Real earnings management : state-owned vs non-state-owned companies

Mestrado em Contabilidade, Fiscalidade e Finanças EmpresariaisO propósito deste estudo é analisar o grau de gestão de resultados com base em operações reais nas empresas estatais e não estatais, tendo em consideração os potênciais efeitos de períodos de crise. A amostra é composta de 15.147 empresas, 995 das quais estatais, de 22 países euopeus, 8 setores de indústria e durante os anos de 2008 a 2017. De acordo com a metodologia desenvolvida por Roychowdhury (2006), os resultados demonstram que as empresas privadas praticam mais gestão de resultados com base em operações reais, quando comparadas com as empresas não estatais. Adicionalmente, a dimensão, o endividamento e as oportunidades de crescimento de uma empresa foram vistas como fatores de influencia na pratica de gestão de resultados. Finalmente, os resultados demonstram que os períodos de crise têm uma influência positiva na prática de gestão de resultados.The study has the purpose of analysing the degree of real earnings management in state and non-state-owned firms, taking into account the potential effects of crisis periods. The sample is composed of 15.147 companies, 995 state-owned and 14.152 non-state-owned, from 22 European countries and 8 industry sectors, from the years of 2008 to 2017. Following the Roychowdhury (2006) methodology the results show that state-owned firms have a higher degree of real earnings management when compared with non-state-owned. Additionally, the size, debt and growth opportunities were seen to influence the practice of real earnings management. Finally, the results show that the crisis periods have a positive influence on the practice of real earnings management.info:eu-repo/semantics/publishedVersio

Forecasting tourism demand for Lisbon’s region through a data mining approach

Ricardo, H., Ivo, G., & Costa, A. C. (2018). Forecasting tourism demand for Lisbon’s region through a data mining approach. In M. B. Nunes, P. Isaías, & P. Powell (Eds.), Proceedings of the 11th IADIS International Conference Information Systems 2018 (pp. 58-66). IADIS Press. ISBN: 978-989-8533-74-6Tourism stakeholders such as the government, passenger transport companies, accommodation establishments, restaurants, recreational businesses, among others, rely on tourism demand indicators’ forecasts to make decisions. Most of tourism demand forecasting models are time-series and econometric based. Machine learning methods are emerging and have been proved to be quite suitable for non-linear modelling. These methods are part of an interdisciplinary field named “Data Mining” which is known by the process of knowledge discovery in databases (KDD). The core drive of this work is to enhance the available public sources of tourism forecast information and to contribute to the tourism stakeholders’ strategy in Portugal. More specifically, a multivariate model to forecast international tourism demand was developed through a Data Mining approach, which assessed models derived by Regression Trees (Random Forests), Artificial Neural Networks and, Support Vector Machines (SVM). The model development was constrained to machine learning methods, publicly available data, and minimum data assumptions. The forecasted demand variable was the nights spent at tourist accommodation establishments in Lisbon’s region, one of the country’s main foreign tourist destinations. The objectives were achieved, as the selected model (SMOReg, support vector regression) was successful in generalization capability. The accuracy of the produced forecasts provides some evidence of the reliability of the proposed model. If institutions and decision makers have information regarding the evolution of the explanatory variables used in this model, the impact on Lisbon’s tourism demand can be assessed, even in case of an emerging recession, as shown using three future plausible scenarios.publishersversionpublishe

A study with the semantic learning machine

Lapa, P., Rundo, L., Gonçalves, I., & Castelli, M. (2019). Enhancing classification performance of convolutional neural networks for prostate cancer detection on magnetic resonance images: A study with the semantic learning machine. In GECCO 2019 : Proceedings of the 2019 Genetic and Evolutionary Computation Conference Companion (pp. 381-382). (GECCO 2019 Companion - Proceedings of the 2019 Genetic and Evolutionary Computation Conference Companion). Association for Computing Machinery, Inc. https://doi.org/10.1145/3319619.3322035 --- This work was partially supported by projects UID/MULTI/00308/2019 and by the European Regional Development Fund through the COMPETE 2020 Programme, FCT - Portuguese Foundation for Science and Technology and Regional Operational Program of the Center Region (CENTRO2020) within project MAnAGER (POCI-01-0145-FEDER-028040). This work was also partially supported by national funds through FCT (Fundação para a Ciência e a Tecnologia) under project DSAIPA/DS/0022/2018 (GADgET).Prostate cancer (PCa) is the most common oncological disease in Western men. Even though a significant effort has been carried out by the scientific community, accurate and reliable automated PCa detection methods are still a compelling issue. In this clinical scenario, high-resolution multiparametric Magnetic Resonance Imaging (MRI) is becoming the most used modality, also enabling quantitative studies. Recently, deep learning techniques have achieved outstanding results in prostate MRI analysis tasks, in particular with regard to image classification. This paper studies the feasibility of using the Semantic Learning Machine (SLM) neuroevolution algorithm to replace the fully-connected architecture commonly used in the last layers of Convolutional Neural Networks (CNNs). The experimental phase considered the PROSTATEx dataset composed of multispectral MRI sequences. The achieved results show that, on the same non-contrast-enhanced MRI series, SLM outperforms with statistical significance a state-of-the-art CNN trained with backpropagation. The SLM performance is achieved without pre-training the underlying CNN with backpropagation. Furthermore, on average the SLM training time is approximately 14 times faster than the backpropagation-based approach.authorsversionpublishe

