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UBICOMP Tables of Contents: 01020304050607080910111213-113-214-114-215

Proceedings of the 2007 International Conference on Ubiquitous Computing

Fullname:Proceedings of the 9th International Conference on Ubiquitous Computing
Editors:John Krumm; Gregory D. Abowd; Aruna Seneviratne; Thomas Strang
Location:Innsbruck, Austria
Dates:2007-Sep-16 to 2007-Sep-19
Publisher:Springer Berlin Heidelberg
Series:Lecture Notes in Computer Science 4717
Standard No:DOI: 10.1007/978-3-540-74853-3 hcibib: UBICOMP07; ISBN: 978-3-540-74852-6 (print), 978-3-540-74853-3 (online)
Links:Online Proceedings | Conference Website
  1. Health
  2. Privacy and Security
  3. Domestic
  4. Location
  5. Issues in Mobility
  6. Activity Sensing
  7. Case Studies
  8. Networking
  9. The Design Process
  10. Activity Sensing


A Statistical Reasoning System for Medication Prompting BIBAFull-Text 1-18
  Sengul Vurgun; Matthai Philipose; Misha Pavel
We describe our experience building and using a reasoning system for providing context-based prompts to elders to take their medication. We describe the process of specification, design, implementation and use of our system. We chose a simple Dynamic Bayesian Network as our representation. We analyze the design space for the model in some detail. A key challenge in using the model was the overhead of labeling the data. We analyze the impact of a variety of options to ease labeling, and highlight in particular the utility of simple clustering before labeling. A key choice in the design of such reasoning systems is that between statistical and deterministic rule-based approaches. We evaluate a simple rule-based system on our data and discuss some of its pros and cons when compared to the statistical (Bayesian) approach in a practical setting. We discuss challenges to reasoning arising from failures of data collection procedures and calibration drift. The system was deployed among 6 subjects over a period of 12 weeks, and resulted in adherence improving from 56% on average with no prompting to 63% with state of the art context-unaware prompts to 74% with our context-aware prompts.
Tracking Free-Weight Exercises BIBAFull-Text 19-37
  Keng-hao Chang; Mike Y. Chen; John Canny
Weight training, in addition to aerobic exercises, is an important component of a balanced exercise program. However, mechanisms for tracking free weight exercises have not yet been explored. In this paper, we study methods that automatically recognize what type of exercise you are doing and how many repetitions you have done so far. We incorporated a three-axis accelerometer into a workout glove to track hand movements and put another accelerometer on a user's waist to track body posture. To recognize types of exercises, we tried two methods: a Naïve Bayes Classifier and Hidden Markov Models. To count repetitions developed and tested two algorithms: a peak counting algorithm and a method using the Viterbi algorithm with a Hidden Markov Model. Our experimental results showed overall recognition accuracy of around 90% over nine different exercises, and overall miscount rate of around 5%. We believe that the promising results will potentially contribute to the vision of a digital personal trainer, create a new experience for exercising, and enable physical and psychological well-being.
Playful Tray: Adopting Ubicomp and Persuasive Techniques into Play-Based Occupational Therapy for Reducing Poor Eating Behavior in Young Children BIBAFull-Text 38-55
  Jin-Ling Lo; Tung-yun Lin; Hao-hua Chu; Hsi-Chin Chou; Jen-hao Chen; Jane Yung-jen Hsu; Polly Huang
This study has created the Playful Tray that adopts Ubicomp and persuasive techniques into play-based occupational therapy for reducing poor eating behavior in young children after they reached their self-feeding age. The design of the Playful Tray reinforces active participation of children in the activity of eating by integrating digital play with eating. Results of a pilot user study suggest that the Playful Tray may improve child meal completion time and reduce negative power play interactions between parents and children, resulting in an improved family mealtime experience.

