Privacy is the most often-cited criticism of ubiquitous computing, and may be the greatest barrier to its long-term success. However, developers currently have little support in designing software architectures and in creating interactions that are effective in helping end-users manage their privacy. To address this problem, we present Confab, a toolkit for facilitating the development of privacy-sensitive ubiquitous computing applications. The requirements for Confab were gathered through an analysis of privacy needs for both end-users and application developers. Confab provides basic support for building ubiquitous computing applications, providing a framework as well as several customizable privacy mechanisms. Confab also comes with extensions for managing location privacy. Combined, these features allow application developers and end-users to support a spectrum of trust levels and privacy needs.

and have found that it is complete and satisfactory in all respects, and that any and all revisions required by the final examining committee have been made.

MultiJava is a conservative extension of the Java programming language that adds symmetric multiple dispatch and open classes. Among other benefits, multiple dispatch provides a solution to the binary method problem. Open classes provide a solution to the extensibility problem of object-oriented programming languages, allowing the modular addition of both new types and new operations to an existing type hierarchy. This article illustrates and motivates the design of MultiJava and describes its modular static typechecking and modular compilation strategies. Although MultiJava extends Java, the key ideas of the language design are applicable to other object-oriented languages, such as C # and C++, and even, with some modifications, to functional languages such as ML. This article also discusses the variety of application domains in which MultiJava has been successfully used by others, including pervasive computing, graphical user interfaces, and compilers.

Based on an extensive field study of current firefighting practices, we have developed a system called Siren to support tacit communication between firefighters with multiple levels of redundancy in both communication and user alerts. Siren provides a foundation for gathering, integrating, and distributing contextual data, such as location and temperature. It also simplifies the development of firefighting applications using a peer-to-peer network of embedded devices through a uniform programming interface based on the information space abstraction. As a proof of concept, we have developed a prototype context -aware messaging application in the firefighting domain. We have evaluated this application with firefighters and they have found it to be useful for improving many aspects of their current work practices.

Abstract. Location is a primary cue in many context-aware computing systems, and is often represented as a global coordinate, room number, or a set of Euclidean distances to various landmarks. A user’s concept of location, however, is often defined in terms of regions in which similar activities occur. We discuss the concept of such regions, which we call activity zones, and suggest that such zones can be used to trigger application actions, retrieve information based on previous context, and present information to users. We show how to semi-automatically partition a space into activity zones based on patterns of observed user location and motion. We describe our system and two implemented example applications whose behavior is controlled by users ’ entry, exit, and presence in the zones. 1

The proliferation of wireless networks, hand-held PCs, touch panels, large flat displays, sensors, and embedded devices is transforming traditional habitats and living spaces into ubiquitous computing environments, or active spaces. We envision a middleware software infrastructure that abstracts the heterogeneity of these environments and transforms them into programmable environments. This middleware infrastructure provides support to manage the resources contained in an active space (low-level functionality), support to develop applications (application-level functionality), and support to define interaction rules among applications (active space-level functionality). In this paper, we present a mechanism called “application bridge ” that implements active space-level functionality. Application bridges provide a simple, yet effective, mechanism to define dynamic application composition interaction rules that confer the active space a specific behavior based on a number of parameters, including context, application status, and user actions. 1.

No matter which technologies or techniques a ubiquitous location system uses, its measurements will have some amount of quantifiable error.

The introduction of mobile code in the pervasive computing environment provides a good opportunity for research in ways to enhance execution flexibility. We note that current mobile code is too heavyweight and not adaptive enough to be used in pervasive computing where devices are resourcelimited and heterogeneity is the norm. In this paper, we propose a new lightweight, component-based mobile agent system that can adapt to diverse devices and features resource saving as one of its aims. The system supports strong mobility of mobile code, which is a prerequisite for achieving system flexibility and good performance. The system discretize the transmission of code and execution states and relies on a scheme called state-on-demand (SOD) for the execution of the mobile code. We provide performance results to demonstrate the effectiveness of the SOD scheme.

Abstract not found

Information flow applications like distributed continual queries, online scientific collaboration and visualization, and the operational information systems used by large corporations involve the acquisition, processing, and dissemination of events across distributed computing platforms. Multiple distinct middleware frameworks have been developed to support such data-intensive applications, including publish-subscribe systems, messaging infrastructures, and in-house solutions customized to specific business needs. This paper presents IFLOW, an overlay messaging framework that provides the basic functionality for realizing the multiple middleware models now present in commercial and academic endeavors. IFLOW offers (1) overlay management functions, used to construct, maintain, and manage the overlay networks across which information flows travel, (2)