Dynamic network modelling and simulation for air traffic flow analysis

This dissertation describes the achievement of a set of equations in order to represent a discrete model for air traffic dynamics in terminal areas. Such a mathematical model could be used to investigate the occupation of a TMA‡ at a single instant and has the potential to be used on the prediction of a future occupation. There are safety and legal limits to how many aircraft should be inside a TMA at once. It could also be useful for an Air Traffic Controller to predict a future overoccupation and thus being able to prevent it. That is why there is an interest to know at each instant an estimate of how many aircraft are in a specific TMA. The idea behind it was to make a Control Theory approach so that the same classical tools used in other topics such as flight dynamics could be applied to this subject. In order for that to happen there were needed some Network notions along with navigation formulae. If an aircraft leaves one place we know a priori that he will follow a path and later enter a certain TMA, unless something goes wrong. That information is known even before lift off. It limits our monitoring window and we can now focus on the physical existence of an aircraft in or out a determined TMA. Every aircraft within a radius of several nautical miles, depending on each TMA, does belong to that TMA. A transition between areas is considered a control input. Knowing the initial amount of aircraft on the zero instant at a particular site we can calculate the following instant state by adding the arrivals and subtracting the departures. This system has mass conservation in a sense that aircraft don’t just disappear - instead they move around and the total number of aircraft on the system remains the same. Depending on the complexity of the system other separated states can be monitored and we could separate the grounded aircraft from the airborne aircraft; allow mid-flight decision change to go to a different TMA, etc. Data retrieved from the website www.localizatodo.com together with Octave Software allowed the validation of the model. On this website the captured transponder signals are transformed into several bits of information from which were retrieved the ones useful: Longitude, Latitude and time stamp. The equations performed as they should, making them applicable to a real scenario, since the utilized data are in fact coming themselves from a real scenario and they are not invented. The first two models are slightly different from the third. One concerns the TMA as if they were contiguous and another considers the paths among each other. They are steps towards an objective, rather than a final solution. The inclusion of a sigmoid function to the model was the latest work to be done. It has to do with the prediction and how much would an incoming airship weight on the eyes of the Air Traffic Controller. There is a need to remove abrupt changes inherent to the model in a way that an aircraft would gradually become present on the arriving TMA from the moment he lifted off the departing TMA, instead of just showing up on the arriving TMA and thus giving no anticipation opportunity to the air traffic controllers. In a future work an estimator, such as a Kalman Filter, should be added to this model or even an improved similar model, since it has the flexibility to incorporate new features in a simple way. There is an explanation on how to perform these additions. This work could be used as a foundation for the implementation of a warning to the Air Traffic Controllers of the occupation status. Not only that but it could be a module on a fully automatic Airspace Controller or even other applications yet to be considered. It could even be applied on the traffic of buses (coaches) and it can be extrapolated to many other fields.Esta dissertação descreve o processo pelo qual se encontraram um conjunto de equações representativas de um modelo discreto