Much previous work on air pollution epidemiology has studied end-stage outcomes such as mortality or severe ill health warranting emergency admission, often based on clinical criteria prone to misclassification, and usually without accompanying study of the mediating mechanisms. Therefore this work has three specific objectives: firstly, to assess the effects of short-term exposure to particles and gases on acute coronary syndrome (ACS), by measuring the levels of cardiac troponin T (cTnT), a highly sensitive and specific marker of myocardial damage in patients admitted to hospital for chest pain of myocardial origin; secondly, to investigate the effects of short-term changes in ambient air pollution on the occurrence of transient ischaemic attacks (TIA); finally, to investigate the effects of ambient and personal exposure to air pollutants on a range of mediators or markers in a putative susceptible population. Two case-crossover studies were conducted to study the association between short-term changes in air pollutants and ischaemic cardiac events and TIA. Hospital data on admissions were analysed for actual or suspected ischaemic events and the associated cTnT levels were obtained. For the TIA project, data on 709 subjects were obtained from five TIA centres clustered around Manchester and Liverpool. In the third project a panel of 35 type 2 diabetes mellitus patients were prospectively followed fortnightly for a total of four visits. At each visit blood was collected to measure markers of inflammation, coagulation and endothelial function. In all three projects ambient air pollution data were obtained from background monitoring networks and in the third project personal exposure to PM2.5 was measured. Project 1: Of 28,622 admissions, 17.5% were ACS with myocyte necrosis (cTnT 0.03-1ng/ml) and 1004 (3.5%) were cases of myocardial infarction (cTnT ≥ 1 ng/ml). Both particulate and gaseous pollutants were associated with admission for ACS. The two largest effects per interquartile increase of exposure were observed with PM10 with ORof 1.14 (95% CI: 1.05-1.24) and with SO2, OR 1.11 (95% CI: 1.00-1.23). Associations between pollution and ACS admissions were the strongest for women, those above the age of 65 years and in the cooler season. Project 2: In the Manchester dataset, exposure to nitric oxide (NO) was associated with occurrence of TIA, while no effect was observed for Liverpool data. Subgroup analysis reveals that CO, NO and NO2 were more strongly related to the occurrence of TIA in participants above the age of 65 years and male patients. Project 3: No consistent association was observed between measured biomarkers and air pollutants using exposure data from ambient monitoring stations. In contrast, significant association between personal PM2.5 and interleukin-6 (IL-6) was observed. Similarly, personal PM2.5 had large but non-significant positive associations with high sensitivity C-reactive protein and fibrinogen. The results of this study reveal that short-term changes in particulate and gaseous pollution are related to the risk of admission for ACS as demonstrated by a specific marker hitherto not used for this purpose. It provides limited evidence for an association between changes in ambient NO concentration (which may have been a surrogate for another pollutant), and the occurrence of TIA, which had not previously been studied as an air pollution outcome, and increase in IL-6, a major pro-inflammatory marker. The IL-6 response to personal PM2.5 provides evidence in support of the link between ambient levels of particles/gases and cardiopulmonary morbidity and mortality.

