[pt] Aplicações para o monitoramento de frotas de veículos e sistemas de logística, coordenação em situações de emergência, monitoramento ambiental ou de gestão de força de trabalho móvel podem usar redes móveis como meio de comunicação, troca de informações e de coordenação entre um número possivelmente grande de nós móveis interligados por uma rede WAN. A maioria desses sistemas requer o monitoramento em tempo real das informações de contexto dos nós móveis, interação com todos os nós participantes, bem como meios de adaptação num cenário muito dinâmico, onde não é possível prever quando, onde e por quanto tempo os nós permanecerão conectados. As soluções atuais ainda não têm recursos essenciais necessários para a comunicação com os nós móveis, tais como a entrega confiável de mensagens, suporte a handover, resistência a conectividade intermitente, mudanças de endereço IP e firewall transversal. Esta tese propõe um modelo de gestão de dados que permite a implantação de uma rede de componentes de provedores de dados com disseminação e transformação rápida e confiável de informações entre milhares de nós móveis interligados através de internet sem fio. Os testes de desempenho indicam que o nosso modelo consegue escalar para milhares de nós móveis e suporta disseminação confiável, rápida e com alta taxa de transferência da informação entre milhares de provedores de contexto e consumidores de contexto móveis. / [en] Applications such as vehicle fleet monitoring and logistic systems, emergency response coordination, environmental monitoring or mobile workforce management, employ mobile networks as means of communication, information sharing and coordination among a possibly very large set of mobile nodes interconnected by a Wide Area Network (WAN). The majority of those systems thus requires real-time tracking of the mobile nodes context information, interaction with all participant nodes, as well as means of adaptability in a very dynamic scenario, where it is not possible to predict when, where and for how long the nodes will remain connected. Despite being a subject of much research, current solutions still lack essential features required for communication with mobile nodes, such as reliable message delivery, handover support, resilience to intermittent connectivity, IP address changes and firewall transversal. This thesis proposes a data management model that enables deployment of a network of Data Provider components with reliable and on-time dissemination and transformation of information among thousands of mobile nodes interconnected through wireless internet. Performance tests indicate that our model scales to thousands of mobile nodes and supports reliable, high throughput and on-time data dissemination between several thousands of mobile Data Providers and Data Consumers.

Abstract The popularity of social networking services emphasises the importance of user communities. As the next evolutionary step, social networking will evolve towards user communities that are dynamically established according to contextual aspects such as the shared location and/or activities of people. In this vision, distributed peer-to-peer (P2P) technologies provide a respectable alternative to the centralised client-server technologies for implementing the upcoming community-centric mobile services. This thesis focuses on the development of enabling techniques and methods for a community-centric mobile service environment and on the evaluation of users’ perceptions and user acceptance of novel community-centric mobile services. The research was carried out by first examining the applicability of different P2P system architectures for implementing the management of user communities. Next, an experimental prototype of a community-centric mobile service environment was implemented. The experimental prototype was used for evaluating the performance of the community-centric mobile service environment and for conducting the user studies of novel community-centric mobile services. The evaluation was conducted in a real deployment environment with test users. The main results are the following: (1) a conceptual analysis of the advantages and disadvantages of P2P group management systems that are implemented using architecturally distinct P2P system architectures; (2) a performance evaluation of a P2P community management system, in which each community is implemented as an independent structured P2P overlay network; (3) a novel community-centric mobile service environment and its core component, a mobile middleware, which enables the use of P2P technologies and context information as part of Web-based applications running on a Web browser; (4) an evaluation of users’ perceptions and user acceptance of novel community-centric mobile services that are related to making a selection of an entertainment premise based on its music style and voting for music in a user community. / Tiivistelmä Käyttäjäyhteisöiden tärkeys on korostunut sosiaalista verkottumista edistävien palveluiden suosion kautta. Seuraavaksi sosiaalinen verkottuminen tulee laajentumaan yhteisöihin, jotka perustetaan dynaamisesti muun muassa ihmisten yhteisen sijainnin ja/tai toiminnan perusteella. Tulevaisuuden yhteisöllisten mobiilipalveluiden toteutuksessa hajautetut vertaisverkkoteknologiat tarjoavat varteenotettavan vaihtoehdon keskitetyille asiakas-palvelin -teknologioille. Tämä väitöskirjatyö keskittyy kehittämään tarvittavia tekniikoita ja menetelmiä yhteisöllisen mobiilipalveluympäristön toteuttamiseen sekä arvioimaan käyttäjien kokemuksia uusista yhteisöllisistä mobiilipalveluista. Tutkimuksessa tarkasteltiin aluksi arkkitehtuurillisesti erilaisten vertaisverkkojärjestelmien sopivuutta käyttäjäyhteisöjen hallinnan toteutettamiseksi. Seuraavaksi tutkimuksessa toteutettiin kokeellinen prototyyppi yhteisöllisestä mobiilipalveluympäristöstä. Kokeellista prototyyppiä hyödynnettiin sekä yhteisöllisen mobiilipalveluympäristön suorituskyvyn että uusien yhteisöllisten mobiilipalveluiden käyttäjäkokemuksen arvioinnissa. Arviointi suoritettiin aidossa käyttöympäristössä testikäyttäjien avulla. Väitöskirjatyön keskisimmät tulokset ovat seuraavat: (1) käsitteellinen analyysi arkkitehtuurillisesti erilaisten vertaisverkkojärjestelmien vahvuuksista ja heikkouksista ryhmänhallintajärjestelmän toteuttamisessa; (2) sellaisen yhteisönhallintajärjestelmän arviointi, jossa jokainen yhteisö on toteutettu erillisen ja itsenäisen rakenteellisen vertaisverkon avulla; (3) uusi yhteisöllinen mobiilipalveluympäristö, jonka keskeisin osa mobiili välikerrosohjelmisto mahdollistaa vertaisverkkoteknologioiden ja kontekstitiedon käyttämisen selaimessa toimivissa Web-sovelluksissa; (4) sellaisten uusien yhteisöllisten mobiilipalveluiden käyttäjäkokemuksen arviointi, jotka liittyvät vapaa-ajan viettopaikan valitaan musiikin perusteella ja soitettavan musiikin äänestämiseen käyttäjäyhteisöissä.