de dinâmica de tráfego aéreo em zonas terminais. Tal modelo matemático poderá ser utilizado para investigar a ocupação de uma TMA† num instante singular, tendo o potencial de ser utilizado para prever a ocupação futura. Existem limites de segurança e legais acerca de quantas aeronaves deverão estar dentro de uma TMA de uma só vez. Poderia também ser usável por um Controlador de Tráfego Aéreo em prever uma futura sobre-ocupação e portanto ser capaz de a prevenir. É por isso que existe um interesse em saber a cada instante uma estimativa de quantas aeronaves estão numa TMA específica. A idéia por detrás deste assunto foi a de fazer uma abordagem de Teoria de Controlo de forma a que as ferramentas clássicas utilizadas noutros tópicos, tais como dinâmica de voo, pudessem ser aplicadas a este problema. Para que isso fosse possível eram necessárias noções de Network a par de fórmulas de navegação. Se uma aeronave deixa um determinado sítio sabemos a priori que vai seguir um caminho e mais tarde vai entrar numa TMA específica, a menos que algo corra mal. Essa informação é sabida antes sequer de haver descolagem. Isto permite-nos limitar a nossa janela de monitorização e podemos agora focar-nos na existência física de uma aeronave dentro ou fora de uma determinada TMA. Qualquer aeronave num raio de várias milhas náuticas, dependendo de cada TMA, pertence a essa TMA. Uma transição entre áreas é considerado um input de controlo. Sabendo a quantidade inicial de aeronaves no instante inicial num determinado sítio, podemos calcular o instante seguinte adicionando as chegadas e eliminando as partidas. Este sistema tem conservação de massa no sentido em que as aeronaves não desaparecem. Ao invés elas movem-se de um lado para o outro e o número total de aeronaves num sistema continua o mesmo. Dependendo da complexidade do sistema, outros estados separados poderão ser monitorizados e podemos separar as aeronaves no chão das do ar; permitir alteração de decisão a meio de um voo para dirigir-se a uma TMA diferente, etc. Dados obtidos do sítio web www.localizatodo.com em conjunto com o Software Octave, permitiram a validação do modelo. Neste sítio web os sinais de transponder capturados são depois transformados em vários bits de informação dos quais se retiram os úteis: Longitude, Latitude e carimbo de tempo. As equações comportaram-se como deviam, fazendo este modelo aplicável a um cenário real, já que os dados utilizados de facto provêm eles mesmos de de um cenário real e não de um inventado. Os primeiros dois modelos são ligeiramente diferentes do terceiro. Um deles é relativo às TMA como se elas fossem contíguas umas das outras e segundo já considera os caminhos entre elas. São passos no caminho de um objectivo, em vez de serem uma solução final. A inclusão de uma função sigmóide ao modelo foi o último trabalho a ser efectuado. Tem que ver com a previsão e de quanto pesaria uma aeronave a chegar aos olhos do Controlador de Tráfego Aéreo. Existe uma necessidade de remover mudanças abruptas inerentes ao modelo, de forma que uma aeronave fosse ficando presente gradualmente na TMA de chegada a partir do momento que tenha descolado da TMA de partida, ao invés de somente aparecer na TMA de chegada e assim sendo não dar oportunidade de antecipação aos Controladores de Tráfego Aéreo. Num trabalho futuro um estimador, tal como um Filtro de Kalman, deveria ser adicionado a este modelo ou até a um modelo similar melhorado, já que este tem a flexibilidade de incorporar novas características de uma forma expedita. Existe uma explicação em como fazer essa adições. Este trabalho poderia ser utilizado como fundação para a implementação de um sistema de alerta aos Controladores de Tráfego Aéreo do estado de ocupação. Não só isso como também poderia ser um módulo num Controlador Automático de Espaço Aéreo e mesmo noutras aplicações ainda por considerar. Poderia até ser aplicado no tráfego de autocarros ou poderia ser extrapolado para muitos outros campos

