Repositório RCAAP

Na ausência de uma retaguarda familiar capaz de se constituir como uma fonte de segurança e apoio ao bem-estar e desenvolvimento integral de jovens com medida de promoção e proteção, o acolhimento residencial ganha maior importância, na medida em que permite promover e assegurar a proteção dos mesmos. Não obstante, a importância de um olhar cuidadoso sobre as variáveis de cariz estrutural, dão-nos pistas relevantes quanto a situações que poderiam ser melhoradas, com vista a proporcionar aos jovens acolhidos práticas mais securizantes, necessárias para quem na vida já se sentiu menos feliz e menos amado. Nesse sentido, e com vista a garantir um caminho centrado no seu projeto de vida que lhes garanta a autonomia e as competências necessárias para uma efetiva inserção social, torna-se crucial criar um ambiente propício ao pleno desenvolvimento físico e emocional dos jovens acolhidos, onde tenham figuras significativas que permitam colmatar a carência de compreensão, humanismo e acompanhamento que por vezes vivenciam. O presente Relatório integra um olhar atento e co construído relativo ao Projeto “(Re)Construir Vidas” orientado pela metodologia de Investigação Ação Participativa e que teve como finalidade “O desenvolvimento integral das jovens através da promoção da sua educação, saúde e bem-estar”. Para tal, investiu-se numa intervenção que potencializasse oportunidades de desenvolvimento moral, aprendizagem de interações mais adequadas e a construção de espaços que permitiram a descoberta de cada uma das jovens, potenciando a sua autoestima e segurança. Ainda que os resultados obtidos tenham sido considerados pertinentes e o Projeto tenha contribuído para condições que permitiram a educação, o bem-estar e o desenvolvimento integral das jovens, com o envolvimento dos profissionais, foi considerado que a continuidade da intervenção poderia alargar outros horizontes, proporcionando às jovens uma maior realização pessoal e social.

Neste trabalho são analisadas as ravinas de Seirós, localizadas próximo de Ribeira de Pena, no Norte de Portugal, e que, numa área agrícola, se instalaram sobre um coluvião. As ravinas formaram-se após um episódio de chuva intensa e concentrada, entre os dias 14 e 15 de dezembro de 2015. Este episódio chuvoso permitiu o galgamento de um canal, de geometria retangular, com cerca de 49 metros de comprimento, 0,70 metros de largura e 0,75 metros de profundidade, construído pelo proprietário do terreno agrícola como forma de proteção da escorrência proveniente de montante. Para além da caracterização e a análise dos factores que estiveram na génese das ravinas, este estudo também pretende discutir a adequação desta estratégia como forma de prevenção e mitigação do risco de ravinamento. Com base nos resultados obtidos pela simulação apresentada, torna-se claro que, para episódios de precipitação semelhantes o canal não é eficaz. Como medida mitigadora, sugere-se o aumento da profundidade da secção transversal do canal, cuja altura mínima recomendada deverá ser de 120 cm.

A acessibilidade da pessoa surda é cada vez mais premente na sociedade atual. Todo o conhecimento que a sociedade disponibiliza para esta comunidade irá influenciar as suas vivências e o seu conhecimento. Neste sentido, é urgente conhecer como a pessoa surda acede à informação que envolve o conceito de sexualidade. Deste modo, a presente investigação de cariz qualitativa surge com o intuito de conhecer a opinião da pessoa surda acerca da sexualidade. Para o efeito, recorreu-se à realização de grupos focais com um total de 18 participantes surdos. Assim, o estudo permitiu investigar as perceções que a pessoa surda tem relativamente ao conhecimento face à sexualidade, de que maneira foi obtido e quais as dificuldades enfrentadas na procura das informações pertinentes. Os resultados, apesar de poderem estar influenciados pelo estreito número da amostra do estudo, indicaram que a população surda tem a noção dos termos que englobam o conceito de sexualidade, na sua maioria. Mencionando como principais fontes de informação a escola, o médico e a família. Estes meios de informação estão influenciados por barreiras que impedem a acessibilidade da pessoa surda, como a falta de referentes gestuais, o conteúdo disponibilizado pela escola, ao abordar maioritariamente conteúdos biológicos, ou o médico e a família por não saberem LGP para comunicar. Salienta-se, no entanto, a importância da presença do intérprete, que segundo os participantes é fundamental para aceder à informação sobre a sexualidade em locais como o consultório médico ou a televisão, mas a sua presença não é efetiva o que acaba por degradar o acesso a determinados conteúdos sobre a temática.

