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2003 | Book

Building World Models by Ray-Tracing within Ceiling-Mounted Positioning Systems Read chapter Read first chapter

UbiComp 2003: Ubiquitous Computing

5th International Conference, Seattle, WA, USA, October 12-15, 2003. Proceedings

Editors: Anind K. Dey, Albrecht Schmidt, Joseph F. McCarthy

Publisher: Springer Berlin Heidelberg

Book Series : Lecture Notes in Computer Science

Included in: Professional Book Archive

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About this book

UbiComp 2003, the 5th Annual Conference on Ubiquitous Computing, is the premier forum for presentation of research results in all areas relating to the - sign, implementation, deployment and evaluation of ubiquitous computing te- nologies. The conference brings together leading researchers, from a variety of disciplines, perspectives and geographical areas, who are exploring the impli- tions of computing as it moves beyond the desktop and becomes increasingly interwoven into the fabrics of our lives. This volume, the conference proceedings, contains the entire collection of high-quality full papers and technical notes from UbiComp 2003. There were 16 full papers in this year’s conference, selected by our international program committee from among 117 submissions. There were also 11 technical notes in the program: 8 taken from the 36 technical note submissions, and 3 that were adapted from full paper submissions. We are very grateful to Tim Kindberg and Bernt Schiele, our Technical Notes Co-chairs, and to all the authors and reviewers of both papers and technical notes who contributed to maintaining the high standards of quality for the conference. In addition to the full papers and technical notes, UbiComp 2003 also p- vided a number of other participation categories, including workshops, dem- strations, interactive posters, a panel, a doctoral colloquium and a video p- gram. While accepted submissions in these categories were also of high quality, timing and size constraints prevented us from including them in this volume.

Table of Contents

Frontmatter

Location and Space

Building World Models by Ray-Tracing within Ceiling-Mounted Positioning Systems
Abstract
Context-aware computing in location-aware environments demands the combination of real world position with a computational world model to infer context. We present a novel approach to building world models using signals inherent in positioning systems, building on the work of the robotics research field.
We implement the approach using the Bat ultrasonic location system. We observe excellent results when trying to extract the height and shape of horizontal surfaces, and demonstrate how to image and characterise object volumes.
Results are collected using personnel Bats and by using an autonomous vehicle which moves randomly. In both cases, the results are accurate and reliable.
Robert K. Harle, Andy Hopper
On a Location Model for Fine-Grained Geocast
Abstract
Geographic communication (geocast) is used to send messages to geographic areas, e.g. to distribute warning messages or other information within these areas. It is based on a location model which is used to define a message’s target area and the receivers’ positions and therefore has strong influence on the achievable granularity of geographic addressing.
A hybrid location model and a fine-grained addressing scheme for geocast based on this model are presented in this paper which support two- and three-dimensional geometric locations as well as symbolic locations like room numbers, embedded local coordinate systems, and mobile target areas like trains.
Frank Dürr, Kurt Rothermel
RightSPOT: A Novel Sense of Location for a Smart Personal Object
Abstract
One of the main prerequisites for location-based services is knowledge of location. We present a simple algorithm for computing the location of a device based on signal strengths from FM radio stations. The motivation for this method comes from a new class of smart personal objects that will receive digital data encoded in regular FM radio broadcasts. Given their built-in ability to receive FM and to measure signal strengths, we show how to exploit this ability to measure the device’s location. Our algorithm, called RightSPOT, is designed to be robust to manufacturing variations among devices that affect how they measure signal strength. Toward this end, we present a location classification algorithm based not on absolute signal strengths, but on a ranking of signal strengths from multiple FM radio stations. In tests with three devices in six suburban areas, we show that we can correctly infer the device’s location about 80% of the time.
John Krumm, Gerry Cermak, Eric Horvitz
User-Friendly Surveying Techniques for Location-Aware Systems
Abstract
Many location-aware applications rely on data from fine-grained location systems. During deployment such systems require a survey, specifying the locations of their environment-based components. Most current surveying methods are time-consuming, and require costly and bulky equipment.
This paper presents the concept of self-surveying, i.e. methods by which a location system can survey itself. Such methods are user-friendly, fast, and require little or no extra equipment. Experimental results show self-survey accuracies comparable to the accuracy of the underlying location system.
James Scott, Mike Hazas

