Objectives. The aim of the work is to develop and analyze a formal model for describing complex linked coupling faults of memory devices and to formulate the necessary and sufficient conditions for their detection. The relevance of these studies lies in the fact that modern memory devices, characterized by a large amount of stored data and manufactured according to the latest technological standards, are distinguished by the manifestation of complex types of faults in them.

Methods. The presented results are based on the classical theory and practice of march tests (March tests) of memory devices. In particular, the paper uses formal mathematical models for describing memory faults and shows their limitations for representing complex linked coupling faults. The main idea of the approach proposed by the authors is based on the use of a new formal description of such faults, the key element of which is the introduction of roles performed by the cells involved in the fault.

Results. Three main roles are defined that cells of the complex linked coupling faults perform, namely the role of the aggressor (A), the role of the victim (V), as well as the role of both the victim and the aggressor (B), performed by two cells simultaneously in relation to each other. It is shown that the scenario for the implementation of the roles of memory failure cells is determined by the marching test used, and, first of all, by the address sequence used to access the cells. The procedure for setting a formal model of a linked fault is given, the basis of which is the roles performed by the cells included in the fault and the scenario specified by the test. A statement is given that determines, on the basis of a new formal description of linked coupling faults, the necessary and sufficient conditions for the detection of such faults. The presence of undetectable linked coupling faults is shown, and the conditions for their detection are formulated using multiple March tests. The conducted experimental studies have confirmed the validity of the formulated provisions of the article. On the basis of the classical example of a linked coupling fault, the fulfillment of necessary and sufficient conditions for its detection by a single march test is shown.

Conclusion. The results of the research confirm that the proposed formal mathematical model for describing linked coupling faults makes it possible to determine their detection by marching tests. Within the framework of the proposed model, the necessary and sufficient conditions for detecting linked coupling faults by marching tests that detect single coupled faults are determined.

Objectives. The problem of functional verification of control devices with respect to their design specification is considered. When solving the problems of implementing and testing of discrete systems, one has to deal with the presence of parallelism in the behavior of interacting control objects, which is also displayed in the assignment for designing control systems. The aim of the work is to develop a method for simulating descriptions of such systems, which allows their behavior testing dynamically on the area limited by their possible functioning.

Methods. The paper considers a class of control systems with parallelism of the processes occurring in them, which permits linearization of their execution. To specify the behavior of such control systems, it is proposed to use the PRALU language of parallel control algorithms, which is based on Petri nets and which allows to order events occurring during the device operation. An object-oriented approach to simulation of the description of the control algorithm at the transaction level is proposed. For this purpose, a TLM (Transaction-Level Modeling) model has been developed for describing the devices with behavior parallelism in PRALU language. The transaction level model describes a system as a set of interacting processes that run in parallel and determine the behavior of the system over time.

Results. The key concepts of the TLM model for simulating the descriptions of control algorithms in the PRALU language are defined: data structure, transactions, processes, and a barrier mechanism for synchronization of parallel processes. A method is proposed for transforming the description of an algorithm in the language into a TLM model, which is based on the representation of language operations as compositions of elementary operations that are performed sequentially. The set of these operations forms the basis for the algorithmic decomposition of a parallel algorithm in PRALU language into intermediate language program that is executed strictly sequentially. Translators of this program into the Verilog and C languages have been developed, the results of their compilation are simulators of the behavior of control system.

Conclusion. The proposed simulation method can be used to create a test bench for functional verification of the circuit implementation of control devices with behavior parallelism. In this case, test sequences for verifying the circuit implementation can be generated dynamically – in the process of simulating the description of the algorithm in the PRALU language directly the control device or system, which include the control algorithm and the algorithms of controlled objects behavior.

Objectives. The interaction between a "smart city" and digital economy can be explored and analyzed within the framework of the structural-parametric adaptation method. This method allows the adaptation of the parameters and structure of the system model to ensure optimal functioning in the conditions of changing external environment. The concept of a "smart city" can be examined based on the principles of structural-parametric adaptation, such as interoperability, decentralization, virtualization, real-time operation, modularity, and service orientation. Within the scope of structural-parametric analysis, a "smart city" is regarded as a complex multi-level cyber-physical system.

