Dimitrios Varsamis

Prof. Dimitrios Varsamis

orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

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18 July 2023 in Sensors
Verified
Journal Article
Open access
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EKElisavet Karapalidou
Elisavet Karapalidou
NANikolaos Alexandris
Nikolaos Alexandris
EAEfstathios Antoniou
Efstathios Antoniou
SVStavros Vologiannidis
Stavros Vologiannidis
John KalomirosJohn Kalomiros
John Kalomiros
DVDimitrios Varsamis
Dimitrios Varsamis
The advent of Industry 4.0 introduced new ways for businesses to evolve by implementing maintenance policies leading to advancements in terms of productivity, efficiency, and financial performance. In line with the growing emphasis on sustainability, industries implement predictive techniques based on Artificial Intelligence for the purpose of mitigating machine and equipment failures by predicting anomalies during their production process. In this work, a new dataset that was made publicly available, collected from an industrial blower, is presented, analyzed and modeled using a Sequence-to-Sequence Stacked Sparse Long Short-Term Memory Autoencoder. Specifically the right and left mounted ball bearing units were measured during several months of normal operational condition as well as during an encumbered operational state. An anomaly detection model was developed for the purpose of analyzing the operational behavior of the two bearing units. A stacked sparse Long Short-Term Memory Autoencoder was successfully trained on the data obtained from the left unit under normal operating conditions, learning the underlying patterns and statistical connections of the data. The model was evaluated by means of the Mean Squared Error using data from the unit’s encumbered state, as well as using data collected from the right unit. The model performed satisfactorily throughout its evaluation on all collected datasets. Also, the model proved its capability for generalization along with adaptability on assessing the behavior of equipment similar to the one it was trained on.

5 September 2012 in Multidimensional Systems and Signal Processing
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Journal Article
Closed access
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DVDimitrios Varsamis
Dimitrios Varsamis
NKNicholas P. Karampetakis
Nicholas P. Karampetakis

8 September 2025 in Computers
Verified
Journal Article
Open access
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AAAthanasios Angeioplastis
Athanasios Angeioplastis
JJohn Aliprantis
John Aliprantis
Markos KonstantakisMarkos Konstantakis
Markos Konstantakis
DVDimitrios Varsamis
Dimitrios Varsamis
TATsimpiris Alkiviadis
Tsimpiris Alkiviadis
Personalized learning environments increasingly rely on learner modeling techniques that integrate both explicit and implicit data sources. This study introduces a hybrid profiling methodology that combines psychometric data from an extended Felder–Silverman Learning Style Model (FSLSM) questionnaire with behavioral analytics derived from Moodle Learning Management System interaction logs. A structured mapping process was employed to associate over 200 unique log event types with FSLSM cognitive dimensions, enabling dynamic, behavior-driven learner profiles. Experiments were conducted across three datasets: a university dataset from the International Hellenic University, a public dataset from Kaggle, and a combined dataset totaling over 7 million log entries. Deep learning models including a Sequential Neural Network, BiLSTM, and a pretrained MLSTM-FCN were trained to predict student performance across regression and classification tasks. Results indicate moderate predictive validity: binary classification achieved practical, albeit imperfect accuracy, while three-class and regression tasks performed close to baseline levels. These findings highlight both the potential and the current constraints of log-based learner modeling. The contribution of this work lies in providing a reproducible integration framework and pipeline that can be applied across datasets, offering a realistic foundation for further exploration of scalable, data-driven personalization.

1 September 2013 in Applied Mathematics & Information Sciences
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Journal Article
Open access
PMParis Mastorocostas
Paris Mastorocostas
CHConstantinos Hilas
Constantinos Hilas
DVDimitrios Varsamis
Dimitrios Varsamis
SDStergiani Dova
Stergiani Dova

1 January 2014 in Applied Mathematics & Information Sciences
Verified
Journal Article
Closed access
DVDimitrios Varsamis
Dimitrios Varsamis
NKNicholas Karampetakis
Nicholas Karampetakis
PMParis Mastorocostas
Paris Mastorocostas

1 December 2012
Verified
Conference Paper
Closed access
DVDimitrios Varsamis
Dimitrios Varsamis
NKNicholas P. Karampetakis
Nicholas P. Karampetakis
The paper, proposes two new algorithms for the construction of a two-variable Newton-interpolation polynomial, for the special case where we have a rectangular basis with equidistant points. The complexity of the proposed algorithms is better than the ones given in [1] since it is based only on additions. One of the two algorithms is based on matrix multiplications and thus it is easily implemented in programming languages which supports such kind of operations.