Programming languages
Reference:
Gusenko M.
The use of regular expressions for decompiling static data
// Software systems and computational methods.
2017. № 2.
P. 1-13.
DOI: 10.7256/2454-0714.2017.2.22608 URL: https://en.nbpublish.com/library_read_article.php?id=22608
Abstract:
The subject of the study is the process of decompiling the source code of programs into high-level languages. The author shows the decompilation point in the program transformation cycle which includes the processes of canonization, compilation, optimization, and decompilation. The object of the study is the compiled equivalent of the static data description on a high level programming language, which in general case is a nontrivial mapping of syntactic constructions on a high level programming language into a byte sequences located in executable program modules and constructed considering various optimization techniques for this microprocessor architecture. The paper reviews the static data decompilation process as reconstruction of the parse tree of the program, which is recovered during the analysis of its executable code and as a binary sequence in the memory of the von Neumann machine, which is analyzed by the regular expression created by the decompiler from the supposed description of the data. Regular expressions are traditionally used to analyze character sequences. The article presents another area of application of this tool – for proving the hypothesis that this byte array of the executable module is the equivalent of compiled static data. The author suggests a variant of the corresponding syntax of the regular expression language. The article shows that the proposed method can be used to further verify the quality of the decompiled code.
Keywords:
object code, executable module, compilation, program language, regular expression, decompilation, reverse translation, translation, program parsing tree, data definition
Educational software systems
Reference:
Galimov A.A., Shabalina O.A.
Web-based design system for the modular educational programs in higher education.
// Software systems and computational methods.
2017. № 2.
P. 14-21.
DOI: 10.7256/2454-0714.2017.2.23095 URL: https://en.nbpublish.com/library_read_article.php?id=23095
Abstract:
This article is devoted to the design of information and software support for the development process for а web-based system of the educational programs at the university level .The need to develop it is due to the requirements for the educational programs under the current federal state educational standards for the higher education. These standards establish that the results of training are defined as an integral system of competences. Additionally, the article outlines the approach to the development of educational programs satisfying the requirements of the competence paradigm, upon which the basis of the system is being developed. The research is based upon the following methods: systemic analysis, graph theory, combinatorial-ordered modeling and dynamic programming. The scientific novelty of the research involves the development of a model for a learning resource formed as a hierarchy of knowledge spaces. This model of representation provides modular flexible structure for the learning resources developed on its basis, which is achieved by combining in the model the properties of hierarchical and algebraic structures.
Keywords:
learning resources design, higher education program, knowledge space, lattice, lattice-theoretical approach, knowledge domain model, knowledge space extendibility, knowledge space fragmentability, web-based system, learning resource
Knowledge Base, Intelligent Systems, Expert Systems, Decision Support Systems
Reference:
Dolzhenko A.I., Shpolyanskaya I.Y.
Fuzzy model and algorithm for assessing the quality of web services integrated into the service oriented architecture of an information system.
// Software systems and computational methods.
2017. № 2.
P. 22-31.
DOI: 10.7256/2454-0714.2017.2.23098 URL: https://en.nbpublish.com/library_read_article.php?id=23098
Abstract:
Selection of appropriate web services is an important step in the development of service-oriented architecture (SOA) for an information system. When selecting a web service, the quality of service criteria (QoS) are used regularly. These criteria characterize the non-functional properties of web service candidate. However, the functional characteristics of the service that are difficult to quantify, and the factors of the effectiveness of the lifecycle management of composite architectures are also important. The article discusses the comprehensive approach to evaluation and selection of web services in SOA development on the basis of factors related to non-functional and functional requirements and taking into account the economic efficiency evaluation of implementation and use of service-oriented applications. The choice of service is performed via fuzzy models for integrated assessment of the web service quality. The developed model and algorithm of web service quality evaluation and its software implementation will allow to realize decision support procedures for substantiation and choice of an appropriate structure of SOA-based information system in the situation of incomplete information.
Keywords:
QoS, functional requirements, integrated evaluation of quality, non-functional requirements, economic efficiency evaluation, fuzzy model, decision-making support, web services, SOA, Service-oriented architecture
Mathematical models and computer simulation experiment
Reference:
Oleinikova S.A.
A mathematical model of a complex serving system with stochastic parameters and mutual dependency between the jobs.
// Software systems and computational methods.
2017. № 2.
P. 32-44.
DOI: 10.7256/2454-0714.2017.2.22457 URL: https://en.nbpublish.com/library_read_article.php?id=22457
Abstract:
The object of research in the work involves the complex service systems, which are characterized by mutual dependence between the works, their random duration and necessity of rationalize recourses in time. These features stipulate the development of a mathematical model which is meant to form the basis for the optimization task of forming a schedule. As the objective function, a generalized criterion that allows the most efficient allocation of resources over time is chosen. An important parameter of this model is the duration of the service. The assessment of this parameter is an important task, since it directly affects the accuracy of the developed schedule.The formation of a mathematical model is based on the apparatus of probability theory and the theory of project management. To find the duration of the service a cubic equation connecting the variance, the expectation and the mode of the cubic equation was obtained. As a result a mathematical model a mathematical model designed for describing multi-stage servicing systems with a stochastic duration of maintenance of mutually dependent works was found by the authors. This model may be used to describe a whole class of systems with the above features in the case where it is necessary to efficiently allocate resources over time. Novelty is present in the use of a generalized resource criterion in conjunction with resource and time constraints. The author also finds an evaluation of service time, which is distinguished by increased accuracy in comparison with existing analogues.