This report is the result of a sub-project of a larger project to create a platform formathematical education. The sub-project focuses on authentication with associ-ated security, where security is emphasized. The project environment is Java EE 6where GlassFish 4.0 acts as the server. The project has been divided into threeparts; password encryption, Java EE authentication and brute force attack. Thepassword encryption part focuses on examining different hash functions executionspeed, the result shows that none of the examined hash algorithms is suitable fordirect use. Instead its recommended to use PBKDF2 with salt to encrypt pass-words. The Java EE section constructs a working application where users can reg-ister and login etc. This is performed as a study of the security tools available inJava EE. The result meets the requirement specification and a section on Java EEsecurity tools is presented. The brute force attack section is a theoretical study ofwhat can be done to protect against a brute force attack. The result shows thatCAPTCHAs is not recommended by OWASP and a system using cookies and aform of userblocking is purposed. The various parts are separated as far as possi-ble through the report with the exception that the result of the password encryp-tion section is applied in the Java EE application. / Denna rapport är resultatet av en deluppgift i ett större projekt att skapa en platt-form för undervisning av matematik. Uppgiften fokuserar på inloggning med till-hörande säkerhet. Projektets miljö är Java EE 6 med Glassfish 4.0 som server.Projektet har delats upp i tre underkategorier; Lösenordskryptering, Java EE in-loggning och Brute force attacks. Lösenordskrypterings delen fokuserar på att un-dersöka olika hashfunktioners exekveringshastighet, resultatet visar att ingen avde algoritmer som undersöks lämpar sig att användas direkt. Istället rekommende-ras system som PBKDF2 med SALT för att kryptera lösenord. Java EE avsnittetkonstruerar en fungerande applikation där användare kan registrera sig och loggain med mera. Arbetet utförs som en studie av vilka säkerhetsverktyg som finnstillgängliga i Java EE. Resultatet uppfyller kravspecifikationen och ett avsnitt omJava EEs verktyg presenteras. Brute force attack-avsnittet är en teoretisk studieav vad som kan göras för att skydda sig mot Brute force attacker. Resultatet visaratt robotfilter inte är rekommenderat av OWASP och ett förslag på ett system somanvänder kakor och en form av användarblockering presenteras. De olika delarnaär separerade så långt som möjligt genom rapporten med undantaget att resultatetav lösenordskrypterings avsnittet tillämpas i Java EE applikationen.

Abstract In the last decades, face recognition systems have evolved a lot in terms of performance. As a result, this technology is now considered as mature and is applied in many real world applications from border control to financial transactions and computer security. Yet, many studies show that these systems suffer from vulnerabilities to spoofing attacks, a weakness that may limit their usage in many cases. A face spoofing attack or presentation attack occurs when someone tries to masquerade as someone else by presenting a fake face in front of the face recognition camera. To protect the recognition systems against attacks of this kind, many face anti-spoofing methods have been proposed. These methods have shown good performances on the existing face anti-spoofing databases. However, their performances degrade drastically under real world variations (e.g., illumination and camera device variations). In this thesis, we concentrate on improving the generalization capabilities of the face anti-spoofing methods with a particular focus on the texture based techniques. In contrast to most existing texture based methods aiming at extracting texture features from gray-scale images, we propose a joint color-texture analysis. First, the face images are converted into different color spaces. Then, the feature histograms computed over each image band are concatenated and used for discriminating between real and fake face images. Our experiments conducted on three color spaces: RGB, HSV and YCbCr show that extracting the texture information from separated luminance chrominance color spaces (HSV and YCbCr) yields to better performances compared to gray-scale and RGB image representations. Moreover, to deal with the problem of illumination and image-resolution variations, we propose to extract this texture information from different scale images. In addition to representing the face images in different scales, the multi-scale filtering methods also act as pre-processing against factors such as noise and illumination. Although our obtained results are better than the state of the art, they are still far from the requirements of real world applications. Thus, to help in the development of robust face anti-spoofing methods, we collected a new challenging face anti-spoofing database using six camera devices in three different illumination and environmental conditions. Furthermore, we have organized a competition on the collected database where fourteen face anti-spoofing methods have been assessed and compared. / Tiivistelmä Kasvontunnistusjärjestelmien suorituskyky on parantunut huomattavasti viime vuosina. Tästä syystä tätä teknologiaa pidetään nykyisin riittävän kypsänä ja käytetään jo useissa käytännön sovelluksissa kuten rajatarkastuksissa, rahansiirroissa ja tietoturvasovelluksissa. Monissa tutkimuksissa on kuitenkin havaittu, että nämä järjestelmät ovat myös haavoittuvia huijausyrityksille, joissa joku yrittää esiintyä jonakin toisena henkilönä esittämällä kameralle jäljennöksen kohdehenkilön kasvoista. Tämä haavoittuvuus rajoittaa kasvontunnistuksen laajempaa käyttöä monissa sovelluksissa. Tunnistusjärjestelmien turvaamiseksi on kehitetty lukuisia menetelmiä tällaisten hyökkäysten torjumiseksi. Nämä menetelmät ovat toimineet hyvin tätä tarkoitusta varten kehitetyillä kasvotietokannoilla, mutta niiden suorituskyky huononee dramaattisesti todellisissa käytännön olosuhteissa, esim. valaistuksen ja käytetyn kuvantamistekniikan variaatioista johtuen. Tässä työssä yritämme parantaa kasvontunnistuksen huijauksen estomenetelmien yleistämiskykyä keskittyen erityisesti tekstuuripohjaisiin menetelmiin. Toisin kuin useimmat olemassa olevat tekstuuripohjaiset menetelmät, joissa tekstuuripiirteitä irrotetaan harmaasävykuvista, ehdotamme väritekstuurianalyysiin pohjautuvaa ratkaisua. Ensin kasvokuvat muutetaan erilaisiin väriavaruuksiin. Sen jälkeen kuvan jokaiselta kanavalta erikseen lasketut piirrehistogrammit yhdistetään ja käytetään erottamaan aidot ja väärät kasvokuvat toisistaan. Kolmeen eri väriavaruuteen, RGB, HSV ja YCbCr, perustuvat testimme osoittavat, että tekstuuri-informaation irrottaminen HSV- ja YCbCr-väriavaruuksien erillisistä luminanssi- ja krominanssikuvista parantaa suorituskykyä kuvien harmaasävy- ja RGB-esitystapoihin verrattuna. Valaistuksen ja kuvaresoluution variaation takia ehdotamme myös tämän tekstuuri-informaation irrottamista eri tavoin skaalatuista kuvista. Sen lisäksi, että itse kasvot esitetään eri skaaloissa, useaan skaalaan perustuvat suodatusmenetelmät toimivat myös esikäsittelynä sellaisia suorituskykyä heikentäviä tekijöitä vastaan kuten kohina ja valaistus. Vaikka tässä tutkimuksessa saavutetut tulokset ovat parempia kuin uusinta tekniikkaa edustavat tulokset, ne ovat kuitenkin vielä riittämättömiä reaalimaailman sovelluksissa tarvittavaan suorituskykyyn. Sen takia edistääksemme uusien robustien kasvontunnistuksen huijaamisen ilmaisumenetelmien kehittämistä kokosimme uuden, haasteellisen huijauksenestotietokannan käyttäen kuutta kameraa kolmessa erilaisessa valaistus- ja ympäristöolosuhteessa. Järjestimme keräämällämme tietokannalla myös kansainvälisen kilpailun, jossa arvioitiin ja verrattiin neljäätoista kasvontunnistuksen huijaamisen ilmaisumenetelmää.

