7,824 research outputs found

    Iterated Function System Models in Data Analysis: Detection and Separation

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    We investigate the use of iterated function system (IFS) models for data analysis. An IFS is a discrete dynamical system in which each time step corresponds to the application of one of a finite collection of maps. The maps, which represent distinct dynamical regimes, may act in some pre-determined sequence or may be applied in random order. An algorithm is developed to detect the sequence of regime switches under the assumption of continuity. This method is tested on a simple IFS and applied to an experimental computer performance data set. This methodology has a wide range of potential uses: from change-point detection in time-series data to the field of digital communications

    Phase 2 and 3 wind tunnel tests of the J-97 powered, external augmentor V/STOL model

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    Static and forward speed tests were made in a 40 multiplied by 80 foot wind tunnel of a large-scale, ejector-powered V/STOL aircraft model. Modifications were made to the model following earlier tests primarily to improve longitudinal acceleration capability during transition from hovering to wingborne flight. A rearward deflection of the fuselage augmentor thrust vector was shown to be beneficial in this regard. Other augmentor modifications were tested, notably the removal of both endplates, which improved acceleration performance at the higher transition speeds. The model tests again demonstrated minimal interference of the fuselage augmentor on aerodynamic lift. A flapped canard surface also showed negligible influence on the performance of the wing and of the fuselage augmentor

    Second-chance punitivism and the contractual governance of crime and incivility: New Labour, old Hobbes

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    The growing application of mechanisms of contractual governance to behaviour that breaches social norms, rather than the criminal law, appears to represent an ethopolitical concern with delinquent self-reform through the activation of technologies of the self. In fact, there is little empirical evidence that the contractual governance of incivility leads to such self-reform. Beneath the ideology of contractual agreement to observe social norms lies what this paper calls a ‘second-chance punitivism’ which operates to crystallise behavioural elements of the Hobbesian social contract, after breach, into a more specific form. The responsibilising and individualising properties of this form of contractual governance set the moral-ideological platform for a retributive punitivism, when the rational agents it creates fail to live up to their image, and are taken to have wasted their ‘second chance’

    EFFECTS OF ENERGY DEVELOPMENT ON AGRICULTURAL LAND VALUES

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    This paper uses multiple regression analysis to examine the effects of energy resource development on sale prices of agricultural land in western North Dakota. The findings suggest that energy resources development has exerted only modest upward pressure on agricultural land values in the northern Great Plains. The land market in this region remains dominated by active farmers who are purchasing farmland as a long-term investment, and energy development has not had a major impact on the structure of that market.Land Economics/Use, Resource /Energy Economics and Policy,

    Constraints from TcT_c and the isotope effect for MgB2_2

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    With the constraint that Tc=39T_c = 39 K, as observed for MgB2_2, we use the Eliashberg equations to compute possible allowed values of the isotope coefficient, β\beta. We find that while the observed value β=0.32\beta= 0.32 can be obtained in principle, it is difficult to reconcile a recently calculated spectral function with such a low observed value

    Optical nonlinearity enhancement of graded metallic films

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    The effective linear and third-order nonlinear susceptibility of graded metallic films with weak nonlinearity have been investigated. Due to the simple geometry, we were able to derive exactly the local field inside the graded structures having a Drude dielectric gradation profile. We calculated the effective linear dielectric constant and third-order nonlinear susceptibility. We investigated the surface plasmon resonant effect on the optical absorption, optical nonlinearity enhancement, and figure of merit of graded metallic films. It is found that the presence of gradation in metallic films yields a broad resonant plasmon band in the optical region, resulting in a large enhancement of the optical nonlinearity and hence a large figure of merit. We suggest experiments be done to check our theoretical predictions, because graded metallic films can be fabricated more easily than graded particles.Comment: 11 pages, 2 eps figures, submitted to Applied Physics Letter
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