79 documents found, page 1 of 8
A Drone Secure Handover Architecture validated in a Software in the Loop Enviro...
Vasconcelos Filho, Ênio; Gomes, Filipe; Monteiro, Stéphane; Penna, Sergio; Koubaa, Anis; Tovar, Eduardo; Severino, RicardoThe flight and control capabilities of uncrewed aerial vehicles (UAVs) have increased significantly with recent research for civilian and commercial applications. As a result, these devices are becoming capable of flying ever greater distances, accomplishing flights beyond line of sight (BVLOS). However, given the need for safety guarantees, these flights are increasingly subject to regulations. Handover operat...
Cooperative Vehicular Platooning: A Multi- Dimensional Survey Towards Enhanced ...
Vasconcelos Filho, Ênio; Santos, Pedro Miguel; Koubaa, Anis; Tovar, Eduardo; Severino, RicardoCooperative Vehicular Platooning (Co-VP) is a paradigmatic example of a Cooperative Cyber-Physical System (Co-CPS), which holds the potential to vastly improve road safety by partially removing humans from the driving task. However, the challenges are substantial, as the domain involves several topics, such as control theory, communications, vehicle dynamics, security, and traffic engineering, that must be coup...
A Farmácia do Futuro: perceção e contributos dos profissionais de farmácia
Dores, Artemisa Rocha; Peixoto, Miguel; Jesus, Ângelo; Moreira, Fernando; Gomes, Filipe; Monteiro, Stéphane; Severino, Ricardo; Marques, AntónioA utilização das tecnologias da informação e da comunicação (TIC), das tecnologias digitais e da inteligência artificial (IA) tem revolucionado a prestação de serviços na área da saúde, frequentemente designados por eHealth (Dores et al., 2020; Therapy 2.0). As Farmácias Comunitárias, beneficiando dos potenciais contributos destas tecnologias, podem agora oferecer novos serviços e em formatos inovadores, design...
The stability of complex dynamics for two families of coquaternionic quadratic ...
Falcão, M. I.; Miranda, Fernando; Severino, Ricardo; Soares, M. J.In this work, we begin by demonstrating that attractors, both periodic and aperiodic, of the one-parameter family of complex quadratic maps x2+ c, where c is a complex number, maintain their stability when we transition from the complex plane C to the coquaternions Hcoq as the map’s phase space. Next, we investigate the same question for a different family of quadratic maps, x2+ bx, and find that this is not th...
Dynamics of the coquaternionic maps x^2 + bx
Falcão, M. I.; Miranda, Fernando; Severino, Ricardo; Soares, M. J.This paper deals with the dynamics of the one-parameter family of coquaternionic quadratic maps x2+ bx. By making use of recent results for the zeros of one-sided coquaternionic polynomials, the fixed points are analytically determined. The stability of these fixed points is also addressed, where, in some cases, due to the appearance of sets of non-isolated points, a suitably adapted notion of stability is used...
A Two-step Quaternionic Root-finding Method
Falcão, M. I.; Miranda, Fernando; Severino, Ricardo; Soares, M. J.In this paper we present a new method for determining simultaneously all the simple roots of a quaternionic polynomial. The proposed algorithm is a two-step iterative Weierstrass-like method and has cubic order of convergence. We also illustrate a variation of the method which combines the new scheme with a recently proposed deflation procedure for the case of polynomials with spherical roots.
A Farmácia do Futuro: perceção e contributos dos profissionais de farmácia
R Dores, Artemisa; Peixoto, Miguel; Jesus, Angelo; Moreira, Fernando; Gomes, Filipe; Monteiro, Stéphane; Severino, Ricardo; Marques, AntónioIntrodução: A utilização das tecnologias da informação e da comunicação (TIC), das tecnologias digitais e da inteligência artificial (IA) tem revolucionado a prestação de serviços na área da saúde, frequentemente designados por eHealth (Dores et al., 2020; Therapy 2.0). As Farmácias Comunitárias, beneficiando dos potenciais contributos destas tecnologias, podem agora oferecer novos serviços e em formatos inovad...
Improving the Performance of Cooperative Platooning with Restricted Message Tri...
Vasconcelos Filho, Ênio; Santos, Pedro Miguel; Severino, Ricardo; Koubaa, Anis; Tovar, EduardoCooperative Vehicular Platooning (Co-VP) is one of the most prominent and challenging applications of Intelligent Traffic Systems. To support such vehicular communications, the ETSI ITS G5 standard specifies event-based communication profiles, triggered by kinematic parameters such as speed. The standard defines a set of threshold values for such triggers but no careful assessment in realistic platooning scenar...
Remarks on the zeros of quadratic coquaternionic polynomials
Falcão, M. I.; Miranda, Fernando; Severino, Ricardo; Soares, M. J.In this paper we focus on the study of monic quadratic polynomials whose coefficients are coquaternions and present several new results concerning the number and nature of its zeros. Examples specially constructed to illustrate the diversity of cases that can occur are also presented.
A modified quaternionic Weierstrass method
Falcão, M. I.; Miranda, Fernando; Severino, Ricardo; Soares, M. J.In this paper we focus on the study of monic polynomials whose coefficients are quaternions located on the left-hand side of the powers, by addressing three fundamental polynomial problems: factor, evaluate and deflate. An algorithm combining a deflaction procedure with a Weierstrass-like quaternionic method is presented. Several examples illustrate the proposed approach.