scholarly journals Analysis of the development of the livestock sector in agricultural enterprises of Ukraine for 1995-2017

Author(s):  
A. Nepochatenko ◽  
V. Nepochatenko

The theoretical analysis of possible single-factor regressions, which correspond to the decrease in the number of livestock of agricultural animals during the crisis period and increase their number at the exit from the crisis state, is made in the work. It is shown that during the crisis period, the dynamics of the reduction of the livestock correspond to the modified exponential regression. It is proposed to find two parameters of these regressions using the least squares method, the third one to be determined by the numerical method with a minimum of MAPE. With the growth of livestock caused by an increase in investments, this evolution corresponds to a modified logistic regression. The two logistic regression parameters find using the least squares method, the third and fourth parameters were determined by numerical method with a minimum of MAPE, as functions of two variables. The obtained theoretical conclusions are in good agreement with the statistical data that correspond to the dynamics of the number of cows, pigs, sheep, goats and poultry in Ukraine for the period 1995-2017. It was shown that changes in the number of cows during the whole period under investigation correspond to the modified exponential regression. The stock of pigs from 1995 to 2001 in agricultural enterprises of Ukraine also decreased under the exponential law. Since 2002 there has been a gradual increase in the number of pigs - including until 2013. In this period, the dynamics corresponded to the logistic regression of Pearl-Reed. Beginning in 2014, due to the loss of part of Ukraine's controlled areas and the complicated epizootic situation (African swine fever), the gradual decrease in the number of pigs began. The modified exponential regression also corresponded to the change in livestock of sheep and goats in agricultural enterprises of Ukraine in 1995-2005. From 2006 to 2010 there was a slight increase in livestock, then its gradual decrease, and from 2014 the total number of sheep and goats was again in line with the modified exponential regression. The dynamics of the number of poultry in agricultural enterprises in Ukraine resembles the process of changing the number of pigs. At first, it decreased, then grew. Between 1995 and 2000, the number of poultry decreased by exponential dependence. Starting from 2001 to 2013, the number of poultry increased annually, which is explained by the significant increase in the volume of state support for the poultry industry. During this period, the change in the size of the poultry fitted well with the modified logistic regression of Pearl-Reed. In 2014-2016, the number of poultry decreased annually, primarily due to changes in the geographical structure of exports. In order to begin the outbreak of the livestock sector from the crisis, it is necessary to increase the volume of domestic and foreign investment in fixed capital, increase the purchasing power of the population, the level of purchasing prices for milk and meat, improve the credit policy, and increase the amount of state aid to agricultural producers. In addition, it is necessary to create appropriate conditions for the expansion of product markets, first of all, by ensuring the process of modernization of production on an innovative basis, which will contribute to improving the quality characteristics of manufactured products in accordance with modern requirements of European and international standards. The said will allow to significantly increase the volume of agricultural production and will contribute to increasing the competitiveness of national agrarian commodity producers both in the domestic and world markets. Key words: animal husbandry in agricultural enterprises, logistic and exponential regression, forecasting.

BIOMATH ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 1604231
Author(s):  
A.N. Pete ◽  
Peter Mathye ◽  
Igor Fedotov ◽  
Michael Shatalov

An inverse numerical method that estimate parameters of dynamic mathematical models given some information about unknown trajectories at some time is applied to examples taken from Biology and Ecology. The method consisting of determining an over-determined system of algebraic equations using experimental data. The solution of the over-determined system is then obtained using, for example the least-squares method. To illustrate the effectiveness of the method an analysis of examples and corresponding numerical example are presented.


1980 ◽  
Vol 59 (9) ◽  
pp. 8
Author(s):  
D.E. Turnbull

2020 ◽  
Vol 1 (3) ◽  
Author(s):  
Maysam Abedi

The presented work examines application of an Augmented Iteratively Re-weighted and Refined Least Squares method (AIRRLS) to construct a 3D magnetic susceptibility property from potential field magnetic anomalies. This algorithm replaces an lp minimization problem by a sequence of weighted linear systems in which the retrieved magnetic susceptibility model is successively converged to an optimum solution, while the regularization parameter is the stopping iteration numbers. To avoid the natural tendency of causative magnetic sources to concentrate at shallow depth, a prior depth weighting function is incorporated in the original formulation of the objective function. The speed of lp minimization problem is increased by inserting a pre-conditioner conjugate gradient method (PCCG) to solve the central system of equation in cases of large scale magnetic field data. It is assumed that there is no remanent magnetization since this study focuses on inversion of a geological structure with low magnetic susceptibility property. The method is applied on a multi-source noise-corrupted synthetic magnetic field data to demonstrate its suitability for 3D inversion, and then is applied to a real data pertaining to a geologically plausible porphyry copper unit.  The real case study located in  Semnan province of  Iran  consists  of  an arc-shaped  porphyry  andesite  covered  by  sedimentary  units  which  may  have  potential  of  mineral  occurrences, especially  porphyry copper. It is demonstrated that such structure extends down at depth, and consequently exploratory drilling is highly recommended for acquiring more pieces of information about its potential for ore-bearing mineralization.


1984 ◽  
Vol 49 (4) ◽  
pp. 805-820
Author(s):  
Ján Klas

The accuracy of the least squares method in the isotope dilution analysis is studied using two models, viz a model of a two-parameter straight line and a model of a one-parameter straight line.The equations for the direct and the inverse isotope dilution methods are transformed into linear coordinates, and the intercept and slope of the two-parameter straight line and the slope of the one-parameter straight line are evaluated and treated.


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