This thesis describes research on methods for Ubiquitous/Pervasive Computing to better suit users in an Intelligent Environment. The approach is to create and equip a computing environment, such as our Active Office, with technologies that can identify user needs and meet these need in a timely, efficient and unobtrusive manner.¶ The critical issues in the Intelligent Environment are how to enable transparent, distributed computing to allow continued operation across changing circumstances and how to exploit the changing environment so that it is aware of the context of user location, the collection of nearby people and objects, accessible devices and changes to those objects over time.¶ Since the Intelligent Environment is an environment with rapid and rich computing processing, the distributed context processing architecture (DiCPA) was developed to manage and respond to rapidly changing aggregation of sensor data. This architecture is a scalable distributed context processing architecture that provides: 1. continued operation across changing circumstances for users, 2. the collection of nearby people and objects, 3. accessible devices and 4. the changes to those objects over time in the environment. The DiCPA approach focuses on how the Intelligent Environment provides context information for user location, user mobility and the user activity model. Users are assumed mobile within the Intelligent Environment and can rapidly change their access to relevant information and the availability of communications and computational resources.¶ Context-Aware Computing is a new approach in software engineering for Intelligent Environment. It is an approach in the design and construction of a context-aware application that exploits rapid changes in access to relevant information and the availability of communication and computing resources in the mobile computing environment. The goal of Context-Aware Computing is to make user interaction with the computer easier in the smart environment where technology is spread throughout (pervasive), computers are everywhere at the same time (ubiquitous) and technology is embedded (ambient) in the environment. Context-aware applications need not be difficult, tedious or require the acquisition of new skills on the part of the user. They should be safe, easy, simple to use and should enable new functionality without the need to learn new technology. They should provide relevant information and a simple way for a user to manage.¶ The Intelligent Environment requires a context-aware application to improve its efficiency and to increase productivity and enjoyment for the user. The context awareness mechanism has four fundamental cores i.e. identity (who), activity (what), location (where) and timestamp (when). Based on DiCPA architecture, the model of user location (where), user mobility (where), user activity (what) and Intelligent Environment response (what) were developed. Prototypes were also developed to proof the Context-Aware Computing concept in the Intelligent Environment.¶ An Intelligent Environment uses the multi-disciplinary area of Context-Aware Computing, which combines technology, computer systems, models and reasoning, social aspects, and user support. A “good quality” project for Context-Aware Computing requires core content and provides iterative evaluation processes, which has two types of iteration: design and product iteration of the evaluation. The aim of the development of an evaluation program in Context-Aware Computing is to determine what to test, how to test and the appropriate metrics to use. This work presents the metrics for a good quality project in the Context-Aware Computing area, which is followed by the evaluation of the prototypes of this work.

