“Systems and Means of Informatics” scientific journal

Volume 33, Issue 4, 2023

Content   Abstract and Keywords   About Authors

REPLACING SYNCHRONOUS TRIGGERS WITH SELF-TIMED COUNTERPARTS DURING CIRCUIT DESYNCHRONIZATION

• Yu. A. Stepchenkov
• D. Yu. Stepchenkov
• Yu. G. Diachenko
• N. V. Morozov
• L. P. Plekhanov

Abstract: Self-timed (ST) digital circuits have a number of advantages in comparison with synchronous counterparts and become a promising basis for the reliable computing systems implementation operating in extreme conditions.
The lack of effective tools for automated synthesis of ST circuits convenient for use by developers trained in computer-aided design of the synchronous circuits significantly hinders the introduction of ST circuits into digital circuit development practice. The approach to the ST circuit synthesis based on the transformation of the original synchronous Verilog description of the circuit operation algorithm into the ST implementation according to formalized rules in automatic mode with minimal interactive participation of the developer provides a quick ST solution with acceptable characteristics and does not require deep knowledge of self-timing from the designer. It relies on the basic principles of ST circuits design and heuristic methods for their development. One of the important and controversial stages of ST circuit design in this approach is the replacement of synchronous latches and flip-flops by their ST counterparts. For this purpose, the authors propose to use the method of tabular formalized correspondence based on a ready-made library of ST latches and flip-flops and analysis of their environment.

Keywords: self-timed circuit; logic synthesis; trigger; Verilog; substitution; coincidence table

CHARACTERISTICS AND LOGICAL STRUCTURE OF THE METHODOLOGY FOR CONSTRUCTING REFLEXIVE-ACTIVE SYSTEMS OF ARTIFICIAL HETEROGENEOUS INTELLIGENT AGENTS

• S. V. Listopad

Abstract: The paper describes the elements of the methodology for constructing reflexive-active systems of artificial heterogeneous intelligent agents, namely, its characteristics and logical structure that form the basis for constructing of its temporal structure (life cycle). Artificial heterogeneous intelligent agents of reflexive-active systems mutually model each other's reflexive positions, dynamically develop tactics and strategies of their behavior relevant to the models of their counterparties, as necessary, in the process of solving problems, attract new agents from the pool of available agents built by various developers, and exclude existing agents from their composition, rebuilding "on the fly" the composition of agents and the structure of connections between them.
The development of such systems for solving practical problems will provide new theoretical, methodological, and technological knowledge about collective intelligence, increase the relevance of these systems to real teams of specialists, and verify the knowledge about collective processes and effects in small groups.

Keywords: reflection; methodology; reflexive-active system of artificial heterogeneous intelligent agents; hybrid intelligent multi-agent system; team of specialists

AUTOMATA MODELS OF FAULT PROPAGATION AND SELF-HEALING

• A. A. Grusho
• N. A. Grusho
• M. I. Zabezhailo
• V. O. Piskovski
• D. V. Smirnov
• E. E. Timonina

Abstract: The papers devoted to information security analysis often discuss the damage caused by attacks on computer systems and information resources but little attention is paid to how hostile attacks and their failures affect business processes and create serious threats to the activities of business systems as a whole.
The idea of terrorists - low impact entails great damage - is the main goal of hostile influence on the business system. While studying the problems of the propagation of failures and hostile impacts, dependencies in the business system and cause and effect relationships play the basic role. Finite automaton has been selected to simulate the interaction processes of the business system's subsystems.
A mechanism for recovering the subsystem from a failure has been built. In the causal scheme, a failure propagation model is built in the presence of a mechanism for recovering each automaton after the failure. It is shown that despite the rapid recovery from a failure for each subsystem of a large system, a global failure may occur due to out-of-sync or due to the appearance of too many queues at critical controls.

