3,459 research outputs found

    Remote sensing of earth terrain

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    Abstracts from 46 refereed journal and conference papers are presented for research on remote sensing of earth terrain. The topics covered related to remote sensing include the following: mathematical models, vegetation cover, sea ice, finite difference theory, electromagnetic waves, polarimetry, neural networks, random media, synthetic aperture radar, electromagnetic bias, and others

    Realising the open virtual commissioning of modular automation systems

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    To address the challenges in the automotive industry posed by the need to rapidly manufacture more product variants, and the resultant need for more adaptable production systems, radical changes are now required in the way in which such systems are developed and implemented. In this context, two enabling approaches for achieving more agile manufacturing, namely modular automation systems and virtual commissioning, are briefly reviewed in this contribution. Ongoing research conducted at Loughborough University which aims to provide a modular approach to automation systems design coupled with a virtual engineering toolset for the (re)configuration of such manufacturing automation systems is reported. The problems faced in the virtual commissioning of modular automation systems are outlined. AutomationML - an emerging neutral data format which has potential to address integration problems is discussed. The paper proposes and illustrates a collaborative framework in which AutomationML is adopted for the data exchange and data representation of related models to enable efficient open virtual prototype construction and virtual commissioning of modular automation systems. A case study is provided to show how to create the data model based on AutomationML for describing a modular automation system

    Automatic generation of human machine interface screens from component-based reconfigurable virtual manufacturing cell

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    Increasing complexity and decreasing time-tomarket require changes in the traditional way of building automation systems. The paper describes a novel approach to automatically generate the Human Machine Interface (HMI) screens for component-based manufacturing cells based on their corresponding virtual models. Manufacturing cells are first prototyped and commissioned within a virtual engineering environment to validate and optimise the control behaviour. A framework for reusing the embedded control information in the virtual models to automatically generate the HMI screens is proposed. Finally, for proof of concept, the proposed solution is implemented and tested on a test rig

    Superconductivity in the Nb-Ru-Ge σ\sigma-Phase

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    We show that the previously unreported ternary σ\sigma-phase material Nb20.4_{20.4}Ru5.7_{5.7}Ge3.9_{3.9} is a superconductor with a critical temperature of 2.2 K. Temperature-dependent magnetic susceptibility, resistance, and specific heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ\gamma for Nb20.4_{20.4}Ru5.7_{5.7}Ge3.9_{3.9} is 91 mJ mol-f.u.−1^{-1}K−2^{-2} and the specific heat anomaly at the superconducting transition, Δ\DeltaC/γ\gammaTc_c, is approximately 1.38. The zero-temperature upper critical field (μ0\mu_0Hc2_{c2}(0)) was estimated to be 2 T by resistance data. Field-dependent magnetization data analysis estimated μ0\mu_0Hc1_{c1}(0) to be 5.5 mT. Thus, the characterization shows Nb20.4_{20.4}Ru5.7_{5.7}Ge3.9_{3.9} to be a type II BCS superconductor. This material appears to be the first reported ternary phase in the Nb-Ru-Ge system, and the fact that there are no previously reported binary Nb-Ru, Nb-Ge, or Ru-Ge σ\sigma-phases shows that all three elements are necessary to stabilize the material. A σ\sigma-phase in the Ta-Ru-Ge system was synthesized but did not display superconductivity above 1.7 K, which suggests that electron count cannot govern the superconductivity observed. Preliminary characterization of a possible superconducting σ\sigma-phase in the Nb-Ru-Ga system is also reported.Comment: 7 pages, 8 figures, 3 table

    CEO Duality Leadership And Firm Risk-Taking Propensity

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    Based on a sample of 290 large U.S. corporations, we find that dual positioning on both CEO and board chairperson positions at the corporate top leads to reduced firm risk-taking propensity, serving managerial risk minimization preferences. We also find empirical evidence that traditionally emphasized control mechanisms of board independence and managerial ownership are ineffective in controlling managerial behavior when CEO duality leadership exists. Additionally, the power balance obtained from concentrated shareholder ownership in the firm has significant impact on controlling managerial behavior regarding firm risk taking. The findings of this research contribute to reducing the controversy surrounding CEO duality leadership by furnishing empirical evidence of how CEO duality leadership in corporate governance structure affects managerial behavior in corporate strategic management

    Application of theoretical models to active and passive remote sensing of saline ice

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    The random medium model is used to interpret the polarimetric active and passive measurements of saline ice. The ice layer is described as a host ice medium embedded with randomly distributed inhomogeneities, and the underlying sea water is considered as a homogeneous half-space. The scatterers in the ice layer are modeled with an ellipsoidal correlation function. The orientation of the scatterers is vertically aligned and azimuthally random. The strong permittivity fluctuation theory is employed to calculate the effective permittivity and the distorted Born approximation is used to obtain the polarimetric scattering coefficients. We also calculate the thermal emissions based on the reciprocity and energy conservation principles. The effects of the random roughness at the air-ice, and ice-water interfaces are accounted for by adding the surface scattering to the volume scattering return incoherently. The above theoretical model, which has been successfully applied to analyze the radar backscatter data of the first-year sea ice near Point Barrow, AK, is used to interpret the measurements performed in the CRRELEX program
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