70,079 research outputs found
Note: An object detection method for active camera
To solve the problems caused by a changing background during object detection in active camera, this paper proposes a new method based on SURF (speeded up robust features) and data clustering. The SURF feature points of each image are extracted, and each cluster center is calculated by processing the data clustering of k adjacent frames. Templates for each class are obtained by calculating the histograms within the regions around the center points of the clustering classes. The window of the moving object can be located by finding the region that satisfies the histogram matching result between adjacent frames. Experimental results demonstrate that the proposed method can improve the effectiveness of object detection.Yong Chen, Ronghua Zhang, Lei Shang, and Eric H
A New HDG Method for Dirichlet Boundary Control of Convection Diffusion PDEs II: Low Regularity
In the first part of this work, we analyzed a Dirichlet boundary control
problem for an elliptic convection diffusion PDE and proposed a new
hybridizable discontinuous Galerkin (HDG) method to approximate the solution.
For the case of a 2D polygonal domain, we also proved an optimal superlinear
convergence rate for the control under certain assumptions on the domain and on
the target state. In this work, we revisit the convergence analysis without
these assumptions; in this case, the solution can have low regularity and we
use a different analysis approach. We again prove an optimal convergence rate
for the control, and present numerical results to illustrate the convergence
theory
Entangling photons using a charged quantum dot in a microcavity
We present two novel schemes to generate photon polarization entanglement via
single electron spins confined in charged quantum dots inside microcavities.
One scheme is via entangled remote electron spins followed by
negatively-charged exciton emissions, and another scheme is via a single
electron spin followed by the spin state measurement. Both schemes are based on
giant circular birefringence and giant Faraday rotation induced by a single
electron spin in a microcavity. Our schemes are deterministic and can generate
an arbitrary amount of multi-photon entanglement. Following similar procedures,
a scheme for a photon-spin quantum interface is proposed.Comment: 4 pages, 4 figure
The entanglement beam splitter: a quantum-dot spin in a double-sided optical microcavity
We propose an entanglement beam splitter (EBS) using a quantum-dot spin in a
double-sided optical microcavity. In contrast to the conventional optical beam
splitter, the EBS can directly split a photon-spin product state into two
constituent entangled states via transmission and reflection with high fidelity
and high efficiency (up to 100 percent). This device is based on giant optical
circular birefringence induced by a single spin as a result of cavity quantum
electrodynamics and the spin selection rule of trion transition (Pauli
blocking). The EBS is robust and it is immune to the fine structure splitting
in a realistic quantum dot. This quantum device can be used for
deterministically creating photon-spin, photon-photon and spin-spin
entanglement as well as a single-shot quantum non-demolition measurement of a
single spin. Therefore, the EBS can find wide applications in quantum
information science and technology.Comment: 7 pages, 5 figure
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