   |
  |
||
|
|||
 |
|||
“Informatics and Applications” scientific journalVolume 18, Issue 3, 2024Content Abstract and Keywords About Authors MODELS FOR ANALYZING LAYOUT SCHEMES IN THE PROBLEMOF AIRCRAFT DESIGN
Abstract: The problems of analyzing the characteristics of the designed aircraft at the stage of its appearance formation are considered. The characteristic feature of these tasks is the lack of sufficient information about the aircraft design which appears only at the stages of preliminary and detailed design. In essence, these are the tasks of technical forecasting for a rather limited set of parameters that can be operated by the designer at this stage. The main task of image formation is synthesis of the aircraft layout scheme and construction of its parametric representation. Composition diagrams in design practice represent one of the main design documents and serve as a prototype of the developed product. The present work is devoted to the presentation of mathematical models designed to build estimates of weight, aerodynamic, flight and technical, take-off, and landing characteristics of the aircraft using the parameters of its layout and the subsequent verification of compliance of the obtained estimates with the requirements for the designed product. Keywords: mathematical modeling; design automation; aircraft; aircraft layout; aircraft characteristics STATISTICAL MODELING OF DIFFERENTIAL STOCHASTIC SYSTEMS WITH UNSOLVED DERIVATIVES
Abstract: The paper is dedicated to statistical modeling methodological support for differential stochastic systems with unsolved derivatives (StS USD). The basic results are: (i) two theorems concerning reduction of stochastic functional-differential equations to stochastic Ito equations; (ii) Euler approximation method for stochastic differential equations with Gaussian and Poisson noises; (iii) three theorems concerning numerical algorithms of various accuracy for StS USD with smooth nonlinearities; and (i.) two algorithms for StS USD with nonsmooth nonlinearities. Special attention is paid to methodological aspects of numerical statistical analysis of deterministic and random components in the cases of weak and strong approximation. Directions for further research are given. Keywords: analytical (probabilistic) modeling; methodological support; statistical modeling; stochastic systems (StS); StS with unsolved derivatives (StS USD) CONDITIONALLY OPTIMAL FILTERING IN STOCHASTIC SYSTEMS WITH RANDOM PARAMETERS AND UNSOLVED DERIVATIVES
Abstract: For observable differential Gaussian stochastic systems (StS) with random parameters in the form of multicomponent integral canonical expansions (MC ICE) and StS with unsolved derivatives (USD),methodological support for synthesis of conditionally optimal filters is presented. A survey in the fields of analytical modeling and sub- and conditionally optimal filtering, extrapolation, and identification is presented. Necessary information concerning MC ICE is given. Special attention is paid to mean square regressive linearization including MC ICE. The stochastic systems with USD reducible to differential are considered. Basic results in normal conditionally optimal filtering (COF) are presented for StS USD reducible to differential. The theory of COF application to StS USD with multiplicative noises is developed. An illustrative example for scalar StS USD reducible to differential is given. For future COF generalization, (i) methods of moments, quasi-moments, and one- and multidimensional densities of orthogonal expansions and (ii) development for stochastic inclusions are recommended. Keywords: regression linearization; stochastic system with unsolved derivatives (StS USD); stochastic process; conditionally optimal filtering (COF) PROBABILISTIC ANALYSIS OF A CLASS OF MARKOV JUMP PROCESSES
Abstract: The paper introduces a class of the jump processes. The first compound component represents aMarkov jump process with a finite state space. The second compound component jumps synchronously with the first one. Given the first component trajectory, the second component forms a sequence of independent random vectors. The corresponding conditional distributions are known and have intersecting support sets. This makes impossible the exact recovery of the first process component by the second one. The authors prove the Markov property for the considered class of random processes and obtain a collection of their probability characteristics. It includes the infinitesimal generator and its conjugate operator. Their knowledge makes possible the construction of the Kolmogorov equation system describing the evolution of the process probability distribution. Also, a martingale decomposition for an arbitrary function of the considered process was derived. It can be characterized by the solution to a system of linear stochastic differential equations with martingales on the right side. If the functions of the investigated process have finite moments of the second order, one may obtain the quadratic characteristics of martingales. Keywords: Markov jump process; infinitisemal generator; martingale decomposition; stochastic differential equation AUTONOMOUS LINEAR OUTPUT OF THE MARKOV CHAIN STABILIZATION BY SQUARE CRITERION ON AN INFINITE HORIZON
