虹膜定位

为了提高虹膜定位的速度以及虹膜定位算法的健壮性,提出了一种粗定位与精定位相结合的两步定位法,用以进行虹膜定位,并对现有的虹膜定位算法进行了一些改进,实验结果表明,用两步法进行虹膜定位可以加快定位速度,减少搜索计算的盲目性。     

新的免疫细胞传感器CANARY的研究应用进展

免疫细胞传感器的出现推动了病原体检测的发展.该文综述了B淋巴细胞作为传感器敏感元件的构建,B细胞传感器的检测原理及其在病原体检测中的应用研究进展,并展望了免疫细胞传感器的潜在发展前景.     

New approach to the automatic segmentation of coronary artery in X-ray angiograms

For the segmentation of X-ray angiograms （XRA）, the essential feature and the prior knowledge of angiographic image were analyzed, and a multi-feature based fuzzy recognition （MFFR） algorithm was proposed to infer the local vessel structure in this paper. Guided by the prior knowledge of artery vessel, a probability tracking operator （PTO） can rapidly track along the artery tree, and walk across the weak region or gaps because of disturbance or preprocessing to angiographic image. Another, the accurate measurement of the vascular axis-lines and diameters can be synchronously implemented in the tracking process. To correctly evaluate the proposed method, a simulated image of CAT and some clinical XRA images were used in the experimentations. The algorithms performed better than the conventional one： given one start-point, on average 92.7% of the visible segments or branches was automatically delineated; the correctness ratio of vessel structure inference reached to 90.0% on the average.     

Performance analysis of stochastic gradient algorithms under weak conditions

By using the stochastic martingale theory, convergence properties of stochastic gradient （SG） identification algorithms are studied under weak conditions. The analysis indicates that the parameter estimates by the SG algorithms consistently converge to the true parameters, as long as the information vector is persistently exciting （i.e., the data product moment matrix has a bounded condition number） and that the process noises are zero mean and uncorrelated. These results remove the strict assumptions, made in existing references, that the noise variances and high-order moments exist, and the processes are stationary and ergodic and the strong persis- tent excitation condition holds. This contribution greatly relaxes the convergence conditions of stochastic gradient algorithms. The simulation results with bounded and unbounded noise variances confirm the convergence conclusions proposed.     

计算机视觉技术的发展及应用

计算机视觉技术集数字图像处理、数字信号处理、光学、物理学、几何学、应用数学、模式识别及人工智能等知识于一体,其应用已经涉及到计算几何、计算机图形学、图像处理、机器人学等领域。文中简要地回顾了计算机视觉技术的发展史,主要介绍了计算机视觉中图像处理技术在检测技术方面的应用。利用工业摄像镜头替代目视作为传感器,通过图像采集,图像处理,图像识别等一系列操作,达到在线对包装产品进行标签检测的目的。     

Web日志挖掘的数据预处理研究

数据预处理在Web日志挖掘过程中起着至关重要的作用。本文详细分析了数据预处理的过程,并对用户识别提出了改进策略,最后实现了一个Web日志挖掘预处理模型(WLMPM)。     

基于双约简的GMM说话人辨识

如何能够快速准确的实现说话人识别是说话人识别研究的一个重要环节。提出双约简GMM的说话人确认方法,对语音参数进行核K-均值聚类,提取聚类中心的语音特征矢量作为训练数据,并对其进行fisher比约简,提取具有区分力强的维数。实验表明该文提取方法可以减少训练时间,并提高系统的鲁棒性。     

Robust H∞ control of uncertain linear impulsive stochastic systems

This paper develops robust stability theorems and robust H_∞ control theory for uncertain impulsive stochastic systems. The parametric uncertainties are assumed to be time varying and norm bounded. Impulsive stochastic systems can be divided into three cases, namely, the systems with stable/stabilizable continuous‐time stochastic dynamics and unstable/unstabilizable discrete‐time dynamics, the systems with unstable/unstabilizable continuous dynamics and stable/stabilizable discrete‐time dynamics, and the systems in which both the continuous‐time stochastic dynamics and the discrete‐time dynamics are stable/stabilizable. Sufficient conditions for robust exponential stability and robust stabilization for uncertain impulsive stochastic systems are derived in terms of an average dwell‐time condition. Then, a linear matrix inequality‐based approach to the design of a robust H_∞ controller for each system is presented. Finally, the numerical examples are provided to demonstrate the effectiveness of the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.     

Delay‐dependent robust stability for stochastic time‐delay systems with polytopic uncertainties

This paper considers a delay‐dependent and parameter‐dependent robust stability criterion for stochastic time‐delay systems with polytopic uncertainties. The delay‐dependent robust stability criterion, as expressed in terms of linear matrix inequalities (LMIs), is obtained by using parameter‐dependent Lyapunov functions. It is shown that the result derived by a parameter‐dependent Lyapunov functional is less conservative. Numerical examples are provided to illustrate the effectiveness of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.     

Analyzing the structure of a class of linear automata over a ring $$ Z_{p^k } $$

Basic finite-automaton characteristics are established for the class of all linear automata and information-lossless automata over a ring. The complexities of solving problems of parametric identification and initial-state identification are analyzed. The sets of fixed points for mappings realized by initial automata are characterized. Canonical forms are proposed for linear automata over the ring. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 60–74, May–June 2008.