1,721,626 research outputs found
Tropical and extratropical controls of Gulf of California surges and summertime precipitation over the Southwestern United States
No full textIn this study ERA-Interim data are used to study the influence of Gulf of California (GoC) moisture surges on the North American monsoon (NAM) precipitation over Arizona and western New Mexico (AZWNM), as well as the connection with larger-scale tropical and extratropical variability. To identify GoC surges, an improved index based on principal component analyses of the near-surface GoC winds is introduced. It is found that GoC surges explain up to 70% of the summertime rainfall over AZWNM. The number of surges that lead to enhanced rainfall in this region varies from 4 to 18 per year and is positively correlated with annual summertime precipitation. Regression analyses are performed to explore the relationship between GoC surges, AZWNM precipitation, and tropical and extratropical atmospheric variability at the synoptic (2-8 days), quasi-biweekly (10-20 days), and subseasonal (25-90 days) time scales. It is found that tropical and extratropical waves, responsible for intrusions of moist tropical air into midlatitudes, interact on all three time scales, with direct impacts on the development of GoC surges and positive precipitation anomalies over AZWNM. Strong precipitation events in this region are, however, found to be associated with time scales longer than synoptic, with the quasi-biweekly and subseasonal modes playing a dominant role in the occurrence of these more extreme events
Insurance fraud evaluation. A fuzzy expert system
No full textAll the studies dealing with the Italian Insurance market, show that fraud is a raising, relevant problem of that sector. ISVAP results (Istituto per la Vigilanza Sulle Assicurazioni Private e di Interesse Collettivo) stressed the remarkable number of around 200.000 fraudulent claims in Italy for year 1998, 155.550 referring to the lone car sector. This occurrence leads the insurance market to higher costs for honest customers and to a low efficiency of the whole system. To solve the problem, ISVAP itself is going to create a Database of actors, vehicles and fraud patterns to provide Companies with a tool to easier investigate on suspicious cases. On their side, Companies are trying to embed real “Fraud Units” in their typical activity, to identify suspicious cases and fraudulent patterns either in the insuring phase or in the settlement of claims. All the efforts to face the problem aim to redraw the issue as an industrial cost problem to handle general costs, distribution costs and claim compensation with efficiency principles. Against a deeper, more efficient investigation activity, Company shall face three opposite problems: high cost of expert activity, the request of fast settlements and, for Italian market, the requirement to cover any people who ask for a Policy. Fraud investigation and fast settlement of claims are antithetical activity. Call centres well reply to speed request, but let unsolved or even worsen the analysis on suspicious claims. The low competence of call centres employees doesn’t allow to leave them a first level of judgement on the genuine nature of claims. Thus proceeding, any audit analysis requires fraud experts. That’s the reason why fast settlement tends to generate extra costs in fraud investigations. What Companies need is a standard, automatic, fast control method to filter real suspicious cases to fraud experts and let Call centres free to pay immediately the majority of claims. Unsuspicious claims can thus be settled automatically, even by the non-expert call centre operators, while claims that exceed a fixed threshold value will be investigate by fraud experts. Claim auditors can so dedicate their activity to potentially fraudulent claims only. The aim of this paper is showing how a Fuzzy Logic Control (FLC) model can efficiently evaluate an “Index of suspect” on each claim, in order to stress fraudulent situation to be investigated from the expert
Einstein, Laub and Unipolar Induction
No full textIn the first passages of 1905 paper “On the electrodynamics of moving
bodies”, Einstein underscored the theoretical asymmetries in the Maxwell and
Lorentz explanation of electromagnetic induction. In the second part of the
paper, the elctrodynamical part, he stated that “questions as to the > of
electrodynamic electromotive forces (unipolar machines) become meaningless.”
At that time, unipolar machines were well known devices: through two sliding
electric contacts, connecting the pole and the equatorial circle of a cylindrical
rotating magnet, flowed an electric current. Huge unipolar inductors had
important technological applications in spite of some theoretical problem
concerning the explanation of the emerging induced currents. Were lines of
force in motion together with the magnet or were not? Were the electric wires or
the magnet itself the > of the electromotive force?
In 1908, A. Einstein and J. Laub claimed that the different predictions,
about unipolar induction in dielectric magnets, of Lorentz and Einstein
electrodynamics, allowed scientists to set the comparison between them on
experimental ground
Rating Politics Fuzzy Logic Control
No full textQuesto modello nasce dalla opportunità di descrivere ed analizzare l’attività politica secondo criteri oggettivi che consentano una valutazione efficace dell’operato dei singoli partiti politici. Il modello si propone di studiare ed esprimere una valutazione sul comportamento pregresso di ciascun partito e sui contenuti dei programmi elettorali presentati in sede di elezioni. La valutazione dell’attività dei partiti e delle priorità dei programmi elettorali viene analizzata in relazione ai desiderata dell’elettorato per evidenziare eventuali differenze e similarità
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