Abstract: The solution of the linear output of the stochastic differential system optimal control problem on an infinite horizon is adapted for one particular case of indirect observation. The ergodic Markov chain plays the role of a dynamic system and the autonomous linear output formed by it provides indirect noisy observations on the state of the chain. The control purpose is formulated as output stabilization in positions determined by the chain and periodically changing with chain state changes. The solution, as in a similar problem with complete information, is obtained as the limit form of optimal control in the corresponding problem with a finite horizon. Sufficient conditions for the control existence turn out to be typical conditions for linear-quadratic problems of structure of the optimal Wonham filter, only linear components are present in the control and all nonlinearity is limited by the equation of the filtering estimate. Due to this, the existence conditions include only the requirements for the autonomous Riccati equation solution. A numerical experiment for the mechanical drive model used in previous studies is discussed. The purpose of the experiment is to show the difference in the use of optimal control and its autonomous version. Keywords: Markov chain with continuous time; Wonham filter; linear differential system; optimal control; stabilization; square criterion TOWARDS A DEFINITION OF A BUSY PERIOD UNDER NONLOCAL DESCRIPTION OF INPUT FLOWS
Abstract: In course of a probabilistic modeling and analysis of complex controlled queueing systems with several conflicting input flows, in a series of papers, an approach was successfully applied, one of its features being a nonlocal description of various system building blocks. In this description, some information about true arrival and leave times of customers is lost. It leads to difficulties in defining a busy period but that is one of classic performance metrics for an operating queueing system. In this paper, a controlled queuing system busy period definition is based on selecting those observation instants when queues reach zero level. A cyclic service algorithm with fixed switching times as an example using a martingale technique and effective computational formulas are obtained for the mathematical expectation of busy periods related to individual queues. Keywords: controlled queueing system; nonlocal description of blocks; nonordinary Poisson flows; cyclic service algorithm; busy period; multivariate denumerable Markov chain; martingale; generalized Rouche. ’s theorem; Lagrange interpolation polynomial ANALYSIS OF NETWORK PERFORMANCE INDICATORS IN CASE OF NODE DAMAGE
Abstract: On the model of a multiuser communication system, changes in performance indicators are analyzed when network nodes are damaged. In the course of computational experiments, changes in the unit cost of resources and edge loading are monitored while simultaneously transmitting internodal flows in a damaged network. To assess the consequences of each damage, the obtained values are compared with the initial ones. For each damaged node, an increase in the unit cost of transmitting internodal flows is calculated. The number of source-sink pairs left without connection is determined. A set of guaranteed estimates of the maximum possible loads of network edges in case of any damage is formed. The average values for all damages are calculated. Summary diagrams for networks with various structural features are built on the basis of aggregated calculated indicators. Keywords: streaming model of the communication network; node damage assessment; edge loading CORRECT SUPERVISED CLASSIFICATION: JSM-METHOD OVER PRODUCT OF PARTIAL ORDERS
Abstract: The authors consider a logical approach to the supervised classification problem. A difference and a connection between two well-known directions of logical classification are noted: the direction represented by Correct Voting Procedures (CVP) and the direction based on the ideas of the JSM-method. The issues of improving the classifiers of the second direction are considered on the basis of using a less strict decisive rule and generalizing a scheme of work in the case when the featured descriptions of the objects under study are the elements of the Cartesian product of finite partially ordered sets. The developed new models of the JSM-classifiers use the ideas proposed earlier when creating similar algorithms for the CVP direction. The results of an experimental study on real-world tasks using a special linear ordering of feature values are presented. Keywords: supervised classification; logical classifier; Correct Voting Procedures; JSM-method; representative elementary classifier; partial order ASYMPTOTIC NORMALITY AND STRONG CONSISTENCY OF RISK ESTIMATE WHEN USING THE FDR THRESHOLD UNDER WEAK DEPENDENCE CONDITION
Abstract: An approach to solving the problem of noise removal in a large array of sparse data is considered based on the method of controlling the average proportion of false hypothesis rejections (False Discovery Rate, FDR). This approach is equivalent to threshold processing procedures that remove array components whose values do not exceed some specified threshold. The observations in the model are considered weakly dependent. To control the degree of dependence, restrictions on the strong mixing coefficient and the maximum correlation coefficient are used. The mean-square risk is used as a measure of the effectiveness of the considered approach. It is possible to calculate the risk value only on the test data; therefore, its statistical estimate is considered in the work and its properties are investigated. The asymptotic normality and strong consistency of the risk estimate are proved when using the FDR threshold under conditions of weak dependence in the data. Keywords: thresholding; multiple hypothesis testing; risk estimate NUMERICAL-ANALYTICAL SOLUTION OF THE DISCRETE-TIME TUNING PROBLEM FOR AN INTERVENTION MODEL IN THE FOREIGN EXCHANGE MARKET
