This project aims to describe how workflow systems can integrate and make use of context information from context rich environments, to enhance the execution of workflow processes. Context information can for example be used to control transitions between activities, activity enactment and process/activity coordination. A dynamic contextual environment also requires that a workflow system is capable of responding to contextual events. A set of requirements for a context-aware workflow system, based on existing workflow standards, theory behind context-aware computing and activity theory, will be presented and elaborated. Prototypes, which illustrate how these requirements can be implemented in a standard based workflow system, are also provided. Based on the solutions presented in the prototypes, a new interface for a workflow enactment service is presented. This new interface serves as the link between the contextual environment and the workflow system. We also present a solution for handling context related exception states. The definition of basic terms in workflow systems are expanded to better support context-aware behaviour. Ideas and solutions for more complex requirements not met in our prototypes are also discussed, such as situated activity coordination.

Pervasive computing is an important trend today. It concerns devices and services in a smart space that interact with users in a simple, natural, and harmonious way. Many problems in this domain have been studied from different perspectives in various projects. However, one important characteristic of pervasive computing, which is how to make it non-intrusive so that users can focus on their tasks, has received little formal attention. Nowadays, many computing entities including smart devices, and software components, are involved in our daily lives, and users need to deal with them as well as with other people. Besides, people are easy to reach with multiple devices. We believe there should be a systematic way to help users avoid intrusive ones. We propose a model for posing and answering two questions: will an interaction intrude on its receiver if delivered, and given that the interaction is deliverable, how can it be delivered effectively and not too overtly? With this model, the intrusion problem is analyzed and the essential factors are identified. A quantitative approach is used, so that factors have quantitative values for comparison and computation. We also apply context to refine them in order to achieve better results. We then illustrate how to materialize the model and build a system whose design is inspired by the Jabber framework that includes a collection of standards, technologies, and projects for instant messaging. The discussion is at a general level that does not depend on Jabber. However, by choosing Jabber in implementation, we reuse existing software and technologies, and benefit from Jabber/XMPP standardization, its low entry barrier for application developers, and its rich community support. The main contributions of our work are two-fold. First, we propose a model for intrusiveness in pervasive computing. Second, we address the problem at the system level by designing and realizing it. We also make use of standardized instant-messaging technologies, more precisely Jabber, in the system instantiation to reuse existing software, making the system more flexible and extensible.

This paper intends to describe the work and result of the design project Meet App. Meet App lets users interact around their current locations in a direct manner. The user experience is evaluated to get an understanding of the usefulness and interaction with this type of design. The project is related to the context-awareness research field where findings put the project in a greater whole. The result indicates usefulness and enjoyment interacting with the application, but because of the low number of participants the findings cannot be validated.

Pervasive computing is an important trend today. It concerns devices and services in a smart space that interact with users in a simple, natural, and harmonious way. Many problems in this domain have been studied from different perspectives in various projects. However, one important characteristic of pervasive computing, which is how to make it non-intrusive so that users can focus on their tasks, has received little formal attention. Nowadays, many computing entities including smart devices, and software components, are involved in our daily lives, and users need to deal with them as well as with other people. Besides, people are easy to reach with multiple devices. We believe there should be a systematic way to help users avoid intrusive ones. We propose a model for posing and answering two questions: will an interaction intrude on its receiver if delivered, and given that the interaction is deliverable, how can it be delivered effectively and not too overtly? With this model, the intrusion problem is analyzed and the essential factors are identified. A quantitative approach is used, so that factors have quantitative values for comparison and computation. We also apply context to refine them in order to achieve better results. We then illustrate how to materialize the model and build a system whose design is inspired by the Jabber framework that includes a collection of standards, technologies, and projects for instant messaging. The discussion is at a general level that does not depend on Jabber. However, by choosing Jabber in implementation, we reuse existing software and technologies, and benefit from Jabber/XMPP standardization, its low entry barrier for application developers, and its rich community support. The main contributions of our work are two-fold. First, we propose a model for intrusiveness in pervasive computing. Second, we address the problem at the system level by designing and realizing it. We also make use of standardized instant-messaging technologies, more precisely Jabber, in the system instantiation to reuse existing software, making the system more flexible and extensible.

