Rafal Doroz

dblp:20/8977 · DBLP profile ↗
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23ranked-venue papers
7as first author
10since 2021 · last 2025
0000-0001-6103-1175ORCID · verified

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

Artificial intelligence and machine learning · 22 · 6 first-author · 10 since 2021Databases, data management, data science and information retrieval · 6 · 2 first-author · 3 since 2021
YearPublicationVenuePosition
2025 Enhancing Accuracy and Stability in XAI for Context-Specific Applications
Bartosz Szostak, Rafal Doroz, Magdalena Marker
ACIIDS (2)2
2025 Gait-based human classification using spectrograms analysis and deep learning
abstract
Gait is a routine activity performed daily by every able-bodied individual. Recent studies have demonstrated its potential as a reliable factor in behavioral biometrics for user recognition, offering high accuracy. This study presents a novel approach to human gait analysis leveraging spectrogram representations of accelerometer signals combined with deep learning techniques. In proposed methods time-series accelerometer data is transformed into spectrograms using the Short-Time Fourier Transform (STFT). This conversion enables the utilization of convolutional neural networks (CNNs), which are highly effective in image classification tasks, to identify distinctive gait patterns. The architecture of the neural network was carefully optimized through a series of empirical experiments, adjusting the number and order of layers to achieve the best classification performance. The effectiveness of the proposed solution was validated on both a custom dataset and a publicly available benchmark dataset. The proposed CNN-based approach achieved a prediction accuracy of 92.03%, outperforming traditional models based on raw sensor data and demonstrating competitive performance relative to state-of-the-art methods, such as ResNet-based CNNs, GRU networks, and the M-GaitFormer architecture. These results confirm the advantages of time-frequency feature extraction for gait recognition. This work demonstrates the potential of using everyday mobile devices equipped with accelerometers for biometric authentication based on behavioral traits. Future research directions include extending the model to multi-sensor fusion (e.g., incorporating gyroscope data), enhancing robustness across diverse walking conditions, and developing efficient implementations for real-time gait recognition on mobile platforms.
Jakub Mrozinski, Rafal Doroz
KES2
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
KES1
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
KES3
2022 A Stable Method for Detecting Driver Maneuvers Using a Rule Classifier
Piotr Porwik, Tomasz Orczyk, Rafal Doroz
ACIIDS (1)3
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)2
2022 Diagnosing Parkinson's disease using features of hand-drawn spirals
abstract
This paper proposes a novel method for diagnosing Parkinson's disease, based on a hand-drawn spirals and features generated from them. Analyzed spirals were drawn on a drawing tablet by both ill and healthy subjects. During drawing, coordinates of points of the spiral, pressure and angle of the pen at that point, and timestamp were registered. On the basis of the registered data, a set of features has been proposed, by means of which the classification was performed. For classification, several of the most popular machine learning methods were used, for which the accuracy of Parkinson's disease recognition was determined. The study showed that the proposed set of features enables the effective diagnosis of Parkinson's disease. The experiments were conducted on a publicly available database from the UCI archives. This database contains drawings of spirals made by people with Parkinson's disease and healthy people.
Krzysztof Wrobel 0001, Rafal Doroz
KES2
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.1
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
IJCNN3
2021 Adaptation of the idea of concept drift to some behavioral biometrics: Preliminary studies
Piotr Porwik, Rafal Doroz
Eng. Appl. Artif. Intell.2
2019 An ensemble learning approach to lip-based biometric verification, with a dynamic selection of classifiers
Piotr Porwik, Rafal Doroz, Krzysztof Wrobel 0001
Expert Syst. Appl.2
2018 Online signature verification modeled by stability oriented reference signatures
Rafal Doroz, Przemyslaw Kudlacik, Piotr Porwik
Inf. Sci.1
2018 Personal identification utilizing lip print furrow based patterns. A new approach
Krzysztof Wrobel 0001, Rafal Doroz, Piotr Porwik, Marcin Bernas
Pattern Recognit.2
2017 Computer User Verification Based on Typing Habits and Finger-Knuckle Analysis
Hossein Safaverdi, Tomasz E. Wesolowski, Rafal Doroz, Krzysztof Wrobel 0001, Piotr Porwik
ICCCI (2)3
2017 Using a Probabilistic Neural Network for lip-based biometric verification
Krzysztof Wrobel 0001, Rafal Doroz, Piotr Porwik, Jacek Naruniec, Marek Kowalski
Eng. Appl. Artif. Intell.2
2016 A New Personal Verification Technique Using Finger-Knuckle Imaging
Rafal Doroz, Krzysztof Wrobel 0001, Piotr Porwik, Hossein Safaverdi, Michal Senejko, Janusz Jezewski, Pawel Popielski, Slawomir Wilczynski, Robert Koprowski, Zygmunt Wróbel
ICCCI (2)1
2016 The Matching Method for Rectified Stereo Images Based on Minimal Element Distance and RGB Component Analysis
Pawel Popielski, Robert Koprowski, Zygmunt Wróbel, Slawomir Wilczynski, Rafal Doroz, Krzysztof Wrobel 0001, Piotr Porwik
ICCCI (2)5
2016 Dynamic signature verification method based on association of features with similarity measures
Rafal Doroz, Piotr Porwik, Tomasz Orczyk
Neurocomputing1
2016 Signatures verification based on PNN classifier optimised by PSO algorithm
Piotr Porwik, Rafal Doroz, Tomasz Orczyk
Pattern Recognit.2
2015 Detecting the Reference Point in Fingerprint Images with the Use of the High Curvature Points
Rafal Doroz, Krzysztof Wrobel 0001, Malgorzata Palys
ACIIDS (2)1
2015 Lip Print Recognition Method Using Bifurcations Analysis
Krzysztof Wrobel 0001, Rafal Doroz, Malgorzata Palys
ACIIDS (2)2
2015 The New Multilayer Ensemble Classifier for Verifying Users Based on Keystroke Dynamics
Rafal Doroz, Piotr Porwik, Hossein Safaverdi
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.2