Privacy and Security

Privacy Enhancing Technologies for RFID in Retail -- An Empirical Investigation BIBAKFull-Text 56-72
  Sarah Spiekermann
This article investigates the conflicting area of user benefits arising through item level RFID tagging and a desire for privacy. It distinguishes between three approaches feasible to address consumer privacy concerns. One is to kill RFID tags at store exits. The second is to lock tags and have user unlock them if they want to initiate reader communication (user scheme). The third is to let the network access users' RFID tags while adhering to a privacy protocol (agent scheme). The perception and reactions of future users to these three privacy enhancing technologies (PETs) are compared in the present article and an attempt is made to understand the reasoning behind their preferences. The main conclusion is that users don't trust complex PETs as they are envisioned today. Instead they prefer to kill RFID chips at store exits even if they appreciate after sales services. Enhancing trust through security and privacy 'visibility' as well as PET simplicity may be the road to take for PET engineers in UbiComp.
Keywords: RFID; privacy; security; privacy enhancing technology; RFID killfunction; authentication; identification; user behavior
Ninja: Non Identity Based, Privacy Preserving Authentication for Ubiquitous Environments BIBAKFull-Text 73-90
  Adrian Leung; Chris J. Mitchell
Most of today's authentication schemes involve verifying the identity of a principal in some way. This process is commonly known as entity authentication. In emerging ubiquitous computing paradigms which are highly dynamic and mobile in nature, entity authentication may not be sufficient or even appropriate, especially if a principal's privacy is to be protected. In order to preserve privacy, other attributes (e.g. location or trustworthiness) of the principal may need to be authenticated to a verifier. In this paper we propose Ninja: a non-identity-based authentication scheme for a mobile ubiquitous environment, in which the trustworthiness of a user's device is authenticated anonymously to a remote Service Provider (verifier), during the service discovery process. We show how this can be achieved using Trusted Computing functionality.
Keywords: Security; Privacy; Ubiquitous; Trusted Computing
Field Deployment of IMBuddy: A Study of Privacy Control and Feedback Mechanisms for Contextual IM BIBAKFull-Text 91-108
  Gary Hsieh; Karen P. Tang; Wai Yong Low; Jason I. Hong
We describe the design of privacy controls and feedback mechanisms for contextual IM, an instant messaging service for disclosing contextual information. We tested our designs on IMBuddy, a contextual IM service we developed that discloses contextual information, including interruptibility, location, and the current window in focus (a proxy for the current task). We deployed our initial design of IMBuddy's privacy mechanisms for two weeks with ten IM users. We then evaluated a redesigned version for four weeks with fifteen users. Our evaluation indicated that users found our group-level rule-based privacy control intuitive and easy to use. Furthermore, the set of feedback mechanisms provided users with a good awareness of what was disclosed.
Keywords: Contextual instant messaging; context-aware; IM; privacy


Yours, Mine and Ours? Sharing and Use of Technology in Domestic Environments BIBAKFull-Text 109-126
  A. J. Bernheim Brush; Kori M. Inkpen
Domestic technologies have been a popular area of study for ubiquitous computing researchers, however there is relatively little recent data on how families currently use and share technologies in domestic environments. This paper presents results from an empirical study of 15 families in the U.S in early 2007. We examined the types of technologies families own, including TVs, music players, phones and computers; where they were situated within the home; and the degree of shared ownership and use. Our results call attention to the prevalence of shared usage of technology in domestic environments and also suggest opportunistic spaces for ubiquitous computing technology. While not all ubiquitous computing technologies for domestic environments will be shared, the diverse ways families chose to share their computers suggest that future devices might better match how families wish to use shared technology by supporting both the shared usage model of appliances and the ability to access a personal profile.
Keywords: domestic technology; home; sharing; empirical studies; login
How Smart Homes Learn: The Evolution of the Networked Home and Household BIBAKFull-Text 127-144
  Marshini Chetty; Ja-Young Sung; Rebecca E. Grinter
Despite a growing desire to create smart homes, we know little about how networked technologies interact with a house's infrastructure. In this paper, we begin to close this gap by presenting findings from a study that examined the relationship between home networking and the house itself -- and the work that results for householders as a consequence of this interaction. We discuss four themes that emerged: an ambiguity in understanding the virtual boundaries created by wireless networks, the home network control paradox, a new home network access paradox, and the relationship between increased responsibilities and the possibilities of wireless networking.
Keywords: home networking; smart home; infrastructure
"My Roomba Is Rambo": Intimate Home Appliances BIBAKFull-Text 145-162
  Ja-Young Sung; Lan Guo; Rebecca E. Grinter; Henrik I. Christensen
Robots have entered our domestic lives, but yet, little is known about their impact on the home. This paper takes steps towards addressing this omission, by reporting results from an empirical study of iRobot's Roomba™, a vacuuming robot. Our findings suggest that, by developing intimacy to the robot, our participants were able to derive increased pleasure from cleaning, and expended effort to fit Roomba into their homes, and shared it with others. These findings lead us to propose four design implications that we argue could increase people's enthusiasm for smart home technologies.
Keywords: Empirical study; home; robot; intimacy


