The random binary growth model

We describe a family of models of random partial orders, called classical sequential growth models, and study a specific case, which is the simplest interesting model, called a random binary growth model. This model produces a random poset, called a random binary order, B₂, on the vertex set ? by considering each vertex n ≥ 2 in turn and placing it above 2 vertices chosen uniformly at random from the set {0,…,n ? 1} (with additional relations added to ensure transitivity). We show that B₂ has infinite dimension, almost surely. Using the differential equation method of Wormald, we can closely approximate the size of the up‐set of an arbitrary vertex. We give an upper bound on the largest vertex incomparable with vertex n, which is polynomial in n, and, using this bound, we provide an example of a poset P, such that there is a positive probability that B₂ does not contain P. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005     

Fitting the extended poisson process model to grouped binary data

Summary  Extended Poisson process modelling allows the construction of a broad class of distributions, including distributions over-dispersed or under-dispersed relative to the binomial distribution, with the binomial distribution being a special case. In this paper an iteratively re-weighted least squares algorithm for fitting such generalised binomial distributions is presented, and is illustrated with an example.     

Practical analyticity of scattering amplitudes

Institute of Nuclear Research, USSR Academy of Sciences; All-Union Scientific-Research Institute of Physicotechnical and Radio Engineering. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 79, No. 3, pp. 416–422, June, 1989.     

Stochastic modeling of the growth process

In this paper we estimate the upper boundary of the number of trees in the selection stand determined for harvesting in a future. At the same time we showed that the present resource of the number of trees in selection stand is sustained. This is achieved by stochastic modeling of the number of trees and the number of felled trees and by solving the partial differential equation. The same problem is solved in the papers, Mitrović (Stochastic modeling of the number of trees and the number of felled trees in selection stands, YUJOR, vol 14(1), pp 57–64, 2004; Stochastic modeling of the number of felled trees in selection stands, Computational and Applied Mathematics, vol 24(2), pp 285–292, 2005). In this paper the modified mathematical model is represented.      

Remarks on the nonproportionality of wave and entropic amplitudes

The propagation of an acceleration wave through a Maxwellian nonconductor is modelled, and a relationship between entropic amplitude and the amplitude of the wave is derived; for the general model introduced, it is found that these two amplitudes are not proportional, as they would be in a simple material with fading memory, and that proportionality holds if and only if a simple explicit relationship connects two of the constitutive coefficients at the wave front.     

Transient amplification of maximum vibration amplitudes

Many low damped structures as turbine blades or drill strings are exposed to high dynamical loads causing high vibration amplitudes. These applications comprise sub-critical eigenfrequencies. Hereby, the lower eigenfrequencies have to be passed before reaching the operating point. Most investigations of vibration amplitudes caused by a resonance passage deal with the computation of single degree of freedom systems. Thereby, it has been shown that the stationary vibration response provides the highest possible amplitude. Further it can be stated that the maximum vibration response of the resonance passage decreases with an increasing sweep velocity [3]. Isolated modes of linear systems can be represented by single degree of freedom systems. Subsequently a mode shape can be described by the multiplication of the amplification function of the mode and the belonging eigenvector. There are only some recent works that deal with resonance passages of vicinal modes, e. g. [1]. In this paper the resonance passage of a three dimensional system with nearby modes is studied. To calculate the transient vibration response an analytical approach is used. It is shown that the maximum amplitude of the stationary vibration response is not the upper limit for the maximum amplitude of the resonance passage. Thus, the maximum amplitude may rise while the sweep velocity increases. Hence, regarding a multi degree of freedom system the maximum amplitude of the resonance passage can exceed the maximum amplitude of the stationary vibration response. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Binary geometric process model for the modeling of longitudinal binary data with trend

We propose the Binary Geometric Process (BGP) model for longitudinal binary data with trends. The Geometric Process (GP) model contains two components to capture the dynamics on a trend: the mean of an underlying renewal process and the ratio which measures the direction and strength of the trend. The GP model is extended to binary data using a latent GP. The statistical inference for the BGP models is conducted using the least-square, maximum likelihood (ML) and Bayesian methods. The model is demonstrated through simulation studies and real data analyzes. Results reveal that all estimators perform satisfactorily and that the ML estimator performs the best. Moreover the BGP model is better than the ordinary logistic regression model.     

Analytic properties of multiparticle production amplitudes

Theoretical and Mathematical Physics -     

Operations on binary relations

The effects of five basic operations (asymmetrization, complementation, dualization, symmetrization, transitive closure) on binary relations are examined. Identifies between compound operations are developed (e.g. the symmetric part of the transitive closure of the complement of the transitive closure equals the transitive closure of the symmetric complement of the transitive closure), ordering aspects of compound operations are noted, and it is shown that in addition to the empty and universal relations at most 110 different relations can be generated from a given binary relation by sequential applications of the five basic operations. Moreover, 110 is the least upper bound, and none of these 110 requires more than seven applications of the basic operations for its expression. One of the potentially irreducible compound operations of length seven is cstcatc, the complement of the symmetric part of the transitive closure of the complement of the asymmetric part of the transitive closure of the complement.     

On vertex parts of p-adic Feynman amplitudes

We reduce the calculation of the vertex parts of p-adic Feynman amplitudes to a recursive procedure for evaluating singular parts of certain integrals. We propose an algorithm for calculating these integrals in the general form. As an example, we consider vertex parts of amplitudes in the ? ⁴ theory.     

A cellular automaton technique for modelling of a binary dendritic growth with convection

A two-dimensional model for the simulation of a binary dendritic growth with convection has been developed in order to investigate the effects of convection on dendritic morphologies. The model is based on a cellular automaton (CA) technique for the calculation of the evolution of solid/liquid (s/l) interface. The dynamics of the interface controlled by temperature, solute diffusion and Gibbs–Thomson effects, is coupled with the continuum model for energy, solute and momentum transfer with liquid convection. The solid fraction is calculated by a governing equation, instead of some approximate methods such as lever rule method [A. Jacot, M. Rappaz, Acta Mater. 50 (2002) 1909–1926.] or interface velocity method [L. Nastac, Acta Mater. 47 (1999) 4253; L. Beltran-Sanchez, D.M. Stefanescu, Mat. and Mat. Trans. A 26 (2003) 367.]. For the dendritic growth without convection, mesh independency of simulation results is achieved. The simulated steady-state tip velocity are compared with the predicted values of LGK theory [Lipton, M.E. Glicksmanm, W. Kurz, Metall. Trans. 18(A) (1987) 341.] as a function of melt undercooling, which shows good agreement. The growth of dendrite arms in a forced convection has been investigated. It was found that the dendritic growth in the upstream direction was amplified, due to larger solute gradient in the liquid ahead of the s/l interface caused by melt convection. In the isothermal environment, the calculated results under very fine mesh are in good agreement with the Oseen–Ivanstov solution for the concentration-driven growth in a forced flow.