Scaling human-induced pressures to population level impacts in the marine environment : implementation of the prototype CUMULEO-RAM model

This document describes the implementation of a prototype of the CUMULEO-RAM model in a case study of the Wadden Sea and the Dutch North Sea coastal zone. The prototype is designed to quantify pressures of human activities in the marine environment and translate those pressures to (potential) effects on ecosystem indicators. The prototype was developed for the Netherlands Environmental Assessment Agency (PBL) in order to assess its potential use in strategic management decisions. The implemented prototype scales impacts from human activities to population relevant indicators, although actual population size and distribution are not determined. Focus for future work should be on expansion of the list of included human activities and pressures and not so much to attempt to incorporate population dynamics. The strength of the approach is in the transparency, it can be relatively easily understood. It combines spatial data to get insight in effects on survival and reproduction. The simplicity makes adjustments and extensions uncomplicated. The visual aspects combined with the speed of the calculations makes it a powerful tool to support discussions with experts, and it can guide or focus future research

Performance evaluation of different machine learning methods applied on churn database

The growth of data and its storage is becoming more and more important every day. However, occasionally this information is gathered but never used, or perhaps it is improperly gathered, making the extraction of the insides difficult. As a result, while beginning any project, choosing the analysis method is just as crucial as choosing the design of the data collection strategy. Most of the time, we only focus on the analysis of the data and do not consider how it was gathered or whether the fields were actually valuable or just added noise to what we were searching for. For this reason, a trustworthy data set has been chosen for this project. The data came from a telecom company, which, like other modern businesses, collects a lot of data. However, in this case, the data was published on the machine learning web competition Kaggle, where participants competed to build the best model to predict consumer behaviour. One of the key considerations in optimizing any organization's income is preventing customer churn. It happens when customers quit utilizing a company's goods or services, and is also referred to as customer attrition. The main goal of this master's thesis is to analyse a Churn database and categorise the clients in order to determine whether they are likely to leave the company. To do this, two machine learning techniques will be used in the current document. Extreme Gradient Boosting and Random Forest. In order to achieve high performance, the Random Forest (RF) method creates a large number of low-performance models and combines them. In this case, the lower-performance method is called Decision Tree, so it will be explained in more detail in the following document. Similar work is done by eXtreme Gradient Boosting (XGB), although it builds new models based on earlier findings. Both are quite effective predictor models, even with unbalanced data, as will be demonstrated in the next document. This adds another level of complexity that the algorithms must overcome to execute effectively. Different performance indicators will be provided and examined in order to determine which one is the greatest indicator to choose the best model during the process of determining the best model. Sensitivity, Specificity, Precision, F1 Score, and Geometric Mean are a few of the markers that are listed. Additionally, their trends for the various parameter values of the examined models will be shown and analysed. The strong performance of these machine learning algorithms will once more be supported in this thesis. the affirmation of the significance and practical use of these methodologies, as in the case of this project, to comprehend processes and behaviours. All fields can benefit from the information gleaned, and a successful application will undoubtedly yield financial rewards. The two machine learning applied algorithms' default and best models are finally shown, and their advantages and disadvantages will be evaluated while taking into account the many scenarios that exist. This thesis will demonstrate the good performance of both models, with XGB significantly outperforming RF. It will also demonstrate that while XGB performs better on precision and RF has better results on sensitivit

Extração e aplicação de indicadores no processo de recomendação de recursos urbanos utilizando dados estruturados e não-estruturados

Considerando o estudo do desenvolvimento de sistemas voltados a ambientes urbanos através da Informática Urbana, e tendo que dados referentes a tais de cenário encontramse muitas vezes dispersos, em diferentes formas e estruturas e, em alguns casos, com procedência duvidosa, processos de recuperação e análise de informações tornam-se nãotriviais. Nesse cenário, métodos capazes de extrair informações anteriormente desconhecidas ou não mensuradas e de valor para algum domínio são de fundamental importância. Diante de tal perspectiva, o principal objetivo desta pesquisa consiste em desenvolver uma abordagem capaz de extrair e analisar informações expressas em redes sociais baseadas em localização com o uso de Mineração de Textos, de modo a relacionar aspectos referentes a polaridade de informações e a confiabilidade dos perfis que as difundiram, bem como considerar o momento de avaliação, gerando indicadores a serem aplicados no processo de recomendação de recursos urbanos verificando tal influência ao estimar métricas de avaliação. Para tanto, procede-se a aplicação de uma metodologia baseada em premissas de análise de redes sociais, associada a aplicação de abordagens de Web Mining no processo de descoberta de conhecimentos e análise de dados Como fonte de informações foi utilizado um conjunto de dados contendo 6600 observações coletadas no Foursquare, referentes à cidade de Gramado no Rio Grande do Sul, organizadas em 13 variáveis, além de informações complementares fornecidas pela plataforma DataViva. As características extraídas foram então aplicadas a algoritmos de recomendação baseados em vizinhança e em fatoração de matrizes, de modo a apurar métricas de acurácia com seu uso. Dos resultados obtidos, observa-se que, para algoritmos baseados em vizinhança, a abordagem proposta apresentou resultados melhores quando comparada à abordagem tradicional de avaliação. Entretanto, ao utilizar algoritmos baseados em fatoração de matrizes, as taxas de erro mantém-se com médias e desvios-padrão baixos. Os resultados obtidos foram comparados utilizando testes deWilcoxon com 95% de confiança, o que permite concluir que esses retratam a não uniformidade na distribuição das amostras, evidenciando diferenças significativas entre os resultados obtidos.As a source, a dataset containing 6600 observations was collected at Foursquare, referring to the city of Gramado in Rio Grande do Sul. In this dataset, 13 variables were considered, and complementary information was provided by DataViva platform. The extracted features were applied to recommender approaches based on neighborhood and matrix factorization, and their use was measured in terms of accuracy. From the results, it is observed that the approach based on neighborhood algorithms presented better results when compared to the traditional evaluation approach. However, when using algorithms based on matrix-factorization, error rates are maintained with low standard means and standard deviations. The results obtained with the use of both metrics were compared using Wilcoxon tests with 95% confidence, which concludes that they portray the nonuniformity in the distribution of the samples, evidencing significant differences between the results obtained with the use of the approaches used