Methods. Structural-parametric adaptation methods and structural-parametric optimization methods are employed.

Results. A general form of the algorithm for structural-parametric adaptation of the system and a mathematical model of the problem of structural-parametric optimization of "smart city" systems have been developed.

Conclusion. To address the challenges of constructing, optimizing, and adapting the structure of a "smart city" system, it is necessary to consider the technical requirements of the system and the capabilities of the infrastructure used, and to apply the structural-parametric adaptation method.

Objectives. An exponential queuing network with single-line poles is considered, which differs from the Gordon – Newell network only that the waiting time for service requests at the poles of the network is a random variable with conditional distribution for a fixed number of requests at the pole as an exponential distribution. Requests at poles and requests that did not get the service are moving through the network in accordance with different routing matrices. The objective was to investigate a queuing system and to establish sufficient conditions for its ergodicity, also to find stationary distribution of given network.

Methods. Methods of mathematical modeling and analytical research of queuing networks are used.

Results. A theorem generalizing the Gordon – Newell theorem is proved.

Conclusion. The possibility of varying the routing matrices of served and unserved requests makes it possible to take into account a wide variety of practical situations and reduce the load in the bottlenecks of the network under study. It is very important in the design and modernization of information and computer networks.

Objectives. A variational-difference method for numerical simulation of equilibrium capillary surfaces based on the minimization of the energy functional is proposed. As a test task a well-known axisymmetric hydrostatic problem on equilibrium shapes of a drop adjacent to a horizontal rotating plane under gravity is considered. The mathematical model of the problem is built on the basis of the variational principle: the shape of the drop satisfies the minimum total energy for a given volume. The problem of the functional minimization is reduced to a system of nonlinear equations using the finite element method. To solve the system a Newton's iterative method is applied.

Methods. The variational-difference approach (the finite element method) is used. The finite linear functions are chosen as basic functions.

Results. Equilibrium shapes of a drop on a rotating plane are constructed by the finite element method in a wide range of defining parameters: Bond number, rotational Weber number and wetting angle. The influence of these parameters on the shape of a drop is investigated. The numerical results are matched with the results obtained using the iterative-difference approach over the entire range of physical stability with respect to axisymmetric perturbations.

Conclusion. The finite element method responds to the loss of stability of a drop with respect to axisymmetric perturbations. Therefore it can be used to study the stability of the equilibrium of axisymmetric capillary surfaces.

Objectives. The main purpose of the work is the experimental verification of the method of automatic threat modelling based on the ontological approach using the example of multicomponent container applications presented in the form of data flow diagrams.

Methods. Methods of ontological modelling and knowledge management are used in the work. The Web Ontology Language is used to represent knowledge; automatic reasoning based on description logics is used for threat modelling.

Results. A machine-readable set (dataset) of 200 data flow diagrams is developed; each diagram is obtained from the configuration of a real container application and is presented as an ontology and a knowledge graph. An ontological two-level domain-specific threat model of container applications is formed. An experiment is conducted to compare the coverage by threats using the common approach and using domain-specific threats for created dataset. For 95 % of the diagrams, the domain-specific threat model showed the coverage similar or greater than the common approach.

Conclusion. The results of the experiment prove the suitability and effectiveness of the ontological approach for automatic threat modelling. The created dataset can be used for various research in the field of automation of threat modelling.

Objectives. A prototype system for automated removal of homonyms in Belarusian and Russian electronic texts is described. This is due to the urgent problem of automatic text processing at the morphological level, the process of which is complicated by the inflection of the Belarusian language with a diverse and rich system of morphological characteristics of parts of speech.

Methods. The work uses regular homographs identification methods and knowledge-based methods.

Results. Methods and approaches for designing systems for automatic detection of homographs are proposed. An algorithm for identifying homographs on the basis of knowledge-based method has been developed. An effective and fast-acting prototype for their removal in Russian and Belarusian has been implemented.

Conclusion. A working prototype of the homograph search is presented, which is the first resource for removing ambiguity for the Belarusian language in open access.