Na bacia do rio Alva, à semelhança de outras áreas serranas do nosso território, algumas ravinas atingem uma dimensão espetacular. Neste trabalho procuramos analisar alguns fatores responsáveis pela evolução da ravina do Corgo, localizada no vale do rio Alva, no Centro de Portugal, nos últimos 4 anos (2015-2019), considerando o declive, a percentagem de coberto vegetal, a resistência do solo à penetração e torção, e a forma da vertente. Para o efeito, aplicou-se modelo de regressão múltipla (stepwise), ferramenta usada na construção de modelos para identificar um subconjunto útil de preditores. No período em análise, a ravina, com um comprimento de 130 metros, localizada sobre um manto de alteração granítico, teve um alargamento médio de 27.8 cm (DP: 72.0 cm) e um aprofundamento médio de 66 cm (DP: 85.5cm). Na evolução da ravina, o modelo de regressão explica entre 26% e 45 % do seu alargamento. Os resultados indicam 26% da variabilidade pela resistência do solo à penetração; 35,4% quando à variável anterior se associa o declive; e 44,5% quando se considera também a forma da vertente. Por sua vez, o aprofundamento assinalado pela ravina é explicado, entre 26% e 44,5%, a partir do mesmo modelo de regressão. A forma da vertente explica 32% da variância observada. Quando, além desta variável, se considera a percentagem de coberto vegetal, o resultado aumenta cerca de 10%. O modelo com o melhor resultado, 44,5%, considera as variáveis: forma da vertente, percentagem do coberto vegetal e resistência do solo à penetração. Confirmando os fatores envolvidos na evolução da ravina e optimizando a ligação estatística entre os fatores e a evolução, os resultados podem fornecer informações importantes para prever taxas de erosão em ambientes semelhantes.

This is the fourth volume of the successful series Robot Operating Systems: The Complete Reference, providing a comprehensive overview of robot operating systems (ROS), which is currently the main development framework for robotics applications, as well as the latest trends and contributed systems. The book is divided into four parts: Part 1 features two papers on navigation, discussing SLAM and path planning. Part 2 focuses on the integration of ROS into quadcopters and their control. Part 3 then discusses two emerging applications for robotics: cloud robotics, and video stabilization. Part 4 presents tools developed for ROS; the first is a practical alternative to the roslaunch system, and the second is related to penetration testing. This book is a valuable resource for ROS users and wanting to learn more about ROS capabilities and features.

A carefully designed routing synthesis can help system designers achieve a better load balancing in TSN-based networks and avoid congestion. To this end purpose, this work proposes two heuristics referred to as (1) LB-DRR, which aims at achieving a better load balancing and compute as much disjoint routing paths as possible for each replicated flow; and (2) CR-DRR, which recomputes paths for time-sensitive flows in congestion situations. Extensive simulations demonstrate that the proposed approach outperforms the classical Shortest Path (SPA) and the weighted Equal Cost Multi-path (wt-ECMP) algorithms in terms of the maximum load transmitted on a link by more than 70% and 20%, respectively.