Symbolic Object Localization Through Active Sampling of Acceleration and Sound Signatures BIBAFull-Text 163-180
  Kai Kunze; Paul Lukowicz
We describe a novel method for symbolic location discovery of simple objects. The method requires no infrastructure and relies on simple sensors routinely used in sensor nodes and smart objects (acceleration, sound). It uses vibration and short, narrow frequency 'beeps' to sample the response of the environment to mechanical stimuli. The method works for specific locations such as 'on the couch', 'in the desk drawer' as well as for location classes such as 'closed wood compartment' or 'open iron surface'. In the latter case, it is capable of generalizing the classification to locations the object has not seen during training. We present the results of an experimental study with a total of over 1200 measurements from 35 specific locations (taken from 3 different rooms) and 12 abstract location classes. It includes such similar locations as the inner and outer pocket of a jacket and a table and shelf made of the same wood. Nonetheless on locations from a single room (16 in the largest one) we achieve a recognition rate of up to 96%. It goes down to 81% if all 35 locations are taken together, however the correct location is in the 3 top picks of the system 94% of the times.
An Exploration of Location Error Estimation BIBAFull-Text 181-198
  David Dearman; Alex Varshavsky; Eyal de Lara; Khai N. Truong
Many existing localization systems generate location predictions, but fail to report how accurate the predictions are. This paper explores the effect of revealing the error of location predictions to the end-user in a location finding field study. We report findings obtained under four different error visualization conditions and show significant benefit in revealing the error of location predictions to the user in location finding tasks. We report the observed influences of error on participants' strategies for location finding. Additionally, given the observed benefit of a dynamic estimate of error, we design practical algorithms for estimating the error of a location prediction. Analysis of the algorithms shows a median estimation inaccuracy of up to 50m from the predicted location's true error.
Security by Spatial Reference: Using Relative Positioning to Authenticate Devices for Spontaneous Interaction BIBAFull-Text 199-216
  Rene Mayrhofer; Hans Gellersen; Mike Hazas
Spontaneous interaction is a desirable characteristic associated with mobile and ubiquitous computing. The aim is to enable users to connect their personal devices with devices encountered in their environment in order to take advantage of interaction opportunities in accordance with their situation. However, it is difficult to secure spontaneous interaction as this requires authentication of the encountered device, in the absence of any prior knowledge of the device. In this paper we present a method for establishing and securing spontaneous interactions on the basis of spatial references that capture the spatial relationship of the involved devices. Spatial references are obtained by accurate sensing of relative device positions, presented to the user for initiation of interactions, and used in a peer authentication protocol that exploits a novel mechanism for message transfer over ultrasound to ensures spatial authenticity of the sender.

Issues in Mobility

Users and Batteries: Interactions and Adaptive Energy Management in Mobile Systems BIBAFull-Text 217-234
  Nilanjan Banerjee; Ahmad Rahmati; Mark D. Corner; Sami Rollins; Lin Zhong
Battery lifetime has become one of the top usability concerns of mobile systems. While many endeavors have been devoted to improving battery lifetime, they have fallen short in understanding how users interact with batteries. In response, we have conducted a systematic user study on battery use and recharge behavior, an important aspect of user-battery interaction, on both laptop computers and mobile phones. Based on this study, we present three important findings: 1) most recharges happen when the battery has substantial energy left, 2) a considerable portion of the recharges are driven by context (location and time), and those driven by battery levels usually occur when the battery level is high, and 3) there is great variation among users and systems. These findings indicate that there is substantial opportunity to enhance existing energy management policies, which solely focus on extending battery lifetime and often lead to excess battery energy upon recharge, by adapting the aggressiveness of the policy to match the usage and recharge patterns of the device. We have designed, deployed, and evaluated a user- and statistics-driven energy management system, Llama, to exploit the battery energy in a user-adaptive and user-friendly fashion to better serve the user. We also conducted a user study after the deployment that shows Llama effectively harvests excess battery energy for a better user experience (brighter display) or higher quality of service (more application data) without a noticeable change in battery lifetime.
An Empirical Study of the Potential for Context-Aware Power Management BIBAFull-Text 235-252
  Colin Harris; Vinny Cahill
Context-aware power management (CAPM) uses context (e.g., user location) likely to be available in future ubiquitous computing environments, to effectively power manage a building's energy consuming devices. The objective of CAPM is to minimise overall energy consumption while maintaining user-perceived device performance.
   The principal context required by CAPM is when the user is not using and when the user is about to use a device. Accurately inferring this user context is challenging and there is a balance between how much energy additional context can save and how much it will cost energy wise. This paper presents results from a detailed user study that investigated the potential of such CAPM.
   The results show that CAPM is a hard problem. It is possible to get within 6% of the optimal policy, but policy performance is very dependent on user behaviour. Furthermore, adding more sensors to improve context inference can actually increase overall energy consumption.
Amigo: Proximity-Based Authentication of Mobile Devices BIBAFull-Text 253-270
  Alex Varshavsky; Adin Scannell; Anthony LaMarca; Eyal de Lara
Securing interactions between devices that do not know each other a priori is an important and challenging task. We present Amigo, a technique to authenticate co-located devices using knowledge of their shared radio environment as proof of physical proximity. We present evaluation results that show that our technique is robust against a range of passive and active attacks. The key advantages of our technique are that it does not require any additional hardware to be present on the devices beyond the radios that are already used for communication, it does not require user involvement to verify the validity of the authentication process, and it is not vulnerable to eavesdropping.

