Även om de flesta av oss i dagsläget vet att våra mobila enheter kan tappa sina nätverksanslutningar lite då och då har det mer eller mindre blivit en självklarhet att i alla lägen ändå kunna använda våra favoritapplikationer som vanligt. Denna rapport syftade till att hitta en lösning på problemet med nätverksberoende applikationer genom att implementera ett offline-läge som kringgick detta beroende i GreatRate, en iOS-applikation för kundundersökningar i butik. Med hjälp av en databas för att mellanlagra data under tillfällen då en duglig nätverksanslutning inte fanns tillgänglig samt synkronisering av nämnda data när anslutningen åter blivit funktionell förväntades problemet kringgås. Resultatet blev som väntat en applikation som gav användaren en förhöjd användarupplevelse helt oberoende av nätverksanslutningens status. Några av slutsatserna som drogs var dock att flera olika lösningar finns för detta problem och att problemet högst troligt har olika utseenden för olika applikationer.

Ce manuscrit de thèse porte sur le problème du test basé modèle de systèmes de production existants, tels ceux de notre partenaire industriel Michelin, l’un des trois plus grands fabricants de pneumatiques au monde. Un système de production est composé d’un ensemble de machines de production contrôlées par un ou plusieurs logiciels au sein d’un atelier dans une usine. Malgré les nombreux travaux dans le domaine du test basé modèle, l’écriture de modèles permettant de décrire un système sous test ou sa spécification reste un problème récurrent, en partie à cause de la complexité d’une telle tâche. De plus, un modèle est utile lorsqu’il est à jour par rapport à ce qu’il décrit, ce qui implique de le maintenir dans le temps. Pour autant, conserver une documentation à jour reste compliqué puisqu’il faut souvent le faire manuellement. Dans notre contexte, il est important de souligner le fait qu’un système de production fonctionne en continu et ne doit être ni arrêté ni perturbé, ce qui limite l’usage des techniques de test classiques. Pour pallier le problème de l’écriture de modèles, nous proposons une approche pour construire automatiquement des modèles depuis des séquences d’événements observés (traces) dans un environnement de production. Pour se faire, nous utilisons les informations fournies par les données échangées entre les éléments qui composent un système de production. Nous adoptons une approche boîte noire et combinons les notions de système expert, inférence de modèles et machine learning, afin de créer des modèles comportementaux. Ces modèles inférés décrivent des comportements complets, enregistrés sur un système analysé. Ces modèles sont partiels, mais également très grands (en terme de taille), ce qui les rend difficilement utilisable par la suite. Nous proposons une technique de réduction spécifique à notre contexte qui conserve l’équivalence de traces entre les modèles de base et les modèles fortement réduits. Grâce à cela, ces modèles inférés deviennent intéressant pour la génération de documentation, la fouille de données, mais également le test. Nous proposons une méthode passive de test basé modèle pour répondre au problème du test de systèmes de production sans interférer sur leur bon fonctionnement. Cette technique permet d’identifier des différences entre deux systèmes de production et réutilise l’inférence de modèles décrite précédemment. Nous introduisons deux relations d’implantation : une relation basée sur l’inclusion de traces, et une seconde relation plus faible proposée, pour remédier au fait que les modèles inférés soient partiels. Enfin, ce manuscrit de thèse présente Autofunk, un framework modulaire pour l’inférence de modèles et le test de systèmes de production qui aggrège les notions mentionnées précédemment. Son implémentation en Java a été appliquée sur différentes applications et systèmes de production chez Michelin dont les résultats sont donnés dans ce manuscrit. Le prototype développé lors de la thèse a pour vocation de devenir un outil standard chez Michelin. / This thesis tackles the problem of testing (legacy) production systems such as those of our industrial partner Michelin, one of the three largest tire manufacturers in the world, by means of Model-based Testing. A production system is defined as a set of production machines controlled by a software, in a factory. Despite the large body of work within the field of Model-based Testing, a common issue remains the writing of models describing either the system under test or its specification. It is a tedious task that should be performed regularly in order to keep the models up to date (which is often also true for any documentation in the Industry). A second point to take into account is that production systems often run continuously and should not be disrupted, which limits the use of most of the existing classical testing techniques. We present an approach to infer exact models from traces, i.e. sequences of events observed in a production environment, to address the first issue. We leverage the data exchanged among the devices and software in a black-box perspective to construct behavioral models using different techniques such as expert systems, model inference, and machine learning. It results in large, yet partial, models gathering the behaviors recorded from a system under analysis. We introduce a context-specific algorithm to reduce such models in order to make them more usable while preserving trace equivalence between the original inferred models and the reduced ones. These models can serve different purposes, e.g., generating documentation, data mining, but also testing. To address the problem of testing production systems without disturbing them, this thesis introduces an offline passive Model-based Testing technique, allowing to detect differences between two production systems. This technique leverages the inferred models, and relies on two implementation relations: a slightly modified version of the existing trace preorder relation, and a weaker implementation proposed to overcome the partialness of the inferred models.Overall, the thesis presents Autofunk, a modular framework for model inference and testing of production systems, gathering the previous notions. Its Java implementation has been applied to different applications and production systems at Michelin, and this thesis gives results from different case studies. The prototype developed during this thesis should become a standard tool at Michelin.

