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Nicolini, Andrea. "Context-Aware Computing e Tecnologie Wearable." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10556/.
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Quest' ultimo ventennio ha visto una vera e propria rivoluzione dei dispositivi, partendo dal computer desktop, passando ai laptop fino ad arrivare agli smartphone. Oggi giorno invece si parla di computer indossabili, i dispositivi stanno diventando sempre più piccoli e integrati in oggetti di moda come possono essere degli orologi, occhiali e orecchini.Questi sono connessi in rete con migliaia di dispositivi e con computer più grandi, con i quali, gli utenti nel corso della giornata interagiscono continuamente senza nemmeno rendersene conto scambiandosi migliaia di piccole informazioni: quando si cammina per strada, in centro città quando si fanno compere, quando si è in casa a guardare la TV. Questo ha portato quindi alla nascita di una nuova tipologia di sistemi, in risposta ai cambiamenti portati da questa rivoluzione, i così detti "Sistemi Context-Aware".Il context di un utente può essere descritto come la relazione che vi è tra i suoi dispositivi elettronici, e l' ambiente che lo circonda, a seconda di dove si trova esso dovrà dare delle risposte opportune, e compiere quindi autonomamente certe azioni, tal volta ad insaputa dell' utente. Le applicazioni che usano quindi questo sistema, vengono continuamente messe a conoscenza dei cambiamenti che vengono apportati all' ambiente circostante, regolandosi e reagendo di conseguenza in autonomia. Ad esempio, il nostro dispositivo scopre tramite la rete, la presenza di un amico nelle vicinanze, mentre stiamo passeggiano per strada, allora potrebbe inviarci un messaggio mostrandoci chi è, e dove si trova, con il tragitto da percorrere per raggiungerlo.
Le migliaia di informazioni che vengono quindi scambiate in rete andranno a creare “un ambiente intelligente”, con il quale gli utenti interagiscono inviando informazioni sul proprio conto, senza nemmeno accorgersene, in modo da avere una risposta personalizzata, da parte dell' ambiente.
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Ergüt, Salih. "Context-aware computing for wireless networks." Diss., [La Jolla] : University of California, San Diego, 2010. http://wwwlib.umi.com/cr/ucsd/fullcit?p3402341.
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Thesis (Ph. D.)--University of California, San Diego, 2010.Title from first page of PDF file (viewed May 14, 2010). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Hübinette, Daniel. "Occupancy Sensor System : For Context-aware Computing." Thesis, KTH, Kommunikationssystem, CoS, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91936.
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This masters thesis project, "Occupancy Sensor System", was conducted at Kungliga Tekniska Högskolan (KTH), Stockholm, Sweden, during the period 2007-04-24 – 2007-12-17. The goal of the project was to design an occupancy sensor system that determines if there exists more than one person in a defined region. The output of this system is for use in a context-aware system at the KTH Center for Wireless Systems (Wireless@KTH). The system is important because there is a need for specific input to context-aware systems concerning occupancy of spaces and because this thesis has focused on a problem that enables new complex and interesting services. Additionally, the specific problem of determining not only occupancy, but if this occupancy is zero, one, many has not been widely examined previously. The significance of zero occupants indicating an empty room has already been recognized as having economic and environmental value in terms of heating, ventilating, air-conditioning, and lighting. However, there has not been an effort to differentiate between a person being alone or if more than one person is present. A context-aware system might be able to use this later information to infer that a meeting is taking place in a meeting room, a class taking place in a classroom or that an individual is alone in a conference room, class room, etc. Thus enabling context-aware services to change their behavior based upon the differences in these situations. An occupancy sensor system prototype was designed to monitor a boundary by using a thermal detector, gumstix computer, an analog to digital converter prototype board, laptop computer, and a context broker. The testing and evaluation of the system, proved it to be sound. However, there are still further improvements and tests to be made. These improvements include: dynamic configuration of the system, communication between the different system entities, detection algorithms, and code improvements. Tests measuring accuracy of a detection algorithm and determining optimal detector placement need to be performed. The next step is to design applications that use the context information provided from the occupancy sensor system and expand the system to use multiple detectors.Examensarbetet "Occupancy Sensor System" genomfördes på Kungliga Tekniska Högskolan (KTH), Stockholm, Sverige, under perioden 2007-04-24 – 2007-12-17. Målet med examensarbetet var att designa ett sensorsystem, som avgör om ett rum är befolkat med fler än en person i ett definierat område. Resultatet av detta system är till för användning i ett kontextmedvetet system som finns i KTH Center for Wireless Systems (Wireless@KTH). Systemet är viktigt eftersom det finns ett behov för specifik input till kontextmedvetna system som berör befolkning av rum och eftersom detta examensarbete har fokuserat på ett problem som möjliggör nya komplexa och intressanta tjänster. Dessutom har det inte tidigare undersökts i vidare bemärkelse hur man kan avgöra om ett rum befolkats av noll, en eller flera personer. Betydelsen av att ett rum är obefolkat har redan ansetts ha ekonomiskt och miljöbetingat värde vad gäller uppvärming, ventilation, luftkonditionering och belysning. Däremot har det inte gjorts ansträngningar att differentiera mellan att en ensam person eller flera är närvarande. Ett kontextmedvetet system skulle kunna använda den senare nämnda informationen för att dra slutsatsen att ett möte pågår i ett mötesrum, en lektion är igång i ett klassrum o.s.v. Detta möjliggör i sin tur för kontextmedvetna tjänster att ändra på sina beteenden baserat på skillnaderna i dessa situationer. En prototyp utvecklades för att övervaka en gräns genom användningen av en termisk detektor, gumstixdator, analog till digital signalkonverterare, bärbar dator och en context broker (kontextförmedlare). Testningar och utvärderingar av systemet visade att systemet var dugligt. Flera förbättringar och tester behöver dock göras i framtiden. Dessa förbättringar inkluderar: dynamisk konfiguration av systemet, kommunikation mellan de olika systementiteterna, detektionsalgoritmer och kodförbättringar. Återstående tester inkluderar mätning av en detektionsalgoritms tillförlitlighet samt optimal placering av detektorer. Nästa steg är att utveckla applikationer som använder kontextinformationen från systemet samt att utveckla systemet till att kunna använda flera detektorer.
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Vieira, André Fonseca dos Santos Dias. "Context-aware personalization environment for mobile computing." Master's thesis, Faculdade de Ciências e Tecnologia, 2012. http://hdl.handle.net/10362/8649.
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Dissertação para obtenção do Grau de Mestre em
Engenharia InformáticaCurrently, we live in a world where the amount of on-line information vastly outstrips any individual’s capability to survey it. Filtering that information in order to obtain only useful and interesting information is a solution to this problem. The mobile computing area proposes to integrate computation in users’ daily activities in an unobtrusive way, in order to guarantee an improvement in their experience and quality of life. Furthermore, it is crucial to develop smaller and more intelligent devices to achieve this area’s goals, such as mobility and energy savings. This computing area reinforces the necessity to filter information towards personalization due to its humancentred paradigm. In order to attend to this personalization necessity, it is desired to have a solution that is able to learn the users preferences and needs, resulting in the generation of profiles that represent each style of interaction between a user and an application’s resources(e.g. buttons and menus). Those profiles can be obtained by using machine learning algorithms that use data derived from the user interaction with the application, combined with context data and explicit user preferences. This work proposes an environment with a generic context-aware personalization model and a machine learning module. It is provided the possibility to personalize an application, based on user profiles obtained from data, collected from implicit and explicit user interaction. Using a provided personalization API (Application Programming Interface) and other configuration modules, the environment was tested on LEY (Less energy Empowers You), a persuasive mobile-based serious game to help people understand domestic energy usage.
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Alharthi, Raneem. "Context–Aware Stress Prediction System." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34486.
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Stress is now recognized as one of the major causes of physical and psychological illness. It is known as a reaction to surrounding environmental threats and the best way to manage it is to understand its triggers. Although people continuously react to their surrounding environments, they sometimes are not aware that certain elements in their environment are considered to be stressors.
Based on this fact, researchers have recently proposed context-aware stress management systems. Most of the proposed systems use context data to provide real time stress monitoring and visualization, along with intervention techniques. However, these interventions are limited to the second and tertiary stages and very little attention has been given to the primary stage.
In this thesis, we introduce a system called CASP. The system’s objective is to provide stress status predictions based on a user’s current contextual data. Therefore, a detection method is developed using heart rate variability (HRV) as a stress indicator to deliver personalized context-aware stress reports. Based on the predicted status, the system provides users with stress interventions at an early stage in order to help avoid and/or eliminate the occurrence of stress. Our evaluation results show that the CASP system is able to predict the stress status of a user with an averaged accuracy of 78.23% through our limited activity, when compare to a stress status measured using physiological signals. Moreover, it provides prediction models that adapt to the changing nature of both the user’s stress status and the surrounding environment.
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Daruwala, Yohann. "A Constructive Memory Architecture for Context Awareness." Thesis, The University of Sydney, 2008. http://hdl.handle.net/2123/2250.
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Context-aware computing is a mobile computing paradigm in which applications can discover, use, and take advantage of contextual information, such as the location, tasks and preferences of the user, in order to adapt their behaviour in response to changing operating environments and user requirements. A problem that arises is the inability to respond to contextual information that cannot be classified into any known context. Many context-aware applications require all discovered contextual information to exactly match a type of context, otherwise the application will not react responsively. The ability to learn and recall contexts based on the contextual information discovered has not been very well addressed by previous context-aware applications and research. The aim of this thesis is to develop a component middleware technology for mobile computing devices for the discovery and capture of contextual information, using the situated reasoning concept of constructive memory. The research contribution of this thesis lies in developing a modified architecture for context-aware systems, using a constructive memory model as a way to learn and recall contexts from previous experiences and application interactions. Using a constructive memory model, previous experiences can be induced to construct potential contexts, given a small amount of learning and interaction. The learning process is able to map the many variations of contextual information currently discovered by the user with a predicted type of context based on what the application has stored and seen previously. It only requires a small amount of contextual information to predict a context, something common context-aware systems lack, as they require all information before a type of context is assigned. Additionally, some mechanism to reason about the contextual information being discovered from past application interactions will be beneficial to induce contexts for future experiences.
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Daruwala, Yohann. "A Constructive Memory Architecture for Context Awareness." University of Sydney, 2008. http://hdl.handle.net/2123/2250.
