ZAP – Muito mais que um acesso privilegiado

Parafraseando as prescrições e especificações técnicas da 2ª Edição do Manual de Infraestruturas de Telecomunicações em Edifícios (ITED), “Os fogos de uso residencial possuem, obrigatoriamente, um local onde se concentram as três tecnologias: par de cobre (PC), cabo coaxial (CC) e fibra ótica (FO). Esse local é designado por Zona de Acesso Privilegiado (ZAP) e localiza‐se na divisão mais adequada, no entendimento do projetista e de acordo com as preferências do dono de obra“. Nesta zona concentram‐se as 3 tecnologias atualmente obrigatórias constituindo, assim, um suporte para o fornecimento avançado de serviços tecnológicos evoluídos. A modernização e evolução das infraestruturas de comunicações eletrónicas em Portugal na última década, quer ao nível regulatório, quer ao nível tecnológico dos equipamentos, constituem, implacavelmente, um poderoso incentivo à expansão da sociedade do conhecimento que deixaremos como legado às gerações vindouras

Sustainable Approach to Weed Management: The Role of Precision Weed Management

In the last few decades, the increase in the world’s population has created a need to produce more food, generating, consequently, greater pressure on agricultural production. In addition, problems related to climate change, water scarcity or decreasing amounts of arable land have serious implications for farming sustainability. Weeds can affect food production in agricultural systems, decreasing the product quality and productivity due to the competition for natural resources. On the other hand, weeds can also be considered to be valuable indicators of biodiversity because of their role in providing ecosystem services. In this sense, there is a need to carry out an effective and sustainable weed management process, integrating the various control methods (i.e., cultural, mechanical and chemical) in a harmonious way, without harming the entire agrarian ecosystem. Thus, intensive mechanization and herbicide use should be avoided. Herbicide resistance in some weed biotypes is a major concern today and must be tackled. On the other hand, the recent development of weed control technologies can promote higher levels of food production, lower the amount of inputs needed and reduce environmental damage, invariably bringing us closer to more sustainable agricultural systems. In this paper, we review the most common conventional and non-conventional weed control strategies from a sustainability perspective, highlighting the application of the precision and automated weed control technologies associated with precision weed management (PWM).info:eu-repo/semantics/publishedVersio

Powerless sensor for non-intrusive multi-fiber traffic monitoring

The rapid expansion of fiber optic networks and services, which sees a large number of circuits enabled and disabled each day, introduces a significant complexity for operators to identify fibers that have and do not have attached clients. The service level agreements prevent operators from disconnecting circuits without absolute assurance that no clients are attached. We propose a non-intrusive multichannel fiber detector to facilitate the operation and maintenance of the optical networks. The optical distribution frame usually does not have any power available, thus, the proposed device operates without batteries and is powered by near field communication (NFC). Device installation does not require fiber disconnection or communication interruption, and introduces less than 1 dB insertion loss to detect optical signals down to -30 dBm. In order to read multiple fiber channel status, an NFC-enabled smartphone is used to power the device and measure the signal levels of each channel.info:eu-repo/semantics/publishedVersio