Abstract: The work examines the problem of optimizing external influences (controls) on the process of changing the price of the so-called bi-currency basket on the foreign exchange market of the Russian Federation. The theoretical basis of the approach used is the solution of a stochastic tuning problem with discrete time. Based on the previous statistical analysis, it was established that the stochastic process characterizing the evolution of the bi-currency basket price, under certain conditions, can be quite adequately described by a classical homogeneous Markov chain. In this case, statistical estimates of the transition probabilities of the specified chain were obtained. Necessary auxiliary probabilistic characteristics of the Markov model are numerically determined. For various given cost characteristics, a study of the stationary cost indicator of management efficiency-average specific profit was conducted. Specific numerical solutions to the corresponding optimal control problem are obtained which can be interpreted as optimal external influences (interventions) on the stochastic process under study. Keywords: stochastic Markov and semi-Markov control models; discrete time tuning problem; fractional linear integral functionals on discrete probability distributions; optimal control in stochastic economic systems BASIC ARCHITECTURE OF REFLEXIVE-ACTIVE SYSTEMS OF ARTIFICIAL HETEROGENEOUS INTELLIGENT AGENTS
Abstract: The paper is devoted to the development of the basic architecture of reflexive-active systems of artificial heterogeneous intelligent agents including a standard functional structure of the system and a generalized architecture of agents. Due to the combination of heterogeneous agents in the system, it hybridizes various specialists’ knowledge and methods of formal representation of the systems taking into account the instrumental and functional heterogeneity of emerging problems. The reflexive capabilities of agents allow them to model other agents, themselves, and the system as a whole reducing the intensity of conflicts and the duration of building interaction when the composition of the system changes. As a result, self-organization of the system in a strong sense becomes possible during which for each new practical problem, a solution method relevant to it is developed. Keywords: reflection; reflexive-active system of artificial heterogeneous intelligent agents; hybrid intelligent multiagent system; team of specialists A MODEL FOR EXTRACTING KNOWLEDGE FROM PARALLEL TEXTS OF A LEXICOGRAPHIC INFORMATION SYSTEM
Abstract: The problem-oriented model of extracting linguistic knowledge from parallel texts is considered to be a key theoretical component for creating a lexicographic information system that provides integration of electronic bilingual dictionaries and parallel corpora. The proposed approach to solving the integration problem takes into account the emergence of new meanings of words and phrasemes which is due to the acquisition of new knowledge by experts who discover these meanings as a result of semantic analysis of regularly updated corpus data. The proposed model describes the human–computer interaction including the search for fragments of parallel texts as potential sources of new linguistic knowledge, its extracting by experts from texts, and representation in the lexicographic information system. The basis for building the problem-oriented model is the spiral model of knowledge generation which was proposed by Ikujiro Nonaka in 1991. The purpose of the paper is to describe the stages of building the model for discovering linguistic knowledge used in the lexicographic information system design. Keywords: lexicographic information system; parallel texts; spiral model of knowledge generation; problem-oriented model IMPLICIT LOGICAL-SEMANTIC RELATIONS IN PARALLEL TEXTS: ANNOTATION PRINCIPLES
Abstract: The problemof implicit logical-semantic relations (LSRs) annotation is considered. The state-of-the-art in the annotation of implicit LSRs is analyzed. The approaches focused on (i) analysis of the global discourse structure; (ii) analysis of the local discourse structure; and (iii) unification of the data annotated within different frameworks and development of a unified annotation standard are presented. The principles for annotating implicit LSRs in parallel texts are proposed, i. e., target of annotation is a translated correspondence (a pair of fragments from the original and translated texts). Translation correspondences illustrating implicit–explicit mismatch have been studied, i. e., where LSR markers are absent in the Russian text while in the text in another language, on the contrary, they are present. Taking into account the specificity of implicit LSRs, the following principles of their annotation were formulated: (i) it is necessary to determine the boundaries of LSR arguments (to ensure clarity and convenience of analysis); (ii) features of text blocks should form a hierarchical structure (to ensure convenience of using a large number of features); and (iii) if a feature of a text block has a lexical marker, this marker should be indicated (to ensure better justification of the annotator’s decisions). Keywords: linguistic annotation; discourse relations; logical-semantic relations; implicitness; parallel texts APPLYING COMPUTER-ASSISTED TOOLS TO LITERARY TRANSLATION: THE CASE OF PUNCTUATION
Abstract: The article highlights the opportunities that the integration of computer-assisted tools into the literary translator’s workbench provides in navigating the complexities of interlingual punctuation asymmetry. Across natural languages, punctuation principles can vary, which results in differences in the punctuation repertoire and its usage rules. For literary translators, understanding these differences is essential to accurately convey the artistic integrity of the source text. While interlingual punctuation asymmetry has long been studied,modern advancements in computer and language sciences, particularly, the corpus-based approach, offer new theoretical and practical insights that can greatly enhance the translation process. This approach allows for a deeper understanding of punctuation nuances leading to more informed translation choices and decisions. Thus, the article contributes to the recent trend of applying computer-assisted tools to literary translation. Keywords: computer-assisted literary translation; punctuation; asymmetry between languages; corpus-based translation studies; parallel corpus; English; French; Russian
|
 | |
 Phone of the Center: +7 (499) 135-62-60E-mail of the Center: ipiran@ipiran.ru | 
RUS
|