3,332 research outputs found
Enhanced spin injection efficiency in a four-terminal double quantum dot system
Within the scheme of quantum rate equations, we investigate the spin-resolved
transport through a double quantum dot system with four ferromagnetic
terminals. It is found that the injection efficiency of spin-polarized
electrons can be significantly improved compared with single dot case. When the
magnetization in one of four ferromagnetic terminals is antiparallel with the
other three, the polarization rate of the current through one dot can be
greatly enhanced, accompanied by the drastic decrease of the current
polarization rate through the other one. The mechanism is the exchange
interaction between electrons in the two quantum dots, which can be a promising
candidate for the improvement of the spin injection efficiency.Comment: 10 pages and 5 figure
Polyadic Constacyclic Codes
For any given positive integer , a necessary and sufficient condition for
the existence of Type I -adic constacyclic codes is given. Further, for any
given integer , a necessary and sufficient condition for to be a
multiplier of a Type I polyadic constacyclic code is given. As an application,
some optimal codes from Type I polyadic constacyclic codes, including
generalized Reed-Solomon codes and alternant MDS codes, are constructed.Comment: We provide complete solutions on two basic questions on polyadic
constacyclic cdes, and construct some optimal codes from the polyadic
constacyclic cde
HOS-Miner: a system for detecting outlying subspaces of high-dimensional data
[Abstract]: We identify a new and interesting high-dimensional outlier detection problem in this paper that is, detecting the subspaces in which given data points are outliers. We call the subspaces in which a data point is an outlier as its Outlying Subspaces. In this paper, we will propose the prototype of a dynamic subspace search system, called HOS-Miner (HOS stands for High-dimensional Outlying Subspaces) that utilizes a sample-based learning process to effectively identify the outlying subspaces of a given point
Designs of low delay cosine modulated filter banks and subband amplifiers
This paper proposes a design of a low delay cosine modu-lated filter bank and subband amplifier coefficients for digi-tal audio hearing aids denoising applications. The objective of the design is to minimize the delay of the filter bank. Speci-fications on the maximum magnitude of both the real and the imaginary parts of the transfer function distortion and the aliasing distortion of the filter bank are imposed. Also, the constraint on the maximum absolute difference between the desirable magnitude square response and the designed mag-nitude square response of the prototype filter over both the passband and the stopband is considered. The subband am-plifier coefficients are designed based on a least squares training approach. The average mean square errors between the noisy samples and the clean samples is minimized. Com-puter numerical simulation results show that our proposed approach could significantly improve the signal-to-noise ratio of digital audio hearing aids
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