Panagiotis Anagnostou

Dr. Panagiotis Anagnostou

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Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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5 September 2025 in Neural Computing and Applications
Verified
Journal Article
Open access
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PTPanagiotis C. Theocharopoulos
Panagiotis C. Theocharopoulos
PAPanagiotis Anagnostou
Panagiotis Anagnostou
Spiros V. GeorgakopoulosSpiros V. Georgakopoulos
Spiros V. Georgakopoulos
Sotiris TasoulisSotiris Tasoulis
Sotiris Tasoulis
Vassilis PlagianakosVassilis Plagianakos
Vassilis Plagianakos
The utilization of large language models (LLMs) in research is becoming increasingly prevalent, as they offer advanced capabilities in processing and generating human-like text. However, this advancement comes with a significant trade-off in terms of time and computational costs. In this paper, we demonstrate that analyzing large text datasets with the use of LLMs can be performed efficiently in terms of both time and energy. For this purpose, we utilize the Llama pre-trained model. In more detail, we study the topic modeling task where the goal is to discover and identify topics in large text corpora. The basis of our approach is a hierarchical divisive clustering technique that clusters the data based on their semantic similarity, after employing a Sentence-BERT encoder, pre-trained on a variety of data across different tasks. Then, using an LLM, we identify topics for representative samples from each cluster. Additionally, we introduce a new evaluation method that leverages the capabilities of LLMs to assess the alignment between discovered topics and ground truth labels, providing a robust validation metric. Our findings indicate that it is possible to effectively reduce the computational cost of the topic modeling process compared to the direct application of LLMs and BERTopic, while simultaneously enhancing inference time and overall efficiency, thereby surpassing the current state-of-the-art capabilities of BERTopic.

18 April 2023 in Journal of Open Source Software
Verified
Journal Article
Open access
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PAPanagiotis Anagnostou
Panagiotis Anagnostou
Sotiris TasoulisSotiris Tasoulis
Sotiris Tasoulis
Vassilis PlagianakosVassilis Plagianakos
Vassilis Plagianakos
DTDimitris Tasoulis
Dimitris Tasoulis
This paper presents the HiPart package, an open-source native Python library that provides efficient and interpretable implementations of divisive hierarchical clustering algorithms. HiPart supports interactive visualizations for the manipulation of the execution steps allowing the direct intervention of the clustering outcome. This package is highly suited for Big Data applications as the focus has been given to the computational efficiency of the implemented clustering methodologies. The dependencies used are either Python build-in packages or highly maintained stable external packages. The software is provided under the MIT license. The package's source code and documentation can be found at GitHub.

17 June 2021 in Applied Artificial Intelligence
Verified
Journal Article
Closed access
PAPanagiotis Anagnostou
Panagiotis Anagnostou
Sotiris TasoulisSotiris Tasoulis
Sotiris Tasoulis
AVA. G. Vrahatis
A. G. Vrahatis
SGS. Georgakopoulos
S. Georgakopoulos
MPM. Prina
M. Prina
DPD. Panagiotakos
D. Panagiotakos
Preventive healthcare is a crucial pillar of health as it contributes to staying healthy and having immediate treatment when needed. Mining knowledge from longitudinal studies has the potential to significantly contribute to the improvement of preventive healthcare. Unfortunately, data originated from such studies are characterized by high complexity, huge volume, and a plethora of missing values. Machine Learning, Data Mining and Data Imputation models are utilized a part of solving these challenges, respectively. Toward this direction, we focus on the development of a complete methodology for the ATHLOS Project – funded by the European Union’s Horizon 2020 Research and Innovation Program, which aims to achieve a better interpretation of the impact of aging on health. The inherent complexity of the provided dataset lies in the fact that the project includes 15 independent European and international longitudinal studies of aging. In this work, we mainly focus on the HealthStatus (HS) score, an index that estimates the human status of health, aiming to examine the effect of various data imputation models to the prediction power of classification and regression models. Our results are promising, indicating the critical importance of data imputation in enhancing preventive medicine’s crucial role.

20 January 2021 in medRxiv
Verified
Preprint
Open access
PDF file
PAPanagiotis Anagnostou
Panagiotis Anagnostou
Sotiris TasoulisSotiris Tasoulis
Sotiris Tasoulis
Aristidis VrahatisAristidis Vrahatis
Aristidis Vrahatis
Spiros V. GeorgakopoulosSpiros V. Georgakopoulos
Spiros V. Georgakopoulos
MPMatthew Prina
Matthew Prina
DPDemosthenes Panagiotakos
Demosthenes Panagiotakos
Preventive healthcare is a crucial pillar of health as it contributes to staying healthy and having immediate treatment when needed. Mining knowledge from longitudinal studies has the potential to significantly contribute to the improvement of preventive healthcare. Unfortunately, data originated from such studies are characterized by high complexity, huge volume and a plethora of missing values. Machine Learning, Data Mining and Data Imputation models are utilized as part of solving the aforementioned challenges, respectively. Towards this direction, we focus on the development of a complete methodology for the ATHLOS (Ageing Trajectories of Health: Longitudinal Opportunities and Synergies) Project - funded by the European Union’s Horizon 2020 Research and Innovation Program, which aims to achieve a better interpretation of the impact of aging on health. The inherent complexity of the provided dataset lie in the fact that the project includes 15 independent European and international longitudinal studies of aging. In this work, we particularly focus on the HealthStatus (HS) score, an index that estimates the human status of health, aiming to examine the effect of various data imputation models to the prediction power of classification and regression models. Our results are promising, indicating the critical importance of data imputation in enhancing preventive medicine’s crucial role.

7 November 2025 in Pattern Recognition Letters
Verified
Journal Article
Closed access
PAPanagiotis Anagnostou
Panagiotis Anagnostou
Sotiris TasoulisSotiris Tasoulis
Sotiris Tasoulis
AVAristidis G. Vrahatis
Aristidis G. Vrahatis
Spiros V. GeorgakopoulosSpiros V. Georgakopoulos
Spiros V. Georgakopoulos
VPVassilis P. Plagianakos
Vassilis P. Plagianakos

17 November 2025 in Neural Computing and Applications
Verified
Journal Article
Open access
PDF file
PTPanagiotis C. Theocharopoulos
Panagiotis C. Theocharopoulos
PAPanagiotis Anagnostou
Panagiotis Anagnostou
Spiros V. GeorgakopoulosSpiros V. Georgakopoulos
Spiros V. Georgakopoulos
Sotiris TasoulisSotiris Tasoulis
Sotiris Tasoulis
Vassilis PlagianakosVassilis Plagianakos
Vassilis Plagianakos