2023
Authors
Silva, A; Teixeira, R; Fontes Carvalho, R; Coimbra, M; Renna, F;
Publication
2023 45TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY, EMBC
Abstract
In this paper we study the heart sound segmentation problem using Deep Neural Networks. The impact of available electrocardiogram (ECG) signals in addition to phonocardiogram (PCG) signals is evaluated. To incorporate ECG, two different models considered, which are built upon a 1D U-net - an early fusion one that fuses ECG in an early processing stage, and a late fusion one that averages the probabilities obtained by two networks applied independently on PCG and ECG data. Results show that, in contrast with traditional uses of ECG for PCG gating, early fusion of PCG and ECG information can provide more robust heart sound segmentation. As a proof of concept, we use the publicly available PhysioNet dataset. Validation results provide, on average, a sensitivity of 97.2%, 94.5%, and 95.6% and a Positive Predictive Value of 97.5%, 96.2%, and 96.1% for Early-fusion, Late-fusion, and unimodal (PCG only) models, respectively, showing the advantages of combining both signals at early stages to segment heart sounds.
2023
Authors
Elhawash, AM; Araujo, RE; Lopes, JAP;
Publication
2023 IEEE VEHICLE POWER AND PROPULSION CONFERENCE, VPPC
Abstract
This paper aims at researching the design of a current controller for an interleaved Buck converter used to feed a high current 5 kW Polymer electrolyte membrane (PEM) electrolyzer representing a module stack level. The main challenge is to design a robust controller that ensures operation over a wide range of electrolyzer operating points while guaranteeing control requirements and current sharing between the converters. The developed control scheme ensures responsiveness to the requirements of the grid's ancillary services and control over the dynamics of the electrolyzer. MATLAB/Simulink simulation results with dSPACE compatible models are presented to validate the lead-lag controller, designed using root locus, achieving a ripple current of 0.1 A, a 0.3% steady-state error, and a settling time of 50 ms for a step response.
2023
Authors
Carneiro, D; Carvalho, M;
Publication
INTELLIGENT SYSTEMS AND APPLICATIONS, VOL 2
Abstract
The expectations of Machine Learning systems are becoming increasingly demanding, namely in what concerns the diversity of applications, the expected accuracy, and the pressure for results. However, there are cases in which Human experts are needed to label the data, which may have a significant cost in terms of human resources and time. In these cases, it is often best to learn on-the-fly, without expecting for the whole data to be labeled. Often, it is desirable to guide the Human annotators into focusing on the more relevant instances: this constitutes the so-called active learning. In this paper we propose an approach in which a clustering algorithm is used to find groups of similar instances. Then, the procedure is guided with the objective of favoring the annotation of the groups that are under-represented in the labeled dataset. Results show that this approach leads to models that are, over time, more accurate and reliable.
2023
Authors
Paiva, JC; Queirós, R; Gasiba, T;
Publication
ICPEC
Abstract
Malicious actors can cause severe damage by exploiting software vulnerabilities. In industrial settings, where critical infrastructures rely on software, handling these vulnerabilities with utmost care is crucial to prevent catastrophic consequences. For this purpose, a cybersecurity awareness platform called Sifu was created. This platform automatically assesses challenges to verify its compliance to secure coding guidelines. Using an artificial intelligence method, an interactive component provides players with solution-guiding hints. This paper presents an improved version of the Sifu platform, which evolves the tool in the following aspects: architecture, data model and user interface. The new platform separates the server and client-side using a REST API architecture. It also accommodates an intrinsic and richer layer of gamification, which explores the concept of game rooms at an organizational and gamification level. Finally, it offers an improved interactive training experience for individuals and organizations through a responsive and intuitive single-page web application.
2023
Authors
Caldeira, C; Pereira, D; Santos, JD; Guimarães, C; Almeida, F;
Publication
Springer Proceedings in Earth and Environmental Sciences
Abstract
Innovation is a key driver to address the challenges of sustainability. To achieve this goal, the various entities participating in the innovation process must work together to ensure that research methodologies and results are aligned with the needs and expectations of society. Having a conceptual and practical approach that allows exploring and measuring how projects are fulfilling this expectation is key in this process. In this sense, this study aims to explore the relevance of this phenomenon for the development of innovation practices and to characterize and compare several responsible innovation assessment tools (RIATs) that can be used by research teams. A qualitative methodology is used to identify, map, and compare the characteristics of each RIAT. The main strengths and limitations of each approach are also explored. The findings reveal a total of 18 RIATs and 16 dimensions. The challenge is to get a harmonious balance between these various dimensions and to have this analysis performed in the early stages of each project. This study makes practical contributions by identifying areas that each project must assess and ensure for its innovation activities to be socially desirable and ethically acceptable. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.
2023
Authors
Escobar, JJL; Ricardo, M; Campos, R; Gil Castiñeira, F; Redondo, RPD;
Publication
INTERNET OF THINGS
Abstract
Management of network resources in advanced IoT applications is a challenging topic due to their distributed nature from the Edge to the Cloud, and the heavy demand of real-time data from many sources to take action in the deployment. FANETs (Flying Ad-hoc Networks) are a clear example of heterogeneous multi-modal use cases, which require strict quality in the network communications, as well as the coordination of the computing capabilities, in order to operate correctly the final service. In this paper, we present a Virtual Network Embedding (VNE) framework designed for the allocation of dataflow applications, composed of nano-services that produce or consume data, in a wireless infrastructure, such as an airborne network. To address the problem, an anypath-based heuristic algorithm that considers the quality demand of the communication between nano-services is proposed, coined as Quality-Revenue Paired Anypath Dataflow VNE (QRPAD-VNE). We also provide a simulation environment for the evaluation of its performance according to the virtual network (VN) request load in the system. Finally, we show the suitability of a multi-parameter framework in conjunction with anypath routing in order to have better performance results that guarantee minimum quality in the wireless communications.
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