Vili Podgorelec

Prof. Dr. Vili Podgorelec

University of Maribor, Faculty of Electrical Engineering and Computer Science
orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

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

Representative Publications

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1 October 2002 in Journal of Medical Systems
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Journal Article
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Vili PodgorelecVili Podgorelec
Vili Podgorelec
PKPeter Kokol
Peter Kokol
BSBruno Stiglic
Bruno Stiglic
IRIvan Rozman
Ivan Rozman

1 September 2018 in Applied Sciences
Verified
Journal Article
Open access
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LBLucija Brezočnik
Lucija Brezočnik
IFIztok Fister
Iztok Fister
Vili PodgorelecVili Podgorelec
Vili Podgorelec
The increasingly rapid creation, sharing and exchange of information nowadays put researchers and data scientists ahead of a challenging task of data analysis and extracting relevant information out of data. To be able to learn from data, the dimensionality of the data should be reduced first. Feature selection (FS) can help to reduce the amount of data, but it is a very complex and computationally demanding task, especially in the case of high-dimensional datasets. Swarm intelligence (SI) has been proved as a technique which can solve NP-hard (Non-deterministic Polynomial time) computational problems. It is gaining popularity in solving different optimization problems and has been used successfully for FS in some applications. With the lack of comprehensive surveys in this field, it was our objective to fill the gap in coverage of SI algorithms for FS. We performed a comprehensive literature review of SI algorithms and provide a detailed overview of 64 different SI algorithms for FS, organized into eight major taxonomic categories. We propose a unified SI framework and use it to explain different approaches to FS. Different methods, techniques, and their settings are explained, which have been used for various FS aspects. The datasets used most frequently for the evaluation of SI algorithms for FS are presented, as well as the most common application areas. The guidelines on how to develop SI approaches for FS are provided to support researchers and analysts in their data mining tasks and endeavors while existing issues and open questions are being discussed. In this manner, using the proposed framework and the provided explanations, one should be able to design an SI approach to be used for a specific FS problem.

28 October 2020 in IEEE Access
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Journal Article
Open access
Grega VrbančičGrega Vrbančič
Grega Vrbančič
Vili PodgorelecVili Podgorelec
Vili Podgorelec
With the utilization of deep learning approaches, the key factors for a successful application are sufficient datasets with reliable ground truth, which are generally not easy to obtain, especially in the field of medicine. In recent years, this issue has been commonly addressed with the exploitation of transfer learning via fine-tuning, which enables us to start with a model, pre-trained for a specific task, and then fine-tune (train) only certain layers of the neural network for a related but different target task. However, the selection of fine-tunable layers is one of the major problems of such an approach. Since there is no general rule on how to select layers in order to achieve the highest possible performance, we developed the Differential Evolution based Fine-Tuning ( DEFT ) method for the selection of fine-tunable layers for a target dataset under the given constraints. The method was evaluated against the problem of identifying the osteosarcoma from the medical imaging dataset. The performance was compared against a conventionally trained convolutional neural network, a pre-trained model, and the model trained using a fine-tuning approach with manually handpicked fine-tunable layers. In terms of classification accuracy, our proposed method outperformed the compared methods by a margin of 4.45% to 32.75%.

2 October 2024 in Applied Sciences
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Mirka SaarelaMirka Saarela
Mirka Saarela
Vili PodgorelecVili Podgorelec
Vili Podgorelec
This systematic literature review employs the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to investigate recent applications of explainable AI (XAI) over the past three years. From an initial pool of 664 articles identified through the Web of Science database, 512 peer-reviewed journal articles met the inclusion criteria—namely, being recent, high-quality XAI application articles published in English—and were analyzed in detail. Both qualitative and quantitative statistical techniques were used to analyze the identified articles: qualitatively by summarizing the characteristics of the included studies based on predefined codes, and quantitatively through statistical analysis of the data. These articles were categorized according to their application domains, techniques, and evaluation methods. Health-related applications were particularly prevalent, with a strong focus on cancer diagnosis, COVID-19 management, and medical imaging. Other significant areas of application included environmental and agricultural management, industrial optimization, cybersecurity, finance, transportation, and entertainment. Additionally, emerging applications in law, education, and social care highlight XAI’s expanding impact. The review reveals a predominant use of local explanation methods, particularly SHAP and LIME, with SHAP being favored for its stability and mathematical guarantees. However, a critical gap in the evaluation of XAI results is identified, as most studies rely on anecdotal evidence or expert opinion rather than robust quantitative metrics. This underscores the urgent need for standardized evaluation frameworks to ensure the reliability and effectiveness of XAI applications. Future research should focus on developing comprehensive evaluation standards and improving the interpretability and stability of explanations. These advancements are essential for addressing the diverse demands of various application domains while ensuring trust and transparency in AI systems.

1 December 2020 in Data in Brief
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Journal Article
Open access
Grega VrbančičGrega Vrbančič
Grega Vrbančič
IFIztok Fister
Iztok Fister
Vili PodgorelecVili Podgorelec
Vili Podgorelec
Phishing stands for a fraudulent process, where an attacker tries to obtain sensitive information from the victim. Usually, these kinds of attacks are done via emails, text messages, or websites. Phishing websites, which are nowadays in a considerable rise, have the same look as legitimate sites. However, their backend is designed to collect sensitive information that is inputted by the victim. Discovering and detecting phishing websites has recently also gained the machine learning community’s attention, which has built the models and performed classifications of phishing websites. This paper presents two dataset variations that consist of 58,645 and 88,647 websites labeled as legitimate or phishing and allow the researchers to train their classification models, build phishing detection systems, and mining association rules.

1 January 2022 in Expert Systems with Applications
Verified
Journal Article
Closed access
Grega VrbančičGrega Vrbančič
Grega Vrbančič
Vili PodgorelecVili Podgorelec
Vili Podgorelec