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Publications

Publications by HASLab

2024

Review of commercial flexibility products and market platforms

Authors
Rodrigues, L; Ganesan, K; Retorta, F; Coelho, F; Mello, J; Villar, J; Bessa, R;

Publication
2024 20TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET, EEM 2024

Abstract
The European Union is pushing its members states to implement regulations that incentivize distribution system operators to procure flexibility to enhance grid operation and planning. Since flexibility should be obtained using market-based solutions, when possible, flexibility market platforms become essential tools to harness consumer-side flexibility, supporting its procurement, trading, dispatch, and settlement. These reasons have led to the appearance of multiple flexibility market platforms with different structure and functionalities. This work provides a comprehensive description of the main flexibility platforms operating in Europe and provides a concise review of the platform main characteristics and functionalities, including their user segment, flexibility trading procedures, settlement processes, and flexibility products supported.

2024

GDBN, a Customer-centric Digital Platform to Support the Value Chain of Flexibility Provision

Authors
Coelho, F; Rodrigues, L; Mello, J; Villar, J; Bessa, R;

Publication
2024 20TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET, EEM 2024

Abstract
This paper proposes an original framework for a flexibility-centric value chain and describes the pre-specification of the Grid Data and Business Network (GDBN), a digital platform to provide support to the flexibility value chain activities. First, it outlines the structure of the value chain with the most important tasks and actors in each activity. Next, it describes the GDBN concept, including stakeholders' engagement and conceptual architecture. It presents the main GDBN services to support the flexibility value chain, including, matching consumers and assets and service providers, assets installation and operationalization to provide flexibility, services for energy communities and services, for consumers, aggregators, and distribution systems operators, to participate in flexibility markets. At last, it details the workflow and life cycle management of this platform and discusses candidate business models that could support its implementation in real-life scenarios.

2024

Impact of Traffic Sampling on LRD Estimation

Authors
Mendes, J; Lima, SR; Carvalho, P; Silva, JMC;

Publication
INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 1, WORLDCIST 2023

Abstract
Network traffic sampling is an effective method for understanding the behavior and dynamics of a network, being essential to assist network planning and management. Tasks such as controlling Service Level Agreements or Quality of Service, as well as planning the capacity and the safety of a network can benefit from traffic sampling advantages. The main objective of this paper is focused on evaluating the impact of sampling network traffic on: (i) achieving a low-overhead estimation of the network state and (ii) assessing the statistical properties that sampled network traffic presents regarding the eventual persistence of LongRange Dependence (LRD). For that, different Hurst parameter estimators have been used. Facing the impact of LRD on network congestion and traffic engineering, this work will help clarify the suitability of distinct sampling techniques in accurate network analysis.

2024

Expert Systems in Information Security: A Comprehensive Exploration of Awareness Strategies Against Social Engineering Attacks

Authors
Cardoso, WR; Ribeiro, ADL; da Silva, JMC;

Publication
GOOD PRACTICES AND NEW PERSPECTIVES IN INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 2, WORLDCIST 2024

Abstract
This article delves into the pivotal role of expert systems in bolstering information security, with a specific emphasis on their effectiveness in awareness and training programs aimed at thwarting social engineering attacks. Employing a snowball methodology, the research expands upon seminal works, highlighting the intersection between expert systems and cybersecurity. The study identifies a gap in current understanding and aims to contribute valuable insights to the field. By analyzing five key articles as seeds, the research explores the landscape of expert systems in information security, emphasizing their potential impact on cultivating robust defenses against evolving cyber threats.

2024

VQC-based reinforcement learning with data re-uploading: performance and trainability

Authors
Coelho, R; Sequeira, A; Santos, LP;

Publication
QUANTUM MACHINE INTELLIGENCE

Abstract
Reinforcement learning (RL) consists of designing agents that make intelligent decisions without human supervision. When used alongside function approximators such as Neural Networks (NNs), RL is capable of solving extremely complex problems. Deep Q-Learning, a RL algorithm that uses Deep NNs, has been shown to achieve super-human performance in game-related tasks. Nonetheless, it is also possible to use Variational Quantum Circuits (VQCs) as function approximators in RL algorithms. This work empirically studies the performance and trainability of such VQC-based Deep Q-Learning models in classic control benchmark environments. More specifically, we research how data re-uploading affects both these metrics. We show that the magnitude and the variance of the model's gradients remain substantial throughout training even as the number of qubits increases. In fact, both increase considerably in the training's early stages, when the agent needs to learn the most. They decrease later in the training, when the agent should have done most of the learning and started converging to a policy. Thus, even if the probability of being initialized in a Barren Plateau increases exponentially with system size for Hardware-Efficient ansatzes, these results indicate that the VQC-based Deep Q-Learning models may still be able to find large gradients throughout training, allowing for learning.

2024

Patient-Centric Health Data Sovereignty: An Approach Using Proxy Re-Encryption

Authors
Rodrigues, B; Amorim, I; Silva, I; Mendes, A;

Publication
COMPUTER SECURITY. ESORICS 2023 INTERNATIONAL WORKSHOPS, PT I

Abstract
The exponential growth in the digitisation of services implies the handling and storage of large volumes of data. Businesses and services see data sharing and crossing as an opportunity to improve and produce new business opportunities. The health sector is one area where this proves to be true, enabling better and more innovative treatments. Notwithstanding, this raises concerns regarding personal data being treated and processed. In this paper, we present a patient-centric platform for the secure sharing of health records by shifting the control over the data to the patient, therefore, providing a step further towards data sovereignty. Data sharing is performed only with the consent of the patient, allowing it to revoke access at any given time. Furthermore, we also provide a break-glass approach, resorting to Proxy Re-encryption (PRE) and the concept of a centralised trusted entity that possesses instant access to patients' medical records. Lastly, an analysis is made to assess the performance of the platform's key operations, and the impact that a PRE scheme has on those operations.

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