Syftet med denna studie var att beskriva hur fysiskt aktiva personer som fått diagnosen TIA var. Frågeställningarna rörde vilka aktiviteter studiedeltagarna ägnade sig åt, hur de upplevde sin hälsa, begränsande faktorer, eventuell förändring av aktivitetsvanor, samt om deltagarna fått råd om fysisk aktivitet. Som metod valdes enkätundersökning och 195 enkäter skickades till personer som sökt Universitetssjukhuset Örebro 2007 och fått diagnosen TIA. Resultat: Svarsfrekvensen, efter externt och internt bortfall, blev 74 %. Mer än hälften av de 144 studiedeltagarna var fysiskt aktiva mindre än 30 minuter/dag. Den vanligaste aktiviteten var promenader, vilket 72 % ägnade sig åt. Yngre personer ägnade sig oftare åt tre eller fler aktiviteter jämfört med äldre personer. De deltagare som var regelbundet fysiskt aktiva skattade sin hälsa som god till utmärkt, medan de med stillasittande fritid skattade sin hälsa som någorlunda eller dålig. De mest begränsande faktorerna var sjukdom och smärta. Av studiedeltagarna uppgav 98 personer att de inte fått råd om fysisk aktivitet och hälften av deltagarna hade inte förändrat sina aktivitetsvanor. Slutsats: Studien visar att många personer som fått diagnosen TIA är fysiskt inaktiva. Begränsande faktorer, som, sjukdom, smärta och hög ålder, medför att råd om fysisk aktivitet bör vara individanpassade. Att ge råd om fysisk aktivitet på lämplig nivå, utifrån den enskilde personens förutsättningar är ett centralt kunskapsområde för sjukgymnaster. Därför bör dessa patienter ges möjlighet att träffa sjukgymnast.