Modeling and Inference

Sto(ry)chastics: A Bayesian Network Architecture for User Modeling and Computational Storytelling for Interactive Spaces
Abstract
This paper presents sto(ry)chastics, a user-centered approach for computational storytelling for real-time sensor-driven multimedia audiovisual stories, such as those that are triggered by the body in motion in a sensor-instrumented interactive narrative space. With sto(ry)chastics the coarse and noisy sensor inputs are coupled to digital media outputs via a user model, which is estimated probabilistically by a Bayesian network. To illustrate sto(ry)chastics, this paper describes the museum wearable, a device which delivers an audiovisual narration interactively in time and space to the visitor as a function of the estimated visitor type. The wearable relies on a custom-designed long-range infrared location-identification sensor to gather information on where and how long the visitor stops in the museum galleries and uses this information as input to, or observations of, a (dynamic) Bayesian network. The network has been tested and validated on observed visitor tracking data by parameter learning using the Expectation Maximization (EM) algorithm, and by performance analysis of the model with the learned parameters.
Flavia Sparacino
Inferring High-Level Behavior from Low-Level Sensors
Abstract
We present a method of learning a Bayesian model of a traveler moving through an urban environment. This technique is novel in that it simultaneously learns a unified model of the traveler’s current mode of transportation as well as his most likely route, in an unsupervised manner. The model is implemented using particle filters and learned using Expectation-Maximization. The training data is drawn from a GPS sensor stream that was collected by the authors over a period of three months. We demonstrate that by adding more external knowledge about bus routes and bus stops, accuracy is improved.
Donald J. Patterson, Lin Liao, Dieter Fox, Henry Kautz
Activity Zones for Context-Aware Computing
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.
Kimberle Koile, Konrad Tollmar, David Demirdjian, Howard Shrobe, Trevor Darrell

Context Awareness

Context-Aware User Authentication – Supporting Proximity-Based Login in Pervasive Computing
Abstract
This paper explores computer security in pervasive computing with focus on user authentication. We present the concept of Proximity-Based User Authentication, as a usability-wise ideal for UbiComp systems. We present a context-aware user authentication protocol, which (1) uses a JavaCard for identification and cryptographic calculations, (2) uses a context-awareness system for verifying the user’s location, and (3) implements a security fall-back strategy. We analyze the security of this protocol and discuss the tradeoff between usability and security. We also present our current implementation of the protocol and discuss future work.
Jakob E. Bardram, Rasmus E. Kjær, Michael Ø Pedersen
Secure Spontaneous Device Association
Abstract
One of the principal requirements of ubiquitous computing is support for spontaneous interoperation, in which two or more devices interact temporarily in ad hoc circumstances. Spontaneity typically arises when nomadic users carry one or more of the devices around. We contribute a method of using lasers for securing spontaneous device associations. The method provides users with physical evidence of which device they have connected their device to, as well as setting up a secure channel between the devices.
Tim Kindberg, Kan Zhang
AwareCon: Situation Aware Context Communication
Abstract
Ubicomp environments impose tough constraints on networks, including immediate communication, low energy consumption, minimal maintenance and administration. With the AwareCon network, we address these challenges by prescribing an integrated architecture that differs from classical networking, as it features an awareness of the surrounding situation and context. In various settings, where AwareCon was implemented on tiny battery driven devices, we show that applications and usability of devices benefit from this approach.
Michael Beigl, Albert Krohn, Tobias Zimmer, Christian Decker, Philip Robinson
liquid: Context-Aware Distributed Queries
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 liquidsystem, and presents both a room-awareness application and notification service demonstrating its functionality.
Jeffrey Heer, Alan Newberger, Chris Beckmann, Jason I. Hong
Is Context-Aware Computing Taking Control away from the User? Three Levels of Interactivity Examined
Abstract
Context-aware computing promises a smooth interaction between humans and technology but few studies have been conducted with regards to how autonomously an application should perform. After defining three levels of interactivity between a mobile computing device and its user: personalization, passive context-awareness and active context-awareness, we test which approach will limit users’ perceived sense of control. We also investigate users’ preferences for the three approaches. We conducted an experimental case study, using mobile phone applications to exemplify the three levels of interactivity. Our study shows that users feel less in control when using either passive or active context-aware applications than when personalizing their own applications. Despite this we also find that context-aware applications are preferred over the personalization oriented ones. We conclude that people are willing to give up partial control if the reward in usefulness is great enough.
Louise Barkhuus, Anind Dey