Activity Sensing

At the Flick of a Switch: Detecting and Classifying Unique Electrical Events on the Residential Power Line BIBAFull-Text 271-288
  Shwetak N. Patel; Thomas Robertson; Julie A. Kientz; Matthew S. Reynolds; Gregory D. Abowd
Activity sensing in the home has a variety of important applications, including healthcare, entertainment, home automation, energy monitoring and post-occupancy research studies. Many existing systems for detecting occupant activity require large numbers of sensors, invasive vision systems, or extensive installation procedures. We present an approach that uses a single plug-in sensor to detect a variety of electrical events throughout the home. This sensor detects the electrical noise on residential power lines created by the abrupt switching of electrical devices and the noise created by certain devices while in operation. We use machine learning techniques to recognize electrically noisy events such as turning on or off a particular light switch, a television set, or an electric stove. We tested our system in one home for several weeks and in five homes for one week each to evaluate the system performance over time and in different types of houses. Results indicate that we can learn and classify various electrical events with accuracies ranging from 85-90%.
Note: Nominated for the Best Paper Award
An 'Object-Use Fingerprint': The Use of Electronic Sensors for Human Identification BIBAFull-Text 289-303
  Mark R. Hodges; Martha E. Pollack
We describe an experiment in using sensor-based data to identify individuals as they perform a simple activity of daily living (making coffee). The goal is to determine whether people have regular and recognizable patterns of interaction with objects as they perform such activities. We describe the use of a machine-learning algorithm to induce decision-trees that classify interaction patterns according to the subject who exhibited them; we consider which features of the sensor data have the most effect on classification accuracy; and we consider ways of reducing the computational complexity introduced by the most important feature type. Although our experiment is preliminary, the results are encouraging: we are able to do identification with an overall accuracy rate of 97%, including correctly recognizing each individual in at least 9 of 10 trials.
Key Generation Based on Acceleration Data of Shaking Processes BIBAFull-Text 304-317
  Daniel Bichler; Guido Stromberg; Mario Huemer; Manuel Löw
Hard restrictions in computing power and energy consumption favour symmetric key methods to encrypt the communication in wireless body area networks which in term impose questions on effective and user-friendly unobtrusive ways for key distribution. In this paper, we present a novel approach to establish a secure connection between two devices by shaking them together. Instead of distributing or exchanging a key, the devices independently generate a key from the measured acceleration data by appropriate signal processing methods. Exhaustive practical experiments based on acceleration data gathered from real hardware prototypes have shown that in about 80% of the cases, a common key can be successfully generated. The average entropy of these generated keys exceed 13bits.

