نتایج جستجو برای: logistic growth

تعداد نتایج: 917935  

A. Naazie B.B. Kayang I.M. Barchia P.F. Arthur, R. Osei-Amponsah

The logistic, Gompertz, Richards and asymmetric logistic growth curve models were fitted to body weight data of local Ghanaian chickens and French SASSO T44 chickens. All four growth models provided good fit for each sex by genotype growth data with R2 values ranging from 86.7% to 96.7%. The rate constant parameter, k, ranged between 0.137 and 0.271 and were significantly different from zero fo...

قوی حسین زاده, نوید, میرحسینی, سید ضیاالدین, هادی نژاد, فاطمه,

The objective of this study was to select the best model among five non-linear growth functions, i.e., Brody, Gompertz, Logistic, Von Bertalanffy and Negative exponential for describing the growth curve in Markhoz goat. The data included 5557 body weight records of goats from birth to yearling which were collected during 2006 to 2013 at Sanandaj Research Station. Growth curve parameters (A, B, ...

The population growth, is increase in the number of individuals in population and it depends on some random environment effects. There are several different mathematical models for population growth. These models are suitable tool to predict future population growth. One of these models is logistic model. In this paper, by using Feynman-Kac formula, the Adomian decomposition method is applied to ...

2005
A. LAMBERT

In order to model random density-dependence in population dynamics, we construct the random analogue of the well-known logistic process in the branching process’ framework. This densitydependence corresponds to intraspecific competition pressure, which is ubiquitous in ecology, and translates mathematically into a quadratic death rate. The logistic branching process, or LB-process, can thus be ...

2003
URSZULA FORYŚ ANNA MARCINIAK-CZOCHRA

The aim of this paper is to present some approaches to tumour growth modelling using the logistic equation. As the first approach the well-known ordinary differential equation is used to model the EAT in mice. For the same kind of tumour, a logistic equation with time delay is also used. As the second approach, a logistic equation with diffusion is proposed. In this case a delay argument in the...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2003
Bao-Quan Ai Xian-Ju Wang Guo-Tao Liu Liang-Gang Liu

The logistic differential equation is used to analyze cancer cell population, in the presence of a correlated Gaussian white noise. We study the steady state properties of tumor cell growth and discuss the effects of the correlated noise. It is found that the degree of correlation of the noise can cause tumor cell extinction.

2003
FLOYD B. HANSON

A stochastic differential equation for a discontinuous Markov process is employed to model the magnitude of a population which grows logistically between disasters which are proportional to the current population size (density independent disasters). The expected persistence or extinction time satisfies a singular differential-difference equation. When the number of disasters, in the absence of...

Journal: :Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan 2003
Hiroshi Fujikawa Akemi Kai Satoshi Morozumi

A new logistic model for bacterial growth was developed in this study. The model is based on a logistic model, which is often applied for biological and ecological population kinetics. The new model is described by a differential equation and contains an additional term for suppression of the growth rate during the lag phase, compared with the original logistic equation. The new model successfu...

1998
Swapna S. Gokhale Kishor S. Trivedi

Finite failure NHPP models proposed in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault, and are inadequate to describe the failure process underlying certain failure data sets. In this paper, we propose the loglogistic reliability growth model, which can capture the increasing=decreasing nature of the failure occurrence rat...

Journal: :Mathematical biosciences 2006
Víctor Padrón María Cristina Trevisan

We consider a single-species model which is composed of several habitats connected by linear migration rates and having logistic growth. A spatially varying, temporally constant environment is introduced by the non-homogeneity of its carrying capacity. Under this condition any type of purely diffusive behavior, characterized in our model by symmetric migration rates, produces an unbalanced popu...

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