Queue Management in a Government Agency: the case of IRN

Public agencies are, in some cases, the sole providers of essential services to citizens and often suffer from long queues and criticality. Since queues result from higher demand than the available service capacity, Queue Management starts with Capacity and Demand Management. Queue Theory and Queue Psychology contribute to a better waiting experience, aiming at the comfort of those waiting and the regular operation of the service. This internship report analyzes the queue management of a Portuguese government agency. The internship occurred at the "Instituto dos Registos e do Notariado, I.P." (IRN), a Portuguese Ministry of Justice government agency. The research for this report took place at the IRN headquarters and the Civil Identification Department of the Campus of Justice. Case-study research was conducted with semi-structured Interviews as the primary source of evidence, complemented by direct observations, direct participation, and documentation. The conducted root-cause analysis identified the lack of workforce, the citizens' aging process, the CC's sensitive information, and the accumulation of services during the pandemic restrictions as the root causes for the queues at the registry offices. Also, communication difficulties, long waiting hours, lack of waiting conditions, and high human workload were found. IRN's strategies to deal with queues were to reinforce service capacity during peak demand, offer alternative digital services, optimize services, and improve queue organization in the registry offices. The data suggest that SSTs can improve queues; as such, a set of suggestions for implementing SST in registry offices is presented.Os organismos públicos são, em alguns casos, os únicos prestadores de serviços essenciais para os cidadãos, e muitas vezes sofrem com longas filas de espera e criticismo. Uma vez que as filas são o resultado da procura ser mais elevada que a capacidade de serviço disponível, a Gestão das Filas começa com a Gestão da Capacidade e da Procura. A Teoria e Psicologia das Filas de Espera contribuem para uma melhor experiência de espera, visando o conforto de quem aguarda e o normal funcionamento do serviço. Este relatório de estágio analisa a gestão de filas de espera de uma agência governamental portuguesa. O estágio ocorreu no "Instituto dos Registos e do Notariado, I.P.". (IRN), uma agência governamental do Ministério da Justiça Português. A investigação deste relatório realizou-se na sede do IRN e no Departamento de Identificação Civil do Campus da Justiça. A investigação deste estudo de caso utilizou entrevistas semiestruturadas como fonte primária de informação, complementada por observações diretas, participação direta, e documentação. A análise das causas fundamentais identificou a falta de funcionários, o processo de envelhecimento dos cidadãos, a informação confidencial do CC, e a acumulação de serviços durante as restrições pandémicas como as causas fundamentais para as filas de espera nas conservatórias durante o período de estágio. Foram também encontradas dificuldades de comunicação, longas filas de espera, falta de condições de espera, e elevada sobrecarga de trabalho. As estratégias do IRN para lidar com as filas de espera foram o reforço da capacidade de serviço durante o pico da procura, a oferta de serviços digitais alternativos, a otimização dos serviços e melhorias na organização das filas nas conservatórias. Os dados sugerem que as Tecnologias de Self-service (SST) podem melhorar as filas de espera, como tal, é apresentado um conjunto de sugestões para a implementação de SSTs nas conservatórias

Critical success factors when exporting "vinho verde"

The wine industry has played a major role in Portugal’s economy for some time, much of it due to wine exports. These are critical for firms and a path to be pursued in the process of internationalization, as it is proven to bring greater profitability and success, in this highly competitive sector. However, entering foreign markets can bring many challenges to a firm, and those should be evaluated and measured, in order to understand how to overcome them. The solution to these obstacles is the main focus of this research, where the critical success factors for wine exporting are assessed, by understanding what the wine consumers’ preferences are when it comes to the purchase decision-making process. This was done for wine in general, Portuguese wine and Vinho Verde, in order to establish a comparison between them, and to conclude what are the success factors for the export of Vinho Verde. Results show that improving the promotion of the region of Vinho Verde and the overall quality of the wines may be the key to higher export success in the wine industry.A indústria do vinho tem tido um papel importante na economia de Portugal nos últimos anos, e em muito se deve à exportação, que é crucial para as empresas no processo de internacionalização e um caminho a ser seguido, já que está provado trazer grande lucro e sucesso, neste sector extremamente competitivo. Contudo, entrar em mercados estrangeiros pode trazer grandes dificuldades a uma empresa, que devem ser avaliadas e medidas, de forma a compreender como as ultrapassar. A solução para esses obstáculos é o principal foco desta pesquisa, onde os fatores críticos de sucesso para a exportação de vinho são avaliados, ao perceber quais são as preferências do consumidor de vinho no que toca ao processo de decisão de compra. Isto foi feito tanto para o vinho em geral, como para o vinho Português e o Vinho Verde, de maneira a estabelecer uma comparação entre eles, e concluir quais são os fatores de sucesso para a exportação de Vinho Verde. Os resultados evidenciam que a maior promoção da região do Vinho Verde e o melhoramento da qualidade dos vinhos pode ser essencial para obter maior sucesso na exportação na indústria do vinho

Enhancing the efficiency of electricity utilization through home energy management systems within the smart grid framework

