Reconceptualising professional development in early childhood education. A study on teachers' professionalism carried out in Bologna province.

The research undertaken for this doctoral thesis explores the issue of teachers professionalism within pre-school institutions. The issue of early childhood professionalism has become increasingly important in the academic debate over the last decade as it is documented by a growing body of research published on the topic both nationally (Contini & Manini, 2007; Bondioli & Ferrari, 2004) and internationally (Peeters, 2008; Urban & Dalli, 2008; Urban, 2010). The study presented in this thesis aims at investigating teachers’ conceptualisations of professionalism by focusing on their understandings of educational work. The idea standing at the core of this research is that exploring the concept of professionalism from a ground-up perspective could lead to important reflections for a re-conceptualisation of professional development as a space for change directed from within institutions. The study is framed within a broadly sociological concern that inform the data analysis by contextualising the issue of early childhood professionalism in the contemporary socio-political arena. The research involves sixty teachers operating in state, municipal and private pre-school institutions located in Bologna province that took part to focus groups and interviews. The empirical materials, consisting of oral and written statements, are interpreted through phenomenographical analysis that gives account of how features of professionalism vary across the different institutional settings in which they are played out. This thesis, written in English and informed by an European research background, offers a contribution to the furthering of systemic approaches to the investigation of early childhood education professionalism in the context of the national and international academic debate.

Operating System Contribution to Composable Timing Behaviour in High-Integrity Real-Time Systems

The development of High-Integrity Real-Time Systems has a high footprint in terms of human, material and schedule costs. Factoring functional, reusable logic in the application favors incremental development and contains costs. Yet, achieving incrementality in the timing behavior is a much harder problem. Complex features at all levels of the execution stack, aimed to boost average-case performance, exhibit timing behavior highly dependent on execution history, which wrecks time composability and incrementaility with it. Our goal here is to restitute time composability to the execution stack, working bottom up across it. We first characterize time composability without making assumptions on the system architecture or the software deployment to it. Later, we focus on the role played by the real-time operating system in our pursuit. Initially we consider single-core processors and, becoming less permissive on the admissible hardware features, we devise solutions that restore a convincing degree of time composability. To show what can be done for real, we developed TiCOS, an ARINC-compliant kernel, and re-designed ORK+, a kernel for Ada Ravenscar runtimes. In that work, we added support for limited-preemption to ORK+, an absolute premiere in the landscape of real-word kernels. Our implementation allows resource sharing to co-exist with limited-preemptive scheduling, which extends state of the art. We then turn our attention to multicore architectures, first considering partitioned systems, for which we achieve results close to those obtained for single-core processors. Subsequently, we shy away from the over-provision of those systems and consider less restrictive uses of homogeneous multiprocessors, where the scheduling algorithm is key to high schedulable utilization. To that end we single out RUN, a promising baseline, and extend it to SPRINT, which supports sporadic task sets, hence matches real-world industrial needs better. To corroborate our results we present findings from real-world case studies from avionic industry.