Resources Protection: Towards Replacement of Cotton Fiber with Polyester

L'abstract è presente nell'allegato / the abstract is in the attachmen

Design and analysis of a content-based image retrieval system

The automatic retrieval of images according to the similarity of their content is a challenging task with many application fields. In this book the automatic retrieval of images according to human spontaneous perception without further effort or knowledge is considered. A system is therefore designed and analyzed. Methods for the detection and extraction of regions and for the extraction and comparison of color, shape, and texture features are also investigated

Multiphase gas transport in a shear zone

In the post-operational phase of a Low/Intermediate-Low radioactive waste repository, gas will be generated in the caverns due to anaerobic corrosion of metals, and also chemical and microbial degradation of organic substances. Previous investigations on gas migration have indicated that discrete water conducting features (e.g. shear zones) are mainly responsible for gas transport from the caverns through the geosphere. Two phase flow processes occur in these water conducting features; the continuity and spatial distribution of pore spaces, the pore size distribution and the interfacial forces of the three phases gas-water-rock have a significant influence on gas transport.The main difficulties to be resolved when simulating two-phase flow processes in fractured rock are:- The description of the internal heterogeneity of the individual water conducting features. The influence of channelling along preferential flow paths is even more important than for single phase fluid flow, because gas transport takes place more or less exclusively along the most transmissive channels. - The determination of effective mass exchange coefficients of the relevant components of the system. Mass exchange may occur between three phases (gas-water-rock). It depends on the spatial distribution of water and gas along the water conducting features (i.e. specific surface of contact areas between phases), and on the solubility and diffusivity of the different components, but also on a couple of state variables of liquid phase (initial content of dissolve/free gas, initial pressure).The work presented in this thesis aims to improve the understanding of the physics of single and multiphase transport phenomena, to be able to develop a quantitative description of gas transport in shear zones to overcome in a satisfactory way the problems described above.Postprint (published version

Spectral classification & physical parameters of the IPHAS CBe stars in the BCD system.

The INT Photometric Hα Survey (IPHAS) has detected tens of thousands of emission line objects in the Northern Galactic Plane. Spectroscopic follow-up has shown that the vast majority of them are Classical Be (CBe) stars, rapidly rotat- ing main sequence B type stars which develop an outflowing circumstellar disk by mechanisms not yet completely understood. In this work we present a study of the full catalogue of the CBe stars discovered by IPHAS. We have analyzed 805 low resolution spectra of 732 IPHAS CBe stars. With a semi-automatic proce- dure, which we evaluate at the first part of this work, we obtained the relevant physical parameters, including the effective temperature, surface gravity, absolute magnitude and distance, based on the techniques of the Barbier-Chalonge-Divan (BCD) spectrophotometric system. Also, we plot an HR diagram from which we extracted masses and ages. From the data in the catalogue we have determined for the sample a mean rotational velocity of 82% of the critical velocity, without any trend of variation with the spectral type. The data also confirm that the circumstellar discs rotate following a Keplerian velocity law. We found the ages of the stars evenly distributed be- tween the ZAMS and the TAMS, and hence our results do not support claims of an evolutionary nature of the Be phenomenon. The distribution of the stars does not present an apparent clustering in or around the Perseus or the Outer Arm regions. Instead, they appear scattered along the two arms and the space in between, with some stars spreaded along larger dis- tances, beyond the expected location of the Outer Arm. The density of the stars beyond the Perseus Arm displays a similar exponential decline at all longitudes along the Northern Galactic Plane. No evidence of an outer Arm beyond the Perseus Arm is present in our data.The INT Photometric Hα Survey (IPHAS) has detected tens of thousands of emission line objects in the Northern Galactic Plane. Spectroscopic follow-up has shown that the vast majority of them are Classical Be (CBe) stars, rapidly rotat- ing main sequence B type stars which develop an outflowing circumstellar disk by mechanisms not yet completely understood. In this work we present a study of the full catalogue of the CBe stars discovered by IPHAS. We have analyzed 805 low resolution spectra of 732 IPHAS CBe stars. With a semi-automatic proce- dure, which we evaluate at the first part of this work, we obtained the relevant physical parameters, including the effective temperature, surface gravity, absolute magnitude and distance, based on the techniques of the Barbier-Chalonge-Divan (BCD) spectrophotometric system. Also, we plot an HR diagram from which we extracted masses and ages. From the data in the catalogue we have determined for the sample a mean rotational velocity of 82% of the critical velocity, without any trend of variation with the spectral type. The data also confirm that the circumstellar discs rotate following a Keplerian velocity law. We found the ages of the stars evenly distributed be- tween the ZAMS and the TAMS, and hence our results do not support claims of an evolutionary nature of the Be phenomenon. The distribution of the stars does not present an apparent clustering in or around the Perseus or the Outer Arm regions. Instead, they appear scattered along the two arms and the space in between, with some stars spreaded along larger dis- tances, beyond the expected location of the Outer Arm. The density of the stars beyond the Perseus Arm displays a similar exponential decline at all longitudes along the Northern Galactic Plane. No evidence of an outer Arm beyond the Perseus Arm is present in our data