Tomasz Orczyk

dblp:34/10620 · DBLP profile ↗
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16ranked-venue papers
2as first author
9since 2021 · last 2025
0000-0002-4664-8369ORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 16 · 2 first-author · 9 since 2021Databases, data management, data science and information retrieval · 5 · 3 since 2021
YearPublicationVenuePosition
2025 Evaluation of the Effectiveness of Ranking Methods in Detecting Feature Drift in Artificial and Real Data
Krzysztof Wrobel 0001, Piotr Porwik, Tomasz Orczyk
ACIIDS (2)3
2024 Open-source Python repository for data drift analysis
abstract
In this paper, we propose practical Python programs together with appropriate environments for the analysis of data stream drift, including the analysis of feature drift. The proposed approach contains a description of both, synthetic and real datasets. These datasets include different types of drifts like sudden, incremental, or gradual. Also, the location of the drift can be programmed. Additionally, we propose Java scripts that allow specifying the number and place of drift locations. The software is focused on prequential error methodology. Our proposition can be used by scientists interested in machine learning and concept drift detection because the proposed solution makes it easier to conduct practical experiments on that matter. The proposed solution allows for conducting experiments in a homogeneous programming environment. Versions of Python programs, stored in the GitHub repository, contain implementations of popular classifiers and drift detectors. The GitHub repository is located in the Public Domain.
Krzysztof Wrobel 0001, Piotr Porwik, Tomasz Orczyk
KES3
2024 Adaptive classifier ensemble for multibiometric Verification
abstract
The article presents a new method of multibiometric Verification that has been enhanced with dynamic classifier selection based on determining their competence. The competence of a classifier is defined, taking into account the type of biometric trait and the samples analyzed. The proposed approach not only allows for adaptive selection of classifiers to specific features and samples but also increases system efficiency by more effectively utilizing models that best match the given conditions. Classifier selection occurs dynamically, which enables the system to adjust flexibly to changing conditions and leverage the strengths of individual models while mitigating their weaknesses through compensation within the committee. The effectiveness of this method has been verified through experiments, which confirmed a significant improvement in person Verification effectiveness compared to methods without dynamic classifier selection.
Rafal Doroz, Tomasz Orczyk, Krzysztof Wrobel 0001, Piotr Porwik
KES2
2023 A new concept drift detection method based on the ranking of features in a data stream
abstract
The article presents a new concept drift detection method based on analyzing the importance of features of instances in the data stream. The data stream contains information about distribution patterns that reflect different concepts that may be hidden in the data stream. The presented drift detector concept uses information about the fluctuation of the most informative feature inside chunks of the data stream and compares it with the change of the same feature in neighbor chunks. In the case of data streams, the meaning of features can change over time. These changes affect the quality of the classification but can also be a significant indicator of ongoing concept drift. After detecting the drift, the classifier should be trained with the new dataset. But this issue is not addressed in this article. In this work, we propose a new concept drift detector in the data stream for the first time. This goal is achieved by observing the changing importance of features in different parts of the data stream. The proposed approach uses the feature significance measure as a drift detector. The obtained results indicate that the method can be introduced in practice. Because these are only preliminary results, in this paper, we focused on presenting the advantages of our strategy without comparison with other methods.
Krzysztof Wrobel 0001, Piotr Porwik, Tomasz Orczyk, Benjamin Mensah Dadzie
KES3
2023 A preliminary study on the dispersed classification system for recognizing safety of drivers' maneuvers
abstract
Riskful and aggressive driving are significant problems in road transportation. Numerous studies prove drivers’ behavior is critical in most road accidents and contributes significantly to fuel consumption and emissions. In an attempt to improve road safety, it is important to be able to detect such unskilful and irresponsible drivers on a mass scale. Thus an automated onboard driving safety assessment system is required. Transmitting amounts of telemetric data required to assess driving style is unpractical and economically unjustified, thus some data processing must take place in an Onboard Unit (OBU). As a first step in driving safety assessment is detecting maneuvers, this is the task, that can be done in the OBU. In this paper, we propose a Finite State Machine based algorithm, which could run on OBU and allows marking of basic maneuvers in the telemetry datastream. This allows the calculation of additional features, aggregation, and transmission of data useful for classification the of driving safety, and thus a vast reduction in data volume sent over the air. Also, an example of detecting unsafe maneuver using such aggregated data is given.
