No 1 (2019)
EXACT SOLUTION OF SOME LINEAR VOLTERRA INTEGRO-DIFFERENTIAL EQUATIONS
Abstract
An exact real solution of linear Volterra - Fredholm and Volterra loaded integro-differential equation Bx = f is presented.
Applied Mathematics and Control Sciences. 2019;(1):7-21
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ON STABILITY WITH DERIVATIVE OF A CLASS OF DIFFERENTIAL EQUATIONS OF NEUTRAL TYPE
Abstract
We consider an important class of differential-difference equations of neutral type, for which we study the asymptotic properties of a solution. We present necessary and sufficient conditions of exponential stability. The conditions have a geometric form of a region in the parameter space. The behavior of a solution at the boundaries of the region is analyzed separately. The loss of stability on the boundary can occur in various ways, namely through the appearance of stationary solutions, and through the appearance of periodic modes. Along with the asymptotic properties of a solution, we study analogous properties of its derivative.
Applied Mathematics and Control Sciences. 2019;(1):22-50
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NUMERICAL CALCULATION OF THE CHANGE OF GEOMETRY OF THE WHEEL OF THE SPIRAL-CONICAL REDUCER AT HEAT TREATMENT
Abstract
In work simulation of heat treatment of krivozuby conic transfer of an intermediate reducer of the helicopter in the Deform-3D and ANSYS programs is carried out, methods of the prevention of change of the geometrical sizes of a detail in the course of heat treatment are offered. It in turn will allow to improve maintainability indicators. In the conditions of the raised loading, responsibility, military operations of Mi-28H has to "survive" and normally function in various conditions of environment, at influence of the strong destroying factors, such as an overload, high speed, shock loadings, vibration, etc. In this regard reducers too should work in the conditions of high loadings. Purpose of the main reducer is a distribution of power between helicopter mechanisms which is transferred by engines. Also, the main reducer is necessary to provide the draft force sufficient for the flight modes. Thus consumes the main share of power bearing the screw which is installed on a shaft of the main reducer. Management of a step and rotation of the steering screw is carried out by a tail reducer at which the transfer relation as well as an intermediate reducer small, and transfer is carried out at an angle 90°. Taking into account all parameters the major and topical questions in branch of helicopter engineering which decision will allow to increase reliability and durability, to reduce metallosses and to increase profitability of production at production of details are considered.
Applied Mathematics and Control Sciences. 2019;(1):53-62
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MODELING OF THE PRIVILEGED REFERENCE SYSTEMS
Abstract
It is shown that for uniform and rectilinear motion of two, three or several free inert bodies in one-dimensional or three-dimensional space, arbitrary inertial frames of reference, including those associated with each of the moving inert bodies, are not substantially equivalent in the part of the total kinetic energy. In this case, none of these frames of reference is not unique or distinguished. If it is necessary to select a unique or selected inertial reference frame, one can start from the condition of a minimum of the total kinetic energy of the moving inert bodies in this system. In this case, a unique or distinguished inertial reference system is a relict reference frame connected with the center of masses of the moving inert bodies and with the epicenter of their initial hypothetical interaction. Relict systems of reference are calculated. The bodies do not necessarily interact with them in the first place. The use of relict reference systems allows you to maintain a balance between kinetic energy and the work done. The number of inert bodies in calculating the relict frame of reference can be arbitrarily large.
Applied Mathematics and Control Sciences. 2019;(1):63-69
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THE SYSTEM OF REGISTRATION OF PARAMETERS OF HIGH-VOLTAGE ACCELERATORS WHEN THE MAXIMUM OPERATING VOLTAGE
Abstract
The purpose of this work is the development of software and hardware, their further implementation into the system as a separate component of the whole system, and ultimately - the conduct of physical experiments on the accelerator on the cascade generator KG-2.5 with the registration of the main parameters in real time. Development of software in the language Turbo Pascal 7.1 and the introduction of IBM PC into the system makes it possible to transfer the system to a partial automatic mode of the accelerator, and then further improvement of the system will completely transfer it to full automatic mode.
Applied Mathematics and Control Sciences. 2019;(1):73-86
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THE APPLICATION OF SYSTEMIC-COGNITIVE ANALYSIS IN THE INDUSTRY FORECASTING THE FINANCIAL SITUATION OF ENTERPRISES (FOR EXAMPLE CONSTRUCTION INDUSTRY)
Abstract
The article is devoted to the development of an industry model for assessing the financial position of enterprises using the method of automated system-cognitive analysis. It is proved that the existing models have not enough high prognostic ability regarding the financial position of enterprises in a particular industry. The models do not take into account the peculiarities of the financial reporting structure, which directly depends on the specifics of the field of activity. In the sample of the study included domestic construction companies. On the basis of their balance sheets identified the main financial signs of bankruptcy and economic prosperity. In addition, a reliable model for assessing the financial situation has been developed.
Applied Mathematics and Control Sciences. 2019;(1):87-99
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CREATING NEURAL NETWORK FOR IDENTIFICATION OF POTENTIAL BANK CUSTOMERS
Abstract
The article is devoted to the application of the Data Mining «Neural Network» algorithm for analyzing the available data of potential bank customers. The article discusses the possibilities and features of the creation and use of neural networks when conducting a comprehensive data analysis and building a system for further forecasting. The authors set the task of identifying the main characteristics of potential customers that affect a person’s desire to continue interacting with the bank after offering services to them. Based on the task, the neural network is created on the basis of the created multidimensional data structure to be able to predict the prospects of interaction with each client. The constructed neural network allows identifying potential customers based on new customer data to develop further marketing campaigns and optimize banking strategies aimed at improving long-term customer interaction.
Applied Mathematics and Control Sciences. 2019;(1):103-112
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CORRELATION and REGRESSIONAL ANALYSIS OF THE DEPENDENCE of ENTERPRISE receipts from THE FOREIGN ECONOMIC ACTIVITY FACTORS
Abstract
A correlation-regression analysis of the company's revenue dependence on the foreign economic activity factors was performed using the example of the Center for Appraisal and Analytical Technologies “Analytics.” The employees number ( x 1), rate $ ( x 2), rate € ( x 3), number of new open representative offices and branches for the period ( x 4) and service names in the company's nomenclature at the end of the period ( x 5) and number of suppliers at the end of the period ( x 6) revenue from the sale of medical equipment for the period ( x 7) and revenues from equipment maintenance and repair activities for the period ( x 8) and revenues from other activities for the period ( x 9), customs duties on equipment imports for the period ( x 10) and imports for the period ( x 11) and number of protectionism measures applied to the Russian Federation for the period ( х 12) and the number of measures of liberalization of foreign economic activity applied to the Russian Federation for the period ( x 13) was chosen as an external factor. The number of explanatory variables was reduced from 12 to 7 after the logical relationship between the factors analysis. Correlation analysis showed that many variables are intercorrelated. So, 8 regression models were constructed to avoid the negative effect of multicollinearity. These models do not contain strongly related factors. Statistical measures such as confidence intervals, the coefficient of determination, the Student’s index and the Fisher coefficient are given to assess the quality of the constructed models. It is shown that the constructed regression models are statistically significant. It’ll become possible to predict the results of the activity of the Center for Information Technologies "Analytics" in future periods if we used the regression models found. Also we could to minimize the risks due to the determination of the company's sources of income which determines the practical significance of the work.
Applied Mathematics and Control Sciences. 2019;(1):113-123
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