Agri-Environmental Policies When the Spatial Pattern of Biodiversity Reserves Matters

The aim of this paper is to compare different policy instruments for cost-effective habitat conservation on agricultural lands, when the desired spatial pattern of reserves is a random mosaic. We use a spatially explicit mathematical programming model which studies the farmers' behavior as profit maximizers under technical and administrative constraints. Facing different policy measures, each farmer chooses its land-use at the field level, which determines the landscape at the regional level. A spatial pattern index (Ripley L function) is then associated to the obtained landscape, indicating on the degree of dispersion of the reserve. We compare a subsidy per hectare of reserve with an auction scheme and an agglomeration malus. We find that the auction is superior to the uniform subsidy both for cost-efficiency and for the spatial pattern of the reserve. The agglomeration malus does better than the auction for the spatial pattern but is more costly.agri-environmental policies, biodiversity, mathematical programming, spatial optimization, reserve design, cost-efficiency, Environmental Economics and Policy, Resource /Energy Economics and Policy, H23, Q57, Q12, Q28,

The beta-transformation's companion map for Pisot or Salem numbers and their periodic orbits

The -transformation of the unit interval is de ned by T (x) := x (mod 1). Its eventually periodic points are a subset of [0; 1] intersected with the eld extension Q( ). If > 1 is an algebraic integer of degree d > 1, then Q( ) is a Q-vector space isomorphic to Q d , therefore the intersection of [0; 1] with Q( ) is isomorphic to a domain in Q d . The transformation from this domain which is conjugate to the -transformation is called the companion map, given its connection to the companion matrix of 's minimal polynomial. The companion map and the proposed notation provide a natural setting to reformulate a classic result concerning the set of periodic points of the -transformation for Pisot numbers. It also allows to visualize orbits in a d-dimensional space. Finally, we refer connections with arithmetic codings and symbolic representations of hyperbolic toral automorphisms

Gestão de conteúdos digitais em múltiplos monitores

With the generalized use of systems for digital contents dissemination arises the opportunity for implementing solutions capable of evaluating audience reaction. This dissertation reflects the implementation of one of those solutions. To this end, the development involved adapting a previously functional digital signage system. In this sense, digital cameras were paired to the content display terminals in order to capture information from the area in front of them. Using computer vision technologies, the terminals detect, in real time, people who appear in the cameras’ field of view, and this information is communicated to a server for data extraction. On the server, methods are used to perform face and emotion recognition, and also to extract data indicating the position of the head, which allows the calculation of an attention coefficient. The data is stored in a relational database, and can be consulted through a web platform, where they are presented associated with the contents corresponding to the moment of their capture and extraction. This solution thus allows the evaluation of the impact of the digital contents presented by the system.Com a utilização generalizada de sistemas de disseminação de conteúdos digitais, surge a oportunidade de implementar soluções capazes de avaliar a reacção do público. Esta dissertação reflete a implementação de uma dessas soluções. Para isso, o desenvolvimento passou pela adaptação de um sistema de sinalização digital previamente funcional. Neste sentido, aos terminais de exposição de conteúdos, foram emparelhadas câmaras digitais de modo a permitir a captação de informação da área à frente destes. Com recurso a tecnologias de visão de computador, os terminais fazem, em tempo real, deteção de pessoas que apareçam no campo de visão das câmaras, sendo esta informação comunicada a um servidor para extração de dados. No servidor, são utilizados métodos para realização de reconhecimento de faces e emoções, e também é feita extração de dados indicadores da posição da cabeça, o que permite o cálculo de um coeficiente de atenção. Os dados são guardados numa base de dados relacional e podem ser consultados através de uma plataforma web, onde são apresentados associados aos contéudos correspondentes ao momento de captação e extração destes. Esta solução, permite, assim, a avaliação do impacto dos conteúdos digitais apresentados pelo sistema.Mestrado em Engenharia de Computadores e Telemátic

The seasonality structure of demand in the portuguese hotel industry before the COVID-19 pandemic

