Characterizing and Enforcing Consistency of Online Services

While several proposals for the specification and implementation of various consistency models exist, little is known about what is the consistency currently offered by online services with millions of users. Such knowledge is important, not only because it allows for setting the right expectations and justifying the behavior observed by users, but also because it can be used for improving the process of developing applications that use APIs offered by such services and for creating tools that facilitate this process. To fill this gap, in the first part of this thesis, we present a measurement study of the consistency of the APIs exported by four widely used Internet services, the Facebook Feed, Facebook Groups, Blogger, and Google+. To conduct this study, our work develops a simple, yet generic methodology comprising a small number of tests, which probe these services from a user perspective, and try to uncover consistency anomalies, and reports on the analysis of the data obtained from running these tests for a period of several weeks. Our measurement study shows that some of these services do exhibit consistency anomalies, including some behaviors that may appear counter-intuitive for users, such as the lack of session guarantees for write monotonicity. The results show that developers have to deal with consistency anomalies, to provide consistency guarantees they need. To address the challenge of enforcing consistency guarantees on top of existing systems, in the second part of this thesis, we show that it is possible to deploy a middleware between the application and the service, which enables a fine-grained control over the session guarantees that comprise the consistency semantics provided by these APIs, without having to gain access to the implementation of the underlying services. Our solution intercepts all interactions of the client with the online service and uses four different algorithms to enforce each of the session guarantees and also their combination. We evaluated our middleware using the Facebook public API and the Redis data store, and our results show that we are able to provide fine-grained control of the consistency semantics, while incurring in a small local storage and modest latency overhead

Portugal’s change of government puts the country firmly in uncharted territory

On 10 November, the minority government in Portugal led by Pedro Passos Coelho, which had taken power in elections in October, was effectively removed from office after losing a key vote in the Portuguese parliament. As James Dennison and Filipe Brito Bastos write, with the three main parties of the left combining to remove the government, it is expected that the next administration will be led by the Socialist Party’s leader António Costa. However they note that with the government likely to rely on the support of historically anti-euro and anti-NATO parties in the shape of the Left Bloc and Communists, Portugal has now decisively broken with the conventions that have dominated the country’s politics since the transition to democracy

How Portugal’s election resembled the UK’s general election and what both contests indicate about European politics

Portugal held parliamentary elections on 4 October, with the ruling centre-right coalition led by Prime Minister Pedro Passos Coelho winning the election, despite losing its absolute majority in parliament. James Dennison and Filipe Brito Bastos write that in many respects the Portuguese elections paralleled the general election held in the UK in May, with an incumbent conservative government managing to regain power against an opposition torn between anti-austerity and centrist policies. They argue that the results of both elections demonstrate a dilemma faced by the left in several European countries in the aftermath of the financial crisis: namely how to unite anti-austerity support while remaining electable

Cultivation of the wild seaweed Gracilaria gracilis under laboratory scale: The Effect of Light Intensity and Nutrients on Growth, Pigment and Total Soluble Protein Content

Considered primary sources of bioactive natural compounds with enormous applicability in various scientific-technological sectors, macroalgae have gained some prominence in recent years. The red macroalgae Gracilaria gracilis, one of the most dominant in worldwide cultivation systems, is fundamentally characterized not only by its high agar content, but also for its extraordinarily high phycobiliproteins (PBPs) levels endowed with a remarkable importance in the food industry, cosmetics, pharmaceuticals and in the field of bioactivities. The main objectives of this study consisted in manipulate laboratorily certain cultivation conditions of G. gracilis from the Lagoa de Óbidos (namely, light intensity and concentration of the macronutrients N and P (in the form of ammonia and phosphate, respectively)) and test their effects on growth, on the content of the Rphycoerythrin (R-PE) and R-phycocyanin (R-PC) PBPs, total soluble protein (TSP) content of the algal tissue and evaluate different methods of PBPs extraction applied to different states and pretreatments of algal biomass to assess the most effective method. As to the different extractions techniques used, for oven-dried wild samples, a maximum of 1.186 ± 0.008 mg of R-PE was obtained per g of dry weight with the bead beater, whereas enzymatic hydrolysis with cellulase only provided a maximum pigment content of 0.220 ± 0.001 mg R-PE g-1 of dry weight, clearly indicating that the first technique is much more efficient than the last one. For the wet samples, the methodology employing the tissue homogenizer yielded maximum values of 4.568 ± 1.773 mg R-PE g-1 WW and 0.099 ± 0.076 mg R-PC g -1 WW, proving that this extractingwith-water mechanical methodology is the most effective of the three in the extraction of phycobiliproteins from G. gracilis. One of the first things to note in culture assays is that light intensity and quality play a major role on the quality of the biomass and, thus, depending on the parameters desirable to increase in cultivation - DGR, PBPs or TSPs -, it may be preferable to use one or the other culture lamps tested - Cool White Fluorescent (CWF) or Plant Growth Fluorescent (Gro-Lux). The maximum DGR (16.219 ± 3.84 % day-1 ) was obtained for Gro-lux (with nutrient increment on the growth medium) while the obtained for CWF did not exceed the 14.936 ± 1.243 %, revealing a greater importance of nutrients (in particular, ammonium), comparatively to light, for this parameter. The TSPs concentration ranged from 18.06 ± 2.027 (for CWF) to 9.71 ± 0.364 % of dry weight (for Gro-lux without nutrient or light increment). As for R-PE and R-PC pigments, extracted with the tissue homogenizer, the highest peaks were obtained for CWF after two weeks of cultivation (9.599 ± 1.722 and 0.156 ± 0.043 mg g-1 of wet weight, respectively) - originated by a higher light intensity of the CWF lamp in comparison to the Gro-lux one. In sum, the similarity between the high levels of PBPs already studied in Gracilaria and the considerable levels of mechanically extracted R-PE in this study for Gracilaria gracilis, allied with an optimization of cultivation conditions (light and nutrients) to increase DGR, PBPs or TSP content in specific situations, may certainly justify the large-scale cultivation of this macroalgae species

