Viktor Pavliska - Academia.edu (original) (raw)

Papers by Viktor Pavliska

Research paper thumbnail of Generalized Peterson’s Rules in Fuzzy Natural Logic

Atlantis studies in uncertainty modelling, 2021

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Research paper thumbnail of Representation of Fuzzy IF-THEN rules by Petri Nets

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Research paper thumbnail of A linguistic approach to time series modeling with the help of F-transform

Fuzzy Sets and Systems, Oct 1, 2011

In this paper, we describe an approach to modeling and forecasting time series that uses the theo... more In this paper, we describe an approach to modeling and forecasting time series that uses the theory of evaluative linguistic expressions, fuzzy/linguistic IF–THEN rules and the fuzzy transform method. We show that the use of a linguistic approach allows better readability and understandability without any significant deterioration in precision.

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Research paper thumbnail of Sugeno Integral Extended to Undefined Inputs

Springer eBooks, 2022

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Research paper thumbnail of Parallel mining of fuzzy association rules on dense data sets

The aim of this paper is to present a scalable parallel algorithm for fuzzy association rules min... more The aim of this paper is to present a scalable parallel algorithm for fuzzy association rules mining that is suitable for dense data sets. Unlike most of other approaches, we have based the algorithm on the Webb's OPUS search algorithm [1]. Having adopted the master/slave architecture, we propose a simple recursion threshold technique to allow load-balancing for high scalability.

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Research paper thumbnail of On Missing Membership Degrees: Modelling Non-existence, Ignorance and Inconsistency

Advances in intelligent systems and computing, Jul 25, 2018

In real-world applications, mathematical models must often deal with values that are missing or u... more In real-world applications, mathematical models must often deal with values that are missing or undefined. The aim of this paper is to provide a survey on types and reasons for such non-availability. It motivates the need to handle different reasons for missingness in a different, but appropriate way. In particular, non-existence, ignorance, and inconsistency are studied. The paper also presents a novel way of how to compute with different types of missing values at the same time.

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Research paper thumbnail of Error Optimization of Fuzzy Transform Using Evolution Algorithms

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Research paper thumbnail of Time Series: How Unusual Local Behavior Can Be Recognized Using Fuzzy Modeling Methods

Studies in computational intelligence, Jun 19, 2020

In this paper, we address the problem of automatic recognition of structural breaks in time serie... more In this paper, we address the problem of automatic recognition of structural breaks in time series. The former are unexpected shifts of the course or sudden change of the volatility of time series. Structural breaks can be caused, e.g., by changes in the organization of a company, global or local economic development, global shifts in capital and labor, various kinds of outer influences such as discovery or depletion of natural resources, etc. Structural breaks in time series are usually detected using statistical methods. In this paper, we suggest using special non-statistical techniques of fuzzy modeling. We will employ two classes of them, namely the fuzzy transform (F-transform) and selected methods of Fuzzy Natural Logic (FNL). The fuzzy transform enables us to estimate the average slope of time series in an area characterized by a fuzzy set. The slope is then evaluated by evaluative linguistic expressions, which enables us to identify intervals with monotonous behavior and, consequently, identify structural breaks. Our method is simple, transparent, and computationally effective.

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Research paper thumbnail of Computation of Support and Confidence for Interval-Valued Fuzzy Association Rules

International Journal of Computational Intelligence Systems, 2020

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Research paper thumbnail of Analysis and prediction of time series using fuzzy transform

... It Address: University of Ostrava, Institute for Research and Applica-tions of Fuzzy Modellin... more ... It Address: University of Ostrava, Institute for Research and Applica-tions of Fuzzy Modelling, 30. dubna 22, 70103 Ostrava, Czech republic (email: {Irina.Perfilieva,Vilem.Novak, Viktor.Pavliska, Antonin.Dvorak, Martin.Stepnicka}@osu.cz). ...