The technological advances in wireless networks, smart phones, social networks, embedded sensor technologies and the wide spread of mobile devices have exposed customers to number of services. With these advanced technological innovations, computing capability and connectivity, customers look forward to get useful services and information by means of their mobile devices anywhere and at anytime thereby saving time and money. The importance of mobile commerce is increasing every day, since the mobile devices are becoming central part of our lives. One of the challenge here is the ability to reinforce the application behavior by utilizing context information. The analysis and utilization of context information is necessary to build intelligent applications and thereby focusing on less user attention by understanding the current situation. The information about the current location of a mobile customer, the time of request, and personal characteristics like nature of work, profession and economic status are utilized by applications to provide accurate context-aware services. Many of context-aware applications focus mainly on user activity, preferences which are not sufficient to provide context-aware intelligent services. However, there are few works in developing an integrated model for analyzing the context information. Many authors describe the context representation using five elements like who, what, where, when and how to provide a user centric view without emphasizing on the feature of generality and structural representation of context parameters. Since context information takes multiple forms, it is essential and necessary to make broad classification which helps application designers and developers to deal with possible contexts and their impact on application behavior. In addition, the context classification enables to understand complex customer situations due to changing mobile environment. Therefore, it is required to design a model which analyzes the context information of customers in a dynamic environment and hence, provide real time accurate service. The design and development of context-aware mobile commerce services requires a general conceptual model which can handle any type of context information for different applications. Due to the dynamic nature of business environment and also the customer preferences keep emerging, there is a need to develop business model which adapts to changing environment. To understand the current situation of customers in such highly dynamic environments and to enable the business transactions quickly among parties involved, it is essential to construct and analyze an integrated view of information from distinct sources. The adaptation of the provided services based on customer needs depends when the relevant context information is self-described in the form of beliefs. The observations made on combination of context information are deduced into beliefs as a result the decision making time to provide service reduces considerably. The aim of the thesis, is to design and develop a context-aware system which has been applied for mobile commerce environment by considering the customer context information. To do this, we have designed two models: the Context-Information, Observation and Belief (C-IOB)model and the commercial business model. The main function of C-IOB model is to support the application to identify a suitable context-aware service and to execute business transaction for a customer by analyzing the context information in the form of beliefs. We classify the used Context Information(CI)into four types: physical, system, application and social environment. The business model discusses the formal description of participants who are involved in commercial business. The C-IOB model The Context Information, Observation and Belief model deduces beliefs on customer, by combination of available context information during transaction execution or service provision. The beliefs represent the various situations of customers based on specific nature of the applications. The beliefs developed about an entity(e.g. ,person, place, thing) are primitive in most theories of decision making so that applications can use these beliefs to identify and execute context-aware services. The C-IOB model reduces the solution search space, since the knowledge about an entity is organized using cognitive factors, which maps user context information into real world observations and beliefs, as a result the decision making time by the system reduces considerably. The five CI -constructs: who, what, where, when and how enable many types of context information acquisition in our work. The commercial business model A commercial business model mainly involves the formal description of business participants who are involved in commercial business transactions. To meet the growing needs and to fulfill high expectations of customers, it is very important that application designers have to address the issue of building viable business models for commercial environment. The business model describes how an enterprise or an organization captures and delivers economical value to customers. In particular, the customers play major role in transactions execution and hence understanding and identifying the needs of customer is an important issue in building the business