ESTGV - DI - Artigo em revista científica, não indexada ao WoS/Scopus
Permanent URI for this collection
Browse
Recent Submissions
- 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.
- 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.
- 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.
- Openstack: a virtualization overviewPublication . Martins, Pedro Oliveira; Mechraoui, Faouzi; Caldeira, FilipeThe major cloud computing software companies offer a new concept, on which resources are virtualized to provide these as a service on the internet. Currently, there are multiple service providers, and additional options to virtualize services on-premises. OpenStack is an open-source alternative to create virtual local or cloud setups, which supports petabytes of data, unlimited scale, and configurable networking. These features make this tool suitable for large scale virtualization, reducing maintenance costs and optimizing hardware resource utilization (e.g., schools, government). This paper presents an overview of the study of the OpenStack software, oriented to build a scalable hosting architecture suitable for an educational setup. Functional and architectural details are discussed to implement unique cloud computing to fit virtualization purposes. An experimental virtualization setup is described in the scope of an educational scenario. Finally, a guideline to configure OpenStack is given.
- On the Use of Ontology Data for Protecting Critical InfrastructuresPublication . Henriques, João; Caldeira, Filipe; Cruz, Tiago; Simões, PauloModern societies increasingly depend on products and services provided by Critical Infrastructures (CI). The Security Information and Event Management (SIEM) systems in charge of protecting these CIs usually collect and process data from specialised sources. However, they usually integrate only a small fraction of the whole data sources existing in the CI. Valuable generic data sources are missing in this process, such as human resources databases, staff check clocks, and outsourced service providers. To address this gap, the authors propose a framework that takes a Semantic Web approach for automated collection and processing of corporate data from multiple heterogeneous sources.
- Policy-based networking: Applications to firewall managementPublication . Caldeira, Filipe; Monteiro, E.This paper describes a policy-based approach to firewall management. The Policy-Based Networking (PBN) architecture proposed by the Policy Framework Group of lnternet Engineering Task Force (1ETF) is analysed, together with the communication protocols, policy specification languages, and the necessary information models. An overview of policy specification languages applicability to PBN architecture is presented paying particular attention to the specification of security policies through Security Policy Specification Language (SPSL). The Common Open Policy Service protocol (coPs) and its variant, coPs for Policy provisioning (COPS-PR), both used for the transport of policy information, are also presented. The paper continues with a description of an application of the PBN architecture to firewall management. The proposed architecture is presented and its implementation issues are analysed with some usage examples. The paper concludes with the evaluation of the policybased approach to firewall management.
- Trust Based Interdependency Weighting for On-Line Risk Monitoring in Interdependent Critical InfrastructuresPublication . Caldeira, Filipe; Schaberreiter, Thomas; Varrette, Sébastien; Monteiro, Edmundo; Simões, Paulo; Bouvry, Pascal; Khadraoui, DjamelCritical infrastructure (CI) services are constantly consumed by the society and are not expected to fail. A common definition states that CIs are so vital to our society that a disruption would have a severe impact on both the society and the economy. CI sectors include, amongst others, electricity, telecommunication and transport. CIs can be mutually dependent on each others services and a failure in one of these elements can cascade to another (inter)dependent CI. CI security modelling was introduced in previous work to enable on-line risk monitoring in CIs that depend on each other by exchanging risk alerts expressed in terms of a breach of Confidentiality, a breach of Integrity and degrading Availability (C,I,A). While generally providing a solid basis for risk monitoring, there is no way of evaluating if a risk alert received from an external CI is accurate. In this paper we propose a solution to this problem by adding a trust based component to the CI security model in order to improve its accuracy and resilience to inconsistent or inaccurate risk alerts provided by (inter)dependent CIs, allowing to evaluate the correctness of the received alerts. The proposed approach is validated on a realistic scenario by evaluating a dependency between the computing and the telecommunication sectors in the context of the Grid'5000 platform.
- 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.
- 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.
- 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.