# Vassil Sgurev's research while affiliated with Bulgarian Academy of Sciences and other places

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## Publications (48)

This work is dedicated to the history of emergence and the development of the research in the field of Artificial Intelligence (AI) in Bulgaria until the end of the past century. It is pointed out that first research activities are in the Bulgarian Academy of Sciences (BAS)—Institute of mathematics, and a little later in the Institute of technical...

At the end of 1978 in the Bulgarian Academy of Sciences (BAS) a state project was realized to create a powerful enough institute with an Experimental Base in the field of high technologies and in particular in robotics and also in computer cybernetics control systems. Not a big research group in this institute led by the experienced researcher, con...

Technical sciences come and develop in BAS relevantly late: at the end of the nineteenth century and at the beginning of the twentieth century. Then for BAS members are elected the first representatives of these sciences. Only just in 1959 a state act forms the Department of Technical Sciences (DTS) as a self-dependent structural division within th...

The present work describes the significant achievements of this institute, and of BAS in general in research, development, testing, production, elaboration of operative documentation, and direct – without intermediaries – implementation of robots and control devices to them in serial production in two plants in Stara Zagora – the National and Indus...

An imaginary logic, i-logic was introduced for solving of some unsolvable problems in the framework of the classical propositional logic. On the other hand similar unsolvable problems arise in the imaginary logic itself. Introduction of a second imaginary j-logic is suggested in the present work through which this insolvability in the i-logic is su...

Several network flow models are considered in the present work for transportation of resources—material, financial, communication, commodities, services etc. and the risks related to them at transportation on the network the goal being to achieve maximal flow of minimal risk and minimal payment for the risk, e.g. minimal insurance cost. Five models...

Imaginary propositional logic (i-logic) is being introduced through which the classical propositional logic (called in the present work real or r-logic) is extended to complex, summary (s-logic), in which the two logics above are interpreted. For this purpose a constraint (axiom) is added to the structures of the two logics—r and i, which connects...

This paper concerns implementing some methods designed for computation of various mathematical constants with high precision in specific environment, namely .NET Framework. The work is part of a series tracing the progress of creating tools for high precision computations in this environment and may be considered as continuation, in this direction,...

Complex sets are investigated in this work in which besides the classical Cantor’s sets imaginary ones are also introduced. This provides possibility equations on sets to be solved that have no solution in the framework of the classical set theory. Each element of the complex set is assumed to be in only one state of the possible two states: real,...

A new network flow method is proposed in this work for optimal distribution of risk between the different sections (arcs) of the network. It is supposed at that that the maximum admissible risks on the arcs are known in advance. This provides a possibility these values to be considered as arc capacities and the risk itself as a network flow. Such a...

The present work proposes an initiation of imaginary sets, which by an additional axiom are connected with the classical Cantor’s sets and in this way new complex sets are formed. These complex sets provide a possibility some set equations to be solved for which no solution exists in the classical Cantor’s set theory. In such an approach one and th...

Methods for calculating the max network flow with min cut and a flow of min cost, considering the risk on the separate sections of the network, are proposed in this work. The capacity of each arc is so defined, that it does not exceeds ‘the physical’ arc constraints as well as the admissible risk of the arc network flow function. The maximal flow o...

The complex s-logic is being elaborated as an extension of the classical propositional logic (called r-logic) by introducing an additional imaginary logic (i-logic). Both logics -r and i are connected by an additional requirement (an axiom). This provides a possibility for solving unsolvable up to now logical equations. All three logics - r, i, and...

This two volume set of books constitutes the proceedings of the 2014 7th IEEE International Conference Intelligent Systems (IS), or IEEE IS’2014 for short, held on September 24‐26, 2014 in Warsaw, Poland. Moreover, it contains some selected papers from the collocated IWIFSGN'2014-Thirteenth International Workshop on Intuitionistic Fuzzy Sets and Ge...

The innovation introduction, no matter whether a product, technology, a method, etc., is being implemented, is connected with considerable risk of investments loss and highly stochastic behaviour, depending on unpredictable factors. It is acknowledged that the innovation passes at least through 6 general stages: 1 - Prestart stage; 2 - Start stage;...

An approach is proposed in which the classical logic (called real logic) is extended to complex propositional logic, which due to the concrete constraints will be named Summary logic (S-logic). It is shown that by the S-logic classes of problems may be solved which are inaccessible for the real logic. It is shown that the S-logic logical variables...

In this paper we consider a binary Markov process, i.e. one that has two states and the prevailing probability of being in one them. This is used for interpretation of the propositional logic through a binary Markov process which allows putting in correspondence the prevailing probability of the Markov process for falling in the state True or False...

