► Bakas, N. P., Papadaki, M., Vagianou, E., Christou, I., & Chatzichristofis, S. A. (2024). Integrating LLMs in higher education, through interactive problem solving and tutoring: Algorithmic approach and use cases. In M. Papadaki, M. Themistocleous, K. Al Marri, & M. Al Zarouni (Eds.), Information systems: 20th European, Mediterranean, and Middle Eastern Conference, EMCIS 2023, Dubai, United Arab Emirates, December 11-12, 2023, Proceedings, Part I (pp. 291–307). Springer. https://doi.org/10.1007/978-3-031-56478-9_21
Despite the concerns that recent developments in Large Language Models (LLMs) have raised, they undoubtedly revealed a novel potential of Artificial Intelligence (AI) algorithms in educational environments. Whether they are used for tutoring, in a manner similar to that of Intelligent Tutoring Systems (ITS), or to support assessment design and delivery, their impact in a learning setting is remarkable. In this paper, we propose an interactive tutoring approach, utilizing ChatGPT’s API. By exploiting ChatGPT’s programming interface, we can develop customized interactive problem-solving and tutoring sessions on specific topics of interest. The API’s versatility allows for dynamic interactions, fostering a deeper understanding of subjects taught and effective problem-solving skills. We demonstrate the application of the developed code in an applied educational setting with specific use cases.
► Christou, I. T., Efremidis, S., Klian, G., Meletiou, G. C., & Rassias, M. T. (2023). Using blockchains to support supply chain security. In N. J. Daras, P. M. Pardalos, & M. T. Rassias (Eds.), Analysis, cryptography and information science (pp. 21–46). World Scientific. https://doi.org/10.1142/9789811271922_0002
This chapter presents a novel approach for enhancing security and trust in supply chains through the use of blockchain technology. Supply chains lie at the base of world’s economy and typically comprise numerous stake-holders, which share no trust relationships while at the same time they need to interact and cooperate through complex processes. Cooperation between stakeholders presumes agreement between them at the different stages of their interaction, something that may be challenging to achieve. This chapter shows how blockchains can be used for logging stakeholder interactions, guaranteeing consensus among them, and implementing complex service agreements that may involve financial transactions through escrow accounts.
► Christou, I. T., Founti, M., Logothetis, M., Grigoropoulos, A., Stavrogiannis, C., & Atsonios, I. (2023, March 31). Optimal parameter estimation in NZEB renovation projects [Technical article]. BUILD UP: The European Portal for Energy Efficiency and Renewable Energy in Buildings. https://build-up.ec.europa.eu/en/resources-and-tools/articles/technical-article-optimal-parameter-estimation-nzeb-renovation
The PLURAL project developed key technologies, called Plug-and-Use kits (‘PnU kits’), for the deep renovation of EU buildings, aiming at reaching the goal of near-zero energy buildings (NZEB). A data mining algorithm is utilised to find all minimal configuration settings of a PnU kit that practically ensures the NZEB status of the building after the configuration is installed.
► Christou, I. T., Soldatos, J., Papadakis, T., Gutierrez-Rojas, D., & Nardelli, P. (2023). Feature selection via minimal covering sets for industrial internet of things applications. In Proceedings of the 19th International Conference on Distributed Computing in Smart Systems and the Internet of Things, DCOSS-IoT 2023 (pp. 562–567). https://doi.org/10.1109/dcoss-iot58021.2023.00092
High stakes decision making requires that any decision support systems must be able to come up with plausible explanations about the decisions they propose to the user. Several popular approaches to explaining black-box AI systems, such as neural networks, focus either on highlighting the features that matter the most in one particular decision as in the SHAP models, or on developing a local to the particular instance data model that is explainable by nature, such as a decision tree. ML systems that are by default explainable and/or interpretable, such as decision trees, or rule-based systems do not require such third-party approaches, as they are themselves explainable. Nevertheless, presenting a consistent (small) set of features to the users as explanations for any given proposed decision can increase the confidence of the users towards the reliability of the system. For this reason, we have developed a system that given a set of rules that hold on a training dataset, finds a minimal cardinality set of features that are used in a set of rules that together cover the entire training dataset. We develop a parallel heuristic algorithm for finding such a minimal variables set, and we show it outperforms all state-of-the-art optimization solvers for finding the solution to a MIP formulation of the problem. Experiments with data from use cases applying AI in public policy decision making as well as in medical use cases show that the proposed small set of features is sufficient to explain all the cases in the test dataset via rules containing only variables from the proposed set of features.
► Christou, I. T., Vagianou, E., & Vardoulias, G. (2024). Planning courses for student success at The American College of Greece. INFORMS Journal on Applied Analytics. https://doi.org/10.1287/inte.2022.0083
We are concerned with the personalized student course plan (PSCP) problem of optimizing the plan of courses students at the American College of Greece will need to take to complete their studies. We model the constraints set forth by the institution so that we guarantee the validity of all produced plans. We formulate several different objectives to optimize the resulting plan, including the fastest completion time, course difficulty balance, and maximization of the expected student grade point average given the student’s performance in passed courses. All resulting problems are mixed-integer linear programming problems with a number of binary variables, that is, the max number of terms times the number of courses available for the student to take. The resulting mathematical programming problem is solvable in less than 10 seconds on a modern commercial off-the-shelf PC, whereas the manual process used to take more than one hour of advising time for every student and, as measured by the objectives set forth, resulted in suboptimal schedules.
► Papadakis, T., Christou, I. T., Ipektsidis, C., Soldatos, J., & Amicone, A. (2024). Explainable and transparent artificial intelligence for public policymaking. Data & Policy, 6, Article e10. https://doi.org/10.1017/dap.2024.3
Nowadays public policymakers are offered with opportunities to take data-driven evidence-based decisions by analyzing the very large volumes of policy-related data that are generated through different channels (e.g., e-services, mobile apps, social media). Machine learning (ML) and artificial intelligence (AI) tehcnologies ease and automate the analysis of large policy-related datasets, which helps policymakers to realize a shift toward data-driven decisions. Nevertheless, the deployment and use of AI tools for public policy development is also associated with significant technical, political, and operation challenges. For instance, AI-based policy development solutions must be transparent and explainable to policymakers, while at the same time adhering to the mandates of emerging regulations such as the AI Act of the European Union. This paper introduces some of the main technical, operational, regulatory compliance challenges of AI-based policymaking. Accordingly, it introduces technological solutions for overcoming them, including: (i) a reference architecture for AI-based policy development, (ii) a virtualized cloud-based tool for the specification and implementation of ML-based data-driven policies, (iii) a ML framework that enables the development of transparent and explainable ML models for policymaking, and (iv) a set of guidelines for using the introduced technical solutions to achieve regulatory compliance. The paper ends up illustrating the validation and use of the introduced solutions in real-life public policymaking cases for various local governments.