Targeting distributed systems in FastFlow

FastFlow is a structured parallel programming framework targeting shared memory multi-core architectures. In this paper we introduce a FastFlow extension aimed at supporting also a network of multi-core workstations. The extension supports the execution of FastFlow programs by coordinating-in a structured way-the fine grain parallel activities running on a single workstation. We discuss the design and the implementation of this extension presenting preliminary experimental results validating it on state-of-the-art networked multi-core nodes. © 2013 Springer-Verlag.

Inference and Declaration of Independence in Task-Parallel Programs

The inherent difficulty of thread-based shared-memory programming has recently motivated research in high-level, task-parallel programming models. Recent advances of Task-Parallel models add implicit synchronization, where the system automatically detects and satisfies data dependencies among spawned tasks. However, dynamic dependence analysis incurs significant runtime overheads, because the runtime must track task resources and use this information to schedule tasks while avoiding conflicts and races.
We present SCOOP, a compiler that effectively integrates static and dynamic analysis in code generation. SCOOP combines context-sensitive points-to, control-flow, escape, and effect analyses to remove redundant dependence checks at runtime. Our static analysis can work in combination with existing dynamic analyses and task-parallel runtimes that use annotations to specify tasks and their memory footprints. We use our static dependence analysis to detect non-conflicting tasks and an existing dynamic analysis to handle the remaining dependencies. We evaluate the resulting hybrid dependence analysis on a set of task-parallel programs.

Managing adaptivity in parallel systems

The management of non-functional features (performance, security, power management, etc.) is traditionally a difficult, error prone task for programmers of parallel applications. To take care of these non-functional features, autonomic managers running policies represented as rules using sensors and actuators to monitor and transform a running parallel application may be used. We discuss an approach aimed at providing formal tool support to the integration of independently developed autonomic managers taking care of different non-functional concerns within the same parallel application. Our approach builds on the Behavioural Skeleton experience (autonomic management of non-functional features in structured parallel applications) and on previous results on conflict detection and resolution in rule-based systems. © 2013 Springer-Verlag Berlin Heidelberg.

Group work in elementary science:Towards organisational principles for supporting pupil learning

Group work has been promoted in many countries as a key component of elementary science. However, little guidance is given as to how group work should be organised, and because previous research has seldom been conducted in authentic classrooms, its message is merely indicative. A study is reported, which attempts to address these limitations. Twenty-four classes of 10-12-year-old pupils engaged in programmes of teaching on evaporation and condensation, and force and motion. Both programmes were delivered by classroom teachers, and made extensive use of group work. Pupil understanding progressed from pre-tests prior to the programmes to post-tests afterwards, and results suggest that group work played a critical role. Organisational principles are extrapolated from the findings, which could be readily adopted in classrooms. © 2007 Elsevier Ltd. All rights reserved.

Invaders, Launchpads and Hybrids: The Importance of Transmediality in British Science Fiction Film in the 1950s

With its origins in the trick films of the 1890s and early 1900s, British science fiction film has a long history. While Things to Come (1936) is often identified as significant for being written by H.G.Wells, one of the fathers of science fiction as a genre, the importance of the interactions between media in the development of British science fiction film are often set aside. This chapter examines the importance of broadcast media to film-making in Britain, focusing on the 1950s as a period often valourised in writings about American science fiction, to the detriment of other national expressions of the genre. This period is key to the development of the genre in Britain, however, with the establishment of television as a popular medium incorporating the development of domestic science fiction television alongside the import of American products, together with the spread of the very term ‘science fiction’ through books, pulps and comics as well as radio, television and cinema. It was also the time of a backlash against the perceived threat of American soft cultural power embodied in the attractive shine of science fiction with its promise of a bright technological future. In particular, this chapter examines the significance of the relationship between the BBC television and radio services and the film production company Hammer, which was responsible for multiple adaptations of BBC properties, including a number of science fiction texts. The Hammer adaptation of the television serial The Quatermass Experiment proved to be the first major success for the company, moving it towards its most famous identity as producer of horror texts, though often horror with an underlying scientific element, as with their successful series of Frankenstein films. This chapter thus argues that the interaction between film and broadcast media in relation to science fiction was crucial at this historical juncture, not only in helping promote the identities of filmmakers like Hammer, but also in supporting the identity of the BBC and its properties, and in acting as a nexus for the then current debates on taste and national identity.

Management in distributed systems: A semi-formal approach

The reverse engineering of a skeleton based programming environment and redesign to distribute management activities of the system and thereby remove a potential single point of failure is considered. The Ore notation is used to facilitate abstraction of the design and analysis of its properties. It is argued that Ore is particularly suited to this role as this type of management is essentially an orchestration activity. The Ore specification of the original version of the system is modified via a series of semi-formally justified derivation steps to obtain a specification of the decentralized management version which is then used as a basis for its implementation. Analysis of the two specifications allows qualitative prediction of the expected performance of the derived version with respect to the original, and this prediction is borne out in practice.

Model checking support for conflict resolution in multiple non-functional concern management

When implementing autonomic management of multiple non-functional concerns a trade-off must be found between the ability to develop independently management of the individual concerns (following the separation of concerns principle) and the detection and resolution of conflicts that may arise when combining the independently developed management code. Here we discuss strategies to establish this trade-off and introduce a model checking based methodology aimed at simplifying the discovery and handling of conflicts arising from deployment-within the same parallel application-of independently developed management policies. Preliminary results are shown demonstrating the feasibility of the approach.

Network Based Malware Detection in Virtualised Environment

While virtualisation can provide many benefits to a networks infrastructure, securing the virtualised environment is a big challenge. The security of a fully virtualised solution is dependent on the security of each of its underlying components, such as the hypervisor, guest operating systems and storage.

This paper presents a single security service running on the hypervisor that could potentially work to provide security service to all virtual machines running on the system. This paper presents a hypervisor hosted framework which performs specialised security tasks for all underlying virtual machines to protect against any malicious attacks by passively analysing the network traffic of VMs. This framework has been implemented using Xen Server and has been evaluated by detecting a Zeus Server setup and infected clients, distributed over a number of virtual machines. This framework is capable of detecting and identifying all infected VMs with no false positive or false negative detection.