New Devices and Technologies

Tools for Studying Behavior and Technology in Natural Settings
Abstract
Three tools for acquiring data about people, their behavior, and their use of technology in natural settings are described: (1) a context-aware experience sampling tool, (2) a ubiquitous sensing system that detects environmental changes, and (3) an image-based experience sampling system. We discuss how these tools provide researchers with a flexible toolkit for collecting data on activity in homes and workplaces, particularly when used in combination. We outline several ongoing studies to illustrate the versatility of these tools. Two of the tools are currently available to other researchers to use.
Stephen S. Intille, Emmanuel Munguia Tapia, John Rondoni, Jennifer Beaudin, Chuck Kukla, Sitij Agarwal, Ling Bao, Kent Larson
Very Low-Cost Sensing and Communication Using Bidirectional LEDs
Abstract
A novel microprocessor interface circuit is described which can alternately emit and detect light using only an LED, two digital I/O pins and a single current limiting resistor. This technique is first applied to create a smart illumination system that uses a single LED as both light source and sensor. We then present several devices that use an LED as a generic wireless serial data port. An important implication of this work is that every LED connected to a microprocessor can be thought of as a wireless two-way communication port. We present this technology as a solution to the “last centimeter problem”, because it permits disparate devices to communicate with each other simply and cheaply with minimal design modification.
Paul Dietz, William Yerazunis, Darren Leigh
SPECs: Another Approach to Human Context and Activity Sensing Research, Using Tiny Peer-to-Peer Wireless Computers
Abstract
A small battery powered peer-to-peer proximity sensing platform that can be attached to people, places and things can be a valuable tool to conduct research in human activity sensing. Such a platform senses the subjects’ presence and activities in a wide variety of contexts, for example home, car, work, or shopping. It eliminates the need for deployment and maintenance of prohibitively expensive infrastructure. The goal is to sense the activities of one individual at large in their world, rather than the activities of a group in a well- instrumented laboratory setting. Preliminary results with a real-world application are described.
Mik Lamming, Denis Bohm
A 2-Way Laser-Assisted Selection Scheme for Handhelds in a Physical Environment
Abstract
We present a 2-way selection method to select objects in a physical environment with a novel feedback and transfer of control mechanism. A modulated laser pointer signal sent from a handheld device triggers a photosensitive tag placed in the environment. The tag responds via a standard wireless channel directly to the handheld with information regarding an object it represents. We describe a prototype implementation for a Motorola iDEN i95cl cell phone, discuss the interaction challenges and application possibilities for this physical world selection that extends a common handheld device. We also compare this solution to related attempts in the literature.
Shwetak N. Patel, Gregory D. Abowd