Keywords:
mathematical model, tochastic parameters, mutual dependence of works, random duration of service, resource criterion, time constraints, PERT, beta distribution , expected values, project management
Mathematical models and computer simulation experiment
Reference:
Toropov B.A.
Game-theoretic centrality in the graph nodes based upon the Shapley vector.
// Software systems and computational methods.
2017. № 2.
P. 45-54.
DOI: 10.7256/2454-0714.2017.2.22647 URL: https://en.nbpublish.com/library_read_article.php?id=22647
Abstract:
The object of studies concerns the methods for evaluation of the graph nodes. The author pays attention to the fact that the existing centrality metrics, such as level centrality, closeness centrality, interval centrality, own vector, etc., are sometimes not suitable for modeling the situations, when graph nodes are social object models, and therefore, they are capable of cooperation in order to achieve social goals. In this case game-theoretic centrality models (such as coalition games models) are better suited to reflect the modeling object. The methodology of the study involves the elements of graph theory, probability theory, as well as the apparatus for the analysis of social networks as a new independent scientific sphere. The key result of the stuy is that game-theoretic centrality based upon the Shapley vector is a flexible and mostly universal instrument for the social graph analysis. It allows to consider an unlimited set of quality characteristics of the graph nodes, as well as their topological qualities in any combination in order to evaluate the nodes.
Keywords:
algorithm, permutation, Shapley vector, coalition games, group centrality, level centrality, node centrality, social network, social graph, graph
Computer graphics, image processing and pattern recognition
Reference:
Pritykin F.N., Khomchenko V.G., Glukhov V.I., Nefedov D.I.
Geometrical analysis of current situations characterizing the position of environment manipulator based upon the use of the permitted configuration spheres.
// Software systems and computational methods.
2017. № 2.
P. 55-66.
DOI: 10.7256/2454-0714.2017.2.22685 URL: https://en.nbpublish.com/library_read_article.php?id=22685
Abstract:
The immediate object of studies is the module for automatic detection for the manipulator mechanism collisions with the prohibited zones, which is used in intellectual robot guidance. The object of studies involves geometrical analysis characterizing the position of the manipulator mechanism and the known prohibited zones. The authors provide detailed analysis of analytical value of the allowed configurations sphere within the space of generalized coordinates with two prohibited zones present in the working space of a manipulator. The generalized coordinates space is provided for by the axes of the rectangular coordinates system based upon the directions of angles providing for the movements in the turning pairs. It is offered to use the sufficient condition for the collisions based upon the usage within the space of allowed configurations. All of the allowed configurations within the generalized coordinates space are reflected by a geometrical object. The said geometrical object is provided for via analytical means with the use of several kinematic surfaces limiting it. The main result of the study is shorter calculation period for test assignments regarding virtual modeling for the manipulator movement of a "Komodo dragon" mobile robot with the use of the detection algorithm for collisions between the mechanism and the environment. The special input of the authors into the issue involves the development of the knowledge database assignment, which is used for intellectual guidance for manipulator motion in the familiar environment. The novelty of the study is due to the development of the more productive method of information analysis on the position of manipulator mechanism and prohibited zones based upon the analytical dependencies, which are used to establish the allowed configuration space. The use of this space for the trajectory synthesis within the generalized coordinates space allows one to correct the manipulator motion in order to predict and to exclude the dead-end situations when synthesizing the velocity vector movement.
Keywords:
kinematic couples, intelligent robots, restricted areas, knowledge base, the virtual model operation of movements, kinematic surfaces, geometrical analysis, robot traffic control, area of allowed configurations, space of generalized coordinates
Computer graphics, image processing and pattern recognition
Reference:
Varepo L., Khomchenko V.G., Glukhov V.I., Pritykin F.N., Krivokhat'ko E.A.
Geometric modeling of the hinged mechanisms in the third class of cyclic automatic machines for moving working bodies with approximate stops in two extreme positions.
// Software systems and computational methods.
2017. № 2.
P. 67-75.
DOI: 10.7256/2454-0714.2017.2.22719 URL: https://en.nbpublish.com/library_read_article.php?id=22719
Abstract:
The objects of the study are articulated lever mechanisms based on the use of third-order third-class structural groups by the Assur-Artobolevsky classification. These mechanisms are studied and designed as actuators of high-performance machines. Of the many lever mechanisms of the third class, the so-called limit-forming mechanisms are singled out to become the object of studies, making it possible to obtain approximate outgrade of the output link, and, consequently, of the working tool by using the limit positions of the lever diads. The third class articulated lever mechanisms of the third class are being analyze, due to their kinematic features these mechanisms allow to provide approximate out-riggers of the output link in both its extreme positions in accordance with the preassigned operating schedule of the machine.The method of the study of hinged mechanisms with approximate stops of the out-put link in the two extreme positions according to the given cyclogram is the method of constructive geometric modeling as the basis for the development of an analytical geomet-ric model of the mechanisms under consideration. Based upon the constructive geometric modeling the authors propose the method for designing six-link mechanisms of the third class with two approximate stops of the output link in the extreme positions according to the preassigned cyclogram. Possible branching of the kinematic scheme of this mechanism is revealed. An analytical geometric model for the synthesis of six-link hinged mechanisms of the third class as executive devices for high-performance machines for printing, food, textile and a number of other industries has been created by the authors.
Keywords:
dwells, free parameters, Chebyshev approximation, working body, geometric construction, branching, cyclogram, kinematic scheme, hinged mechanism, Geometric modeling