1,031 research outputs found

    Can fire spread simulations contribute to support decisions in a fire suppression context ? An evaluation using MaxEnt, FARSITE and satellite active fire data

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    Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia / ULThis work is of an exploratory nature and describes and evaluates a method to simulate fire spread which, in an operational context, has the potential to be used as a decision-support tool for fire management and suppression. The use of fire spread models has, for the most part, followed a deterministic approach, which does not account for predictions uncertainty. However, fire spread models are subject to assumptions and limitations that inherently produce errors during simulations and so should be integrated in the simulations themselves. For that matter uncertainty was propagated through Farsite fire behavior model by randomly defining 100 different independent combinations of some of the most important input variables. The simulations were run with three different fuel maps, one standardized and two customized. For the evaluation of the fire spread predictions a qualitative and a quantitative analysis were made. Both analyses used MaxEnt derived reference perimeters, and active fire data was used on the qualitative analyses to add temporal depth to the evaluation. Results showed that uncertainties in wind speed and direction, location of ignitions (spatial and temporal), fuel model assignment and typology may have major impact on prediction accuracy. Overall, fuel models presented better results when compared with the standard model and generally showed higher Kappa and burned class agreement values and lower omission errors. This thesis suggests that this method has major potential to optimize fuel management practices, especially if simulations are run with fuel maps derived Portuguese landcover mapsN/

    Long-term biosignals visualization and processing

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    Thesis submitted in the fulfillment of the requirements for the Degree of Master in Biomedical EngineeringLong-term biosignals acquisitions are an important source of information about the patients’state and its evolution. However, long-term biosignals monitoring involves managing extremely large datasets, which makes signal visualization and processing a complex task. To overcome these problems, a new data structure to manage long-term biosignals was developed. Based on this new data structure, dedicated tools for long-term biosignals visualization and processing were implemented. A multilevel visualization tool for any type of biosignals, based on subsampling is presented, focused on four representative signal parameters (mean, maximum, minimum and standard deviation error). The visualization tool enables an overview of the entire signal and a more detailed visualization in specific parts which we want to highlight, allowing an user friendly interaction that leads to an easier signal exploring. The ”map” and ”reduce” concept is also exposed for long-term biosignal processing. A processing tool (ECG peak detection) was adapted for long-term biosignals. In order to test the developed algorithm, long-term biosignals acquisitions (approximately 8 hours each) were carried out. The visualization tool has proven to be faster than the standard methods, allowing a fast navigation over the different visualization levels of biosignals. Regarding the developed processing algorithm, it detected the peaks of long-term ECG signals with fewer time consuming than the nonparalell processing algorithm. The non-specific characteristics of the new data structure, visualization tool and the speed improvement in signal processing introduced by these algorithms makes them powerful tools for long-term biosignals visualization and processing

    Generalized software application for operation of a 3D vehicle in air, water and land