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Research paper thumbnail of Linguistic approach to time series analysis and forecasts

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Research paper thumbnail of Specialized software for fuzzy natural logic and fuzzy transform applications

In this paper, three special soft computing software systems are presented. The systems are based... more In this paper, three special soft computing software systems are presented. The systems are based on the original results in two areas: fuzzy natural logic and fuzzy transform. The first software is LFL Controller that is a universal SW system that can be used in fuzzy or linguistic control, and in decision-making. The system implements results of fuzzy natural logic, namely the theory of evaluative linguistic expressions and perception-based logical deduction. This means the control or decision strategy are defined directly in natural language. Additionally, it can also realize classical fuzzy control on the basis of relational interpretation of fuzzy IF-THEN rules. This system has wide range of applications and was already applied in control of real plants. The second system is LFL Forecaster that is a specialized SW for analysis and forecasting of time series. The analysis is realized using F-transform and forecasting using results of fuzzy natural logic. The third system is FT-Studio that is a specialized SW for computation of fuzzy transform of functions that can be defined either using a formula, or given by data.

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Research paper thumbnail of Association Analysis on Interval-Valued Fuzzy Sets

Lecture Notes in Computer Science, 2018

The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy... more The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy sets. Interval-valued fuzzy sets allow for intervals of membership degrees to be assigned to each element of the universe. These intervals may be interpreted as partial information where the exact membership degree is not known. The paper provides a generalized definition of support and confidence, which are the most commonly known measures of quality of a rule.

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Research paper thumbnail of Undefined Values in Fuzzy Logic

Advances in intelligent systems and computing, Aug 30, 2017

The main objective of this paper is to propose an extended algebra of truth values by special tru... more The main objective of this paper is to propose an extended algebra of truth values by special truth values which may have several interpretations, such as “undefined”, “non-applicative” “overdetermined”, “undetermined”, etc. In this paper, we will analyze several situations, where the non-existent data may come from, and show within a fuzzy sets framework that different cases of non-existence have to be carefully treated and interpreted in a different way.

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Research paper thumbnail of An Algorithm for Intermediate Quantifiers and the Graded Square of Opposition Towards Linguistic Description of Data

Advances in intelligent systems and computing, Aug 30, 2017

The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA m... more The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA method for a linguistic characterization of relationships in data. Namely, we utilize the theory of intermediate quantifiers, which provides mathematical interpretation of natural language expressions describing quantity such as “Almost all”, “Few” etc., to describe relationships in data using vague terms that are natural in human expression. We provide an algorithm for computation of truth degrees of expressions containing such quantifiers. Moreover, we discuss some basic properties of intermediate quantifiers (contraries, contradictories, sub-contraries and sub-alterns), which formulate the graded Peterson’s square of opposition, and which can be used to infer new expressions from existing ones.

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Research paper thumbnail of Advanced Image Compression on the Basis of Fuzzy Transforms

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Research paper thumbnail of Peterson’s Rules Based on Grades for Fuzzy Logical Syllogisms

Lecture notes in networks and systems, 2023

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Research paper thumbnail of LFL Forecaster: Analysis, Forecasting and Mining Information from Time Series

In this paper, we describe the software LFL Forecaster for analysis, forecasting and mining infor... more In this paper, we describe the software LFL Forecaster for analysis, forecasting and mining information from time series using special methods of fuzzy modeling. The main theoretical tools are fuzzy transform and methods of fuzzy natural logic. The software also provides information in sentences of natural language mined from time series. We demonstrate functioning of the software on several real time series from the area of economy and other sectors.

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Research paper thumbnail of An Algorithm for Intermediate Quantifiers and the Graded Square of Opposition Towards Linguistic Description of Data

The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA m... more The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA method for a linguistic characterization of relationships in data. Namely, we utilize the theory of intermediate quantifiers, which provides mathematical interpretation of natural language expressions describing quantity such as “Almost all”, “Few” etc., to describe relationships in data using vague terms that are natural in human expression. We provide an algorithm for computation of truth degrees of expressions containing such quantifiers. Moreover, we discuss some basic properties of intermediate quantifiers (contraries, contradictories, sub-contraries and sub-alterns), which formulate the graded Peterson’s square of opposition, and which can be used to infer new expressions from existing ones.

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Research paper thumbnail of Association Analysis on Interval-Valued Fuzzy Sets

The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy... more The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy sets. Interval-valued fuzzy sets allow for intervals of membership degrees to be assigned to each element of the universe. These intervals may be interpreted as partial information where the exact membership degree is not known. The paper provides a generalized definition of support and confidence, which are the most commonly known measures of quality of a rule.

