In this thesis, we focused on two problems in mobile application development: contextualization and large-scale testing. We identified the limitations of current contextualization and testing solutions. On one hand, advanced-remote-computing- based mobilization does not provide context awareness to the mobile applications it mobilized, so we presented contextify to provide context awareness to them without rewriting the applications or changing their source code. Evaluation results and user surveys showed that contextify-contextualized applications reduce users' time and effort to complete tasks. On the other hand, current mobile application testing solutions cannot conduct tests at the UI level and in a large-scale manner simultaneously, so we presented and implemented automated cloud computing (ACT) to achieve this goal. Evaluation results showed that ACT can support a large number of users and it is stable, cost-efficiency as well as time-efficiency.

Knowing the semantic category of a robot's current position not only facilitates the robot's navigation, but also greatly improves its ability to serve human needs and to interpret the scene. Visual Place Categorization (VPC) is addressed in this dissertation, which refers to the problem of predicting the semantic category of a place using visual information collected from an autonomous robot platform. Census Transform (CT) histogram and Histogram Intersection Kernel (HIK) based visual codebooks are proposed to represent an image. CT histogram encodes the stable spatial structure of an image that reflects the functionality of a location. It is suitable for categorizing places and has shown better performance than commonly used descriptors such as SIFT or Gist in the VPC task. HIK has been shown to work better than the Euclidean distance in classifying histograms. We extend it in an unsupervised manner to generate visual codebooks for the CT histogram descriptor. HIK codebooks help CT histogram to deal with the huge variations in VPC and improve system accuracy. A computational method is also proposed to generate HIK codebooks in an efficient way. The first significant VPC dataset in home environments is collected and is made publicly available, which is also used to evaluate the VPC system based on the proposed techniques. The VPC system achieves promising results for this challenging problem, especially for important categories such as bedroom, bathroom, and kitchen. The proposed techniques achieved higher accuracies than competing descriptors and visual codebook generation methods.

Location information is used to provide a diverse range of services to users such as emergency, navigation, billing, security, information and advertising services. This information is derived from a broad range of indoor and outdoor technologies. The location information thus derived is of different granularity, different co-ordination system and is controlled by numerous service providers. In addition to this, broad selections of devices are used for providing these services. Having a diverse range of applications requiring location information at different levels of granularity, the need to export location information across multiple devices and the existence of different location determination technologies necessitates the need for heterogeneous location network. These networks derive location information from multiple sources and provides various location-based services to users irrespective of the medium, device or technology used. Security, user privacy and management of location information are some of the important issues that need to be addressed. The main contribution of this thesis is the design of a secure and privacy assured heterogeneous location architecture. A formal methodology was chosen to design the heterogeneous location architecture. The design of the architecture resulted in a novel key distribution protocol and a model for information flow that can be easily encapsulated into applications or architectures having similar requirements. The research also resulted in the enhancement of a proposed location framework for securing critical infrastructures using context-aware self-defending objects. The proposed enhanced framework helps to negate the security vulnerabilities introduced through the use of general-purpose computer systems in critical infrastructures.

Computing is increasingly pervading the activities of our everyday lives: at work, at home, and out on the town. When designing these pervasive systems there is a need to better understand and incorporate the context of use and yet there are limited empirical investigations into what constitutes this context. The user’s physical and social situation is an important part of their context when operating in an urban environment and thus needs to be understood and included in the interaction design of context-aware pervasive computing. This thesis has combined ideas from human computer interaction (HCI) and architecture to investigate indexicality in interface design as an instrument for incorporating physical and social context of the built environment into context-aware pervasive computing. Indexicality in interface design is a new approach to designing HCI for pervasive computing that relies on knowledge of current context to implicitly communicate between system and user. It reduces the amount of information that needs to be explicitly displayed in the interface while maintaining the usefulness and understandability of the communication.

Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Abler, Randal T.; Committee Member: Copeland, John A.; Committee Member: Haas, Kevin; Committee Member: Moore II, Elliot; Committee Member: Owen III, Henry L.

Thesis (Ph.D.)--Computing, Georgia Institute of Technology, 2009. / Committee Chair: Abowd, Gregory; Committee Member: Edwards, Keith; Committee Member: Grinter, Rebecca; Committee Member: LaMarca, Anthony; Committee Member: Starner, Thad.

