ISSN 0236-235X (P)
ISSN 2311-2735 (E)


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Publication date:
16 June 2019

Latest issue articles

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Public date | Title | Authors

1. Problem solving experience in data visualization using ArcGIS software [№1 за год]
Author: Youssef Al-Damlakhi
Visitors: 188
Most users of geographic information systems (GIS) software, in particular, ArcGIS, which is considered one of the most com-mon GIS programs for implementing various applications and visualizing 3D data, do not pay much attention to input data com-patibility. This is also the case of the coordinate systems and projections that are the basis of working in GIS. Therefore, some-times specialists who work with GIS programs without experience or knowledge in cartography have problems. Thus, the ability of GIS users to have basic knowledge of GIS related sciences such as cartography and geodesy is important. The paper introduces some of the ArcScene program capabilities for visualizing and displaying 3D data. In addition, it dis-cusses most frequent difficulties in this field. For example, when displaying 3D data in ArcScene program or when displaying the slopes of the earth's surface based on the data of the DEM (Digital Elevation Model) layer. The paper also describes in detail the reasons and ways to resolve such difficulties.

2. Algorithmic and software implementation of a cognitive agent based on G. Polya’s methodology [№1 за год]
Authors: S.S. Kurbatov, Fominykh I.B., A.B. Vorobev
Visitors: 340
The paper describes an original approach to creating an integrated problem solving system (cognitive agent). The system in-volves a tight integration of linguistic processing stages, an ontological representation, a heuristically oriented solution and visu-alization. The system concept is based on the Polya’s methodology interpreted in algorithmic and software implementation. The system is implemented in a mock-up version and tested in the subject area “school geometry”. The linguistic component uses the problem canonical description obtaining method through paraphrasing and mapping it into a semantic structure. An automated solution search is based on implementing the rules that reflect the axioms of the respective subject areas. The heuristics presented in the ontology define the rules. The heuristics are designed as semantic network structures, which allows organizing a rule multiple-aspect search and selection justification as a natural language comment. Conceptual (cognitive) visualization provides the solution visual representation by interpreting a text file with information to display graphical objects, as well as comments on the solution process. Comments include natural language descriptions of rules (axioms, theorems), heuristic and empirical justifications for their choice and links to visualized objects. The paper defines experiments that demonstrate visualization possibilities of task drawings and ontology fragments, natural language phrases, mathematical and formal logic formulas. The ontology is implemented in the DBMS Progress. Visualization programs are implemented in JavaScript using JSXGraph and MathJax. The implementation provides a step-by-step solution view in different directions with dynamic changing in drawing and related comments. The authors have interpreted experimental results and planned the study to develop the described approach.

3. Flexibility of using input and output parameters of standard and non-standard functions in MatLab [№1 за год]
Author: O.G. Revinskaya
Visitors: 272
Based on a review of recent papers, the paper reveals the contradiction between the understanding of the breadth and flexibility of using input and output parameters of standard functions and the feeling of rigid predetermination when describing and using similar parameters of non-standard MatLab functions. This contradiction is resolved by a detailed analysis of the capabilities provided by MatLab (including its latest versions), so that the function parameters (when it is called) are interpreted as mandatory or optional, positioned or unpositioned, typed or untyped, etc. This variety of properties of input and output parameters provides flexibility in the application of standard MatLab functions. It is shown that by default MatLab controls only formal excess of the number of parameters used when calling a function (standard, non-standard) over the number of corresponding parameters specified in its description. For the parameters of a non-standard function to have certain properties, it is necessary to organize a function body program code in a special way: to check how many parameters are specified when the function is actually called, what type of information enters the function and exits through parameters; to analyze which optional parameters are set and which are not, etc. Such organization of the function body has been remaining very laborious for a long time. Therefore, the latest versions of MatLab have standard functions that auto-mate some of the performed operations. Thus, the article systematizes a set of measures that allow the parameters of a non-standard function to have the same breadth and flexibility of use as the parameters of standard MatLab functions. Based on personal experience in applied programming and teaching MatLab, the author shows simple examples that illus-trate in detail how to write non-standard functions with parameters that have the appropriate properties.

