a priori uncertainty
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2021 ◽  
Vol 22 (8) ◽  
pp. 411-419
Author(s):  
V. B. Melekhin ◽  
M. V. Khachumov

The expediency of using the tools of visual-effective, visual-figurative and conceptual thinking for planning the purposeful activity of autonomous intelligent agents in problem environments of various degrees of a priori uncertainty has been substantiated. The content is revealed and the role of each form of thinking is shown in the process of automatic planning of the purposeful behavior of autonomous intelligent agents in the changing conditions of functioning. The special role of conceptual thinking in the performance of complex tasks by autonomous agents and the planning of polyphasic behavior associated with it is indicated. Taking into account the complexity of the problems associated with the formalization of mental acts of conceptual thinking, possible ways of its gradual development from the initial level to the transition to higher levels of development are shown, expanding on this basis the class of tasks solved by autonomous intelligent agents. A model of knowledge representation and tools for deriving solutions of the initial level of conceptual thinking have been developed, which allow intelligent agents to break down the tasks they receive into sub-goals of behavior. Then, on this basis, plan polyphase activity by searching for solutions to the associated subtasks, which ensure the determination of the minimum length routes of movement in a prob lematic environment with obstacles and the purposeful manipulation of objects in it. The tools are synthesized allowing to establish the order of elaboration of complex actions included in the structure of the task formulated by autonomous intelligent agents. It is shown that the further development of the proposed methodological foundations for constructing intelligent problem sol vers is associated with the formalization of a higher level of mental acts of conceptual thinking, which make it possible to solve practical problems of different complexity, formulated both in procedural and declarative form of presentation in the form of various target situations of the problem environment, having a large dimension.


Author(s):  
Dmitriy Demin ◽  
Oleh Domin

The object of research is the process of oxide reduction in a reaction system of mass m due to the reaction on a contact surface with an area of S. An adaptive technology is proposed that allows one to construct the kinetic equation of the process in which the oxide is reduced from the initial product under conditions of a priori uncertainty. A priori uncertainty regarding the behavior of a physicochemical system is understood as the fact that the following information is not available to the researcher: – about the change in the mass of the reaction system and the area of the contact surface; – about the rate of accumulation of the finished product; – about the time of withdrawal of the finished product from the system. The proposed adaptive technology includes five sequential stages to eliminate a priori uncertainty. This is ensured through the use of an adaptive algorithm, which allows obtaining the maximum accuracy in estimating the output variable by selecting the optimal parameter of the adaptive algorithm, and the subsequent canonical transformation. The introduced concept "canonical transformation of the kinetic equation" has the following meaning: having received some adequate description of the kinetic equation in a Cartesian coordinate system, a transformation is carried out that allow representing the equation in a new Cartesian coordinate system in such a way that its structure corresponds to the canonical form. The basic postulate of chemical kinetics can be such a canonical type.


2021 ◽  
Vol 3 (9(111)) ◽  
pp. 6-15
Author(s):  
Mykola Kaliuzhnyi

The radio monitoring of radiation and interference with electronic means is characterized by the issue related to the structural-parametric a priori uncertainty about the type and parameters of the ensemble of signals by radio-emitting sources. Given this, it is a relevant task to devise a technique for the mathematical notation of signals in order to implement their processing, overcoming their a priori uncertainty in terms of form and parameters. A given problem has been solved by the method of generalization and proof for the finite signals of the Whittaker-Kotelnikov-Shannon sampling theorem (WKS) in the frequency-time domain. The result of proving it is a new discrete frequency-temporal description of an arbitrary finite signal in the form of expansion into a double series on the orthogonal functions such as sinx/x, or rectangular Woodward strobe functions, with an explicit form of the phase-frequency-temporal modulation function. The properties of the sampling theorem in the frequency-time domain have been substantiated. These properties establish that the basis of the frequency-time representation is orthogonal, the accuracy of approximation by the basic functions sinx/x and rectangular Woodward strobe functions are the same, and correspond to the accuracy of the UCS theorem approximation, while the number of reference points of an arbitrary, limited in the width of the spectrum and duration, signal, now taken by frequency and time, is determined by the signal base. The devised description of signals in the frequency-time domain has been experimentally investigated using the detection-recovery of continuous, simple pulse, and linear-frequency-modulated (LFM) radio signals. The constructive nature of the resulting description has been confirmed, which is important and useful when devising methods, procedures, and algorithms for processing signals under the conditions of structural-parametric a priori uncertainty.