A Computação Pervasiva tem sido tema de diversos trabalhos nos últimos anos. Essa emergente área de pesquisa propõe uma visão de futuro onde serviços computacionais são oferecidos para os usuários através de inúmeros dispositivos espalhados pelo ambiente. Os serviços são disponibilizados, tanto através da infraestrutura existente dos computadores ligados fisicamente à rede quanto através de dispositivos móveis. Esse espalhamento da computação deve acontecer de maneira natural e imperceptível ao usuário. Dados pessoais, programas e arquivos de dados poderão ser acessados de qualquer lugar em qualquer momento. O poder de processamento será um recurso do ambiente, acessado quando necessário, da mesma forma que é hoje a eletricidade. O usuário não precisará ter ciência de qual máquina realiza o processamento necessário às suas aplicações, contanto que o resultado esperado seja obtido. Acredita-se que essa realidade será atingida através da aliança entre áreas de pesquisa como a Computação em Grade, Computação Móvel e a Computação Consciente do Contexto. A Computação Consciente do Contexto busca enriquecer a comunicação entre os seres humanos e os dispositivos computacionais, tornando sua atuação mais eficaz. As aplicações conscientes do contexto conseguem perceber as modificações que ocorrem no ambiente e adaptar seu comportamento ao novo estado. Esse processo pode ser dividido em três etapas: monitoramento, reconhecimento de contexto e adaptação. Na etapa de monitoramento são coletadas, através de sensores, informações sobre o ambiente. Essas informações, entretanto, são geralmente, de baixo nível de abstração e, portanto, dificilmente usadas diretamente por aplicações. A etapa de reconhecimento de contexto relaciona os dados obtidos do ambiente e transforma-os para que possam ser úteis às aplicações no processo de escolha do comportamento mais adequado à cada circunstância, habilitando a etapa de adaptação a efetivar a transformação do comportamento da aplicação de acordo com a nova situação do ambiente. Este trabalho propõe um servidor de contexto chamado MultiS que tem como objetivo a resolução dos problemas relativos à etapa de reconhecimento de contexto: a produção de dado de contexto baseado em informações de diversos sensores e a capacidade de reagir a modificações no ambiente. Também é proposta uma linguagem para composição de dados do contexto chamada CD-XML utilizada pelas aplicações para descrever ao servidor de contexto os dados aos quais elas são sensíveis. / The Pervasive Computing has been studied on several papers in the last years. This emergent research area presents a vision of future where computational services will be available through uncountable devices scattered across the environment. This service network will be exposed to the users by both traditional wired computers and mobile devices. This distribution of the computing is going to happen smoothly and transparently to the users. Personal data, computer programs, and data files will be available anywhere, anytime. The processing power will be an environment resource and will be accessed whenever needed, in the same way which is the electricity nowadays. The users will no longer need to worry about where their program is being executed, as long as he gets the needed result. The ISAM group believes that this new reality will be achieved through the alliance of research areas such as Grid Computing, Mobile Computing and Context-Aware Computing. The Context-Aware Computing aims to enrich the communication between human being and computer devices. Context-aware applications are capable of recognize the changes on the environment and adapt its own behavior to the new context state. This process can be divided in tree steps: monitoring, context recognition and adaptation. On the monitoring layer, environment information is collected from sensors. Those sensors, however, usually return only low level information, which is hardly used by the applications on its original form. The context recognition layer processes the data acquired from the context and transforms into information aimed to be useful to the adaptation process. With that information the adaptation system can identify the correct behavior for the application on each different context situation. This dissertation propose a context server named MultiS, which target is to solve the problems related to context recognition layer: the production of new context data based on the information of several sensors and the capability of react to changes on the environment. It also presents a new programming language for composition of contextual information, named CD-XML. This language is used by the context-aware applications to communicate to the context server describing which information the application is sensible to.

