Self-adaptation via concurrent multi-action evaluation for unknown context

Context-aware computing has been attracting growing attention in recent years. Generally, there are several ways for a context-aware system to select a course of action for a particular change of context. One way is for the system developers to encompass all possible context changes in the domain knowledge. Other methods include system inferences and adaptive learning whereby the system executes one action and evaluates the outcome and self-adapts/self-learns based on that. However, in situations where a system encounters unknown contexts, the iterative approach would become unfeasible when the size of the action space increases. Providing efficient solutions to this problem has been the main goal of this research project. Based on the developed abstract model, the designed methodology replaces the single action implementation and evaluation by multiple actions implemented and evaluated concurrently. This parallel evaluation of actions speeds up significantly the evolution time taken to select the best action suited to unknown context compared to the iterative approach. The designed and implemented framework efficiently carries out concurrent multi-action evaluation when an unknown context is encountered and finds the best course of action. Two concrete implementations of the framework were carried out demonstrating the usability and adaptability of the framework across multiple domains. The first implementation was in the domain of database performance tuning. The concrete implementation of the framework demonstrated the ability of concurrent multi-action evaluation technique to performance tune a database when performance is regressed for an unknown reason. The second implementation demonstrated the ability of the framework to correctly determine the threshold price to be used in a name-your-own-price channel when an unknown context is encountered. In conclusion the research introduced a new paradigm of a self-adaptation technique for context-aware application. Among the existing body of work, the concurrent multi-action evaluation is classified under the abstract concept of experiment-based self-adaptation techniques

Scalable User Interfaces for the Web / by Arman Danesh.

This thesis describes a new approach to developing and delivering user interfaces for Web applications. This approach, termed Scalable User Interfaces (SUI), is designed to allow a developer to create a single user interface definition for a Web application which can then be consumed, rendered and used by any device on the network. These devices can range from small displays such as mobile telephones to the full desktop-sized monitor displays used by personal computers. The goal of Scalable User Interfaces is to allow a single specification to be deployed on all devices without the need for the developer to specify any device-specific vocabularies, transformations, hinting or style sheets such as previous work in automated rendering for mixed displays and work in platform-independent user interface specification. Scalable User Interfaces provides a Flash-based implementation which highlights the utility of Flash as a tool for user interface design and research. Our work also illustrates the application of recursive rendering in laying out forms for various-sized displays

An Engineering Method for Adaptive, Context-aware Web Applications

Users of Web-based software encounter growing complexity of the software resulting from the increasing amount of information and service offering. As a consequence, the likelihood that users employ the software in a manner compatible with the provider's interest decreases. Depending on the purpose of the Web application, a provider's goal can be to guide and influence user choices in information and service selection, or to assure user productivity. An approach at addressing these goals is to adapt the software's behavior during operation to the context in which it is being used. The term context-awareness originates in mobile computing, where research projects have studied context recognition and adaptation in specific scenarios. Context-awareness is now being studied in a variety of systems, including Web applications. However, how to account for context in a Web Engineering process is not yet established, nor is a generic means of using context in a Web software architecture. This dissertation addresses the question of how context-awareness can be applied in a general-purpose, systematic process for Web application development: that is, in a Web Engineering process. A model for representing an application's context factors in ontologies is presented. A general-purpose methodology for Web Engineering is extended to account for context, by putting in relation context ontologies with elements of the application domain. The application model is extended with adaptation specifications, defining at which places in the application adaptation to context is to occur, and according to what strategy. Application and context models are system interpretable, in order to support automatic adaptation of a system's behavior during its operation, that is, consequently to user requests. Requirements for a corresponding Web software architecture for context are established first at the conceptual level, then specifically in a content-based architecture based on an XML stack. The CATWALK software framework, an implementation of an architecture enabling adaptation to context is described. The framework provides mechanisms for interpreting application and context models to generate an adaptive application, meaning to generate responses to user requests, where the generation process makes decisions based on context information. For this purpose, the framework contains default implementations for context recognition and adaptation mechanisms. The approach presented supports a model-based development of Web applications which adapt to context. The CATWALK framework is an mplementation for model interpretation in a run-time system and thus simplifies the development of Web applications which adapt to context. As the framework is component-based and follows a strict separation of concerns, the default mechanisms can be extended or replaced, allowing to reduce the amount of custom code required to implement specific context-aware Web applications or to study alternative context inference or adaptation strategies. The use of the framework is illustrated in a case study, in which models are defined for a prototypical application, and this application is generated by the framework. The purpose of the case study is to illustrate effects of adaptation to context, based on context description and adaptation specifications in the application model