1,009 research outputs found

    Grouped feature screening for ultrahigh-dimensional classification via Gini distance correlation

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    Gini distance correlation (GDC) was recently proposed to measure the dependence between a categorical variable, Y, and a numerical random vector, X. It mutually characterizes independence between X and Y. In this article, we utilize the GDC to establish a feature screening for ultrahigh-dimensional discriminant analysis where the response variable is categorical. It can be used for screening individual features as well as grouped features. The proposed procedure possesses several appealing properties. It is model-free. No model specification is needed. It holds the sure independence screening property and the ranking consistency property. The proposed screening method can also deal with the case that the response has divergent number of categories. We conduct several Monte Carlo simulation studies to examine the finite sample performance of the proposed screening procedure. Real data analysis for two real life datasets are illustrated.Comment: 25 pages, 1 figur

    A note on eigenvalues of random block Toeplitz matrices with slowly growing bandwidth

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    This paper can be thought of as a remark of \cite{llw}, where the authors studied the eigenvalue distribution ΞΌXN\mu_{X_N} of random block Toeplitz band matrices with given block order mm. In this note we will give explicit density functions of lim⁑Nβ†’βˆžΞΌXN\lim\limits_{N\to\infty}\mu_{X_N} when the bandwidth grows slowly. In fact, these densities are exactly the normalized one-point correlation functions of mΓ—mm\times m Gaussian unitary ensemble (GUE for short). The series {lim⁑Nβ†’βˆžΞΌXN∣m∈N}\{\lim\limits_{N\to\infty}\mu_{X_N}|m\in\mathbb{N}\} can be seen as a transition from the standard normal distribution to semicircle distribution. We also show a similar relationship between GOE and block Toeplitz band matrices with symmetric blocks.Comment: 6 page

    Vehicular Edge Cloud Computing: Depressurize the Intelligent Vehicles Onboard Computational Power

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    Recently, with the rapid development of autonomous vehicles and connected vehicles, the demands of vehicular computing keep continuously growing. We notice a constant and limited onboard computational ability can hardly keep up with the rising requirements of the vehicular system and software application during their long-term lifetime, and also at the same time, the vehicles onboard computation causes an increasingly higher vehicular energy consumption. Therefore, we suppose to build a vehicular edge cloud computing (VECC) framework to resolve such a vehicular computing dilemma. In this framework, potential vehicular computing tasks can be executed remotely in an edge cloud within their time latency constraints. Simultaneously, an effective wireless network resources allocation scheme is one of the essential and fundamental factors for the QoS (quality of Service) on the VECC. In this paper, we adopted a stochastic fair allocation (SFA) algorithm to randomly allocate minimum required resource blocks to admitted vehicular users. The numerical results show great effectiveness of energy efficiency in VECC.Comment: 2018 IEEE 21st International Conference on Intelligent Transportation Systems (ITSC
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