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Master of Philosophy (Architecture)Context-aware computing is a mobile computing paradigm in which applications can discover, use, and take advantage of contextual information, such as the location, tasks and preferences of the user, in order to adapt their behaviour in response to changing operating environments and user requirements. A problem that arises is the inability to respond to contextual information that cannot be classified into any known context. Many context-aware applications require all discovered contextual information to exactly match a type of context, otherwise the application will not react responsively. The ability to learn and recall contexts based on the contextual information discovered has not been very well addressed by previous context-aware applications and research. The aim of this thesis is to develop a component middleware technology for mobile computing devices for the discovery and capture of contextual information, using the situated reasoning concept of constructive memory. The research contribution of this thesis lies in developing a modified architecture for context-aware systems, using a constructive memory model as a way to learn and recall contexts from previous experiences and application interactions. Using a constructive memory model, previous experiences can be induced to construct potential contexts, given a small amount of learning and interaction. The learning process is able to map the many variations of contextual information currently discovered by the user with a predicted type of context based on what the application has stored and seen previously. It only requires a small amount of contextual information to predict a context, something common context-aware systems lack, as they require all information before a type of context is assigned. Additionally, some mechanism to reason about the contextual information being discovered from past application interactions will be beneficial to induce contexts for future experiences.
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Simons, Christof. "Context aware applications in mobile distributed systems /." Aachen : Shaker, 2008. http://d-nb.info/987900757/04.
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Drakatos, Stylianos. "Context-aware data caching for mobile computing environments." FIU Digital Commons, 2006. http://digitalcommons.fiu.edu/etd/3082.
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The deployment of wireless communications coupled with the popularity of portable devices has led to significant research in the area of mobile data caching. Prior research has focused on the development of solutions that allow applications to run in wireless environments using proxy based techniques. Most of these approaches are semantic based and do not provide adequate support for representing the context of a user (i.e., the interpreted human intention.). Although the context may be treated implicitly it is still crucial to data management. In order to address this challenge this dissertation focuses on two characteristics: how to predict (i) the future location of the user and (ii) locations of the fetched data where the queried data item has valid answers. Using this approach, more complete information about the dynamics of an application environment is maintained.
The contribution of this dissertation is a novel data caching mechanism for pervasive computing environments that can adapt dynamically to a mobile user's context. In this dissertation, we design and develop a conceptual model and context aware protocols for wireless data caching management. Our replacement policy uses the validity of the data fetched from the server and the neighboring locations to decide
which of the cache entries is less likely to be needed in the future, and therefore a good candidate for eviction when cache space is needed. The context aware driven prefetching algorithm exploits the query context to effectively guide the prefetching process. The query context is defined using a mobile user's movement pattern and requested information context. Numerical results and simulations show that the proposed prefetching and replacement policies significantly outperform conventional ones. Anticipated applications of these solutions include biomedical engineering, telehealth, medical information systems and business.
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Ahmed, Ali Ahmed Ali. "Context-aware access control in ubiquitous computing (CRAAC)." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/contextaware-access-control-in-ubiquitous-computing-craac(1eaa4390-7062-4af5-8aa5-d645d91fa547).html.
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Ubiquitous computing (UbiComp) envisions a new computing environment, where computing devices and related technology are widespread (i.e. everywhere) and services are provided at anytime. The technology is embedded discreetly in the environment to raise users' awareness. UbiComp environments support the proliferation of heterogeneous devices such as embedded computing devices, personal digital assistants (PDAs), wearable computers, mobile phones, laptops, office desktops (PCs), and hardware sensors. These devices may be interconnected by common networks (e.g. wired, wireless), and may have different levels of capabilities (i.e. computational power, storage, power consumption, etc). They are seamlessly integrated and interoperated to provide smart services (i.e. adaptive services). A UbiComp environment provides smart services to users based on the users' and/or system's current contexts. It provides the services to users unobtrusively and in turn the user's interactions with the environment should be as non-intrusive and as transparent as possible. Access to such smart services and devices must be controlled by an effective access control system that adapts its decisions based on the changes in the surrounding contextual information. This thesis aims at designing an adaptive fine-grained access control solution that seamlessly fits into UbiComp environments. The solution should be flexible in supporting the use of different contextual information and efficient, in terms of access delays, in controlling access to resources with divergent levels of sensitivity. The main contribution of this thesis is the proposal of the Context-Risk-Aware Access Control (CRAAC) model. CRAAC achieves fine-grained access control based upon the risk level in the underlying access environment and/or the sensitivity level of the requested resource object. CRAAC makes new contributions to the access control field, those include 1) introducing the concept of level of assurance based access control, 2) providing a method to convert the contextual attributes values into the corresponding level of assurance, 3) Proposing two methods to aggregate the set of level of assurance into one requester level of assurance, 4) supporting four modes of working each suits a different application context and/or access control requirements, 5) a comprehensive access control architecture that supports the CRAAC four modes of working, and 6) an evaluation of the CRAAC performance at runtime.
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Nguyen, Tammy. "Context-aware access control in pervasive computing environments." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Summer2005/t%5Fnguyen%5F061005.pdf.
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Simons, Christof. "Context aware applications in mobile distributed systems." Aachen Shaker, 2007. http://d-nb.info/987900757/04.
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CORREA, MARIANA FERREIRA GOMES. "GOOGLE APP: THE INTERFACE AND COMPUTING INTERACTION CHALLENGES IN CONTEXT-AWARE COMPUTING." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=31159@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
Diversos sistemas e aplicações são capazes de identificar um determinado contexto de uso em tempo real, detectando informações para antecipar situações e otimizar sua interface. Esses sistemas que agem de forma contextual e, muitas das vezes, proativa pertencem à área da Computação ciente de contexto. O aplicativo Google para sistemas Android e IOS possui um serviço de assistente virtual para dispositivos móveis que utiliza dados da conta do usuário obtidos através dos serviços Google, além de dados do próprio dispositivo. O assistente é capaz de identificar hábitos, antever necessidades e oferecer cards de informações antes mesmo que sejam pedidos pelo usuário. Pertencendo ao campo da computação ciente de contexto, o aplicativo Google foi eleito como objeto de estudo e avaliado sob o viés da engenharia semiótica. Através da interface do aplicativo, analisou-se a qualidade da comunicação designer-usuário, tendo por objetivo verificar não apenas a eficiência da assistência virtual oferecida pelo sistema, mas também a autonomia do usuário e a flexibilidade do aplicativo diante de suas necessidades.
Many modern systems and applications are capable of analising the contexts of use in real time, identifying key information to anticipate upcoming actions and optimize their interfaces. Those systems that work in a contextual manner and, usually, in a proactive way, belong to the Context Aware Computing area. The Google App for Android and iOS devices has a virtual assistant service that collects data obtained from different sources associated to the user account and links them to data from the user device. The assistant can identify habits, anticipate probable needs and offer information cards even before the user asks for them. Being part of the Context Aware Computing field, the Google App was elected as study object and was evaluated under the Semiotics Engineering bias. From the application s interface, the quality of the user-designer communication was analysed so, not only the virtual assistant efficiency could be evaluated, but also the user autonomy and the application flexibility according to his needs.
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Brander, William. "A model for adaptive multimodal mobile notification." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/699.
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Information is useless unless it is used whilst still applicable. Having a system that notifies the user of important messages using the most appropriate medium and device will benefit users that rely on time critical information. There are several existing systems and models for mobile notification as well as for adaptive mobile notification using context awareness. Current models and systems are typically designed for a specific set of mobile devices, modes and services. Communication however, can take place in many different modes, across many different devices and may originate from many different sources. The aim of this research was to develop a model for adaptive mobile notification using context awareness. An extensive literature study was performed into existing models for adaptive mobile notification systems using context awareness. The literature study identified several potential models but no way to evaluate and compare the models. A set of requirements to evaluate these models was developed and the models were evaluated against these criteria. The model satisfying the most requirements was adapted so as to satisfy the remaining criteria. The proposed model is extensible in terms of the modes, devices and notification sources supported. The proposed model determines the importance of a message, the appropriate device and mode (or modes) of communication based on the user‘s context, and alerts the user of the message using these modes. A prototype was developed as a proof-of-concept of the proposed model and evaluated by conducting an extensive field study. The field study highlighted the fact that most users did not choose the most suitable mode for the context during their initial subscription to the service. The field study also showed that more research needs to be done on an appropriate filtering mechanism for notifications. Users found that the notifications became intrusive and less useful the longer they used them.
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Ceran, Onur. "A Context Aware Emergency Management System Using Mobile Computing." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615606/index.pdf.
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In this thesis, an emergency management system taking advantage of mobile computing and its awareness on context is provided. The framework primarily aims to create an infrastructure for acquiring implicit and explicit data about an emergency situation by using capabilities of smart mobile devices and converting them into value-added information to be used in phases of emergency management. In addition to conceptual description of the framework, a real prototype implementation is developed and successful application of the framework is demonstrated. Sample cases are analyzed in conjunction with the prototype and an experiment for reporting an emergency situation is carried out by a group of participants in order to demonstrate the applicability and feasibility of the framework. Data collected during the experiment are examined in order to determine the advantages of the proposed system in comparison with traditional emergency reporting efforts.
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Bradley, Nicholas Andrew. "A user-centred design framework for context-aware computing." Thesis, University of Strathclyde, 2005. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21561.
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Many exciting and promising application areas of mobile context-aware computing have emerged in recent years, such as tourist guides and navigation systems for visually impaired people. However, many researchers express grave concerns about the limited appreciation of human and social issues in design: usability issues remain unresolved particularly relating to mobile computer settings, and existing user-centred design approaches/frameworks are still in their infancy. This thesis proposes a framework to advance user-centred approaches to designing context-aware systems in order to help application developers (i) build richer descriptions or scenarios of mobile computer settings, and (ii) identify key human and social issues affecting the usability of their context-aware system. After a critical review of literature, a multidisciplinary model of context was developed in order to bring together theories, and proposed models, of context in Psychology, Linguistics, and Computer Science. This invaluable exercise illustrated the implications those theories have for context-aware computing. Three key perspectives of the multidisciplinary model were then used to investigate the issue of personalisation of context-aware services, focusing mainly on navigation services for visually impaired people. Firstly, the 'user's context' was investigated, where significant differences were found in the use of landmarks to navigate by people with a central vision loss, people with a peripheral vision loss, and registered blind people. Secondly, the 'application's context' involved designing context-aware services for transmission to participants within indoor and outdoor routes. Thirdly, the 'user-application's context', which brought together the first two perspectives, was investigated where it was found that certain groups were more effective at reaching landmarks when being given information that derived from people in the same visual impairment category. The multidisciplinary model, and the studies investigating its three key perspectives, were combined to form a user-centred framework for contextaware design. Key contributions included (i) richer modelling of user-interface interaction in mobile settings, and (ii) an augmentation to existing user-centred design approaches which includes not just meaningful activities of the user but also incidental and unpredictable activities that occur frequently in mobile settings.
