Security challenges with virtualization

Tese de mestrado, Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2009Virtualização é uma palavra em voga no mundo das tecnologias de informação. Com a promessa de reduzir o constante crescimento das infra-estruturas informáticas dentro de um centro de processamento de dados, aliado a outros aspectos importantes como disponibilidade e escalabilidade, as tecnologias de virtualização têm vindo a ganhar popularidade, não só entre os profissionais de tecnologias de informação mas também administradores e directores. No entanto, o aumento da adopção do uso desta tecnologia expõe o sistema a novas preocupações de segurança que normalmente são negligenciadas. Esta tese apresenta o estado da arte das soluções actualmente mais usadas de virtualização de servidores e também um estudo literário dos vários problemas de segurança das tecnologias de virtualização. Estes problemas não são específicos em termos de produto, e são abordados no âmbito de tecnologias de virtualização. No entanto, nesta tese é feita uma análise de vulnerabilidades de duas das mais conhecidas soluções de virtualização: Vmware EXS e Xen. No final, são descritas algumas soluções para melhorar a segurança de acesso a banco online e de comercio electrónico, usando virtualização.Virtualization is a hype word in the IT world. With the promise to reduce the ever-growing infrastructure inside data centers allied to other important concerns such as availability and scalability, virtualization technology has been gaining popularity not only with IT professionals but also among administrators and directors as well. The increasingly rising rate of the adoption of this technology has exposed these systems to new security concerns which in recent history have been ignored or simply overlooked. This thesis presents an in depth state of art look at the currently most used server virtualization solutions, as well as a literature study on various security issues found within this virtualization technology. These issues can be applied to all the current virtualization technologies available without focusing on a specific solution. However, we do a vulnerability analysis of two of the most known virtualization solutions: VMware ESX and Xen. Finally, we describe some solutions on how to improve the security of online banking and e-commerce, using virtualization

Study of the light’s dazzling effect on the EEG signal of subjects performing tasks that require concentration

Tese de mestrado integrado, Engenharia Biomédica e Biofísica (Sinais e Imagens Médicas) Universidade de Lisboa, Faculdade de Ciências, 2019The objective of this work is to study the effect of luminous glare on the electroencephalographic (EEG) signals of subjects that perform concentration-based tasks. The increasing access to high-power and directional light sources (such as laser pointers, but also some flashlights) has led to a growing concern with the potential effects of its use. More than the direct damaging of the retina, the focus has been directed at the effects related to the change in states of concentration on individuals performing tasks whose concentration is critical (such as helicopter pilots or heavy vehicles drivers). This effect is known as ”dazzling” and is typically a temporary deleterious effect on the ability to see or concentrate. However, while damage to the retina can be quantified, glare effects, being indirect (based on the effect on the execution of a given task), are typically qualitative (or at least of more subjective quantification). In this context, the use of brain-computer interfaces capable of analyzing the brain response to external stimuli, opens a door towards the creation of a new tool to evaluate the effects of dazzle. Its potential was evaluated by defining a set of strategies involving the illumination process, EEG signal recording and analysis. A continuous performance task commonly used as an assessment in cognitive neuroscience (N-back) was used to test the attention under the effect of dazzling, in parallel with EEG signals acquisition. Statistical data analysis was performed with the R programming language. ANOVA statistical significant results (p<0.001) for answer scores and latency were obtained for differences between the levels of difficulty, both with or without dazzling. Tukey’s test further revealed that these statistical differences were on the 0-back/2-back and 1-back/2-back pairs (p<0.005). The differences in the pair 0-back/1-back were not significant. Peak band frequency statistical tests were not significant with or without dazzling. Statistical differences were found between dazzling conditions for the frequency band power. For the 0-back and 1-back levels, with the AF7-Fp1 electrode pair, T-student tests resulted in an alpha band frequency power increase (p<0.003, in both cases). The electrode pair AF8-Fp2 resulted in an alfa and beta frequency band increase for the 1-back level (p<0.014 and p<0.029, respectively). These results suggest that concentration is affected by dazzling and can be quantified by means of measuring the change in alpha and beta frequency band power. This technique holds potential and, if further researched and developed, may constitute an effective way of measuring the degree of loss of concentration under the effect of dazzling