Researchers have approached the problem of designing context-aware systems, computer systems that can react intelligently to the context in which they are used, from both software engineering and human-centred perspectives. While engineered context-aware systems have found successful application in optimising technical settings without requiring mundane and explicit interaction from humans, challenges remain in furthering their application to more complex environments. In particular, when technical decisions and human actions are intertwined in sophisticated work environments (rather than, for example, the simple act of transferring a mobile phone call to receive a signal from the nearest tower), the problem of designing context-aware systems demands further examination and calls for a new approach. A natural extension of the software engineering approach in more challenging environments is to try to implement increasingly sophisticated algorithms for managing context in the hope that this will lead to autonomous application behaviour. In contrast, research from a human-centred perspective, grounded in the social sciences and philosophy, demonstrates that context is not entirely objective and measurable but rather is dynamic and created through human action. It may not be easily detected through technical sensing systems, and therefore simply employing more sophisticated algorithms within the technical sphere may not be effective. While engineering approaches have continued to evolve, the problem of how to design interfaces to context-aware applications still remains. The research reported in this dissertation investigated the problem of designing context-aware systems for the complex environment of a dental surgery. I undertook, though a participatory design approach (a) to better characterise the problem of designing context-aware systems, and (b) to understand how design methods could be employed to bridge the human and software engineering approaches. The gap in existing research on context-aware systems is evident in the way that the methods applied to designing systems don't provide an insight into how people actively create the context in which they work (in a practical rather than theoretical sense) they don‘t closely examine the behaviours of people, the role and arrangement of artefacts, and the dynamic relationships between people and artefacts. I found that an understanding of how these features of work and human behaviour are realised in practice in a given environment is fundamental to being able to design an effective context-aware system for that environment. The challenge is to design at the boundary between the technical and the social. The contribution of this thesis is an approach that explores context-aware design through synthesis. The synthetic approach leads to design opportunities and guidelines based on an understanding of the processes through which people actively co-create the context in which they work. I have applied and built upon a number of existing user-centred design and participatory design methods, in addition to creating some new methods in order to develop an understanding of how designers can examine the human aspects surrounding the co-creation of context and apply these in a way that progressively informs the design process. The methods collectively represent a novel approach to designing context-aware applications and differ from the more traditional technical approaches of developing software frameworks and infrastructures, and formal models of context, tasks, users, and systems. The techniques presented have focused primarily on developing an understanding of how humans find meaning in their actions along with their interaction with other people and technology. Participatory design methods help participants to reveal potential implicit technical resources that can be presented explicitly in technologies in order to assist humans in managing their interactions with and amidst technical systems gracefully. The methods introduced and the design approach proposed complement existing research on context-awareness from both a human-centred and software engineering perspective. This research builds on the notion of providing resources which allow users to manage their own context and also manage shifts in control while interacting with other people and with a variety of technical artefacts. It does this by examining a complex work environment, in particular looking at the kinds of resources people use and expect to use (and the constraints around these), the form(s) it is appropriate for them to take, and the patterns of interaction they will ultimately be used within.

Ambient intelligence refers to the vision of computationally augmented everyday environments that are sensitive, adaptive and responsive to humans and intelligently support their daily lives. Ambient ecologies are the infrastructures of ambient intelligence. To enable system developers to frame and manage the dynamic and complex interaction of humans with ambient ecologies consisting of a mixture of physical (real) and virtual (digital) objects, novel interaction paradigms are needed. Traditional interaction paradigms like the WIMP (windows, icon, menus, and pointing devices) paradigm for desktop computing operate in a closed world, unaware of the physical, social and cultural context. They restrict human perception and action to screen, mouse and keyboard with the assumption that human attention will be fully devoted to interaction with the computer. Emerging interaction paradigms for ambient intelligence are typically centered on specific devices, specific computing environments or specific human capabilities. Also, many of them are driven by technological advancements rather than viewing the human agent as their starting point. A principled, theoretical approach centered in the individual human agent, their situation and activities that are comprehensive and integrated while at the same time instrumental in the design of ambient ecologies has been lacking. This thesis introduces egocentric interaction as an approach towards the modeling of ambient ecologies with the distinguishing feature of taking the human agent’s body, situation and activities as center of reference, as opposed to the more common device-centric approaches in facilitating human-environment interaction. Egocentric interaction is encapsulated in a number of assumptions and principles such as situatedness, the proximity principle, the physical-virtual equity principle, perception and action instead of “input” and “output,” and activity-centeredness. A situative space model is proposed based on some of these principles. It is intended to capture what a specific human agent can perceive and not perceive, reach and not reach at any given moment in time. The situative space model is for the egocentric interaction paradigm what the virtual desktop is for the WIMP interaction paradigm: more or less everything of interest to a specific human agent is assumed and supposed to happen here. In addition, the conception and implementation of the easy ADL ecology based on egocentric interaction, comprising of smart objects, a personal activity-centric middleware, ambient intelligence applications aimed at everyday activity support, and a human agent literally in the middle of it all is described. The middleware was developed to address important challenges in ambient intelligence: (1) tracking and managing smart objects; (2) tracking a human agent’s situative spaces; (3) recognizing human activities and actions; (4) managing and facilitating human-environment interaction; and (5) to ease up the development of ambient intelligence applications. The easy ADL ecology was first simulated in immersive virtual reality, and then set up physically as a living laboratory to evaluate: (1) the technological and technical performance of individual middleware components, (2) to perform a user experience evaluation assessing various aspects of user satisfaction in relation to the support offered by the easy ADL ecology, and (3) to use it as a research test bed for addressing challenges in ambient intelligence. While it is problematic to directly compare the “proof-of-concept” easy ADL ecology with related research efforts, it is clear from the user experience evaluation that the subjects were positive with the services it offered. / easy ADL project

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.

