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Publicações

2020

Simulating Tariff Impact in Electrical Energy Consumption Profiles With Conditional Variational Autoencoders

Autores
Bregere, M; Bessa, RJ;

Publicação
IEEE ACCESS

Abstract
The implementation of efficient demand response (DR) programs for household electricity consumption would benefit from data-driven methods capable of simulating the impact of different tariffs schemes. This paper proposes a novel method based on conditional variational autoencoders (CVAE) to generate, from an electricity tariff profile combined with weather and calendar variables, daily consumption profiles of consumers segmented in different clusters. First, a large set of consumers is gathered into clusters according to their consumption behavior and price-responsiveness. The clustering method is based on a causality model that measures the effect of a specific tariff on the consumption level. Then, daily electrical energy consumption profiles are generated for each cluster with CVAE. This non-parametric approach is compared to a semi-parametric data generator based on generalized additive models. Experiments in a publicly available data set show that, the proposed method presents comparable performance to the semi-parametric one when it comes to generating the average value of the original data (13% difference in root mean square error). The main contribution from this new method is the capacity to reproduce rebound and side effects in the generated consumption profiles. Indeed, the application of a special electricity tariff over a time window may also affect consumption outside this time window. Another contribution is that the proposed clustering approach is capturing the reaction to a tariff change. When compared to a clustering method with classical features (min, max and average consumption), the improvement in the Calinski-Harabasz index was 128% for consumers associated with tariff changes.

2020

Failure Detection of an Air Production Unit in Operational Context

Autores
Barros, M; Veloso, B; Pereira, PM; Ribeiro, RP; Gama, J;

Publicação
IoT Streams for Data-Driven Predictive Maintenance and IoT, Edge, and Mobile for Embedded Machine Learning - Second International Workshop, IoT Streams 2020, and First International Workshop, ITEM 2020, Co-located with ECML/PKDD 2020, Ghent, Belgium, September 14-18, 2020, Revised Selected Papers

Abstract
The transformation of industrial manufacturing with computers and automation with smart systems leads us to monitor and log of industrial equipment events. It is possible to apply analytic approaches, and to find interpretive results for strategic decision making, providing advantages such as failure detection and predictive maintenance. Over the last years, many researchers have been studying the application of machine learning techniques to improve such tasks. In this context, we develop a system capable of detect anomalies on an Air Production Unit (APU), taking into consideration the peak frequency of each sensor. The study started with the analysis of the sensors installed on the APU, defining its normal behavior and its failure mode. Using that information, we define rules, to monitor the APU, to detect anomalies on its components, and to predict possible failures. The definition of rules was based on the peak frequency analysis, which allowed the setting of boundaries of normality for the APU working modes and, thus, the identification of anomalies. © 2020, Springer Nature Switzerland AG.

2020

A Survey of Mobile Ticketing Services in Urban Mobility Systems

Autores
Ferreira, MC; Dias, TG; Falcão e Cunha, J;

Publicação
International Journal of Smart Sensor Technologies and Applications

Abstract
Modern mobile ticketing service solutions facilitate access to mobility services and free customers from difficult purchasing decisions. However, implementing these solutions is complex, as they involve many different stakeholders, with sometimes conflicting interests. This paper presents a survey of mobile ticketing services in the urban mobility context. It starts by defining mobile ticketing and explores the different electronic ticket schemes that are being implemented around the world, as well as the most used technologies to provide the service. Then, it addresses the complex mobile ticketing ecosystem, identifying the main actors involved, their motivations, and concerns. This allows the authors to define their role and contribution to the mobile ticketing ecosystem. Finally, the paper presents future trends and research directions related to mobile ticketing services, being a valuable guide for researchers and practitioners.

2020

Classification of Optical Coherence Tomography using Convolutional Neural Networks

Autores
Saraiva, AA; Santos, DBS; Pedro, P; Moura Sousa, JVM; Fonseca Ferreira, NMF; Batista Neto, JESB; Soares, S; Valente, A;

Publicação
PROCEEDINGS OF THE 13TH INTERNATIONAL JOINT CONFERENCE ON BIOMEDICAL ENGINEERING SYSTEMS AND TECHNOLOGIES, VOL 3: BIOINFORMATICS

Abstract
This article describes a classification model of optical coherence tomography images using convolution neural network. The dataset used was the Labeled Optical Coherence Tomography provided by (Kermany et al., 2018) with a total of 84495 images, with 4 classes: normal, drusen, diabetic macular edema and choroidal neovascularization. To evaluate the generalization capacity of the models k-fold cross-validation was used. The classification models were shown to be efficient, and as a result an average accuracy of 94.35% was obtained.

2020

PseudoChecker: an integrated online platform for gene inactivation inference

Autores
Alves, LQ; Ruivo, R; Fonseca, MM; Lopes Marques, M; Ribeiro, P; Castro, LFC;

Publicação
NUCLEIC ACIDS RESEARCH

Abstract
The rapid expansion of high-quality genome assemblies, exemplified by ongoing initiatives such as the Genome-10K and i5k, demands novel automated methods to approach comparative genomics. Of these, the study of inactivating mutations in the coding region of genes, or pseudogenization, as a source of evolutionary novelty is mostly overlooked. Thus, to address such evolutionary/genomic events, a systematic, accurate and computationally automated approach is required. Here, we present PseudoChecker, the first integrated online platform for gene inactivation inference. Unlike the few existing methods, our comparative genomics-based approach displays full automation, a built-in graphical user interface and a novel index, PseudoIndex, for an empirical evaluation of the gene coding status. As a multi-platform online service, PseudoChecker simplifies access and usability, allowing a fast identification of disruptive mutations. An analysis of 30 genes previously reported to be eroded in mammals, and 30 viable genes from the same lineages, demonstrated that PseudoChecker was able to correctly infer 97% of loss events and 95% of functional genes, confirming its reliability. PseudoChecker is freely available, without login required, at http://pseudochecker.ciimar.up.pt.

2020

Helping software developers through live software metrics visualization

Autores
Fernandes, S; Restivo, A; Ferreira, HS; Aguiar, A;

Publicação
Programming'20: 4th International Conference on the Art, Science, and Engineering of Programming, Porto, Portugal, March 23-26, 2020

Abstract
With the increasing complexity of software systems, software developers would benefit from instant and continuous feedback about the system they are maintaining and evolving. Despite existing several solutions providing feedback and suggesting improvements, many tools require explicit invocations, leading developers to miss some improvement opportunities, such as important refactorings, due to the loss of their train of thought. Therefore, to address these limitations, we developed a Visual Studio Code plugin providing real-time feedback - - and also information about each commit made to the version control system. This tool is also capable of recommending two types of refactorings. To validate this approach, we did a preliminary controlled experiment using hypothesis-tests to check specific results. However, in this initial stage, we didn't have enough data to confirm our research questions, and we weren't able yet to confirm the main hypothesis. © 2020 Owner/Author.

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