Keywords: information security; fault propagation; cause-and-effect relationships; automata model of system presentation

CALCULATION OF AVAILABILITY TARGETS FOR ITER DIAGNOSTICS

• G. M. Konovalov

Abstract: The article is devoted to the problem of setting availabilities for diagnostic systems (diagnostics) in the ITER (International Thermonuclear Experimental Reactor) project. Such systems should provide the required level of availability with which numerous parameters of the ITER are measured. A number of difficulties arise on the way of problem formulation and its solution. These include, in particular, the uniqueness of the object, the variety and multiplicity of parameters and diagnostics, the complex interrelation between them, and the absence of analogues in the reliability literature. The paper presents the results of modeling using the developed earlier mathematical model and the computational algorithm. Also, by the example of a simplified model of the ITER diagnostic complex, the sensitivity to the values of empirically set coefficients is analyzed. The obtained results can be used by the developers of various diagnostic subsystems of ITER in the form of defined requirements.

Keywords: ITER; mathematical models of reliability; large system reliability analysis; availability

ALGORITHM FOR GLOBAL OPTIMIZATION OF TIME-RELATED STATIONARY CHARACTERISTICS OF JOBS IN NONOBSERVABLE PARALLEL QUEUES

• M. G. Konovalov
• R. V. Razumchik

Abstract: Consideration is given to the model of a stochastic system comprised of a finite number of parallel independently running queues with heterogeneous servers, a single flow of independent jobs, and a single dispatcher which possesses full a priori information about the system's parameters and its initial state. At any moment, the dispatcher does not have any feedback from the queues but can memorize its previous routing decisions and time instants at which the decisions were made. Under quite general assumptions about the jobs' interarrival and jobs' size distributions and queues' scheduling, the (policy gradient) algorithm is proposed which allows one to locate the global optimum of the job's stationary mean sojourn or waiting time. The algorithm is based on the assumption that one can reach the neighborhood of the global optimum by applying the dispatching policy with a finite memory.

Keywords: parallel service systems; dispatching; control under incomplete observations; program control

QUEUING MODEL FOR CHOOSING eMBB BIT RATE LEVELS UNDER URLLC PRIORITY TRANSMISSION IN A 5G NETWORK

• E. D. Makeeva
• I. A. Kochetkova
• V. S. Shorgin

Abstract: Fifth generation (5G) wireless networks are characterized by joint transmission of ultrareliable low-latency communications (URLLC) and enhanced mobile broadband (eMBB). URLLC is often small in size and can take up part of a resource block. The paper analyzes a scheme for joint URLLC and eMBB transmission in the form of a queuing system with priority admission control with the ability to reduce bit rate and interrupt eMBB transmission when URLLC arrives. Numerical analysis of the problem of selecting eMBB traffic transmission rate levels to maximize the eMBB bit rate taking into account restrictions on the eMBB blocking and service interruption probabilities was performed.

Keywords: 5G; eMBB; URLLC; queuing system; priority admission control; interruption; bit rate degradation

ANALYSIS OF JOINT USAGE OF ENERGY CONSERVATION STRATEGIES FOR 5G DEVICES WITH REDUCED CAPABILITY

• V. A. Beschastnyi
• E. S. Golos
• D. Yu. Ostrikova
• E. A. Machnev
• V. S. Shorgin
• Yu. V. Gaidamaka

Abstract: The recently standardized Reduced capability (RedCap) user equipment (UE) type for 5G systems, New Radio (NR), supports new mechanisms to limit power consumption. Using a combination of Discontinuous Reception (DRX), Wake-Up Signal (WUS), and Radio Resource Management (RRM) relaxation techniques, RedCap-enabled UEs can provide high energy efficiency while meeting the speed requirements for a large set of applications. The present authors investigate the impact of the above mechanisms on the energy consumption of UEs in 5GNR networks. To this aim, the authors propose a mathematical model that captures the specifics of these mechanisms and environmental and deployment characteristics. Energy efficiency and battery life time are considered as the main characteristics. The numerical results demonstrate that combining all the considered energy saving mechanisms allows to improve the battery life time by 15%-20%. The WUS mechanism shows better performance as compared to the RRM relaxation. These conclusions hold for a wide range of input system parameters, including packet interarrival time and blockers density.

