INESCC-DL - Artigos em Livros de Actas
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- On the information provided by uncertainty measures in the classification of remote sensing imagesPublication . Gonçalves, Luisa; Fonte, Cidália C.; Júlio, Eduardo N.B.S.; Caetano, MarioThis paper investigates the potential information provided to the user by the uncertainty measures applied to the possibility distributions associated with the spatial units of an IKONOS satellite image, generated by two fuzzy classifiers, based, respectively, on the Nearest Neighbour Classifier and the Minimum Distance to Means Classifier. The deviation of the geographic unit characteristics from the prototype of the class to which the geographic unit is assigned is evaluated with the Un non-specificity uncertainty measures proposed by [1] and the exaggeration uncertainty measure proposed by [2]. The classifications were evaluated using accuracy and uncertainty indexes to determine their compatibility. Both classifications generated medium to high levels of uncertainty for almost all classes, and the global accuracy indexes computed were 70% for the Nearest Neighbour Classifier and 53% for the Minimum Distance to Means Classifier. The results show that similar conclusions can be obtained with accuracy and uncertainty indexes and the latter, along with the analysis of the possibility distributions, may be used as indicators of the classification performance and may therefore be very useful tools. Since the uncertainty indexes may be computed to all spatial units, the spatial distribution of the uncertainty was also analysed. It's visualization shows that regions where less reliability is expected present a great amount of detail that may be potentially useful to the user.
- Using Uncertainty Information to Combine Soft ClassificationsPublication . Gonçalves, Luisa M. S.; Fonte, Cidália C.; Caetano, MarioThe classification of remote sensing images performed with different classifiers usually produces different results. The aim of this paper is to investigate whether the outputs of different soft classifications may be combined to increase the classification accuracy, using the uncertainty information to choose the best class to assign to each pixel. If there is disagreement between the outputs obtained with the several classifiers, the proposed method selects the class to assign to the pixel choosing the one that presents less uncertainty. The proposed approach was applied to an IKONOS image, which was classified using two supervised soft classifiers, the Multi-layer Perceptron neural network classifier and a fuzzy classifier based on the underlying logic of the Minimum-Distance-to-Means. The overall accuracy of the classification obtained with the combination of both classifications with the proposed methodology was higher than the overall accuracy of the original classifications, which shows that the methodology is promising and may be used to increase classification accuracy.
- Influence of a SVC on AC Arc furnaces harmonics, flicker and unbalance. Measurement and analysis.Publication . Donsión, M. P.; Güemes, J. A.; Oliveira, F.An AC arc furnace is an unbalanced, nonlinear and time varying load, which can cause many problems to power system quality. Different studies on arc furnaces harmonics analysis can be found in the bibliography on the topic; however, it is very difficult obtain an exact model that takes into account all the parameters that have influence on the process, therefore it is necessary to take measurements under different conditions. In this paper we'll present the harmonic distortion, flicker and unbalance results and conclusions on three different measurement campaigns in an iron and steel industry (SNL) with an AC arc furnace of 83 MW (170 TM) with a transformer of 120 MVA connected with a dedicated power line of 220 kV (55 km) to the Carregado Substation, where there are another other branches that connect industrial and domestic consumers.
- A comparison of the vibration characteristics of a rotating machine with a linear and a keyed shaftPublication . Oliveira, F.; Pelaez, G.; Donsion, M. P.This paper presents some results of an ongoing work aimed at studying a number of characteristics of rotating machines and how they are influenced by both constructive features and the way they are driven. The following will present the main results obtained when a simple one-stage inertia turbomachine is built with a linear, cylindrical shaft or, instead, with a shaft that has a small slot such as those used in many mechanical couplings. Experimental results will show some significant differences in the behavior of the machine, both in terms of the orbit and in the resonance frequencies, as well as in the phase and amplitude of mechanical vibrations.
- An Evolutionary Algorithm based on an outranking relation for sorting problemsPublication . Oliveira, Eunice; Antunes, Carlos HenggelerA new approach for using the preferences elicited from a Decision Maker (DM) into the operational framework of an Evolutionary Algorithm (EA) is presented. The preference representation is achieved using the parameters and principles of the ELECTRE TRI method devoted to the sorting problem. The outranking relation is used to replace the non-dominance relation in the usual operators in the EA (crossover, mutation and selection operator). The aim of this approach is to focus the search on the region of interest defined by the DM's preferences and consequently restrict the number of solutions in the Pareto-optimal front to be subject to further screening. This aspect is particularly important when dealing with problems that lead to a large number of non-dominated solutions.