4. CAD integration for logic synthesis using global optimization [№1 за год]
Authors: P.N. Bibilo, V.I. Romanov
Visitors: 375
The paper proposes a technology for designing digital devices. This technology allows logical modeling of VHDL descriptions of combina-tional logic, forming the corresponding systems of Boolean functions, their logical optimizing and synthesizing logic circuits in various tech-nological libraries of logic elements. The software integration within this technology is based using scripts and BAT files that are supported by modern CAD systems. The source VHDL descriptions can set algorithmic and functional descriptions. They are truth tables of completely or noncompletely specified Boolean function systems, systems of partial Boolean functions, systems of disjunctive normal forms, descriptions of multilevel log-ical equations. In addition, structural descriptions of logic circuits synthesized in various target technological libraries might also be used as source VHDL descriptions. In this case, they are redesigned into another basis of logical elements. The transition from VHDL descriptions to systems of Boolean functions is based on logical simulation for all possible sets of input varia-bles. Logical optimization includes using of powerful programs of joint and separate minimization of Boolean function systems in the class of disjunctive normal forms, as well as programs of minimization of multilevel BDD representations (BDD – Binary Decision Diagram) of Boolean function systems based on Shannon’s expansion. A user only needs to specify a VHDL source description, a logical optimization method and a target library of logic elements used in the LeonardoSpectrum synthesizer. The required BAT file is generated automatically. The file provides synthesis using global logic optimization. The user can assess the solution found by comparing with another one that the LeonardoSpectrum synthesizer obtained from the original de-scription without prior optimization.

5. Fuzzy set approach for IT project task management [№1 за год]
Authors: A.R. Diyazitdinova, N.I. Limanova
Visitors: 429
Resource distribution and allocation problems are complex multi-criteria tasks. Therefore, the problem of development of effec-tive and universal technologies of work assignment among performers turns out to be challenging in software project manage-ment. One of the possible solutions to increase the relevance of project management decision-making in software development companies might be fuzzy logic. It allows processing semi-structured and inaccurate information using a natural language. The paper proposes a model of fuzzy production system to manage IT project tasks that allows operating natural language categories to improve the efficiency of decision making under uncertainty and cost cutout in the extreme. The authors consider software product development features; develop a typical logic of IT project tasks management process; prove fuzzy logic tech-nology application reasons are for project management. Implementation of fuzzy logic mathematical tools technique allows a project manager to operate variables represented in quality categories without transferring to mean values that enables decision-making quality increase. The paper considers a problem of task (ticket) development performance evaluation. There are derived six input linguistic variables and one output. There are developed term sets and membership functions for each of them. The built expert rule base includes 81 production rules. A model of fuzzy logic production system model for tasks management has been implemented us-ing Fuzzy Logic Toolbox for MatLab. The Mamdani algorithm has been used for fuzzy inference. The provided results of the model functioning would be useful for IT project managers.

6. Using the Bayes' theorem within software quality evaluation according to ISO/IEC 9126 standard [№1 за год]
Authors: D.P. Burakov , G.I. Kozhomberdieva
Visitors: 326
The paper discusses a way to use the approach based on well-known Bayes rule to evaluate software quality according to quali-ty model and evaluation process described in the ISO/IEC 9126 standard. In addition, it briefly describes software quality mod-els and evaluation process that are proposed by the abovementioned standard, as well as by the improved ISO/IEC 25010:2011 standard. The authors define the field of using the proposed approach during the evaluation process. The software quality evaluation is presented as a probability distribution on a set of hypotheses that software quality has reached one of the predefined quality levels proposed by the model. The Bayes' formula is used to build a posteriori probability distribution based on revised and refined during quality evaluation a priori probability distribution that is defined before evalua-tion. The source data for calculating probabilities is the results of measurement of heterogeneous quality metrics for arbitrary set of quality attributes that are specified in the software quality model. The proposed approach allows using both directly measured metrics and the metrics estimated by experts. In fact, the ap-proach gives reasonable software quality evaluation even if there are incomplete, inaccurate and inconsistent quality metrics.

7. Computer simulation of physical interactions of technical surfaces at the micro-level [№1 за год]
Authors: A.A. Rachishkin, Bolotov A.N., O.V. Sutyagin
Visitors: 191
The paper presents the software design for computer simulation of physical interactions of engineering surfaces at the micro level. It describes general principles of the system and analyses several simulated physical processes. It also considers contact interaction of rough surfaces including those with functional coatings. It calculates frictional parameters under various operating conditions and the thermal resistance of microindented joints of various machine parts. A flexible algorithm of the program and an independent segmented mathematical logic are developed for the optimal calcu-lation of simulated processes using numerical methods. Input data is based on micro-geometric and physical-mechanical proper-ties of real surfaces. This allows adjusting the model considering most technical surface properties. Developing software for simulation of contact interaction of technical surfaces makes it easier to solve engineering tasks and reduces the amount of re-sources needed for research. The software is divided into separate modules. The definition of general principles for each module development is benefi-cial for the horizontal scaling of a system for modeling physical interactions. This approach allows optimizing the number of in-put and output parameters, adding and modifying existing algorithms and configuring only necessary modeling processes. A modular structure optimizes the software development process. Due to the ability to remove and modify individual program modules without affecting the overall structure, it is possible to solve a wide range of engineering tasks effectively. The paper gives some examples of module operation for contact and friction interactions, as well as modeling thermal re-sistance of joints. The general algorithmic logic and the inherited surface topography data allow modeling these physical processes as real as possible.

