Quasioptimal antenna array control in the problem of increasing noise immunity of information systems

Aquasioptimal method for control of antenna arrays in information-measurement systems is considered. The method is based on optimizing the form of directivity pattern of an array under complex amplitude current control in some of its elements. The advantage of the method is high-speed operation as a result of reducing expenses on calculating optimal parameters of the antenna system.     

Problems of Describing Complex Sorption Equilibria

Problems of choosing a model for describing empirical sorption data in a system consisting of an energetically nonuniform sorbent and a chemically uniform sorbate in the case when the distribution of energetically nonuniform sorption sites in the material is unknown a priori are considered. The advantages and drawbacks of choosing a sorption model adequate to the experimental data on the basis of analysis of variance are analyzed taking into account the estimated boundaries of the minimum necessary accuracy of the primary experimental data. Statistical methods do not always allow unambiguous choice of an adequate model because of limited accuracy of the experimental data. In such cases, the check of the physicochemical consequences of the model is the best argument in favor of its adequacy.     

An automatic diabetes diagnosis system based on LDA-Wavelet Support Vector Machine Classifier

In this paper, an automatic diagnosis system for diabetes on Linear Discriminant Analysis (LDA) and Morlet Wavelet Support Vector Machine Classifier: LDA–MWSVM is introduced. The structure of this automatic system based on LDA-MWSVM for the diagnosis of diabetes is composed of three stages: The feature extraction and feature reduction stage by using the Linear Discriminant Analysis (LDA) method and the classification stage by using Morlet Wavelet Support Vector Machine (MWSVM) classifier stage. The Linear Discriminant Analysis (LDA) is used to separate features variables between healthy and patient (diabetes) data in the first stage. The healthy and patient (diabetes) features obtained in the first stage are given to inputs of the MWSVM classifier in the second stage. Finally, in the third stage, the correct diagnosis performance of this automatic system based on LDA–MWSVM for the diagnosis of diabetes is calculated by using sensitivity and specificity analysis, classification accuracy, and confusion matrix, respectively. The classification accuracy of this system was obtained at about 89.74%.     

Mobile multi-view object image search

High user interaction capability of mobile devices can help improve the accuracy of mobile visual search systems. At query time, it is possible to capture multiple views of an object from different viewing angles and at different scales with the mobile device camera to obtain richer information about the object compared to a single view and hence return more accurate results. Motivated by this, we propose a new multi-view visual query model on multi-view object image databases for mobile visual search. Multi-view images of objects acquired by the mobile clients are processed and local features are sent to a server, which combines the query image representations with early/late fusion methods and returns the query results. We performed a comprehensive analysis of early and late fusion approaches using various similarity functions, on an existing single view and a new multi-view object image database. The experimental results show that multi-view search provides significantly better retrieval accuracy compared to traditional single view search.     

Stability radius of implicit dynamic equations with constant coefficients on time scales

This paper deals with the stability radii of implicit dynamic equations on time scales when the structured perturbations act on both the coefficient of derivative and the right-hand side. Formulas of the stability radii are derived as a unification and generalization of some previous results. A special case where the real stability radius and the complex stability radius are equal is studied. Examples are derived to illustrate results.     

Structure—phase transformations in contacting surface layers of coated steel during slipping friction with lubricant

Two approaches are used in simulating the thermal impact during the slipping friction of steel with lubricant, when high pressure is created and travels as an expansion—compression wave to the surface layers. This results in polymorphic transformation and anomalously fast diffusional mass transfer below the kinetic-transformation temperature. The pressure and diffusion coefficients are calculated.     

A Multivariate T2 Control Chart for Skewed Populations Using Weighted Standard Deviations

This paper proposes a heuristic method of constructing multivariate T² control charts for skewed populations based on ‘weighted standard deviations’, obtained by decomposing the standard deviation into upper and lower deviations according to the direction and degree of skewness. The proposed method adjusts the variance–covariance matrix of quality characteristics and modifies the ellipsoidal probability density function contour of the multivariate normal distribution to a shape similar to that of the skewed distribution. False alarm rates and out‐of‐control average run lengths of the proposed control chart are compared with those of the standard control chart for multivariate lognormal, Weibull and gamma distributions, and the results show that considerable improvement over the standard method can be achieved when the distribution is skewed. Copyright © 2003 John Wiley & Sons, Ltd.