Tomasz Orczyk, Piotr Porwik, Rafal Doroz
KES1
2022 A Stable Method for Detecting Driver Maneuvers Using a Rule Classifier
Piotr Porwik, Tomasz Orczyk, Rafal Doroz
ACIIDS (1)2
2022 Features of Hand-Drawn Spirals for Recognition of Parkinson's Disease
Krzysztof Wrobel 0001, Rafal Doroz, Piotr Porwik, Tomasz Orczyk, Agnieszka Betkowska Cavalcante, Monika Grajzer
ACIIDS (2)4
2022 Multidimensional nearest neighbors classification based system for incomplete lip print identification
Rafal Doroz, Krzysztof Wrobel 0001, Tomasz Orczyk, Piotr Porwik, Marcin Cholewa
Expert Syst. Appl.3
2021 Classifier learning from difficult data on the example of missing features
abstract
This paper describes a novel method for classification based on a partly incomplete and low quality image data. The method has been tested on images with low quality areas such as partially corrupted, dark, or blurry images. Image data are converted to classifier input. As a result, we are dealing with missing data describing these areas, but the classifier was designed to work in the presence of missing data. The analysis of the literature shows that missing data have a negative impact on the operation of the learning algorithms. This field is still insufficient explored. In our method, we integrate complex image processing techniques, machine learning, and statistical methods under various contexts. The novelty of the presented approach is the structure of the classifier, which works in the presence of missing data on different principles than those used so far. Evaluation was performed on the basis of realistic images, collected before experiments. Multi-variant experimental protocols, specially designed in this work, confirmed the accuracy of the method. The obtained results help to better understand the methods of recognizing objects with incomplete data structures. Analysis techniques proposed in this paper are rapidly gaining in importance, so the proposed approach can be useful in many areas where the machine learning is employed.
Piotr Porwik, Tomasz Orczyk, Rafal Doroz
IJCNN2
2018 Liver fibrosis diagnosis support using the Dempster-Shafer theory extended for fuzzy focal elements
Sebastian Porebski, Piotr Porwik, Ewa Straszecka, Tomasz Orczyk
Eng. Appl. Artif. Intell.4
2016 Dynamic signature verification method based on association of features with similarity measures
Rafal Doroz, Piotr Porwik, Tomasz Orczyk
Neurocomputing3
2016 Signatures verification based on PNN classifier optimised by PSO algorithm
Piotr Porwik, Rafal Doroz, Tomasz Orczyk
Pattern Recognit.3
2015 Fusion of Granular Computing and k -NN Classifiers for Medical Data Support System
Marcin Bernas, Tomasz Orczyk, Piotr Porwik
ACIIDS (2)2
2015 Investigation of the Impact of Missing Value Imputation Methods on the k-NN Classification Accuracy
Tomasz Orczyk, Piotr Porwik
ICCCI (2)1
2015 The k-NN classifier and self-adaptive Hotelling data reduction technique in handwritten signatures recognition
abstract
The paper proposes a novel signature verification concept. This new approach uses appropriate similarity coefficients to evaluate the associations between the signature features. This association, called the new composed feature, enables the calculation of a new form of similarity between objects. The most important advantage of the proposed solution is case-by-case matching of similarity coefficients to a signature features, which can be utilized to assess whether a given signature is genuine or forged. The procedure, as described, has been repeated for each person presented in a signatures database. In the verification stage, a two-class classifier recognizes genuine and forged signatures. In this paper, a broad range of classifiers are evaluated. These classifiers all operate on features observed and computed during the data preparation stage. The set of signature composed features of a given person can be reduced what decrease verification error. Such a phenomenon does not occur for the raw features. The approach proposed was tested in a practical environment, with handwritten signatures used as the objects to be compared. The high level of signature recognition obtained confirms that the proposed methodology is efficient and that it can be adapted to accommodate as yet unknown features. The approach proposed can be incorporated into biometric systems.
Piotr Porwik, Rafal Doroz, Tomasz Orczyk
Pattern Anal. Appl.3
2013 Adaptive Splitting and Selection Method for Noninvasive Recognition of Liver Fibrosis Stage
Bartosz Krawczyk, Michal Wozniak 0001, Tomasz Orczyk, Piotr Porwik
ACIIDS (2)3