abstract: As people age, the desire to grow old independently and in place becomes larger and takes greater importance in their lives. Successful aging involves the physical, mental and social well-being of an individual. To enable successful aging of older adults, it is necessary for them to perform both activities of daily living (ADL) and instrumental activities of daily living (IADL). Embedded assessment has made it possible to assess an individual's functional ability in-place, however the success of any technology depends largely on the user than the technology itself. Previous researches in in-situ functional assessment systems have heavily focused on the technology rather than on the user. This dissertation takes a user-centric approach to this problem by trying to identify the design and technical challenges of deploying and using a functional assessment system in the real world. To investigate this line of research, a case study was conducted with 4 older adults in their homes, interviews were conducted with 8 caregivers and a controlled lab experiment was conducted with 8 young healthy adults at ASU, to test the sensors. This methodology provides a significant opportunity to advance the scientific field by expanding the present focus on IADL task performance to an integrated assessment of ADL and IADL task performance. Doing so would not only be more effective in identifying functional decline but could also provide a more comprehensive assessment of individuals' functional abilities with independence and also providing the caregivers with much needed respite. The controlled lab study tested the sensors embedded into daily objects and found them to be reliable, and efficient. Short term exploratory case studies with healthy older adults revealed the challenges associated with design and technical aspects of the current system, while inductive analysis performed on interviews with caregivers helped to generate central themes on which future functional assessment systems need to be designed and built. The key central themes were a) focus on design / user experience, b) consider user's characteristics, personality, behavior and functional ability, c) provide support for independence, and d) adapt to individual user's needs. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2015

A Computação Pervasiva tem sido tema de diversos trabalhos nos últimos anos. Essa emergente área de pesquisa propõe uma visão de futuro onde serviços computacionais são oferecidos para os usuários através de inúmeros dispositivos espalhados pelo ambiente. Os serviços são disponibilizados, tanto através da infraestrutura existente dos computadores ligados fisicamente à rede quanto através de dispositivos móveis. Esse espalhamento da computação deve acontecer de maneira natural e imperceptível ao usuário. Dados pessoais, programas e arquivos de dados poderão ser acessados de qualquer lugar em qualquer momento. O poder de processamento será um recurso do ambiente, acessado quando necessário, da mesma forma que é hoje a eletricidade. O usuário não precisará ter ciência de qual máquina realiza o processamento necessário às suas aplicações, contanto que o resultado esperado seja obtido. Acredita-se que essa realidade será atingida através da aliança entre áreas de pesquisa como a Computação em Grade, Computação Móvel e a Computação Consciente do Contexto. A Computação Consciente do Contexto busca enriquecer a comunicação entre os seres humanos e os dispositivos computacionais, tornando sua atuação mais eficaz. As aplicações conscientes do contexto conseguem perceber as modificações que ocorrem no ambiente e adaptar seu comportamento ao novo estado. Esse processo pode ser dividido em três etapas: monitoramento, reconhecimento de contexto e adaptação. Na etapa de monitoramento são coletadas, através de sensores, informações sobre o ambiente. Essas informações, entretanto, são geralmente, de baixo nível de abstração e, portanto, dificilmente usadas diretamente por aplicações. A etapa de reconhecimento de contexto relaciona os dados obtidos do ambiente e transforma-os para que possam ser úteis às aplicações no processo de escolha do comportamento mais adequado à cada circunstância, habilitando a etapa de adaptação a efetivar a transformação do comportamento da aplicação de acordo com a nova situação do ambiente. Este trabalho propõe um servidor de contexto chamado MultiS que tem como objetivo a resolução dos problemas relativos à etapa de reconhecimento de contexto: a produção de dado de contexto baseado em informações de diversos sensores e a capacidade de reagir a modificações no ambiente. Também é proposta uma linguagem para composição de dados do contexto chamada CD-XML utilizada pelas aplicações para descrever ao servidor de contexto os dados aos quais elas são sensíveis. / The Pervasive Computing has been studied on several papers in the last years. This emergent research area presents a vision of future where computational services will be available through uncountable devices scattered across the environment. This service network will be exposed to the users by both traditional wired computers and mobile devices. This distribution of the computing is going to happen smoothly and transparently to the users. Personal data, computer programs, and data files will be available anywhere, anytime. The processing power will be an environment resource and will be accessed whenever needed, in the same way which is the electricity nowadays. The users will no longer need to worry about where their program is being executed, as long as he gets the needed result. The ISAM group believes that this new reality will be achieved through the alliance of research areas such as Grid Computing, Mobile Computing and Context-Aware Computing. The Context-Aware Computing aims to enrich the communication between human being and computer devices. Context-aware applications are capable of recognize the changes on the environment and adapt its own behavior to the new context state. This process can be divided in tree steps: monitoring, context recognition and adaptation. On the monitoring layer, environment information is collected from sensors. Those sensors, however, usually return only low level information, which is hardly used by the applications on its original form. The context recognition layer processes the data acquired from the context and transforms into information aimed to be useful to the adaptation process. With that information the adaptation system can identify the correct behavior for the application on each different context situation. This dissertation propose a context server named MultiS, which target is to solve the problems related to context recognition layer: the production of new context data based on the information of several sensors and the capability of react to changes on the environment. It also presents a new programming language for composition of contextual information, named CD-XML. This language is used by the context-aware applications to communicate to the context server describing which information the application is sensible to.

