Special Functions and the Limit Properties of Probability Distributions. I

Author(s):  
V. M. Kalinin
2010 ◽  
Vol 20 (06) ◽  
pp. 1005-1020 ◽  
Author(s):  
ESTER GABETTA ◽  
EUGENIO REGAZZINI

We analyze a class of probability distributions for family sizes in a duplication, loss and change (DLC) model of genome evolution, recently introduced by Tiuryn, Wójtowicz and Rudnicki. After providing expressions for the generating functions of the density p and of the right-tail Q of the above distributions, we obtain closed forms for p and Q in terms of Gauss hypergeometric functions. Then, by resorting to the literature about special functions and their approximations, we provide an asymptotic expression for Q, which depends on parameters connected with the strengths of duplication and change. This shows that the DLC model yields a rich statistical model for the size distribution, whose elements are characterized by a composition of a power component with a negative exponential one. We also study the limiting distributions, as the parameters are made arbitrarily close to points of the boundary of their natural domain. In addition to the geometric distribution and to the unit mass at 1, the limiting class contains the distributions with the "longest" tails in the DLC model. A characterization of these probability laws is given.


2020 ◽  
Vol 8 (6) ◽  
pp. 1902-1908

In this paper we will introduce some probability distributions with help of some special functions like Gamma, kGamma functions, Beta, k-Beta functions, Bessel, modified Bessel functions and Laguerre polynomials and in mathematical analysis used Laplace transform. We will also obtain their cumulative density function, expected value, variance, Moment generating function and Characteristic function. Some characteristics and real life applications will be computed in tabulated for these distributions


2018 ◽  
Vol 34 (1) ◽  
pp. 09-15
Author(s):  
ADINA BARAR ◽  
◽  
GABRIELA RALUCA MOCANU ◽  
IOAN RASA ◽  
◽  
...  

We consider a family of probability distributions depending on a real parameter and including the binomial, Poisson and negative binomial distributions. The corresponding index of coincidence satisfies a Heun differential equation and is a logarithmically convex function. Combining these facts we get bounds for the index of coincidence, and consequently for Renyi and Tsallis entropies of order 2.


1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.


2020 ◽  
Vol 3 (1) ◽  
pp. 10501-1-10501-9
Author(s):  
Christopher W. Tyler

Abstract For the visual world in which we operate, the core issue is to conceptualize how its three-dimensional structure is encoded through the neural computation of multiple depth cues and their integration to a unitary depth structure. One approach to this issue is the full Bayesian model of scene understanding, but this is shown to require selection from the implausibly large number of possible scenes. An alternative approach is to propagate the implied depth structure solution for the scene through the “belief propagation” algorithm on general probability distributions. However, a more efficient model of local slant propagation is developed as an alternative.The overall depth percept must be derived from the combination of all available depth cues, but a simple linear summation rule across, say, a dozen different depth cues, would massively overestimate the perceived depth in the scene in cases where each cue alone provides a close-to-veridical depth estimate. On the other hand, a Bayesian averaging or “modified weak fusion” model for depth cue combination does not provide for the observed enhancement of perceived depth from weak depth cues. Thus, the current models do not account for the empirical properties of perceived depth from multiple depth cues.The present analysis shows that these problems can be addressed by an asymptotic, or hyperbolic Minkowski, approach to cue combination. With appropriate parameters, this first-order rule gives strong summation for a few depth cues, but the effect of an increasing number of cues beyond that remains too weak to account for the available degree of perceived depth magnitude. Finally, an accelerated asymptotic rule is proposed to match the empirical strength of perceived depth as measured, with appropriate behavior for any number of depth cues.


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