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Publications

2018

MAESTRI Efficiency Framework: The concept supporting the Total Efficiency Index. Application case study in the metalworking sector

Authors
Baptista, AJ; Lourenco, EJ; Silva, EJ; Estrela, MA; Pecas, P;

Publication
25TH CIRP LIFE CYCLE ENGINEERING (LCE) CONFERENCE

Abstract
The MAESTRI Total Efficient Framework (MTEF) is a recent holistic concept that congregates four complementary dimensions: Efficiency Framework; IoT Platform; Management System and Industrial Symbiosis. MTEF promotes the development of strategies for continuous performance improvement towards a more sustainable manufacturing. The Efficiency Framework supports the integrated assessment of operations efficiency and eco-efficiency, being measured by a new concept: Total Efficiency Index (TEI). The simultaneous assessment of the environmental, economic and efficiency performance of complex production systems is only possible with a digitalized production system, which is aligned with Industry 4.0 paradigm. Thus, with TEI original dashboards and graphical diagram, both static and dynamic assessments of efficiency vs. eco-efficiency can be analyzed. This paper details the fundaments of the Efficiency Framework and TEI, and presents an application case study from the metalworking sector, where the achieved results are discussed for the new concept validation. (C) 2018 The Authors. Published by Elsevier B.V.

2018

Characterizing attentive behavior in intelligent environments

Authors
Duraes, D; Carneiro, D; Jimenez, A; Novais, P;

Publication
NEUROCOMPUTING

Abstract
Learning styles are strongly connected with learning and when it comes to acquiring new knowledge, attention is one the most important mechanisms. The learner's attention affects learning results and can define the success or failure of a student. When students are carrying out learning activities using new technologies, it is extremely important that the teacher has some feedback from the students' work in order to detect potential learning problems at an early stage and then to choose the appropriate teaching methods. In this paper we present a nonintrusive distributed system for monitoring the attention level in students. It is especially suited for classes working at the computer. The presented system is able to provide real-time information about each student as well as information about the class, and make predictions about the best learning style for a student using an ensemble of neural networks. It can be very useful for teachers to identify potentially distracting events and this system might be very useful to the teacher to implement more suited teaching strategies. (C) 2017 Published by Elsevier B.V.

2018

Single-Phase AC-DC-AC Multilevel Converter for Grid Overvoltage Based on an H-Bridge Connected in Series to the Five-Leg Converter

Authors
Queiroz, ADD; Jacobina, CB; Maia, ACN; Melo, VFMB; de Freitas, NB; Carlos, GAD;

Publication
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS

Abstract
In this work, an ac-dc-ac multilevel power converter for grid overvoltage is investigated. The developed configuration is composed of one single-phase ac-dc-ac three-leg module and two H-bridges. One of them is connected to the shared part of the system to generate multilevel voltages at the input and output of the structure, and the other one is connected to the grid side to compensate the grid overvoltage. The converter can be employed in applications with same input and output frequency, such as uninterrupted power supply and unified power quality conditioner without isolation transformer. System model, a space vector pulsewidth modulation strategy to balance the individual dc-link voltages, and an overall control strategy to adjust the grid power factor, the amplitude, and the frequency of the load voltage are presented. The proposed converter is compared in terms of harmonic distortion and semiconductor losses with conventional structures. Simulation and experimental results demonstrate the operation of the proposed topology.

2018

Professional Competence Identification Through Formal Concept Analysis

Authors
Silva, PR; Dias, SM; Brandão, WC; Song, MA; Zárate, LE;

Publication
Enterprise Information Systems - Lecture Notes in Business Information Processing

Abstract

2018

Programming Networked Vehicle Systems using Dolphin - Field Tests at REP'17

Authors
Lima, K; Marques, ERB; Pinto, J; Sousa, JB;

Publication
2018 OCEANS - MTS/IEEE KOBE TECHNO-OCEANS (OTO)

Abstract
The increasing availability and use of autonomous vehicles for real operational scenarios has led to the need for tools that allow human operators to interact with multiple systems effectively, taking into account their capabilities, limitations and environmental constraints. Multiple vehicles, deployed together in order to accomplish a common goal, impose a high burden on a human operator for specifying and executing coordinated behavior, particularly in mixed-initiative systems where humans are part of the control loop. In this paper, we describe experimental field tests for Dolphin, a domain-specific language that allows a single program to define the joint behaviour of multiple vehicles over a network. Using the language, it is possible to accomplish an orchestrated execution of single-vehicle tasks according to several patterns such as sequential, concurrent, or event-based program flow. With this aim, Dolphin has been integrated modularly with a software toolchain for autonomous vehicles developed by Laboratorio de Sistemas e Tecnologia Subaquatica (LSTS). The tests we describe made use of LSTS unmanned underwater vehicles (UUVs) at open sea during the 2017 edition of Rapid Environment Picture (REP), an annual exercise jointly organised by LSTS and the Portuguese Navy.

2018

Preface

Authors
Masci, P; Monahan, R; Prevosto, V;

Publication
Electronic Proceedings in Theoretical Computer Science, EPTCS

Abstract

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