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Cheung, Ronnie Chu-ting. "An adaptive modelling infrastructure for context-aware mobile computing." Thesis, London Metropolitan University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.549553.
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Context provides information about the present status of people, places, things, network and devices in the environment. Context-awareness refers to the use of context information for an application to adapt its functionality to the current context of use. Development of context-aware applications is inherently complex. Previous researches on mobile computing emphasize on programmable interfaces for development of context-aware systems. There are limited researches that emphasize on the modelling aspects of adaptive applications. This research aims at developing a complete infrastructure for development of context-aware applications. The infrastructure consists of a middleware for context-aware application development that is supported by a set of context information modelling and reasoning facilities. It aims at extending the capabilities of context-aware middleware infrastructures by incorporating novel approaches to model context and situations under uncertainty. This thesis addresses the key challenges in context-aware computing by a complete infrastructure that aims at achieving the following: (1) support for fuzzy composition of high level context abstraction from low level detector context, and fuzzy-based inference mechanisms, (2) support for mobile services that can be dynamically composed and migrated with reference to adaptation requirements for different context situations, (3) support for modelling of adaptation components and entities.
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Xu, Chang. "Inconsistency detection and resolution for context-aware pervasive computing /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CSED%202008%20XU.
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Lima, Christopher Viana. "Context-aware framework for collaborative applications." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15921.
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Doutoramento em Engenharia InformáticaFuture pervasive environments will take into consideration not only individual user’s interest, but also social relationships. In this way, pervasive communities can lead the user to participate beyond traditional pervasive spaces, enabling the cooperation among groups and taking into account not only individual interests, but also the collective and social context. Social applications in CSCW (Computer Supported Cooperative Work) field represent new challenges and possibilities in terms of use of social context information for adaptability in pervasive environments. In particular, the research describes the approach in the design and development of a context.aware framework for collaborative applications (CAFCA), utilizing user’s context social information for proactive adaptations in pervasive environments. In order to validate the proposed framework an evaluation was conducted with a group of users based on enterprise scenario. The analysis enabled to verify the impact of the framework in terms of functionality and efficiency in real-world conditions. The main contribution of this thesis was to provide a context-aware framework to support collaborative applications in pervasive environments. The research focused on providing an innovative socio-technical approach to exploit collaboration in pervasive communities. Finally, the main results reside in social matching capabilities for session formation, communication and coordinations of groupware for collaborative activities.
O futuro dos ambientes pervasivos irá levar em consideração não só os interesses individuais dos utilizadores, mas também as relações sociais. Desta forma, a participação em comunidades pode levar o utilizador para além da experiência em espaços tradicionais pervasivos, permitindo a cooperação entre grupos e tendo em conta não só os intresses individuais, mas também o contexto coletivo e social. Aplicações sociais na área de CSCW (Computer Supported Cooperative Work) representam novos desafios e possibilidades em termos do uso da informação social de contexto para a adaptação e personalização em computação pervasiva. Esta tese explora o potencial da utilização consciente do contexto e das informações sociais em aplicações CSCW, a fim de apoiar a colaboração em ambientes pervasivos. Em particular, a investigação descreve a abordagem do design e desenvolvimento de um framework consciente do contexto para aplicações colaborativas (CAFCA), utilizando-se das informações de contexto e sociais dos utilizadores para adaptações proactivas em ambientes pervasivos. A fim de validar o framework proposto, uma avaliação foi realizada com um grupo de utilizadores, com base num cenário empresarial. A análise permitiu verificar o impacto do framework em termos de funcionalidade e eficiência em condições do mundo real. A principal contribuição deste trabalho foi desenvolver um framework contexto-aware para suportar aplicações de colaboração em ambientes pervasivos. A investigação centrou-se em uma abordagem sociotécnica inovadora de explorar a colaboração em comunidades. Os principais objetivos residem na capacidade social para formação de sessões, a comunicação e coordenação de groupware para atividades colaborativas.
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Lu, Heng. "A software testing framework for context-aware applications in pervasive computing." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41758067.
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Siu, Po-lam Pauline. "Context-aware state management for supporting mobility in a pervasive environment." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B3147858X.
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Li, Herman Hon Yu. "The Impress Context Store: A Coordination Framework for Context-Aware Systems." Thesis, University of Waterloo, 2006. http://hdl.handle.net/10012/1091.
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The dream of weaving technology into our everyday fabric of life is recently being made possible by advances in ubiquitous computing and sensor technologies. Countless sensors of various sizes have made their way into everyday commercial applications. Many projects aim to explore new ways to utilize these new technologies to aid and interact with the general population. Context-aware systems use available context information to assist users automatically, without explicit user input. By inferring user intent and configuring the system proactively for each user, context-aware systems are an integral part of achieving user-friendly ubiquitous computing environments. A common issue with building a distributed context-aware system is the need to develop a supporting infrastructure providing features such as storage, distributed messaging, and security, before the real work on processing context information can be done. This thesis proposes a coordination framework that provides an effective common foundation for context-aware systems. The separation between the context-processing logic component and the underlying supporting foundation allows researchers to focus their energy at the context-processing part of the system, instead of spending their time re-inventing the supporting infrastructure.
As part of an ongoing project, Impress, the framework uses the open standard, Jabber, as its communication protocol. The Publish-Subscribe (pubsub) extension to Jabber provides interesting features that match those needed by a context-aware system. The main contribution of this thesis is the design and implementation of a coordination framework, called the Impress Context Store, that provides an effective common foundation for context-aware systems. The separation between the context-processing logic and the underlying supporting foundation allows researchers to focus their energy at the context-processing part of the system, instead of spending their time re-inventing the supporting infrastructure.
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Phithakkitnukoon, Santi Dantu Ram. "Inferring social and internal context using a mobile phone." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/ark:/67531/metadc12183.
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Kocaballi, Ahmet Baki. "Weighted Granular Best Matching Algorithm For Context-aware Computing Systems." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605825/index.pdf.
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Weighted granular best matching algorithm is proposed for the operation of context matching in context-aware computing systems. New algorithm deals with the subjective, fuzzy and multidimensional characteristics of contextual information by using weights and a granular structure for contextual information. The proposal is applied on a case: CAPRA &ndashContext-Aware Personal Reminder Agent tool to show the applicability of the new context matching algorithm. The obtained outputs showed that proposed algorithm produces the results which are more sensitive to the user&rsquo
s intention, more adaptive to the characteristics of the contextual information and applicable to a current Context-aware system.
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Project, ULAN. "A Context-aware Course Management System under Ubiquitous Computing Environment." INTELLIGENT MEDIA INTEGRATION NAGOYA UNIVERSITY / COE, 2005. http://hdl.handle.net/2237/10364.
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Jonsson, Martin. "Sensing and Making Sense : Designing Middleware for Context Aware Computing." Doctoral thesis, Stockholm : Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4432.
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Dargie, Waltenegus. "A Distributed Architecture for Computing Context in Mobile Devices." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1151308912028-83795.
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Context-aware computing aims at making mobile devices sensitive to the social and physical settings in which they are used. A necessary requirement to achieve this goal is to enable those devices to establish a shared understanding of the desired settings. Establishing a shared understanding entails the need to manipulate sensed data in order to capture a real world situation wholly, conceptually, and meaningfully. Quite often, however, the data acquired from sensors can be inexact, incomplete, and/or uncertain. Inexact sensing arises mostly due to the inherent limitation of sensors to capture a real world phenomenon precisely. Incompleteness is caused by the absence of a mechanism to capture certain real-world aspects; and uncertainty stems from the lack of knowledge about the reliability of the sensing sources, such as their sensing range, accuracy, and resolution. The thesis identifies a set of criteria for a context-aware system to capture dynamic real-world situations. On the basis of these criteria, a distributed architecture is designed, implemented and tested. The architecture consists of Primitive Context Servers, which abstract the acquisition of primitive contexts from physical sensors; Aggregators, to minimise error caused by inconsistent sensing, and to gather correlated primitive contexts pertaining to a particular entity or situation; a Knowledge Base and an Empirical Ambient Knowledge Component, to model dynamic properties of entities with facts and beliefs; and a Composer, to reason about dynamic real-world situations on the basis of sensed data. Two additional components, namely, the Event Handler and the Rule Organiser, are responsible for dynamically generating context rules by associating decision events ? signifying a user?s activity ? with the context in which those decision events are produced. Context-rules are essential elements with which the behaviour of mobile devices can be controlled and useful services can be provided. Four estimation and recognition schemes, namely, Fuzzy Logic, Hidden Markov Models, Dempster-Schafer Theory of Evidence, and Bayesian Networks, are investigated, and their suitability for the implementation of the components of the architecture of the thesis is studied. Subsequently, fuzzy sets are chosen to model dynamic properties of entities. Dempster-Schafer?s combination theory is chosen for aggregating primitive contexts; and Bayesian Networks are chosen to reason about a higher-level context, which is an abstraction of a real-world situation. A Bayesian Composer is implemented to demonstrate the capability of the architecture in dealing with uncertainty, in revising the belief of the Empirical Ambient Knowledge Component, in dealing with the dynamics of primitive contexts and in dynamically defining contextual states. The Composer could be able to reason about the whereabouts of a person in the absence of any localisation sensor. Thermal, relative humidity, light intensity properties of a place as well as time information were employed to model and reason about a place. Consequently, depending on the variety and reliability of the sensors employed, the Composer could be able to discriminate between rooms, corridors, a building, or an outdoor place with different degrees of uncertainty. The Context-Aware E-Pad (CAEP) application is designed and implemented to demonstrate how applications can employ a higher-level context without the need to directly deal with its composition, and how a context rule can be generated by associating the activities (decision events) of a mobile user with the context in which the decision events are produced.