A Computação Pervasiva tem sido tema de diversos trabalhos nos últimos anos. Essa emergente área de pesquisa propõe uma visão de futuro onde serviços computacionais são oferecidos para os usuários através de inúmeros dispositivos espalhados pelo ambiente. Os serviços são disponibilizados, tanto através da infraestrutura existente dos computadores ligados fisicamente à rede quanto através de dispositivos móveis. Esse espalhamento da computação deve acontecer de maneira natural e imperceptível ao usuário. Dados pessoais, programas e arquivos de dados poderão ser acessados de qualquer lugar em qualquer momento. O poder de processamento será um recurso do ambiente, acessado quando necessário, da mesma forma que é hoje a eletricidade. O usuário não precisará ter ciência de qual máquina realiza o processamento necessário às suas aplicações, contanto que o resultado esperado seja obtido. Acredita-se que essa realidade será atingida através da aliança entre áreas de pesquisa como a Computação em Grade, Computação Móvel e a Computação Consciente do Contexto. A Computação Consciente do Contexto busca enriquecer a comunicação entre os seres humanos e os dispositivos computacionais, tornando sua atuação mais eficaz. As aplicações conscientes do contexto conseguem perceber as modificações que ocorrem no ambiente e adaptar seu comportamento ao novo estado. Esse processo pode ser dividido em três etapas: monitoramento, reconhecimento de contexto e adaptação. Na etapa de monitoramento são coletadas, através de sensores, informações sobre o ambiente. Essas informações, entretanto, são geralmente, de baixo nível de abstração e, portanto, dificilmente usadas diretamente por aplicações. A etapa de reconhecimento de contexto relaciona os dados obtidos do ambiente e transforma-os para que possam ser úteis às aplicações no processo de escolha do comportamento mais adequado à cada circunstância, habilitando a etapa de adaptação a efetivar a transformação do comportamento da aplicação de acordo com a nova situação do ambiente. Este trabalho propõe um servidor de contexto chamado MultiS que tem como objetivo a resolução dos problemas relativos à etapa de reconhecimento de contexto: a produção de dado de contexto baseado em informações de diversos sensores e a capacidade de reagir a modificações no ambiente. Também é proposta uma linguagem para composição de dados do contexto chamada CD-XML utilizada pelas aplicações para descrever ao servidor de contexto os dados aos quais elas são sensíveis. / The Pervasive Computing has been studied on several papers in the last years. This emergent research area presents a vision of future where computational services will be available through uncountable devices scattered across the environment. This service network will be exposed to the users by both traditional wired computers and mobile devices. This distribution of the computing is going to happen smoothly and transparently to the users. Personal data, computer programs, and data files will be available anywhere, anytime. The processing power will be an environment resource and will be accessed whenever needed, in the same way which is the electricity nowadays. The users will no longer need to worry about where their program is being executed, as long as he gets the needed result. The ISAM group believes that this new reality will be achieved through the alliance of research areas such as Grid Computing, Mobile Computing and Context-Aware Computing. The Context-Aware Computing aims to enrich the communication between human being and computer devices. Context-aware applications are capable of recognize the changes on the environment and adapt its own behavior to the new context state. This process can be divided in tree steps: monitoring, context recognition and adaptation. On the monitoring layer, environment information is collected from sensors. Those sensors, however, usually return only low level information, which is hardly used by the applications on its original form. The context recognition layer processes the data acquired from the context and transforms into information aimed to be useful to the adaptation process. With that information the adaptation system can identify the correct behavior for the application on each different context situation. This dissertation propose a context server named MultiS, which target is to solve the problems related to context recognition layer: the production of new context data based on the information of several sensors and the capability of react to changes on the environment. It also presents a new programming language for composition of contextual information, named CD-XML. This language is used by the context-aware applications to communicate to the context server describing which information the application is sensible to.