660 research outputs found

    Location relevance and diversity in symbolic trajectories with application to telco data

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    We present an approach to the discovery and characterization of relevant locations and related mobility patterns in symbolic trajectories built on call detail records - CDRs - of mobile phones (telco trajectories). While the discovery of relevant locations has been widely investigated for continuous spatial trajectories (e.g., stay points detection methods), it is not clear how to deal with the problem when the movement is defined over a discrete space and the locations are symbolic, noisy and irregularly sampled, such as in telco trajectories. In this paper, we propose a methodological approach structured in two steps, called trajectory summarization and summary trajectories analysis, respectively, the former for removing noise and irrelevant locations; the latter to synthesize key mobility features in a few novel indicators. We evaluate the methodology over a dataset of approx 17,000 trajectories with 55 million points and spanning a period of 67 days. We find that trajectory summarization does not compromise data utility, while significantly reducing data size. Moreover, the mobility indicators provide novel insights into human mobility behavior

    Early stage Design Workflow for high Energy Performance Multi-storey Residential Buildings

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    This paper presents a methodology to optimize building envelope energy performance for multi-storey residential buildings using a design performance model approach. Five analysis techniques, applied to a database of parametric simulation results, are proposed to derive information on various building performance features that can support early design decisions. Information may include optimal combination of design parameter values to achieve lowest energy consumption, or the relative impact of design parameters on a given design, such as a base case. A workflow template is established to provide support for the design process of energy efficient multi-storey residential buildings. This template can form a basis for the development of an interactive tool that integrates energy performance principles into early stage design decisions. The application of this methodology to a building in Vancouver (BC, Canada, 49°N) is presented as a case study. Results of this application demonstrates that adopting a specific combination of building envelope parameters, thermal load can be reduced by up to 85% as compared to a base case designed according to commonly built apartment buildings in the studied location. 

    8Be cluster emission versus alpha evaporation in 28Si + 12C

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    The possible occurence of highly deformed configurations in the 40^{40}Ca di-nuclear system formed in the 28^{28}Si + 12^{12}C reaction is investigated by analyzing the spectra of emitted light charged particles. Both inclusive and exclusive measurements of the heavy fragments (A ≥\geq 10) and their associated light charged particles (protons and α\alpha particles) have been made at the IReS Strasbourg {\sc VIVITRON} Tandem facility at bombarding energies of ElabE_{lab} (28^{28}Si) = 112 MeV and 180 MeV by using the {\sc ICARE} charged particle multidetector array. The energy spectra, velocity distributions, in-plane and out-of-plane angular correlations of light charged particles are compared to statistical-model calculations using a consistent set of parameters with spin-dependent level densities. This spin dependence approach suggests the onset of large nuclear deformation in 40^{40}Ca at high spin. This conclusion might be connected with the recent observation of superdeformed bands in the 40^{40}Ca nucleus. The analysis of α\alpha particles in coincidence with 32^{32}S fragments suggests a surprisingly strong 8^{8}Be cluster emission of a binary nature.Comment: 39 pages 15 figure

    Search for emission of unstable 8^8Be clusters from hot 40^40Ca and 56^56Ni nuclei

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    The possible occurence of highly deformed configurations is investigated in the 40^{40}Ca and 56^{56}Ni di-nuclear systems as formed in the 28^{28}Si + 12^{12}C and 28^{28}Si + 28^{28}Si reactions, respectively, by using the properties of emitted light charged particles. Inclusive as well as exclusive data of the heavy fragments (A ≥\geq 6) and their associated light charged particles (p, d, t, and α\alpha-particles) have been collected at the IReS Strasbourg VIVITRON Tandem facility with two bombarding energies Elab(28E_{lab}(^{28}Si) = 112 and 180 MeV by using the ICARE charged particle multidetector array, which consists of nearly 40 telescopes. The measured energy spectra, velocity distributions, in-plane and out-of-plane angular correlations are analysed by Monte Carlo CASCADE statistical-model calculations using a consistent set of parameters with spin-dependent level densities. Although significant deformation effects at high spin are needed, the remaining disagreement observed in the 28^{28}Si + 12^{12}C reaction for the S evaporation residue suggests an unexpected large unstable 8^{8}Be cluster emission of a binary nature.Comment: 13 pages latex, 9 eps figures. Paper presented at the XXXIX International Winter Meeting on Nuclear Physics, Bormio(Italy) January 22-27, 2001 (to be published at Ricerca Scientifica ed Educazione Permanente
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