Dans les systèmes d'informations, les outils de détection produisent en continu un grand nombre d'alertes.Des outils de corrélation permettent de réduire le nombre d'alertes et de synthétiser au sein de méta-alertes les informations importantes pour les administrateurs.Cependant, la complexité des règles de corrélation rend difficile leur écriture et leur maintenance.Cette thèse propose par conséquent une méthode pour générer des règles de corrélation de manière semi-automatique à partir d’un scénario d’attaque exprimé dans un langage de niveau d'abstraction élevé.La méthode repose sur la construction et l'utilisation d’une base de connaissances contenant une modélisation des éléments essentiels du système d’information (par exemple les nœuds et le déploiement des outils de détection). Le procédé de génération des règles de corrélation est composé de différentes étapes qui permettent de transformer progressivement un arbre d'attaque en règles de corrélation.Nous avons évalué ce travail en deux temps. D'une part, nous avons déroulé la méthode dans le cadre d'un cas d'utilisation mettant en jeu un réseau représentatif d'un système d'une petite entreprise.D'autre part, nous avons mesuré l'influence de fautes touchant la base de connaissances sur les règles de corrélation générées et sur la qualité de la détection. / Information systems produce continuously a large amount of messages and alerts. In order to manage this amount of data, correlation system are introduced to reduce the alerts number and produce high-level meta-alerts with relevant information for the administrators. However, it is usually difficult to write complete and correct correlation rules and to maintain them. This thesis describes a method to create correlation rules from an attack scenario specified in a high-level language. This method relies on a specific knowledge base that includes relevant information on the system such as nodes or the deployment of sensor. This process is composed of different steps that iteratively transform an attack tree into a correlation rule. The assessment of this work is divided in two aspects. First, we apply the method int the context of a use-case involving a small business system. The second aspect covers the influence of a faulty knowledge base on the generated rules and on the detection.

In ad hoc networks every device is responsible for its own basic computer services, including packet routing, data forwarding, security, and privacy. Most of the protocols used in wired networks are not suitable for ad hoc networks, since they were designed for static environments with defined borders and highly specialized devices, such as routers, authentication servers, and firewalls. This dissertation concentrates on the achievement of privacy-friendly identifiersand anonymous communication in ad hoc networks. In particular, the objective is to offer means for better anonymous communication in such networks. Two research questions were formulated to address the objective: I. How to design proper and trusted privacy-friendly digital identifiers to beused in ad hoc network environments? II. How to provide anonymous communication in ad hoc networks and whatis the performance cost in relation to the obtained degree of anonymity? To address the first research question we studied and classified the security and privacy threats, enhancements, and requirements in ad hoc networks and analyzed the need for privacy and identification. The analysis led us to the relationship between security, identification, and anonymous communication that we refer to as the “identity-anonymity paradox”. We further identifiedthe requirements for privacy-friendly identifiers and proposed the self-certified Sybil-free pseudonyms to address such requirements. The second research question was addressed with the design and implementation of the Chameleon protocol, an anonymous communication mechanism for ad hoc networks. The performance of Chameleon was evaluated using a network simulator. The results were used to find out the trade-off between anonymity and performance in terms of the expected end-to-end delay. The solutions proposed in this dissertation are important steps towards the achievement of better anonymous communications in ad hoc networks andcomplement other mechanisms required to prevent leaks of personal data.

The linear feedback shift-register is a widely used tool for generating cryptographic sequences. The properties of the Galois model discussed here offer many opportunities to improve the implementations that already exist. We explore the overall properties of the phases of the Galois model and conjecture a relation with modular Golomb rulers. This conjecture points to an efficient method for constructing non-linear filtering generators which fulfil Golic s design criteria in order to maximise protection against his inversion attack. We also produce a number of methods which can improve the rate of output of sequences by combining particular distinct phases of smaller elementary sequences.

