Abstract
Resumo:Com este estudo apresenta-se uma nova perspectiva tridimensional do Castelo Velho de Safara (Moura), um dos grandes povoados muralhados da Idade do Ferro/período Romano Republicano existentes na linha do Rio Guadiana, criada a partir de um levantamento de alta resolução realizado com sensor LiDAR acoplado a um drone. O resultado obtido permitiu a definição detalhada da planta da muralha, o que implicou a revisão da superfície de ocupação, que agora é estimada em cerca de 1.36 hectares. Foram também identificados vários elementos inéditos, como a zona da entrada e eventuais soluções de reforço defensivo. Os dados obtidos para o Castelo Velho de Safara demonstram o potencial dos dados LiDAR para o reconhecimento das características topográficas deste tipo de recintos fortificados, cuja visibilidade das estruturas nem sempre é possível a olho nu.Palavras-chave: Idade do Ferro; Período Romano Republicano; Estruturas defensivas; Drone; LiDAR.   Abstract:This study presents a new tridimensional perspective on Castelo Velho de Safara (Moura), one of the great walled settlements of the Iron Age/Roman Republic by the Guadiana River, obtained through a high-resolution survey using a drone integrated with a LiDAR sensor. The outline of the walls was defined in more detail, which meant revising the occupation area, now estimated at circa 1.36 hectares. Several unknown elements were detected, such as the entrance area and other possible defensive structures. The data obtained for the Castelo Velho de Safara demonstrate the potential of LiDAR for understanding the topographical characteristics of this type of fortified enclosure, whose structural remains are not always clear to the naked eye.Keywords: Iron Age; Roman Republic; Defensive structures; Drone; LiDAR; Odyssey.

Abstract
Stress-ribbon footbridges are often prone to excessive vibrations induced by environmental phenomena (e.g., wind) and human actions (e.g., walking). This paper studies a stress-ribbon footbridge at the Faculty of Engineering of the University of Porto (FEUP) in Portugal, where different degrees of vertical vibrations are perceptible in response to human actions. We adopt sonification techniques to create a sonic manifestation that shows the footbridge’s dynamic response to human interaction. Two distinct sonification techniques – audification and parameter mapping – are adopted to provide intuitive access to the footbridge dynamics from low-level acceleration data and higher-level spectral analysis. In order to evaluate the proposed sonification techniques in exposing relevant information about human actions on the footbridge, an online perceptual test was conducted to assess the understanding of the three following dimensions: 1) the number of people interacting with the footbridge, 2) their walking speed, and 3) the steadiness of their pace. The online perceptual test was conducted with and without a short training phase. Results of n= 23 participants show that parameter mapping sonification is more effective in promoting an intuitive understating of the footbridge dynamics compared to audification. Furthermore, when exposed to a short training phase, the participants’ perception improved in identifying the correct dimensions. © 2023, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

Abstract

Abstract
Medical imaging, mainly Magnetic Resonance Imaging (MRI), plays a predominant role in healthcare diagnosis. Nevertheless, the diagnostic process is prone to errors and is conditioned by available medical data, which might be insufficient. A novel solution is resorting to image generation algorithms to address these challenges. Thus, this paper presents a Deep Learning model based on a Deep Convolutional Generative Adversarial Network (DCGAN) architecture. Our model generates 2D MRI images of size 256x256, containing an axial view of the brain with a tumor. The model was implemented using ChainerMN, a scalable and flexible framework that enables faster and parallel training of Deep Learning networks. The images obtained provide an overall representation of the brain structure and the tumoral area and show considerable brain-tumor separation. For this purpose, and owing to their previous state-of-the-art results in general image-generation tasks, we conclude that GAN-based models are a promising approach for medical imaging.

Abstract
In recent years, the EU has been pushing forward ground-breaking legislation that covers new digital environments and services, with a strong focus on Ethics and AI. This includes legislation such as the Artificial Intelligence Act, the Digital Services Act or the General Data Protection Regulation. This legislation is, however, often written in very general and high-level terms, leaving a lot of space for interpretation, and a gap concerning how it could or should be implemented, realistically. In this paper we look specifically at the principle of Transparency in the Digital Services Act. Specifically, we discuss the requirements concerning Transparency in the regulation, we identify the gaps, and propose concrete measures that can be considered to facilitate and guide its implementation.

Abstract
PurposeNon-profit organizations (NPO) contribute significantly to the welfare of citizens and communities. Engagement in volunteering is crucial for sustaining volunteer motivation and for the effective and efficient functioning of NPO, with significant implications for society at large. Yet, literature on volunteer engagement (VE) is limited to date. Grounded on service-dominant logic, self-congruity theory and self-determination theory, this study aims to understand what motivates VE and how it may evolve into a co-creation process valuable to NPO and its stakeholders.Design/methodology/approachBased on survey data collected from 450 volunteers, working with a diverse set of NPO, a comprehensive model of drivers and outcomes of VE was empirically tested using PLS-SEM, considering the mediating role of volunteers' congruence with the core values of the NPO.FindingsThe impact of volunteers' perceived autonomy, competence and relatedness on VE and its subsequent role in volunteers' loyalty and extra-role engagement behaviors (i.e. co-development, influencing and mobilizing behaviors) were validated. Moreover, the study validates value congruence as an internalizing mediating mechanism in the engagement process, a role that has been implied but not empirically tested.Originality/valueThe study contributes to the engagement and volunteering literature, which despite an unprecedented parallel have developed almost independently, with limited reference to one another. As the nomological network of VE is still underexplored, the study extends the engagement literature to the volunteering sector, validating the key (but underexplored) role of self-determination needs and value congruence in driving VE and value co-creation behaviors. The study further adds to engagement research while addressing other actors' engagement beyond the customer-brand dyad. While adopting a seldom explored marketing perspective of VE, this study provides NPO valuable insights on how to manage and engage volunteers.