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    The unmanned vehicles (UV) and its applications are growing exponentially. Using the radio control is the most common way to control these types of vehicles for being a simple and cheap method to control an UV. However, it doesn’t have a visual interface that allows the user to see the vehicle’s information such as battery status, speed, distance, geolocation, etc. To deal with this problem, some mobile and desktop applications have been developed. To communicate between the control device and the vehicle, dongles are commonly used to establish the connection using radio, Bluetooth or Wi-Fi. In most cases, these technologies don’t allow the user to control at long distances, Beyond Line Of-Sight (BLOS), and these applications are focused to use mostly on multi-copters, and most of the times, they only allow to connect a vehicle at a time. The purpose of this dissertation is to study the reliability of an application able to control multiple types of vehicles, such as aerial, land and water vehicles. This application allows the user to connect multiple vehicles at the same time using a single device, easily change the vehicle assigned to control, by using mobile networks to perform the communication between the developed application and the vehicle. In this way, it will be possible to connect a 3D – hybrid vehicle, which is a vehicle capable of moving in water, land and air environments, allowing the user to control the vehicle at long distances with video feedback. To achieve the purpose of this dissertation, it was developed an Android application to allow controlling the vehicle by using mobile networks to communicate. In the vehicle, besides the common electronics used in an unmanned vehicle (ESC’s, motors, batteries, controller board, etc.), it will be used a Raspberry Pi 2 model B with a 3rd Generation (3G) and 4th Generation (4G) dongle that will connect the vehicle to the internet, routing the messages coming from the controller board placed in the vehicle to the mobile application. It was also developed a server application to do the user management and exchange the messages coming from both platforms: vehicle and application.Os veículos não tripulados e as suas aplicações estão em forte crescimento. O uso de rádio controlo é a maneira mais comum de controlar estes tipos de veículos, sendo o método mais barato e simples de controlar um veículo não tripulado. Contudo, não têm uma interface visual que permita ao utilizador ver as informações do veículo, tais como o nível da bateria, a velocidade, distância, geolocalização, entre outros. Para ajudar com este problema, têm sido desenvolvidas algumas aplicações para dispositivos móveis e computadores, que permitem controlar e monitorizar este tipo de veículos. Para estabelecer a comunicação entre o dispositivo de controlo e o veículo, são frequentemente usados dongles para comunicar por rádio, Bluetooth ou Wi-Fi. Na maioria dos casos, estas tecnologias não possibilitam ao utilizador o controlo a longas distâncias, para além da linha de vista, e costumam ser focadas para o uso em multicopteros, possibilitando, na maioria dos casos, a ligação de um único veículo. O âmbito desta dissertação pretende estudar e desenvolver uma aplicação com elevada fiabilidade, capaz de controlar vários tipos de veículos, nomeadamente, veículos aéreos, terrestres e aquáticos. Esta aplicação irá permitir a ligação a vários veículos ao mesmo tempo, trocar facilmente o veiculo a controlar, recorrendo aos sistemas de comunicação móveis celulares, 3ª geração (3G ) e 4ª geração (4G) para garantir a comunicação entre a aplicação desenvolvida e o veículo não tripulado. Seguindo estes princípios, é possível controlar um veículo 3D hibrido (em modo de ar, terra e mar). Esta permite ao utilizador controlar o veículo a longas distâncias com o uso de uma transmissão de vídeo. Para alcançar o objetivo desta dissertação foi desenvolvida uma aplicação Android para possibilitar o controlo recorrendo às redes móveis celulares. No veículo, além da eletrónica habitual, para um veículo não tripulado (motores, ESC’s, baterias, etc.), será também utilizado um Raspberry Pi 2 modelo B com um dongle 3G/4G que liga o veículo, redirecionando as mensagens vindas da placa de controlo para a aplicação móvel. Para a comunicação entre a aplicação e o veículo foi também desenvolvida uma aplicação instalada no servidor que é responsável pela gestão de utilizadores e pela troca de mensagens vindas de ambas as plataformas: veículo e aplicação

    LSTM Models to Support the Selective Antibiotic Treatment Strategy of Dairy Cows in the Dry Period

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    Dissertation presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Data ScienceUdder inflammation, known as mastitis, is the most significant disease of dairy cows worldwide, invoking substantial economic losses. The current common strategy to reduce this problem is the prophylactic administration of antibiotics treatment of cows during their dry period. Paradoxically, the indiscriminate use of antibiotics in animals and humans has been the leading cause of antimicrobial resistance, a concern in several public health organizations. In light of these assumptions, at the beginning of 2022, the European Union made it illegal to routinely administer antibiotics on farms, with Regulation 2019/6 of 11 December 2018. Considering this new scenario, the objective of this study was to produce a model that supports the decisions of veterinarians when administering antibiotics in the dry period of dairy cows. Deep learning models were used, namely LSTM layers that operate with dynamic features from milk recordings and a dense layer that uses static features. Two approaches were chosen to deal with this problem. The first is based on a binary classification model that considers the occurrence of mastitis within 60 days after calving. The second approach was a multiclass classification model based on veterinary expert judgment. In each approach, three models were implemented, a Vanilla LSTM, a Stacked LSTM, and a Stacked LSTM with a dense layer working in parallel. The best performances from binary and multiclass approaches were 65% and 84% accuracy, respectively. It was possible to conclude that the models of the multiclass classification approach had better performance than the other classification. The capture of long- and short-term dependencies in the LSTM models, especially with the combination of static features, obtained promising results, which will undoubtedly contribute to producing a machine learning system with a prompt and affordable response, allowing for a reduction in the administration of antibiotics in dairy cows to the strictly necessary