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Research paper thumbnail of Generalized Peterson’s Rules in Fuzzy Natural Logic

Atlantis studies in uncertainty modelling, 2021

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Research paper thumbnail of Representation of Fuzzy IF-THEN rules by Petri Nets

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A linguistic approach to time series modeling with the help of F-transform

Fuzzy Sets and Systems, Oct 1, 2011

In this paper, we describe an approach to modeling and forecasting time series that uses the theo... more In this paper, we describe an approach to modeling and forecasting time series that uses the theory of evaluative linguistic expressions, fuzzy/linguistic IF–THEN rules and the fuzzy transform method. We show that the use of a linguistic approach allows better readability and understandability without any significant deterioration in precision.

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Research paper thumbnail of Sugeno Integral Extended to Undefined Inputs

Springer eBooks, 2022

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Research paper thumbnail of Parallel mining of fuzzy association rules on dense data sets

The aim of this paper is to present a scalable parallel algorithm for fuzzy association rules min... more The aim of this paper is to present a scalable parallel algorithm for fuzzy association rules mining that is suitable for dense data sets. Unlike most of other approaches, we have based the algorithm on the Webb's OPUS search algorithm [1]. Having adopted the master/slave architecture, we propose a simple recursion threshold technique to allow load-balancing for high scalability.

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Research paper thumbnail of On Missing Membership Degrees: Modelling Non-existence, Ignorance and Inconsistency

Advances in intelligent systems and computing, Jul 25, 2018

In real-world applications, mathematical models must often deal with values that are missing or u... more In real-world applications, mathematical models must often deal with values that are missing or undefined. The aim of this paper is to provide a survey on types and reasons for such non-availability. It motivates the need to handle different reasons for missingness in a different, but appropriate way. In particular, non-existence, ignorance, and inconsistency are studied. The paper also presents a novel way of how to compute with different types of missing values at the same time.

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Research paper thumbnail of Error Optimization of Fuzzy Transform Using Evolution Algorithms

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Time Series: How Unusual Local Behavior Can Be Recognized Using Fuzzy Modeling Methods

Studies in computational intelligence, Jun 19, 2020

In this paper, we address the problem of automatic recognition of structural breaks in time serie... more In this paper, we address the problem of automatic recognition of structural breaks in time series. The former are unexpected shifts of the course or sudden change of the volatility of time series. Structural breaks can be caused, e.g., by changes in the organization of a company, global or local economic development, global shifts in capital and labor, various kinds of outer influences such as discovery or depletion of natural resources, etc. Structural breaks in time series are usually detected using statistical methods. In this paper, we suggest using special non-statistical techniques of fuzzy modeling. We will employ two classes of them, namely the fuzzy transform (F-transform) and selected methods of Fuzzy Natural Logic (FNL). The fuzzy transform enables us to estimate the average slope of time series in an area characterized by a fuzzy set. The slope is then evaluated by evaluative linguistic expressions, which enables us to identify intervals with monotonous behavior and, consequently, identify structural breaks. Our method is simple, transparent, and computationally effective.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Computation of Support and Confidence for Interval-Valued Fuzzy Association Rules

International Journal of Computational Intelligence Systems, 2020

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Research paper thumbnail of Analysis and prediction of time series using fuzzy transform

... It Address: University of Ostrava, Institute for Research and Applica-tions of Fuzzy Modellin... more ... It Address: University of Ostrava, Institute for Research and Applica-tions of Fuzzy Modelling, 30. dubna 22, 70103 Ostrava, Czech republic (email: {Irina.Perfilieva,Vilem.Novak, Viktor.Pavliska, Antonin.Dvorak, Martin.Stepnicka}@osu.cz). ...