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Lu, Heng, and 陸恒. "A software testing framework for context-aware applications in pervasive computing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41758067.
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Siu, Po-lam Pauline, and 蕭寶琳. "Context-aware state management for supporting mobility in a pervasive environment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B3147858X.
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Phithakkitnukoon, Santi. "Inferring Social and Internal Context Using a Mobile Phone." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12183/.
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This dissertation is composed of research studies that contribute to three research areas including social context-aware computing, internal context-aware computing, and human behavioral data mining. In social context-aware computing, four studies are conducted. First, mobile phone user calling behavioral patterns are characterized in forms of randomness level where relationships among them are then identified. Next, a study is conducted to investigate the relationship between the calling behavior and organizational groups. Third, a method is presented to quantitatively define mobile social closeness and social groups, which are then used to identify social group sizes and scaling ratio. Last, based on the mobile social grouping framework, the significant role of social ties in communication patterns is revealed. In internal context-aware computing, two studies are conducted where the notions of internal context are intention and situation. For intentional context, the goal is to sense the intention of the user in placing calls. A model is thus presented for predicting future calls envisaged as a call predicted list (CPL), which makes use of call history to build a probabilistic model of calling behavior. As an incoming call predictor, CPL is a list of numbers/contacts that are the most likely to be the callers within the next hour(s), which is useful for scheduling and daily planning. As an outgoing call predictor, CPL is generated as a list of numbers/contacts that are the most likely to be dialed when the user attempts to make an outgoing call (e.g., by flipping open or unlocking the phone). This feature helps save time from having to search through a lengthy phone book. For situational context, a model is presented for sensing the user's situation (e.g., in a library, driving a car, etc.) based on embedded sensors. The sensed context is then used to switch the phone into a suitable alert mode accordingly (e.g., vibrate mode while in a library, handsfree mode while driving, etc.). Inferring (social and internal) context introduces a challenging research problem in human behavioral data mining. Context is determined by the current state of mind (internal), relationship (social), and surroundings (physical). Thus, the current state of context is important and can be derived from the recent behavior and pattern. In data mining research area, therefore, two frameworks are developed for detecting recent patterns, where one is a model-driven approach and the other is a data-driven approach.
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Bauer, Christine, and Alexander Novotny. "A Consolidated View of Context for Intelligent Systems." IOS Press, 2017. http://dx.doi.org/10.3233/AIS-170445.
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This paper's main objective is to consolidate the knowledge on context in the realm of intelligent systems, systems that are aware of their context and can adapt their behavior accordingly. We provide an overview and analysis of 36 context models that are heterogeneous and scattered throughout multiple fields of research. In our analysis, we identify five shared context categories: social context, location, time, physical context, and user context. In addition, we compare the context models with the context elements considered in the discourse on intelligent systems and find that the models do not properly represent the identified set of 3,741 unique context elements. As a result, we propose a consolidation of the findings from the 36 context models and the 3,741 unique context elements. The analysis reveals that there is a long tail of context categories that are considered only sporadically in context models. However, particularly these context elements in the long tail may be necessary for improving intelligent systems' context awareness.
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Al-Sammarraie, Mohammed. "Policy-based approach for context-aware systems." Thesis, De Montfort University, 2011. http://hdl.handle.net/2086/5386.
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Pervasive (ubiquitous) computing is a new paradigm where the computers are submerged into the background of the everyday life. One important aspect of pervasive systems is context-awareness. Context-aware systems are those that can adapt their behaviours according to the current context. Context-aware applications are being integrated into our everyday activity aspects such as: health care, smart homes and transportations. There exist a wide range of context-aware applications such as: mobile phones, learning systems, smart vehicles. Some context-aware systems are critical since the consequence of failing to identify a given context may be catastrophic. For example, an auto-pilot system is a critical context-aware system; it senses the humidity, clouds, wind speed and accordingly adjusts the altitude, throttle and other parameters. Being a critical context-aware system has to be provably correct. Policy-based approaches has been used in many applications but not in context-aware systems. In this research, we want to discover the anatomy (i.e. architecture, structure and operational behaviour) of policy-based management as applied to context-aware systems, and how policies are managed within such a dynamic system. We propose a novel computational model and its formalisation is presented using the Calculus of Context-aware Ambients (CCA). CCA has been proposed as a suitable mathematical notation to model mobile and context-aware systems. We decided to use CCA due to three reasons: (i) in CCA, mobility and context-awareness are primitive constructs and are treated as first-class citizens; (ii) properties of a system can be formally analysed; (iii) CCA specifications are executable, and thus, leading to rapid prototyping and early validation of the system properties. We, then show how policies can be expressed in CCA. For illustration, the specification of the event-condition-action (ECA) conceptual policy model is modelled in CCA in a natural fashion. We also propose a policy-based architecture for context-aware systems, showing its different components, and how they interact. Furthermore, we give the specification of the policy enforcement mechanism used in our proposed architecture in CCA. To evaluate our approach, a real-world case study of an infostation-based mobile learning (mLearning) system is chosen. This mLearning system is deployed across a university campus to enable mobile users to access mobile services (mServices) represented by course materials (lectures, tests and tutorials) and communication services (intelligent message notification and VoIP). Users can access the mServices through their mobile devices (Hand-set phones, PDAs and laptops) regardless of their device type or location within a university campus. We have specified the mLearning system in CCA (i.e. specification based on policies of the mServices), afterwards, the specification is simulated using the CCA interpreter tool. We have developed an animation tool specially designed for the mLearning system. The animation tool provides graphical representation of the CCA processes. In terms of safety and liveness, some important properties of the mLearning system have been validated as a proof of concept.
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deFreitas, Adrian A. "A Framework to Support Opportunistic Groups in Context-Aware Applications." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/849.
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Context-aware computing utilizes information about users and/or their environments in order to provide relevant information and services. To date, however, most context-aware applications only take advantage of contexts that can either be produced on the device they are running on, or on external devices that are known beforehand. While there are many application domains where sharing context is useful and/or necessary, creating these applications is currently difficult because there is no easy way for devices to share information without 1) explicitly directing them to do so, or 2) through some form of advanced user coordination (e.g., sharing credentials and/or IP addresses, installing and running the same software). This makes these techniques useful when the need to share context is known a priori, but impractical for the one time, opportunistic encounters which make up the majority of users’ lives. To address this problem, this thesis presents the Group Context Framework (GCF), a software framework that allows devices to form groups and share context with minimal prior coordination. GCF lets devices openly discover and request context from each other. The framework then lets devices intelligently and autonomously forms opportunistic groups and work together without requiring either the application developer or the user to know of these devices beforehand. GCF supports use cases where devices only need to share information once or spontaneously. Additionally, the framework provides standardized mechanisms for applications to collect, store, and share context. This lets devices form groups and work together, even when they are performing logically separate tasks (i.e., running different applications). Through the development of GCF, this thesis identifies the conceptual and software abstractions needed to support opportunistic groups in context-aware applications. As part of our design process, we looked at current contextsharing applications, systems, and frameworks, and developed a conceptual model that identifies the most common conditions that cause users/devices to form a group. We then created a framework that supports grouping across this entire model. Through the creation of four prototype systems, we show how the ability to form opportunistic groups of devices can increase users and devices’ access to timely information and services. Finally, we had 20 developers evaluate GCF, and verified that the framework supports a wide range of existing and novel use cases. Collectively, this thesis demonstrates the utility of opportunistic groups in context-aware computing, and highlights the critical challenges that need to be addressed to make opportunistic context sharing both practical and usable in real-world settings. The contributions of this thesis are: 1. A conceptual model, based on an analysis of prior literature, which describes the conditions under which users and/or devices form and work in groups. 2. An implementation of the Group Context Framework, which highlights the software abstractions and architecture needed to support all of the group types identified in our conceptual model. 3. A demonstration of the value of opportunistic groups in context aware computing, through the creation of four major systems and numerous smaller applications. 4. A validation of GCF’s robustness, through an examination of 65 ideas submitted by 20 developers. 5. An examination of the challenges associated with utilizing opportunistic groups in context-aware applications, based on our own experiences using GCF, as well as from issues raised by developers from academia and industry.
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Peker, Serhat. "A Novel User Activity Prediction Model For Context Aware Computing Systems." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613662/index.pdf.
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In the last decade, with the extensive use of mobile electronic and wireless communication devices, there is a growing need for context aware applications and many pervasive computing applications have become integral parts of our daily lives. Context aware recommender systems are one of the popular ones in this area. Such systems surround the users and integrate with the environmenthence, they are aware of the users'
context and use that information to deliver personalized recommendations about everyday tasks. In this manner, predicting user&rsquo
s next activity preferences with high accuracy improves the personalized service quality of context aware recommender systems and naturally provides user satisfaction. Predicting activities of people is useful and the studies on this issue in ubiquitous environment are considerably insufficient. Thus, this thesis proposes an activity prediction model to forecast a user&rsquo
s next activity preference using past preferences of the user in certain contexts and current contexts of user in ubiquitous environment. The proposed model presents a new approach for activity prediction by taking advantage of ontology. A prototype application is implemented to demonstrate the applicability of this proposed model and the obtained outputs of a sample case on this application revealed that the proposed model can reasonably predict the next activities of the users.
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Al-Sultany, Ghaidaa Abdalhussein Billal. "Automatic message annotation and semantic interface for context aware mobile computing." Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/6564.