In this thesis work, a certificate based authentication model supported by mobile devices is provided for ubiquitous computing environments. The model primarily aims to create an infrastructure for controlling and regulating access requests through mobile devices to local resources and services. The model also allows users from different domains to use local resources and services within the scope of agreements between domains. In addition to conceptual description of the model, a real prototype implementation is developed and successful application of the model is demonstrated. Within the prototype implementation, a mobile application is developed for access requests and sensors are used as representative local resources. Sample cases applied on the prototype demonstrate applicability and feasibility of the model.

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

abstract: The ubiquity of embedded computational systems has exploded in recent years impacting everything from hand-held computers and automotive driver assistance to battlefield command and control and autonomous systems. Typical embedded computing systems are characterized by highly resource constrained operating environments. In particular, limited energy resources constrain performance in embedded systems often reliant on independent fuel or battery supplies. Ultimately, mitigating energy consumption without sacrificing performance in these systems is paramount. In this work power/performance optimization emphasizing prevailing data centric applications including video and signal processing is addressed for energy constrained embedded systems. Frameworks are presented which exchange quality of service (QoS) for reduced power consumption enabling power aware energy management. Power aware systems provide users with tools for precisely managing available energy resources in light of user priorities, extending availability when QoS can be sacrificed. Specifically, power aware management tools for next generation bistable electrophoretic displays and the state of the art H.264 video codec are introduced. The multiprocessor system on chip (MPSoC) paradigm is examined in the context of next generation many-core hand-held computing devices. MPSoC architectures promise to breach the power/performance wall prohibiting advancement of complex high performance single core architectures. Several many-core distributed memory MPSoC architectures are commercially available, while the tools necessary to effectively tap their enormous potential remain largely open for discovery. Adaptable scalability in many-core systems is addressed through a scalable high performance multicore H.264 video decoder implemented on the representative Cell Broadband Engine (CBE) architecture. The resulting agile performance scalable system enables efficient adaptive power optimization via decoding-rate driven sleep and voltage/frequency state management. The significant problem of mapping applications onto these architectures is additionally addressed from the perspective of instruction mapping for limited distributed memory architectures with a code overlay generator implemented on the CBE. Finally runtime scheduling and mapping of scalable applications in multitasking environments is addressed through the introduction of a lightweight work partitioning framework targeting streaming applications with low latency and near optimal throughput demonstrated on the CBE. / Dissertation/Thesis / Ph.D. Computer Science 2011

Context awareness means sending the right information to the right user at the righttime. Context is our environment, which can be anything around us such as location,lights, noises etc. To make the context interact with our mobile devices or sensors,there must be protocols for communication and data formats for the “sent” or “received”contextual information so we can give very specific context information tothe user. Since this communication and adaptive part is not well understood, in thispaper we are interested in investigating the technology used for adaptation. We willalso explain how this technology works to adapt itself to changes in the environment.

