ESTGV - DI - Artigo em revista científica, não indexada ao WoS/Scopus
URI permanente para esta coleção:
Navegar
Percorrer ESTGV - DI - Artigo em revista científica, não indexada ao WoS/Scopus por título
A mostrar 1 - 10 de 17
Resultados por página
Opções de ordenação
- Analysing the different interrelationships of soil organic carbon using machine learning approaches: Assessing the specific case of PortugalPublication . Pereira Domingues Martinho, Vítor João; Ramos, Tiago Brito; Castanheira, Nádia; Cunha, Carlos; Ferreira, António José Dinis; Pereira, José Luís da Silva; Sánchez-Carreira, Maria del CarmenGiven the importance of soil organic carbon (SOC) for sustainability, policymakers and researchers are particularly concerned with identifying the conditions that promote carbon storage in the soil. These assessments provide relevant support for the design of policy instruments aimed at increasing soil quality and its carbon sequestration capacity. The new technologies associated with the digital transition can bring relevant added value, namely through artificial intelligence methodologies, where machine learning approaches are important. In this context, this research aims to analyse the several interrelationships of SOC in the specific Portuguese context, with a focus on highlighting its main predictors and providing proposals for stakeholders (including policymakers). To achieve these objectives, statistics from the INFOSOLO database were considered and evaluated using machine learning algorithms to select the most important SOC predictors and identify accurate models. These interrelationships were quantified with cross sectional regressions and optimisation models. The results obtained provide relevant information for the design of adjusted policy measures that promote sustainable practices and increase soil quality. Generally, Portuguese soils have low organic carbon content due to soil features, climate circumstances and land management. Adjusted management of agroforestry activities is possibly the easiest part to deal with in this context.
- Beacons positioning detection, a novel approachPublication . Morgado, Francisco; Martins, Pedro; Caldeira, FilipeRecent Bluetooth Low Energy (BLE) beacons provide new opportunities to explore positioning. Beacon positioning determination using current approaches is supported by pre-calculated formulas, for generic beacons, whereas the position can be accurately estimated with a low error up to a small distance; or based on fingerprinting the signal for the given space. In both cases, the accuracy variate depending on hardware specifications and other conditions such as beacon brand, wrap material, temperature, wind, location, surrounding interference, battery strength, among others. This paper introduces a method for beacon-based positioning, based on signal strength measurements at key distances for each beacon. This method allows for different beacon types, brands, and conditions. Depending on each situation (i.e., hardware and location) it is possible to adapt the distance measuring curve to minimize errors and support higher distances, while at the same time keeping good precision. Moreover, this paper also presents a comparison with traditional positioning method, using formulas for distance estimation, and then position triangulation. Performed tests took place at the library of the campus of the Polytechnic Institute of Viseu. Experimental results show that the proposed position technique has 13.2% better precision than triangulation, for distances up to 10 meters.
- Design and implementation of a mediation system enabling secure communication among Critical InfrastructuresPublication . Castrucci, Marco; Neri, Alessandro; Caldeira, Filipe; Aubert, Jocelyn; Khadraoui, Djamel; Aubigny, Matthieu; Harpes, Carlo; Simoes, Paulo; Suraci, Vincenzo; Capodieci, PaoloNowadays, the increase of interdependencies among different Critical Infrastructures (CI) makes it more and more difficult to protect without using a systemic approach that considers a single infrastructure as part of a complex system of infrastructures. A strong collaboration among CI owners is required to avoid, or at least to limit the propagation of failures from one infrastructure to another and to put CI in safety mode. The key element enabling this required cooperation is the possibility for them to exchange relevant information related to the status of their infrastructures and to the services provided. In this paper, we present a middleware solution that allows CIs sharing real-time information, enabling the design and implementation of fault mitigation strategies and mechanisms to prevent the cascading phenomena generated by the failure propagation from one infrastructure to another.
- Design of Data Management Service Platform for Intelligent Electric Vehicle Charging Controller Multi-charger ModelPublication . Baptista, Pedro; Rosado, José; Caldeira, Filipe; Cardoso, FilipeThe electric charging solutions for the residential market imply, in many situations, an increase in the contracted power in order to allow to perform an efficient charging cycle that starts when the charger is connected and ends when the VE battery is fully charged. However, the increase in contracted power is not always the best solution for faster and more efficient charging. With a focus on the residential market, the presented architecture is suitable for single-use and shared connection points, which are becoming common in apartment buildings without a closed garage, allowing for sharing the available electrical connections to the grid. The multi-charger architecture allows using one or several common charging points by applying a mesh network of intelligent chargers orchestrated by a residential gateway. Managing the generated data load involves enabling data flow between several independent data producers and consumers. The data stream ingestion system must be scalable, resilient, and extendable.
- Flywheel -" A Bateria Electromecânica"..Publication . Carvalho, António Manuel Santos; Marques, Bruno Filipe; Apura, Paulo Fernando da CostaDesde sempre, o homem necessitou de fontes energéticas. Uma vez que essas fontes não estão sempre disponíveis, existe a necessidade de armazenar a energia para utilização posterior. Isso passa-se com os seres vivos que, alimentando-se, conservam a energia dos alimentos sob a forma de compostos químicos no próprio organismo. Com o desenvolvimento da civilização tornou-se óbvio o armazenamento de várias formas de energia. No caso de um painel solar, só se produz energia durante as horas do dia. Mas o homem também vive de noite, necessitando também de energia eléctrica. Torna-se então clara a necessidade de armazenar a energia produzida durante o dia, muitas vezes em excesso, pois nem sequer é utilizada.