Quality control and productivity in oak timber - from forest to the primary processing

Oak timber is valuated for its beauty, good mechanical properties and natural durability and may have multiple uses. An understanding of the factors that affect oak timber quality is essential. It is important to have quality control of physical, mechanical and technological wood characteristics in order to define the better primary processing and end-use. Silviculture may significantly impact wood quality and final stand value. Specific prescriptions will depend on species, site conditions, desired end product and management options. An appropriate silviculture with optimized technological operations allows a well use of wood even with small diameters. Adequate wood classification is required in order to optimize industrial processes and improve product quality. Quality criteria and procedures for round and sawtimber are referenced

Encounter management

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 200

The adoption of big data technologies - A challenge for national statistics offices

National Statistics Offices (NSOs) integrate the global statistical network system. As it happens with other organizations, NSOs need to innovate in their technological structure to keep offering timely and high-quality official data. Big Data technologies are among the most relevant to improve the performance of NSOs. However, on the one hand, there is considerable variation among NSOs regarding the adoption of these technologies, which is a matter of concern. On the other hand, the phenomenon is not being addressed in the research literature. This study outlines research that aims to contribute to the understanding of how NSO organizations adopt and disseminate Big Data technologies in their main processes, including collecting, analyzing, and providing public statistics.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scopes: UIDB/00319/2020

Evidence from electronic payments

This paper uses novel and comprehensive data on electronic payments from SIBS, the main provider of point of sale terminals and on-line payments in Portugal, to study the impact of the Great Lockdown on purchases. The data aggregates all individual transactions into monthly observations, by municipality and sector, between 2018 and 2020. We employ a difference-in-differences event study that relies on the assumption that the monthly evolution of purchases in the first four months of 2020 would be parallel to that of the two previous years. We identify a massive causal impact on overall purchases, from a baseline year-on-year monthly growth rate of 10% to a decrease of 45%. The sign and magnitude of the impact varies considerably across sectors. Purchases of essential goods such as supermarkets and groceries increase mildly, contrasting with severe contractions in sectors that were closed by government order or depend heavily on tourism, including the leisure industry and restaurants. We find suggestive evidence of initial stockpiling of goods, postponing of essential expenditures, and rapid recovery of purchases in tech and entertainment, possibly to adapt to the confinement. Transactions with foreign-owned cards cause an even greater negative contraction. We disentangle the total effect into the intensive margin of the average transaction and the extensive margin of the number of transactions. Buyers adjust their shopping strategies in rational ways to minimize public health risks: they go less often to supermarkets and buy more each time, and visit local groceries more.publishersversionpublishe

O povoado islâmico dos alcariais de Odeleite. Uma Qarya no Algarve Oriental. Primeiros resultados arqueológicos

A estação arqueológica conhecida por alcariais de Odeleite localiza-se na freguesia de Odeleite, concelho de Castro Marim e distrito de Faro – coordenadas GAUSS: X-6.34.2, Y-41.33.7, CMP 1:25.000, fl. 583, ed. 1978 (Fig. 2). Não se trata de um sítio arqueológico de todo desconhecido, tendo sido identificado por Helena Catarino em prospecções arqueológicas desenvolvidas nesta parte do Algarve Oriental, fazendo-o corresponder na periodização que elaborou sobre o povoamento rural islâmico nesta região à fase II – islâmico pleno e tardio (Catarino, 1997/98, p. 556). Trata-se de um grande povoado rural (Qarya) composto por mais de uma dezena de casas e localizado, estrategicamente, próximo da ribeira de Odeleite. Desenvolve-se ao longo do topo de cabeços relativamente elevados e ligeiramente aplanados, tendo-se confirmado a presença de núcleos habitacionais em pequenas plataformas nas encostas desses mesmos cabeços

Paradigm: a bibliometric analysis of papers presented at the conferences of the POMS from 2000 to 2010

