4,686 research outputs found

    Content vs. context for multimedia semantics: the case of SenseCam image structuring

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    Much of the current work on determining multimedia semantics from multimedia artifacts is based around using either context, or using content. When leveraged thoroughly these can independently provide content description which is used in building content-based applications. However, there are few cases where multimedia semantics are determined based on an integrated analysis of content and context. In this keynote talk we present one such example system in which we use an integrated combination of the two to automatically structure large collections of images taken by a SenseCam, a device from Microsoft Research which passively records a personā€™s daily activities. This paper describes the post-processing we perform on SenseCam images in order to present a structured, organised visualisation of the highlights of each of the wearerā€™s days

    Notes on two-parameter quantum groups, (II)

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    This paper is the sequel to [HP1] to study the deformed structures and representations of two-parameter quantum groups Ur,s(g)U_{r,s}(\mathfrak{g}) associated to the finite dimensional simple Lie algebras \mg. An equivalence of the braided tensor categories \O^{r,s} and \O^{q} is explicitly established.Comment: 21 page

    Improving Cavity Enhanced Spectroscopy of Molecular Ions in the Mid-Infrared With Up-Conversion Detection and Brewster-Plate Spoilers

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    The performance of sensitive spectroscopic methods in the mid-IR is often limited by fringing due to parasitic etalons and the background noise in mid-infrared detectors. In particular, the technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS), which is capable of determining the frequencies of strong rovibrational transitions of molecular ions with sub-MHz uncertainty, needs improved sensitivity in order to probe weaker transitions. In this work, we have implemented up-conversion detection with NICE-OHVMS in the 3.2 - 3.9 Ī¼m region to enable the use of faster and more sensitive detectors which cover visible wavelengths. The higher bandwidth enabled detection at optimized heterodyne frequencies, which increased the overall signal from the H43 cation by a factor of three and was able to resolve sub-Doppler features which had previously overlapped. Also, we demonstrate the effectiveness of Brewster-plate spoilers to remove fringes due to parasitic etalons in a cavity enhanced technique. Together, these improvements reduced the instrument\u27s noise equivalent absorption to 5.9 X 10-11 cm-1 Hz-1/2, which represents a factor of 34 improvement in sensitivity compared to previous implementations of NICE-OHVMS. This work will enable extended high-precision spectroscopic surveys of H43 and other important molecular ions
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