Analysis and Filtration of Special Discrete-Time Markov Processes. II. Optimal Filtration

Mean-square optimal filtration of the states of a special Markov process, which is the generalization of Markov chains with a finite or denumerable number of states, is studied. By way of example, tracking of the state of a network connection under TCP is given.__________Translated from Avtomatika i Telemekhanika, No. 7, 2005, pp. 112–125.Original Russian Text Copyright © 2005 by Borisov, Miller.This work was supported by INTAS, project no. YSF 04-83-3623.     

Neutron analysis of the ITER vertical neutron camera

The neutron fields in the collimators of a new design for the vertical neutron camera (VNC) of the ITER have been calculated for a standard isotropic bulk DT neutron source. The neutron and gamma-ray spectra and flux densities at the neutron detector sites have been calculated. The signal-to-background ratio of VNC detectors (²³⁸U-based fission chambers and diamond detectors) has been estimated. The signal-to-background ratios versus the threshold energy were calculated for the diamond detectors operating in the threshold counter mode. The effect of background Γ-ray radiation on the performance of the diamond detectors in the VNC environment has been estimated. The radiation heating of the VNC structural components has been calculated. The serviceability of the VNC with the proposed design has been demonstrated.     

Edible mushroom (Agaricus bisporus) lectin, which reversibly inhibits epithelial cell proliferation, blocks nuclear localization sequence-dependent nuclear protein import

The Galbeta1-3GalNAcalpha (TF antigen)-binding lectin (ABL) from the common edible mushroom (Agaricus bisporus) has a potent anti-proliferative effect without any apparent cytotoxicity. This unusual combination of properties prompted investigation of its mechanism of action. In contrast to soluble lectin, agarose-immobilized, and hence noninternalizable ABL had no effect on proliferation of HT29 colon cancer cells. Electron microscopy of HT29 cells incubated with fluorescein- and gold-conjugated ABL showed internalization of the lectin into endocytotic vesicles and multivesicular bodies. Confocal microscopy showed perinuclear accumulation of fluorescein isothiocyanate-conjugated lectin, which also inhibits HT29 cell proliferation, raising the possibility that the lectin might interfere with nuclear pore function. Transport of heat shock protein 70 into the nucleus in response to heat shock was blocked by preincubation of HT29 cells for 6 h with 40 micrograms/ml ABL. In digitonin-permeabilized cells, nuclear uptake of bovine albumin conjugated to a nuclear localization sequence (NLS)-containing peptide was also inhibited by a 15-min preincubation with 40-100 micrograms/ml ABL. In contrast, serum-stimulated nuclear translocation of mitogen-activated protein kinase, which is NLS-independent, was not affected by pretreatment of cells with the lectin. These results suggest that the anti-proliferative effect of ABL is likely to be a consequence of the lectin trafficking to the nuclear periphery, where it blocks NLS-dependent protein uptake into the nucleus.     

Modelling functioning of an adaptive industrial robot in arc welding

Steels with elasticity limits between 650 and 680 MPa include thermomechanical steels and quenched and tempered steels. Thermomechanical steels have excellent weldability, but, nevertheless, require fillers with low diffusible H₂ levels, and a rigorous control over the welding operations, due to the molten zone. Quenched and tempered steels require almost automatic recourse to preheating, and frequently post-heating, but at moderate temperatures. The heterogeneity of the commercial range of base metals available, and the poverty of the range of filler materials with very high elasticity limits, are crucial problems. The risk of cold cracking in the molten zone is very high and, sadly, less well understood than that of cold cracking in the HAZ. Given that the maintenance of good mechanical characteristics requires limiting the T _r 800–500, the weldability range is very narrow. The welding of these steels is not intrinsically complex, but requires considerable rigour.     

Optimal estimates for the operating parameters of an information web portal

We consider the problems of state estimation and Bayesian parameter identification for a stochastic model of an observation system that describes the evolution of one parameter of a web portal. Based on the thread pool control process analysis, we offer a mathematical model for the oscillations of the operating parameters for the portal’s information sources as a nonlinear stochastic observation system of a special kind. We obtain solutions of the optimal estimation problem and give numerical results.     

Efficient estimation of generator instability characteristics in the time domain

This paper considers the problem of determining the true (nonsampling) variance of the Allan parameter-the main frequency instability characteristic of frequency generators, synthesizer, and standards in the time domain. The variables influencing the efficiency of estimating the parameter are determined and compared in magnitude. For frequency fluctuations with flicker noise power-law power spectral density, the parameter estimate accuracy is most significantly affected by the variance of the estimated average frequency—the quantity included in the Allan parameter and defining the quality of averaging over a finite time interval.