TBM pressure models: calculation tools

Mechanized tunnel construction in soft ground has evolved significantly over the last 20 years, especially on the matter of settlement control. This was achieved by guiding the TBM operation to control the main factors that induce soil displacements, namely the face pressure and the closure of the soil-lining void. Nowadays, TBMs can be operated within strict serviceability requirements. However, several mechanisms of the excavation cycle are still not taken into account when estimating the induced soil deformations. Therefore, it is important to properly model the processes around a TBM, but in order for such models to be assimilated in the state of practice, they should be combined in a design framework where the operational characteristics can be assessed together with the induced soil displacements and lining forces for different project conditions. This paper presents the first step of this general project by focusing on the tail void grouting pressures. A model for the grout flow is associated with a finite element model to calculate the induced soil displacements in a dynamic equilibrium between the boundary pressures and the soil-lining gap. These two elements are combined in a calculation tool with a user friendly input-output layout

Pile tunnel interaction: literature review and data analysis

The underground space of densely populated cities contains deep foundations and tunnels. Considering the possibility that a new tunnel can be built close to existing piles it is necessary to assess the possible effects of that interaction. Most case studies have shown limited damage on pile supported structures; however, these constructions deal with great uncertainty as the mechanism of pile tunnel interaction is not completely understood. Physical tests at full and reduced scale are a valuable tool to improve that understanding and validate prediction methods. A descriptive review of studies on that matter is presented followed by a quantitative comparison of the results of tunnelling induced axial forces and settlements on the piles. Gathering and analysing these data provided a deeper understanding of the influencing geometrical and structural parameters as well as indicating where further research is needed

TBM pressure models: observations, theory and practice

Mechanized tunnelling in soft ground has evolved significantly over the last 20 years. However, the interaction between the tunnel boring machine (TBM) and the ground is often understood through idealized concepts, focused mostly on the machine actions in detriment of the reactions from the ground. These concepts cannot be used to explain several mechanisms that have been observed during the construction of mechanized tunnels. Therefore, this paper presents the path from field observations to the theoretical developments to model the TBM-ground interaction more realistically. Some ideas on how these developments can be applied into practice are presented. Finally, a discussion is proposed about how an effective collaboration between academia and industry can alleviate the current concentration of knowledge in the state of practice

3D Reconstruction with Low Resolution, Small Baseline and High Radial Distortion Stereo Images

In this paper we analyze and compare approaches for 3D reconstruction from low-resolution (250x250), high radial distortion stereo images, which are acquired with small baseline (approximately 1mm). These images are acquired with the system NanEye Stereo manufactured by CMOSIS/AWAIBA. These stereo cameras have also small apertures, which means that high levels of illumination are required. The goal was to develop an approach yielding accurate reconstructions, with a low computational cost, i.e., avoiding non-linear numerical optimization algorithms. In particular we focused on the analysis and comparison of radial distortion models. To perform the analysis and comparison, we defined a baseline method based on available software and methods, such as the Bouguet toolbox [2] or the Computer Vision Toolbox from Matlab. The approaches tested were based on the use of the polynomial model of radial distortion, and on the application of the division model. The issue of the center of distortion was also addressed within the framework of the application of the division model. We concluded that the division model with a single radial distortion parameter has limitations

Design and construction aspects of a geocomposite drainage system in a dam

The drainage system of a dam depends mainly of the available granular material founded near the dam site and it’s quantities. In some cases, the use of natural granular materials can reach an impracticable cost considering the transportation and the required quality of the material. Geosynthetic materials and, in particular, drainage geocomposites offers constructive alternatives to traditional solutions on internal drainage systems. This paper discusses the design and construction of a geosynthetics system, and presents a case in which a traditional granular material drainage system was successfully replaced by a geocomposite drainage syste

Can machine learning algorithms predict football players´ market values? A data-driven approach