The purpose of this paper is to study the monthly seasonality structure of demand in the hotel industry in continental Portugal before the outbreak of the COVID-19 pandemic in 2020. The tourism sector accounts for more than 10% of Portugal’s GDP, as well as being a key factor for regional development and employment. Understanding the seasonality structure of the hotel sector provides useful insight about business viability and aids operational decisions, namely concerning the post-pandemic recovery. Therefore, we analyze time-series data collected from Statistics Portugal, concerning net bed occupancy rates for continental Portugal, as well as according to region and hotel category, for the pre-pandemic period between 2014 and 2019. This allows us to identify the seasonal peaks according to region and compare the differences in demand for hotels according to hotel category. We also analyze the relationship between the seasonality coefficients and the average income per night (room rate)

Mind the gap: characterization of periplasmic cytochromes from Shewanella oneidensis involved in extracellular electron transfer

Dissertation presented to obtain the Ph.D degree in BiochemistryDissimilatory iron reduction (DIR) is an important biogeochemical process with a strong impact not only on the iron cycle but also on the biogeochemical cycles of other elements, changing dramatically the composition of the planet’s sediments and soils.(...

A Simple Industrial Process Simulation with Mindstorms NXT as Tool in Automation Lessons

This work presents the development of a simulation prototype for an automated manufacturing process using the Mindstorms NXT LEGO© robotic kit. This process consists of assembling a basic product, namely a mini car done with LEGO© pieces, into two phases. First, the coupling of the body and chassis and after this, the separation of assembled products by colour. The intent here is to show that it is possible to create an automated system with NXT, like a mockup, that can be simulate a real system, and which has similarity to an automated system using a Programmable Logic Controller (PLC), with the advantage of being more practical and cheaper than an educational simulation system with PLC. The aims here is present an adaptable tool, to auxiliar the automation teaching and to motivate to use of new technological tools in classroom

Matemática para economia e gestão

Matemática para Economia e Gestã

Comportamentos de risco associados às modalidades desportivas de pavilhão: um estudo exploratório

Existe um crescente interesse em outras modalidades para além do futebol, nomeadamente as praticadas em pavilhão (ex: futsal, andebol, hóquei em patins, etc.). Estas modalidades destacam-se pela emoção e pela tensão que é criada num ambiente fechado, onde todo o espetáculo desportivo ganha uma outra dimensão. Assim, existe uma maior afluência aos pavilhões, o que, por sua vez, acarreta uma maior complexidade no planeamento da gestão da segurança deste tipo de eventos à Polícia de Segurança Pública. Vários estudos indicam que a atuação da polícia nestes eventos deve ser direcionada de modo a ser percecionada como legítima e a evitar desordens generalizadas. As ameaças ao evento são geradas pelos comportamentos. Posto isto, a polícia não deve agir sobre os adeptos de forma discriminatória apenas pela sua tipologia, devendo a sua ação incidir sobre aqueles que têm comportamentos de risco. De forma a identificar os comportamentos de risco associados a estas modalidades, e com recurso à definição de comportamentos de risco, foi realizado um estudo exploratório. Foi possível não só identificar esses comportamentos como caraterizá-los quanto ao espaço e tempo em que normalmente decorrem. Através dos resultados obtidos, é possível dotar a instituição de conhecimento prático que pode servir a todos os envolvidos neste tipo de eventos de forma a serem desenvolvidas estratégias que minimizem ou previnam, em tempo útil, os comportamentos de risco. Uma boa atuação policial beneficia tanto a polícia como o adepto.There is a growing interest in other modalities besides football, namely those practiced indoor (ex: futsal, handball, roller hockey, etc.). These modalities stand out by the emotion and tension that is created in a closed environment, where the whole sporting spectacle gains another dimension. Thus, there is a greater turnout to the pavilions, which, in turn, entails greater complexity in planning security management of this type of events to the Public Security Police (PSP). Several studies indicate that police actions in these events should be directed in order to be perceived as legitimate and to avoid generalized disorders. The threats to the event are generated by the behaviours. Therefore, the police should not act on supporters in a discriminatory manner only by their typology, and their action should be focused on those who have risky behaviours. In order to identify the risk behaviours associated with these modalities, and with the definition of risk behaviours, an exploratory study was conducted. It was possible not only to identify these behaviours but also to characterize them as to the space and time in which they normally occur. Through the results obtained, it is possible to provide the institution of practical knowledge that can serve all those involved in this type of events in order to develop strategies that minimize or prevent risky behaviours in a timely manner. A good police performance benefits both the police and the adept