Deterministic Synchronous Multichannel Extension (DSME) is a prominent MAC behavior first introduced in IEEE 802.15.4e supporting deterministic guarantees using its multisuperframe structure. DSME also facilitates techniques like multi-channel and Contention Access Period (CAP) reduction to increase the number of available guaranteed timeslots in a network. However, any tuning of these functionalities in dynamic scenarios is not explored in the standard. In this paper, we present a multisuperframe tuning technique called DynaMO which tunes the CAP reduction and Multisuperframe Order in an effective manner to improve flexibility and scalability, while guaranteeing bounded delay. We also provide simulations to prove that DynaMO with its dynamic tuning feature can offer up to 15-30% reduction in terms of latency in a large DSME network.

Deterministic Synchronous Multichannel Extension (DSME) is a prominent MAC behavior first introduced in IEEE 802.15.4e. It can avail deterministic and best effort Service using its multisuperframe structure. RPL is a routing protocol for wireless networks with low power consumption and generally susceptible to packet loss. These two standards were designed independently but with the common objective to satisfy the requirements of IoT devices in terms of limited energy, reliability and determinism. A combination of these two protocols can integrate real-time QoS demanding and largescale IoT networks. In this paper, we propose a new multi-channel, multi-timeslot scheduling algorithm called Symphony that provides QoS efficient schedules in DSME networks. In this paper we provide analytical and simulation based delay analysis for our approach against some state of the art algorithms. In this work, we show that integrating routing with DSME can improve reliability by 40 % and by using Symphony, we can reduce the network delay by 10-20% against the state of the art algorithms.

The increasing use of distributed generation units based on renewable energy sources, the consideration of demand-side management as a distributed resource, and the operation in the scope of competitive electricity markets have caused important changes in the way that power systems are operated. The new distributed resources require an entity (player) capable to make them able to participate in electricity markets. This entity has been known as Virtual Power Player (VPP). VPPs need to consider all the business opportunities available to their resources, considering all the relevant players, the market and/or other VPPs to accomplish their goals. This paper presents a methodology that considers all these opportunities to minimize the operation costs of a VPP. The method is applied to a distribution network managed by four independent VPPs with intensive use of distributed resources.

In a platoon-based vehicular cyber-physical system (PVCPS), a lead vehicle that is responsible for managing the platoon’s moving directions and velocity periodically disseminates control messages to the vehicles that follow. Securing wireless transmissions of the messages between the vehicles is critical for privacy and confidentiality of the platoon’s driving pattern. However, due to the broadcast nature of radio channels, the transmissions are vulnerable to eavesdropping. In this article, we propose a cooperative secret key agreement (CoopKey) scheme for encrypting/decrypting the control messages, where the vehicles in PVCPS generate a unified secret key based on the quantized fading channel randomness. Channel quantization intervals are optimized by dynamic programming to minimize the mismatch of keys. A platooning testbed is built with autonomous robotic vehicles, where a TelosB wireless node is used for onboard data processing and multihop dissemination. Extensive real-world experiments demonstrate that CoopKey achieves significantly low secret bit mismatch rate in a variety of settings. Moreover, the standard NIST test suite is employed to verify randomness of the generated keys, where the p-values of our CoopKey pass all the randomness tests. We also evaluate CoopKey with an extended platoon size via simulations to investigate the effect of system scalability on performance.

Vehicular ad-hoc networks (VANET) enable vehicles to exchange information on traffic conditions, dynamic status and localization, to enhance road safety and transportation efficiency. A typical VANET application is platooning, which can take advantage of exchanging information on speed, heading and position to allow shorter inter-vehicle distances without compromising safety. However, the platooning performance depends drastically on the quality of the communication channel, which in turn is highly influenced by the medium access control protocol (MAC). Currently, VANETs use the IEEE 802.11p MAC, which follows a carrier sense multiple access with collision avoidance (CSMA/CA) policy that is prone to collisions and degrades significantly with network load. This has led to recent proposals for a time-division multiple access (TDMA)-based MAC that synchronize vehicles’ beacons to prevent or reduce collisions. In this paper, we take CSMA/CA and two TDMA-based overlay protocols, i.e., deployed over CSMA/CA, namely PLEXE-slotted and RA-TDMAp, and carry out extensive simulations with varying platoon sizes, number of occupied lanes and transmit power to deduce empirical models that provide estimates of average number of collisions per second and average busy time ratio. In particular, we show that these estimates can be obtained from observing the number of radio-frequency (RF) neighbours, i.e., number of distinct sources of the packets received by each vehicle per time unit. These estimates can enhance the online adaptation of distributed applications, particularly platooning control, to varying conditions of the communication channel.

