<p>This study focuses on cell phone usage. By comparing how a group of students use their cell phones in Sweden with that in China, alterant cell phone usage behaviors will be concluded. The study includes a case study. In order to do the research, the author selects a specific group and holds interviews. Three theories are used in this thesis which are: 1) mobile context, 2) switching behavior of mobile users and 3) transaction utility and reference situation. After introducing these three theories, the author concludes six theoretical factors which are combined into one competent framework. Base on the new framework, the author analyzes the result from the case study. After presenting the interview and the results, the author finds that Chinese students use their cell phones less frequent in Sweden compared to that in China. In order to find out the reasons, the author creates goal, emotion, fee, location and habit as the five matching factors which result in those changes. The matching factors are the bridge between the theories and the case study. After generalizing how those factors affect people while using cell phones, future work is to raise up some thoughts of how cell phones will be like in the future which is relevant to how to adapt information technology to human lives.</p>

No / Mobile social networks (MSNs) facilitate connections between mobile users and allow them to find other potential users who have similar interests through mobile devices, communicate with them, and benefit from their information. As MSNs are distributed public virtual social spaces, the available information may not be trustworthy to all. Therefore, mobile users are often at risk since they may not have any prior knowledge about others who are socially connected. To address this problem, trust inference plays a critical role for establishing social links between mobile users in MSNs. Taking into account the nonsemantical representation of trust between users of the existing trust models in social networks, this paper proposes a new fuzzy inference mechanism, namely MobiFuzzyTrust, for inferring trust semantically from one mobile user to another that may not be directly connected in the trust graph of MSNs. First, a mobile context including an intersection of prestige of users, location, time, and social context is constructed. Second, a mobile context aware trust model is devised to evaluate the trust value between two mobile users efficiently. Finally, the fuzzy linguistic technique is used to express the trust between two mobile users and enhance the human's understanding of trust. Real-world mobile dataset is adopted to evaluate the performance of the MobiFuzzyTrust inference mechanism. The experimental results demonstrate that MobiFuzzyTrust can efficiently infer trust with a high precision.

This study focuses on cell phone usage. By comparing how a group of students use their cell phones in Sweden with that in China, alterant cell phone usage behaviors will be concluded. The study includes a case study. In order to do the research, the author selects a specific group and holds interviews. Three theories are used in this thesis which are: 1) mobile context, 2) switching behavior of mobile users and 3) transaction utility and reference situation. After introducing these three theories, the author concludes six theoretical factors which are combined into one competent framework. Base on the new framework, the author analyzes the result from the case study. After presenting the interview and the results, the author finds that Chinese students use their cell phones less frequent in Sweden compared to that in China. In order to find out the reasons, the author creates goal, emotion, fee, location and habit as the five matching factors which result in those changes. The matching factors are the bridge between the theories and the case study. After generalizing how those factors affect people while using cell phones, future work is to raise up some thoughts of how cell phones will be like in the future which is relevant to how to adapt information technology to human lives.

La thèse concerne le rôle joué par le contexte dans l'accès au Web de données depuis les dispositifs mobiles. Le travail analyse ce problème de deux points de vue distincts: adapter au contexte la présentation de triplets, et protéger l'accès aux bases des données RDF depuis les dispositifs mobiles. La première contribution est PRISSMA, un moteur de rendu RDF qui étend Fresnel avec la sélection de la meilleure représentation pour le contexte physique où on se trouve. Cette opération est effectuée par un algorithme de recherche de sous-graphes tolérant aux erreurs basé sur la notion de distance d'édition sur les graphes. L'algorithme considère les différences entre les descriptions de contexte et le contexte détecté par les capteurs, supporte des dimensions de contexte hétérogènes et est exécuté sur le client pour ne pas révéler des informations privées. La deuxième contribution concerne le système de contrôle d'accès Shi3ld. Shi3ld supporte tous les triple stores et il ne nécessite pas de les modifier. Il utilise exclusivement les langages du Web sémantique, et il n'ajoute pas des nouveaux langages de définition de règles d'accès, y compris des analyseurs syntaxiques et des procédures de validation. Shi3ld offre une protection jusqu'au niveau des triplets. La thèse décrit les modèles, algorithmes et prototypes de PRISSMA et de Shi3ld. Des expériences montrent la validité des résultats de PRISSMA ainsi que les performances au niveau de mémoire et de temps de réponse. Le module de contrôle d'accès Shi3ld a été testé avec différents triple stores, avec et sans moteur SPARQL. Les résultats montrent l'impact sur le temps de réponse et démontrent la faisabilité de l'approche. / This thesis discusses the influence of mobile context awareness in accessing the Web of Data from handheld devices. The work dissects this issue into two research questions: how to enable context-aware adaptation for Linked Data consumption, and how to protect access to RDF stores from context-aware devices. The thesis contribution to this first research question is PRISSMA, an RDF rendering engine that extends Fresnel with a context-aware selecting of the best presentation according to mobile context. This operation is performed by an error-tolerant subgraph matching algorithm based on the notion of graph edit distance. The algorithm takes into account the discrepancies between context descriptions and the sensed context, supports heterogeneous context dimensions, and runs on the client-side - to avoid disclosing sensitive context information. The second research activity presented in the thesis is the Shi3ld access control framework for Linked Data servers. Shi3ld has the advantage of being a pluggable filter for generic triple stores, with no need to modify the endpoint itself. It adopts exclusively Semantic Web languages and it does not add new policy definition languages, parsers nor validation procedures. Shi3ld provides protection up to triple level. The thesis describes both PRISSMA and Shi3ld prototypes. Test campaigns show the validity of PRISSMA results, along with memory and response time performance. The Shi3ld access control module has been tested on different triple stores, with and without SPARQL engines. Results show the impact on response time, and demonstrate the feasibility of the approach.

Under senare år har smartphones växt till att bli det mest populära sättet att besöka internet. I takt med detta har även väntande online blivit mer påverkat av externa faktorer kopplat till användarkontexten, exempelvis visuella och auditiva distraktioner. I studien utforskar vi nödvändiga designval vars syfte är att anpassa designen efter en allt mer varierande omgivning och påverkande distraktioner med avseende i en minskad upplevd väntetid för användaren. Vi utforskar och utvärderar olika sätt att designa med syftet att minska användarens upplevda väntetid och därmed bidra till en mer positiv helhetsupplevelse under smartphoneanvändandet. Studiens bidrag landar i tre designförslag till hur laddare kan designas för en bättre upplevd väntetid i en mobil användarkontext med externa distraktioner i åtanke. / The recent years have seen smartphone use grow to become the most popular way to access the web. With this, waiting online has also become increasingly affected by surrounding factors connected to context, for example through visual and auditory distractions. In the study, we explore necessary design-choices in order to adapt the design to the increasingly varied surroundings and distractions in a smartphone environment and to reduce the user(s) perceived waiting time. We explore and evaluate ways to design with the purpose to shorten the user(s) perceived waiting time and therefore lead to a more positive user experience during smartphone use. The study’s contribution results in three design suggestions for how loaders can be designed for a better perceived waiting time within a mobile user context with external distractions in mind. / <p>Tilldelad pris för bästa kandidatuppsats inom informatik vid Högskolan i Halmstad år 2020.</p>