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In this thesis, the concept of mobile messaging awareness has been investigated by designing and implementing a framework which is able to annotate the short text messages with context ontology for semantic reasoning inference and classification purposes. The annotated metadata of text message keywords are identified and annotated with concepts, entities and knowledge that drawn from ontology without the need of learning process and the proposed framework supports semantic reasoning based messages awareness for categorization purposes. The first stage of the research is developing the framework of facilitating mobile communication with short text annotated messages (SAMS), which facilitates annotating short text message with part of speech tags augmented with an internal and external metadata. In the SAMS framework the annotation process is carried out automatically at the time of composing a message. The obtained metadata is collected from the device’s file system and the message header information which is then accumulated with the message’s tagged keywords to form an XML file, simultaneously. The significance of annotation process is to assist the proposed framework during the search and retrieval processes to identify the tagged keywords and The Semantic Web Technologies are utilised to improve the reasoning mechanism. Later, the proposed framework is further improved “Contextual Ontology based Short Text Messages reasoning (SOIM)”. SOIM further enhances the search capabilities of SAMS by adopting short text message annotation and semantic reasoning capabilities with domain ontology as Domain ontology is modeled into set of ontological knowledge modules that capture features of contextual entities and features of particular event or situation. Fundamentally, the framework SOIM relies on the hierarchical semantic distance to compute an approximated match degree of new set of relevant keywords to their corresponding abstract class in the domain ontology. Adopting contextual ontology leverages the framework performance to enhance the text comprehension and message categorization. Fuzzy Sets and Rough Sets theory have been integrated with SOIM to improve the inference capabilities and system efficiency. Since SOIM is based on the degree of similarity to choose the matched pattern to the message, the issue of choosing the best-retrieved pattern has arisen during the stage of decision-making. Fuzzy reasoning classifier based rules that adopt the Fuzzy Set theory for decision making have been applied on top of SOIM framework in order to increase the accuracy of the classification process with clearer decision. The issue of uncertainty in the system has been addressed by utilising the Rough Sets theory, in which the irrelevant and indecisive properties which affect the framework efficiency negatively have been ignored during the matching process.
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Costa, Cristiano Andre da. "Continuum : a context-aware service-based software infrastucture for ubiquitous computing." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/14964.
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Este trabalho apresenta uma proposta de infra-estrutura de software sensível ao contexto para a computação ubíqua (ubicomp) denominada Continuum. A área de ubicomp, também chamada de computação pervasiva, pressupõe uma forte integração com o mundo real, com foco no usuário e na manutenção de alta transparência. Para o desenvolvimento de aplicativos nesse cenário, é necessária uma infra-estrutura de software adequada. A infra-estrutura projetada é baseada no padrão da arquitetura orientada a serviços (service-oriented architecture ou SOA), fazendo uso de framework e middleware, e empregando uma redefinição da semântica siga-me. Nessa visão redefinida, os usuários podem ir para qualquer lugar carregando os dados e os aplicativos que desejam, os quais podem ser usados de forma imperceptível e integrada com o mundo real (seamless integration). O foco particular desse trabalho é sensibilidade ao contexto: a percepção de características relacionadas aos usuários e ao entorno. No trabalho são considerados os recursos disponíveis no ambiente e é mantida a história dos dados de contexto. Além disso, é proposta a representação do contexto para promover raciocínio e compartilhamento de conhecimento, empregando uma ontologia. Dessa forma, contexto é representado de uma maneira formal e bastante expressiva, diferente de muitas soluções existentes hoje em dia que ainda usam modelos de representação ad hoc. Esta tese está então na interseção destas três áreas principais: infra-estrutura de software para ubicomp, sensibilidade ao contexto e ontologias. No desenvolvimento desta tese, também examina-se o campo da computação ubíqua, e sugere-se um modelo de arquitetura geral que enfrente esses desafios fundamentais. Baseado nos requisitos estabelecidos para esse modelo, propõe-se um conjunto de serviços para o Continuum. Os serviços são projetados considerando o trabalho previamente desenvolvido pelo nosso grupo de pesquisa, mais especificamente o projeto ISAM, e particularmente o middleware EXEHDA. A proposta estende esses projetos, adicionando aspectos que não haviam sido considerados no momento do seu desenvolvimento. Particularmente, o suporte a sensibilidade de contexto é melhorado com a proposta de uma ontologia para a formalização da informação de contexto. Algumas análises, usando a metodologia de estudo de caso, foram conduzidas para apreciar as principais proposições da tese. Baseado nessas avaliações, foram apresentadas algumas lições aprendidas e traçada a conclusão do trabalho. Como resultado, Continuum é uma infra-estrutura de software que endereça muitos aspectos da computação ubíqua, integrando imperceptivelmente diferentes desafios.The present work is a proposal of a context-aware software infrastructure for ubiquitous computing (ubicomp) named Continuum. The ubicomp area, also called pervasive computing, presupposes a strong integration with the real world, with focus on the user and on keeping high transparency. For the development of applications in this scenario, we need an adequate software infrastructure. The infrastructure designed in this work is based on service-oriented architecture (SOA), making use of framework and middleware, and employing a redefinition of follow-me semantics. In this redefined vision, users can go anywhere carrying the data and application they want, which they can use in a seamlessly integrated fashion with the real world. The specific focus of our work is context awareness: the perception of characteristics related to users and surroundings. We consider the resources available in the environment and keep a history of context data. Furthermore, we propose the representation of context to promote reasoning and knowledge sharing, using ontology. In this way, context is represented in a considerably expressive, formal approach, different from many solutions that exist today, which still use ad hoc representations models. Our work is then at the intersection of these three main areas: software infrastructures for ubicomp, context awareness, and ontologies. In the development of this thesis, we also survey the field of ubiquitous computing, suggesting a general architectural model to deal with its fundamental challenges. Based on the established requirements for this model, we propose a set of services for Continuum. The services are designed considering the previous works developed by our research group, namely ISAM (Infra-estrutura de Suporte às Aplicações Móveis – Mobile Applications Support Infrastructure), and particularly the middleware EXEHDA (Execution Environment for Highly Distributed Applications). We further extend these projects, by adding aspects to them that had not been considered at the time of their development. Particularly, we improve context awareness support, proposing an ontology for the formalization of context information. We have conducted some analysis, using case study methodology, to evaluate the main propositions of our work. Based on these assessments, we present lessons learned and draw the conclusion of our work. As a result, Continuum is a software infrastructure that addresses many aspects of ubiquitous computing, seamlessly integrating many different challenges.
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Baloch, Raheel Ali. "Context dependency analysis in ubiquitous computing." Phd thesis, Institut National des Télécommunications, 2012. http://tel.archives-ouvertes.fr/tel-00714129.
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To provide users with personalized adaptive services only using the accessible computing resources in a cloud environment, context aware applications need to assimilate both the accessed and derived context, i.e. a combination of more than one sensed data and information in the environment. Context data dependency, dependency that arises between the context data producer and consumer, may get introduced in a system due to numerous reasons. But as the number of context dependencies for a service increases, the more complex the system becomes to manage. The thesis addresses issues of how to identify context dependencies, represent such context dependencies and then reduce them in a system. In the first part of the thesis, we present two efficient approaches to determine context dependency relations among various services in ubiquitous computing environment to help better analyse the pervasive services. One approach is based on graph theory, and we have used the topological sort to determine the context dependencies. The second approach is based on solving constraint networks which determines whether an entity is affected when the state of a certain other entity has its state changed, i.e. determining the dynamic nature of context dependency. In the second part of the thesis, we present a mode for representation of context dependencies within a system. Our model that represents context dependencies is based on set theory and first-order predicate logic. The context dependency representation model also represents alternative sources for context acquisition that can be utilized in a case in which the preferred context producers are not available to service the desired context to the relevant context consumer any more. Further, we try to reduce the context dependencies by presenting the idea of profile context, which is based on the proposal of an open framework for context acquisition, management and distribution. This heuristic approach is based on the idea of utilizing mobile nodes in an ad hoc overlay network with more resources than the context producer itself to store various contextual information under the banner of profile context, and further, provide profile context instead of each context individually based on the queries the nodes receive from the context consumers. Bringing together the context information and context updates from various sources, support for context aware decisions can be implemented efficiently in a mobile environment by addressing the issues of context dependency using profile context
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Dey, Anind K. "Providing architectural support for building context-aware applications." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/9232.
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Zimmermann, Andreas [Verfasser]. "Context Management and Personalisation : A Tool Suite for Context- and User-Aware Computing / Andreas Zimmermann." Aachen : Shaker, 2007. http://d-nb.info/1164341197/34.
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Ntawanga, Felix Fred. "A context-aware model to improve usability of information presented on mobile devices." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1020768.
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Online information access on mobile devices is increasing as a result of the growth in the use of Internet-enabled handheld (or pocket-size) devices. The combined influence of recent enabling technologies such as Web 2.0, mobile app stores and improved wireless networks have driven the increase in online applications that allow users to access various types of information on mobile devices regardless of time and location. Examples of such applications (usually shortened to app) include: social media, such as FacebookTM App and TwitterTM App, banking applications such as (Standard Bank South Africa)TM Mobile Banking App and First National Bank (FNB) BankingTM App, and news application such as news 24TM App and BBCTM News App. Online businesses involved in buying, selling and business transaction processing activities via the Internet have exploited the opportunity to extend electronic commerce (e-commerce) initiatives into mobile commerce (m-commerce). Online businesses that interact with end user customers implement business to consumer (B2C) m-commerce applications that enable customers to access and browse product catalogue information on mobile devices, anytime, anywhere. Customers accessing electronic product catalogue information on a mobile device face a number of challenges such as a long list of products presented on a small screen and a longer information download time. These challenges mainly originate from the limiting and dynamic nature of the mobile apps operating environment, for example, dynamic location, bandwidth fluctuations and, diverse and limited device features, collectively referred to as context. The goal of this research was to design and implement a context-aware model that can be incorporated into an m-commerce application in order to improve the presentation of product catalogue information on m-commerce storefronts. The motivation for selecting product catalogue is prompted by literature which indicates that improved presentation of information in m-commerce (and e-commerce) applications has a positive impact on usability of the websites. Usable m-commerce (and e-commerce) websites improve efficiency in consumer behaviour that impacts sales, profits and business growth. The context-aware model aimed at collecting context information within the user environment and utilising it to determine optimal retrieval and presentation of product catalogue in m-commerce. An integrated logical context sensor and Mathematical algorithms were implemented in the context-aware model. The integrated logical context sensor was responsible for the collection of different types of predetermined context information such as device specification or capabilities, connection bandwidth, location and time of the day as well as the user profile. The algorithms transformed the collected context information into usable formats and enabled optimal retrieval and presentation of product catalogue data on a specific mobile device. Open-source implementation tools were utilised to implement components of the model including: HTML5, PhP, JavaScript and MySQL database. The context-aware model was incorporated into an existing m-commerce application. Two user evaluation studies were conducted during the course of the research. The first evaluation was to evaluate the accuracy of information collected by the context sensor component of the model. This survey was conducted with a sample of 30 users from different countries across the world. In-between the context sensor and main evaluation surveys, a pilot study was conducted with a sample of 19 users with great experience in mobile application development and use from SAP Next Business and Technology, Africa. Finally an overall user evaluation study was conducted with a sample of 30 users from a remote area called Kgautswane in Limpopo Province, South Africa. The results obtained indicate that the context-aware model was able to determine accurate context information in real-time and effectively determine how much product information should be retrieved and how the information should be presented on a mobile device interface. Two main contributions emerged from the research, first the research contributed to the field of mobile Human Computer Interaction. During the research, techniques of evaluating and improving usability of mobile applications were demonstrated. Secondly, the research made a significant contribution to the upcoming field of context-aware computing. The research brought clarity with regard to context-aware computing which is lacking in existing, current research despite the field’s proven impact of improving usability of applications. Researchers can utilise contributions made in this research to develop further techniques and usable context-aware solutions.
