147,129 research outputs found
3D inference and modelling for video retrieval
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
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
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 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
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
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
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
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
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
- âŠ