We have shown recently that, when certain quite general conditions are satisfied, the set of local minima in the optical merit function space forms a network where they are all connected through optimization paths generated from saddle points having a Morse index of 1. A new global optimization method, that makes use of this linking network to systematically detect all minima, is presented. The...

Voltage stability has become one of the major concerns of many electric utilities all over the world. This paper presents an Artificial Neural Network (ANN) based model for on-line voltage stability assessment. Maximum L-index of the load buses in the system is taken as the indicator of voltage instability. Pre-contingency state power flows are taken as the input to the neural network. The key ...

Most methods of reducing the dimensionality of a data-set try to maximize the variance of the data in the lower-dimensional space; but the axes that achieve this may have no relation to the meaning of the data. We introduce a new semi-supervised method of dimensionality reduction which can embed data of high dimension in a user-defined coordinate system of lower dimension with axes that are mea...

This paper is a brief survey of the current state of the technology used in supporting eecient content-based retrieval in index-based multimedia databases that use feature vectors to represent the multimedia data. One of the main obstacles in performing eecient content-based multimedia retrieval is the high-dimensionality of the feature vectors used to characterise the data. Previous surveys on...

This work continues in development of the recently proposed Bottle-Neck features for ASR. A five-layers MLP used in bottleneck feature extraction allows to obtai arbitrary feature size without dimensionality reduction by transforms, independently on the MLP training targets. The MLP topology – number and sizes of layers, suitable training targets, the impact of output feature transforms, the ne...

The collection of abstracts of WSOM'97 articles was organized using a simpliied form of the WEBSOM method. The result ooers an approximate visual index to the workshop. The resulting map shows no clear general organizing criterion; instead the grounds for clustering certain documents seem to vary accross areas, sometimes even within a single node across pairs of articles. It is suggested that t...

In this paper, I study a number of statistical issues that arise in the formulation of stress scenarios for market risk in financial instruments. The possibility of reducing the number of scenarios through the use of data-based, statistical dimension reduction methods is explored. Using data on returns to spot exchange, stock market and interest rate products for a number of countries, I show t...

This paper provides some useful tests for fitting a parametric single-index regression model when covariates are measured with error and validation data is available. We propose two tests whose consistency rates do not depend on the dimension of the covariate vector when an adaptive-to-model strategy is applied. One of these tests has a bias term that becomes arbitrarily large with increasing s...

This paper presents the recognition method of fractal images. The approach is considered based on using support subspaces. Support subspaces are constructed with vectors of source data using a conjunction index. The proposed new computing algorithm for the conjugation index reduces requirements for computing capacities and memory. It is shown that the proposed method of construction, supporting...