8. A constructive learning method for artificial neural networks with weighted rates [№1 за год]
Author: M.A. Kazakov
Visitors: 230
The paper proposes a constructive method for teaching artificial neural networks with different correction parameters for neu-rons added at different stages of training. This method allows dealing with local minimization and at the same time controlling a neural network scale. It is assumed that dealing with local minimization might become more effective due to the difference in the learning rate, when the neurons added at later training stages are adjusted more intensively than the neurons added at early stages. The paper presents statistical data obtained in MNIST examples using the proposed method, the standard gradient descent method and the constructive teaching method. There is a Python program that has been developed using the numpy and matplotlib libraries in order to conduct numerical experiments that allow comparing the considered methods. A neural network is a direct distribution network, where the neuron inputs are connected to all the outputs of the previous layer. The activation function for all neurons is an exponential sigmoid. The training has been carried out by the method of back propagation of errors. The sum of squares of distances between output signals and reference values has been used as an evaluation function. The paper describes study conditions in detail and provides a graph illustrating the dynamics of the decline in the evaluation function value for all three methods. It is also assumed that the proposed method will reduce the impact of the learning process on the new data class on the effectiveness of the neural network in the classes that the network has learned at the early stages.

9. The methodology and algorithms of aerial object classification by the decision support system under intense information influence [№1 за год]
Authors: Dopira R.V., A.V. Getmanchuk, Potapov A.N., M.V. Semin, V.Yu. Semenov
Visitors: 211
The paper considers the development of methodology and algorithms for classification of aerial objects by a decision support system of the automated control system under intensive information influence. In case of such influence, the signs of system information overload are the amount of data on the air situation (marks from aerial objects) and the information quality. When solving the problem of object classification according to the catalog under parametric uncertainty and class intersection, the use of the sequential normalization procedure based on the entropy maximization principle allows obtaining the least doubtful dis-tribution of probabilities of classifying each of the objects to known or new classes. The paper proposes a combination of the basic method with the basic principles of the methods of split up standards and cluster analysis. The combination allows improving classification characteristics. The basis of the developed methodology of aerial objects classification by a decision support system under intensive information influence is the introduction of the con-cept of parametric space into the basic method, as well as the representation of classification objects and classes from the cata-log of reference values. At the same time, each of the main stages of the methodology analyzes the mutual location of the pro-cessing objects relative to each other, as well as relative to the classes from the catalog of reference values. The classification matrix is presented in the form of a set of dynamic lists. It allows reducing computational complexity while excluding matrix zero elements from processing and not allocating memory to store them. The functionality of processing classification results is extended. There is a possibility to fill in the catalog of reference values with the latest information. The decision support system, which implements the new methodology, allows the automated control system staff to assess the situa-tion in detail and to adjust the automated control system work as the empirical knowledge is formed.

10. Simulation of messages transmission between moving objects in a transport environment [№1 за год]
Authors: S.V. Rudometov, O.D. Sokolova
Visitors: 183
In recent years, there have been a lot of research in the development of wireless networks connecting vehicles. To connect ve-hicles to each other, as well as to connect them with roadside equipment, there are wireless networks that have are based on the principle of mobile ad hoc networks (Vehicular Ad Hoc Network (VANET)). The paper considers modeling of traffic in the transport network segment and data transmission from one node located on a moving object to other traffic participants. To simulate the movement of vehicles and message transmission, the Manufacturing and Transportation Simulation System (MTSS) is used. The system has been developed earlier by one of the authors. The MTSS allows visual building of simulation models of technological systems and conducting various simulation tests with these models. The paper considers MTSS simulation. The MTSS includes transceiver devices installed in moving objects (cars) or in sta-tionary objects located along the route. The authors study data transfer in this network - message transmission between cars (for example, an emergency message). The paper considers two options of a transport network segment that are: straight-line (high-way) and a square with road intersections. Experimental data show that the interference role in message transmission in a straight-line segment is not as significant as in a segment with road intersections.

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