SDR for Physical Layer Authentication

Wireless networks and devices are easy and useful solutions nowadays, regardless of the context in which they are implemented. However, it is in the broadcast nature of wireless networks that some vulnerabilities arise. To protect against these vulnerabilities, encryp- tion and authentication methods are commonly used. However, such methods come at the expense of their own complexity, requiring high enough computational power to solve, and introducing latency. To try to reduce the complexity of the conventional ways of user authentication, this work has studied mechanisms to implement reliable authentication at the physical layer, analyzing the various devices signal characteristics. To achieve this analysis, the GNU Radio platform was used to process incoming signals and extract the necessary features. Given the open source nature of GNU Radio, this provides a customiz- able and low-cost solution to signal processing and feature extraction. This research uses the GNU Radio to implement a feature extraction solution and constructs a feature vector with size 1 × 95. This thesis studies the extracted features of eleven IEEE 802.15.4 devices in regards to their separability and proposes a solution for feature reduction. The feature vectors are passed through a Random Forest and a Deep Neural Network (DNN) classifier, achieving accuracies as high as 99% for short distance communication.Redes e dispositivos sem fio são implementações úteis e fáceis de realizar atualmente, independentemente do contexto em que são desenvolvidas. No entanto, é na natureza de difusão destas redes que surgem algumas vulnerabilidades. Métodos de criptografia e autenticação são usualmente utilizados para proteger contra essas vulnerabilidades. No entanto, esses métodos apresentam uma complexidade inerente, necessitando de poder computacional e introduzindo latência. Para tentar reduzir a complexidade das formas convencionais de autenticação de utilizadores das redes, esta dissertação estudou me- canismos para implementar uma autenticação fiável na camada física, analisando as ca- racterísticas dos sinais dos diversos dispositivos que utilizam a rede. Para realizar esta análise, a plataforma GNU Radio foi utilizada para processar sinais recebidos e extrair as características necessárias. Dada a natureza de código aberto do GNU Radio, é possível desenvolver uma solução customizável e de baixo custo. Esta dissertação utiliza o GNU Radio para implementar uma solução de extração de características e constrói um vetor de características de tamanho 1×95. Esta dissertação estuda as características extraídas de onze dispositivos IEEE 802.15.4 em relação à separabilidade destas e propõe uma solução para redução de características. Os vetores são passados por um classificador de Florestas Aleatórias (Random Forest) e um classificador de Redes Neurais Profundas, atingindo precisões de até 99% para comunicação a curta distância

The economic value of Portuguese pine and eucalyptus forests

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and EconomicsThis paper estimates the total economic value for the Portuguese pine and eucalyptus forest ecosystems considering market services (timber and non timber forest products) and non-market services (recreation, landscape, carbon sequestration, watershed protection, protection of soil erosion and biodiversity). According to the results obtained, at least half of the values of the ecosystems in study come from non-market services, and eucalyptus forests are more valuable than pine forests, even after including fire risks. Moreover, the results also suggest a non-optimal management of Portuguese pine forests

Development of a Digital Repository Prototype applied to Faculty of Pharmacy, University of Lisbon

University libraries have played a key role in scientific research as well as in the support of education-related activities. Their main goal is to provide their users with immediate access to relevant information through updated information sources. Science evolves rapidly and so the daily information needs on health matters are large and require rapid access to the sources. One of the problems that currently exist in university libraries is the access and processing of information in digital format. Digital objects are technologically diverse and there is not enough technical information regarding its proper handling. In this paper we present the tools and methodologies that should be used to provide, in an organized and validated way, the wide range of existing information in a digital format. This work was done in the context of a Master of Science thesis in Information Studies and Digital Libraries. The aim was to find practical solutions for the processing and offering of information in digital format in the context of pharmaceutical sciences. Finally, the paper presents reliable benchmarking of best practices to implement and evaluate a prototype applied to the Pharmaceutical Sciences, in order to satisfy the user’s needs

An integrated system for tourism destination management: reflections and proposal of a conceptual model from the perspective of hospitality

This report presents the experience of the implementation of the “Tourism Observatory | SIGESTur” project, an action developed at the Federal Institute of São Paulo (IFSP Campus Cubatão). The project began in 2016, as result of academic research and university extension activity. This work reports and analyzes the results of the project, and proposes a model for innovative management of tourism destinations in the Brazilian context. In its first year, the project was considered one of the ten most innovative ideas in Brazilian tourism, at the I Tourism Innovation Camp, a contest promoted by the Panrotas portal with technical support from Sebrae (national development agency). In 2017, the case entitled “Hospitality and hostility relations among stakeholders: Influences in the competitiveness of tourist destinations” received an award during the IV World Research Summit for Tourism and Hospitality, a congress held in Orlando (USA). The project consists of two work fronts. For the elaboration of this report of experience, bibliographical and documentary research were carried out. The data analysis was done in 2019 to ensure that all previous actions were recorded. In the results, the establishment of a model is highlighted, for collecting, processing and analyzing data and distributing information to professionals in the travel and tourism industry

