Recognition Situations Using Extended Dempster-Shafer Theory

Weiser’s [111] vision of pervasive computing describes a world where technology seamlessly integrates into the environment, automatically responding to peoples’ needs. Underpinning this vision is the ability of systems to automatically track the situation of a person. The task of situation recognition is critical and complex: noisy and unreliable sensor data, dynamic situations, unpredictable human behaviour and changes in the environment all contribute to the complexity. No single recognition technique is suitable in all environments. Factors such as availability of training data, ability to deal with uncertain information and transparency to the user will determine which technique to use in any particular environment. In this thesis, we propose the use of Dempster-Shafer theory as a theoretically sound basis for situation recognition - an approach that can reason with uncertainty, but which does not rely on training data. We use existing operations from Dempster-Shafer theory and create new operations to establish an evidence decision network. The network is used to generate and assess situation beliefs based on processed sensor data for an environment. We also define two specific extensions to Dempster-Shafer theory to enhance the knowledge that can be used for reasoning: 1) temporal knowledge about situation time patterns 2) quality of evidence sources (sensors) into the reasoning process. To validate the feasibility of our approach, this thesis creates evidence decision networks for two real-world data sets: a smart home data set and an officebased data set. We analyse situation recognition accuracy for each of the data sets, using the evidence decision networks with temporal/quality extensions. We also compare the evidence decision networks against two learning techniques: Naïve Bayes and J48 Decision Tree

Ubiquitous Computing

The aim of this book is to give a treatment of the actively developed domain of Ubiquitous computing. Originally proposed by Mark D. Weiser, the concept of Ubiquitous computing enables a real-time global sensing, context-aware informational retrieval, multi-modal interaction with the user and enhanced visualization capabilities. In effect, Ubiquitous computing environments give extremely new and futuristic abilities to look at and interact with our habitat at any time and from anywhere. In that domain, researchers are confronted with many foundational, technological and engineering issues which were not known before. Detailed cross-disciplinary coverage of these issues is really needed today for further progress and widening of application range. This book collects twelve original works of researchers from eleven countries, which are clustered into four sections: Foundations, Security and Privacy, Integration and Middleware, Practical Applications

(Meta)Modeling "Constitutive Communication": Toward a Real-Time Reflexive Infrastructure for Coordination and Codesign

This thesis explores the complex relationship between communication and design practice as they occur within the development of technologies. Contemporary theories of communication and technology provide a conceptual basis for treating communication and design as reflexive structuring acts that change the affordances of an interaction situation while embedded within an environment that constitutes the situation. Drawing upon some of these theories, a design research project is undertaken to define a general infrastructure for real-time interaction that affords users reflexive capabilities for redesigning and restructuring the relational situation from within. The design solution developed here proposes a variety of strategies to model the emergence, complexity, and multiplicity of objects as the negotiated outcomes of situated human-computer interactions. In order to consider the feasibility of this design, an inquiry is performed to assess contemporary approaches to reflexive infrastructure for real-time interaction. Various existing collaboration and coordination frameworks and support environments are examined that articulate solutions to elements of the problem space outlined in this thesis. The analysis focuses on the place-based and activity-based approaches to representing dynamic interaction situations exemplified by the research systems Orbit and Intermezzo. The way that these approaches enable and constrain the development of dynamic interaction situations provides a ground for considering the feasibility of the proposed mechanisms as means for reflexively modeling responsive emergence. The design research project undertaken here results in a more concrete proposal for design of infrastructures that reflexively model complex relationality and support emergent forms of coordination and codesign.</p

More principled design of pervasive computing systems

Pervasive computing systems are interactive systems in the large, whose behaviour must adapt to the user's changing tasks and environment using different interface modalities and devices. Since the system adapts to its changing environment, it is vital that there are close links between the structure of the environment and the corresponding structured behavioural changes. We conjecture that predictability in pervasive computing arises from having a close, structured and easily-grasped relationship between the context and the behavioural change that context engenders. In current systems this relationship is not explicitly articulated but instead exists implicitly in the system's reaction to events. Our aim is to capture the relationship in a way that can be used to both analyse pervasive computing systems and aid their design. Moreover, some applications will have a wide range of behaviours; others will vary less, or more subtly. The point is not so much what a system does as how what it does varies with context. In this paper we address the principles and semantics that underpin truly pervasive systems

More principled design of pervasive computing systems

Pervasive computing systems are interactive systems in the large, whose behaviour must adapt to the user's changing tasks and environment using different interface modalities and devices. Since the system adapts to its changing environment, it is vital that there are close links between the structure of the environment and the corresponding structured behavioural changes. We conjecture that predictability in pervasive computing arises from having a close, structured and easily-grasped relationship between the context and the behavioural change that context engenders. In current systems this relationship is not explicitly articulated but instead exists implicitly in the system's reaction to events. Our aim is to capture the relationship in a way that can be used to both analyse pervasive computing systems and aid their design. Moreover, some applications will have a wide range of behaviours; others will vary less, or more subtly. The point is not so much what a system does as how what it does varies with context. In this paper we address the principles and semantics that underpin truly pervasive systems.</p