- A Ghost Cell-Based Data Structure for Multiresolution MeshesPublication . Rodrigues, Rui; Morgado, José Francisco; Silva, Frutuoso; Gomes, AbelMultiresolution meshes enable us to build representations of geometric objects at different Levels of Detail (LODs). We introduce a multiresolution scheme whose data structure allows us to separately re- store the geometry and topology of a mesh during the refinement process. Additionally, we use a topological criterion (not a geometric criterion, as usual in the literature) to quickly simplify a mesh, what seems to make the corresponding simplification algorithm adequate for real-time appli- cations such as, for example, on-line computer games.
- Intelligent beacon location and fingerprintingPublication . Martins, Pedro; Abbasi, Maryam; Sa, Filipe; Celiclio, Jose; Morgado, Francisco; Caldeira, FilipeThe complex way radio waves propagate indoors, leads to the derivation of location using fingerprinting techniques. In this cases, location is computed relying on WiFi signals strength mapping. Recent Bluetooth Low Energy (BLE) provides new opportunities to explore positioning. Indoor location identification plays a fundamental role as a business and personal level. At a business level, indoor location pinpointing where GPS signal is nonexistent is used to advise users and send push notifications (e.g., stores publicity, guide persons with special needs, or even for emergency evacuation). In this work is studied how BLE beacons radio signals can be used for indoor location scenarios, as well as their precision. The proposed study is performed inside the campus of Viseu Polytechnic Institute, using hundreds of students, each with his smart-phone, as proof of concept. Experimental results show that BLE allows having less than 1.5 meters error approximately 90% of the times.
- Life cycle assessment of computers and electronic devices: A comprehensive review of environmental impactsPublication . Domingos Ferreira, Miguel; Domingos, idalina; Ferreira, José; IJASEATThe objective of this study was to evaluate Life Cycle Assessment studies applied to computers with respect to temporal and geographical distribution, research subjects, impact assessment methods, databases and software utilized, and principal findings. To achieve this, a bibliographical search was conducted using the Web of Science Core Collection database platform, using the keywords "Life cycle assessment" "AND" "computer" for title topic. The search yielded 12 publications selected from 28, for which a descriptive analysis was performed. It was determined that most of the studies (six in total) took place between 2011 and 2020. Geographically, the majority of these studies were conducted in Asia and the USA/Canada, with six studies in each region. The majority of studies (6) have aimed to evaluate the environmental impacts of computers (desktop/all-in-one). Regarding the impact assessment methods employed, there is considerable variation among ReciPe (2), Ecoindicator (2), IPCC (2), and CML (1), although some studies have utilized multiple methods. The primary findings indicate significant environmental benefits from adopting newer, energy-efficient technologies (APCs and LCDs), improving formal e-waste management, and focusing on recycling and sustainable manufacturing. Proper End-of-Life handling and the minimization of informal disposal also yield substantial environmental gains.
- LIFE CYCLE ASSESSMENT OF PIG PRODUCTION: A CASE STUDYPublication . Ferreira, José; Leite dos Santos, Lenise Maria; Domingos Ferreira, Miguel; OLIVEIRA VERONICA; RODRIGUES CARLA; FERREIRA ANTONIO; Domingos, idalina; IRAJPig farming plays a crucial socioeconomic role in the European Union (EU), with Germany, France, and Spain leading pork production. In Portugal, pig farming is vital for regional development and national economy. To ensure future sustainability, it is essential to identify the pig production activities that have the most significant environmental impacts. This study carried out a Life Cycle Assessment (cradle-to-gate) of pig production using a conventional system in central Portugal to identify the phases with the greatest environmental impact. LCA followed the ISO 14040/14044 standards, covering the production cycle, using 1 kg of live pig weight as a functional unit. The analyzed scenario encompasses everything from the production and growth of piglets to the pig fattening phase, including the formulation of specific feed for each stage of development, transport of inputs, use of diesel to generate electricity in the facilities, and management of pig manure. The results highlight feed production and piglet management as the most important steps. The study highlights the importance of sustainable practices in order to mitigate environmental issues such as human carcinogenic toxicity and the ecotoxicity of freshwater and marine water, emphasizing the need for improved strategies in pig farming.
- Os Novos Alunos da EST do Politécnico de Viseu.Publication . Francisco, Francisco F.; Martins, José Carlos M.; Bebiano, Rui A. Quadroso âmbito dum grupo de trabalho nomeado pela Comissão Coordenadora do Conselho Científico de 14 de Junho de 1996, realizaram-se alguns inquéritos, dos quais se destaca o que foi apresentado aos "Novos Alunos". A oportunidade de tornar público parte do estudo e algumas das conclusões retiradas do inquérito surgiu agora com a publicação da Millenium. Em síntese podemos dizer que a população estudantil da Escola Superior de Tecnologia é constituída por alunos jovens (média inferior a 20 anos), maioritariamente do sexo masculino (58%) e provenientes em grande parte da região de Viseu e concelhos limítrofes. Do litoral norte e centro vêm também muitos alunos (32%). A grande maioria inscreve-se no curso que pretende e na escola que deseja, com excepções registadas nos cursos de Eng. de Madeiras e Eng. do Ambiente. O curso maior é o de Gestão de Empresas e o mais pequeno o de Engenharia de Sistemas e Informática. O inquérito foi realizado no acto da matrícula e colocado anonimamente aos "Novos Alunos". Responderam quatrocentos e dezoito alunos, estimando-se que com os alunos retidos no primeiro ano a população escolar seja superior a meio milhar de indivíduos.