The goal of this study was to derive a clinical prediction rule for transient ischemic attack (TIA) and non-disabling stroke to predict a treatment change based on echocardiogram. Methods: We conducted a cohort sub-study for TIA and non-disabling stroke patients collected over five years from 8 Emergency Departments. We compiled a list of 27 potential predictors to look for treatment change based on echocardiogram findings. We used a univariate, logistic regression and recursive partitioning analysis to develop the final prediction model. Results: The frequency of treatment change was seen in 87 (3.1%) of 2804 cases. The final model contains six predictors: age less than 50 years old, coronary artery disease history, history of heart failure, any language deficit, posterior circulation infarct and middle cerebral artery infarct on neuroimaging. Conclusions: We have developed a highly sensitive clinic prediction rule to guide in the use of echocardiogram in TIA and non-disabling stroke.

This thesis deals with the issue of cyber security in enterprises. The main objective of this thesis is to compile a comprehensive overview of the issue of cyber security related to the Czech business entities. It is written in the context in Czech language and in less technical form. This thesis first identifies the current cyber threats, supported by examples of actual incidents. On the basis of the threats thesis defines the categories of business entities that are vulnerable to the threats, and with regard to the Czech legal system analyzes cybersecurity responsibilities. Above the legal obligations there are recommended measures and types of security tests that can check the level of cybersecurity. The output is also a methodological tool for better understanding of cyber security in companies which summarize acquired information and context in comprehensive tables. The expected contribution of this thesis is that summarized findings will serve to increase the level of IT security for Czech businesses.

Les bétons autoplaçants (BAP) se distinguent des bétons ordinaires (BO) ou vibrés, par leurs propriétés à l’état frais. Ils sont capables de s’écouler sous leur propre poids, quelque soit le confinement du milieu, et restent homogènes au cours de l’écoulement. Pour parvenir à ce cahier de charge, les BAP sont formulés différemment des BO. En général, ils possèdent un même dosage en ciment et en eau que les BO ainsi qu’un volume de sable assez proche. L’apport de la pâte (ciment + eau + adition) est privilégié au détriment des gravillons. L’objectif du travail de recherche présenté dans cette thèse porte sur l’effet de l’attaque sulfatique externe sur les bétons autoplaçants. Pour cela quatre types de bétons autoplaçants à base de ciments, de granulats concassés et d’adjuvants ont été confectionnés. Chaque béton a subit quatre protocoles différents d’attaque sulfatique externe à savoir l’immersion totale, l’immersion-séchage à 105°C, l’immersion-séchage à 60°C et l’exposition des éprouvettes à un brouillard salin. Ces ambiances visent à reproduire de manière accélérée les différentes sources de pollutions capables de générer des attaques sulfatiques externes. A terme de six mois d’exposition des échantillons en béton et en mortier, il a été possible de dresser les principales conclusions reposant sur des études macroscopiques et microscopiques des échantillons testés. Trois comportements différents des bétons ont pu êtres distingués : bétons résistent à l’attaque sulfatique externe, bétons endommagés suite à cette attaque et bétons endommagés par la précipitation des sels et non par une réaction sulfatique externe. En conclusion, cette recherche a permis d’identifier les protocoles accélérés les plus adaptés aux études de la durabilité des bétons et de classer les bétons autoplaçants confectionnés avec des granulats concassés selon leurs résistants aux attaques sulfatiques externes (pollutions industrielles ou construction sur des sols gypseux). / The aim of the presented research in this thesis focuses on the effect of external sulfate attack on the durability of self-compacting concrete. For that, four types of concretes based on Aigerian cement, crushed aggregates and plasticizers have been made. Each type of concrete has undergone four different protocols of external sulfate attack which are the total immersion, the immersion 1drying at 105 CC, the immersion 1drying at 60 CC and the exposure of specimens to a salt spray. These environments are designed to reproduce the different accelerated sources of pollution that can generate external sulfate attack. A term of six months of exposure of the samples in concrete and mortar, it was possible to draw the main conclusions based on macroscopic and microscopie studies of the sam pies tested. Three different behaviors of concrete have been distinguished: concrete resistant to external sulfate attack, concrete damaged after tis attack and concrete damaged by salt precipitation and not by external sulfate reaction.