Industry 4.0 brings in a whole set of new requirements to engineering industrial systems, with notorious impact at the networking layer. A key challenge posed by Industry 4.0 is the operational flexibility needed to support on-the-fly reconfiguration of production cells, stations, and machines. At the networking layer, this flexibility implies dynamic packet handling, scheduling, and dispatching. SoftwareDefined Networking (SDN) provides this level of flexibility in the general Local Area Network (LAN) domain. However, its application in the industry has been hindered by a lack of support for real-time services. This paper addresses this limitation, proposing an extended SDN OpenFlow framework that includes realtime services, leveraging existing real-time data plane Ethernet technologies. We show the OpenFlow enhancements, a real-time SDN controller, and experimental validation and performance assessment. Using a proof-of-concept prototype with 3 switches and cycles of 250µs, we could achieve 1µs jitter on timetriggered traffic and a reconfiguration time between operational modes below 10ms

The increasing use of mobile cooperative robots in a variety of applications also implies an increasing research effort on cooperative strategies solutions, typically involving communications and control. For such research, simulation is a powerful tool to quickly test algorithms, allowing to do more exhaustive tests before implementation in a real application. However, the transition from an initial simulation environment to a real application may imply substantial rework if early implementation results do not match the ones obtained by simulation, meaning the simulation was not accurate enough. One way to improve accuracy is to incorporate network and control strategies in the same simulation and to use a systematic procedure to assess how different techniques perform. In this paper, we propose a set of procedures called Integrated Robotic and Network Simulation Method (IRoNS Method), which guide developers in building a simulation study for cooperative robots and communication networks applications. We exemplify the use of the improved methodology in a case-study of cooperative control comparison with and without message losses. This case is simulated with the OMNET++/INET framework, using a group of robots in a rendezvous task with topology control. The methodology led to more realistic simulations while improving the results presentation and analysis.

One thing can be said to be common to all forms of debit card fraud –authentication bypass. This implies that a secure debit card transaction system can only be guaranteed by a safe and reliable authentication system. Many approaches have been adopted to ensure a secure authentication system, but often, these approaches are either focused on the Automated Teller Machines (ATM)/Point of Sales (POS) terminals or Online/e-commerce transactions, thus not providing full security on both fronts. In this work, we address this problem by adopting a multi-factor debit card system that uses a combination of the traditional Personal Identification Number code (PIN) and the mobile-phone delivered One-Time Password (OTP) with a biometric authentication option(fingerprint). We demonstrate that this approach ensures the security of both online and terminal transactions. The fingerprint option makes it easy to use by people who find memorizing PINs difficult.

Recent advancements in the IoT domain have been pushing for stronger demands of Qualityof-Service (QoS) and in particular for improved determinism for time-critical wireless communications under power constraints. The IEEE 802.15.4e standard protocol introduced several new MAC behaviors that provide enhanced time-critical and reliable communications. The Deterministic Synchronous Multichannel Extension (DSME) is one of its prominent MAC behaviors that combines contention-based and contentionfree communication, guaranteeing bounded delays and improved reliability and scalability by leveraging multi-channel access and CAP reduction. However, DSME has a multi-superframe structure, which is statically defined at the beginning of the network. As the network evolves dynamically by changing its traffic characteristics, these static settings can affect the overall throughput and increase the network delay because of improper allocation of bandwidth. In this paper, we address this problem, and we present a dynamic multi-superframe tuning technique that dynamically adapts the multi-superframe structure based on the size of the network. This technique improves the QoS by providing 15-30% increase in throughput and 15-35% decrease in delay when compared to static DSME networks

