№ 104(10), December, 2014
Public date: 30.12.2014
Archive of journal: Articles count 150, 359 kb
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01.00.00 Physical-mathematical sciences
01.00.00 Physical-mathematical sciences
Description
We have proposed the method for testing of independence of two alternative variables on the basis of statistics of non-numeric data. The method is aimed at application in problems of statistical quality control. Testing of independence is based on set of small samples, i.e., in the Kolmogorov’s asymptotics, when the number of unknown parameters of the distribution increases in proportion to the data size
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ABOUT THE METHODOLOGY OF STATISTICAL METHODS
01.00.00 Physical-mathematical sciences
Description
The purpose of the article - to justify the need to develop the methodology of statistical methods as an independent scientific direction. The models of mathematician and applied specialist are presented. We have obtained the conclusions on teaching and research and discussed five major unsolved problems of statistical methods: the effect of deviations from the traditional prerequisites; use asymptotic results for finite sample sizes; selecting one of the many specific tests for the hypothesis; organization of theoretical work in the field of statistical methods; conduct applied research and teaching of statistical methods
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TWO-SAMPLE WILCOXON TEST - ANALYSIS OF TWO MYTHS
01.00.00 Physical-mathematical sciences
Description
It was established that the two-sample Wilcoxon test (Mann-Whitney test) was designed to test the hypothesis H0: P(X
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01.00.00 Physical-mathematical sciences
Description
In this article we have proposed a method using the apparatus of fuzzy sets theory in conjunction with the five-factor model of Altman to assess the creditworthiness of the investigated companies. The Altman model was improved in two ways: by using RMS integral approximation for the exact calculation of the quantitative credit assessment (probability of bankruptcy) and the application of the apparatus of fuzzy sets for ordered sets by the degree of confidence resulting probability
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01.00.00 Physical-mathematical sciences
Description
This article continues the works [1,2], devoted to the theoretical study of the basic laws of electroconvection caused by natural or artificial inhomogeneous conductivity of ion-exchange membranes in a smooth rectangular channel electrodialysis desalination unit. For this purpose, a mathematical model was created for a binary electrolyte electroconvection at overlimiting current modes in the form of a boundary value problem for a coupled system of the Nernst-Planck-Poisson and Navier-Stokes equations. We have studied the influence of heterogeneity on the ion-exchange membranes and ion transport electroconvection salt, calculated currentvoltage characteristic. The possibility of intensification of mass transfer due to the surface modification of ion exchange membranes was also shown
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FORECASTING THE WATER LEVEL IN A RIVER WITH THE ABRUPT FALLING WATER BASED ON KALMAN-BUSY FILTRATION
01.00.00 Physical-mathematical sciences
Description
The technique of short-term forecasting of the water level in a vein of a mountain type river, based on a method of Kalman-Busy filtration in the make assumption of natural simplifications, characterized for natural objects is offered
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01.00.00 Physical-mathematical sciences
Description
A simple climate–economic model based on the AK model of economic growth with the endogenous depreciation rate linear in temperature and on the exogenous climate scenario with temperature linear in time is considered. The analytical solution of the model is obtained. The uncertainty of temperature projections is introduced in the model, and the moments of model state variable are calculated analytically. Numerical examples are provided
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01.00.00 Physical-mathematical sciences
Description
The article describes a numerical example of creating intellectual application designed to predict solar flares of different classes on the basis of the history of their development in the environment of "Eidos" system. As the source data, we used the database of UCI repository
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01.00.00 Physical-mathematical sciences
Description
The method of ordinary least squares (OLS) is widely known and deservedly popular. However, some attempts to improve this method. The result of one of such attempts is the weighted least squares (WMNC), the essence of which is to give the observation a weight which is inversely proportional to the errors of their approximation. Thereby, in fact, monitoring is ignored the more the difficult to approximate it. The result of this approach, formally, is the approximation error decreasing, but in fact, this occurs by partial refusal to consider the "problem" of observations, making a big mistake. If the idea underlying WMNC to bring to the extreme (and absurd), then in the limit, this approach will lead to the fact that from the entire set of observations there will be only those that lie almost exactly on the trend obtained by the method of least squares, and the rest will simply be ignored. However, according to the author, it's not a problem, and the failure of its decision, though it might look like a solution. In the work we have proposed a solution, based on the theory of information: to consider the weight of observations, the number of the argument of the value function. This approach was validated in the framework of a new innovative method of artificial intelligence: methods for automated system-cognitive analysis (ASA-analysis) and implemented 30 years ago in its software toolkit, which is "Eidos" intelligent system in the form of so-called "cognitive functions". This article presents an algorithm and software implementation of this approach, illustrated in detailed numerical example. In the future it is planned to give a detailed mathematical basis of the method of weighted least squares, which is modified by the application of information theory to calculate the weights of the observations, and investigate its properties
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01.00.00 Physical-mathematical sciences
Description
Wave solutions of Einstein's equations in the sixdimensional space-time with metric signature (+, +, +, -, -, -) have been found. It is shown that solutions of this type can be used to model the structure of the electric charge
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