Bibliotecas da Administração Pública: pensar o futuro - contributos de um utilizador

Comunicação apresentada no Ciclo de Debates "Pensar a Administração Pública", 11.ª Sessão - Bibliotecas da Administração Pública: pensar o futuro, organizada pelo INA, em Lisboa a 12 de fevereiro de 201

Real-world deployment of low-cost indoor positioning systems for industrial applications

The deployment of an Indoor Position System (IPS) in the real-world raised many challenges, such as installation of infrastructure, the calibration process or modelling of the building's floor plan. For Wi-Fi-based IPSs, deployments often require a laborious and time-consuming site survey to build a Radio Map (RM), which tends to become outdated over time due to several factors. In this paper, we evaluate different deployment methods of a Wi-Fi-based IPS in an industrial environment. The proposed solution works in scenarios with different space restrictions and automatically builds a RM using industrial vehicles in operation. Localization and tracking of industrial vehicles, equipped with low-cost sensors, is achieved with a particle filter, which combines Wi-Fi measurements with heading and displacement data. This allows to automatically annotate and add new samples to a RM, named vehicle Radio Map (vRM), without human intervention. In industrial environments, vRMs can be used with Wi-Fi fingerprinting to locate human operators, industrial vehicles, or other assets, allowing to improve logistics, monitoring of operations, and safety of operators. Experiments in an industrial building show that the proposed solution is capable of automatically building a high-quality vRM in different scenarios, i.e., considering a complete floor plan, a partial floor plan or without a floor plan. Obtained results revealed that vRMs can be used in Wi-Fi fingerprinting with better accuracy than a traditional RM. Sub-meter accuracies were obtained for an industrial vehicle prototype after deployment in a real building.This work was supported in part by the Fundacao para a Ciencia e Tecnologia-FCT through the Research and Development Units Project Scope under Grant UIDB/00319/2020 and in part by the Ph.D. Fellowship under Grant PD/BD/137401/2018. The associate editor coordinating the review of this article and approving it for publication was Prof. Masanori Sugimoto

An adaptive and modular framework for evolving deep neural networks

Santos, F. J. J. B., Gonçalves, I., & Castelli, M. (2023). Neuroevolution with box mutation: An adaptive and modular framework for evolving deep neural networks. Applied Soft Computing, 147(November), 1-15. [110767]. https://doi.org/10.1016/j.asoc.2023.110767 --- Funding: This work is funded by national funds through the FCT - Foundation for Science and Technology, I.P., within the scope of the projects CISUC - UID/CEC/00326/2020, UIDB/04152/2020 - Centro de Investigação em Gestão de Informação (MagIC)/NOVA IMS, and by European Social Fund, through the Regional Operational Program Centro 2020 .The pursuit of self-evolving neural networks has driven the emerging field of Evolutionary Deep Learning, which combines the strengths of Deep Learning and Evolutionary Computation. This work presents a novel method for evolving deep neural networks by adapting the principles of Geometric Semantic Genetic Programming, a subfield of Genetic Programming, and Semantic Learning Machine. Our approach integrates evolution seamlessly through natural selection with the optimization power of backpropagation in deep learning, enabling the incremental growth of neural networks’ neurons across generations. By evolving neural networks that achieve nearly 89% accuracy on the CIFAR-10 dataset with relatively few parameters, our method demonstrates remarkable efficiency, evolving in GPU minutes compared to the field standard of GPU days.publishersversionpublishe

Desenho da figura humana : perspectiva histórica e recursos didáticos para o ensino secundário

Relatório da Prática de Ensino Supervisionada, Mestrado em Ensino de Artes Visuais, Universidade de Lisboa, Instituto de Educação, 2018O presente relatório partiu de uma intervenção em sala de aula, com a turma I do 11° ano, do curso científico-humanístico de Artes-Visuais, da Escola Secundária da Ramada (Odivelas), no âmbito da disciplina de Desenho A. Esta intervenção foi desenvolvida no ano lectivo de 2017/2018 e teve a duração de quinze aulas de noventa minutos, onde se explorou o tema: Desenho da figura humana, através de uma breve contextualização histórica sobre a evolução dos cânones de representação da figura humana e, um conjunto de cinco de unidades de trabalho que, de certa forma incidiram sobre uma abordagem mimética do ensino e aprendizagem do desenho. Ao longo do processo de investigação, tomaram-se como principais objectos de estudo, em primeiro lugar a análise dos actuais programas curriculares de Desenho A e as provas de exame nacional, em segundo lugar a planificação de uma unidade didáctica, em seguida o desenvolvimento de recursos didácticos, bem como a construção de instrumentos de avaliação e por ultimo a análise e reflexão sobre os principais desafios vivenciados ao longo da prática de ensino supervisionada.This report was based in a classroom intervention, with class I of the 11° grade of the Scientific-Humanistic course in Visual Arts, of Escola Secundária da Ramada (Odivelas), within the discipline of Drawing A. This intervention, developed in the school year of 2017/2018, lasted for fifteen classes of ninety-minutes, where the theme: Drawing of the Human Figure, was explored through a brief historical context on the evolution of the canons of representation of the human figure, through a set of five units of work that, in a certain way, focused on a mimetic approach to the teaching and learning of drawing. Throughout the research process, the main subjects of study were: the analysis of the current curricula of Drawing for secondary schools, as well as the drawing final exams; the planning of a didactic unit; the development of the didactic resources; the construction of evaluation instruments and, finally, the analysis and reflection on the challenges experienced during teaching practice

