527 research outputs found

    Multisensor Out Of Sequence Data Fusion for Estimating the State of Discrete Control Systems

    Get PDF
    The fusion center of a complex control system estimates its state with the information provided by different sensors. Physically distributed sensors, communication networks, pre-processing algorithms, multitasking, etc, introduce non-systematic delays in the arrival of information to the fusion center, making the information available out-of-sequence (OOS). For real-time control systems, the state has to be efficiently estimated with all the information received so far. So, several solutions of the OOS problem for dynamic multiple-input multiple-output (MIMO) discrete control systems traditionally solved by the Kalman filter (KF) have been proposed recently. This paper presents two new streamlined algorithms for the linear and non-linear case. IFAsyn, the linear algorithm, is equivalent to other optimal solutions but more general, efficient and easy to implement. EIFAsyn, the nonlinear one, is a new solution of the OOS problem in the extended KF (EKF) framework

    BARTER:promoting local spending behavior

    Get PDF
    In the wake of the 2008 economic collapse, there is renewed interest in strategies for ensuring the future economic success of nations in a globalized marketplace. One of the main ideas being championed by governments is to promote growth by encouraging local spending, although it is not clear how to motivate this behavioral shift. Local currency initiatives are increasingly popular, though due to certain practicalities are rarely successful in fostering long term and widespread change in spending behaviors. We report on the development of a persuasive system (BARTER) that leverages mobile and ubiquitous technology to overcome some of the limitations of local currencies, while also providing users with the insight needed to determine for themselves how local spending may benet their community

    HI asymmetry in the isolated galaxy CIG 85 (UGC 1547)

    Full text link
    We present the results from the Giant Metrewave Radio Telescope (GMRT) interferometric HI and 20 cm radio continuum observations of CIG 85, an isolated asymmetric galaxy from the AMIGA (Analysis of the Interstellar Medium of Isolated GAlaxies) sample. Despite being an isolated galaxy, CIG 85 showed an appreciable optical and HI spectral asymmetry and therefore was an excellent candidate for resolved HI studies to understand the reasons giving rise to asymmetries in isolated galaxies. The galaxy was imaged in HI and 20 cm radio continuum using the GMRT. For a detailed discussion of the results we also made use of multi-wavelength data from archival SDSS, GALEX and Halpha imaging. We find the HI in CIG 85 to have a clumpy, asymmetric distribution which in the NW part is correlated with optical tail like features, but the HI velocity field displays a relatively regular rotation pattern. Evaluating all the observational evidence, we come to a conclusion that CIG 85 is most likely a case of a disturbed spiral galaxy which now appears to have the morphology of an irregular galaxy. Although it is currently isolated from major companions, the observational evidence is consistent with HI asymmetries, a highly disturbed optical disk and recent increase in star formation having been caused by a minor merger, remnants of which are now projected in front of the optical disk. If this is correct, the companion will be fully accreted by CIG 85 in the near future.Comment: 10 pages, 9 figures, accepted in A&

    Automatic Adaptation of Airport Surface Surveillance to Sensor Quality

    Get PDF
    This paper describes a novel method to enhance current airport surveillance systems used in Advanced Surveillance Monitoring Guidance and Control Systems (A-SMGCS). The proposed method allows for the automatic calibration of measurement models and enhanced detection of nonideal situations, increasing surveillance products integrity. It is based on the definition of a set of observables from the surveillance processing chain and a rule based expert system aimed to change the data processing method

    Some considerations concerning the challenge of incorporating social variables into epidemiological models of infectious disease transmission

    Get PDF
    Incorporation of ‘social’ variables into epidemiological models remains a challenge. Too much detail and models cease to be useful; too little and the very notion of infection —a highly social process in human populations—may be considered with little reference to the social. The French sociologist Emile Durkheim proposed that the scientific study of society required identification and study of ‘social currents.’ Such ‘currents’ are what we might today describe as ‘emergent properties,’ specifiable variables appertaining to individuals and groups, which represent the perspectives of social actors as they experience the environment in which they live their lives. Here we review the ways in which one particular emergent property, hope, relevant to a range of epidemiological situations, might be used in epidemiological modelling of infectious diseases in human populations. We also indicate how such an approach might be extended to include a range of other potential emergent properties to repre

    Generic multisensor multitarget bias estimation architecture

    Get PDF
    Current bias estimation algorithms for air traffic control (ATC) surveillance are focused on radar sensors, but the integration of new sensors (especially automatic dependent surveillance-broadcast and wide area multilateration) demands the extension of traditional procedures. This study describes a generic architecture for bias estimation applicable to multisensor multitarget surveillance systems. It consists on first performing bias estimations using measurements from each target, of a subset of sensors, assumed to be reliable, forming track bias estimations. All track bias estimations are combined to obtain, for each of those sensors, the corresponding sensor bias. Then, sensor bias terms are corrected, to subsequently calculate the target or sensor-target pair specific biases. Once these target-specific biases are corrected, the process is repeated recursively for other sets of less reliable sensors, assuming bias corrected measures from previous iterations are unbiased. This study describes the architecture and outlines the methodology for the estimation and the bias estimation design processes. Then the approach is validated through simulation, and compared with previous methods in the literature. Finally, the study describes the application of the methodology to the design of the bias estimation procedures for a modern ATC surveillance application, specifically for off-line assessment of ATC surveillance performance

    Simpósio Nacional de Culturas Agro-industriais Potencialidades e perspectivas

    Get PDF
    Simpósio Nacional de Culturas Agro-industriais Potencialidades e perspectiva

    Consumer satisfaction with local retail diversity in the UK: effects of supermarket access, brand variety, and social deprivation

    Get PDF
    Levels of concentration in the grocery sector have led to concerns about reduced diversity of local retail provision and its potential negative effects on consumer welfare and choice. Using empirical evidence from a study of consumer perceptions of retail choice across nine purposefully sampled neighbourhoods in the city of Worcester in the UK, the paper illuminates consumer satisfaction with local provision and investigates how satisfaction varies with the local mix of grocery stores. The study adopts a stated-preference approach with realistic but hypothetical scenarios being presented to consumers in which the level, form, brand composition, and accessibility of local retail provision is systematically varied to gauge the sensitivity of householders in different types of neighbourhoods to variations in local retail assortments. The contributions of the paper are reflected in three main findings: (1) residents value having a large supermarket close by and reveal that they value diversity of provision rather than overconcentration; (2) consumers in deprived areas overall display greater satisfaction for the same offer than consumers in less deprived areas; and (3) although small stores in a local store assortment significantly contribute to reducing dissatisfaction with the local retail offer, they contribute little to achieving higher levels of consumer satisfaction. The study stresses the need for planners and policy makers to maximise choice and welfare through both the number and the diversity of stores in local neighbourhood areas
    corecore