In 1995 Penna introduced a simple model of biological aging. A modified Penna model has been demonstrated to exhibit behavior of real-life systems including catastrophic senescence in salmon and a mortality plateau at advanced ages. We present a general steady-state, analytic solution to the Penna model which is able to deal with arbitrary birth and survivability functions. This solution is emp...

A new geometrical approach in solving the shape from shading problem of Lambertian model is discussed. It is shown that this problem is bound by two local constraints through the global and local geometrical analysis and through the direct geometrical interpretation of the problem. The analytical solutions, which are C continuous and which have two degrees of freedom due to the non-linear prope...

We show that scaling quantum graphs with arbitrary topology are explicitly analytically solvable. This is surprising since quantum graphs are excellent models of quantum chaos and quantum chaotic systems are not usually explicitly analytically solvable.

Analysis of the nonlinear Schrödinger vortex reconnection is given in terms of coordinate-time power series. The lowest order terms in these series correspond to a solution of the linear Schrödinger equation and provide several interesting properties of the reconnection process, in particular the nonsingular character of reconnections, the anti-parallel configuration of vortex filaments and a s...

In this paper we present a framework which provides an analytical (i.e., infinitely differentiable) transformation between spatial coordinates and orbital elements for the solution of the gravitational two-body problem. The formalism omits all singular variables which otherwise would yield discontinuities. This method is based on two simple real functions for which the derivative rules are only...

Studying the Bethe–Salpeter formalism for interactions instantaneous in the rest frame of the bound states described, we show that, for bound-state constituents of arbitrary masses, the mass of the ground state of a given spin may be calculated almost entirely analytically with high accuracy, without the (numerical) diagonalization of the matrix representation obtained by expansion of the solut...

We present the exact solution to the non linear Monge differential equation λ(x, t)λx(x, t) = λt(x, t). It is widely accepted that the Monge equation is equivalent to the ODE .. X= 0 of free motion for particular conditions. Furthermore, the Monge Type equations are connected withX = F ( . X, X; t), which can be integrated with quadratures [1]. Other asymptotic solutions are discussed, see e.g....

The Bethe–Salpeter equation for bound states of a fermion–antifermion pair in the instantaneous approximation for the involved interaction kernel is converted into an equivalent matrix eigenvalue problem with explicitly (algebraically) given matrices. PACS numbers : 11.10.St, 03.65.Ge ∗ E-mail address : [email protected] ‡ E-mail address : [email protected] † E-mail address : franz.schoebe...

We study formation and interaction of one-dimensional screening solitons in a photorefractive medium with sublinear dependence of the photoconductivity on light intensity. We find an exact analytical solution to the corresponding nonlinear Schrodinger equation. We show that these solitons are stable in propagation and their interaction is generic for solitons of saturable nonlinearity. In parti...

1. I n t r o d u c t i o n The problem of determining rigid body motion and surface structure from image data has been the topic of many research papers in the area of machine vision 11-22]. Many approaches based on tracking feature points [5,11,19,20] or contours 191, using optical flow 11,3,4,10,12,16,17,21,22], texture 121, or image intensity gradients j14,15] have been proposed in the liter...