Domestic Environments and Healthcare

Finding a Place for UbiComp in the Home
Abstract
The movement of design out of the workplace and into the home brings with it the need to develop new analytic concepts to consider how ubiquitous computing might relate to and support everyday activities in domestic settings. In this paper we present a number of concepts derived from ethnographic studies of routine activities and technology uses implicated in the production and consumption of communication in the home. These concepts sensitise design to the importance of the ecology of the domestic space and distributed arrangements of collaboration to communication. They draw attention to the places where communication is accomplished and the routines whereby communication is articulated, thereby highlighting ‘prime sites’ for situating ubiquitous computing in the domestic environment.
Andy Crabtree, Tom Rodden, Terry Hemmings, Steve Benford
New Perspectives on Ubiquitous Computing from Ethnographic Study of Elders with Cognitive Decline
Abstract
A rapidly growing elder population is placing unprecedented demands on health care systems around the world. Cognitive decline is one of the most taxing health problems in terms of both its relation to elders’ overall functioning and the cost of care. The needs of elders with cognitive decline – for invisible, intuitive support and assessment – invite a reconsideration of the assumptions behind and specifications for ubiquitous computing solutions. This paper describes findings and implications of ethnographic research conducted with cognitively impaired individuals and their informal care networks in 45 households in 5 U.S. regions. Key themes regarding needs and barriers to successful aging are addressed through a set of design principles which apply across the stages of cognitive decline. To convey stage-specific findings and associated challenges for ubiquitous computing, case studies of four representative households and example concept solutions are presented. The design principles and technology challenges outlined in this paper may generalize to other contexts for ubiquitous computing.
Margaret Morris, Jay Lundell, Eric Dishman, Brad Needham
Practical Considerations of Context for Context Based Systems: An Example from an Ethnographic Case Study of a Man Diagnosed with Early Onset Alzheimer’s Disease
Abstract
The meaning of context with respect to computational systems has been the focus of considerable discussion specifically as related to context aware and proactive computing. However, there are no reports of people’s direct, experiential understanding of the “lived experience” of context. As a result, there is a significant gap between theoretical approaches for understanding context and the actual practice of context, which is critical for the specification of systems. This paper reports the results of an ethnographic case study that illuminates the practical nature of context and highlights specific challenges for ubiquitous computing systems in general. We conclude that context is simultaneously more subtle, fluid and idiosyncratic than previously reported under theoretical approaches to understanding context. We further suggest implications for the design of computing systems based on these findings.
Tony Salvador, Ken Anderson
“Playing with the Bits” User-Configuration of Ubiquitous Domestic Environments
Abstract
This paper presents the development of a user-oriented framework to support the user reconfiguration of ubiquitous domestic environments. We present a lightweight component model that allows a range of devices to be readily interconnected and an editor to support users in doing this. The editor discovers available ubiquitous components and presents these to users as jigsaw pieces that can be dynamically recombined. The developed editor allows users to assemble lightweight sensors, devices such as displays and larger applications in order to meet their particular needs.
Jan Humble, Andy Crabtree, Terry Hemmings, Karl-Petter Åkesson, Boriana Koleva, Tom Rodden, Pär Hansson

Social Aspect and Privacy

IntelliBadgeTM: Towards Providing Location-Aware Value-Added Services at Academic Conferences
Abstract
This paper contains details on a project aimed to provide location-aware value- added services to the participants of an academic conference. The major characteristic of this project is the fusion of RFID technology, database management, data mining, real-time information visualization, and interactive web application technologies into an operational integrated system deployed at a major public conference. The developed system tracks conference attendees, analyzes the tracking data in real-time and provides various services to the attendees, such as a real-time snapshot of the conference events attendance, the ability to locate friends in the convention center, and the ability to search for events of interest. The results of this experiment were revealing in terms of both the potential of the developed technology and the conference dynamics.
Donna Cox, Volodymyr Kindratenko, David Pointer
UbiTable: Impromptu Face-to-Face Collaboration on Horizontal Interactive Surfaces
Abstract
Despite the mobility enabled by the plethora of technological tools such as laptops, PDA and cell phones, horizontal flat surfaces are still extensively used and much preferred for on-the-move face-to-face collaboration. Unfortunately, when digital documents need to be shared during collaboration, people are still mostly constrained to display surfaces that have been designed for single users, such as laptops and PDAs. Technologically there is a lack of computational support for shared digital document access, browsing, visualization and manipulation on horizontal surfaces. We believe support for such serendipitous meetings will play a critical role in future ubiquitous computing spaces. Our UbiTable project examines the design space of tabletops used as scrap displays. Scrap displays support kiosk-style walk-up interaction for impromptu face-to-face collaboration. Our design offers the affordances of a physical table. It provides the flexibility by allowing users to layout shared documents with desired orientation and position; at the same time it augments traditional paper-based interactions by providing a flexible gradient or shades of sharing semantics. UbiTable addresses visual accessibility vs. electronic accessibility of documents, an issue which is critical to ubiquitous environments.
Chia Shen, Katherine Everitt, Kathleen Ryall
Social Network Computing
Abstract
A ubiquitous wearable computing infrastructure is now firmly entrenched within organizations across the globe, yet much of its potential remains untapped. This paper describes how the handheld computers and mobile phones in today’s organizations can be used to quantify face-to-face interactions and to infer aspects about a user’s situation, enabling more creative and transparent functioning of human organizations.
Nathan Eagle, Alex (Sandy) Pentland
The Design of a Context-Aware Home Media Space for Balancing Privacy and Awareness
Abstract
Traditional techniques for balancing privacy and awareness in video media spaces, like blur filtration, have been proven to be ineffective for compromising home situations involving a media space. As such, this paper presents the rationale and prototype design of a context-aware home media space (HMS) – defined as an always-on video media space used within a home setting – that focuses on identifying plausible solutions for balancing privacy and awareness in compromising home situations. In the HMS design, users are provided with implicit and explicit control over their privacy, along with visual and audio feedback of the amount of privacy currently being maintained.
Carman Neustaedter, Saul Greenberg

