https://www.um.edu.mt/library/oar/handle/123456789/2068 Sat, 25 Jul 2026 08:18:17 GMT 2026-07-25T08:18:17Z https://www.um.edu.mt/library/oar/handle/123456789/148120 Title: The development of a B-Train system for the CERN proton synchrotron booster Abstract: In particle accelerators, large electromagnets generate the perpendicular magnetic field that dictates the beam trajectory based on the Lorentz force law. Therefore, precise knowledge of the integrated dipole field produced by these accelerator-magnets is essential for transverse and longitudinal beam control. Consequently, machine operators rely on look-up tables, prediction models, or online measurement systems, called B-Trains, to acquire and distribute the magnetic dipole field in real-time. At the European Organization for Nuclear Research (CERN) accelerator complex, all synchrotrons have been fitted with a new standardised B-Train setup as part of a site-wide consolidation project. This so-called Field In REal-time STreaming from Online Reference-Magnets (FIRESTORM) system has been developed in-house to accommodate the various requirements of the six different machines. One such machine is the Proton Synchrotron Booster (PSB), which was constructed in the 1970s and has undergone several upgrades to meet the ever-increasing demand for higher energies. The most recent upgrade, which occurred in 2020, enabled the PSB to accelerate beams up to 2.0 GeV every 1.2 s. This thesis deals with the work involved in implementing the new B-Train setup for the main-bending-magnets of the PSB. The first part provides an overview of the new FIRESTORM system, detailing its architecture and the operating principle behind several components. The results of a metrological characterisation of its offline performance are also provided, including drift correction, gain calibration and frequency response, in addition to the overall latency of its distribution network. Furthermore, the FIRESTORM system underwent an online qualification campaign to compare its capabilities with the previous Legacy setup. The second part focuses on the calibration process of the induction-coils. It is well known that saturation of the yoke affects the longitudinal field profile of an acceleratormagnet and, by extension, the measurement accuracy. Therefore, this thesis presents a novel measurement method developed for measuring fast-pulsed magnetic fields using the Single Stretched Wire (SSW) system. Being the reference standard, the SSW is commonly used to measure steady-state magnetic fields with absolute precision. This new procedure expands the capabilities of the SSW setup, enabling accurate measurements of timevarying magnetic fields in addition to those at steady-state. Furthermore, this work also proposes a magnetic model that characterises the quasi-static and dynamic responses of iron-dominated bending-magnets. The model presents a method for predicting eddy-currents as a summation of response-functions. Using the PSB main-bending-magnet as a test case, the model successfully replicates the transfer-function with a relative accuracy of less than 200 ppm. Description: Ph.D.(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/148120 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/147770 Title: Runtime verification and AI : addressing pragmatic regulatory challenges Authors: Colombo, Christian; Pace, Gordon; Seychell, Dylan Abstract: The deployment of AI-driven solutions to increasingly complex tasks with real-world impact raises various challenges in the area of verification. Using the case study of an AI-assisted litter detection being developed for rural areas in Malta, this paper highlights the multi-faceted nature of the risks involved concerning: data issues, functionality correctness, safety concerns, and legal considerations. We place particular focus on the last of these: regulatory challenges. Drawing inspiration from related works, considering applicable Maltese technology guidelines and EU legislation, against the backdrop of the challenges presented in the case study, the proposed runtime verification architecture brings the pieces together in a comprehensive and pragmatic manner. [excerpt] Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/147770 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/147766 Title: Interest beyond violation : on points-of-interest in runtime verification Authors: Colombo, Christian; Pace, Gordon J.; Schneider, Gerardo Abstract: Many formal verification techniques are concerned with comparing system behaviours with formal specifications. Although runtime verification has followed this path (comparing observed traces against formal properties), it has traditionally been burdened with another task—that of raising a flag when a violation is detected. Different approaches can be found in the literature: identifying the earliest such instance, identifying all instances, identifying instances where (potentially future) violations are inevitable, etc. We argue that the lack of a clear distinction between the notion of system correctness and the hard-wired means of identification of points when violation is somehow detected, conflates the notions of points-of-detection and points-of-violation. Frequently, the point at which a point-of-violation may be detected is independent of the point of interest itself, and also independent of the point-of-reaction if a corrective measure is needed. We observe that this distinction becomes more salient in some cases, such as deontic specification languages, which may identify notions such as permission, and in the case of multi-agent systems, where the notion of blame is essential. Using practical and varied examples we motivate why these limitations are significant for the field of runtime verification. Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/147766 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/147764 Title: RVsec : towards a comprehensive technology stack for secure deployment of software monitors Authors: Colombo, Christian; Curmi, Axel; Abela, Robert Abstract: Runtime monitors frequently need to be deployed in highly secure software environments to help further secure the system under scrutiny. In such contexts, the monitor could benefit from security hardening over and above the rest of the system since the monitoring component is of particular interest to the attacker. If the attacker successfully disables the monitor, the attack can be executed without potential alarms being raised, leaving no evidence behind. Furthermore, due to the separation of concerns inherent in runtime verification, monitors are typically separated from the rest of the system, facilitating isolation and a hardened security environment which would otherwise be difficult to achieve for the whole system. The combination of these observations, motivate us to consider a number of approaches for increased monitor security which we present as a technology stack called RVsec which could be instantiated in various contexts. Using a quantum-safe chat application as a case study, we present a pragmatic solution to various threat scenarios while considering the trade-offs in terms of additional setup and runtime costs. Sun, 01 Sep 2024 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/147764 2024-09-01T00:00:00Z