    Channel equalization based on decision trees

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    This paper analyzes the application of decision trees to the problem of communication channel equalization. Decision trees are interesting structures because they are nonlinear and relatively simple from a computational standpoint. They are tested for channel models that give rise to classification tasks of different complexity and compared to the Bayesian equalizer and the Wiener linear equalizer. The results are quite encouraging, as they show that the tree-based equalizer reaches, in many cases, a performance similar to that of the Bayesian filter at a lower computational cost351150161CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ305621/2015-7; 134058/2016-

    Exploring risk dynamics in corporate bonds : a study of effective and Macaulay durations

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    This dissertation examines the effect of firms’ credit risk on interest rate risk using two real-world corporate bond portfolios in December 2022, one with low credit risk and the other with high credit risk. This is done by comparing the Macaulay duration with the effective duration resulting from the application of Leland and Toft (1996) structural credit risk model. It was found on average a Macaulay duration of 4.24 years versus an effective duration of 2.92 years for the high-risk portfolio, while the low-risk portfolio displayed a Macaulay duration of 9.04 years in contrast to an effective duration of 7.47 years. The difference between the Macaulay and effective durations highlights the limitations of traditional risk management techniques, such as immunization, which often do not take into account the relation between interest rates and credit risk.Esta dissertação examina o efeito do risco de crédito das empresas sobre o risco da taxa de juro, utilizando dois portfólios de títulos corporativos reais em dezembro de 2022, um com baixo risco de crédito e outro com alto risco de crédito. Isto é conseguido comparando a duração de Macaulay com a duração efetiva resultante da aplicação do modelo de risco de crédito estrutural de Leland e Toft (1996). Os nossos resultados de pesquisa revelaram uma duração média de Macaulay de 4,24 anos contra uma duração efetiva de 2,92 anos para o portfólio de alto risco, enquanto o portfólio de baixo risco apresentou uma duração de Macaulay de 9,04 anos em contraste com uma duração efetiva de 7,47 anos. Esta diferença entre as durações de Macaulay e efetiva destaca as limitações das técnicas tradicionais de gestão de risco, como a imunização, que muitas vezes não levam em consideração a relação entre as taxas de juro e o risco de crédito

    Gender-Affirming Hormone Therapy: Physical and Sociopsychological Effects, Impact and Satisfaction

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    Background Gender dysphoria treatment includes gender-affirming hormone therapy (GAHT). Studies are still lacking on how to characterize its effects and impact on transgender people's lives more effectively. Aim To study the physical and psychological effects of GAHT on transgender individuals, assess its impact on their lives, and rate their overall satisfaction. Methods Participants (n = 114; ages 18-62 years; median age 24.0 (21.0 - 33.0) years) included transgender adults residing in Portugal who were undergoing or had undergone hormonal therapy for at least one uninterrupted year. Participants completed an original questionnaire. For most items, an ordinal Likert-style scale ranging from 0 (worst result) to 6 (best result) was used. Descriptive statistics and non-parametric tests, including Pearson's chi-squared test, Wilcoxon signed-rank test, and Mann-Whitney U test were used to analyze categorical and continuous variables, with a significance level set at 0.05. Outcomes The outcomes included desired physical changes rating (perception and satisfaction with changes); side effects of GAHT; the sociopsychological impact of GAHT (on self-esteem, body image, psychological wellbeing, social and family relations); overall satisfaction (with treatment results and medical follow-up). Results The changes classified as the most perceptible in those undergoing masculinizing treatment (Group M) were amenorrhea (6 (5.0-6.0) points) and clitoris enlargement (6 (5.0-6.0) points). These were also the ones rated as the most satisfactory (6 (6.0-6.0) points for amenorrhea and 6 (4.0-6.0) points for clitoris enlargement). On those undergoing feminizing therapy (Group F), the alteration voted as the most perceptible was sperm production decrease (6 (2.0-6.0) points), and the ones classified as the most satisfactory were sperm production decrease (6 (4.0-6.0) points) and spontaneous erections decrease (6 (5.0-6.0) points). Side effects were reported by 89.7% of Group M (mood swings were the most common) and 96.3% of Group F (decreased libido was the most frequent). The sociopsychological impact of hormonal treatment was significantly positive in all analyzed variables (p<0.001). Overall satisfaction with treatment results and medical follow-up were rated with 5 points and 4.5 points, respectively. Clinical implications This study provides clinicians with more evidence that GAHT may improve the physical, psychological and social health of transgender people seeking medical transition. Strengths and limitations The strengths of the current study include a high participant count relative to the target population, the acquisition of data on previously unexplored variables, and the significance of being one of the few investigations of its kind conducted in Portugal. However, the study has limitations, including differences in participant characteristics, a small sample size for some variables, potential bias due to the retrospective nature of the study, individualized treatment regimens, and the inclusion of participants from different countries, which limit the generalization of the results. Conclusions This study provides further evidence that GAHT is effective, and that its physical effects are satisfactory while resulting in mostly non-severe nor life-threatening side effects. GAHT is an important therapy in gender dysphoria and has consistent results in improving numerous sociopsychological variables.info:eu-repo/semantics/publishedVersio