Author(s):  
О. М. Romanov ◽  
V. Yu. Kotiubin

Context. To improve the noise immunity of communication and data transmission systems, error-correcting coding is widely used. The most common because of their effectiveness are block coding methods. Under conditions of partial a priori uncertainty of the type and parameters of encoding, before decoding the digital sequence, a preliminary analysis is carried out to determine them. In block coding, to determine the period of a digital sequence caused by the addition of a sync sequence to it, and which can determine the type and parameters of coding, a common approach is to use their correlation properties. Objective. The object of the research is the presentation of periodicity search algorithms in digital sequences with block errorcorrecting coding under conditions of partial a priori uncertainty of the type and parameters of the error-correcting code. Method. The article presents two periodicity search algorithms in digital sequences with block coding and describes the principle of their operation. The basis of one algorithm is the calculation of the autocorrelation function, the basis of the other is calculation of the cross-correlation function. It is shown that the length of the digital sequence should be twice as long as the maximum possible period. The operation of both algorithms is illustrated by examples. Results. Based on the proposed algorithms, special software has been developed. The results of determining the period of digital sequences with block error-correcting coding at different values of the period confirmed the efficiency of the proposed algorithms. Both proposed algorithms give approximately the same result. Experimental dependences of the calculation time of auto- and crosscorrelation functions from the length of the digital sequence and the maximum possible period are established. The period search algorithm in a digital sequence, that use the cross-correlation function of its components, is more efficient due to fewer calculations. Conclusions. For the first time, two periodicity search algorithms in digital sequences with block error-correcting based on the determination of their correlation functions are obtained. The application of the developed algorithms in practice allows, under partial a priori uncertainty of the type and parameters of the error-correcting code, to determine the period of digital sequences in real time even at large values of the period, and based on it, to identify the type and parameters of block error-correcting codes.


2021 ◽  
Vol 2 (28) ◽  
pp. 9-14
Author(s):  
I. V. Svetlov ◽  
◽  
Yu. P. Ivanov ◽  

The method of optimal characteristics, high stability and simplicity of the algorithm is presented. The method under consideration is compared with Kalman filtering. Cases of a priori uncertainty with unknown correlation functions of the noise and the useful signal are considered. Key words: finite-time filtering, Kalman filtering, a priori uncertainty.


Author(s):  
Zhang Liqiang ◽  
Cao Weiling ◽  
Viacheslav Davydov ◽  
Veronika Brechko

In dynamic models, threats (vulnerabilities) can be viewed as a flow of temporary events. If the intervals of realized cyber threats are recorded, then a continuous log-list of events related to software security can be formed. In some cases and models, only the number of realized cyber threats for an arbitrary time interval can be recorded. In this case, the software response to threats can be represented only at discrete points. In static models, the implementation of cyber threats is not related to time, but the dependence of the number of errors or the number of implemented test cases (models by error area) on the characteristics of the input data (models by data area) is taken into account. The article analyzes the methods of mathematical formalization of the software penetration testing process. This software testing method is one of many approaches to testing the security of computer systems. The article substantiates the importance of the processes of preliminary prototyping and mathematical formalization. The classification is carried out and the advantages and disadvantages of the main approaches of mathematical modeling are highlighted. The list and main characteristics of dynamic and static models are presented. One of the negative factors of formalization is indicated - the neglect of the factors of a priori uncertainty in the safety parameters in static models.


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