Keywords: 5G; New Radio; DRX; RedCap; WUS; RRM relaxation

METHODS FOR OPTIMIZING THE SPEED OF PERFORMING FUNCTIONAL REQUESTS IN AUTOMATED INFORMATION SYSTEMS TAKING INTO ACCOUNT THE SEMANTIC ANALYSIS OF INFORMATION

• T. K. Biryukova
• M. M. Gershkovich

Abstract: The article suggests the ways to increase the speed of execution of functional queries to databases in large automated information systems (AIS). The cascade principle of information accumulation when each node of a hierarchical territorially distributed AIS receives and accumulates all data from "lower" nodes, allows optimizing the traffic on communication channels between user workstations and databases. In some cases, this principle also increases the efficiency of search queries. In order to further accelerate the execution of queries, the authors propose a method for distributing data among physical storage media depending on the semantic content of the information. The authors recommend storing the "search data" on high-speed and high-capacity physical media. "Display-only" data may be stored on relatively slow and cheap (conventional) media. Since the performance of servers affects the speed of performing search queries and a part of server resources is spent on database backup, it is important to choose the optimal backup method. The authors propose to set up protocols (procedures) for data backup depending on the type of information.

Keywords: automated information system; information-analytical system; communication channel; information exchange; database design; database query; query optimization; database backup

METHOD FOR COMPUTER MODELING OF ELASTIC CHARACTERISTICS OF MULTILAYER COMPOSITE MATERIALS

• K. K. Abgaryan
• N. L. Zagordan
• Y. D. Mochalova

Abstract: Modern polymer composite materials are widely used in the aerospace industry. Creation of new materials with the required characteristics is one of the most important directions for the development of the industry, especially in connection with the need to quickly resolve the issues related to import substitution. The paper presents the results of calculation of the effective elastic characteristics of multilayer polymer composite materials with differently oriented layer reinforcement structure. The model of reinforced material based on the assumption that the composite material consists of quasi-homogeneous transversally isotropic perfectly connected layers is used. The obtained calculation results are in good agreement with both experimental data and the results of calculations of commercial packages and can be used to automate scientific and engineering calculations in the selection of components and methodology of their placement according to the given characteristics of polymer composite materials.

Keywords: computer modeling; multilayer polymer composites; elastic characteristics

SEARCH WITH EXCLUSION IN PARALLEL TEXTS

• A. A. Goncharov

Abstract: The paper examines the method of search with exclusion in parallel texts. The described method is based on the approach that takes a text as an ordered set of wordforms. In the context of this approach, the possibilities of bilingual search by exact form, by lemma, and by morphological features are considered. This approach provides a basis not only for the abovementioned types of search, but also for search with exclusion, i. e., a search allowing to find in parallel texts such pairs of text fragments that contain a certain wordform in language A but do not contain any wordform from a given set in language B. To illustrate this idea, an example of searching fragments with implicit logical-semantic relations in parallel texts stored in a database is given.
If the required wordform in language A marks a logical-semantic relation and the set of wordforms in language B contains the maximum number of variants for the translation of the required wordform into language B, the search can yield the pairs of fragments where the logical-semantic relation is expressed in the fragment in language A by the required wordform but it is implicit in the fragment in language B.

Keywords: bilingual search; search with exclusion; implicitness; knowledge extraction from texts; parallel texts; logical-semantic relations

GRAPH n-GRAMS IN THE TEXT ATTRIBUTION PROBLEM

• N. D. Moskin
• A. A. Rogov
• A. A. Lebedev

Abstract: The paper presents the results of research in the field of modeling the structure of texts using a generalized context-dependent graph-theoretic model. The object of the study is mainly literary and folklore texts for which the task of attribution arises. For example, there are many such texts in the works of the famous Russian writer F. M. Dostoevsky. The authors show how it is possible to build hybrid models based on dependency trees, graph models of syntactic structure of links between simple sentences in a multicomponent complex sentence, and "strong links" graphs of word combinations of different grammatical classes. Such models make it possible to construct new informative features that are potentially applicable in the attribution of texts. An example is the frequency of occurrence of graph n-grams which are generalizations of ordinary n-grams syntactic n-grams, and other similar constructions used in stylistic studies. The article also discusses the format for storing texts, their generalized graph models, and graph n-grams.