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Xu, Tao. "The context-aware middleware in ambient intelligence." Phd thesis, Ecole Centrale de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-01001647.
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Almost 20 years ago, Marc Weiser envisioned the prospect of computer in 21st century, and proposed the pioneering notion of ubiquitous computing. One of Weiser's primary ideas has recently evolved to a more general paradigm known as context awareness, becoming a central research theme in many other ubiquitous computing programs. From Active Badge considered as the first context-aware application, there are numerous attempts to build effective context-aware systems. However, how to acquire context, how to process context and how to create context-aware applications is still faced with enormous challenges in the both of research and practice. This dissertation investigates deeply some chosen key issues in context awareness and develops a context-aware middleware. The main research contributions are presented in three categories: a spatialtemporal context represent model, a context-aware middleware and an intelligence context inference engine. The spatial-temporal context representation model is proposed to organize context and relations for context-aware system. Ontology-based method is adopted to construct our model, supporting both knowledge sharing and reuse as well as logic inference. This model adopts two-layer hierarchy structure for different situation. The higher layer comes up with the generic common context, while the lower layer focuses on various specific situations. Differing from existing models, besides taking locational factors into account, it supports different historical context service depending on different context resource. These context histories may be used to predict and infer the context. A context-aware middleware is designed as a platform associated with context retrieval and context processing. It is organized in two layers: the low layer provides a solution to integrate sensors and actuators with a standardized data representation; the high layer: versatile context interpreter focuses on context processing, which is made up of four parts: Context Aggregator, Inference Engine, Context Knowledge Base, and Query Engine in charge of context inferences, expressive query, and persistent storage. This middleware provides an environment for rapid prototyping of context aware services in ambient intelligent. The intelligent inference engine is the central and intellectual component of context-aware middleware. We review all the methods on activity context recognition published in three premier conferences in past decade and conclude that activity context recognition is divided into three facets: basic activity inference, dynamic activity analysis and future activity recommendation. Then we propose an intelligent inference engine based on our context-aware middleware. Beside satisfying requirements of checking the context consistency, our inference engine integrates the three most popular methods on activity context recognition: Rules, Decision Tree, and Hide Markov Model. It provides a solution for all facets of activity context recognition based on our context-aware middleware. The individuals' information collecting from their social networks under permission are leveraged to train intelligent inference engine. We finally use two scenarios (applications) to explain the generic process to develop application via our middleware, and compare and analyze the main aspects of our middleware with other five representative context-aware applications. Our middleware profits good features from existing context-aware systems and improve intelligence via supporting activity context recognition. It provides an efficient platform for a rapid developing of new context-aware applications in ambient intelligence.
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Chatfield, Craig Andrew. "Privacy and Security in Ubiquitous Computing: Service Delivery and Identity in Intelligent Environments." Thesis, Griffith University, 2010. http://hdl.handle.net/10072/367314.
Full textAbstract:
Ubiquitous computing describes computing technologies that are designed to
be embedded in tools and in our environment, providing computational
support for user interaction and service delivery. Intelligent environments are
context-aware computing environments that deliver services using ubiquitous
computing technologies. These environments provide users with services
tailored to the users’ preferences and the current state of the environment.
The development and implementation of these environments is challenging
due to their potential ability to gather information on the environment’s
occupants and context. The information collection, when combined with
advanced data-mining techniques, has unprecedented potential to invade
users’ privacy. The invasion of privacy is a significant concern to users, and
must be addressed before intelligent environments can gain widespread
acceptance.
The use of ubiquitous computing technologies also poses unique challenges
for service delivery and network security. By definition, ubiquitous computing
describes computing that has faded into the background, allowing users to
use the services and technologies as easily as they would more tangible
physical objects. This integration into our world raises the question that if a
service is inconspicuous enough to blend into the background, how can we
allow users to identify previously unused services? Information security within
intelligent environments is complicated by the physical availability of much of
the environment’s hardware (which leaves it vulnerable to being tampered
with). These privacy and security concerns raise the need for a ubiquitous
computing infrastructure that will allow private interaction and the effective
delivery of personalised and identity-restricted services.
Owing to the large variety of services they could provide, it has been
suggested that intelligent environments will one day cover most of our daily
lives (for example our homes, offices, public transport networks or shopping
centres). This requires a common approach be taken to users’ interaction with
intelligent environments, and suggests a shared infrastructure will be required
to support users’ interactions with different environments. User privacy
requirements necessitate that this infrastructure be independently operated
from the intelligent environments (and its service providers). Further privacy
and interaction requirements highlight the need for user-controlled identity
management structures and anonymous environmental interaction.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Information and Communication Technology
Science, Environment, Engineering and Technology
Full Text
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Hina, Manolo Dulva. "A paradigm of an interaction context-aware pervasive multimodal multimedia computing system." Mémoire, École de technologie supérieure, 2010. http://espace.etsmtl.ca/302/1/HINA_Manolo_Dulva.pdf.
Full textAbstract:
La communication est un aspect très important de la vie humaine ; elle permet aux êtres
humains de se rapprocher les uns avec les autres comme individus et en tant que groupes
indépendants. En informatique, le but même de l'existence de l'ordinateur est la diffusion de
l'information - de pouvoir envoyer et recevoir l'information. Cependant, la capacité
d’échanger de l’information entre humains ne se transfère pas quand l'humain interagit avec
l'ordinateur. Sans intervention externe, les ordinateurs ne comprennent pas notre langue, ne
comprennent pas comment le monde fonctionne et ne peuvent percevoir des informations sur
une situation donnée. Dans une installation typique traditionnelle (souris - clavier - écran)
l'information explicite fournie à l'ordinateur produit un effet contraire à la promesse de
transparence et à la technologie calme ; c’était la vision du calcul omniprésent de Weiser
(Weiser 1991 ; Weiser et Brown 1996). Pour renverser cette tendance, nous devons trouver
les moyens et la méthodologie qui permettent à des ordinateurs d'avoir accès au contexte.
C'est par ce dernier que nous pouvons augmenter la richesse de la communication dans
l'interaction personne-ordinateur, et donc de bénéficier des avantages le plus susceptibles des
services informatiques.
Comme le montre bien la littérature, le contexte est une idée subjective qui évolue dans le
temps. Son interprétation est généralement propre au chercheur. L'acquisition de
l'information contextuelle est essentielle. Cependant, c'est l'utilisateur qui décidera si le
contexte envisagé est correctement capturé/acquis ou pas. La littérature montre que
l'information contextuelle est prédéfinie par quelques chercheurs dès le début – ceci est
correcte si le domaine d'application est fixe. Cette définition devient incorrecte si nous
admettons qu'un utilisateur typique réalise différentes tâches de calcul à différentes
occasions. Dans le but de proposer une conception plus concluante et plus inclusive, nous
pensons que le contenu de l’information contextuelle ne devrait être défini que par
l'utilisateur. Ceci nous mène au concept de l'acquisition incrémental du contexte où des
paramètres de contexte sont ajoutés, modifiés ou supprimés, un paramètre de contexte à la
fois.
Dans ce même ordre d’idée, nous élargissons la notion du contexte au contexte de
l’interaction (CI). Le CI est le terme qui est employé pour se rapporter au contexte collectif
de l'utilisateur (c.-à-d. contexte d'utilisateur), de son milieu de travail (c.-à-d. contexte
d'environnement) et de son système de calcul (c.-à-d. contexte de système). Logiquement et
mathématiquement, chacun de ces éléments de CI - contexte d'utilisateur, contexte
d'environnement et contexte de système - se compose de divers paramètres qui décrivent
l'état de l'utilisateur, de son lieu de travail et de ses ressources informatiques pendant qu'il
entreprend une activité en accomplissant sa tâche de calcul. Chacun de ces paramètres peut
évoluer avec le temps. Par exemple, la localisation de l'utilisateur est un paramètre de
contexte d'utilisateur et sa valeur évoluera selon le déplacement de l'utilisateur. Le niveau de
bruit peut être considéré comme paramètre de contexte d'environnement ; sa valeur évolue
avec le temps. De la même manière, la largeur de bande disponible qui évolue sans
interruption est considérée comme paramètre de contexte de système. Pour réaliser une
définition incrémentale du contexte, nous avons développé un outil appelé machine virtuelle
à couches pour le contexte de l’interaction. Cet outil peut être utilisé pour : a) ajouter,
modifier et supprimer un paramètre de contexte d'une part et b) déterminer le contexte
dépendamment des senseurs (c.-à-d. le contexte est déterminé selon les paramètres dont les
valeurs sont obtenues à partir des données brutes fournies par des senseurs).
Afin de maximiser les bienfaits de la richesse du CI dans la communication personnemachine,
la modalité de l'interaction ne devrait pas être limitée à l'utilisation traditionnelle
souris-clavier-écran. La multimodalité tient compte d'un éventail de modes et de formes de
communication, choisis et adaptés au contexte de l'utilisateur. Dans la communication
multimodale, les faiblesses d'un mode d'interaction sont compensées en le remplaçant par un
autre mode de communication qui est plus appropriée à la situation. Par exemple, quand
l'environnement devient fâcheusement bruyant, l’utilisation de la voix n’est pas appropriée ;
l'utilisateur peut opter pour la transmission de texte ou l'information visuelle. La
multimodalité favorise également l'informatique inclusive comme ceux ayant un handicap
permanent ou provisoire. Par exemple, la multimodalité permet d’utiliser une façon originale
pour présenter des expressions mathématiques aux utilisateurs malvoyants (Awdé 2009).
Avec le calcul mobile, la multimodalité ubiquitaire et adaptative est plus que toujours
susceptible d'enrichir la communication dans l'interaction personne-machine et de fournir les
modes les plus appropriés pour l'entrée / la sortie de données par rapport à l’évolution du CI.
