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Publications

2017

A Data-Driven Feature Extraction Method for Enhanced Phonocardiogram Segmentation

Authors
Renna, F; Oliveira, J; Coimbra, MT;

Publication
2017 COMPUTING IN CARDIOLOGY (CINC)

Abstract
In this work, we present a method to extract features from heart sound signals in order to enhance segmentation performance. The approach is data-driven, since the way features are extracted from the recorded signals is adapted to the data itself. The proposed method is based on the extraction of delay vectors, which are modeled with Gaussian mixture model priors, and an information-theoretic dimensionality reduction step which aims to maximize discrimination between delay vectors in different segments of the heart sound signal. We test our approach with heart sounds from the publicly available PhysioNet dataset showing an average F-1 score of 92.6% in detecting S-1 and S-2 sounds.

2017

Context analysis in energy resource management residential buildings

Authors
Madureira, B; Pinto, T; Fernandes, F; Vale, Z;

Publication
2017 IEEE Manchester PowerTech, Powertech 2017

Abstract
This paper presents a context analysis methodology to improve the management of residential energy resources by making the decision making process adaptive to different contexts. A context analysis model is proposed and described, using a clustering process to group similar situations. Several clustering quality assessment indices, which support the decisions on how many clusters should be created in each run, are also considered, namely: the Calinski Harabasz, Davies Bouldin, Gap Value and Silhouette. Results show that the application of the proposed model allows to identify different contexts by finding patterns of devices' use and also to compare different optimal k criteria. The data used in this case study represents the energy consumption of a generic home during one year (2014) and features the measurements of several devices' consumption as well as of several contextual variables. The proposed method enhances the energy resource management through adaptation to different contexts. © 2017 IEEE.

2017

Virtual Enterprise integration management based on a Meta-enterprise - a PMBoK approach

Authors
Ferreira, L; Lopes, N; Avila, PS; Castro, H; Varela, MLR; Putnik, GD; Martinho, R; Rijo, R; Miranda, IM; Cruz Cunha, MM;

Publication
CENTERIS 2017 - INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS / PROJMAN 2017 - INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT / HCIST 2017 - INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES, CENTERI

Abstract
A Virtual Enterprise (VE) can be viewed as a project, with a lifecycle corresponding to the period between its creation and integration of the constituting elements until its dissolution, comprehending its operation and including its reconfigurations. The authors propose that the VE lifecycle is aligned and can be managed using the frameworks provided by several bodies of knowledge, such as the PMBoK Guide. In this paper the authors propose an alignment referential between the Project Management phases defined by PMBoK and management processes during the VE lifecycle. (C) 2017 The Authors. Published by Elsevier B.V.

2017

Simulation of gas networks and leak detection using quadripole models

Authors
T. Baltazar, S; Lopes dos Santos, P; Azevedo Perdicoúlis, TP;

Publication
Applied Condition Monitoring

Abstract
A cost-effective, accurate, and robust leak detection method is essential in gas network management in order to reduce inspection time and to increase reliability in the system. This work presents a model-based leakage detection method; the gas dynamics are described by a linearized system of partial differential equations that is further reduced to a one-dimensional spatial model. By using an electrical analogy, a pipeline can be represented by a two-port network, where mass flow behaves like current and pressure like voltage. Four transfer function quadripole models are then established to describe the gas pipeline dynamics, depending on the variables of interest at the pipeline boundaries. A leak detection method is devised by employing mass flow data at boundaries and pressure data at some point of the pipeline, as well as by assessing the effects of the leakage on the pressure and mass flow along the pipeline. A case study has been built from operational data supplied by REN Gasodutos (the Portuguese gas company) to show the advantages of the proposed models. © Springer International Publishing AG 2017.

2017

Learning Entrepreneurship with Serious Games - A Classroom Approach

Authors
Almeida, FL;

Publication
CoRR

Abstract

2017

Evaluation of the Simulated Annealing and the Discrete Artificial Bee Colony in the Weight Tardiness Problem with Taguchi Experiments Parameterization

Authors
Santos, AS; Madureira, AM; Varela, MR;

Publication
INTELLIGENT SYSTEMS DESIGN AND APPLICATIONS (ISDA 2016)

Abstract
Meta-Heuristics (MH) are the most used optimization techniques to approach Complex Combinatorial Problems (COPs). Their ability to move beyond the local optimums make them an especially attractive choice to solve complex computational problems, such as most scheduling problems. However, the knowledge of what Meta-Heuristics perform better in certain problems is based on experiments. Classic MH, as the Simulated Annealing (SA) has been deeply studied, but newer MH, as the Discrete Artificial Bee Colony (DABC) still need to be examined in more detail. In this paper DABC has been compared with SA in 30 academic benchmark instances of the weighted tardiness problem (1 parallel to Sigma w(j)T(j)). Both MH parameters were fine-tuned with Taguchi Experiments. In the computational study DABC performed better and the subsequent statistical study demonstrated that DABC is more prone to find near-optimum solutions. On the other hand SA appeared to be more efficient.

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