Emboli detection in middle cerebral artery using continuous wavelet transform

Dissertação de mest., Engenharia Eletrónica e Telecomunicações, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2011Doppler ultrasound is a common non-invasive technique for data acquisition for assistance in clinical analysis and diagnosis. Amongst the clinical applications to blood flow is the detection and characterization of emboli. In this context it was made a comparative study between spectral estimation methods in detection of embolic events in middle cerebral artery blood flow signal. The comparison is made between the Short-Time Fourier Transform and the Continuous Wavelet Transform, whereas the former is the classical and widely discussed method and the latter appears as promising alternative given the known characteristics, such as for non-stationary signal processing. To the signals studied, generated using a simulator, it were added simulated embolic events with known characteristics, like duration, localization and power. The classical method was configured in order to obtain reference results for comparison, whereas the alternative method studied was used with multiple configurations, enabling a richer study on the parameters variation. The analysis to the results obtained for each method was made in terms of false negatives, false positives and sensitivity. The results show that CWT, presented as alternative methods, allows a better embolic events detection rate than STFT, the classical method. All CWT config- urations studied demonstrate better results than STFT. Differences in the results for CWT allow to draw conclusions about the best configuration, among the ones studied, for results optimization, being that the configuration based on Mexican Hat is the one which presents overall better results

HOPE+ : dispositivos móveis na avaliação de doentes em enfermagem

Mestrado em Engenharia de Computadores e TelemáticaA prática de cuidados de enfermagem é iminentemente móvel e comporta necessidades de documentação substanciais. No entanto, os sistemas de informação de suporte raramente estão aptos para a introdução de dados junto do ponto de tratamento, sendo essa tarefa protelada para um momento posterior. A evolução dos dispositivos de computação móvel, a que está associado o desenvolvimento das capacidades para operação em rede sem fios, potencia novas formas de os utilizar na prestação de cuidados de enfermagem. Esses dispositivos podem agora ser utilizados para estender os sistemas de informação até junto do ponto de tratamento. Para além disso, o paradigma móvel e as capacidades emergentes introduzem novas possibilidades, tais como a captura de imagens e a utilização de ecrãs tácteis. Nesta dissertação, desenvolvemos um sistema de informação integrado para apoiar o registo da avaliação de doentes em enfermagem, designado HOPE+. Este sistema surge da evolução de um projecto anterior, o sistema HOPE, e acrescenta novas funcionalidades e uma usabilidade melhorada. O HOPE+ permite agora a introdução intercalada de várias avaliações, adequando-se melhor ao trabalho do enfermeiro. O HOPE+ facilita também o acompanhamento ao longo do tempo da evolução de alterações na integridade cutânea dos doentes, através da aquisição de imagens, recorrendo à câmara do dispositivo móvel. O enfermeiro tem ainda ao seu dispor, através de uma aplicação Web, ferramentas para análise das imagens, incluindo a sua medição e cálculo de áreas. O sistema encontra-se completo e apto para ser integrado nos sistemas de informação hospitalares, embora careça de testes de aceitação adicionais em ambientes de produção. ABSTRACT: The practice of nursing care services is imminently mobile and holds substantial documentation needs. Yet the information support systems rarely are suited to data insertion by the treatment point, being this task protracted to a posterior moment. The evolution of mobile computing devices and the associated development of wireless capable operations provide new ways of using these in nursing care. These devices can now be used to extend the information systems to the treatment point. Besides that, the mobile paradigm and the emergent capacities introduce new possibilities, like the picture capture and the utilization of touch screens. In this dissertation is developed an integrated information system to support the evaluation registry of nursing patients, designated HOPE+. This system appears from the evolution of a preceding project, the HOPE system, and adds new functionalities and a better usability. The HOPE+ now permits the intercalated introduction of several evaluations, suiting better in the nurse workflow. The HOPE+ also facilitates the monitoring of the evolution of skin integrity changes of patients through the time, with the acquisition of pictures recurring to the mobile device camera. The nurse also has at their disposal, through a Web application, tools to analyze pictures, including the measure and area calculation. The system is now complete and able to be integrated in the hospital information systems, yet lacks of additional acceptance test in the production environment