148,741 research outputs found

    3D inference and modelling for video retrieval

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    A new scheme is proposed for extracting planar surfaces from 2D image sequences. We firstly perform feature correspondence over two neighboring frames, followed by the estimation of disparity and depth maps, provided a calibrated camera. We then apply iterative Random Sample Consensus (RANSAC) plane fitting to the generated 3D points to find a dominant plane in a maximum likelihood estimation style. Object points on or off this dominant plane are determined by measuring their Euclidean distance to the plane. Experimental work shows that the proposed scheme leads to better plane fitting results than the classical RANSAC method

    Feature extraction for speech and music discrimination

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    Driven by the demand of information retrieval, video editing and human-computer interface, in this paper we propose a novel spectral feature for music and speech discrimination. This scheme attempts to simulate a biological model using the averaged cepstrum, where human perception tends to pick up the areas of large cepstral changes. The cepstrum data that is away from the mean value will be exponentially reduced in magnitude. We conduct experiments of music/speech discrimination by comparing the performance of the proposed feature with that of previously proposed features in classification. The dynamic time warping based classification verifies that the proposed feature has the best quality of music/speech classification in the test database

    Large Momenta Fluctuations Of Charm Quarks In The Quark-Gluon Plasma

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    We show that large fluctuations of D mesons kinetic energy (or momentum) distributions might be a signature of a phase transition to the quark gluon plasma (QGP). In particular, a jump in the variance of the momenta or kinetic energy, as a function of a control parameter (temperature or Fermi energy at finite baryon densities) might be a signature for a first order phase transition to the QGP. This behaviour is completely consistent with the order parameter defined for a system of interacting quarks at zero temperature and finite baryon densities which shows a jump in correspondance to a first order phase transition to the QGP. The J/ΚJ/\Psi shows exactly the same behavior of the order parameter and of the variance of the D mesons. We discuss implications for relativistic heavy ion collisions within the framework of a transport model and possible hints for experimental data.Comment: 4 pages 3 figure

    Outage Probability of Wireless Ad Hoc Networks with Cooperative Relaying

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    In this paper, we analyze the performance of cooperative transmissions in wireless ad hoc networks with random node locations. According to a contention probability for message transmission, each source node can either transmits its own message signal or acts as a potential relay for others. Hence, each destination node can potentially receive two copies of the message signal, one from the direct link and the other from the relay link. Taking the random node locations and interference into account, we derive closed-form expressions for the outage probability with different combining schemes at the destination nodes. In particular, the outage performance of optimal combining, maximum ratio combining, and selection combining strategies are studied and quantified.Comment: 7 pages; IEEE Globecom 201

    Automatic human face detection for content-based image annotation

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    In this paper, an automatic human face detection approach using colour analysis is applied for content-based image annotation. In the face detection, the probable face region is detected by adaptive boosting algorithm, and then combined with a colour filtering classifier to enhance the accuracy in face detection. The initial experimental benchmark shows the proposed scheme can be efficiently applied for image annotation with higher fidelity

    Nonlinear coupling of nano mechanical resonators to Josephson quantum circuits

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    We propose a technique to couple the position operator of a nano mechanical resonator to a SQUID device by modulating its magnetic flux bias. By tuning the magnetic field properly, either linear or quadratic couplings can be realized, with a discretely adjustable coupling strength. This provides a way to realize coherent nonlinear effects in a nano mechanical resonator by coupling it to a Josephson quantum circuit. As an example, we show how squeezing of the nano mechanical resonator state can be realized with this technique. We also propose a simple method to measure the uncertainty in the position of the nano mechanical resonator without quantum state tomography

    Distinct Role of IL-27 in Immature and LPS-Induced Mature Dendritic Cell-Mediated Development of CD4

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    Interleukin-27 (IL-27) plays an important role in regulation of anti-inflammatory responses and autoimmunity; however, the molecular mechanisms of IL-27 in modulation of immune tolerance and autoimmunity have not been fully elucidated. Dendritic cells (DCs) play a central role in regulating immune responses mediated by innate and adaptive immune systems, but regulatory mechanisms of DCs in CD4+ T cell-mediated immune responses have not yet been elucidated. Here we show that IL-27 treated mature DCs induced by LPS inhibit immune tolerance mediated by LPS-stimulated DCs. IL-27 treatment facilitates development of the CD4+ CD127+3G11+ regulatory T cell subset in vitro and in vivo. By contrast, IL-27 treated immature DCs fail to modulate development of the CD4+CD127+3G11+ regulatory T cell sub-population in vitro and in vivo. Our results suggest that IL-27 may break immune tolerance induced by LPS-stimulated mature DCs through modulating development of a specific CD4+ regulatory T cell subset mediated by 3G11 and CD127. Our data reveal a new cellular regulatory mechanism of IL-27 that targets DC-mediated immune responses in autoimmune diseases such as multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). © 2018 Zhou, Zhang and Rostami

    Effect of the attachment of ferromagnetic contacts on the conductivity and giant magnetoresistance of graphene nanoribbons

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    Carbon-based nanostructures and graphene, in particular, evoke a lot of interest as new promising materials for nanoelectronics and spintronics. One of the most important issue in this context is the impact of external electrodes on electronic properties of graphene nanoribbons (GNR). The present theoretical method is based on the tight-binding model and a modified recursive procedure for Green's functions. The results show that within the ballistic transport regime, the so called end-contacted geometry (of minimal GNR/electrode interface area), is usually more advantageous for practical applications than its side-contacted counterpart (with a larger coverage area), as far as the electrical conductivity is concerned. As regards the giant magnetoresistance coefficient, however, the situation is exactly opposite, since spin- splitting effects are more pronounced in the lower conductive side-contacted setups.Comment: 8 pages, 4 figure
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