Abstract
We consider the problem of multi agents cooperating in a partially-observable environment. Agents must learn to coordinate and share relevant information to solve the tasks successfully. This article describes Asynchronous Advantage Actor-Critic with Communication (A3C2), an end-to-end differentiable approach where agents learn policies and communication protocols simultaneously. A3C2 uses a centralized learning, distributed execution paradigm, supports independent agents, dynamic team sizes, partially-observable environments, and noisy communications. We compare and show that A3C2 outperforms other state-of-the-art proposals in multiple environments.

Abstract
Millions of people use public transport on a daily basis. Although most public transport systems use traditional ticketing approaches, based on tickets and smartcards, there are already ticketing alternatives based on smartphones. Most of the mobile ticketing solutions developed and available in the market use technologies such as Near Field Communication (NFC) or Quick Response Codes (QR Codes), and there are practically no studies on the use of Bluetooth Low Energy (BLE) for this purpose. This paper focuses on assessing the feasibility of using BLE beacons for mobile ticketing in urban passenger transport. The study was conducted during the development of a mobile ticketing solution for the Metropolitan Area of Porto (AMP) that takes advantage of the Bluetooth technology present on the passengers' smartphones. It uses BLE beacons to track the passengers' trips from the start to the end, as part of an implementation of a check-in/be-out system. This solution was implemented as a prototype to be tested in the AMP and all the tests performed were made during the course of a pilot test of this prototype. The study consisted of a set of technical tests related with beacons signal monitoring and the gathering and analysis of passengers' feedback who participated in a four months pilot test. The results obtained suggest that the BLE technology is feasible for mobile ticketing in urban passenger transport. The paper also presents the various available deployment alternatives, identifies the main problems found and proposes solutions to solve them, filling an important research gap in the literature. © 2020 The Authors

Abstract
This paper showcases how the Contract Agency Model can be used to uncover literacy practices in videogame’s own terms as a complement to existing, more ‘indirect’ games literacies, using as an example the videogame Total War: Shogun 2. The paper first situates the Contract Agency Model within approaches to videogames and within approaches to media literacy. The paper then identifies three interesting literacy practices in the videogame, which also exemplify the eight levels of abstraction of the Contract Agency Model. The paper concludes by discussing the model’s implications to media literacy and videogames, namely that videogames effect a second-order mutual signaling with their players – agency as a conversation of commitment to meaning – that is humanizing of those players, and that the model can uncover this as an im-plicit contract of bio-costs, as a ‘direct’ literacy of videogames, i.e. a literacy in videogames’ own terms. © 2020 BY-NC-ND.

Abstract
Besides the large amount of traffic that radio access and backhaul networks need to accommodate, the interest in low-latency communications is emerging. The goal is to reliably transmit high bitrates through the network under controlled delays, thus enabling human and machine-oriented communications. A critical aspect that must be addressed is the latency introduced by network queues. The literature has been focused on studying the queue size in wired networks, but wireless networks bring up additional challenges due to their dynamic characteristics. The problem is exacerbated in high dynamic networks, such as Flying Networks (FNs) composed of Unmanned Aerial Vehicles (UAVs), which have emerged to provide communications anywhere, anytime. The main contribution of this paper is a Proactive Queue Management (PQM) solution for FNs with controlled topology. PQM takes advantage of the knowledge of the future FN topologies and the offered traffic to define in advance the queue size of the communications nodes over time, in order to maximize the throughput with stochastic delay guarantees. The FN performance achieved using PQM is evaluated by means of ns-3 simulations, showing gains regarding aggregate throughput and average delay.

Abstract
Virtual power plants (VPPs) are defined as an aggregator of different types of energy resources and flexibility, coordinated by VPP owner through a smart control system. A correct establishment of a VPP will result in reduced electricity costs for the consumers within the VPP. One of the key aspect of VPP's success is the consumer engagement in order to manage their flexibilities effectively. Gamification is an efficient way of learning and engagement, which can efficiently change the behavior of consumers towards participating in programs provided by VPPs for energy cost reduction. In this paper, a gamification-based approach for consumer engagement is proposed and a methodology based on Fogg's behavior model and Kim's model on player types is developed to examine the suitability of available gamification applications for energy saving/efficiency in the context of a VPP. Seven gamification applications are analyzed and evaluated based on the developed methodology and the results are provided. © 2020 IEEE.

Abstract
Intelligent wheelchairs allow individuals to move more freely, safely, and facilitate users’ interaction with the wheelchair. This paper presents the results focused on the study and analysis of the state of the art related to topics as interaction, interfaces, intelligent wheelchairs and the analysis of the Intellweelsproject. The main goal is to create and implement a multimodal adaptive interface to be used as the control and interaction module of an intelligent wheelchair. Moreover, it will be important to have in mind the usability, by facilitating the control of a complex system, interactivity, by allowing the control using diverse kinds of input devices, and expansibility, by integrating easily with several intelligent external systems. This project features a complex input/output system with linked parameters simplified by a node system to create the input/output actions with automatic input recording and intuitive output association as well as a powerful, device-agnostic design, providing an easy way to extend the inputs, outputs and event the user interface. Results reveal a positive users’ feedback and a responsive way when using the multimodal interface in simulated environment. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020.