Un regard à la situation actuelle nous informe qu'un grand effort a été déployé en trouvant la
définition du contexte, dans l'acquisition du contexte, dans la diffusion du contexte et
l'exploitation du contexte dans un système qui a un domaine d'application fixe (par exemple
soins de santé, l’éducation, etc.). Par ailleurs, des efforts de recherches sur le calcul
ubiquitaire étaient développés dans divers domaines d'application (par exemple localisation
de l'utilisateur, identification des services et des outils, etc.). Cependant, il ne semble pas y
avoir eu un effort pour rendre la multimodalité ubiquitaire et accessible à diverses situations
de l'utilisateur. À cet égard, nous fournissons un travail de recherche qui comblera le lien
absent. Notre travail – Le paradigme du système multimodal multimédia ubiquitaire sensible
au contexte de l’intéraction – est une conception architecturale qui montre l'adaptabilité à un
contexte beaucoup plus large appelé le contexte d'interaction. Il est intelligent et diffus, c.-àd.
fonctionnel lorsque l'utilisateur est stationnaire, mobile ou sur la route. Il est conçu avec
deux buts à l'esprit. D'abord, étant donné une instance de CI qui évolue avec le temps, notre
système détermine les modalités optimales qui s’adaptent à un tel CI. Par optimal, nous
entendons le choix des modalités appropriées selon le contexte donné de l'interaction, les
dispositifs multimédias disponibles et les préférences de l'utilisateur. Nous avons conçu un
mécanisme (c.-à-d. un paradigme) qui réalise cette tâche. Nous avons également simulé sa
fonctionnalité avec succès. Ce mécanisme utilise l'apprentissage de la machine (Mitchell
1997 ; Alpaydin 2004 ; Hina, Tadj et al. 2006) et un raisonnement à base de cas avec
apprentissage supervisé (Kolodner 1993 ; Lajmi, Ghedira et al. 2007). L’entrée à ce
composant est une instance de CI. Les sorties sont a) la modalité optimale et b) les dispositifs
associés. Ce mécanisme contrôle continuellement le CI de l'utilisateur et s'adapte en
conséquence. Cette adaptation se fait par la reconfiguration dynamique de l'architecture du
système multimodal diffus. En second lieu, étant donné une instance de CI, la tâche et les
préférences de l'utilisateur, nous avons conçu un mécanisme qui permet le choix automatique
des applications de l'utilisateur, les fournisseurs préférés à ces applications et les
configurations préférées de la qualité du service de ces fournisseurs. Ce mécanisme fait sa
tâche en consultation avec les ressources informatiques, percevant les fournisseurs
disponibles et les restrictions possibles de configuration.
Indépendamment des mécanismes mentionnés ci-dessus, nous avons également formulé des
scénarios quant à la façon dont un système doit présenter l'interface utilisateurs étant donné
que nous avons déjà identifié les modalités optimales qui s’adaptent au CI de l'utilisateur.
Nous présentons des configurations possibles d’interfaces unimodales et bimodales fondées
sur le CI donné et les préférences de l'utilisateur.
Notre travail est différent du reste des travaux précédents dans le sens que notre système
capture le CI et modifie son architecture dynamiquement de façon générique pour que
l'utilisateur continue de travailler sur sa tâche n'importe quand n'importe où,
indépendamment du domaine d'application. En effet, le système que nous avons conçu est
généralement générique. Il peut être adapté ou intégré facilement dans divers systèmes de
calcul, dans différents domaines d’applications, avec une intervention minimale. C'est notre
contribution à ce domaine de recherche.
Des simulations et des formulations mathématiques ont été fournies pour soutenir nos idées
et concepts liés à la conception du paradigme. Un programme Java a été développé pour
soutenir notre concept de la machine virtuelle à couches pour le CI incrémental.
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Navarro, Natália de Arruda Botelho. "Spontaneous social network: creating dynamic virtual communities based on context-aware computing." Universidade do Vale do Rio dos Sinos, 2016. http://www.repositorio.jesuita.org.br/handle/UNISINOS/5229.
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Natália de Arruda Botelho Navarro_.pdf: 912556 bytes, checksum: bab9db1d959b92c787ce76766526c617 (MD5)Made available in DSpace on 2016-05-04T13:58:11Z (GMT). No. of bitstreams: 1 Natália de Arruda Botelho Navarro_.pdf: 912556 bytes, checksum: bab9db1d959b92c787ce76766526c617 (MD5) Previous issue date: 2016-03-14
Santander Universidades
Com a emergência de redes sociais junto à difusão mundial de smartphones, ciência de contexto tornou-se um conceito essencial na área da computação móvel. Esforços recentes e pesquisas relevantes sobre redes sociais móveis visam conectar pessoas em ambientes inteligentes, considerando não apenas seu comportamento social, mas também seu contexto. Neste âmbito, este trabalho apresenta um novo modelo de rede social móvel, chamado rede social espontânea. A principal contribuição do modelo de rede social espontânea é possibilitar a criação de comunidades sociais baseadas na combinação de múltiplos contextos, incluindo localização, perfil e dados obtidos de outras redes sociais. Na literatura, encontramos alguns trabalhos que carecem na abordagem de formação de comunidades, no aspecto da limitação a localizações específicas ou em não suportar completamente interações sociais virtuais. Nós desenvolvemos um aplicativo móvel chamado Dino, para proporcionar uma visão do que seria uma aplicação baseada no modelo de rede social espontânea. Para avaliar nosso modelo, realizamos dois experimentos. Primeiro, apresentamos cenários hipotéticos baseados em possíveis aplicações para mensurar a percepção dos usuários quanto ao senso de comunidade. Os cenários descritos foram (1) evento musical (2) evento esportivo (3) shopping center (4) conferência ou workshop (5) escola ou universidade. Em sequência, pedimos que os usuários avaliassem as sugestões de grupos formados pela aplicação, considerando sua relevância em meio aos seus interesses. Então, medimos precisão e recuperação dos grupos sugeridos para cada usuário. Obtemos valores médios de 0.72 e 0.83 para precisão e recuperação, respectivamente. Como resultado dos experimentos para avaliar os cenários propostos, obtemos valores médios de concordância de 84% para senso de comunidade, 80% para senso de pertencimento, 90% para utilidade social, 92% para fidelidade de participação, e 81% para efemeridade das comunidades. Com isso, nossa avaliação retrata que comunidades dinâmicas formadas por uma aplicação baseada no modelo de redes sociais espontâneas poderiam aumentar beneficamente a utilidade de um ambiente virtual social.
With the emerging of online social networks along with the worldwide diffusion of smartphones, context awareness has become an essential concept in the field of mobile computing. Recent efforts and relevant research regarding mobile social networks aim at connecting people in smart environments considering not only their social behavior but also their context. In this perspective, this work presents a novel Mobile Social Network (MSN) model called Spontaneous Social Network (SSN). The main scientific contribution of the SSN model is the possibility of creating social communities based on a combination of multiple contexts, including location, profile and data obtained from external online social networks. In the literature, we found several works that lack on the community grouping approach, on the aspect that they are either limited to a specific location, or do not fully support virtual social interactions. We develop a mobile application called Dino, to provide a glimpse of what an SSN based application would be. To evaluate our model we perform two experiments using the developed mobile client. First, we present hypothetical scenarios based on possible real-world SSN applications to measure users’ perceived sense of community. The scenarios described are (1) music concert (2) sport event (3) shopping mall (4) conference or workshop (5) school or university. Second, we ask users to consider their real interests to assess our formed groups regarding their relevance and measure precision and recall of the groups’ suggestions. We compute average values of 0.72 and 0.83 for precision and recall, respectively. The experiments’ results to assess the proposed scenarios ascertain average values of agreement of 84% for sense of community, 80% for sense of belonging, 90% for social usefulness, 92% for member loyalty, and 81% for communities’ ephemerality. Therefore, our evaluation depict that dynamic virtual communities formed by a SSN model based application would beneficially improve a social-aware virtual environment.
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Al-Jawad, M. M. H. "A context-aware method for verifying user identity in pervasive computing environments." Thesis, University of Salford, 2017. http://usir.salford.ac.uk/43659/.
Full textAbstract:
The necessity of verifying user identity is a crucial element of any system to avoid potential identity attacks. Selecting an appropriate verification method impacts on the system’s overall behaviour since it is a trade-off between security and usability. It is even more significant when that system is situated in a pervasive environment since this type of environment is more vulnerable to such attacks. Any proposed method for this environment needs to be seamless (nonintrusive) and secure. As users in such environments tend to access a variety of resources across multiple networking domains, verifying their identity in a secure way requires a real-time verification method. Therefore, a seamless verification process with a reliable level of security is required. Most existing methods of user identity verification are obtrusive, as they are not devised to work within a pervasive computing environment. This obtrusiveness is particularly germane when the main system uses more than one method in the verification process to enhance system security. Most existing solutions are either unaware of the context of the user, or context-aware but rely on part of the context. The context (current status) of a user can be determined through some primitives such as time and location, which are interpreted in a meaningful user context such as role or privilege. This research proposes a new approach for user identity verification, called Context-Aware Identity Verification (CAIV) which uses multiple context parameters to increase the reliability of the verification process, yet does not rely on obtrusive methods such as biometrics like iris and facial recognition. It uses fuzzy logic reasoning to infer the identity of the user from knowledge about the user’s context. The rules of the fuzzy system were derived by extracting experts’ opinions and casting that knowledge into a fuzzy inference engine. The inference engine makes the system capable of taking decisions in a similar way to that of experienced security personnel. The output of the inference engine is a trust value which reflects how much trust the system has in the claimed identity of the user. Thus, the system interprets the current context of the user into a trust value which eventually enables the system to determine the trustworthiness of the claimed identity. Results obtained from extensive testing of the implemented system on the designated simulator show that the proposed approach as a primary method for user identity verification in pervasive computing environments maintains satisfactory rates in specificity, sensitivity and accuracy. It maintains two aspects: security and seamless access to secured resources in pervasive computing environments. Moreover, the proposed approach guarantees that any compromised user credential information will not threaten the user’s security and privacy in other domains. This kind of threat happens when a user’s credentials are stolen by an intruder, which may give the intruder the ability to use them in other domains. In CAIV situation, these parameters are extracted from contextual information of the system environment; hence, the data breach affects only the CAIV domain without compromising other domains.