Keywords: artificial intelligence; text attribution; graph; metagraph; hybrid graph; folklore text; literary text; graph n-gram

SCIENTIFIC PARADIGM OF INFORMATICS: TRANSFORMATION CLASSIFICATION OF DOMAIN OBJECTS

• I. M. Zatsman

Abstract: A description is given of the first outcomes of creating a classification of transformations of objects of an informatics subject domain as a component of the scientific knowledge system covering a wide range of information and computer sciences. The boundaries of its subject domain which is thus significantly expanded are defined within the framework of Paul Rosenbloom's concept of polyadic computing. All informatics entities in the paper are divided into two global classes: objects and their transformations. For each such class, in the process of creating the scientific paradigm of informatics, its own classification is constructed and with their formation its creation began. This paper discusses the two top levels of only the classification of transformations of objects of the informatics subject domain. The basis for constructing the highest level is the proposed division of the informatics subject domain into media (mental, sensory, digital, and a number of other media), each of which includes objects of the same nature. At the same time, there are examples of the appearance of previously unused media in the informatics subject domain. Thus, with the creation of information technologies that use brain-computer interfaces, it would be logical to add the neuromedium to the informatics subject domain, and with the development of methods and means for long-term storage of large-volume data using synthesized DNA chains add the DNA-medium. The basis for constructing the next level of classification of object transformations is the Solomonick's typology of sign systems. The purpose of the paper is to describe, on the one hand, the two top levels of classification of transformations of objects of the informatics subject domain, and on the other hand, the method for generating tables detailing this classification which makes it possible to correlate the categories of object transformations in the tables with the interfaces implemented in computer systems and means. The generated tables include categories of transformations that correspond to both already known interfaces and theoretically possible ones but not yet implemented in computer systems and means.

Keywords: domain objects; transformation of objects; classification; subject domain medium; informatics paradigm

THEORY OF S-SYMBOLS: THE CLASSES OF BASIC S-PROBLEMS

• V. D. Ilyin

Abstract: The theory of S-symbols is an extended generalization of the theory of S-modeling. It is considered as a part of the methodological support for the development of artificial intelligence systems in the S-environment (including knowledge systems, systems of S-modeling of problems and program design, etc.). The S-environment based on interconnected systems of S-(symbols, codes, signals) serves as the infrastructural basis for the implementation of information technologies for various purposes. The article presents the fourth part (out of four) of the theory. The substantiation of the classes of basic S-problems is given and the main classes are defined: S-(representations, transformations, recognition, interpretation, construction, exchange, preservation, accumulation, search, information protection and cryptography). The S-problems to which other S-problems are reduced are called basic S-problem. The key S-problems of each class are considered.

Keywords: theory of S-symbols; S-problem; classes of basic S-problems; S-(representations, transformations, recognition, interpretation, construction, exchange, preservation, accumulation, search, information protection and cryptography)

CLASS IMBALANCE IN THE TECHNOLOGY OF CONCRETE HISTORICAL INVESTIGATION SUPPORT

• I. M. Adamovich
• O. I. Volkov

Abstract: The article continues a series of works devoted to the technology of concrete historical investigation support, built on the principles of co-creation and crowdsourcing and designed for a wide range of nonprofessional historians and biographers users. The article is devoted to the further development of the topic of data preparation for machine learning algorithms used in the technology.
The special importance of binary classification for concrete historical research is shown. The problem of class imbalance in binary classification using machine learning algorithms and its consequences are described. It is shown that concrete historical data can be highly imbalanced. An overview of approaches to solving the problem of class imbalance elimination is given. The analysis of the specifics of concrete historical data was carried out, and on its basis, the oversampling approach was chosen as the most suitable for the technology. Algorithms implementing this approach are described; their advantages and disadvantages are evaluated. The ADASYN algorithm has been selected as the most promising for use in the technology conditions. The possibilities of the already included in the technology means of data noise and outliers control to compensate such a disadvantage of the ADASYN algorithm as sensitivity to outliers are evaluated.

Keywords: concrete historical investigation; distributed technology; machine learning; class imbalance; ADASYN algorithm