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Publications

2024

The OPEVA Manifest: OPtimisation of Electrical Vehicle Autonomy, a Research and Innovation project

Authors
Kanak, A; Ergün, S; Arif, I; Ergün, SH; Bektas, C; Atalay, AS; Herkiloglu, O; Defossez, D; Yazici, A; Ferreira, LL; Strelec, M; Kubicek, K; Cech, M; Davoli, L; Belli, L; Ferrari, G; Bayar, D; Kafali, A; Karamavus, Y; Sofu, AM; Hartavi Karci, AE; Constant, P;

Publication
Open Research Europe

Abstract
Electromobility is a critical component of Europe’s strategy to create a more sustainable society and support the European Green Transition while enhancing quality of life. Electrification also plays an important role in securing Europe’s position in the growing market of electric and autonomous vehicles (EAV). The EU-funded OPEVA project aims to take a big step towards deployment of sustainable electric vehicles by means of optimising their support in an ecosystem. Specifically, the project focuses on analysing and designing optimisation architecture, reducing battery charging time, and developing infrastructure, as well as reporting on the driver-oriented human factors. Overall, OPEVA’s goal is to enhance EAV market penetration and adoption, making them more accessible and convenient. The aim of this paper is to inform the European automotive, transportation, energy and mobility community be presenting the OPEVA manifestation, and the overall solution strategy solidified through the progress throughout the first year of the project.

2024

Bare PAKE: Universally Composable Key Exchange from Just Passwords

Authors
Barbosa, M; Gellert, K; Hesse, J; Jarecki, S;

Publication
ADVANCES IN CRYPTOLOGY - CRYPTO 2024, PT II

Abstract
In the past three decades, an impressive body of knowledge has been built around secure and private password authentication. In particular, secure password-authenticated key exchange (PAKE) protocols require only minimal overhead over a classical Diffie-Hellman key exchange. PAKEs are also known to fulfill strong composable security guarantees that capture many password-specific concerns such as password correlations or password mistyping, to name only a few. However, to enjoy both round-optimality and strong security, applications of PAKE protocols must provide unique session and participant identifiers. If such identifiers are not readily available, they must be agreed upon at the cost of additional communication flows, a fact which has been met with incomprehension among practitioners, and which hindered the adoption of provably secure password authentication in practice. In this work, we resolve this issue by proposing a new paradigm for truly password-only yet securely composable PAKE, called bare PAKE. We formally prove that two prominent PAKE protocols, namely CPace and EKE, can be cast as bare PAKEs and hence do not require pre-agreement of anything else than a password. Our bare PAKE modeling further allows to investigate a novel reusability property of PAKEs, i.e., whether n(2) pairwise keys can be exchanged from only n messages, just as the Diffie-Hellman non-interactive key exchange can do in a public-key setting. As a side contribution, this add-on property of bare PAKEs leads us to observe that some previous PAKE constructions relied on unnecessarily strong, reusable building blocks. By showing that non-reusable tools suffice for standard PAKE, we open a new path towards round-optimal post-quantum secure password-authenticated key exchange.

2024

Use of a Paclitaxel Drug-Eluting Stent for the Treatment of Hemodialysis Access Outflow Stenosis

Authors
Pinelo, A; Almeida, P; Loureiro, L; Rego, D; Teixeira, S; Mendes, D; Teles, P; Sousa, C; de Matos, N;

Publication
JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY

Abstract
Purpose: To evaluate the outcomes and durability of drug -eluting stents (DESs) for the treatment of hemodialysis access outflow stenosis. Material and Methods: A single -center retrospective analysis was conducted of all patients with hemodialysis vascular access outflow stenosis treated with a paclitaxel-coated DES (Eluvia; Boston Scientific, Marlborough, Massachusetts) between January 2020 and July 2022. A total of 34 DESs were implanted to treat outflow stenosis in 32 patients. Primary target lesion patency after stent deployment was the main outcome. Comparison between the time interval free from target lesion reintervention (TLR) after previous plain balloon angioplasty (PBA) and that after stent deployment for the same target lesion was considered a secondary outcome. Results: The primary patency at 6, 12, and 18 months was 63.1%, 47.6%, and 41.7%, respectively. The secondary patency rate was 100% at 18 months. The median time interval free from TLR increased from 4.1 to 11.9 months (P < .001). No adverse events were observed during the median follow-up period of 387 days. Conclusions: The patency rates after use of DES for hemodialysis access outflow stenosis were comparable with results for drug -coated balloons and stent grafts, addressing recoil and minimizing the risk of jailing by a covered stent.

2024

Grid-Forming Photovoltaic Generators Operating During Power System Transients

Authors
Roldán-Pérez, J; Prodanovic, M; Rodrigues, J; Moreira, C;

Publication
IEEE 15TH INTERNATIONAL SYMPOSIUM ON POWER ELECTRONICS FOR DISTRIBUTED GENERATION SYSTEMS, PEDG 2024

Abstract
Grid-forming (GF) converters based on renewable energy sources are a fundamental piece of future power systems. In particular, the design specifications of GF converters in photovoltaic (PV) applications are difficult to meet because PV inverters lack energy storage. The operation of GF-PV inverters under normal conditions has already been addressed in the existing literature. However, the operation in case of large disturbances, such as faults, has rarely been explored. In this paper, a GF controller for a two-stage PV inverter that is robust against faults is presented. This control system includes several improvements compared to the traditional GF controller. Power feedforwards and saturations are applied to improve the transient performance. Also, a method to keep the virtual swing equation synchronised when the current saturates is presented. Remarkably, there is no need to change the controller structure during faults. Simulations of a PV inverter connected to a simple power system based on a diesel generator and loads are conducted. The results show that the proposed countermeasures improve the performance of GF-PV inverters in case of faults. In addition, it is shown that keeping the phase of the virtual swing equation and the grid voltage space vector synchronised is important to avoid the collapse of the dc-link voltage. Suggestions for further research are presented in the last part of the work.

2024

Work-in-progress—Introduction to Virtual Reality Headset: Experiments with Secondary and Higher Education students

Authors
Almeida, D; Castelhano, M; Morgado, L; Pedrosa, D;

Publication
Academic Proceedings of the 10th International Conference of the Immersive Learning Research Network (iLRN2024)

Abstract
This work-in-progress aims to analyze perspectives of secondary and higher education students regarding the feasibility of integrating immersive Virtual Reality (VR) into the classroom. The harvesting of students' opinions was conducted through oral and written questionnaires after a Virtual Reality Environment activity held during two sessions of an event and other in an undergraduate class. The answers enable the understanding of challenges they faced during the activity, identifying elements that contributed to participants' immersion, assessment of perceived realism, and individuals' opinions on the integration of VR in the classroom. Conclusions regarding the applicability of VR from the perspective of secondary and higher education students can be drawn.

2024

Program Synthesis using Inductive Logic Programming for the Abstraction and Reasoning Corpus

Authors
Rocha, FM; Dutra, I; Costa, VS;

Publication
CoRR

Abstract

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