Football players transfer fees have been increasing in an unprecedented manner in the last decade. As so, it is crucial for football clubs to correctly assess the value of its players. To tackle this problem, this thesis proposes a data-driven solution. After assembling a dataset with data regarding football players’ characteristics, on-field performance indicators and market values, Machine Learning algorithms were used to construct a prediction model. The final proposed modelis a Random Forest regression, whichregistered a coefficient of determination (R2)of 0.88in the test set, displaying a promising outcome for future research

FuzzTheREST - Intelligent Automated Blackbox RESTful API Fuzzer

In recent years, the pervasive influence of technology has deeply intertwined with human life, impacting diverse fields. This relationship has evolved into a dependency, with software systems playing a pivotal role, necessitating a high level of trust. Today, a substantial portion of software is accessed through Application Programming Interfaces, particularly web APIs, which predominantly adhere to the Representational State Transfer architecture. However, this architectural choice introduces a wide range of potential vulnerabilities, which are available and accessible at a network level. The significance of Software testing becomes evident when considering the widespread use of software in various daily tasks that impact personal safety and security, making the identification and assessment of faulty software of paramount importance. In this thesis, FuzzTheREST, a black-box RESTful API fuzzy testing framework, is introduced with the primary aim of addressing the challenges associated with understanding the context of each system under test and conducting comprehensive automated testing using diverse inputs. Operating from a black-box perspective, this fuzzer leverages Reinforcement Learning to efficiently uncover vulnerabilities in RESTful APIs by optimizing input values and combinations, relying on mutation methods for input exploration. The system's value is further enhanced through the provision of a thoroughly documented vulnerability discovery process for the user. This proposal stands out for its emphasis on explainability and the application of RL to learn the context of each API, thus eliminating the necessity for source code knowledge and expediting the testing process. The developed solution adheres rigorously to software engineering best practices and incorporates a novel Reinforcement Learning algorithm, comprising a customized environment for API Fuzzy Testing and a Multi-table Q-Learning Agent. The quality and applicability of the tool developed are also assessed, relying on the results achieved on two case studies, involving the Petstore API and an Emotion Detection module which was part of the CyberFactory#1 European research project. The results demonstrate the tool's effectiveness in discovering vulnerabilities, having found 7 different vulnerabilities and the agents' ability to learn different API contexts relying on API responses while maintaining reasonable code coverage levels.Ultimamente, a influência da tecnologia espalhou-se pela vida humana de uma forma abrangente, afetando uma grande diversidade dos seus aspetos. Com a evolução tecnológica esta acabou por se tornar uma dependência. Os sistemas de software começam assim a desempenhar um papel crucial, o que em contrapartida obriga a um elevado grau de confiança. Atualmente, uma parte substancial do software é implementada em formato de Web APIs, que na sua maioria seguem a arquitetura de transferência de estado representacional. No entanto, esta introduz uma série vulnerabilidade. A importância dos testes de software torna-se evidente quando consideramos o amplo uso de software em várias tarefas diárias que afetam a segurança, elevando ainda mais a importância da identificação e mitigação de falhas de software. Nesta tese é apresentado o FuzzTheREST, uma framework de teste fuzzy de APIs RESTful num modelo caixa preta, com o objetivo principal de abordar os desafios relacionados com a compreensão do contexto de cada sistema sob teste e a realização de testes automatizados usando uma variedade de possíveis valores. Este fuzzer utiliza aprendizagem por reforço de forma a compreender o contexto da API que está sob teste de forma a guiar a geração de valores de teste, recorrendo a métodos de mutação, para descobrir vulnerabilidades nas mesmas. Todo o processo desempenhado pelo sistema é devidamente documentado para que o utilizador possa tomar ações mediante os resultados obtidos. Esta explicabilidade e aplicação de inteligência artificial para aprender o contexto de cada API, eliminando a necessidade de analisar código fonte e acelerando o processo de testagem, enaltece e distingue a solução proposta de outras. A solução desenvolvida adere estritamente às melhores práticas de engenharia de software e inclui um novo algoritmo de aprendizagem por reforço, que compreende um ambiente personalizado para testagem Fuzzy de APIs e um Agente de QLearning com múltiplas Q-tables. A qualidade e aplicabilidade da ferramenta desenvolvida também são avaliadas com base nos resultados obtidos em dois casos de estudo, que envolvem a conhecida API Petstore e um módulo de Deteção de Emoções que fez parte do projeto de investigação europeu CyberFactory#1. Os resultados demonstram a eficácia da ferramenta na descoberta de vulnerabilidades, tendo identificado 7 vulnerabilidades distintas, e a capacidade dos agentes em aprender diferentes contextos de API com base nas respostas da mesma, mantendo níveis de cobertura aceitáveis

