THEMISTOKLIS TSATALAS

Dr. THEMISTOKLIS TSATALAS

University of Thessaly
orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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1 October 2022 in Diagnostics
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Christos KokkotisChristos Kokkotis
Christos Kokkotis
GGGeorgios Giarmatzis
Georgios Giarmatzis
EGErasmia Giannakou
Erasmia Giannakou
SMSerafeim Moustakidis
Serafeim Moustakidis
THEMISTOKLIS TSATALASTHEMISTOKLIS TSATALAS
THEMISTOKLIS TSATALAS
NANikolaos Aggelousis
Nikolaos Aggelousis
Stroke is an acute neurological dysfunction attributed to a focal injury of the central nervous system due to reduced blood flow to the brain. Nowadays, stroke is a global threat associated with premature death and huge economic consequences. Hence, there is an urgency to model the effect of several risk factors on stroke occurrence, and artificial intelligence (AI) seems to be the appropriate tool. In the present study, we aimed to (i) develop reliable machine learning (ML) prediction models for stroke disease; (ii) cope with a typical severe class imbalance problem, which is posed due to the stroke patients’ class being significantly smaller than the healthy class; and (iii) interpret the model output for understanding the decision-making mechanism. The effectiveness of the proposed ML approach was investigated in a comparative analysis with six well-known classifiers with respect to metrics that are related to both generalization capability and prediction accuracy. The best overall false-negative rate was achieved by the Multi-Layer Perceptron (MLP) classifier (18.60%). Shapley Additive Explanations (SHAP) were employed to investigate the impact of the risk factors on the prediction output. The proposed AI method could lead to the creation of advanced and effective risk stratification strategies for each stroke patient, which would allow for timely diagnosis and the right treatments.

23 November 2018 in Scandinavian Journal of Medicine & Science in Sports
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Minas MinaMinas Mina
Minas Mina
Anthony BlazevichAnthony Blazevich
Anthony Blazevich
THEMISTOKLIS TSATALASTHEMISTOKLIS TSATALAS
THEMISTOKLIS TSATALAS
GGGiannis Giakas
Giannis Giakas
LSLaurent B. Seitz
Laurent B. Seitz
AKAnthony D Kay
Anthony D Kay

5 May 2023 in Future Internet
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Journal Article
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SMSerafeim Moustakidis
Serafeim Moustakidis
Spyridon PlakiasSpyridon Plakias
Spyridon Plakias
Christos KokkotisChristos Kokkotis
Christos Kokkotis
THEMISTOKLIS TSATALASTHEMISTOKLIS TSATALAS
THEMISTOKLIS TSATALAS
DTDimitrios Tsaopoulos
Dimitrios Tsaopoulos
Understanding the performance indicators that contribute to the final score of a football match is crucial for directing the training process towards specific goals. This paper presents a pipeline for identifying key team-level performance variables in football using explainable ML techniques. The input data includes various team-specific features such as ball possession and pass behaviors, with the target output being the average scoring performance of each team over a season. The pipeline includes data preprocessing, sequential forward feature selection, model training, prediction, and explainability using SHapley Additive exPlanations (SHAP). Results show that 14 variables have the greatest contribution to the outcome of a match, with 12 having a positive effect and 2 having a negative effect. The study also identified the importance of certain performance indicators, such as shots, chances, passing, and ball possession, to the final score. This pipeline provides valuable insights for coaches and sports analysts to understand which aspects of a team’s performance need improvement and enable targeted interventions to improve performance. The use of explainable ML techniques allows for a deeper understanding of the factors contributing to the predicted average team score performance.

Verified
Journal Article
Open access
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Spyridon PlakiasSpyridon Plakias
Spyridon Plakias
SMSerafeim Moustakidis
Serafeim Moustakidis
Christos KokkotisChristos Kokkotis
Christos Kokkotis
THEMISTOKLIS TSATALASTHEMISTOKLIS TSATALAS
THEMISTOKLIS TSATALAS
MPMarina Papalexi
Marina Papalexi
DTDimitrios Tsaopoulos
Dimitrios Tsaopoulos
Identifying and measuring soccer playing styles is a very important step toward a more effective performance analysis. Exploring the different game styles that a team can adopt to enable a great performance remains under-researched. To address this challenge and identify new directions in future research in the area, this paper conducted a critical review of 40 research articles that met specific criteria. Following the 22-item Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, this scoping review searched for literature on Google Scholar, Web of Science, and Pub Med databases. The descriptive and thematic analysis found that the objectives of the identified papers can be classified into three main categories (recognition and effectiveness of playing styles and contextual variables that affect them). Critically reviewing the studies, the paper concluded that: (i) factor analysis seems to be the best technique among inductive statistics; (ii) artificial intelligence (AI) opens new horizons in performance analysis, and (iii) there is a need for further research on the effectiveness of different playing styles, as well as on the impact of contextual variables on them.

9 April 2010 in Arthroscopy
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Journal Article
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ATAlexander Tsarouhas
Alexander Tsarouhas
MIMichael Iosifidis
Michael Iosifidis
DKDimitrios Kotzamitelos
Dimitrios Kotzamitelos
GSGiannis Spyropoulos
Giannis Spyropoulos
THEMISTOKLIS TSATALASTHEMISTOKLIS TSATALAS
THEMISTOKLIS TSATALAS
GGGiannis Giakas
Giannis Giakas

Verified
Journal Article
Open access
PDF file
Spyridon PlakiasSpyridon Plakias
Spyridon Plakias
THEMISTOKLIS TSATALASTHEMISTOKLIS TSATALAS
THEMISTOKLIS TSATALAS
VAVasilis Armatas
Vasilis Armatas
DTDimitrios Tsaopoulos
Dimitrios Tsaopoulos
GGGiannis Giakas
Giannis Giakas
The game of soccer is complex and unpredictable, demanding multifaceted strategies for success. Performance analysis has evolved, focusing on key performance indicators (KPIs) to determine the factors that most significantly influence a team’s success or failure during matches. Traditional performance analysis methods have emphasized quantifiable data like physical exertion and basic play events but often neglected the subtler tactical dimensions that could significantly impact game outcomes. This study aimed to fill the gap in the current literature by creating a comprehensive framework that incorporates tactical situations as KPIs. The objective was to examine whether specific playing styles adopted by teams in various tactical situations and phases of the game could predict the outcome of matches. A dataset comprising all First Division Championship matches from 11 different European countries for the 2021–2022 season was analyzed. Variables representing tactical situations were correlated with match outcomes using a Generalized Estimating Equation framework. The model was specified with a binomial distribution and a logit link function. Statistical significance was determined using Wald χ2 tests with a significance level set at p < 0.05. The study’s findings revealed that possession style, counterattacking during offensive transitions, and a balanced aggressive defensive strategy significantly increase a team’s chances of victory. It also showed that successful teams tend to focus on central attacks, minimize crossing, and execute strategic plays that lead to final attempts on goal with minimal ball possession. The above findings demonstrate that adopting certain tactical approaches significantly influences soccer match outcomes, highlighting the importance of considering tactical aspects as KPIs.