The purpose of the study is to explore the context, from the users’ perspective, in order to find relevant context parameters that can be useful in the development of the future context-aware technology. The goal is to find some of the context parameters relevant to the situated activity and investigate to what extent and in which way they influence the user in everyday planning activities. The method used in the study was based on scenario descriptions. A total of 41 participants reported how they would have acted in the different situations and they also rated how important they believed the different context factors were in the situations. Analyses were made to reveal relationships between context factors and service properties used by the participants in the scenarios. In the study several interesting relationships between context factors and the use of services were discovered. The level of urgency was in several situations considered to be important, and it was also found to have an impact on how the participants chose to communicate. The cost was introduced by the participants during the study. It seemed to be important; however, in situations with high urgency it became less important. The study revealed a potential relationship between the risk of disturbing the people in the vicinity and the effort to communicate quietly. Another interesting finding was the relationship between privacy and the choice of modality when communicating: voice-based services were avoided. Further, the importance of privacy and disturbance also appeared to have greater influence in non-anonymous situations than in anonymous. / Syftet med studien är att undersöka kontexten, utifrån användarens perspektiv, för att kunna hitta relevanta kontextfaktorer som kan vara användbara i utvecklingen av kontextmedveten teknologi. Målet är att finna kontextfaktorer som är relevanta för den pågående aktiviteten och undersöka i vilken utsträckning och på vilka sätt dessa faktorer påverkar användaren i de dagliga planeringsaktiviteterna. Metoden som användes i studien baserades på scenariobeskrivningar. 41 stycken försöksdeltagare fick beskriva hur de skulle ha handlat i de olika situationerna och de fick också skatta hur viktiga de olika kontextfaktorerena var i situationerna. Analyser genomfördes för att finna samband mellan kontextfaktorer och egenskaper hos de tjänster som försöksdeltagarna använde sig av i scenarierna. I studien upptäcktes en rad intressanta relationer mellan kontextfaktorer och användningen av tjänster. Exempelvis ansågs nivån av brådska vara betydelsefull i flera situationer och den verkade också ha inverkan på hur försöksdeltagarna valde att kommunicera. Försöksdeltagarna introducerade under studien kontextfaktorn kostnad. Kostnaden påverkade valet av tjänster men blev mindre betydande i situationer med stor brådska. Studien visade också på potentiella samband mellan risken att störa människor i sin omgivning och viljan att kommunicera tyst. En annan intressant upptäckt var sambandet mellan avskildhet och kommunikationssätt: röstbaserade tjänster undveks när andra människor fanns i närheten. Dessutom verkade det som om det var viktigare att värna om sin avskildhet och att inte störa andra i ickeanonyma situationer än i situationer där man var helt anonym.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / In clusters and virtualized data centers, the resources must be managed effectively by maximising the SLA fulfilment while minimising the cost. This work proposes a strategy for dynamic resource allocation in virtualized computing environments in order to reduce energy consumption without compromising performance requirements concerning availability and SLA violation. The proposed algorithms, based on classical heuristics, perform virtual machines migration between distinct hosts according to the variation in resources demand. These algorithms were evaluated from measurements in a real environment composed by heterogeneous virtualized hosts. We evaluate their performance in four different scenarios based on the CPU and memory utilization, number of migrations and energy consumption. In general, the results show that the algorithms responsible for consolidation and distribution of virtual machines between hosts are able to reduce energy consumption and dissipate the idle and overload points. / Em clusters e data centers virtualizados, os recursos precisam ser gerenciados com eficÃcia na busca de um trade-off entre a garantia de um atendimento satisfatÃrio à demanda por Qualidade de ServiÃo (QoS) e a reduÃÃo dos custos operacionais por parte dos provedores. Este trabalho propÃe uma estratÃgia para alocaÃÃo dinÃmica de recursos em ambientes computacionais virtualizados com vistas à reduÃÃo do consumo de energia, sem promover sobrecargas que podem comprometer o desempenho dos serviÃos ofertados. Os algoritmos propostos, baseados em heurÃsticas clÃssicas, realizam migraÃÃo de mÃquinas virtuais entre servidores distintos conforme variaÃÃo na demanda por recursos. Estes algoritmos foram verificados e validados por mediÃÃes em um ambiente real composto por servidores virtualizados heterogÃneos. O desempenho da proposta à avaliado em quatro cenÃrios distintos a partir das mÃtricas utilizaÃÃo de CPU, utilizaÃÃo de memÃria, nÃmero de migraÃÃes e consumo de energia. Os resultados mostraram que os algoritmos responsÃveis pela consolidaÃÃo e distribuiÃÃo das mÃquinas virtuais sÃo capazes de reduzir o consumo de energia e dissipar os pontos de Ãcio e sobrecarga do ambiente.