Pulse interaction in nonlinear vacuum electrodynamics

The energy-momentum conservation law is used to investigate the interaction of pulses in the framework of nonlinear electrodynamics with Lorentz-invariant constitutive relations. It is shown that for the pulses of the arbitrary shape the interaction results in phase shift only.Comment: LaTeX, 5 pages, 2 EPS figure

Method optimization of models parameters for the nonstationary traffic in telecommunication network

Результати параметрів моделі оптимізації для нестаціонарного руху в телекомунікаційних та комп'ютерних мереж наведено. Для оптимального моделювання динаміки руху метрик Евкліда і просторів Гілберта використовуються. Техніка та алгоритм оптимізації моделей розроблені. Теоретичні положення ілюструються чисельними прикладами і схемами з використанням ofMathCADРезультаты параметров модели оптимизации для нестационарного движения в телекоммуникационных и компьютерных сетей приведены . Для оптимального моделирования динамики движения метрик Евклида и пространств Гилберта используются . Техника и алгоритм оптимизации моделей разработаны . Теоретические положения иллюстрируются численными примерами и схемами с использованием ofMathCADResults of models parameters optimization for the nonstationary traffic in telecommunication and computer networks are given. For optimum modeling of the traffic dynamics metrics of Euclid’s and Gilbert’s spaces are used. The technique and algorithm of models optimization are developed. Theoretical positions are illustrated by numerical examples and diagrams with use ofMathCA

First crossing time, overshoot and Appell-Hessenberg type functions

We consider a general insurance risk model with extended flexibility under which claims arrive according to a point process with independent increments, their amounts may have any joint distribution and the premium income is accumulated following any non-decreasing, possibly discontinuous, real valued function. Point processes with independent increments are in general non-stationary, allowing for an arbitrary (possibly discontinuous) claim arrival cumulative intensity function which is appealing for insurance applications. Under these general assumptions, we derive a closed form expression for the joint distribution of the time to ruin and the deficit at ruin, which is remarkable, since as we show, it involves a new interesting class of what we call Appell-Hessenberg type functions. The latter are shown to coincide with the classical Appell polynomials in the Poisson case and to yield a new class of the so called Appell-Hessenberg factorial polynomials in the case of negative binomial claim arrivals. Corollaries of our main result generalize previous ruin formulas e.g., those obtained for the case of stationary Poisson claim arrivals

On costa variation in leaves of fossil permian protoshagnalean mosses

Leaves of extinct mosses of the order Protosphagnales are studied with the special attention to their different developmental stages. A previously unknown morphotypes without costa and with very short costa are revealed in this group. It is characteristic for young small leaves of Kosjunia and Intia , but apparently does not occur in other genera of this fossil order. The present collection allows restore a heteroblastic series in these leaves and associated with it differentiation of laminal areolationyesBelgorod State National Research Universit

Radiation-Induced "Zero-Resistance State" and the Photon Assisted Transport

We demonstrate that the radiation induced "zero-resistance state" observed in a two-dimensional electron gas is a result of the non-trivial structure of the density of states of the systems and the photon assisted transport. A toy model of a structureless quantum tunneling junction where the system has oscillatory density of states catches most of the important features of the experiments. We present a generalized Kubo-Greenwood conductivity formula for the photon assisted transport in a general system, and show essentially the same nature of the transport anomaly in a uniform system.Comment: 4 pages, 3 figures. Please send comment to [email protected]. This version added a paragraph to discuss the implication of negative conductanc

Finite Time Non-Ruin Probability Formulae for Erlang Claim Interarrivals and Continuous Interdependent Claim Severities

A closed form expression, in terms of some functions which we call exponential Appell polynomials, for the probability of non-ruin of an insurance company, in a finite-time interval is derived, assuming independent, non-identically Erlang distributed claim inter-arrival times, τi ∼ Erlang (gi, λi) , i = 1, 2, . . ., any continuous joint distribution of the claim amounts and any non-negative, non-decreasing real function, representing its premium income. In the special case when τi ∼ Erlang (gi, λ) , i = 1, 2, . . . it is shown that our main result yields a formula for the probability of non-ruin expressed in terms of the classical Appell polynomials. We give another special case of our non-ruin probability formula for τi ∼ Erlang (1, λi) , i = 1, 2, . . ., i.e., when the inter-arrival times are non-identically exponentially distributed and also show that it coincides with the formula for Poisson claim arrivals, given in [18], when τi ∼ Erlang(1, λ), i = 1, 2, . . .. The main result is extended further to a risk model in which inter-arrival times are dependent random variables, obtained by randomizing the Erlang shape or/and rate parameters. We give also some useful auxiliary results which characterize and express explicitly (and recurrently) the exponential Appell polynomials which appear in our finite time non-ruin probability formulae