U.dream goes to market - an evaluation of crescer com consciência and analysis of the internal and external environments affecting its strategic pPosition

U.Dream is a social enterprise targeted at developing social leadership skills. It recently launched U.Purpose (service) and Crescer com Consciência (product) aiming to ensure future financial sustainability. However, these were launched without conducting a market research and clear guiding strategy. The focus of this project is to assess the attractiveness of the CSR and children’s book markets and U.Dream’s current strategy, providing a strategic revision. An in-depth analysis concluded that, in order to face the stagnant book market conditions and the fierce competition, the way for the Crescer com Consciência initiative to prosper is through differentiation and effective communicatio

The impact of journal editors in academic publications: A stochastic frontier analysis

Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Knowledge Management and Business IntelligenceSince the task of deciding whether a research work is published or not is carried out by journal editors, the composition and attributes of editorial board members are relevant variables to be investigated. In particular, when trying to understand if the scientific knowledge shared with the world is impacted by other factors instead of being judged solely by the quality and content of the research. Hence, this research analyses the composition of editorial teams from 27 journals in three main areas – Economics & Econometrics, Finance, and Business & International Management - and their influence on the efficiency of such journals. After collecting the data required to perform this study, the composition and characteristics of editorial board members, as well as an analysis aiming to identify patterns between editors’ characteristics and the context and impact of scientific publication journals were carried out. Some of the data collected about the editors and journals for the analyses were the gender, geography, affiliated institution, publisher’s categories, position in those categories, H-index, and SCImago Journal Rank. The gathered data was then used to build a Stochastic Frontier Analysis (SFA) model to analyze journals’ efficiency, as input. The SFA allows us to develop a multi-input single-output scenario. Primary findings suggest that the performance of research journals’ is influenced by the size of the editorial board, gender, and location but not by the performance of each editor as an individual. There is an overwhelming presence of US-based, male, and academic editors among the editorial boards as well as US institutions represented by scholars. The results show that economics and finance journals tend to be more efficient than business journals and that the research industry, despite having a small margin to improve, appears to be efficient

Thermal vorticity production in relativistic dissipative fluids

We have computed the circulation integrations of thermal vorticity with and without charged currents in dissipative fluids. We find that the relativistic Kelvin circulation theorem will be modified by the dissipative effects, therefore, the circulation integrations of thermal vorticity may not be conserved during the fluid evolution.Comment: Presented by S. Pu at Critical Point and Onset of Deconfinement (CPOD), Wroclaw, Poland, May 30 - June 4, 201

Diagnosing Insensitivity to Scope in Contingent Valuation

Sensitivity to scope is considered a desirable property of contingent valuation studies and often treated as a necessary condition for validity. We first provide an overview of scope insensitivity explanations put forth in the environmental valuation literature. Then we analyze data from a contingent valuation survey eliciting willingness-to-pay to prevent oil spills of four different magnitudes in Arctic Norway. In the baseline analysis, the scope inference is ambiguous. There is only statistical difference in willingness to pay to avoid a very large versus small oil spill (NOK 1869 and NOK 1086, respectively). However, further explorations show that several confounding factors suggested in the literature influence the scope inference. The scope sensitivity improves when we control for subjective probabilities of amenity provision, exclude respondents based on the debriefing questions, take into consideration the sample sizes, and impose diminishing marginal utility. Overall, the analysis supports an emerging view in the contingent valuation literature suggesting that statistical scope insensitivity is not a sufficient reason for deeming a study invalid.publishedVersio

On the Validity and Reliability of coastal quality change estimates: Evidence from Norway

Coastal managers are faced with the challenge of managing sites to maintain or improve their quality. The quality of each coastal site is characterized by site attributes that visitors care about. Since coastal managers face financial constraints, it is useful to know which are the site attributes with the highest implicit value for visitors and thus determine the change in attributes that yields the most benefits. However, estimates of implicit value of site attributes should be both valid and reliable to be informative for coastal managers. If coastal sites present similar characteristics, the data can suffer from lack of variation that can lead to unreliable estimated implicit values. We first present our strategy relying on simulation that confirms that our estimates are unbiased, but only a subset of these is reliable. We then apply the discrete choice model to explain recreational beach site choice by using two alternative models with a view to increase precision of our estimates. We uncover preference heterogeneity by relying on observable group characteristics. We illustrate the policy-relevance of our approach by providing welfare estimates for three scenarios currently being considered by Norwegian beach managers.This research was funded by the Norwegian Research Council in the context of the COAST-BENEFIT project (project number 255777). The second author acknowledges financial support from FEDER/Spanish Ministry of Economy and Competitiveness through grant ECO2017-82111-R and the Basque Government through grant IT1359-19