Is centralised general data protection regulation enforcement a constitutional necessity?

Protection of personal data as a fundamental right – GDPR’s enforcement dilemma in cross-border cases – “One-stop-shop” model’s inadequacies highlighted – Distinction: regular cross-border enforcement versus cases of common European concern – Proposal: centralised enforcement mechanism for cases of common European concern – Union supervisory authority as a solution – Insufficiencies of the harmonisation proposal of the European Commission – Centralisation’s advantages: uniform enforcement, better coordination, and curbing forum shopping – Implications: fundamental rights protection and EU’s constitutional obligations – Constructive critique of the one-stop-shop model, not a dismissal – European constitutional law mandates effective data protection enforcement

Análise comparativa de aparelhos para medição de vibração em cabos condutores de energia e cálculo da vida remanescente em cabos

Monografia (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2015.O objetivo deste trabalho é estabelecer uma análise crítica sobre vibrógrafos, aparelhos utilizados para registrar parâmetros de vibração em cabos condutores de eletricidade. Para avaliar as limitações destes instrumentos, dois modelos comerciais de vibrógrafos (Pavica e Vibrec 500 WT) foram instalados na bancada de testes da Universidade de Brasília. Os registros de frequência e deslocamento efetuados pelos equipamentos foram comparados com os parâmetros de vibração monitorados por instrumentos calibrados e de alta precisão instalados na bancada de testes do laboratório. As medições de frequência efetuadas pelos aparelhos em análise corresponderam com a frequência de vibração imposta pelo shaker, no entanto, as medições de deslocamento (amplitude de flexão) não ficaram dentro dos intervalos de valores esperados. As amplitudes registradas foram menores do que os valores monitorados por meio de um acelerômetro piezoelétrico e os resultados indicam que há uma limitação dos equipamentos em registrar grandes níveis de amplitude de flexão. Dados disponíveis na literatura de um vibrógrafo instalado em uma linha de transmissão também foram utilizados para demostrar o procedimento adotado na aplicação da metodologia CIGRÉ WG-22-04, a qual conduz à estimativa da vida remanescente do cabo condutor. __________________________________________________________________________ ABSTRACTThe aim of this work is to critically analyse vibration recorders, equipments which record vibration parameters in overhead transmission lines. In order to evaluate the limitations of these instruments, two commercial models of vibration recorders (Pavica and Vibrec 500 WT) were installed in experimental fatigue workbench mounted in the University of Brasília. The records of frequency and displacement done by the equipments were compared with the vibration parameters monitored by calibrated and high precision instruments installed in the laboratory workbench. The frequency measurements done by the devices under consideration corresponded to the frequency of vibration imposed by the shaker, however, the displacement (bending amplitude) measurements were not within the range of expected values. The recorded amplitudes were lower than monitored values by a piezoelectric accelerometer and the results indicate a limitation of vibration recorders in register large levels of bending amplitude. Data available in the literature of a vibration recorder installed in an overhead line also were used to demonstrate the procedure executed in the CIGRÉ WG-22-04 methodology, which leads to predict the remaining lifetime of the conductor

Da Gallaecia a Portugal: a conceção do espaço ocidental peninsular em duas crónicas do século XIII

