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This report documents the program and the outcomes of Dagstuhl Seminar 23341 "Functionally Safe Multi-Core Systems". The seminar took place at a time when there is significant debate and disagreement in both academia and industry on how future safety-critical systems can be developed, certified, and deployed. This process is increasingly complex, as on the one hand, modern systems must provide more services while, on the other hand, analysing such systems becomes significantly more challenging in a multi-core scenario than it was in the single-core era. It is therefore a vital question to determine how the same level of certainty can be provided in the future. The seminar brought together experts from academia and industry for the three major layers involved in safety-critical systems: application, middleware, and platform. They discussed the different perspectives, which problems are deemed specifically important, and potential solutions. One main focus when organizing the seminar was to not only present the different positions but also to provide space for lengthy discussion and disagreement.

Geotechnically massive strata behave as strong units, rather than the geologically massive description which describes the sedimentary formation. The consequence of such geotechnically massive units to mining is a series of problems associated with these units failing to break up into small blocks. This paper deals with the determination of what constitutes geotechnically massive strata. This is essentially a function of the geology and the mechanical properties of the geological stratigraphic units that need to be combined into geotechnical units. The mechanical properties depend on the rock itself and on the structure in the form of joints and faults. The importance of anisotropic rock behaviour cannot be underestimated and neither can the variations in geology. Structural plate and beam analysis is presented as a method to determine where and at what span the initial fall and subsequent goaf falls will take place. While this is elastic analysis, it should be appreciated that the stronger rocks which lead to massive strata conditions will behave more elastically, and therefore this method of analysis is considered justified in most cases. This approach is considered to be far more usable and reliable than complex numerical analysis, which generally lacks the range of real rock behaviour as a fundamental input and is frequently uncheckable. The use of these established analytical techniques lends confidence to the solutions derived from their use. The pre-existing stresses are important as they will control initial goaf formation. Dynamic support loading is considered as is preconditioning to break massive units down so that they break in smaller blocks.

Conventional mixed-criticality systems (MCS)s are designed to terminate the execution of less critical tasks in exceptional situations so that the timing properties of more critical tasks can be preserved. Such a strategy can be controversial and has proven difficult to implement in practice, as it can lead to hazards and reduced functionality due to the absence of the discarded tasks. To mitigate this issue, the imprecise mixed-critically system model (IMCS) has been proposed. In such a model, instead of completely dropping less-critical tasks, these tasks are executed as much as possible through the use of decreased computation precision. Although IMCS could effectively improve the survivability of the less-critical tasks, it also introduces three key drawbacks - run-time computation errors, real-time performance degradation, and lack of flexibility. In this paper, we present a novel IMCS framework, which can (i) mitigate the computation errors caused by imprecise computation; (ii) achieve real-time performance near to that of a conventional MCS; (iii) enhance system-level throughput; and (iv) provide flexibility for run-time configuration. We describe the design details of HIART-MCS, and then present the corresponding theoretical analysis and optimisation method for its run-time configuration. Finally, HIART-MCS is evaluated against other MCS frameworks using a variety of experimental metrics.

All systems rely on inputs and outputs (I/Os) to perceive and interact with their surroundings. In safety-critical systems, it is important to guarantee both the performance and time-predictability of I/O operations. However, with the continued growth of architectural complexity in modern safety-critical systems, satisfying such real-time requirements has become increasingly challenging due to complex I/O transaction paths and extensive hardware contention. In this paper, we present a new NoC-based Predictable I/O system framework (NPRC-I/O) which reduces this contention and ensures the performance and timepredictability of I/O operations. Specifically, NPRC-I/O contains a programmable I/O command controller (NPRC-CC) and a runtime reconfigurable NoC (RNoC), which provides the capability to adjust I/O transaction paths at run-time. Using this flexibility, we construct an end-to-end transmission latency analysis and an optimisation engine that produces configurations for NPRCI/ O and the I/O traffic in a given system. The constructed analysis and optimisation engine guarantee the timing of all hard realtime traffic while reducing the deadline misses of soft real-time traffic and overall transmission latency.

Coal measure rocks tend to have anisotropic and elastically non-linear behaviour. Understanding this is a key to understanding strata behaviour in coal mines. This paper discusses which properties matter and how they can be measured. Some new test methods are introduced. The paper also discusses the relevance of geophysics in determining these properties.

This paper categorises the different types of coal bursts and gas outbursts in terms of their mechanisms. It is considered to be essentially impossible to predict when one of these events may occur. However, it is possible in many of the cases to predict the velocity of ejection and hence the distance with which particles may travel including bouncing and rolling and sliding. Keeping beyond this stand-off distance ensures the safety of workers from impact. Where gassy fault gouge exists there is no such safe distance. The material involved may be ejected in the form of a turbulent flow which has been described as a coal storm and which can travel great distances. This also involves large amounts of gas with the inherent problems of explosive mixtures. Locating, and determining the size of such geological features is therefore of great importance. Methods of doing this are discussed.