38,992 research outputs found

    Cylindrical Superlens by a Coordinate Transformation

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    Cylinder-shaped perfect lens deduced from the coordinate transformation method is proposed. The previously reported perfect slab lens is noticed to be a limiting form of the cylindrical lens when the inner radius approaches infinity with respect to the lens thickness. Connaturality between a cylindrical lens and a slab lens is affirmed by comparing their eigenfield transfer functions. We numerically confirm the subwavelength focusing capability of such a cylindrical lens with consideration of material imperfection. Compared to a slab lens, a cylindrical lens has several advantages, including finiteness in cross-section, and ability in lensing with magnification or demagnification. Immediate applications of such a cylindrical lens can be in high-resolution imaging and lithography technologies. In addition, its invisibility property suggests that it may be valuable for non-invasive electromagnetic probing.Comment: Minor changes to conform with the published versio

    Mott physics in 2p2p electron dioxygenyl magnet : O2_{2}MMF6_{6} (MM=Sb, Pt)

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    We have investigated electronic structures and magnetic properties of O2_{2}MMF6_{6} (MM=Sb, Pt), which are composed of two building blocks of strongly correlated electrons: O2+_{2}^{+} dioxygenyls and MMF6_{6}^{-} octahedra, by employing the first-principles electronic structure band method. For O2_{2}SbF6_{6}, as a reference system of O2_{2}PtF6_{6}, we have shown that the Coulomb correlation of O(2pp) electrons drives the Mott insulating state. For O2_{2}PtF6_{6}, we have demonstrated that the Mott insulating state is induced by the combined effects of the Coulomb correlation of O(2pp) and Pt(5dd) electrons and the spin-orbit (SO) interaction of Pt(5dd) states. The role of the SO interaction in forming the Mott insulating state of O2_{2}PtF6_{6} is similar to the case of Sr2_{2}IrO4_{4} that is a prototype of a SO induced Mott system with Jeff=1/2_{eff}=1/2.Comment: 5 pages, 6 figure

    ARDL Modelling Approach to Testing the Financial Liberalisation Hypothesis

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    It is a stylised fact that financial "repression" retards economic growth. Hence, financial liberalisation is advocated to remove the stranglehold on the economy. Financial liberalisation policy argues that deregulation of interest rate would result into a higher real interest rate which would lead to increased savings, increased investment and achieve efficiency in financial resource allocation. Past studies have reported inconclusive results regarding the interest rate effects on savings and investment. This paper examines the financial liberalisation hypothesis by employing autoregressive distributed lag (ARDL) modelling approach on Nepalese data. Results show that the real interest rate affects both savings and investment positively.Financial Liberalisation, Interest Rate Effects, Unit Roots, Cointegration, ARDL Modelling

    A text-based approach to the ImageCLEF 2010 photo annotation task

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    The challenges of searching the increasingly large collections of digital images which are appearing in many places mean that automated annotation of images is becoming an important task. We describe our participation in the ImageCLEF 2010 Visual Concept Detection and Annotation Task. Our approach used only the textual features (Flickr user tags and EXIF information) to perform the automatic annotation. Our approach was to explore the use of different techniques to improve the results of textual annotation. We identify the drawbacks of our approach and how these might be addressed and optimized in further work
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