Smart cities and 6G are technological areas that have the potential to transform the way we live and work in the years to come. Until this transformation comes into place, there is the need, underlined by research and market studies, for a critical reassessment of the entire wireless communication sector for smart cities, which should include the IoT infrastructure, economic factors that could improve their adoption rate, and strategies that enable smart city operations. Therefore, from a technical point of view, a series of stringent issues, such as interoperability, data privacy, security, the digital divide, and implementation issues have to be addressed. Notably, to concentrate the scrutiny on smart cities and the forthcoming influence of 6G, the groundwork laid by the current 5G, with its multifaceted role and inherent limitations within the domain of smart cities, is embraced as a foundational standpoint. This examination culminates in a panoramic exposition, extending beyond the mere delineation of the 6G standard toward the unveiling of the extensive gamut of potential applications that this emergent standard promises to introduce to the smart cities arena. This paper provides an update on the SC ecosystem around the novel paradigm of 6G, aggregating a series of enabling technologies accompanied by the descriptions of their roles and specific employment schemes.

Driven by technological advances in various fields (AI, 5G, VR, IoT, etc.) together with the emergence of digital twins technologies (HDT, HAL, BIM, etc.), the Metaverse has attracted growing attention from scientific and industrial communities. This interest is due to its potential impact on people lives in different sectors such as education or medicine. Specific solutions can also increase inclusiveness of people with disabilities that are an impediment to a fulfilled life. However, security and privacy concerns remain the main obstacles to its development. Particularly, the data involved in the Metaverse can be comprehensive with enough granularity to build a highly detailed digital copy of the real world, including a Human Digital Twin of a person. Existing security countermeasures are largely ineffective and lack adaptability to the specific needs of Metaverse applications. Furthermore, the virtual worlds in a large-scale Metaverse can be highly varied in terms of hardware implementation, communication interfaces, and software, which poses huge interoperability difficulties. This paper aims to analyse the risks and opportunities associated with adopting digital replicas of humans (HDTs) within the Metaverse and the challenges related to managing digital identities in this context. By examining the current technological landscape, we identify several open technological challenges that currently limit the adoption of HDTs and the Metaverse. Additionally, this paper explores a range of promising technologies and methodologies to assess their suitability within the Metaverse context. Finally, two example scenarios are presented in the Medical and Education fields.

The rapid increase in Internet of Things (IoT) applications has raised security and privacy issues due to the huge amount of data acquired by IoT devices and transmitted through the Internet. Therefore, there is a need to understand what strategies should be applied to make IoT systems robust to security flaws and privacy weaknesses. In this paper, we first identify and discuss the best practices for IoT privacy and security, which include a set of procedures that can be taken as the guidelines to determine and solve privacy and security issues of IoT systems. Then, we follow and apply the identified best practices to two real IoT-based use cases: a crowding monitoring system and a vehicular mobility system. Finally, we computed the risk assessment score to evaluate the impact of the application of the identified best practices on the implemented IoT systems. We observe that following the proposed best practices the implemented IoT systems achieve an overall risk score of 1.3, which is from 215% to 361% lower than that achieved by comparable IoT systems proposed in the literature studies.

Dementia represents a global public health concern, with the early detection of Alzheimer's disease, the most prevalent form of dementia, being of paramount importance. Given the limited availability of suitable biomarkers, research has shown that early cognitive impairment can be identified through patients' spoken language. This paper presents a multi-modal system for automatic Alzheimer's disease detection using speech. The system has been trained on spoken recordings of healthy individuals and Alzheimer's patients describing an image, a task requiring linguistic and cognitive skills. Built on fine-tuned advanced Large Language Models, audio feature extractors, and classifiers, the system, after an extensive comparison of single and multi-modal architectures, achieves optimal results with the combination of Mistral-7B, VGGish, and Support Vector Classifier, outperforming previous methods on the ADReSSo 2021 test set.

In many fields, it is a common practice to collect large amounts of data characterized by a high number of features. These datasets are at the core of modern applications of supervised machine learning, where the goal is to create an automatic classifier for newly presented data. However, it is well known that the presence of irrelevant features in a dataset can make the learning phase harder and, most importantly, can lead to suboptimal classifiers. Consequently, it is becoming increasingly important to be able to select the right subset of features. Traditionally, optimization metaheuristics have been used with success in the task of feature selection. However, many of the approaches presented in the literature are not applicable to datasets with thousands of features because of the poor scalability of optimization algorithms. In this article, we address the problem using a cooperative coevolutionary approach based on differential evolution. In the proposed algorithm, parallelized for execution on shared-memory architectures, a suitable strategy for reducing the dimensionality of the search space and adjusting the population size during the optimization results in significant performance improvements. A numerical investigation on some high-dimensional and medium-dimensional datasets shows that, in most cases, the proposed approach can achieve higher classification performance than other state-of-the-art methods.