In the thirteenth century a new political-military scenery in the Iberian Peninsula led the most relevant Hispanic political actors to feel the need to have their actions, achievements and vision of Hispania portrayed. The historiographical discourse, somewhat ‘abandoned’ for decades, was now more than ever essential in the Iberian kingdoms’ politics. For that reason, it was resumed with great vigor in the reign of Fernando III (1217/1230-1252), precisely the monarch who reunited once again the crowns of Castile and Leon. It’s in this context that the chronicles analyzed in this study emerge – the Chronicon Mundi and the De rebus Hispanie. This study aims to analyse the views of both chronicles on the western peninsula’s space/territory and also it’s narrative process concerning what eventually became the kingdom of Portugal.No início do século XIII, um novo cenário político-militar na Península Ibérica levou a que os principais atores políticos sentissem a necessidade de enquadrar a sua atuação, bem como a sua visão da Hispania. O discurso historiográfico, de certa forma ‘abandonado’ durante décadas, torna-se central na política dos reinos ibéricos, motivo pelo qual foi retomado com grande vigor no reinado de Fernando III (1217/1230-1252), precisamente o monarca que agregou uma vez mais as coroas de Castela e Leão. É neste contexto que surgem as crónicas analisadas neste estudo – o Chronicon Mundi e o De rebus Hispanie. O presente estudo procura analisar de uma forma extensiva estas obras, nomeadamente no que diz respeito à conceção de espaço/território e também quanto à narrativa relativamente ao processo que viria a resultar na autonomia do reino de Portugal

Cimbres metálicos autolançáveis na construção de tabuleiros de pontes

Dissertação para obtenção do Grau de Mestre em Engenharia Civil - Perfil EstruturasA crescente evolução dos cimbres autolançáveis levou a que estes se tornassem estruturas cada vez mais complexas e com uma elevada versatilidade, sendo que os métodos usados no seu dimensionamento têm de acompanhar essa evolução, tornando-se cada vez mais rigorosos e criteriosos. Para tal é indispensável uma análise detalhada de todas as fases de utilização bem como das acções que intervêm na estrutura do cimbre. Nesta dissertação pretende-se descrever a estrutura dos cimbres autolançáveis de estrutura portante superior, a metodologia de funcionamento durante a fase de betonagem e de movimentação. Descrevem-se também os principais aspectos a ter em conta na manutenção da estrutura e identificam-se as acções condicionantes e a metodologia de análise e de verificação da segurança nas fases de movimentação e de betonagem. É efectuado um enquadramento histórico deste tipo estruturas na construção de pontes, que inclui uma breve descrição da evolução dos cimbres autolançáveis de estrutura portante superior, bem como a enumeração de algumas das suas principais características. São analisados vários modelos de estudo, efectuando-se para cada um deles uma análise de esforços no programa de cálculo automático SAP2000 R , os quais foram utilizados como base para a definição das acções de dimensionamento e para a verificação da segurança da estrutura do cimbre. Apresentam-se no final da dissertação as principais conclusões obtidas da realização deste trabalho e propõem-se alguns aspectos para desenvolvimentos futuros na análise da estrutura de cimbres autolançáveis de estrutura portante superior

Beyond executive federalism : the judicial crafting of the law of composite administrative decision-making

Defence date: 13 June 2018Examining Board: Professor Deirdre Curtin, European University Institute (Supervisor) ; Professor Miguel Poiares Maduro, European University Institute ; Professor Paul Craig, St. John's College, Oxford ; Professor Herwig Hofmann, University of LuxembourgThe thesis examines how EU courts have addressed the rule of law challenges of composite procedures. Composite procedures are pervasive administrative processes which involve joint decision-making by national and EU authorities. Such procedures fit poorly into the EU’s traditional model of administrative law, EU executive federalism, which is designed for an administrative system where decisional power is exercised separately by the two levels of administration. This mismatch would make it difficult to observe several key requirements of the rule of law in EU administrative law – such as the right to be heard, the right to a reasoned decision, judicial protection, and the control of legality. The thesis argues that EU courts have crafted a series of unprecedented implicit principles that specifically aim at ensuring the observance of rule of law requirements in composite decision-making. In doing so, EU case law has departed from the old doctrine of EU executive federalism. This was however not an easy transition. Indeed, since the EU’s foundational period, EU executive federalism was considered to be a constitutional doctrine, i.e., to immediately flow from the Treaties. Given the almost complete lack of references to administrative issues in the Treaties, this reading was entirely question-begging. Its espousal in the case law is explained in the dissertation as the likely result of a shared federalist conception of the European Union and of the administrative order created under its aegis. The thesis further argues that, just as the doctrine of EU executive federalism, the judge-made law of composite procedures relies on a series of assumptions on the relations between national and EU administration. The principles of composite decision-making do not treat national and EU authorities as two strictly separate spheres of power. Rather, they handle the two levels as a single, integrated administration, where national authorities are treated as an extension of the Commission – as the EU administration’s ancillary bureaucracy