Omiros Ragos

Prof. Omiros Ragos

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Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

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

Representative Publications

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21 March 2020 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MTMaria Tsiakmaki
Maria Tsiakmaki
Georgios KostopoulosGeorgios Kostopoulos
Georgios Kostopoulos
Sotiris KotsiantisSotiris Kotsiantis
Sotiris Kotsiantis
Omiros RagosOmiros Ragos
Omiros Ragos
Transferring knowledge from one domain to another has gained a lot of attention among scientists in recent years. Transfer learning is a machine learning approach aiming to exploit the knowledge retrieved from one problem for improving the predictive performance of a learning model for a different but related problem. This is particularly the case when there is a lack of data regarding a problem, but there is plenty of data about another related one. To this end, the present study intends to investigate the effectiveness of transfer learning from deep neural networks for the task of students’ performance prediction in higher education. Since building predictive models in the Educational Data Mining field through transfer learning methods has been poorly studied so far, we consider this study as an important step in this direction. Therefore, a plethora of experiments were conducted based on data originating from five compulsory courses of two undergraduate programs. The experimental results demonstrate that the prognosis of students at risk of failure can be achieved with satisfactory accuracy in most cases, provided that datasets of students who have attended other related courses are available.

20 December 2019 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MTMaria Tsiakmaki
Maria Tsiakmaki
Georgios KostopoulosGeorgios Kostopoulos
Georgios Kostopoulos
Sotiris KotsiantisSotiris Kotsiantis
Sotiris Kotsiantis
Omiros RagosOmiros Ragos
Omiros Ragos
Educational Data Mining (EDM) has emerged over the last two decades, concerning with the development and implementation of data mining methods in order to facilitate the analysis of vast amounts of data originating from a wide variety of educational contexts. Predicting students’ progression and learning outcomes, such as dropout, performance and course grades, is regarded among the most important tasks of the EDM field. Therefore, applying appropriate machine learning algorithms for building accurate predictive models is of outmost importance for both educators and data scientists. Considering the high-dimensional input space and the complexity of machine learning algorithms, the process of building accurate and robust learning models requires advanced data science skills, while is time-consuming and error-prone in most cases. In addition, choosing the proper method for a given problem formulation and configuring the optimal parameters’ values for a specific model is a demanding task, whilst it is often very difficult to understand and explain the produced results. In this context, the main purpose of the present study is to examine the potential use of advanced machine learning strategies on educational settings from the perspective of hyperparameter optimization. More specifically, we investigate the effectiveness of automated Machine Learning (autoML) for the task of predicting students’ learning outcomes based on their participation in online learning platforms. At the same time, we limit the search space to tree-based and rule-based models in order to achieving transparent and interpretable results. To this end, a plethora of experiments were carried out, revealing that autoML tools achieve consistently superior results. Hopefully our work will help nonexpert users (e.g., educators and instructors) in the field of EDM to conduct experiments with appropriate automated parameter configurations, thus achieving highly accurate and comprehensible results.

9 October 2010 in Astrophysics and Space Science
Verified
Journal Article
Closed access
PDF file
IHIoannis Haranas
Ioannis Haranas
Omiros RagosOmiros Ragos
Omiros Ragos
VMVasile Mioc
Vasile Mioc

12 May 2021 in Journal of Computing in Higher Education
Verified
Journal Article
Closed access
PDF file
MTMaria Tsiakmaki
Maria Tsiakmaki
Georgios KostopoulosGeorgios Kostopoulos
Georgios Kostopoulos
Sotiris KotsiantisSotiris Kotsiantis
Sotiris Kotsiantis
Omiros RagosOmiros Ragos
Omiros Ragos

1 August 2001 in Nonlinear Analysis
Verified
Journal Article
Closed access
Omiros RagosOmiros Ragos
Omiros Ragos
EPE.A. Perdios
E.A. Perdios
VKVassilis Kalantonis
Vassilis Kalantonis
Michael N VrahatisMichael N Vrahatis
Michael N Vrahatis

6 August 2010 in Astrophysics and Space Science
Verified
Journal Article
Closed access
PDF file
IHIoannis Haranas
Ioannis Haranas
Omiros RagosOmiros Ragos
Omiros Ragos