Recent industry requires efficient fault discovering and isolation solutions in process equipment service. This problem is a real-world problem of typically ill-defined systems, hard to model, with large-scale solution spaces. Design of precise models is impractical, too expensive, or often non-existent. Support service of equipment requires genera...

The innovation processes are connected with uncertainty and considerable financial risk. No matter whether a new product, technology or methodology is promoted, there are several stages that the innovation passes. The first three are connected with venture investments and the final - with eventual good profits. It is possible that the outcome is a...

In decision making logic it is often necessary to solve logical equations for which, due to the features of disjunction and conjunction, no admissible solutions exist. In this paper an approach is suggested, in which by the introduction of Imaginary Logical Variables (ILV), the classical propositional logic is extended to a complex one. This provid...

In the decision making logic it is often necessary solving of logical equations for which, due to the features of disjunction and conjunction, no admissible solutions exist. An approach is suggested in which by introducing of Imaginary Logical Variables (ILV) the classical propositional logic is extended to a complex one. This provides a possibilit...

Below are a number of specific weaknesses inherent to contemporary ATM devices including the ones with biometric checks or with other advanced applications. Reasons are considered that lead to applications of intelligent, logic-based methods aiming at reduction of risk factors to ATMs. Special attention is paid to applications of Puzzle method in A...

The paper presents a research on transitive probabilities of a binary Markov logic. Analytical dependencies are obtained of such transitions. A Markov interpretation is introduced of propositional-logic formulas using only two binary Markov matrices, two rules and a suitably selected negation of binary vectors. Formulas are obtained for final trans...

Network flow interpretation of the transportation unloading processes in industrial transport oriented towards real time computer control is proposed. Requirements for minimization of the total run of the transportation units are set, as well as for averaging within predefined limits of the useful content in the product transported. An exact networ...

Some research papers discussing methodology, problems, realizations, and trends in intelligent data processing, are presented. Visual novelty detection and tracking systems are considered in the paper 'An approach to automatic real-time novelty detection, object identification, and tracking in video streams based on recursive density estimation and...

A method for revealing and resolving conflicts is presented, especially well applicable for resolution of contradictions. It is shown that agents receive a greater autonomy via a correctly directed or selectable identification and conflict resolution inside the accumulated knowledge. The advantages of the introduced method are presented compared to...

A stochastic interpretation of propositional logic formulas is introduced that uses a specific discrete Markov process with two states. The requirements for this interpretation are formulated. It is shown that the obtained from it stochastic distributions are compatible on a qualitative (probabilistic) level with the respective results of the propo...

An intelligent multicascade control system is proposed using hybrid multi-agent and ontology framework. Fuzzy logic based extension of conventional ontology is implemented to meet uncertainties in the plant, its environment and sensor information. Ant colony optimization is applied to realize trade-off between requirements and control resources as...

Contemporary knowledge discovery systems are mainly quantitative. This part of the research could be successfully combined with the considered qualitative research in acquisition, elicitation, and discovery of logic-based rules and patterns. The paper introduces a synthetic metamethod (SMM), which is aimed to support different types of creative pro...

This paper presents two new approaches for use in complete process monitoring. The first concerns the identification of nonlinear principal component models. This involves the application of linear principal component analysis (PCA), prior to the identification ...

Generalized approach for non-square plants (NSP) control based on multi agent system (MAS) is proposed. The control system provides relevant reconfiguration and adaptation in case of plant changes, due to manipulated variables (MV) saturation, filature of input and/or output instrumentation, close proximity to ill-conditioning. A big flexibility is...

The study of the research carried out on methodologies and applications in contemporary intelligent systems is described. There are various methods related to the multimeasurement tool for decision making related to intuitionistic fuzzy sets (IFS). Operations, relations, and level operators were defined according to the fuzzy sets. IFS are suitable...

The paper introduces the method of parallel elaboration of intelligent agents (IAS) as layers of functional units (FUs) which are recursive on all levels (FUs, layers of FUs, IAs). A refined technique of this method are the coordinatewise approaches (coordinatewise analysis, coordinatewise optimization, etc.) The technique of coordinatewise analysi...

The paper introduces a synthetic metamethod SMM which is aimed at automation of fuzzy perceptions approval. Also the considered methods are applicable in creative processes concerning different types of intelligent systems. The metamethod is based on an analysis of incoming perception-oriented knowledge and a successive check in the domain. The pro...

