2021
Autores
Chen, X; Ou, M; Liang, Y; Comite, U; Duarte, N; Yue, G;
Publicação
ACM International Conference Proceeding Series
Abstract
Based on the perspective of information asymmetry theory and transaction cost theory, this paper discusses the effect of agricultural industrialization organizations on the quality of agricultural products. Through the survey of litchi growers in Guangdong Province and surrounding areas, it designs indicators suitable for measuring litchi quality from the two dimensions of safety and texture, uses factor analysis, correlation analysis, OLS model to test the hypothesis proposed herein. The results show that: the involvement of agricultural industrialization organizations has played an important role in improving litchi quality of growers. Enlightenment: unified management and unified standards through industrial organization forms such as enterprises, cooperatives, and associations are an important way to implement large-scale production of litchi, strengthen respective advantages, share risks, seek mutual benefit and win-win results. Government departments should play a leading and propaganda role, provide financial and technical support, improve the service system for the industrialization of the litchi industry, cultivate leading litchi enterprises, and accelerate the development of professional litchi cooperatives, associations and other intermediary organizations to make them become standardized and competitive main market players. © 2021 ACM.
2021
Autores
Sousa, M; Carneiro, D;
Publicação
PROCEEDINGS OF 2021 16TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI'2021)
Abstract
Usually, Machine Learning systems are seen as something fully automatic. Recently, however, interactive systems in which human experts actively contribute towards the learning process have shown improved performance when compared to fully automated ones. This may be so in scenarios of Big Data, scenarios in which the input is a data stream, or when there is concept drift. In this paper, we present a system for supporting auditors in the task of financial fraud detection. The system is interactive in the sense that the auditors can provide feedback regarding the instances of the data they use, or even suggest new variables. This feedback is incorporated into newly trained Machine Learning models which improve over time.
2021
Autores
Carneiro, D; Oliveira, F; Novais, P;
Publicação
Ambient Intelligence - Software and Applications - 12th International Symposium on Ambient Intelligence, ISAmI 2021, Salamanca, Spain, 6-8 October, 2021.
Abstract
Machine Learning problems are significantly growing in complexity, either due to an increase in the volume of data, to new forms of data, or due to the change of data over time. This poses new challenges that are both technical and scientific. In this paper we propose a Distributed Learning System that runs on top of a Hadoop cluster, leveraging its native functionalities. It is guided by the principle of data locality. Data are distributed across the cluster, so models are also distributed and trained in parallel. Models are thus seen as Ensembles of base models, and predictions are made by combining the predictions of the base models. Moreover, models are replicated and distributed across the cluster, so that multiple nodes can answer requests. This results in a system that is both resilient and with high availability. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
2021
Autores
Monteiro, JP; Ramos, D; Carneiro, D; Duarte, F; Fernandes, JM; Novais, P;
Publicação
INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS
Abstract
In the last years, organizations and companies in general have found the true potential value of collecting and using data for supporting decision-making. As a consequence, data are being collected at an unprecedented rate. This poses several challenges, including, for example, regarding the storage and processing of these data. Machine Learning (ML) is also not an exception, in the sense that algorithms must now deal with novel challenges, such as learn from streaming data or deal with concept drift. ML engineers also have a harder task when it comes to selecting the most appropriate model, given the wealth of algorithms and possible configurations that exist nowadays. At the same time, training time is a stronger restriction as the computational complexity of the training model increases. In this paper we propose a framework for dealing with these challenges, based on meta-learning. Specifically, we tackle two well-defined problems: automatic algorithm selection and continuous algorithm updates that do not require the retraining of the whole algorithm to adapt to new data. Results show that the proposed framework can contribute to ameliorate the identified issues.
2021
Autores
Rocha, R; Carneiro, D; Novais, P;
Publicação
NEUROCOMPUTING
Abstract
Traditional explicit authentication mechanisms, in which the device remains unlocked after the introduction of some kind of password, are slowly being complemented with the so-called implicit or continuous authentication mechanisms. In the latter, the user is constantly monitored in one or more ways, in search for signs of unauthorized access, which may happen if a third party has access to the phone after it has been unlocked. There are some different forms of continuous authentication, some of which based on Machine Learning. These are generally black box models, that provide a decision but not an explanation. In this paper we propose an approach for continuous authentication based on behavioral biometrics, machine learning, and that includes domain-dependent aspects for the user to interpret the actions and decisions of the system. It is non-intrusive, does not require any additional hardware, and can be used continuously to monitor user identity.
2021
Autores
Carneiro, D; Veloso, P; Guimarães, M; Baptista, J; Sousa, M;
Publicação
Proceedings of 4th International Workshop on eXplainable and Responsible AI and Law co-located with 18th International Conference on Artificial Intelligence and Law (ICAIL 2021), Virtual Event, Sao Paolo, Brazil, June 21, 2021.
Abstract
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