2,411 research outputs found

    Ensemble interpolation methods for spatio-temporal data modelling

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    Real time weather forecasting is a highly influential tool in decision making for agriculture. Geographic Information Systems (GIS) can be built to provide information about topographic data such as elevation and distance to oceans or water reservoirs. This data has begun to have increased availability, providing easier access for developing new applications. By using geographic information together with terrestrial measurements from weather stations, the spatial and temporal scales of the climatic variables can be analyzed by interpolation and forecasting. Most of the interpolation methods provided in common GIS tools are only related to the spatial domain, limiting its use in numerical modelling and prediction of climatic states. However, by adopting a Bayesian approach, it appears possible to estimate the dynamic behaviour of the unobserved climate pattern using a state-space representation. Using this framework, the ensemble Kalman filter or a more general sequential Monte Carlo method could be used for the estimation procedure. A wireless sensor network providing continuous data to populate such a model is described here for potential application of this approach

    Modular sensor nodes for environmental data monitoring

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    A framework for modular wireless sensor networks (WSN) designed to capture and monitor micro-climates in a crop field. WSN is rapidly improving in automotive industry, agricultural, industrial and environmental monitoring and many other areas. Moulder architecture minimises the software upgrade down time and enables hardware reusability. Recent developments and advances in wireless technology as well as affordability give rise to this emerging field in the realm of Precision Agriculture (PA). Vineyard monitoring is an emerging application field in PA

    Photoemission evidence for crossover from Peierls-like to Mott-like transition in highly strained VO2_2

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    We present a spectroscopic study that reveals that the metal-insulator transition of strained VO2_2 thin films may be driven towards a purely electronic transition, which does not rely on the Peierls dimerization, by the application of mechanical strain. Comparison with a moderately strained system, which does involve the lattice, demonstrates the crossover from Peierls- to Mott-like transitions

    Automated Ecological Assessment of Physical Activity: Advancing Direct Observation.

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    Technological advances provide opportunities for automating direct observations of physical activity, which allow for continuous monitoring and feedback. This pilot study evaluated the initial validity of computer vision algorithms for ecological assessment of physical activity. The sample comprised 6630 seconds per camera (three cameras in total) of video capturing up to nine participants engaged in sitting, standing, walking, and jogging in an open outdoor space while wearing accelerometers. Computer vision algorithms were developed to assess the number and proportion of people in sedentary, light, moderate, and vigorous activity, and group-based metabolic equivalents of tasks (MET)-minutes. Means and standard deviations (SD) of bias/difference values, and intraclass correlation coefficients (ICC) assessed the criterion validity compared to accelerometry separately for each camera. The number and proportion of participants sedentary and in moderate-to-vigorous physical activity (MVPA) had small biases (within 20% of the criterion mean) and the ICCs were excellent (0.82-0.98). Total MET-minutes were slightly underestimated by 9.3-17.1% and the ICCs were good (0.68-0.79). The standard deviations of the bias estimates were moderate-to-large relative to the means. The computer vision algorithms appeared to have acceptable sample-level validity (i.e., across a sample of time intervals) and are promising for automated ecological assessment of activity in open outdoor settings, but further development and testing is needed before such tools can be used in a diverse range of settings

    Fingerprint oxygen redox reactions in batteries through high-efficiency mapping of resonant inelastic X-ray scattering

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    Realizing reversible reduction-oxidation (redox) reactions of lattice oxygen in batteries is a promising way to improve the energy and power density. However, conventional oxygen absorption spectroscopy fails to distinguish the critical oxygen chemistry in oxide-based battery electrodes. Therefore, high-efficiency full-range mapping of resonant inelastic X-ray scattering (mRIXS) has been developed as a reliable probe of oxygen redox reactions. Here, based on mRIXS results collected from a series of Li Ni Co Mn O electrodes at different electrochemical states and its comparison with peroxides, we provide a comprehensive analysis of five components observed in the mRIXS results. While all the five components evolve upon electrochemical cycling, only two of them correspond to the critical states associated with oxygen redox reactions. One is a specific feature at 531.0 eV excitation and 523.7 eV emission energy, the other is a low-energy loss feature. We show that both features evolve with electrochemical cycling of Li Ni Co Mn O electrodes, and could be used for characterizing oxidized oxygen states in the lattice of battery electrodes. This work provides an important benchmark for a complete assignment of all mRIXS features collected from battery materials, which sets a general foundation for future studies in characterization, analysis, and theoretical calculation for probing and understanding oxygen redox reactions. 1.17 0.21 0.08 0.54 2 1.17 0.21 0.08 0.54

    IDENTIFIED (integrated dictionary-based extraction of non-language-dependent token information for forensic identification, examination, and discrimination): A dictionary-based system for extracting source code metrics for software forensics

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    The frequency and severity of computer-based attacks such as viruses and worms, logic bombs, trojan horses, computer fraud, and plagiarism of software code have all become of increasing concern to many of those involved with information systems. Part of the difficulty experienced in collecting evidence regarding the attack or theft in such situations has been the definition and collection of appropriate measurements to use in models of authorship. With this purpose in mind a system called IDENTIFIED is being developed to assist with the task of software forensics which is the use of software code authorship analysis for legal or official purposes. IDENTIFIED uses combinations of wildcards and special characters to define count-based metrics, allows for hierarchical metametric definitions, automates much of the file handling task, extracts metric values from source code, and assists with the analysis and modelling processes. It is hoped that the availability of such tools will encourage more detailed research into this area of ever-increasing importance

    Visible light-driven H2 production over highly dispersed Ruthenia on Rutile TiO2 nanorods

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    The immobilization of miniscule quantities of RuO2 (~0.1%) onto one-dimensional (1D) TiO2 nanorods (NRs) allows H2 evolution from water under visible light irradiation. Rod-like rutile TiO2 structures, exposing preferentially (110) surfaces, are shown to be critical for the deposition of RuO2 to enable photocatalytic activity in the visible region. The superior performance is rationalized on the basis of fundamental experimental studies and theoretical calculations, demonstrating that RuO2(110) grown as 1D nanowires on rutile TiO2(110), which occurs only at extremely low loads of RuO2, leads to the formation of a heterointerface that efficiently adsorbs visible light. The surface defects, band gap narrowing, visible photoresponse, and favorable upward band bending at the heterointerface drastically facilitate the transfer and separation of photogenerated charge carriers.Peer ReviewedPostprint (published version
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