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Traditional speedup models, such as Amdahl's Law, Gustafson's, and Sun and Ni's models, have helped the research community and industry to better understand the performance capabilities of systems and the parallelizability of applications. Mostly targeting homogeneous hardware platforms or a limited form of processor heterogeneity, these models do not cover newly emerging multi-core heterogeneous architectures. This paper reports novel speedup and energy consumption models based on a more general representation of heterogeneity, called normal form heterogeneity, supporting a wide range of heterogeneous many-core architectures. The modelling method aims to predict system energy efficiency and performance ranges and facilitates research and development for the hardware and system software levels. Extensive experimentation on an off-the-shelf big.LITTLE heterogeneous platform validates the models showing less than 1% error for speedup and less than 4% error for power dissipation. The practical use of the method is demonstrated with a quantitative study of system load balancing efficiency.

Abstract. In this paper we continue work to investigate how we can engage young adults in behaviors of recycling and the prevention of food waste through social media and persuasive and ubiquitous computing systems. Our previous work with BinCam, a two-part design combining a system for the collection of waste-related behaviors with a Facebook application, suggested that although this ubiquitous system could raise awareness of recycling behavior, engagement with social media remained low. In this paper we reconsider our design in terms of engagement, examining both the theoretical and practical ways in which engagement can be designed for. This paper presents findings from a new user study exploring the re-design of the social media interface following this analysis. By incorporating elements of gamification, social support and improved data visualization, we contribute insights on the relative potential of these techniques to engage individuals across the lifespan of a system's deployment.

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Smart learning environments offer rich opportunities for language learners. In particular, context-aware systems which allow learners' progress to be sensed within and across an activity, enable instructed language learning to move beyond the traditional confines of the classroom walls. In this paper we present the European Kitchen, a real-world task-based environment for cooking and language learning. In doing so, we demonstrate how specific design decisions, in the development of this longer-term iterative design project, conjoin Human Computer Interaction practice and learning theory for situated language learning. We also show how this approach is combined with Conversation Analysis, which is used as a tool to measure the impact of these decisions on the interactions taking place in and with the kitchen. Our work reveals that in order to design for and evaluate effective and meaningful language learning, there should be more balance between technologically-driven theory and theory driven research which has a strong pedagogical foundation. Our work has implications for a transferable, interdisciplinary model of task-based, situated learning which can be applied and adapted to different skill and knowledge sets.