New Interfaces

Context-Aware Computing with Sound
Abstract
We propose audio networking: using ubiquitously available sound hardware (i.e. speakers, sound-cards and microphones) for low-bandwidth, wireless networking. A variety of location- and context-aware applications that use audio networking are presented including a location system, a pick-and-drop interface and a framework for embedding digital attachments in voice notes or telephone conversations.
Audio networking has a number of interesting characteristics that differentiate it from existing wireless networking technologies: (i) it offers fine-grained control over the range of transmission (since audio APIs allow fine-grained volume adjustment); (ii) walls of buildings are typically designed specifically to attenuate sound waves so one can easily contain transmission to a single room; (iii) it allows existing devices that record or play audio to be “brought into the user interface”; and (iv) it offers the potential to unify device-to-device and device-to-human communication.
Anil Madhavapeddy, David Scott, Richard Sharp
An Architecture and Framework for Steerable Interface Systems
Abstract
Steerable Interfaces are emerging as a new paradigm used in realizing the vision of embodied interaction in ubiquitous computing environments. Such interfaces steer relevant input and output capabilities around space, to serve the user when and where they are needed. We present an architecture and a programming framework that enable the development of Steerable Interface applications. The distributed multi-layer architecture provides applications with abstractions to services of several novel components – for instance, steerable projection, steerable visual interaction detection, and geometric reasoning. The programming framework facilitates integration of the various services while hiding the complexity of sequencing and synchronizing the underlying components.
Anthony Levas, Claudio Pinhanez, Gopal Pingali, Rick Kjeldsen, Mark Podlaseck, Noi Sukaviriya
Evaluation of Visual Notification Cues for Ubiquitous Computing
Abstract
With increased use of mobile information technology and increased amounts of information comes the need to simplify information presentation. This research considers whether low-information-rate displays (such as those used in mobile devices) can provide effective information awareness. An experiment was performed to measure the performance/size tradeoff of visual displays ranging in size from two LEDs to nine LEDs, and using a number of display characteristics – i.e., color and blinking in various combinations. Results show a reliable tradeoff between performance (participant response time and accuracy) and display size (number of LEDs). However, even the full set of 27 messages can be conveyed with high recognition accuracy using only three LEDs by mapping the messages into color and position. Thus, mobile devices with micro-level form factors can be designed to convey critical information and provide effective notifications. Future work and a prototype developed from this work are discussed.
Peter Tarasewich, Christopher S. Campbell, Tian Xia, Myra Dideles
Backmatter
Metadata
Title
UbiComp 2003: Ubiquitous Computing
Editors
Anind K. Dey
Albrecht Schmidt
Joseph F. McCarthy
Copyright Year
2003
Publisher
Springer Berlin Heidelberg
Electronic ISBN
978-3-540-39653-6
Print ISBN
978-3-540-20301-8
DOI
https://doi.org/10.1007/b93949