, Luca; Achilleos, Antonis; Anastasiadi, Elli; Francalanza, Adrian; Gorla, Daniele; Wagemaker, Jana Abstract: This article focuses on the runtime verification of hyperproperties expressed in Hyper-recHML, an expressive yet simple logic for describing properties of sets of traces. To this end, we consider a simple language of monitors that observe sets of system executions and report verdicts w.r.t. a given Hyper-recHML formula. We first employ a unique omniscient monitor that centrally observes all system traces. Since centralized monitors are not ideal for distributed settings, we also provide a language for decentralized monitors, where each trace has a dedicated monitor; these monitors yield a unique verdict by communicating their observations to one another. For both the centralized and the decentralized settings, we provide a synthesis procedure that, given a formula, yields a monitor that is correct (i.e., sound and violation complete). A key step in proving the correctness of the synthesis for decentralized monitors is a result showing that, for each formula, the synthesized centralized monitor and its corresponding decentralized one are weakly bisimilar for a suitable notion of weak bisimulation.

2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/140356 2025-10-21T06:21:23Z 2018-11-01T00:00:00Z

Title: CSAW'18 computer science annual workshop Abstract: This is a collection of abstracts from the 2018 edition of the Computer Science Annual Workshop (CSAW'18), a research and work-in-progress workshop organised by the Department of Computer Science of the University of Malta. CSAW'18 was held at the Hilltop Gardens in Naxxar, Malta on the 30th November.

2018-11-01T00:00:00Z