Loading...
Person
Ferreira Mosquera Fernandez, Carlos Fernando
5 results
Search Results
Now showing 1 - 5 of 5
- Aplicação de Técnicas de Machine Learning no Âmbito do Diagnóstico da Ocorrência de Curtos-Circuitos Estatóricos em Motores de Indução TrifásicosPublication . Fernandez, Carlos Fernando Ferreira Mosquera; Cardoso, António João MarquesA Indústria 4.0 traz associado o conceito de fábricas inteligentes, que surgem para atender a uma necessidade crescente de elevada flexibilidade e eficiência na fabricação dos produtos. Os motores de indução trifásicos já são utilizados em larga escala pela indústria e terão um papel primordial nas Smart Factories. A fim de mantê-los em funcionamento, com elevado grau de fiabilidade, e de reduzir os custos associados a paragens e intervenções, torna-se necessária a identificação de avarias, ainda em estágio precoce, de forma a programar a manutenção antes da paragem total daqueles equipamentos. Os métodos de diagnóstico de avarias online vêm sendo alvo de estudo há muitos anos. A avaliação dos resultados da aplicação desses métodos de diagnóstico depende de um especialista para uma interpretação e um diagnóstico precisos. Este trabalho aborda o uso de Inteligência Artificial para a deteção de avarias em motores elétricos, de forma automatizada, ainda em estágio precoce. Foram utilizados algoritmos de Machine Learning, nomeadamente Support Vector Machines e Decision Trees para a deteção de curtos-circuitos entre espiras, de forma preditiva, baseando-se em dados reais adquiridos no Laboratório de Sistemas Electromecatrónicos do CISE - Centro de Investigação em Sistemas Electromecatrónicos. Como principal diferença em relação a outros trabalhos, será apresentada uma abordagem baseada no Extended Park’s Vector Approach, que já é atualmente utilizada para esta finalidade. Trata-se, portanto, de uma abordagem híbrida e tem como principal objetivo obter o máximo de eficiência com o mínimo de features, a partir de uma ferramenta já utilizada para este fim. Como resultado, é apresentado um sistema de diagnóstico automatizado para a deteção de curtos-circuitos estatóricos em motores de indução trifásicos que utiliza Support Vector Machine e Decision Tree, contemplando cenários de funcionamento distintos, nomeadamente condição normal e condição de desequilíbrio na rede de alimentação, relativo ao deslocamento de fase ou à amplitude das tensões. Após a otimização dos modelos, será realizada a validação em dados novos e os seus resultados serão discutidos.
- Fostering Awareness on Environmentally Sustainable Technological Solutions for the Post-Harvest Food Supply ChainPublication . Fernandez, Carlos M.; Alves, Joel; Gaspar, Pedro Dinis; Lima, Tânia M.This study presents a current status and future trends of innovative and environmentally sustainable technological solutions for the post-harvest food supply chain and the food industry, in terms of ecological packaging, active, and/or intelligent packaging. All these concerns are currently highlighted due to the strong increase in the purchase/sale of products on online platforms, as well as the requirements for stricter food security and safety. Thus, this study aims to increase the global awareness of agro-industrial micro, small, and medium size enterprises for the adoption of innovative food solutions though industry digitalization (Industry 4.0), associated logistics and circular economy, with a concern for cybersecurity and products information, communication and shelf-life extension. The adoption of these guidelines will certainly foster along the complete food chain (from producer to consumer, with all intermediary parties) the awareness on environmentally sustainable technological solutions for the post-harvest food supply chain, and thus, promoting the future food sustainability required by the population increase, the climate change, the exodus of rural population to urban areas, and food loss and waste.
- Innovative processes in smart packaging. A systematic reviewPublication . Fernandez, Carlos M.; Alves, Joel; Gaspar, Pedro Dinis; Lima, Tânia M.; Silva, Pedro Dinho daSmart packaging provides one possible solution that could reduce greenhouse gas emissions. In comparison with traditional packaging, which aims to extend the product's useful life and to facilitate transport and marketing, smart packaging allows increased efficiency, for example by ensuring authenticity and traceability from the product's origin, preventing fraud and theft, and improving security. Consequently, it may help to reduce pollution, food losses, and waste associated with the food supply chain. However, some questions must be answered to fully understand the advantages and limitations of its use. What are the most suitable smart packaging technologies for use in agro-industrial subsectors such as meat, dairy, fruits, and vegetables, bakery, and pastry? What are the opportunities from a perspective of life extension, process optimization, traceability, product quality, and safety? What are the future challenges? An up-to-date, systematic review was conducted of literature relevant to the application of indicator technologies, sensors, and data carriers in smart packaging, to answer these questions.
- Decision Support System to Assign Price Rebates of Fresh Horticultural Products Based on Quality DecayPublication . Matos, Cláudia; Maciel, Vinicius Biasutti Pitol; Fernandez, Carlos M.; Lima, Tânia M.; Gaspar, Pedro DinisHorticultural products ripeness brings out features like flavor, texture, aroma, skin changes and finally, generates waste due to its spoilage. To avoid or minimize it, many traders as supermarkets, mini-markets and groceriesmake changes in their fruit’s prices just before expiration date. However, customers’ acceptability changes during the products shelf life, which leads to selling decrease along products quality decay and, consequently, profit decrease. This behavior establishes a challenging scenario to manage stock replenishment and pricing strategies. Many studies present inventory management model for perishable food products but considering only physical quantity deterioration whereas some few authors discuss dynamic pricing, considering quantity and quality deterioration simultaneously. Aiming the optimization of profit in traders, this work introduces a decision support system to assign price rebates of fresh horticultural products based on quality decay. To achieve this goal, two methodologies were followed. The first one consists in using experimental test results formodeling purposes, based on Pontryagin’smaximum principle, using apple, banana and strawberry. The former consists in using questionnaire as sensitivity analysis of quality from customers’ perspective, bringing more reliability and criteria for modeling, since quality could be subjective. The result is a computational decision support system to predict the optimum price for a specific fruit during shelf life. The main objective is to extend the applicability of the computational tool in order to overcome challenges related to limitations of logistics, allowing mini-markets and groceries use this software.
- Development of Technological Capabilities through the Internet of Things (IoT): Survey of Opportunities and Barriers for IoT Implementation in Portugal’s Agro-IndustryPublication . Gaspar, Pedro Dinis; Fernandez, Carlos M.; Soares, Vasco N. G. J.; Caldeira, João; Silva, HélioThe agro-industrial sector consumes a significant amount of natural resources for farming and meat production. By 2050, population growth is expected, generating more demand and, consequently, more consumption of scarce resources. This challenging scenario is a concern of the European Commission, revealed in the Green Deal commitment and by the United Nations’ 12th goal of sustainable development. Thus, organizations must increase productivity and be more sustainable as soon as possible. Internet of Things (IoT) is introduced as a solution to facilitate agro-food companies to be more eco-efficient, mainly facing difficulties on farms, such as food loss and waste, best efficiency in management of resources, and production. The deployment of this technology depends on the stage of maturity and potential of implementation. To assess and characterize companies, with respect of IoT implementation, a survey was applied in 21 micro, small and medium agro-food companies, belonging to milk, honey, olive oil, jams, fruticulture, bakery and pastry, meat, coffee, and wine sectors, in the central region of Portugal. As results, this paper reveals the stage of maturity, level of sophistication, potential, opportunities, solutions, and barriers for implementation of IoT. Additionally, suggestions and recommendations to improve practices are discussed.