Dalkurd FF: being an Uppsala club during a pandemic

Enquanto o mundo inteiro lida com o surgimento de uma pandemia, indivíduos e instituições começam a lidar com a perspectiva de mudanças tanto de curto quanto longo prazo para os seus planos. O que fora planejado por muitos durante janeiro e fevereiro de 2020, não mais seria possível durante os meses subsequentes. Logo, com a impossibilidade de se saber por quanto tempo a situação persistiria, ambos indivíduos e instituições mudariam seus planos, focando em quando a situação se reverteria para um grau de normalidade. Esse artigo busca brevemente entender e analisar as estratégias centradas em torno de um clube de futebol sueco fundado por indivíduos curdos em relação as consequências da crise do coronavírus no país. Ambos torcedores e funcionários do clube mudariam suas estratégias em relação ao primeiro ano que estaria atuando na sua nova cidade-sede de Uppsala. Argumenta-se que, apesar da crise ter mudado a estratégias e dificultado os seus planos de se tornarem uma instituição local, ela, de fato, não teria mudado seus planos de serem uma parte integrada da cidade, mas sim, teria provido ao clube com novas oportunidades de fazê-lo.Como todo el mundo lucha contra la emergencia de una pandemia en larga escala, individuos, instituciones empiezan a tratar de la perspectiva de cambios de planes de medio y largo plazo. Lo que se había planeado para muchos el febrero de 2020 ya no sería posible en los meses siguientes. Así que, con la imposibilidad de saber por cuánto tiempo esa situación va a persistir tanto los individuos como las instituciones han cambiado sus planes con un enfoque en cuando la situación se va a revertir para un grado de normalidad. Ese artículo intenta comprender y analizar brevemente las estrategias que se han centrado en clube de fútbol de Kurdos en Suecia respecto a las consecuencias de la crisis del coronavirus en el país. Tanto los aficionados como los empleados del clube han cambiado sus estrategias respeto al primer año que irían a jugar en su nuevo hogar, la de ciudad de Uppsala. Se argumenta que la crisis ha cambiado la estrategia y dificultaron sus planes de convertirse en una institución local, pero eso, de hecho, no ha cambiado sus planes de integrarse a la ciudad. Sin embargo, esa situación ha otorgado al clube una nueva oportunidad de integrarsAs the whole world struggles with the appearance of a large-scale pandemic, individuals and institutions begin to cope with the perspective of both short and long-term changes to their plans. What had been planned out by many during January and February of 2020, no longer became feasible already during the following months. Thus, with the impossibility of knowing for how long this situation will persist, both individuals and institutions have changed their plans with a focus on when the situation will reverse to a degree of normalcy. This article aims to briefly understand and analyses the strategies centered around a Swedish football club founded by Kurdish individuals regarded to the consequences of the coronavirus crisis in the country. Both fans and employees at the club have changed their strategies regarding the first year they would be playing in their new hometown of Uppsala. The author will argue that, although, the crisis has changed their strategy and hampered their plans of becoming a local institution, it has not, in fact, changed their plans to be an integrated part of the city, but it has provided the club with newer opportunities to do so