Autonomous Obstacle Collision Avoidance System for UAVs in rescue operations

The Unmanned Aerial Vehicles (UAV) and its applications are growing for both civilian and military purposes. The operability of an UAV proved that some tasks and operations can be done easily and at a good cost-efficiency ratio. Nowadays, an UAV can perform autonomous tasks, by using waypoint mission navigation using a GPS sensor. These autonomous tasks are also called missions. It is very useful to certain UAV applications, such as meteorology, vigilance systems, agriculture, environment mapping and search and rescue operations. One of the biggest problems that an UAV faces is the possibility of collision with other objects in the flight area. This can cause damage to surrounding area structures, humans or the UAV itself. To avoid this, an algorithm was developed and implemented in order to prevent UAV collision with other objects. “Sense and Avoid” algorithm was developed as a system for UAVs to avoid objects in collision course. This algorithm uses a laser distance sensor called LiDAR (Light Detection and Ranging), to detect objects facing the UAV in mid-flights. This light sensor is connected to an on-board hardware, Pixhawk’s flight controller, which interfaces its communications with another hardware: Raspberry Pi. Communications between Ground Control Station or RC controller are made via Wi-Fi telemetry or Radio telemetry. “Sense and Avoid” algorithm has two different modes: “Brake” and “Avoid and Continue”. These modes operate in different controlling methods. “Brake” mode is used to prevent UAV collisions with objects when controlled by a human operator that is using a RC controller. “Avoid and Continue” mode works on UAV’s autonomous modes, avoiding collision with objects in sight and proceeding with the ongoing mission. In this dissertation, some tests were made in order to evaluate the “Sense and Avoid” algorithm’s overall performance. These tests were done in two different environments: A 3D simulated environment and a real outdoor environment. Both modes worked successfully on a simulated 3D environment, and “Brake” mode on a real outdoor, proving its concepts.Os veículos aéreos não tripulados (UAV) e as suas aplicações estão cada vez mais a ser utilizadas para fins civis e militares. A operacionalidade de um UAV provou que algumas tarefas e operações podem ser feitas facilmente e com uma boa relação de custo-benefício. Hoje em dia, um UAV pode executar tarefas autonomamente, usando navegação por waypoints e um sensor de GPS. Essas tarefas autónomas também são designadas de missões. As missões autónomas poderão ser usadas para diversos propósitos, tais como na meteorologia, sistemas de vigilância, agricultura, mapeamento de áreas e operações de busca e salvamento. Um dos maiores problemas que um UAV enfrenta é a possibilidade de colisão com outros objetos na área, podendo causar danos às estruturas envolventes, aos seres humanos ou ao próprio UAV. Para evitar tais ocorrências, foi desenvolvido e implementado um algoritmo para evitar a colisão de um UAV com outros objetos. O algoritmo "Sense and Avoid" foi desenvolvido como um sistema para UAVs de modo a evitar objetos em rota de colisão. Este algoritmo utiliza um sensor de distância a laser chamado LiDAR (Light Detection and Ranging), para detetar objetos que estão em frente do UAV. Este sensor é ligado a um hardware de bordo, a controladora de voo Pixhawk, que realiza as suas comunicações com outro hardware complementar: o Raspberry Pi. As comunicações entre a estação de controlo ou o operador de comando RC são feitas via telemetria Wi-Fi ou telemetria por rádio. O algoritmo "Sense and Avoid" tem dois modos diferentes: o modo "Brake" e modo "Avoid and Continue". Estes modos operam em diferentes métodos de controlo do UAV. O modo "Brake" é usado para evitar colisões com objetos quando controlado via controlador RC por um operador humano. O modo "Avoid and Continue" funciona nos modos de voo autónomos do UAV, evitando colisões com objetos à vista e prosseguindo com a missão em curso. Nesta dissertação, alguns testes foram realizados para avaliar o desempenho geral do algoritmo "Sense and Avoid". Estes testes foram realizados em dois ambientes diferentes: um ambiente de simulação em 3D e um ambiente ao ar livre. Ambos os modos obtiveram funcionaram com sucesso no ambiente de simulação 3D e o mode “Brake” no ambiente real, provando os seus conceitos

Sustainable Approach to Weed Management: The Role of Precision Weed Management

In the last few decades, the increase in the world’s population has created a need to produce more food, generating, consequently, greater pressure on agricultural production. In addition, problems related to climate change, water scarcity or decreasing amounts of arable land have serious implications for farming sustainability. Weeds can affect food production in agricultural systems, decreasing the product quality and productivity due to the competition for natural resources. On the other hand, weeds can also be considered to be valuable indicators of biodiversity because of their role in providing ecosystem services. In this sense, there is a need to carry out an effective and sustainable weed management process, integrating the various control methods (i.e., cultural, mechanical and chemical) in a harmonious way, without harming the entire agrarian ecosystem. Thus, intensive mechanization and herbicide use should be avoided. Herbicide resistance in some weed biotypes is a major concern today and must be tackled. On the other hand, the recent development of weed control technologies can promote higher levels of food production, lower the amount of inputs needed and reduce environmental damage, invariably bringing us closer to more sustainable agricultural systems. In this paper, we review the most common conventional and non-conventional weed control strategies from a sustainability perspective, highlighting the application of the precision and automated weed control technologies associated with precision weed management (PWM).info:eu-repo/semantics/publishedVersio

A chance-constrained approach for electric vehicle aggregator participation in the reserve market

