卷 41, 编号 2 (2017)

The parallel use of the Kalman ensemble filter technique for assimilating data from observations in theHYCOMmodel of theWorldOcean is described. Data from satellite observations of the sea’s surface temperature and the sea’s surface height are assimilated both separately and conjointly. Numerical experiments on correcting model calculations using data from observations are performed. The results from the corrections are compared to model calculations without assimilation. The effectiveness of the employed parallelization algorithm is confirmed.

The effect wa ys of estimating noise variance on the statistical characteristics of the stabilized hard thresholding of signal wavelet coefficients is studied. An unbiased estimator of the mean-square risk is analyzed. It is shown that under certain conditions, the estimator distribution tends to a normal law with variance that depends on the type of noise variance estimate.

Multilinear forms over finite fields are considered. Multilinear forms over a field are products in which each factor is the sum of variables or elements of this field. Each multilinear form defines a function over this field. A multilinear form is called satisfiable if it represents a nonzero function. We show the N P-completeness of the satisfiability recognition problem for multilinear forms over each finite field of q elements for q ≥ 3. A theorem is proved that distinguishes cases of polynomiality and NP-completeness of the satisfiability recognition problem for multilinear fields for each possible q ≥ 3.

A new algorithm for aligning text with speech audio signals having lengths of up to several hours is proposed. The algorithm allows its quality to be effectively evaluated. The requirements on the acoustic model are not very demanding. The algorithm can be used to design an audio–video course for learning the Russian language.