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Gui, Feng. "Development of a New Client-Server Architecture for Context Aware Mobile Computing." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/202.
Full textAbstract:
This dissertation studies the context-aware application with its proposed algorithms at client side. The required context-aware infrastructure is discussed in depth to illustrate that such an infrastructure collects the mobile user’s context information, registers service providers, derives mobile user’s current context, distributes user context among context-aware applications, and provides tailored services. The approach proposed tries to strike a balance between the context server and mobile devices. The context acquisition is centralized at the server to ensure the usability of context information among mobile devices, while context reasoning remains at the application level. Hence, a centralized context acquisition and distributed context reasoning are viewed as a better solution overall. The context-aware search application is designed and implemented at the server side. A new algorithm is proposed to take into consideration the user context profiles. By promoting feedback on the dynamics of the system, any prior user selection is now saved for further analysis such that it may contribute to help the results of a subsequent search. On the basis of these developments at the server side, various solutions are consequently provided at the client side. A proxy software-based component is set up for the purpose of data collection. This research endorses the belief that the proxy at the client side should contain the context reasoning component. Implementation of such a component provides credence to this belief in that the context applications are able to derive the user context profiles. Furthermore, a context cache scheme is implemented to manage the cache on the client device in order to minimize processing requirements and other resources (bandwidth, CPU cycle, power). Java and MySQL platforms are used to implement the proposed architecture and to test scenarios derived from user’s daily activities. To meet the practical demands required of a testing environment without the impositions of a heavy cost for establishing such a comprehensive infrastructure, a software simulation using a free Yahoo search API is provided as a means to evaluate the effectiveness of the design approach in a most realistic way. The integration of Yahoo search engine into the context-aware architecture design proves how context aware application can meet user demands for tailored services and products in and around the user’s environment. The test results show that the overall design is highly effective,providing new features and enriching the mobile user’s experience through a broad scope of potential applications.
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Buthpitiya, Senaka. "Modeling Mobile User Behavior for Anomaly Detection." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/362.
Full textAbstract:
As ubiquitous computing (ubicomp) technologies reach maturity, smart phones and context-based services are gaining mainstream popularity. A smart phone accompanies its user throughout (nearly) all aspects of his life, becoming an indispensable assistant the busy user relies on to help navigate his life, using map applications to navigate the physical world, email and instant messaging applications to keep in touch, media player applications to be entertained, etc. As a smart phone is capable of sensing the physical and virtual context of the user with an array of “hard” sensors (e.g., GPS, accelerometer) and “soft” sensors (e.g., email, social network, calendar),it is well-equipped to tailor the assistance it provides to the user. Over the life of a smart phone, it is entrusted with an enormous amount of personal information, everything from context-information sensed by the phone to contact lists to call-logs to passwords. Based on this rich set of information it is possible to model the behavior of the user, and use the models to detect anomalies (i.e., significant variations) in the user’s behavior. Anomaly detection capabilities enable a variety of application domains such as device theft detection, improved authentication mechanisms, impersonation, prevention, physical emergency detection, remote elder-care monitoring, and other proactive services. There has been extensive prior research on anomaly detection in various application domain areas (e.g., fraud detection, intrusion detection). Yet these approaches cannot be used in ubicomp environments as 1) they are very application-specific and not versatile enough to learn complex day to day behavior of users, 2) they work with a very small number of information sources with a relatively uniform stream of information (unlike sensor data from mobile devices), and 3) most approaches require labeled or semi-labeled data about anomalies (in ubicomp environments, it is very costly to create labeled datasets). Existing work in the field of anomaly detection in ubicomp environments is quite sparse. Most of the existing work focuses on using a single sensor information stream (GPS in most cases) to detect anomalies in the user’s behavior. However there exists a somewhat richer vein of prior work in modeling user behavior with the goal of behavior prediction; this is again limited mostly to a single sensor stream or single type of prediction (mostly location). This dissertation presents the notion of modeling mobile user behavior as a collection of models each capturing an aspect of the user’s behavior such as indoor mobility, typing patterns, calling patterns. A novel mechanism is developed for combining these models (i.e.,CobLE), which operate on asynchronous information sources from the mobile device, taking into consider how well each model is estimated to perform in the current context. These ideas are concretely implemented in an extensible framework, McFAD. Evaluations carried out using real-world datasets on this framework in contrast to prior work show that the framework for detecting anomalous behavior, 1) vastly reduces the training data requirement, 2) increases coverage, and 3) dramatically increases performance.
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Ketchum, Devin Kyle. "The Use of the CAfFEINE Framework in a Step-by-Step Assembly Guide." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/96609.
Full textAbstract:
Today's technology is becoming more interactive with voice assistants like Siri. However, interactive systems such as Siri make mistakes. The purpose of this thesis is to explore using affect as an implicit feedback channel so that such mistakes would be easily corrected in real time. The CAfFEINE Framework, which was created by Dr. Saha, is a context-aware affective feedback loop in an intelligent environment. For the research described in this thesis, the focus will be on analyzing a user's physiological response to the service provided by an intelligent environment. To test this feedback loop, an experiment was constructed using an on-screen, step-by-step assembly guide for a Tangram puzzle. To categorize the user's response to the experiment, baseline readings were gathered for a user's stressed and non-stressed state. The Paced Stroop Test and two other baseline tests were conducted to gather these two states. The data gathered in the baseline tests was then used to train a support vector machine to predict the user's response to the Tangram experiment.
During the data analysis phase of the research, the results for the predictions on the Tangram experiment were not as expected. Multiple trials of training data for the support vector machine were explored, but the data gathered throughout this research was not enough to draw proper conclusions. More focus was then given to analyzing the pre-processed data of the baseline tests in an attempt to find a factor or group of factors to determine if the user's physiological responses would be useful to train the Support Vector Machine. There were trends found when comparing the area under the curves of the Paced Stroop Test phasic driver plots. It was found that these comparison factors might be a useful approach for differentiating users based upon their physiological responses during the Paced Stroop Test.Master of Science
The purpose of this thesis was to use the CAfFEINE Framework, proposed by Dr. Saha, in a real-world environment. Dr. Saha's Framework utilizes a user's physical responses, i.e. heart rate, in a smart environment to give information to the smart devices. For example, if Siri were to give a user directions to someone's home and told that user to turn right when the user knew they needed to turn left. That user would have a physical reaction as in their heart rate would increase. If the user were wearing a smart watch, Siri would be able to see the heart rate increase and realize, from past experiences with that user, that the information she gave to the user was incorrect. Then she would be able to correct herself. My research focused on measuring user reaction to a smart service provided in a real-world situation using a Tangram puzzle as a mock version of an industrial assembly situation. The users were asked to follow on-screen instructions to assemble the Tangram puzzle. Their reactions were recorded through a smart watch and analyzed post-experiment. Based on the results of a Paced Stroop Test they took before the experiment, a computer algorithm would predict their stress levels for each service provided by the step-by-step instruction guide. However, the results did not turn out as expected. Therefore, the rest of the research focused more on why the results did not support Dr. Saha's previous Framework results.
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Häkkilä, J. (Jonna). "Usability with context-aware mobile applications:case studies and design guidelines." Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514283236.
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Abstract
Context-awareness, a state where the device is aware of the situation in which it is used, is a technology which has gained an increasing amount of attention in recent years. A context-aware device can infer the use condition, and adapt its behavior according to the circumstances. Mobile handheld devices, which have been highly adopted by large user groups, especially in the form of mobile phones, constitute an interesting platform for context-awareness. They are used in different kinds of situations, where the preferences of users may vary, and where different features are prioritized. While the increasing complexity and growing number of features set challenges to intuitive and easy use of devices, context-awareness may offer solutions to more efficient use of mobile applications and services.
This thesis investigates the interaction issues with context-aware mobile devices. The research has been exploratory including several separate case studies, where interaction and usability matters have been charted. These studies consider topics such as location-awareness, user-defined settings of context-aware applications, and information sharing and privacy. In addition to these case studies, the author has sough to draw a bigger picture on interaction and usability issues with context-aware mobile devices, and incorporated the findings to a more general framework.
Through presenting the case studies it is concluded that context-awareness can improve the usability of mobile devices, but careful design in the application development phase must be emphasized. The usability risks identified through case studies relate to numerous themes, such as diminished user control, increased number of interruptions, information overflow, users' subjective understanding of context attributes and privacy threat. As context-aware technology employs greater risks, e.g. due to the uncertain nature of context recognition, the user-centric design practices and testing in the authentic environment of the context-aware applications should be stressed.
The author proposes design guidelines, which have been developed based on the findings from distinct case studies. The design guidelines aim to offer tangible help to application designers, who may not be acquaint with the special characteristics of context-awareness, and intend to prevent potential usability problems identified through the individual studies. Moreover, an evaluation for the design guidelines and their iteration to the presented form is demonstrated.
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Pather, Direshin. "A model for context awareness for mobile applications using multiple-input sources." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/2969.
Full textAbstract:
Context-aware computing enables mobile applications to discover and benefit from valuable context information, such as user location, time of day and current activity. However, determining the users’ context throughout their daily activities is one of the main challenges of context-aware computing. With the increasing number of built-in mobile sensors and other input sources, existing context models do not effectively handle context information related to personal user context. The objective of this research was to develop an improved context-aware model to support the context awareness needs of mobile applications. An existing context-aware model was selected as the most complete model to use as a basis for the proposed model to support context awareness in mobile applications. The existing context-aware model was modified to address the shortcomings of existing models in dealing with context information related to personal user context. The proposed model supports four different context dimensions, namely Physical, User Activity, Health and User Preferences. A prototype, called CoPro was developed, based on the proposed model, to demonstrate the effectiveness of the model. Several experiments were designed and conducted to determine if CoPro was effective, reliable and capable. CoPro was considered effective as it produced low-level context as well as inferred context. The reliability of the model was confirmed by evaluating CoPro using Quality of Context (QoC) metrics such as Accuracy, Freshness, Certainty and Completeness. CoPro was also found to be capable of dealing with the limitations of the mobile computing platform such as limited processing power. The research determined that the proposed context-aware model can be used to successfully support context awareness in mobile applications. Design recommendations were proposed and future work will involve converting the CoPro prototype into middleware in the form of an API to provide easier access to context awareness support in mobile applications.