Abstract
In the last few decades, there has been a growing interest in exploring the sea. The activities of the so-called blue economy can go from applications such as offshore maritime wind farms to ocean environment monitoring, which are supported by sensed platforms such Autonomous Surface Vehicles (ASVs) and Autonomous Underwater Vehicles (AUVs) that require the use of reliable underwater communications. Currently, there is no suitable solution that is able to combine long-range and broadband underwater communications. The integration of different technologies, namely acoustics, RF, and optical on a multimodal approach, has been considered a suitable solution to overcome the limitations caused by the water propagation medium. Since missions at the ocean are usually expensive and demand large human and technological resources, it is important to have accurate simulation platforms for these multimodal underwater wireless networks. This paper presents the first version of a novel simulation framework - MultiUWSim (Beta) -, built upon ns-3, which integrates multiple communications technologies (RF, acoustics and optical). The current version of the simulation platform offers the possibility of simulating acoustic-based and radio-based physical wireless interfaces in a single node in a ns-3 simulation environment, enabling fully-customizable underwater network simulations.

Abstract

Abstract
Since the emergence of the Triple Helix, expansions to Quadruple, Quintuple, N-tuple helices, and models decomposing higher-order helices into multiple interrelated triple helices, or two-layer triple helices have been proposed. Albeit presenting alternative conceptual frameworks these different Helix models seem unsuited to address internal boundaries to the institutional spheres of the university, industry, and government. Addressing this circumstance, the present article pursues the research purpose of conceptualizing a perspective that opens the possibility of analysis to occur between but also within the boundaries of the institutional spheres. To that effect it advocates the application of different reference frames (scopes) to capture the dynamics that empirically emerge from the system under research. The novelty of this study is that it expands the existing theory by proposing that adding “scopes” (instead of introducing new helices) can increase the analytical potential of the Triple Helix. © Pedro Costa Simões et al., 2022.

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Abstract
This study proposes a benchmarking approach to assess water supply and sanitation services' performance in Brazilian municipalities from an integrated perspective of efficiency and access. The regional differences and the impact of the governance models adopted by different municipalities (local public entities, regional public entities, and private entities) on efficiency levels are also explored. The results revealed significant heterogeneity in the efficiency levels of Brazilian municipalities, as the average efficiency score is relatively low (45%). The Southeast and Center-west regions stand out both in terms of efficiency and access dimensions. There is evidence that municipalities with services provided by local public entities have higher efficiency than those with regional providers. On the other hand, efficiency differences between municipalities with public and private providers are statistically significant. Finally, regulatory strategies are suggested based on the outcome of the integrated analysis.

Abstract
Considering the growing volume of information and services available on the web, it has become essential to provide websites and applications with tools, such as recommender systems, capable of helping users to obtain the information and services appropriate to their interests. Due to the complexity of web adaptation and the ability of multi-agent systems to deal with complex problems, the use of multi-agent approaches in recommender systems has been increasing. In the present work, we make a thorough review of the use of multi-agent-based recommender systems. The review shows the diversity of applications of multi-agent systems in recommender systems, namely on what concerns the diversity of domains, different types of approaches and contribution to the performance improvement of the recommender systems.