The purpose of the paper is to give a detailed description to provide a better understanding of what strategies women use when online dating and in real life. The purpose of the paper is to identify how women create a sense of security for themselves, to make the leap from online communication to meeting an unknown male in the real world. For those two unknown people to take the step to meet each other face to face, there should be a kind of trust between them, how it is created, and what factors it is that determines that a meeting in real life will take place. In this essay, it has applied a qualitative method along with six thematically open interviews in which the informants have been women aged 20-30 years. In order to analyze the empirical approach, Sztompkas and Giddens's theory of trust and security have been used together along side Goffmans concept of front and backstage and other concepts are included as well. An analysis of the empirical material was found, the results showing that women often use fairly common strategies to create security in itself. These were as such, selecting a meeting place that is public and collecting information about the person they are meeting in advance using other channels of social media such as Facebook,Tinder, etc. This indicates that there is a general underlying concern about who the person really is on the other side of the computer screen/mobile screen. It also shows that the women are consciously or subconsciously using strategies to build up a sense of security among themselves before meeting with an unknown male. Keywords: Back stage, front stage, online dating, offline, online, role, security, social interaction, Tinder och trust. / Syftet med undersökningen är att bidra med en ökad förståelse för vilka strategier unga kvinnor använder sig av vid nätdejting, online kontra offline. Syftet med uppsatsen ligger i att identifiera hur kvinnor skapar en trygghet för sig själva för att ta steget från online till att träffa en okänd man i verkligheten. För att två okända människor ska våga träffa varandra ansikte mot ansikte bör det finnas en slags trygghet mellan dem, hur skapas den och vilka faktorer är det som avgör att ett möte i verkligheten sker? I den här uppsatsen har det tillämpats en kvalitativ metod tillsammans med sex tematiskt öppna intervjuer där informanterna har varit kvinnor i åldrarna 20-30 år. För att kunna analysera empirin har Piotr Sztompkas och Anthony Giddens teorier om trygghet och tillit använts i kombination med Erving Goffmans begrepp om frontstage och backstage samt andra som inbegrips i dessa. Genom en analys av det empiriska materialet påträffades resultat som visar på att kvinnor ofta använder sig av någorlunda gemensamma strategier för att skapa trygghet för sig själva, dessa var exempelvis: att välja en mötesplats som är offentlig, samla information i förväg om personen, användningen av andra kommunikationskanaler utöver Tinder etc. Detta pekar på att det överlag finns en underliggande oro för vem personen är på andra sidan datorskärmen/mobilskärmen, samt att personer omedvetet eller medvetet använder strategier för att bygga upp en trygghet hos sig själv innan mötet med en okänd människa. Nyckelord: Backstage, fasad, frontstage, inramning, nätdejting, offline, online, roll, social interaktion, tillit, Tinder och trygghet.

