527 research outputs found
Multisensor Out Of Sequence Data Fusion for Estimating the State of Discrete Control Systems
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
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
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The National Eclipse Weather Experiment: an assessment of citizen scientist weather observations
The National Eclipse Weather Experiment (NEWEx) was a citizen science project designed to assess the effects of the 20 March 2015 partial solar eclipse on the weather over the United Kingdom (UK). NEWEx had two principal objectives: to provide a spatial network of meteorological observations across the UK to aid the investigation of eclipse induced weather changes; and to develop a nationwide public engagement activity based participation of citizen scientists. In total NEWEx collected 15606 observations of air temperature, cloudiness, and wind speed and direction from 309 locations across the UK, over a 3 hour window spanning the eclipse period. The headline results were processed in near real-time, immediately published on-line,
and featured in UK national press articles on the day of the eclipse. Here we describe the technical development of NEWEx and how the observations provided by the citizen scientists were analysed. By comparing the results of the NEWEx analyses with results from other investigations of the same eclipse using different observational networks, including measurements from the University of Reading’s Atmospheric Observatory, we demonstrate that NEWEx provided a fair representation of the change in the UK meteorological conditions throughout the eclipse. Despite the simplicity of the approach adopted, robust reductions in both temperature and wind speed during the eclipse were observed
HI asymmetry in the isolated galaxy CIG 85 (UGC 1547)
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&
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National Eclipse Weather Experiment use and evaluation of a citizen science tool for schools outreach
The National Eclipse Weather Experiment (NEWEx) was a citizen science project for atmospheric data
collection from the partial solar eclipse of 20th March 2015. Its role as a tool for schools’ outreach is
discussed here, in seeking to bridge the gap between self-identification with the role of a scientist and
engagement with science, technology, engineering and maths (STEM) subjects. (The science data generated
has had other uses beyond this, explored elsewhere.) We describe the design of webforms for weather data
collection, and the use of several external partners for the dissemination of the project nationwide. We
estimate that up to 3500 pupils and teachers took part in this experiment, through the 127 schools’
postcodes identified in the data submission. Further analysis revealed that 43.3% of the schools were primary schools and 35.4% secondary. 96.3% of participants reported themselves as “captivated” or “inspired” by NEWEx. We also found that 60% of schools who took part in the experiment lie within the highest quintiles of engagement with higher education, which emphasises the need for the scientific
community to be creative when using citizen science to target minority audiences
Automatic Adaptation of Airport Surface Surveillance to Sensor Quality
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
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
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
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
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
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