As recorrentes preocupações ambientais têm levado a que se verifiquem alterações nos sistemas de energia, sendo que a aposta em sistemas distribuídos é já uma realidade, contudo a aposta em energia renovável está, normalmente, associada a intermitência no que diz respeito ao aproveitamento de energia proveniente do sol, vento, ondas, etc. Assim, neste paradigma, surgem os veículos elétricos que fazem parte do sistema e têm boas perspetivas de verem a sua penetração a aumentar exponencialmente num futuro próximo, pelo que devem ser estudadas novas formas de relação entre este recurso e os agentes de mercado. Neste momento, já é possível carregar e descarregar os veículos elétricos, o que, auxiliado pelas decisões e algoritmos corretos, pode contribuir com um apoio fundamental para a rede de energia tratar de forma simplificada congestionamentos e variações nos valores nominais de tensão e frequência. Tudo isto, está dependente da disponibilidade do proprietário do veículo para fornecer este tipo de serviço e que estados mínimos de carga sejam assegurados para as viagens diárias. Geralmente, os operadores da rede elétrica gerem elevados níveis de geração e carga, pelo que surge a necessidade do conceito de agregador de veículos elétricos, que terá a função de juntar vários veículos elétricos para assim corresponder de forma mais eficaz e com capacidade de oferta conforme as necessidades da rede.Neste trabalho, pretende-se otimizar o lucro do agregador, que poderá estar sujeito a penalidades em caso de falha no fornecimento de reserva a subir ou a descer, não colocando de parte a fiabilidade no fornecimento do serviço ao mercado de reserva. Deste modo, são utilizadas técnicas de otimização estocástica que pretendem modelar incertezas de uma pequena frota de veículos elétricos como disponibilidade para fornecer o serviço e perfis de consumo. A técnica de otimização chance-constrained, mais precisamente as relaxações Big-M e McCormick, são aplicadas a fim de analisar o risco da oferta que o agregador deve submeter em mercado.Para situações de mercado real, mais precisamente o FCR-N na Dinamarca, são explorados diversos cenários para diferentes níveis de risco submetidos em mercado, diferentes probabilidades de o veículo estar conectado à redeThe recurring environmental concerns have led to changes in energy systems, and the investment in distributed systems is in progress, however, the investment in renewable energy is usually associated with intermittent with regard to the use of energy from the sun, wind, waves, etc. Thus, within this scope, electric vehicles that are part of the system rises and stand good chances of seeing their penetration increase significantly in the near future, so new forms of relationship between this resource and the market agents should be addressed. At this point, it is already possible to charge and discharge electric vehicles, which, aided by correct decisions and algorithms, can contribute with a fundamental support for the energy network to deal in a simplified way with congestion and fluctuations in voltage and frequency. It all depends on the willingness of the vehicle owner to provide this type of service and that minimum states of charge are ensured for the daily trips. In general, electricity grid operators manage high power generation and load capacities, so there is a demand for the concept of electric vehicle aggregator, which will have the function to bring together several electric vehicles to correspond more effectively and with supply capacity according to the requirements of the grid.The aim of this work is to optimise the profit of the aggregator, which may be subject to penalties in the event of a failure in the provision of reserve upward or downward, regardless of the reliability in the provision of the service to the reserve market. Therefore, stochastic optimization techniques are used to model uncertainties of a small fleet of electric vehicles as availability to provide the service and consumption profiles. The optimization technique chance-constrained, namely Big-M and McCormick the relaxation methods, are applied in order to analyze the risk the aggregator must submit in the market. For real market cases, specifically the FCR-N in Denmark, several scenarios are analyzed for different levels of risk submitted in the market, different probabilities of the vehicle being connected to the grid

First record of the Mediterranean asteroid Sclerasterias richardi (Perrier in Milne-Edwards 1882) in the Azores Archipelago (NE Atlantic Ocean)

The first occurrence of the Mediterranean fissiparous asteroid Sclerasterias richardi (Perrier in Milne-Edwards 1882) is reported from the Azores based upon dredged material off the south coast of São Miguel Island at 135 m depth. This record represents a considerable expansion of the species’ geographic range, otherwise reported with certainty only from the Mediterranean Sea. S. richardi is capable of producing long-lived planktotrophic larvae with high dispersal potential to reach remote areas such as the Azores. Alternatively, this species is also capable of reproducing asexually through fission, which could insure the maintenance of viable numbers in a stranded population. The presence of S. richardi in Azorean waters and its rarity in an otherwise thoroughly investigated area does not necessarily imply a recent arrival nor a human-mediated introduction, as the depths in consideration (80-700 m) are also the least studied in the archipelago.info:eu-repo/semantics/publishedVersio

The inter-community competition as a factor for sustainability and differentiation of tourism product : the case of National Park of Peneda Gerês

The inter-community competition through its local traditions may emerge as a decisive factor to pave the way for the forthcoming of sustainable touristic opportunities, involving communities and contributing decisively to its economic development. The Assumption of the Identity Power (Castells, 1999) by the local communities emerges as a key factor to strengthen their identity. The isolation of certain communities, usually regarded as negative, strongly favours their involvement around their values, encouraging and promoting the emergence of rivalries and consequent inter-community competitions

Academic analytics: mapping the genome of the University

Higher education institutions have multiple technologic subsystems for administrative, pedagogical management, and quality purposes, which gather an immense volume of data from various sources and which do not communicate with each other. The domain of the analytic performances in education emerges from the need to aggregate multiple sources of data, which the complexity of treatment associated with the ease of mobilizing selected information will make it possible to understand reality and optimize management actions. In this paper, we present the architecture and results achieved in the development of an academic analytics aggregator of multiple sources of data on the educational activity.info:eu-repo/semantics/publishedVersio