Malgré une littérature abondante sur les conséquences des technologies de l'information et de la communication (TIC), cette littérature n'aborde que trop peu les conséquences sociétales, qu'elles soient positives ou négatives, intentionnelles ou non. Parce que les interactions se propagent au-delà de l'espace en ligne et de ces conséquences paradoxales, les défis sociétaux sont un problème complexe. C'est pour ces raisons que nous avons besoin d'une meilleure compréhension des problèmes sociaux complexes. Pour ce faire, nous avons adopté le modèle de la thèse sur travaux. Les trois études de ce travail de doctorat adoptent une approche qualitative et un positionnement réaliste critique. Nous examinons un premier cas : celui du Printemps Arabe et l'utilisation de Facebook. Etudier ces types d'événements contemporains ne vient pas sans difficultés analytiques. Par conséquent, nous utilisons un outil d'analyse sémiotique pour faire face à la complexité représentationnelle des données recueillies. Enfin, les communautés en ligne peuvent également générer des coûts sociaux en fournissant un espace se faisant l'écho à des comportements socialement indésirables. / Despite the wide literature on the consequences of Information and Communication Technologies (ICTs) use, the literature still lacks understanding about the societal consequences, positive or negative, intended or unintended. Consequences of technology usages on society are paradoxical. The paradoxical outcomes can be threat to the sustainability of society. Because interactions spread beyond the online space and its outcomes are paradoxical, societal challenges are complex problem. To harvest society, we need a better understanding of social complex problems. To do so, we adopted a multi-study dissertation model. The three studies of this doctoral work adopt a qualitative approach and a critical realist philosophy.We look at a first case: The Arab Spring and aim at understanding how an online community that started on Facebook materialized in urban space, changing the political landscape. Addressing these contemporaneous events does not come without analytical challenges. Therefore, we use and extend a semiotic analytical tool to face the representational complexity: Finally, online communities can also have social costs by providing an echo chamber to socially undesirable behaviors.

Physical access control systems (PACS) deal with the security of the availability of resources. They work as an alternative to traditional manual security access control. Access control has two variants, the logical which deals with computer environments and the physical which deals with the physical entry into a property or warehouses. However, offline physical access control systems cannot enforce the user’s path making it unsuitable for use in classified areas, such as places where the public is restricted. Therefore, offline PACS need a framework that can delegate the authority to enforce the user’s path. This is satisfactorily met in the presented research with a new design of offline PACS that has the capability to implement delegation. This framework allows the locks to dynamically write and read access policies onto and from a smart card. It works by means of a construct called “Path Array” and communication among different entities occurs via a chain of trust formed with the use of pre-shared keys.

<p>The prevalence of offline password attacks, resulting from attackers breaching authentication servers and stealing cryptographic password hashes, poses a significant threat. Users' tendency to select weak passwords and reuse passwords across multiple accounts, coupled with computation advancement,  further exacerbate the danger.</p> <p><br></p> <p>This dissertation addresses this issue by proposing password authentication mechanisms that aim to minimize the number of compromised passwords in the event of offline attacks, while ensuring that the server's workload remains manageable. Specifically, we present three mechanisms: (1) DAHash: This mechanism adjusts password hashing costs based on the strength of the underlying password. Through appropriate tuning of hashing cost parameters, the DAHash mechanism effectively reduces the fraction of passwords that can be cracked by an offline password cracker. (2) Password Strength Signaling: We explore the application of Bayesian Persuasion to password authentication. The key idea is to have the authentication server store a noisy signal about the strength of each user password for an offline attacker to find. We demonstrate that by appropriately tuning the noise distribution for the signal, a rational attacker will crack fewer passwords. (3) Cost-Asymmetric Memory Hard Password Hashing: We extend the concept of password peppering to modern Memory Hard password hashing algorithms. We identify limitations in naive extensions and introduce the concept of cost-even breakpoints as a solution. This approach allows us to overcome these limitations and achieve cost-asymmetry, wherein the expected cost of validating a correct password is significantly smaller than the cost of rejecting an incorrect password.</p> <p><br></p> <p>When analyzing the behavior of a rational attacker it is important to understand the attacker’s guessing curve i.e., the percentage of passwords that the attacker could crack within a guessing budget B. Dell’Amico and Filippone introduced a Monte Carlo algorithm to estimate the guessing number of a password as well as an estimate for the guessing curve. While the estimated guessing number is accurate in expectation the variance can be large and the method does not guarantee that the estimates are accurate with high probability. Thus, we introduce Confident Monte Carlo as a tool to provide confidence intervals for guessing number estimates and upper/lower bound the attacker’s guessing curves.</p> <p><br></p> <p>Moreover, we extend our focus beyond classical attackers to include quantum attackers. We present a decision-theoretic framework that models the rational behavior of attackers equipped with quantum computers. The objective is to quantify the capabilities of a rational quantum attacker and the potential damage they could inflict, assuming optimal decision-making. Our framework can potentially contribute to the development of effective countermeasures against a wide range of quantum pre-image attacks in the future.</p>

This study has examined if there is a correlation between Offline Social Network and voting participation in the European Parliamentary elections. The study has been done through a qualitative method, doing five different deep interviews. The selection has been based upon the group of first generation immigrants coming from a non-EU European country. The study has showed indications that level of education, participation in associations and participation in social activities are affecting the Offline Social Network of a person. The different Offline Social Networks have shown upon different attitudes towards voting politically. It also showed upon different levels of knowledge about the European Union politics and the elections to the European Parliament. The study showed that the number of Offline Social Networks might not be what affects whether the respondents are voting or not, it shows to be rather connected to what kind of social networks. This have been connected to the field-theory of Bourdieu, which claims that a person´s habitus is affected by the volume of for example cultural and social capital which also seems to have an effect on what Offline Social Network that the individual is connected to. The way that a person appears in the social room is affected by the volume of capital and how the social room is letting the individual appear. This shows to affect whether someone votes or not.

