Igor Gaibei

Mr. Igor Gaibei

University of Silesia, Katowice, Śląskie, Poland

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 June 2022 in Entropy
Verified
Journal Article
Open access
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Agnieszka Nowak-BrzezińskaAgnieszka Nowak-Brzezińska
Agnieszka Nowak-Brzezińska
Igor GaibeiIgor Gaibei
Igor Gaibei
In this article, we evaluate the efficiency and performance of two clustering algorithms: AHC (Agglomerative Hierarchical Clustering) and K−Means. We are aware that there are various linkage options and distance measures that influence the clustering results. We assess the quality of clustering using the Davies–Bouldin and Dunn cluster validity indexes. The main contribution of this research is to verify whether the quality of clusters without outliers is higher than those with outliers in the data. To do this, we compare and analyze outlier detection algorithms depending on the applied clustering algorithm. In our research, we use and compare the LOF (Local Outlier Factor) and COF (Connectivity-based Outlier Factor) algorithms for detecting outliers before and after removing 1%, 5%, and 10% of outliers. Next, we analyze how the quality of clustering has improved. In the experiments, three real data sets were used with a different number of instances.

31 December 2023
Verified
Book Chapter
Closed access
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Agnieszka Nowak-BrzezińskaAgnieszka Nowak-Brzezińska
Agnieszka Nowak-Brzezińska
Igor GaibeiIgor Gaibei
Igor Gaibei


17 November 2025
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Conference Paper
Open access
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Igor GaibeiIgor Gaibei
Igor Gaibei
Agnieszka Nowak-BrzezińskaAgnieszka Nowak-Brzezińska
Agnieszka Nowak-Brzezińska
This paper presents a novel approach to optimize inference in rule-based knowledge systems by introducing a clustering mechanism for rule organization. Rules are clustered using K-Means or Agglomerative Hierarchical Clustering (AHC) algorithms, with different distance measures and clustering strategies. We propose and evaluate four inference strategies based on different group representation methods (mean or median) and rule activation strategies (activation of one or all matching rules). Experimental studies on real knowledge bases show that clustering significantly improves inference performance while maintaining a satisfied inference success rate.

9 December 2022
Verified
Book Chapter
Closed access
PDF file
Agnieszka Nowak-BrzezińskaAgnieszka Nowak-Brzezińska
Agnieszka Nowak-Brzezińska
Igor GaibeiIgor Gaibei
Igor Gaibei