2024
Authors
Pinto, J; Grasel, B; Baptista, J;
Publication
ELECTRONICS
Abstract
High-frequency (HF) emissions, referred to as supraharmonics (SHs), are proliferating in low- and medium-voltage networks due to the increasing use of technologies that generate distortions in the 2 kHz to 150 kHz range. The propagation of SHs through the electrical grid causes interference with power supply components and end-user equipment. With the increasing frequency of these incidents, it is imperative to establish guidelines and regulations that facilitate diagnosis and limit the amount of emissions injected into the electrical grid. The proliferation of SH emissions from active power electronics devices is a significant concern, especially considering the growing importance of photovoltaic (PV) systems in the context of climate change. The aim of this paper is to address and analyze the emissions from different PV inverters present in an electrical network. Several scenarios were simulated to understanding and identifying possible correlations. This study examines real signals from PV systems, which exhibit narrowband, broadband and time-varying emissions. This paper concludes by emphasizing the need for specific regulations for this frequency range while also providing indications for future research.
2024
Authors
Gomes, I; Sousa, JVJ; Sousa, J; Lucas, A;
Publication
2024 20TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET, EEM 2024
Abstract
Self-consumption regulations are leading to the emergence of new business models proposed by new players and causing traditional players to make new proposals to take advantage of the new business opportunities. In this context, traditional retailers are assessing self-consumption business models, offering management services for self-consumption structures, or the installation of distributed resources, such as solar panels or batteries. Some of the new business models being proposed by electricity suppliers are related to virtual battery services. Indeed, suppliers can, in the free retail market, create innovative tariffs, and design them to make their customers believe they own and manage a battery, even if it does not correspond to a physical battery in the grid. This paper analyses the business model of a supplier offering a virtual battery service, comparing it to the installation of a physical battery, showing that it has no significant benefits compared to more simple approaches.
2024
Authors
Mesquita, M; Simões, AC; Teles, V; Dalmarco, G;
Publication
Lecture Notes in Mechanical Engineering
Abstract
Companies are putting more emphasis on the customer experience, associating services with their physical products with the help of emerging technologies. At the same time, several actors participating in research and innovation projects, such as universities, research institutes, and service providers, are involved in the value co-creation process. Thus, this study describes how digitalisation and servitisation in the context of participation in research and innovation projects contributed to innovation in industrial companies’ business model (BM). Qualitative exploratory research took place, collecting data through interviews with twelve key actors in industrial companies. The interviewees were professionals in management and R&D areas and founders from nine European countries who participated in six research and innovation European projects. The exchange of knowledge and experiences between the different actors of the innovation ecosystem influences this. From a practical point of view, research provides managers of industrial companies with the best practices and describes the main changes observed in the BM Canvas. This study also contributes to categorising companies in terms of their service maturity by associating factors other than servitisation, such as digitalisation and the actors of the research and innovation projects. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
2024
Authors
Almeida, JB; Olmos, SA; Barbosa, M; Barthe, G; Dupressoir, F; Grégoire, B; Laporte, V; Lechenet, JC; Low, C; Oliveira, T; Pacheco, H; Quaresma, M; Schwabe, P; Strub, PY;
Publication
ADVANCES IN CRYPTOLOGY - CRYPTO 2024, PT II
Abstract
We present a formally verified proof of the correctness and IND-CCA security of ML-KEM, the Kyber-based Key Encapsulation Mechanism (KEM) undergoing standardization by NIST. The proof is machine-checked in EasyCrypt and it includes: 1) A formalization of the correctness (decryption failure probability) and IND-CPA security of the Kyber base public-key encryption scheme, following Bos et al. at Euro S&P 2018; 2) A formalization of the relevant variant of the Fujisaki-Okamoto transform in the Random Oracle Model (ROM), which follows closely (but not exactly) Hofheinz, Hovelmanns and Kiltz at TCC 2017; 3) A proof that the IND-CCA security of the ML-KEM specification and its correctness as a KEM follows from the previous results; 4) Two formally verified implementations of ML-KEM written in Jasmin that are provably constant-time, functionally equivalent to the ML-KEM specification and, for this reason, inherit the provable security guarantees established in the previous points. The top-level theorems give self-contained concrete bounds for the correctness and security of ML-KEM down to (a variant of) Module-LWE. We discuss how they are built modularly by leveraging various EasyCrypt features.
2024
Authors
Silva, P; Moreira, AC; Almeida, S; Mountinho, V;
Publication
ASIA PACIFIC JOURNAL OF MARKETING AND LOGISTICS
Abstract
PurposeIn a society that encourages consumption, attributes such as exclusivity and social recognition are important in what is intended to be restricted to a certain exclusive segment. Luxury is something that is more desirable than necessary. This study develops and tests a model that analyses the brand loyalty-risk relationship in the luxury watch market.Design/methodology/approachTo test the proposed research model, a sample of 306 international consumers and enthusiasts of luxury brand watches was collected. The data were analysed using structural equation modelling.FindingsThe results show that perceived quality has a negative indirect influence on brand risk and brand trust has a strong direct negative effect on brand risk. However, the findings also show that in the luxury market, the greater the affection for the brand, the greater the risk perceived by consumers.Research limitations/implicationsThe study was conducted in a single market, luxury watches and the sample includes both enthusiasts and consumers of the luxury brands.Practical implicationsManagers should be aware of the double-edged role of brand affect on brand risk. The quality of a brand and the trust in its promise decrease the risk to the consumer.Originality/valueThis pioneering study is one of the first to approach an underexplored topic as is the case of the risk associated with a brand in the context of the luxury goods market. Moreover, it relies on an international sample composed of consumers from several countries.
2024
Authors
Almeida, F;
Publication
Sustainable Smart Cities and the Future of Urban Development
Abstract
Municipalities are key players in their role as sustainable development planners and have a responsibility to change behavior at the local level. This study uses a panel of French municipalities to explore their role in promoting responsible consumption and production practices. A questionnaire was set up to obtain data from 186 citizens, of which 77 come from rural areas and 109 from urban zones. The findings reveal that French municipalities have a wide influence on the consumption and more responsible production of individuals through their actions. They encourage inhabitants to reduce energy and water consumption, waste management, and local and organic consumption. French citizens are mainly influenced by social and economic factors, while political and marketing factors are of little relevance. Furthermore, there are no differences in the importance and involvement of citizens in responsible consumption and production actions between rural and urban municipalities. © 2025 by IGI Global Scientific Publishing. All rights reserved.
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