INVESTIGATION OF A TWO-FACTOR FULLY CONNECTED LINEAR REGRESSION MODEL
This paper is devoted to the study of a fully connected linear regression model, which is a synthesis of the pairing linear regression model and the Deming regression model. If multiple regression is based on the principle “independent variables influence dependent”, then the principle of fully connected regression is “all variables influence each other”. A fully connected regression is fairly simply estimated, devoid of multicollinearity effect, has a much more diverse interpretation than multiple regression, and is suitable for prediction. However, when building a fully connected regression, the ratio of error variances of independent variables remains unknown. In this paper, we find the ratio of error variances of independent variables that provides the best approximation qualities of the secondary fully connected regression model. The research results are presented in the form of a theorem. It follows from the theorem that the value of the coefficient of determination of the secondary model of a fully connected regression will be greatest either when it takes the form of a two-factor linear regression or the best one in the coefficient of determination of a single-factor linear regression. Thus, the selection of informative regressors in the regression model is carried out. It is established that the basis of such a selection is the complete consistency of the signs of the coefficients with independent variable signs of the corresponding correlation coefficients.
Keywords: :fully connected regression, multiple regression, Deming regression, EIV-model, coefficient of determination, multicollinearity, subset selection in regression
ADAPTIVE AUTOMATED SYSTEM AS A TRAINING DIFFERENTIATION MEANS IN THE INFORMATION TECHNOLOGY SPECIALISTS EDUCATION PROCESS
UDC 004.9, 37.04
N.V. Datsenko, S.A. Gorbatenko, V.V. Gorbatenko
One of the most effective ways to implement a differentiated approach in the information technology (IT) specialists training which consists in the adaptive automated learning system use is proposed in the article. The system will allow to store a large amount of educational information, to modify it if necessary, to adapt it to different categories of users in accordance with their level of initial training, to check the formation of competencies and analysis of mistakes made by students in the control testing process. The system dataware includes a relational database (DB), which contains theoretical information of the discipline, exercises and control tasks on all topics, adapted to different categories of students, as well as a table in which all erroneous answers of users are entered during the control testing for further analysis. The software contains the users automatic classification module which is based on the cluster analysis method and allows at the input control stage to form four groups of students depending on the level of residual knowledge obtained in the previous disciplines study, corresponding to the marks as “excellent”, “good”, “satisfactory” and “unsatisfactory”, in order to differentiate the educational material. The training program module is designed to solve the problems of new knowledge acquiring by students of different groups, using the theoretical knowledge obtained in the practical tasks implementation and checking the competence formation level. In the event that the level has not reached the baseline, the error analysis module allows to determine which discipline subjects have caused the greatest difficulties for the student to re-study.
Keywords: :training differentiation, IT disciplines, improving the training quality, adaptive automated system, automatic classification, cluster analysis
MATHEMATICAL SUPPORT THE PROCESS OF MANAGING DIAGRAM OF RELATIONAL DATABASES IN HORIZONTAL SCALING TASKS
D.D. Gromey, E.V. Lebedenko
The article proposes an approach to the development of mathematical support system for the relational database (database control system) schematic control process, allowing to take into account the statistics of competitive access to the data query flow in the memory used by the database control system engine by hierarchy. The articles notes shortcomings of existing approaches based on the conditional costs of the query plan and the issue of ignoring the costs related to cooperative access to the data contained in a shared computer memory. There is a set-theoretic presentation of the query flow processing, which also takes into consideration the shortcomings of the existing set-theoretic models. The proposed approach ensures the actual time costs calculations for the flow of concurrently executed queries. High-level query language operations are provided through a variety of typical access operations to the In-Memory Data. The article presents a classification of the memory access operations, which allows to calculate the degree of competition during the cooperative query execution. This study also introduces a formal presentation of competitive queries and the conditions for choosing the optimal data distribution method during the database operation in a given period of time. The proposed set-theoretic model allows us to calculate the memory segments, access to which leads to a competitive query. The results obtained in this paper can be used in the development of mathematical support systems and other software for the Autonomous database control systems that automate the management of the physical database scheme.
Keywords: :database management system, query optimization, parallel data processing, competitive queries.
