This paper presents the "Solar" system framework that allows resources to advertise context-sensitive names and for applications to make context-sensitive name queries. The heart of our framework is a small specification language that allows composition of "context-processing operators" to calculate the desired context. Resources use the framework to register names, and applications use the framework to look up contextsensitive name descriptions. The back-end system executes these operators and constantly updates the context values, adjusting advertised names and informing applications about changes. We report experimental results from a prototype, using a modified version of the Intentional Naming System (INS) as the core directory service.

Abstract. As the trend towards technology-enriched home environments progresses, the need to enable users to create applications to suit their own lives increases. While several recent projects focus on lowering barriers for application creation by using simplified input mechanisms and languages, these projects often approach application creation from a developer’s perspective, focusing on devices and their interactions, rather than users ’ goals or tasks. In this paper, we present a study that examines how users conceptualize applications involving automated capture and playback of home activities and reveals a breadth of home applications that people desire. We introduce CAMP, a system that enables end-user programming for smart home environments based on a magnetic poetry metaphor. We describe how CAMP’s simple interface for creating applications supports users ’ natural conceptual models of capture applications. Finally, we present a preliminary evaluation of CAMP and assess its ability to support a breadth of desired home applications as well as the user’s conceptual model. 1

Context-sensing for context-aware HCI challenges the traditional sensor fusion methods with dynamic sensor configuration and measurement requirements commensurate with human perception. The Dempster-Shafer theory of evidence has uncertainty management and inference mechanisms analogous to our human reasoning process. Our Sensor Fusion for Context-aware Computing Project aims to build a generalizable sensor fusion architecture in a systematic way. This naturally leads us to choose the Dempster-Shafer approach as our first sensor fusion implementation algorithm. This paper discusses the relationship between Dempster-Shafer theory and the classical Bayesian method, describes our sensor fusion research work using Dempster-Shafer theory in comparison with the weighted sum of probability method. The experimental approach is to track a user's focus of attention from multiple cues. Our experiments show promising, thought-provoking results encouraging further research.

The emergence of pervasive networked data sources, such as web services, sensors, and mobile devices, enables context-sensitive, mobile applications. We have developed a programming model for writing such applications, in which entities called composers accept data from one or more sources, and act as sources of higher-level data. We have defined and implemented a nonprocedural language, iQL, specifying the behavior of composers. An iQL programmer expresses requirements for data sources rather than identifying specific sources; a runtime system discovers appropriate data sources, binds to them, and rebinds when properties of data sources change. The language has powerful operators useful in composition,

Load sensing is a mature and robust technology widely applied in process control. In this paper we consider the use of load sensing in everyday environments as an approach to acquisition of contextual information in ubiquitous computing applications. Since weight is an intrinsic property of all physical objects, load sensing is an intriguing concept on the physical-virtual boundary, enabling the inclusive use of arbitrary objects in ubiquitous applications. In this paper we aim to demonstrate that load sensing is a versatile source of contextual information. Using a series of illustrative experiments we show that using load sensing techniques we can obtain not just weight information, but object position and interaction events on a given surface. We describe the incorporation of load-sensing in the furniture and the floor of a living laboratory environment, and report on a number of applications that use context information derived from load sensing.

Context-aware computing is an emerging paradigm to free everyday users from manually configuring and instructing computer systems. As the general trend of computing is progressing towards an open and dynamic infrastructure, building context-aware systems can be difficult and costly. In order to build successful context-aware systems, we must develop an architecture to reduce the difficulty and cost of building these systems. This PhD. dissertation proposal describes a research plan to develop a broker-centric agent architecture that is aimed to relieve the burden of capability-limited agents of acquiring and reasoning about contexts, and to protect the privacy of users in a context-aware environment. The implementation of the Context Broker Archiecture will explore Web Ontology Language for modeling contexts and privacy policies, Jess for building a hybrid reasoning mechanism and JADE/FIPA for realizing broker behaviors and agent communications.

The mobility of wearable computers makes usability testing difficult. In order to fully understand how a user interacts with the wearable, the researcher must examine both the user's direct interactions with the computer, as well as the external context the user perceives during their interaction. We present a tool that augments a wearable computer with additional hardware and software to capture the information needed to perform a usability study in the field under realistic conditions. We examine the challenges in doing the capture and present our implementation. We also describe VizWear, a tool for examining the captured data. Finally, we present our experiences using the system for a sample user study. 1.

Ubiquitous computing challenges the conventional notion of a user logged into a personal computing device, whether it is a desktop, a laptop, or a digital assistant. When the physical environment of a user contains hundreds of networked computer devices each of which may be used to support one or more user applications, the notion of personal computing becomes inadequate. Further, when a group of users share such a physical environment, new forms of sharing, cooperation and collaboration are possible and mobile users may constantly change the computers with which they interact; we refer to these digitally augmented physical spaces as Active Spaces. We present in this paper an application framework that provides mechanisms to construct, run or adapt existing applications to ubiquitous computing environments. The framework binds applications to users, uses multiple devices simultaneously, and exploits resource management within the users' environment that reacts to context and mobility. Our research contributes to application mobility, partitioning and adaptation within device rich environments, and uses context-awareness to focus the resources of ubiquitous computing environments on the needs of users.

Abstract. As low-level architectural support for context-aware computing matures, we are ready to explore more general and powerful means of accessing context data. Information required by a context-aware application may be partitioned by any number of physical, organizational, or privacy boundaries. This suggests the need for mechanisms by which applications can issue context-sensitive queries without having to explicitly manage the complex storage layout and access policies of the underlying data. To address this need, we have developed liquid, a prototype query service that supports distributed, continuous query processing of context data. This paper articulates the current need for such systems, describes the design of the liquid system, and presents both a room-awareness application and notification service demonstrating its functionality. 1

EQUIP is a new software platform designed and engineered to support the development and deployment of distributed interactive systems, such as mixed reality user interfaces that combine distributed input and output devices to create a coordinated experience. EQUIP emphasises: cross-language development (currently C++ and Java), modularisation, extensibility, interactive performance, and heterogeneity of devices (from handheld devices to large servers and visualisation machines) and networks (including both wired and wireless technologies). A key element of EQUIP is its shared data service, which combines ideas from tuplespaces, general event systems and collaborative virtual environments. This data service provides a uniquely balanced treatment of state and event-based communication. It also supports distributed computation -- through remote class loading -- as well as passive data distribution. EQUIP has already been used in several projects within the EQUATOR Interdisciplinary Research Collaboration (IRC) in the UK, and is freely available in source form (currently known to work on Windows, IRIX and MacOS-X platforms).