    Gestão do desporto na Câmara Municipal de Leiria

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    O presente relatório surge no âmbito do estágio realizado no 2º ano do Mestrado em Gestão do Desporto da Faculdade de Motricidade Humana da Universidade de Lisboa e assenta sob a forma de relato e respetiva reflexão das atividades desenvolvidas. O estágio foi realizado na Divisão de Desporto e Juventude (DIDJ) da Câmara Municipal de Leiria (CML) e teve como finalidade compreender o contexto legal e institucional do Município de Leiria, assim como acompanhar os processos de organização e gestão do desporto. A CML tem diversas funções no âmbito do desporto, nomeadamente na gestão das instalações públicas de desporto, no apoio ao associativismo de desporto e nos eventos e espetáculos de desporto. Este relatório compreende vários capítulos que abordam na totalidade as atividades e o processo de estágio, com especial atenção nas atividades consideradas mais importantes no processo formativo, nos eventos e no projeto apresentado: “Mobilidade Ativa e Sustentável: Educar e Praticar”. O estágio foi enriquecedor e contribuiu para a consolidação de conhecimentos e aquisição de novas competências nas áreas da gestão do desporto.The present report concerns the internship conducted in the 2nd year of Sports Management Master’s Degree, Faculty of Human Kinetics of Lisbon University and it offers a description of and a reflection on the carried activities. The purpose of this internship was to comprehend the legal and institutional context of the Sport and Youth Division of Leiria’s City Hall as well as to follow the organizational processes underlying sports management. Leiria’s City Hall has several roles in the sports department, namely in public sports facilities management, in the support of sports associations and also in the promotion of shows and sports events. This report contains chapters that address the numerous activities carried on this internship, with further attention to a few considered most important to the formative process and during events, as well relevant to the project: “Active mobility: to educate and to practice”. The experience was enriching and contributed to the consolidation of knowledge and to the acquisition of new competencies in sports management

    Protecção de sistemas de energia eólica contra descargas eléctricas atmosféricas.

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    Esta tese incide sobre o tema da protecção de sistemas de energia eólica contra descargas eléctricas atmosféricas. Foram disponibilizados, para o propósito desta tese, os registos dos primeiros cinco anos de actividade do sistema automático de detecção de trovoadas do Instituto de Meteorologia. Novos resultados referentes à caracterização da actividade ceráunica sobre o território continental Português são apresentados. É elaborada uma modelação matemática adequada ao estudo da propagação das sobretensões transitórias causadas por DEA. Um novo modelo sobre a protecção de sistemas de energia eólica foi desenvolvido e sujeito a simulação com o programa de computador EMTP-RV. Os resultados da simulação com o EMTP-RV são apresentados e discutidos. Ainda, foi desenvolvido um novo programa de computador, LPS 2008. O LPS 2008 permite efectuar a análise de risco de danos causados por DEA de acordo com a norma internacional IEC 62305-2. O LPS 2008 simula o modelo da esfera rolante proposto pela IEC 62305, identificando os pontos vulneráveis de uma estrutura e permitindo ao projectista conceber um sistema de protecção eficaz
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