OPENMP PARALLEL CALCULATIONS IN ALGORITHMS FOR SOLVING SHORTEST PATHS PROBLEM
O.Y. Lavlinskaya, V.V. Bernikov, O.N. Grigorova
The relevance of the study is due to the need to solve the problems of parallelization of calculations for the class of NP-complete problems, since computing power allows the use of parallel flows and reduce the computation time and energy consumption to obtain a complex computational result using software technologies of parallelization of calculations. In this regard, this article aims to publish the results of the study, based on the analysis of empirical data, proving the effectiveness of parallel calculations for the class of NP-complete problems. The article compares the work of a single-threaded application and multithreaded applications using OpenMP technology, on the example of the Floyd-Warshall Algorithm for finding the shortest path. During the experiment, data on the speed of serial and parallel algorithms were obtained. It is concluded that the parallel algorithm is more efficient than the serial one. With the growth of the computational power of the algorithm, the efficiency of parallel computing increases. The experiment was carried out for calculations at different power of a set of initial data, the data are presented in the form of tables and graphs. Evaluate the effectiveness of the use of standard parallelization and OpenMP. The materials of the article are of practical importance for master’s students studying the course “Computer systems”, can be used to solve applied optimization problems.
Keywords: :OpenMP, parallelization, search of ways, Floyd- Warshall algorithm.
ANALYSIS OF TOOLS AND AUTOMATION EQUIPMENT FOR ELECTRONIC COMMERCE
G.N. Vershinina, Y.I. Dreyzis, O.A. Burunin
E-commerce is a new kind of economic activity in modern Russia. Doing business via the Internet commerce can improve the competitiveness of the company. The article reveals the advantages and disadvantages of Internet commerce for companies, consumers and society. Types of the organization of the Websites for conducting electronic commerce of the enterprises are considered. The existing program complexes for creation of websites of the enterprises and conducting electronic commerce by them are analyzed.
The analysis of the existing approaches to the choice of the automation equipment of electronic commerce on the basis of the carried-out contrastive analysis of different tools, such, for example, as designers of the websites, CMS systems and generators of the websites was made. The technique of the choice of a CMS system for implementation of electronic commerce at the enterprise is considered and the basic concepts of efficiency of electronic commerce are analyzed. The technique of the choice of the automation equipment of electronic commerce, which can be used by the enterprises and the organizations for creation of websites by them (electronic portals) on the organization of electronic sales or provision of services via the Internet, is as a result developed
Keywords: :electronic commerce, tools electronic business, CMS-system, designers of sites.
METHOD OF THE SOLUTION OF SOME CLASSES OPTIMISING TASKS
The relevance of this work is caused by wide circulation in all spheres of activity of important practical tasks which can be solved by methods of linear programming. The main difficulty at application of a universal way of the solution of such tasks (a simplex – a method) is its computing complexity. For the solution of this problem special methods of the solution of private problems of linear programming, for example, are developed for positive or limited basic data. These special cases are proved by economic, social, technical, technological sense. In this article the method maximizing linear function at one linear restriction with positive coefficients is developed. This method is generalized on a case of maximizing linear function at several linear restrictions. The received theoretical results are proved by the proof of the corresponding theorems. For an illustration of the received results numerical examples are given. The algorithmic complexity of the developed method is estimated for solvable tasks by calculation of number of the used operations and comparison with their quantity when using a simplex – a method. The received results allow to solve applied optimizing problems in various areas, including in problems of planning of production, a balanced diet and a diet, management of educational process, etc.
Keywords: a problem of linear programming, function, restriction, coefficient, a simplex – a method, an optimal solution.
MODEL OF THE MANAGEMENT PROCESS IN REORGANIZATION OF STRUCTURES OF SOCIAL INSTITUTES OF THE PEOPLE’S REPUBLIC OF BANGLADESH
K.P. Ghosh, M.V. Shcherbakov
This work relates to the task of research and management of the reorganization of the structures of social institutions. The development of science-based management methods for reorganizing the structures of the social institutions of the People’s Republic of Bangladesh is an urgent scientific task. The problem arose as a result of the implementation of social programs aimed at increasing the autonomy of social institutions. To increase the autonomy of social institutions, the following management decisions are highlighted: leave the network structure in the current state; modify the existing network by changing the internal structure of social institutions; add new elements to the network (social institutions). In the process of reviewing the results of the work of an institution or institutions due to unprofitability, it is their or their liquidation and a decision is taken to change the organization’s profile of institutions in order to generate incomes to the network. In this paper, a model has been developed for managing the reorganization of structures of social institutions. As well, a model of the management process for changing the institutional profiles of institutions has been developed and the model algorithm described. The article gives an example of using the management process of reorganizing social society, examines in detail the process of managing changes in the institutional profiles of organizations and obtained a positive result of the proposed process.
