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- Convergence of the Reinforcement Learning Mechanism Applied to the Channel Detection Sequence ProblemPublication . Mendes, Andre C.The use of mechanisms based on artificial intelligence techniques to perform dynamic learning has received much attention recently and has been applied in solving many problems. However, the convergence analysis of these mechanisms does not always receive the same attention. In this paper, the convergence of the mechanism using reinforcement learning to determine the channel detection sequence in a multi-channel, multi-user radio network is discussed and, through simulations, recommendations are presented for the proper choice of the learning parameter set to improve the overall reward. Then, applying the related set of parameters to the problem, the mechanism is compared to other intuitive sorting mechanisms.
- Learning emergent digital technologies: the experience in the internet of things course unitPublication . Leitão, Paulo; Piardi, Luis; Sakurada, Lucas; Mendes, Andre C.Industry 4.0 is re-shaping the way companies and individuals operate, but it is also introducing strong demands in education processes to train professionals with adequate competencies in emergent digital technologies, e.g., Internet of Things (IoT), Artificial Intelligence and collaborative robotics. In the last decade, innovative educational methods are being applied, e.g., problem-based learning and project-based learning, to move the traditional education approach into a more student-centric process where the student has a more active role. Recent studies point out that the combination of such educational methods is beneficial, each one selected according to the particularities of the learning subject and objective. Having this in mind, this paper describes the application of a learning methodology that combines different educational methods, namely face-toface, problem-based learning and project-based learning, in a teaching course unit focusing on IoT technologies. The achieved results show an increase of the student’s assessment performance, motivation and satisfaction, and the opportunity to consolidate their acquired knowledge with hands-on practice. This approach also stimulates the acquisition of soft skills, mainly teamwork, communication, creativity and critical thinking.
- Integration of ROS navigation stack with dynamic environment information in gazebo simulationPublication . Mendes, Pedro Henrique Ferreira; Mendes, Andre C.; Duarte, Luis F.C.Sensing the environment is a crucial task that robots have to perform to navigate autonomously. Furthermore, it must be well executed to make navigation safer and collision-free. As autonomous mobile robots are being deployed in several applications, they often encounter dynamic habitats, where sensing and perceiving the environment becomes harder. This work proposes integrating a wireless sensor network with the Robotic Operating System to incorporate data into layered costmaps used by the robot to navigate, feeding the algorithms with advanced information about the territory. The architecture was tested in simulation, where we could validate the structure and collect data showing improved paths calculated and reduced computational load through better parametrization. Thus, this strategy ensures that the advanced information about the environment has improved the navigation process.
- Management of virtual environments with emphasis on securityPublication . Mendes, Andre C.With the popularity of using virtual environments, it urges important measures that increase its security, as well as maintain a good user experience. A widespread attack is a denial of service which proposes to break the availability of service through a large number of illegitimate requests employing all computing resources of the target and degrading the user experience. In order to be effective in this particular type of attack, usually powerful equipment or a combination of them is required. This article proposes a new approach to this attack through a languagebased Erlang application, which uses the processing power of a low-cost device. Its use would open the possibility of effective attacks coming from devices with less processing power, or from IoT devices, but capable of at least degrading the experience of a legitimate user, anonymously.
- IoT-based solution to reduce waste and promote a sustainable farming industryPublication . Stefanuto, Bruno; Funchal, Gustavo Silva; Melo, Victoria; Mendes, Andre C.; Raimundo, Délio; Gouveia, Hélia; Coelho, João Paulo; Leitão, PauloWaste and the necessity to increase sustainability in the farming industry are some of the challenges addressed in the agri-food chain. With the potential of digital technologies, e.g., the Internet of Things (IoT) and Artificial Intelligence, to revolutionize agriculture by enabling more efficient and intelligent monitoring, system architecture and IoT nodes were developed to support relevant parameters for composing a Sustainability Index for the Bio-economy (siBIO). These nodes are scalable, modular, capable of meeting on-demand production needs, and provide a cost-effective alternative to commercial solutions or manual data collection methods. The collected data is transmitted to middleware and then stored, analyzed, and displayed on a user-friendly dashboard, providing data to siBIO and consequently contributing to a more sustainable farming industry and reducing waste of resources and food. The results include the implementation of IoT nodes in a case study involving a vineyard and an apple orchard. The nodes are successfully collecting data on environmental, operational, and energy parameters such as temperature, air humidity, soil moisture, precipitation, and water and electricity consumption for irrigation. The tests of data transmission and collection, functionality and robustness of the proposed solution were promising, offering a way to quantify the sustainability index and facilitate the exchange of agricultural information in a reliable and standardized way.