This study presents bibliometrics on Paradigm in papers presented at the Production and Operation Management Society (POMS) from 2000 to 2010, and establishes the profile of the authors and the theoretical relationships present in those papers’ content. The portal of the Production and Operation Management Society and the abstracts contained in each of the events of the period were used, seeking to highlight the concept of Paradigm and its approaches. As a result, the articles presented at the POMS from 2000 to 2010, at least three out of the four hundred papers had the concept in its title or abstract, besides being within the central arguments of these same items analyzed by this study

Uma Avaliação à Luz da Teoria Axiomática de Projeto

Os navios da classe Viana do Castelo são navios de patrulha o ceânicos resp onsáveis p or executar missõ es no âmbito da autoridade do Estado e de interesse público, nomeadamente a busca e salvamento marítimo. Com este trabalho estud ase o sistema de climati zação instalado à luz de uma teoria de pro jeto: a Axiomática de Pro jeto. Considerando como principais funçõ es de um sistema de climatização assegurar amb ientes térmicos de conforto e ambientes interior saudáveis, foi realizado um estudo sobre estas temáticas. Relativamente ao conforto térmico aplicou-se o mo delo de Fanger, prescrito nas normas ISO 7730 e ASHRA E 55. Com este estudo inferiu-se quais as condiçõ es que garantem maior conforto térmico. Quanto à qualidade do ar, onsiderando como critério de avaliação o cau dal de ar novo, aplicou-se a norma ASHRAE 62 de forma a comparar este normativo com o atual pro jeto. Com a apl icação do primeiro axioma da axiomática: axi oma de indep endência foi p os sível concluir, dep ois de decomp or o sistema hierarquicamente, que às várias configuraçõ es do sistema instalado corresp ond iam pro jetos acoplados. Neste sentido, e tendo como base os teoremas d a teoria, foram prop ostas duas soluçõ es a que corresp on dem pro jeto d esacopl ad os . Dado que se chegaram a duas soluçõ es que do p onto de vista axiomático corresp ond iam a pro jetos desacoplados, utilizou-se o axioma da informação com o intuito de avaliar qual o sistema com menor informação e p or isso aquele que deve ser considerado o melhor pro jeto. No seguimento da avaliação descrita chegou-se à conclusão que o melhor projeto corresp ondia a um sistema com ar novo dedi cad o que utili za ventilo convectores como unidades terminais. Esta solução é a prop osta para o sistema de climatização para os futuros navios desta cl ass e. A solução prop osta tem algumas implicaçõ es em função do caudal de condensados que p o derá ser formado junto de cada bateria, p elo qu e se apresentam duas soluçõ es p or forma a resolver este probl ema.Vess el s of the Viana do Castelo’s class are o cean patrol vessels resp onsible for carrying out missions under the authority of the State and in the public interest, namely maritime search and rescue. With this work studies the air conditionin g system installed according to a pro ject theory: Axiomatic Design. Considering as the main functions of an air conditioning system to guarantee thermal comfort environments and healthy i ndo or environments in terms of ai r quality, a stu dy of thermal comfort was con ducted and ended with the application of the Fanger’s mo del, prescrib ed in ISO 7730 and ASHRAE 55, to each air conditioning zone. With this study it was inferred which conditions ensure greater thermal comfort. In terms of the air quality criteria, the dilution of indo or p ollution by the definition of the new air flow to b e inflated in each comp artment shall b e considered as a function of the system. With the application of the first axiom of axiomatic d esign: the axiom of indep endence, it was p ossible to conclude, after hierarchically decomp osing the system, that the various configurations of the installed system considered coupled pro jects. In this sen se, and based on the theorems of theory, two solutions corresp onding to uncoupled pro ject were prop osed. Given that two s olu tions were reached, that from the axiomatic p oint of vi ew corresp onded to uncoupled p ro jects, the axiom of information was us ed in order to assess which s ys tem has the leas t information, and, therefore, which should b e cons idered the b est pro ject. Following the describ ed evaluation, it was conclu ded that the b est pro ject was a dedicated outdo or air system that uses fan coils as terminal units. This is the prop osed solution for the air conditioning system for future ships of this class. The prop osed solution has some implications ab out the condensate flow th at might b e formed near the co olling coil of each fan coil, therefore are also prop osed two solutions to solve this problem. Nevertheless, since the sh ip is not a fixed platform and the insufflation air flow corresp onds to the average interior conditions, the prop osal reflects probl ems regarding the flow of condensates which may b e accumulated next to the co oling batteries of each fan coil and that may infiltrate insid e each compartment