Keywords: management process, reorganization, social institutions, the structure of social institutions, change in the profile of the organization.
EXPERT EVALUATION AND OPTIMIZATION MODELING OF CONTROL AND OVERSIGHT ACTIVITY ON ENSURING THE QUALITY OF DRUGS
I.V. Safonov, Y.E. Lvovich
Ensuring the quality of medicines is currently one of the most important provisions of the state health policy. To reduce the risk of receipt of substandard and counterfeit medicines to the population, it is necessary to optimize the functioning of the current system of control and supervision activities aimed at the optimal use of available resources under specified conditions and restrictions. The main form of control and supervisory activities are inspections of objects of circulation of medicines or objects of control. To ensure an optimal plan for the audit, an optimization model is proposed that minimizes the number of objects included in the inspection plan, taking into account the limitation on planned costs and the necessary frequency of inspection of producers at risk. At the same time, the maximum number of tested drugs should be provided during the inspection of each object. A model refers to the problems of the multialternative optimization. A two-step procedure is proposed to solve this problem. A typical problem of discrete programming is solved – the problem of minimal coverage. When searching for the number of dominant solutions to the problem, basic variational procedures are used to obtain several solutions. To select the best option, it is proposed to use expert evaluation procedures. The developed optimization model is aimed at wide application in the work of the regional Department of Roszdravnadzor of the Voronezh region.
Keywords: expert evaluation,optimization modeling, the problem of minimum coverage, control and supervisory activities, drugs.
AUTOMATION OF PERSONALIZED FEEDBACK IN THE PROGRAMMING STUDIES COURSES
The use of automatic feedback can significantly increase the success of beginners in programming, especially for those who have to study inside a large group, and the teacher’s time is limited. The article proposes an approach to the creation of automatic feedback based on previous solutions. The approach is to form a solution space of programs – weighted graph. The nodes in the graph are the program code; the edge weight is the number of changes and actions that need to be performed in order to go from one state to another. To reduce the number of unique solutions, the source code is normalized using a number of transformations and the construction of an abstract syntax tree. Feedback is a hint of the next step, which can be generated after a new solution is added to an existing graph and the path leading to a more correct state is identified. Thus, with the help of feedback you can reach the right decision. Using the solution space also allows you to find out which solutions are most common, which errors occur and which ways they can be corrected students prefer. Since this approach is based solely on data, the teacher does not need significant interaction with, which makes it scalable and adaptable.
Keywords: intelligent tutoring system, programming courses, automatic feedback, educational data mining, learning analytics.
MODEL OF DYNAMIC CROP ROTATION ON THE BASIS OF THE BELLMAN EQUATION WITH FINAL HORIZON
U.S. Skvortsov, N.A. Ryndin, K.A. Amoa
The problem of the study is to determine the optimal plan for multiple periods, which take into account the economy of the object of study in a dynamic structure. As a result, this article describes a dynamic model based on the Bellman equation with a finite horizon. The object of the study is crop rotation. By maximizing the net present, expected current and future returns, the modified Bellman equation provides optimal crop planting solutions. This model takes into account perennial crop rotations with a different set of crops. The Bellman equation is a partial differential equation with initial conditions given for the last time instant for the Bellman function, which expresses the minimum value of the optimization criterion that can be achieved, provided the system evolves from its current state to some final state. Using the Matlab package, a dynamic model of crop rotation was simulated. MATLAB uses the CompEcon toolkit for solving problems of dynamic programming with discrete time or with a discrete variable. Given the final value of the current and expected profits, the problem is solved by repeatedly applying the Bellman equation.
Keywords: :Markov model, dynamic programming, Bellman equation, crop rotation optimization.