The concept behind smart grids is the aggregation of “intelligence” into the grid, whether through communication systems technologies that allow broadcast/data reception in real-time, or through monitoring and systems control in an autonomous way. With respect to the technological advancements, in recent years there has been a significant increment in devices and new strategies for the implementation of smart buildings/homes, due to the growing awareness of society in relation to environmental concerns and higher energy costs, so that energy efficiency improvements can provide real gains within modern society. In this perspective, the end-users are seen as active players with the ability to manage their energy resources, for example, microproduction units, domestic loads, electric vehicles and their participation in demand response events. This thesis is focused on identifying application areas where such technologies could bring benefits for their applicability, such as the case of wireless networks, considering the positive and negative points of each protocol available in the market. Moreover, this thesis provides an evaluation of dynamic prices of electricity and peak power, using as an example a system with electric vehicles and energy storage, supported by mixed-integer linear programming, within residential energy management. This thesis will also develop a power measuring prototype designed to process and determine the main electrical measurements and quantify the electrical load connected to a low voltage alternating current system. Finally, two cases studies are proposed regarding the application of model predictive control and thermal regulation for domestic applications with cooling requirements, allowing to minimize energy consumption, considering the restrictions of demand, load and acclimatization in the system

A data mining approach to predict probabilities of football matches

Com um crescimento cada vez maior dos volumes apostados em competições desportivas torna-se importante verificar até onde as técnicas de aprendizagem computacional conseguem trazer valor a esta área. É feita uma avaliação da performance de algoritmos estado-da-arte em diversas métricas, incorporado na metodologia CRISP-DM que é percorrida desde a aquisição de dados via web-scraping, passando pela geração e seleção de features. É também explorado o universo de técnicas de ensemble numa tentativa de melhorar os modelos do ponto de vista do bias-variance trade-off, com especial foco nos ensembles de redes neuronais.With the increasing growth of the amount of money invested in sports betting markets it is important to verify how far the machine learning techniques can bring value to this area. A performance evaluation of the state-of-art algorithms is performed and evaluated according to several metrics, incorporated in the CRISP-DM methodology that goes from web-scraping through to generation and selection of features. It is also explored the universe of ensemble techniques in an attempt to improve the models from the point of view of bias-variance trade-off, with a special focus on neural network ensembles

Data Fusion in Internet of Things

This dissertation reviews Internet of Things concepts and implementations, state-of-the-art technology with practical examples, as well as data fusion methods applied in different problems. The purpose of this study is to review different data fusion methods and develop a system to provide recognition of human activity that can be applied in day care homes and in hospitals to monitor patients. The system’s objective is to study human activity recognition based on the data recovered by sensors like accelerometers and gyroscopes. In order to transform this data to useful information and practical results to monitoring patients with accuracy and high performance, two different neural networks were implemented. To conclude, the results from the two different neural networks are compared to each other and compared with systems from other authors. It is hoped this study will inform other authors and developers about the performance of neural networks when managing human activity recognition systems

Planning and verification of multipath routing protocols

Conventionally the problem of the best path in a network refers to the shortest path problem. However, for the vast majority of networks present nowadays this solution has some limitations which directly affect their proper functioning, as well as an inefficient use of their potentialities. Problems at the level of large networks where graphs of high complexity are commonly present as well as the appearing of new services and their respective requirements, are intrinsically related to the inability of this solution. In order to overcome the needs present in these networks, a new approach to the problem of the best path must be explored. One solution that has aroused more interest in the scientific community considers the use of multiple paths between two network nodes, where they can all now be considered as the best path between those nodes. Therefore, the routing will be discontinued only by minimizing one metric, where only one path between nodes is chosen, and shall be made by the selection of one of many paths, thereby allowing the use of a greater diversity of the present paths (obviously, if the network consents). The establishment of multi-path routing in a given network has several advantages for its operation. Its use may well improve the distribution of network traffic, improve recovery time to failure, or it can still offer a greater control of the network by its administrator. These factors still have greater relevance when networks have large dimensions, as well as when their constitution is of high complexity, such as the Internet, where multiple networks managed by different entities are interconnected. A large part of the growing need to use multipath protocols is associated to the routing made based on policies. Therefore, paths with different characteristics can be considered with equal level of preference, and thus be part of the solution for the best way problem. To perform multi-path routing using protocols based only on the destination address has some limitations but it is possible. Concepts of graph theory of algebraic structures can be used to describe how the routes are calculated and classified, enabling to model the routing problem. This thesis studies and analyzes multi-path routing protocols from the known literature and derives a new algebraic condition which allows the correct operation of these protocols without any network restriction. It also develops a range of software tools that allows the planning and the respective verification/validation of new protocols models according to the study made