En undersökning av vindturbiners hydraulolja med avseende på partikelinnehåll har genomförts. Med syftet att öka tillgängligheten på Statkrafts vindturbiner genom ändrade underhållsrutiner. Målsättningen har varit att minska mängden partiklar och hitta en lösning för förbättrat underhåll rörande hydrauloljan. För att lösa detta har en litteraturstudie, intervjuer och oljeprovtagning genomförts. Vidare installerades ett offlinefilter för att undersöka en potentiell lösning för partikelavskiljning och förändring av underhållsrutiner. Resultaten från oljeprovtagningen visade på höga halter av partiklar för de små och medelstora partiklarna, en låg viskositet och höga värden av föroreningar och vatteninnehåll. Samtliga parametrar förbättrades efter 24 timmar filtrering där partikelinnehållet hade minskat till godtyckliga värden tillsammans med vatteninnehållet samt att viskositeten hade en liten ökning. Efter filtrering i en vecka hade vissa av värdena gått upp ytterligare och partikelhalterna för små och medelstora partiklar hade ökat. Detta tros bero på provtagning i samband med återföring av smutsig olja från pitchcylindrarna. Lösningar på reningen av oljan undersöktes potentiellt att vara filtrering, partikelräknare, IR termografi och oljebyte. Där filtrering i kombination med partikelräknare i dagsläget ger det mest ekonomiska och lämpliga lösningen för företagets underhållsstrategi och målsättning. Slutsatsen från arbetet är att offlinefiltreringen fungerar och att underhållsrutinerna skulle kunna optimeras ytterligare om partikelräknare installerades i anslutning till detta. Ekonomiskt är denna lösning realistisk men för att göra större ändringar i underhållsrutinerna behövs vidare studier av filtreringstid och eventuellt manuell hantering / An investigation has been done of the particles in hydraulic oil in wind turbines. The purpose of this has been to increase the availability for Statkraft´s wind turbines through changing their maintenance routines. The goal has been to lower the particle count and finding a solution for bettering their maintenance with the hydraulic oil. A literature study, interviews and testing of the hydraulic oil has been done to solve this. Furthermore, an offline filtration unit has been mounted to investigate whether that may be a potential solution for clearing the oil from particles and if it can be useful for changing the maintenance routines within the oil service. The results from the oil analysis showed upon high particle counts for the smaller and middle-sized particles, low viscosity and high values for contamination and water content. All parameters were improved after 24 hours of filtration where the particle count had lowered to arbitrary values together with the water count and the viscosity had a slight increase. After filtration for a week some of the parameters had gone up slightly and the values for small and middle-sized particles hade increased. This is believed to be due to oil testing at the same time as the returning of the unclean oil from the pitch cylinders. Different solutions for clearing the oil were investigated, such as filtration, a particle counter and an oil change. The result from the investigation showed that filtration together with a particle counter is the best solution. This fits both economically and the goal for the business as of today. The conclusion of this work is that the offline filtration works and that the availability routines could be optimized further if a particle counter was to be installed together with the filtration unit. Economically this solution is most realistic but to be able to do any improvements on the availability routines further investigation of the filtration intervals has to be done with potential manual labour

No description available.

Programming industrial robots for welding or part manipulation tasks is a time-consuming and complicated process, resulting in companies not able to implement robot systems and exploit their advantages. To reduce the time needed for programming, research is looking into ways to automate this process and reduce manual labour.In this thesis a concept for automating the programming process of industrial robots was investigated using EXCEL VBA and CATIA/DELMIA. It was done for an industrial grating model of varying sizes and configurations, resulting in a time reduction of 99% compared to manual creation. For this, the model was first automatically created from scratch for the required configuration and afterwards a robot motion was created fully automatically. The concept and modelling approach is described, and the automation approach detailed. Finally, the results are analysed and discussed.