The error variance of LMS with time-varying weights

A calculation of weight error variance of the LMS (least mean square) algorithm is made in the presence of time-varying true weights. With time-varying weights the LMS error system has in general several time scales operating at once. This causes difficulties in the variance calculation which seem hitherto to have passed unnoticed. To handle this problem a sort of perturbation expansion is developed based on weak convergence methods or `stochastic averaging'. The main concern in carrying out the error variance calculation is to study the effect on LMS performance of adaptation speed as it relates to true speed of parameter change. Three cases are covered with reference to considering adaptation speed with respect to true speed: first, where the adaptation speed is too slow; second, where it is matched: and third, where it is faster     

Analytic investigation of the process of formation of a spatially inhomogeneous structural state in a steel plate subjected to rapid cooling

We analyze the process of formation of a spatially inhomogeneous phase composition of several types of steel in cooling with convective heat exchange with the environment. The principles of the classical theory of heat conduction and the theory of interpolational models of structural state formation in rapidly cooled steels are used for numerical prediction. On this basis, we develop a technique for the analysis of phase composition. It is shown that the percentage of the martensitic constituent in steels increases as the external heat removal becomes more intense; at the same time, the tendency to complete hardening in steel is intensified. These observations are in a good agreement with experiment.Pidstrygach Institute of Applied Problems in Mechanics and Mathematics, Ukrainian Academy of Sciences, L'viv. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 29, No. 6, pp. 101–104, November–December, 1993.     

Numerical electromagnetic simulator termination de-embeddingtechnique

The authors report a novel approach whereby transmission-line end effects can be assessed by numerical simulation without recourse to the evaluation of the propagation properties of the line interconnecting the termination and excitation signal launch planes. As an example of the new technique, a microstrip open-ended line termination simulated by the finite-difference time-domain method is reported. The simulated results are compared with those obtained for the same structure but by a conventional numerical de-embedding scheme. The method presented is completely general and can be applied to any numerical electromagnetic field simulation method solving one-port or multiport networks     

Monitoring water quality in reservoirs with IRS-1A-LISS-I

An attempt has been made to quantify the relationship between the variation in IRS-IA-LISS-I (Indian Remote Sensing Satellite-1A Linear Imaging Self-Scanning System) radiance data and field measured change in secchi disc depth. Secchi disc depth was measured for 47 predetermined sampling locations on reservoir surface water. At extinction depth (secchi depth), water samples were collected from all the sampling locations. Suspended sediments of eight locations representing various reaches of the reservoir were selected for mineralogical, particle size and optical properties analysis. The LISS-I radiance value in band 1 (0.45–0.52µm) band 2 (0-52–0.59 µm) and band 3 (0.62–0.68 µm) were used in a regression analysis. The absorption infrared band 4 (0.77–0.86 µm) was not included in the analysis. In these, the dependable variable was secchi depth (SD) and the LISS-I-radiance data was the estimator variable. Forty-seven data sets of 20 October 1988 from Tawa reservoir surface water were used to obtain an estimator equation for SD. The verification of the estimator equation was tested by applying it to a data set of 21 measurements of 28 September 1988 for this reservoir. The coefficient of correlation between observed and estimated values for the 28 September 1988 data set wasr=0.92 for SD, indicating that the equation could accurately predict the water clarity (SD) for this reservoir on new occasions from IRS-IA-LISS-I spectral data. It is shown that mineral composition and optical properties of suspended sediments influence the reflected radiance of water quality. It is concluded that IRS-IA-LISS-I data provide a useful means of mapping water quality in reservoir.     

Improvement of the anticorrosive properties of galvanic metallic coatings

We analyze various possibilities for improving the anticorrosive properties of metallic coatings, including alloying, modification of the base (prior to coating), the choice of the optimum (for producing anticorrosive structures) conditions of electrolysis, the use of multilayer coatings (sandwich-type structures), and modification of coatings by depositing passive layers by high-energy treatment (laser, electron-beam, plasmachemical, etc.).Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 5, pp. 81–87, September – October, 1994.     

Intelligent scheduling processes and controlling workload in computing systems

Methods and algorithms of adaptive scheduling processes and workload control in computing systems are considered.