Unmanned Aerial Vehicles (UAVs) with Microwave Power Transfer (MPT) capability provide a practical means to deploy a large number of wireless powered sensing devices into areas with no access to persistent power supplies. The UAV can charge the sensing devices remotely and harvest their data. A key challenge is online MPT and data collection in the presence of on-board control of a UAV (e.g., patrolling velocity) for preventing battery drainage and data queue overflow of the devices, while up-to-date knowledge on battery level and data queue of the devices is not available at the UAV. In this paper, an on-board deep Q-network is developed to minimize the overall data packet loss of the sensing devices, by optimally deciding the device to be charged and interrogated for data collection, and the instantaneous patrolling velocity of the UAV. Specifically, we formulate a Markov Decision Process (MDP) with the states of battery level and data queue length of devices, channel conditions, and waypoints given the trajectory of the UAV; and solve it optimally with Q-learning. Furthermore, we propose the on-board deep Q-network that enlarges the state space of the MDP, and a deep reinforcement learning based scheduling algorithm that asymptotically derives the optimal solution online, even when the UAV has only outdated knowledge on the MDP states. Numerical results demonstrate that our deep reinforcement learning algorithm reduces the packet loss by at least 69.2%, as compared to existing non-learning greedy algorithms.

Unmanned Aerial Vehicles are increasingly being used in surveillance and traffic monitoring thanks to their high mobility and ability to cover areas at different altitudes and locations. One of the major challenges is to use aerial images to accurately detect cars and count-them in real-time for traffic monitoring purposes. Several deep learning techniques were recently proposed based on convolution neural network (CNN) for real-time classification and recognition in computer vision. However, their performance depends on the scenarios where they are used. In this paper, we investigate the performance of two state-of-the art CNN algorithms, namely Faster R-CNN and YOLOv3, in the context of car detection from aerial images. We trained and tested these two models on a large car dataset taken from UAVs. We demonstrated in this paper that YOLOv3 outperforms Faster R-CNN in sensitivity and processing time, although they are comparable in the precision metric.

The following topics are dealt with: mobile robots; multi-robot systems; path planning; robot vision; service robots; collision avoidance; learning (artificial intelligence); legged locomotion; control engineering computing; production engineering computing.

Building and maintaining complex systems requires good software engineering practices, including code modularity and reuse. The same applies in the context of coordination of complex component-based systems. This paper investigates how to verify properties of complex coordination patterns built hierarchically, i.e., built from composing blocks that are in turn built from smaller blocks. Most existing approaches to verify properties flatten these hierarchical models before the verification process, losing the hierarchical structure. We propose an approach to verify hierarchical models using containers as actions; more concretely, containers interacting with their neighbours. We present a dynamic modal logic tailored for hierarchical connectors, using Reo and Petri Nets to illustrate our approach. We realise our approach via a prototype implementation available online to verify hierarchical Reo connectors, encoding connectors and formulas into mCRL2 specifications and formulas

The commodity Single Board Computers (SBCs) are increasingly becoming powerful and can execute standard operating systems and mainstream workloads. In the context of cloud-based smart city applications, SBCs can be utilized as Edge computing devices reducing the network communication. In this paper, we investigate the design and implementation of a SBC based edge cluster (SBC-EC) framework for a smart parking application. Since SBCs are resource constrained devices, we devise a container based framework for a lighter foot-print. Kubernetes was used as an orchestration tool to orchestrate various containers in the framework. To validate our approach, we implemented a proof-of-concept of the SBC based Edge cluster for a smart parking application, as a possible ioT use-case.Our implementation shows that, the use of SBC devices at the edge of a cloud based smart parking application is a cost effective and low energy, green computing solution. The proposed framework can be extended to similar cloud based applications in the context of a smart city.