New adaptive search methods based on multiresolution analysis and wavelet theory are introduced and discussed within the framework of the Markov theory. These stochastic search methods are suited to problems for which good solutions tend to cluster within ...

The First International IEEE Symposium on Intelligent Systems (IS ′02), held 10-12 September 2002 in Varna, Bulgaria, was intended to give scientists and engineers the opportunity to present their new research achievements and applications and to discuss the current status and future trends in the area of intelligent systems. In addition to the mai...

An approach concerning the applications of three-valued logics to knowledge-based systems is considered in the paper. The incompleteness of the scope is an existing fact, which leads in practice to the appearance of many difficulties and obstacles. One of the conclusions is that different probabilistic approaches could enlarge the problems instead...

An approach is proposed for resolving the inconsistencies in the knowledge base of a knowledge based system (KBS). The considered process consists of two stages: detection of inconsistent facts, and automatic estimation of their plausibility. The second stage has been used for resolving the contradiction if the processing is automatic. In interacti...

The state of the Bulgarian information society and its place among such societies of other countries is determined based on internationally accepted parameters: technical certainty indicator, indicator for transparency of communications and index of the information society determining the state of the information society. The basic statistical data...

Possibilities for implementation of intelligent agents as distributed systems in softsensing applications are introduced. The research includes different options with suitable neural networks serving as bases for intelligent agents of different types. The investigation in the paper is oriented towards solutions of highly sophisticated softsensing p...

The paper examines peculiarities of the development of logical and ontological structures, their mutual relations and interdependencies. Basic trends in the development of contemporary logical and ontological structures are analyzed.

## Citations

... The main results achieved according to the literature [1][2][3][4][5][6] can be summarized as follows: ...

... The use of logical structures in continuous space can solve this problem, but much larger computing resources are required. Complex hierarchical logic [4] is a formalism through which a decision can be made by creating a hierarchy based on the reliability of the values of each IoT. The complex hierarchical logic of the proposition, denoted as complex HS-logic, combines two real-logic Lr with two states True and False and imaginary logic Li with two other states {i, ¬i }, which are not equivalent to {T, F}. ...

... On the other hand, in the movement of vehicles and loading and unloading operations there are various risks, the cost of which must be taken into account in the optimization of management processes. Similarly, in both natural disasters and man-made events, the risk is usually considered as a product of two measures -the amount of transported product (resource) between the start and end points of a section and the probability of an adverse event when crossing that section [2,3]. ...

... For the mentioned golden ratio (GR), moon age (MA), lunar month (LM), Euler-Mascheroni constant (EM), Embree-Frefethen constant (EF), Landau-Ramanujan constant (LR), prime quadruplet (PQ) and, etc., using MATLAB to conduct simulations, and the results are shown from Table 3 to Table 9 (Zhang et al., 2015;Chen, 2016;Dzhambov and Sgurev, 2016). Table 3 The results of the conventional algorithm and the GR algorithm based on Kn = 0.618 Define the connectedness of L as the number of every node's mean adjacent nodes. ...

... In processes of selection and ranking, the GDM could be applied to find a solution a single alternative or set alternatives according to the preferences provided by the authorized group of experts. While the most publications considered the problem for handle different expressions of experts' preferences by utility-based individual preferences [23], fuzzy relations [24,25], decision Markov logic [26], fuzzy logic based on multi-criteria evaluation [27], multidimensional preference [28], linguistic information [29], etc., the current paper emphasizes on the evaluation and aggregation phase of the group decision-making process. ...

... "Opposition is concerned with the relationship between entities, objects or their abstractions of the same nature which are completely different in some manner" [2]. For example, hot and cold are description of temperature (same kind) but completely different. ...

Reference: Opposition based computing - A survey

... In [3] it was shown that the difficulties in solving a certain class of logical equations within judgmental logic can be significantly reduced by introducing an auxiliary logical structure called imaginary logic, which also obeys the axioms of Boolean algebra. ...

... Then the risk is defined as a product of the measures described above. In [1] the case was considered when risk is evaluated and controlled on a network in which some resources (raw materials, money flows etc.) are being transported aiming at that to minimize the transportation expenses observing some limits of the risk. The transportation resource is considered in [1] as a network flow and the risk is in given boundaries – constraints related to the capacities of the separate sections (arcs). ...

... In [82], the studies on information packets and queuing delays considering unidirectional topologies is mentioned. In [99], the importance of unidirectional process while managing risks and uncertainty in financial sector is discussed. In addition, these days the term unidirectional data flow is used while developing applications related to Android, and data flow between view, presenter and model is discussed as unidirectional. ...