Estudo sobre a detecção do circovirus aviário psitacídeos domésticos na região de Barcelona – Espanha

Dissertação de Mestrado Integrado em Medicina VeterináriaA dissertação aqui presente estuda pela primeira vez, a infecção pelo circovirus aviário (Beak and Feather Disease Virus - BFDV) em aves psitacídeas na região espanhola da Catalunha, entre 2005 e 2008. O BFDV provoca a doença do bico e penas dos psitacídeos (Psittacine Beak and Feather Disease - PBFD), cuja apresentação clínica depende de vários factores relativos à ave infectada, ao ambiente e ao genótipo viral. A doença é observada em aves de cativeiro de todo o mundo e em aves selvagens de África e do Pacífico, colocando em risco a conservação de algumas espécies ameaçadas. É apresentada uma revisão bibliográfica sobre o tema abordando a caracterização da doença em termos de etiologia, patogenicidade, quadros clínicos, diagnóstico, tratamento e profilaxia. Através de amostras maioritariamente sanguíneas de 1348 animais de pelo menos 83 espécies diferentes, foi testada pelo método da reacção em cadeia da polimerase (PCR) a presença do DNA viral. Os animais estudados são na esmagadora maioria nascidos em cativeiro em países europeus e residentes da região. Tendo em conta os resultados de estudos anteriores e de diferentes regiões geográficas, encontrou-se um valor de prevalência relativamente reduzido (2,60%±0,8%). Certos grupos taxonómicos revelaram maior prevalência da infecção (Ecletus sp., Agapornis sp. Ara sp. e Psittacus erithacus ssp.), enquanto noutros não se encontraram animais positivos em todo o estudo. Não foi encontrada qualquer associação estatística entre a infecção por BFDV e o sexo ou a presença de Chlamydophila sp. Foi estudado o quadro clínico de 26 animais positivos e foi possível observar que 49% não apresentavam sintomas no momento da colheita de sangue. O quadro clínico agudo apenas se observou em Psittacus erithacus ssp. e Ecletus roratus ssp.ABSTRACT - Studies on the detection of Avian Circovirus in domestic psittacines in Barcelona region - Spain - ~This dissertation studies for the first time the avian circovirus (BFDV) infection in psittacine birds in the Spanish region of Catalonia, between 2005 and 2008. BFDV is the etiologic agent of the Psittacine Beak and Feather Disease (PBFD), whose clinical presentation depends on various factors relative to the infected bird, environment and viral genotype. The disease is observed in captive birds worldwide and in wild birds in Africa and Pacific, putting at risk the conservation of some endangered species. A literature review is presented approaching the etiology, pathogenicity, clinical presentation, diagnosis, treatment, and prophylaxis. The presence of viral DNA was tested by PCR in blood samples from 1348 animals of about 83 different species. Most of the tested animals were captive born in European countries and living in Catalonia region. Comparing to other similar studies and from different geographic regions, the prevalence value was relatively low (2,60%±0,8). Certain taxonomic groups revealed higher infection prevalence (Ecletus sp., Agapornis sp., Ara sp. e Psittacus erithacus ssp.), while in other species no positive birds were found in the whole study. No statistical relation was found between BFDV infection and sex or the presence of Chlamydophila sp. The clinical presentation in 26 positive animals was studied and it was observed that 49% didn’t show any symptoms at the moment of the blood sample collection. The acute clinical presentation was observed in Psittacus erithacus ssp. and Ecletus roratus ssp. species