794,174 research outputs found

    Understanding Consumer Behaviour to Reduce Environmental Impacts through Sustainable Product Design

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    The use phase of the lifecycle of electrical products has a significant environmental impact, mainly determined by the consumer’s behaviour. Many consumers do not make the link between their daily consumption behaviour in the household and environmental problems such as climate change. In the 21st century, the residential sector, together with transport and industry, is one of the largest man-made contributors in the UK to climate change. It is argued that technological innovations, current eco-efficient products and consumer education have been ineffective in creating the long term radical behavioural change needed to reduce the impact of product use. Products, as the interface between consumers and consumption activities, have the potential to influence the way in which consumption occurs. In the sustainable design field however, designer responsibility traditionally considers raw material selection and product disposal. There is limited work that addresses the environmental impacts relating directly to use behaviour of the product. This paper illustrates that user behaviour studies can be the preliminary step for designers to improve energy efficiency of products. A single product type, household cold appliance, was chosen as a case to explore the capacity of designer-conducted user study to identify unsustainable aspects of product use. Adopting a user-centred approach, two pilot studies were used to gain an insight into domestic fridge and freezer use in the UK. Qualitative ethnographical research methods were employed to investigate the daily practices and “real” needs of user as well as the connection between the knowledge, attitudes, intention and actual action. The design suggestions drawn from the user behaviour analysis provide examples of how energy impact level of the interaction with the product can be reduced through design. Keywords: User-Centred Research; Sustainable Product Design; Changing Consumer Behaviour; Design Research; Household Energy Consumption; Household Cold Appliance.</p

    Influence Maximization Meets Efficiency and Effectiveness: A Hop-Based Approach

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    Influence Maximization is an extensively-studied problem that targets at selecting a set of initial seed nodes in the Online Social Networks (OSNs) to spread the influence as widely as possible. However, it remains an open challenge to design fast and accurate algorithms to find solutions in large-scale OSNs. Prior Monte-Carlo-simulation-based methods are slow and not scalable, while other heuristic algorithms do not have any theoretical guarantee and they have been shown to produce poor solutions for quite some cases. In this paper, we propose hop-based algorithms that can easily scale to millions of nodes and billions of edges. Unlike previous heuristics, our proposed hop-based approaches can provide certain theoretical guarantees. Experimental evaluations with real OSN datasets demonstrate the efficiency and effectiveness of our algorithms.Comment: Extended version of the conference paper at ASONAM 2017, 11 page

    Phenomenology of Neutrino Oscillations at the Neutrino Factory

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    We consider the prospects for a neutrino factory to measure mixing angles, the CP violating phase and mass-squared differences by detecting wrong-charged muons arising from the chain \mu^+ to \nu_e to \nu_\mu\ to \mu^- and the right-charged muons coming from the chain \mu^+ to \bar{\nu}_\mu\ to \bar{\nu}_\mu\ to \mu^+ (similar to \mu^- chains), where \nu_e to \nu_\mu\ and \bar{\nu}_\mu\ to \bar{\nu}_\mu\ are neutrino oscillation channels through a long baseline. First, we perform the baseline and energy optimization of the neutrino factory including the latest simulation results from the magnetized iron neutrino detector (MIND). Second, we study physics with near detectors and consider the treatment of systematic errors including cross section errors, flux errors, and background uncertainties. Third, the effects of one additional massive sterile neutrino are investigated in the context of near and far detector combinations.Comment: 4 pages, 3 figures, proceedings for TAUP201

    Universal Spatiotemporal Sampling Sets for Discrete Spatially Invariant Evolution Systems

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    Let (I,+)(I,+) be a finite abelian group and A\mathbf{A} be a circular convolution operator on 2(I)\ell^2(I). The problem under consideration is how to construct minimal ΩI\Omega \subset I and lil_i such that Y={ei,Aei,,Aliei:iΩ}Y=\{\mathbf{e}_i, \mathbf{A}\mathbf{e}_i, \cdots, \mathbf{A}^{l_i}\mathbf{e}_i: i\in \Omega\} is a frame for 2(I)\ell^2(I), where {ei:iI}\{\mathbf{e}_i: i\in I\} is the canonical basis of 2(I)\ell^2(I). This problem is motivated by the spatiotemporal sampling problem in discrete spatially invariant evolution systems. We will show that the cardinality of Ω\Omega should be at least equal to the largest geometric multiplicity of eigenvalues of A\mathbf{A}, and we consider the universal spatiotemporal sampling sets (Ω,li)(\Omega, l_i) for convolution operators A\mathbf{A} with eigenvalues subject to the same largest geometric multiplicity. We will give an algebraic characterization for such sampling sets and show how this problem is linked with sparse signal processing theory and polynomial interpolation theory

    On Using Encryption Techniques to Enhance Sticky Policies Enforcement

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    How to enforce privacy policies to protect sensitive personal data has become an urgent research topic for security researchers, as very little has been done in this field apart from some ad hoc research efforts. The sticky policy paradigm, proposed by Karjoth, Schunter, and Waidner, provides very useful inspiration on how we can protect sensitive personal data, but the enforcement is very weak. In this paper we provide an overview of the state of the art in enforcing sticky policies, especially the concept of sticky policy enforcement using encryption techniques including Public-Key Encryption (PKE), Identity-Based Encryption (IBE), Attribute-Based Encryption (ABE), and Proxy Re-Encryption (PRE). We provide detailed comparison results on the (dis)advantages of these enforcement mechanisms. As a result of the analysis, we provide a general framework for enhancing sticky policy enforcement using Type-based PRE (TPRE), which is an extension of general PRE

    A Counter Example of Invariant Deformation Quantization

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    In this note, we will show one example of hamiltonian Lie algebra action which has no invariant star product.Comment: 8page
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