Purpose: The purpose of our work is to develop a system for automatic contact tracing with the goal of identifying individuals who are most likely infected, even if we do not have direct diagnostic information on their health status. Control of the spread of respiratory pathogens (e.g. novel influenza viruses) in the population using vaccination is a challenging problem that requires quick identification of the infectious agent followed by large-scale production and administration of a vaccine. This takes a significant amount of time. A complementary approach to control transmission is contact tracing and quarantining, which are currently applied to sexually transmitted diseases (STDs). For STDs, identifying the contacts that might have led to disease transmission is relatively easy; however, for respiratory pathogens, the contacts that can lead to transmission include a huge number of face-to-face daily social interactions that are impossible to trace manually. Method: We developed a Bayesian network model to process context awareness proximity sensor information together with (possibly incomplete) diagnosis information to track the spread of disease in a population. Our model tracks real-time proximity contacts and can provide public health agencies with the probability of infection for each individual in the model. For testing our algorithm, we used a real-world mobile sensor dataset of 80 individuals, and we simulated an outbreak. Result: We ran several experiments where different sub-populations were ???infected??? and ???diagnosed.??? By using the contact information, our model was able to automatically identify individuals in the population who were likely to be infected even though they were not directly ???diagnosed??? with an illness. Conclusion: Automatic contact tracing for respiratory pathogens is a powerful idea, however we have identified several implementation challenges. The first challenge is scalability: we note that a contact tracing system with a hundred thousand individuals requires a Bayesian model with a billion nodes. Bayesian inference on models of this scale is an open problem and an active area of research. The second challenge is privacy protection: although the test data were collected in an academic setting, deploying any system will require appropriate safeguards for user privacy. Nonetheless, our work illustrates the potential for broader use of contact tracing for modelling and controlling disease transmission.

Mobile applications can benefit from increased awareness of the device's context. Unfortunately, existing solutions for inferring context require special purpose sensors or beacons on the mobile devices or in the physical environment. This requirement significantly limits the deployment of these solutions. In this thesis, I argue that mobile devices can infer a substantial amount of their context by leveraging their existing wireless interfaces to monitor ambient radio sources, such as GSM cell towers or WiFi access points. I focus on two important problems in context-aware computing: localization of mobile devices and detecting proximity between mobile devices for authentication purposes. Specifically, I present an accurate localization system based on fingerprinting of GSM signals. I show that the key to more accurate GSM localization is the use of wide signal strength fingerprints that include readings from a large number of base stations. Next, I present a method that addresses the key drawback of fingerprint-based localization systems - the need to collect extensive measurements to train the system in every target environment. Finally, I show how radio environment sensing can be used to secure the communication of devices that come within close proximity. Removing the need for additional hardware on the mobile devices and in the physical environment renders the approach that I present amenable for widespread deployment.

Context-awareness in pervasive computing environments can reduce user interactions with computing devices by making applications adaptive and autonomous. Context-aware applications rely on information about user context and user preferences to guide their own behaviour. However, context-aware applications do not always behave as users expect due to imperfection of context information, incorrect user preferences or incorrect adaptation rules. This may cause users to feel loss of control over their applications. To mitigate these problems, context-aware systems must provide mechanisms to strike a suitable balance between user control and software autonomy. Allowing users to scrutinise the system and allowing the system to sometimes include users in the adaptation decision making, can provide a balance of user control. This thesis addresses the shortcoming in development of context-aware pervasive systems with regard to providing balance between user control and software autonomy. The thesis shows that rather than making a context-aware application a complete black box, it is possible to allow user control of application adaptations. The system can reveal to the user what context information the system uses and how it arrives at adaptation decisions if the user requests such information. The user may decide to alter the adaptive behaviour of the system to achieve desired outcomes. Hence, a context-aware application becomes a closed loop system where the user is put into the loop if requested. The proposed approach is developed under an assumption that users differ in the level of their technology expertise and therefore the system has to provide explanations that are suitable for a particular level of user expertise. The thesis makes two important research contributions: design of the architectural framework and development of the platform exposing autonomic behaviour of context-aware applications. The architectural framework supports developers of context aware-applications in providing balance of control between users and software autonomy. The framework describes a set of models that allow revealing the adaptation behaviour of context-aware applications in a way suitable for users with various levels of expertise. The framework consists of: (i) a model for exposing elements that influence the context-aware behaviour, (ii) a generic architecture for providing balance of control, (iii) a user model, and (iv) a context graph based overview of context-aware adaptations. The platform exposing autonomic behaviour of context-aware applications is a proof of concept prototype of a software infrastructure (middleware) providing balance of control. The software infrastructure includes: (i) a Semantic Manager, developed to serve the description of elements required for explanations of the application behaviour; (ii) an extension of the PACE Middleware, to enable the middleware to expose the context information, preferences, adaptation rules and their evaluation traces, respectively. (iii) supporting tools for the application designer to prepare the overview of context-aware adaptations and review the evaluation traces. Finally, this thesis presents a case study that illustrates and evaluates the system supporting balance of control. This evaluation involves the existing application which is developed using the previous version of the PACE middleware. The case study validates the architectural framework and illustrates the process and issues involved in developing context-aware application that are able to expose elements that influence context-aware behaviour.

