Simple and fast convergent procedure to estimate recursive path analysis model

Behaviormetrika - BFGS procedure is classically used for the estimation of the parameters of a recursive Path Analysis model. In practice, BFGS does not present any problem of convergence. However,...     

High gain observer based on-line rotor and stator resistances estimation for IMs

One of the main challenging issues in induction motor drives is the lack of knowledge about the actual values of some critical parameters, such as rotor and stator resistances which are subject to large variations during operation. Such problem is difficult to resolve due to the strong interconnection between states and parameters in the nonlinear motor model, besides the unavailability of both rotor flux and load torque. In the spirit to accurately follow the on-line machine variables, this paper focuses on the simultaneous estimation of internal states and time varying parameters. Especially, a new identification scheme for rotor resistance and/or stator resistance is introduced. In the aim of decoupling the unknown electrical parameters, we adopt a mild change of coordinates that allows to easily design a two-stage of high gain observer. The simplicity of presented procedures and the efficiency for real time computation constitute both main features of the proposed approach. Moreover, possible exploitation of our algorithm in the fault detection issue is discussed through a simulation of an abrupt rotor short-circuit.     

一种用于说话人头部动画的Viseme语音识别系统

Viseme是在语音驱动说话人头部动画中一种常用的为口形建立的音频-视频模型。本文尝试建立viseme隐马尔可夫模型(HMM)，用于驱动说话人头部的语音识别系统，称为前映射系统。为了得到更精确的模型以提高识别率，引入考虑发音口形上下文的Triseme模型。但是引入Triseme模型后，随着模型数量的急剧增加将导致训练数据的严重不足。本文使用决策树状态捆绑方法来缓解这一问题，同时引入了一种以口形相似度为基础的决策树视频问题设计方法。为了比较viseme系统的性能，本文也建立了一个以phoneme为基本HMM模型的语音识别系统。在评价准则上，使用了一种客观评价说话人头部动画的加权识别率。实验表明，以viseme为基本HMM模型的前映射系统可以为说话人头部提供更加合理的口形。     

一种基于数据筛的音频视频连续语音识别系统

文中考虑语音的音频和视频双模型特性，建立了一个在噪音环境下的基于音频和视频复合特征的连续语音识别系统。在视频特征提取方面，引入了一种鲁棒性较好的数据筛特征提取方法：在音频和视频集成建模方面，使用多数据流HMM来反映语音的双模型特性。识别实验表明，文中建立的音频视频连续语音识别系统具有很好的抗噪性。     

Scale Selection for Compact Scale-Space Representation of Vector-Valued Images

This paper investigates the scale selection problem for nonlinear diffusion scale-spaces. This topic comprises the notions of localization scale selection and scale space discretization. For the former, we present a new approach. It aims at maximizing the image content’s presence by finding the scale that has a maximum correlation with the noise-free image. For the latter, we propose to adapt the optimal diffusion stopping time criterion of Mrázek and Navara in such a way that it may identify multiple scales of importance.     

Stress intensity solutions for cracked plates by the dual boundary method

We describe the application of the dual boundary element method for the determination of stress intensity factors in plate bending problems. The loadings considered include internal pressure, and also combined bending and tension. Mixed mode stress intensity factors are evaluated by a crack surface displacement extrapolation technique and the J-integral technique. The boundary element results for the case studies considered in the paper have been compared with either analytical or finite element results and in all cases good agreement has been achieved. __________ Translated from Problemy Prochnosti, No. 5, pp. 81–93, September–October, 2007.     

A model-based approach to the automatic extraction of linearfeatures from airborne images

The authors describe a model-based method for the automatic extraction of linear features, like roads and paths, from aerial images. The paper combines and extends two earlier approaches for road detection in SAR satellite images and presents the modifications needed for the application domain of airborne image analysis together with representative results