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Research paper thumbnail of Linguistic approach to time series analysis and forecasts

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Specialized software for fuzzy natural logic and fuzzy transform applications

In this paper, three special soft computing software systems are presented. The systems are based... more In this paper, three special soft computing software systems are presented. The systems are based on the original results in two areas: fuzzy natural logic and fuzzy transform. The first software is LFL Controller that is a universal SW system that can be used in fuzzy or linguistic control, and in decision-making. The system implements results of fuzzy natural logic, namely the theory of evaluative linguistic expressions and perception-based logical deduction. This means the control or decision strategy are defined directly in natural language. Additionally, it can also realize classical fuzzy control on the basis of relational interpretation of fuzzy IF-THEN rules. This system has wide range of applications and was already applied in control of real plants. The second system is LFL Forecaster that is a specialized SW for analysis and forecasting of time series. The analysis is realized using F-transform and forecasting using results of fuzzy natural logic. The third system is FT-Studio that is a specialized SW for computation of fuzzy transform of functions that can be defined either using a formula, or given by data.

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Research paper thumbnail of Association Analysis on Interval-Valued Fuzzy Sets

Lecture Notes in Computer Science, 2018

The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy... more The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy sets. Interval-valued fuzzy sets allow for intervals of membership degrees to be assigned to each element of the universe. These intervals may be interpreted as partial information where the exact membership degree is not known. The paper provides a generalized definition of support and confidence, which are the most commonly known measures of quality of a rule.

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Research paper thumbnail of Undefined Values in Fuzzy Logic

Advances in intelligent systems and computing, Aug 30, 2017

The main objective of this paper is to propose an extended algebra of truth values by special tru... more The main objective of this paper is to propose an extended algebra of truth values by special truth values which may have several interpretations, such as “undefined”, “non-applicative” “overdetermined”, “undetermined”, etc. In this paper, we will analyze several situations, where the non-existent data may come from, and show within a fuzzy sets framework that different cases of non-existence have to be carefully treated and interpreted in a different way.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of An Algorithm for Intermediate Quantifiers and the Graded Square of Opposition Towards Linguistic Description of Data

Advances in intelligent systems and computing, Aug 30, 2017

The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA m... more The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA method for a linguistic characterization of relationships in data. Namely, we utilize the theory of intermediate quantifiers, which provides mathematical interpretation of natural language expressions describing quantity such as “Almost all”, “Few” etc., to describe relationships in data using vague terms that are natural in human expression. We provide an algorithm for computation of truth degrees of expressions containing such quantifiers. Moreover, we discuss some basic properties of intermediate quantifiers (contraries, contradictories, sub-contraries and sub-alterns), which formulate the graded Peterson’s square of opposition, and which can be used to infer new expressions from existing ones.

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Research paper thumbnail of Advanced Image Compression on the Basis of Fuzzy Transforms

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Peterson’s Rules Based on Grades for Fuzzy Logical Syllogisms

Lecture notes in networks and systems, 2023

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Research paper thumbnail of LFL Forecaster: Analysis, Forecasting and Mining Information from Time Series

In this paper, we describe the software LFL Forecaster for analysis, forecasting and mining infor... more In this paper, we describe the software LFL Forecaster for analysis, forecasting and mining information from time series using special methods of fuzzy modeling. The main theoretical tools are fuzzy transform and methods of fuzzy natural logic. The software also provides information in sentences of natural language mined from time series. We demonstrate functioning of the software on several real time series from the area of economy and other sectors.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of An Algorithm for Intermediate Quantifiers and the Graded Square of Opposition Towards Linguistic Description of Data

The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA m... more The aim of this paper is to apply main theories of fuzzy natural logic together with fuzzy GUHA method for a linguistic characterization of relationships in data. Namely, we utilize the theory of intermediate quantifiers, which provides mathematical interpretation of natural language expressions describing quantity such as “Almost all”, “Few” etc., to describe relationships in data using vague terms that are natural in human expression. We provide an algorithm for computation of truth degrees of expressions containing such quantifiers. Moreover, we discuss some basic properties of intermediate quantifiers (contraries, contradictories, sub-contraries and sub-alterns), which formulate the graded Peterson’s square of opposition, and which can be used to infer new expressions from existing ones.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Association Analysis on Interval-Valued Fuzzy Sets

The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy... more The aim of this paper is to generalize the concept of association rules for interval-valued fuzzy sets. Interval-valued fuzzy sets allow for intervals of membership degrees to be assigned to each element of the universe. These intervals may be interpreted as partial information where the exact membership degree is not known. The paper provides a generalized definition of support and confidence, which are the most commonly known measures of quality of a rule.

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