arXiv subjects

Dmitri Volchenkov

Publications and source records attributed to Dmitri Volchenkov.

5 recordsLinked to original sources

arXiv2003

Core Lexicon and Contagious Words

We present the new empirical parameter $f_c$, the most probable usage frequency of a word in a language, computed via the distribution of documents over frequency $x$ of the word. This parameter allows for filtering the core lexicon of a language from the content words, which tend to be extremely frequent in some texts written in specific genres or by certain authors. Distributions of documents over frequencies for such words display long tails as $x>f_c$ representing a bunch of documents in which such words are used in abundance. Collections of such documents exhibit a percolation like phase transition as the coarse grain of frequency $Δf$ (flattening out the strongly irregular frequency data series) approaches the critical value $f_c$.

cond-mat.dis-nn↗

arXiv1999

Instanton solutions in the problem of wrinkled flame front dynamics

The statistics of wrinkling flame front is invetigated by the quantum filed theory methods. We dwell on the WKB approximation in the functional integral which is analogous to the Wyld functional integral in turbulence. The main contribution to statistics is due to a coupled field-force configuration. This configuration is related to a kink between metastable exact pole solutions of the Syvashinsky equation. These kinks are responsible for both the formation of new cusps and the rapid power-law acceleration of the mean flame-front. The problem of asymptotic stability of the solutions is discussed.

patt-sol↗

arXiv1999

Critical Behavior of the Water Coupled to a Local External Perturbation

The response of inviscid incompressible unbounded fluid subject to a localized external perturbation is studed. The physically relevant hypotheses on the mode coupling mechanisma is justified by renormalization group method. The scaling laws for the scalar and vector velocity potentials are derived. The spectrum of energy of perturbed fluid versus the distance apart from perturbation is computed.

physics.flu-dyn↗

arXiv1999

A Phase Transistion in the Water Coupled to a Local External Perturbation

A flux of ideal fluid coupled to perturbation is investigated by nonperturbative methods of the quantum field theory. Asymptotic behavior of the flux coupled to perturbation turns out to be similiar to that of superfluids.

physics.flu-dyn↗

arXiv1999

Renormalization Group Approach to the Problem of Flow Through Irregular Packed Beds

We have calculated the asymptotics of Green's function of the differential equation of nonlinear diffusion in the microscopic range with strong porosity fluctuations in the problem of flow through irregular packed beds for arbitrary space dimension and arbitrary covariance of porosity fluctuations.

cond-mat↗