In the article we consider a method of labeling speaker data using clusterization techniques. Such problems arise when one needs to use speaker data from new channels, for example, mobile devices. These data might then be used to construct a speaker verification system. In the article described a speaker verification task along with some methods to solve it which are based on GMM – UBM, also some channel normalization techniques are described, which might enhance the quality of recognition. Methods based on supervectors and PLDA are described. We also study quality of labeling obtained through clusterization with different metrics. Resulting labelled data is then used to train several PLDA models. Obtained models then fused and used to solve a speaker verification task on i-vectors from NIST i-vector Machine Learning Challenge 2014.
Unstable reverse zones in free supersonic jets is discovered numerically using finite-volume flow solver. Reverse zones may observe behind the Mach disk as in first so and second cells of underexpanded jets and in second cell of overexpanded jets. It's determined the region of reverse origin in Mach number-expansion ratio plane by some initial and others conditions. Part of this region is corresponded to supersonic reverse with own shock structure. All testes as well as similar to experiment centerline contrary pressure gradient in reverse sector is confirmed possibility such physical phenomenon.
An attempt to merge into a single model, which reduces to the solution of non-smooth convex optimization problem: calculation model of OD-matrix (entropy model), the mode split model and the model of the equilibrium distribution of flows (Stable dynamic model, Nesterov - de Palma, 2003). To best of our knowledge, this is the first attempt to combine this three models. Previously such attempts were done for other types of equlibrium models, mainly with the BMW-model (1955), the calibration of which is significantly more difficult. We also remark, that our model much better then traditional from computational point of view.
Model allowing analytical and numerical studying of dusty plasma system is used to describe dynamics of monolayer of dusty particles. Mechanism of energy transfer between horizontal and vertical particles motion based on parametric resonance is described by an extended Mathieu equation. Resonance regions and growth rates of dust particles energy are obtained. Conditions of resonance occurrence and initial stage of energy transfer are described more precisely based on analysis of derived data. It is shown that a wide spectrum of dust particles oscillations participate in energy transfer. The core harmonics of energy transfer are determined.
We present compact difference scheme on three-point stencil for unknown function. The scheme approximates linear second order differential equation with variable smooth coefficient. Our numerical experiments confirmed 4-th accuracy order of solutions of the difference scheme and of eigenvalues’ approximation for the boundary problem. The difference operator is almost self-conjugate, and its spectrum is real. The Richardson extrapolation method improves the accuracy order.
We consider a problem of stabilization of linear stochastic control systems. The quadratic cost functional measures the total loss resulting from deviation of the process and control from their target levels. It includes the decision maker’s time preference expressed by means of discount function. We study the long-run impacts of average optimal policies in terms of mean-square deviation of optimal trajectory from its target and also in an almost-sure sense.
Balanced growth paths are typical research subjects for models of macroeconomic dynamics. Balanced growth paths are model solutions that assume constant policy parameters (such as tax rate) and allow for monotonous and proportional growth of model components. In this paper, we construct and test a model with policy switching based on economic retrospective voting: the model allows to switch parties in office if an electorally important indicator exhibits decline. A change of ruling party brings about a change in policy. If the second party is then voted out of the office, the system experiences endogenous policy switching. Within this framework, we introduce the term "cyclically balanced growth paths", i.e. non-monotonous solutions where the proportionality of components is broken and then restored every political cycle. We conduct the analysis using differential equations theory and numerical experiments
The plasma contactor model is described. The length of effective collection radius for electric current, the current limit and the nessesary potential difference are culculated in the case of spherical symmetry. The magnetic field influence on the collection radius length is analised. For the plane perpendecular to the magnetic field the calculation of plasma cloud parameters on the base of one-dimensional model is fulfilled.