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.

Today almost everyone owns a mobile phone, adults along with teenagers and kids. Even laptops and other wearable devices such as personal digital assistants (PDA’s) are become more common. We want constant connectivity to networks and the Internet, which in turn makes us more and more available. Context-awareness will play a bigger role for these devices in the future. Aware of its surroundings, a portable device can adapt and communicate with different devices and objects, hiding complexity from the user. This enables a simpler user interface and reduces user interaction. This master thesis builds partially upon the prior work done by Maria José Parajón Dominguez. To realize the concept of “context-awareness” HP’s iPAQ Pocket PC h5500 was used together with a server/client application developed as part of this thesis project. Questions that were addressed; what are the effects on the traffic to and from the mobile device of having a personal voice interface; what are the effect on the traffic to and from the mobile device of having significant local storage; and is it possible to exchanging personal CODECs to reduce bandwidth. With this background in mind, this thesis focuses on audio for mobile users in a quest to create more useful devices by exploiting context awareness. / Idag äger nästan alla en mobiltelefon, vuxna, tonåringar så väl som barn. Även bärbara datorer och andra bärbara apparater så som ”personal digital assistans” (PDA:er) blir vanligare. Vi strävar efter konstant dataåtkomst, vilket i sin tur gör oss mer och mer tillgängliga för andra. ”Context-awareness” kommer att spela en större roll för dessa apparater i framtiden. Medveten om sin omgivning, så kan en portabel apparat anpassa sig och kommunicera med andra, utan att göra det komplext för användaren. Detta medför ett enklare gränssnitt för användaren och minskar användarens samspel. Detta examensarbete bygger delvis på ett tidigare arbete av Maria José Parajón Dominguez. För att realisera begreppet “context-awareness” användes HP:s iPAQ Pocket PC h5500 tillsammans med en utvecklad server/klient programvara. Frågor som man försökte besvara var; vilken effekt trafiken har till och från PDA:n vid användning av ett röstgränssnitt; vilken effekt trafiken har till och från PDA:n vid lagring av mycket lokalt utrymme; och om det är möjligt att utväxla personliga algoritmer, så kallade CODECs. Med detta i tanke, så försöker detta examensarbete att fokusera på ljud för mobila användare i ett försök att skapa mer användbara apparater genom att utnyttja ”context-awareness”.

Our hunger for data has grown tremendously over the years which has led to a demand for the increase in the available radio spectrum for communications. The Federal Communications Commission in the United States allowed for the sharing of the CBRS band (3550-3700 MHz) a few years ago. Since then, research has been done by both industry and academia to identify similar opportunities in other radio bands as well. This research is, however, being hampered due to a lack of experimental frameworks where the various aspects of spectrum sharing can be studied. To this end, we propose to develop an open-source spectrum access system that incorporates context awareness and multi-band operational support and serves as an RandD tool for the research community. We have developed a novel Prioritization Framework that takes the current operational context of each user into account to determine their relative priority, within or outside their user class/group, for transmission in the network. We also introduce a Policy Engine for the configuration and management of dynamic policies (or rules) for defining the relationships between the various forms of context information and their relative impact on a user's overall priority. We have performed several experiments to show how context awareness impacts the spectrum sharing efficiency and quality of service. Due to its modular and extensible nature, we expect that this tool will be used by researchers and policy-makers to implement their own policies and algorithms and test their efficacy in a simulated radio environment. / Master of Science / Over the years, the advancements in the internet and communication technology have made us more and more data-hungry. Consequently, the electromagnetic spectrum on which data is transmitted has become a sparse resource. Governments worldwide are working together with academia and industry to find the most efficient utilization of this resource. If the current users of protected spectrum could share their bands with other licensed or opportunistic users, then a tremendous amount of spectrum could be freed up for public and private use. To facilitate rapid research and development in this field, this thesis proposes the development of an open-source, modular, and extensible Context-Aware Dynamic Spectrum Access System. In this system, we explore the usage of several traditional and novel context information in spectrum allocation, which in turn helps us improve the efficiency and resiliency of spectrum management while ensuring that incumbent users are not adversely affected by other licensed or unlicensed users. We develop cognitive modules for context-based prioritization of users for allocation through a novel Prioritization Framework and for enabling the use of dynamic policies or rules (governing spectrum allocation) instead of static policies that most systems use today. We simulate several operational scenarios and depict our tool's performance in them. Through our experiments and discussions, we highlight the significance of this tool for researchers, policy-makers, and regulators for studying spectrum sharing in general, and context-aware, dynamic policy-based spectrum sharing in particular.