model for commercial purpose. Mobile Commerce Environment Mobile commerce environment (MCE) is one of the specific forms of commercial business model. It deals with transactions like purchases with the objective of supplying commodities like goods and services to customers using mobile devices. A Mobile commerce environment is established by considering set of customers, vendors and bankers, who are involved in commercial business activities like buying of electronic goods and services. The environment is based on certain factors like the type of customers, the type of transactions and the type of electronic products involved in purchasing. M-commerce is one of the most effective and useful ways of conducting business as the customers are constantly using mobile devices and it significantly assists customers in making transactions anywhere, anytime and thereby improving the customer satisfaction. C-IOB model based mobile commerce environment Mobile commerce applications are required to be flexible, in providing services due to inherent anytime and anywhere paradigm. The traditional systems during commercial business transactions, take large time to search the right product, which leads to more utilization of device resources like memory and computational power. In addition, the users are striked with more information which is not significant. Therefore, there is a need to design applications, which identify the customer requirements by acquiring the context information from distinct sources and thereby providing timely and specific information or services to the customer. Hence, to adapt services based on various situations, it is required to develop a systematic approach for representation and utilization of context information modified to special characteristics of mobile commerce applications. The mobile commerce environment uses C-IOB model for analyzing the relevant context information of customers and the context based beliefs helps to identify a suitable service for an end customer, thereby reducing mobile transaction execution time and providing customer benefits. The simulation environment consists of 10,000 electronic products which are categorized based on technical and commercial features. The simulation is carried out with ten mobile commerce transactions, the database consists of information about500 customers and 100vendors who deal with electronic products selling and10bankersfor money transactions. The customer context information is acquired from physical, system, application and social environment. When customers ends are quest for a service, the current context information is acquired, a set of observations is formulated and belief is deduced. The customer is provided with relevant information or service based on deduced belief. The simulation exhaustively tests the working of the system for mobile commerce transactions under different context environments. Some of the case studies are designed by applying the C-IOB model which includes placing the purchase order for the product, money transfer and after sales service. In summary, we have developed a context-aware system by using C-IOB model and also the design of commercial business model. To evaluate the performance of the system, we have incorporated context-awareness aspect for 10 business transactions applied to mobile commerce. The proposed system using C-IOB model provides customer required services as accurately as possible. The system has the capability to adapt to real time situation of customer needs, thereby enhancing the customer satisfaction. The simulation results have shown that the time to execute mobile commerce transactions is less using context based beliefs compared to context unaware approach. The accuracy of the system with belief based approach is higher than without context information. The customer benefits in business transaction are also enhanced by our design approach.

Diversos pesquisadores vêm investigando métodos e técnicas para tornar possível às pessoas anotarem vídeos de modo transparente. A anotação pode ser realizada com a fala, com o uso de tinta digital ou algum outro meio que possa ser capturado enquanto a pessoa assiste ao vídeo. Tais anotações podem ser compartilhadas com outras pessoas, que podem estar assistindo ao mesmo vídeo em um mesmo instante ou em momentos diferentes, sendo interessante ainda que as anotações possam ser realizadas por várias pessoas de modo colaborativo. O paradigma Watch-and-Comment (WaC) propõe a captura transparente de anotações multimodais de usuários enquanto os mesmos assistem e comentam um vídeo. Como resultado desse processo, é gerado um vídeo digital interativo integrando o conteúdo original às anotações realizadas. Esta dissertação tem por objetivo explorar conceitos de computação ubíqua, redes sociais, redes peer-to-peer e TV interativa na proposta de um modelo arquitetural de ciência de informações de contexto para aplicações definidas segundo o paradigma WaC. O modelo explora a integração de um serviço ao paradigma, que auxilie ou forneça alternativas para que aplicações, do momento da captura ao acesso das anotações, utilizem informações de contexto do usuário, do vídeo e das anotações. O modelo também auxilia no estudo de colaboração entre usuários que realizam anotações em vídeos. Outra contribuição da dissertação é a prototipação de aplicações para avaliar e refinar o modelo proposto. São apresentadas extensões para a aplicação WaCTool, considerando o uso de redes sociais e de alternativas para a anotação em vídeos / Researchers have been investigating methods and techniques to allow people to annotate videos ubiquitously. Annotations can be made using voice, digital ink or some other media that can be captured while a person watches a video. These annotations can be shared with other people, who can be watching a video on the same time or at a different one. Also, these annotations can be made by many people collaboratively. The Watch-and-Comment (WaC) paradigm aims at capturing multimodal annotations in an ubiquitous way, while users watch and comment some video. As a result, an interactive digital video is generated combining the original content and the annotations. The work reported on this thesis explores concepts such as ubiquitous computing, social networks, peer-to-peer networks and interactive digital TV, to propose an architectural context-aware model to the applications defined by WaC paradigm. The model proposes the integration of a new service to the paradigm, supporting applications on the annotation process by offering capture alternatives and using context information from user, video and annotations. Also, the model provides a study in collaborative annotation process. Another contribution of this thesis is the prototypes built to evaluate and upgrade the proposed model. The prototypes are extensions from WaCTool, considering the use of social networks and alternatives to annotate in videos