- Indoor location estimation based on diffused beacon networkPublication . Mendes, Andre C.; Diaz-Cacho, MiguelThis work investigates the problem of location estimation in indoor Wireless Sensor Networks (WSN) where precise, discrete and low-cost independent self-location is a critical requirement. The indoor scenario makes explicit measurements based on specialised location hardware, such as the Global Navigation Satellite System (GNSS), difficult and not practical, because RF signals are subjected to many propagation issues (reflections, absorption, etc.). In this paper, we propose a low-cost effective WSN location solution. Its design uses received signal strength for ranging, lightweight distributed algorithms for location computation, and the collaborative approach to delivering accurate location estimations with a low number of nodes in predefined locations. Through real experiments, our proposal was evaluated and its performance compared with other related mechanisms from literature, which shows its suitability and its lower average location error almost of the time.
- Analysis of topological characteristics impacting the allocation of controllers in an SD-WAN networkPublication . Padrenuestro, Vicente; Mendes, Andre C.Finding a viable and optimal solution to the Software-Defined Networks (SDN) controller allocation problem in an open SDN network is a challenging task. In this context, this work was developed to expose a network's real characteristics, which may impact the choice of positioning an SDN controller. Furthermore, the experiments with the Pareto-based Optimal Controller-placement (POCO) tool and with the ONOS and Floodlight controllers are shown, which served as a comparison to assist in decision-making regarding the best positioning of the controller within the network. In summary, the results showed that not only the static aspects of the network should be considered, but also the dynamic characteristics and aspects related to the model and the purpose for which the controllers are used, factors that can impact the positioning.
- Real cockpit proposal for flight simulation with airbus A32x models: an overview descriptionPublication . Carvalho, José Augusto; Mendes, Andre C.; Brito, Thadeu; Lima, JoséThis paper describes the several steps to build an elaborate flight simulator cockpit, where the hardware is designed based on Mechatronic principles and the proposed software was developed using agile methodologies to create a Cyber-Physical System (CPS). Furthermore, this research attempts to simulate the real environment from an aircraft as close as possible with a real scale developed cockpit. Based on this, the presented paper contributions include: (1) The implementation of a complex dynamic system such as a CPS, where the Mechatronic system is part of it; (2) The deployment of a scale model of an Airbus A32x aircraft (one of the most used), integrating into a mathematical model adapted to the operation of an aircraft flight simulation system, regarding the physical forces involved. This project is also used to captivate the students’ motivation to the areas of technology such as electronics and programming and permits its development as a student project and thesis. Results allow validating the proposed cockpit.
- Real airplane cockpit development applied to engineering education: a project based learning approachPublication . Carvalho, José Augusto; Mendes, Andre C.; Brito, Thadeu; Lima, JoséEngineering education, the process of teaching knowledge and principles to the professional practice of engineering, can be done by resorting to several methodologies. Project Based Learning is a teaching method that allows students to get knowledge and skills by developing and solving complex problems or challenges, supported by a supervisor. In the presented work, a real airplane cockpit development is used as a case study for Mechanical, Mechatronics, Electrical, and Computer Science courses. Students are encouraged to develop modules to be applied in the cockpit and further integrated with other ones.
- Cooperative awareness in cognitive wireless networks for jamming controlPublication . Mendes, Andre C.; Brandão, Diego; Diaz-Cacho, MiguelIn cognitive wireless networks, opportunistic network devices can be programmed to take advantage of licence holders' idle times and dynamically adjust their operating parameters to improve transmissions. For this to be successful, these idle periods must be reliably detected. To support this requirement, this work proposes a cooperative detection mechanism for the signals transmitted by the licenced system through the use of positioning-enabled devices. Such devices can provide information to guide and control opportunistic network devices to limit interference to the licenced system. Simulations show that keeping interference within specification limits makes it possible to maintain opportunistic network communications in an ad hoc scenario with quality.