- A hybrid multi-objective GRASP+SA algorithm with incorporation of preferencesPublication . Oliveira, Eunice; Antunes, Carlos Henggeler; Gomes, ÁlvaroA hybrid multi-objective approach based on GRASP (Greedy Randomized Adaptive Search Procedure) and SA (Simulated Annealing) meta-heuristics is proposed to provide decision support in a direct load control problem in electricity distribution networks. The main contributions of this paper are new techniques for the incorporation of preferences in these meta-heuristics and their hybridization. Preferences are included in the construction phase of multi-objective GRASP, in SA, as well as in the selection of solutions that go to the next generation, with the aim to obtain solutions more in accordance with the preferences elicited from a decision maker. The incorporation of preferences is made operational using the principles of the ELECTRE TRI method, which is based on the exploitation of an outranking relation in the framework of the sorting problem.
- Complexity Analysis of a Business Process Automation: Case Study on a Healthcare OrganizationPublication . Martinho, Ricardo; Rijo, Rui, Rui Pedro Charters Lopes; Nunes, AnaHealthcare organizations have been struggling to get Business Process Management (BPM) and associated Information and Communication Technologies (ICT) properly aligned to improve their patients' service and quality of care. Nevertheless, the highly structured nature of larger organizations such as hospitals hampers this alignment, and commonly ICT is applied to isolated tasks or fragments of processes. In this paper, we present and discuss the results, in terms of complexity, of the introduction of a new scheduling system within the medical appointment and exam business processes of a large hospital. During the case study, we began by modelling the processes using the Business Process Modelling and Notation (BPMN) standard. We then used abstract metrics to compare the complexity between old (before the introduction of the scheduling system) and new processes, and interpreted the obtained results. Finally, we derived important conclusions that will help guide us in further business process optimization endeavors.
- Use of Web Based Meters to Improve Energy Efficiency and Power Quality in BuildingsPublication . Moreira, Licínio; Leitão, Sérgio; Vale, Zita; Galvão, JoãoDuring the work conducted, several buildings were analysed, in terms of energy efficiency and power quality. Two case studies are here presented: an educational building and a museum. Most of the studies were conducted recurring to traditional measurement equipment, forcing the person to travel to the site to install equipment and every time he wanted to collect data. But one of the case studies, the museum, comprised the development of an analyser (hardware and software) able to measure electric energy, temperature and humidity. This analyser has the capability to register values on a database available in the internet and issue warnings to the building manager. This allows real-time information, supporting some energy efficiency actions. The objective is to improve this model and expand its use for several buildings, providing savings in terms of time and other resources, taking advantage of cloud-based systems.
- Plataforma Unidose para LaresPublication . Lopes, David Ferreira; Costa, Nuno; Pereira, AntónioA esperança média de vida tem aumentado devido às melhorias que se têm verificado nos serviços de saúde e pela evolução da medicina levando a um envelhecimento da população mundial. As famílias com vidas cada vez mais preenchidas e atarefadas não conseguem prestar o auxílio e o apoio necessário aos idosos levando estes a frequentar cada vez mais Lares e Centros de dia para idosos. Isto leva a que exista uma enorme responsabilidade pela saúde dos idosos por parte dos lares que os acolhem sobretudo ao nível da medicação, delegando grandes responsabilidades a funcionários da instituição. Os funcionários como seres humanos erram, podem errar, haver negligência ao darem a toma de medicação aos idosos. Cada vez mais os idosos têm menos capacidades financeiras devido a situação económica do país e alguns acabam mesmo por ter que deixar a medicação para sobreviverem. A Plataforma Unidose para Lares (PUL) é uma solução para tentar contrariar ou resolver estes problemas. É possível utilizar o sistema Unidose, que permite a venda dos comprimidos à unidade torando-se mais económico e também fazendo a prevenção da toma de medicamentos para não permitir negligencias nem faltas de tomas. Com a utilização da plataforma as vidas dos idosos e funcionários de lares vão ficar mais calmas, com menos preocupações, melhorando assim a qualidade de vida destes.
- eServices - Service Platform for Pervasive Elderly CarePublication . Marcelino, Isabel; Laza, Rosalía; Domingues, Patrício; Gómez-Meire, Silvana; Pereira, AntónioIn this paper, we present a solution to improve elderly’s quality of life. eServices – Service platform for pervasive elderly care was designed to aggregate several services developed to meet senior population’s needs. It monitors basic life signs, environment variables and uses personal location technology. Besides sensor services, eServices solution contains digital services align with emotional and social care needs. Due to target population specifications, eServices was designed to be as simple and accessible as possible in order to remove technological barriers. One of eServices major features is to detect imminent danger situations, act accordingly. It also collects the data from the sensors, location routines and from the interactions between the elderlies and the provided services to detect behavior deviations in order to act preventively. The platform was tested by seniors in real scenario. The experimental results demonstrated that the proposed platform was well accepted and easy to use by seniors, which demonstrated enthusiasm and interest in daily bases use.