[pt] A computação orientada a contexto (Context-Aware Computing) é um paradigma que se propõe a permitir que as aplicações descubram e tirem proveito das informações que as circundam em dado instante, tais como localização, recursos próximos, infra-estrutura disponível, preferências do usuário, além de outras. Muitas pesquisas realizadas nessa área estão focadas na computação móvel ou na computação ubíqua. Entretanto, mais recentemente, foi possível perceber que há vários aspectos que não estão apenas limitados ao universo da ubiqüidade e da mobilidade e que também podem beneficiar outros sistemas. Os sistemas multimídia/hipermídia mais completos devem apoiar todas as etapas que envolvem o tratamento de um documento, iniciando na sua concepção, abrangendo seu armazenamento e terminando com a apresentação do documento ao leitor (usuário final). Um requisito desejável desse tipo de sistema, em particular, diz respeito à presença de mecanismos que realizem a adaptação do documento, ou seja, que efetuem algum tipo de transformação para tornar o hiperdocumento o mais adequado ao contexto no qual ele estará sendo visualizado. Sistemas hipermídia dotados de estratégias de adaptação constituem um exemplo de aplicação orientada ao contexto. O objetivo desta dissertação é propor uma arquitetura de gerência de contexto, projetada e desenvolvida como uma estrutura independente e reutilizável por diferentes sistemas, em especial, os sistemas hipermídia. A arquitetura propõe um modelo para representação da informação contextual e uma estrutura genérica (framework) capaz de ser reutilizada e incorporada em diversas implementações. / [en] Context Aware Computing is a paradigm that allows applications to find and take profit from information that surrounds them at a given time, such as location, nearby resources, available infra-structure, user preferences, among others. Research in this area focuses on mobile or ubiquitous computing. However, recent research indicates that several aspects of this area are not limited to mobility and ubiquity. They can also profit from systems connected to other areas. Comprehensive multimedia/hypermedia systems must support all the phases of a document treatment. The treatment must encompass authoring, as well as storage and final presentation to the reader (end user). Particularly in this type of system, it is desirable to have tools that adapt the document, that is, tools that apply transformations to the hyper-document, making it adequate to the visualization. Hypermedia systems with adaptation strategies are an example of context-aware applications. The goal of this dissertation is to create a new architecture for context management: one architecture developed and built as an independent structure that may be reused by different systems, particularly by hypermedia systems. This architecture is based on a model of context information representation and on a recyclable framework that can be incorporated to several implementations.

Advances in Internet-of-Things integrate sensors and actuators in everyday items or even people transforming our society at an accelerated pace. This occurs in areas such as agriculture, logistics, transport, healthcare, and smart cities and has created new ways to interact with and experience entertainment, (serious) games, education, etc. Common to these domains is the challenge to realize and maintain complex relations with any object or individual globally, with the requirement for immediacy in maintaining relations of varying complexity. Existing architectures for maintaining relations on the Internet, e.g., DNS and search engines are insufficient in meeting these challenges. Their deficiencies mandate the research presented in this dissertation enabling the maintenance of dynamic and multi-criteria relationships among entities in real-time in an Internet-of-Things while minimizing the overall cost for maintaining such context-centric relationships. A second challenge is the need to represent nearness in context-centric relationships, since solutions need to build on what is closely related. The dissertation shows that the proximity on relations can be used to bring about the scalability of maintaining relationships across the IoT. It successfully demonstrates the concept and feasibility of self-organizing context-centric overlay networks for maintaining scalable and real-time relationships between endpoints co-located with associated physical entities. This is complemented by an object model for annotating objects and their relationships as derived and defined over the underpinning context interactions. Complementing measures of nearness are added through a non-metric multi-criteria approach to evaluating the notion of context proximity. A query language and an extension to the publish-subscribe approaches achieves distributed support for discovering such relationships; locating entities relative to a defined hyper-sphere of interest. Furthermore, it introduces adaptive algorithms for maintaining such relationships at minimal overall costs. The results demonstrate the feasibility of moving towards context-centric approaches to immersion and that such approaches are realizable over vast and distributed heterogeneous collections of user and their associated context information.