Case Studies

"Merolyn the Phone": A Study of Bluetooth Naming Practices (Nominated for the Best Paper Award) BIBAKFull-Text 318-335
  Tim Kindberg; Timothy Jones
This paper reports the results of an in-depth study of Bluetooth naming practices which took place in the UK in August 2006. There is a significant culture of giving Bluetooth names to mobile phones in the UK, and this paper's main contribution is to provide an account of those Bluetooth naming practices, putting them in their social, physical and intentional context. The paper also uncovers how users have appropriated the ways in which Bluetooth, with its relatively short range of about 10-100m, operates between their mobile phones as a partially embodied medium, making it a distinctive paradigm of socially and physically embedded communication.
Keywords: Bluetooth; electronic identity; naming; mobile phones
Why It's Worth the Hassle: The Value of In-Situ Studies When Designing Ubicomp BIBAKFull-Text 336-353
  Yvonne Rogers; Kay Connelly; Lenore Tedesco; William Hazlewood; Andrew Kurtz; Robert E. Hall; Josh Hursey; Tammy Toscos
How should Ubicomp technologies be evaluated? While lab studies are good at sensing aspects of human behavior and revealing usability problems, they are poor at capturing context of use. In-situ studies are good at demonstrating how people appropriate technologies in their intended setting, but are expensive and difficult to conduct. Here, we show how they can be used more productively in the design process. A mobile learning device was developed to support teams of students carrying out scientific inquiry in the field. An initial in-situ study showed it was not used in the way envisioned. A contextualized analysis led to a comprehensive understanding of the user experience, usability and context of use, leading to a substantial redesign. A second in-situ study showed a big improvement in device usability and collaborative learning. We discuss the findings and conclude how in-situ studies can play an important role in the design and evaluation of Ubicomp applications and user experiences.
Keywords: In-situ studies; design; evaluation; user experience; usability; mobile learning
Locating Family Values: A Field Trial of the Whereabouts Clock BIBAFull-Text 354-371
  Barry Brown; Alex S. Taylor; Shahram Izadi; Abigail Sellen; Joseph Jofish' Kaye; Rachel Eardley
We report the results of a long-term, multi-site field trial of a situated awareness device for families called the "Whereabouts Clock". The Clock displayed family members' current location as one of four privacy-preserving, deliberately coarse-grained categories (HOME, WORK , SCHOOL or ELSEWHERE) In use, the Clock supported not only family co-ordination but also more emotive aspects of family life such as reassurance, connectedness, identity and social touch. This emphasized aspects of family life frequently neglected in Ubicomp, such as the ways in which families' awareness of each others' activities contributes to a sense of a family's identity. We draw further on the results to differentiate between location as a technical aspect of awareness systems and what we characterize as "location-in-interaction". Location-in-interaction is revealed as an emotional, accountable and even moral part of family life.


Safeguarding Location Privacy in Wireless Ad-Hoc Networks BIBAFull-Text 372-390
  Tanzima Hashem; Lars Kulik
We present a novel algorithm that safeguards the location privacy of users accessing location-based services via mobile devices. Our technique exploits the capability of mobile devices to form wireless ad-hoc networks in order to hide a user's identity and position. Local ad-hoc networks enable us to separate an agent's request for location information, the query initiator, from the agent that actually requests this service on its behalf, the query requestor. Since a query initiator can select itself or one of the k-1 agents in its ad-hoc network as a query requestor, the query initiator remains k-anonymous. In addition, the location revealed to the location service provider is a rectangle instead of an exact coordinate. We develop an anonymous selection algorithm that selects a query requestor with near-uniform randomness, which is a key component to ensure anonymity in an ad-hoc network. Our experiments show that a system can ensure a high quality of service and maintain a high degree of privacy in terms of anonymity and obfuscation while accessing location-based services.
Haggle: Seamless Networking for Mobile Applications BIBAFull-Text 391-408
  Jing Su; James Scott; Pan Hui; Jon Crowcroft; Eyal de Lara; Christophe Diot; Ashvin Goel; Meng How Lim; Eben Upton
This paper presents Haggle, an architecture for mobile devices that enables seamless network connectivity and application functionality in dynamic mobile environments. Current applications must contain significant network binding and protocol logic, which makes them inflexible to the dynamic networking environments facing mobile devices. Haggle allows separating application logic from transport bindings so that applications can be communication agnostic. Internally, the Haggle framework provides a mechanism for late-binding interfaces, names, protocols, and resources for network communication. This separation allows applications to easily utilize multiple communication modes and methods across infrastructure and infrastructure-less environments. We provide a prototype implementation of the Haggle framework and evaluate it by demonstrating support for two existing legacy applications, email and web browsing. Haggle makes it possible for these applications to seamlessly utilize mobile networking opportunities both with and without infrastructure.
Exploiting Social Interactions in Mobile Systems BIBAFull-Text 409-428
  Andrew G. Miklas; Kiran K. Gollu; Kelvin K. W. Chan; Stefan Saroiu; Krishna P. Gummadi; Eyal de Lara
The popularity of handheld devices has created a flurry of research activity into new protocols and applications that can handle and exploit the defining characteristic of this new environment -- user mobility. In addition to mobility, another defining characteristic of mobile systems is user social interaction. This paper investigates how mobile systems could exploit people's social interactions to improve these systems' performance and query hit rate. For this, we build a trace-driven simulator that enables us to re-create the behavior of mobile systems in a social environment. We use our simulator to study three diverse mobile systems: DTN routing protocols, firewalls preventing a worm infection, and a mobile P2P file-sharing system. In each of these three cases, we find that mobile systems can benefit substantially from exploiting social information.

The Design Process

Rapidly Exploring Application Design Through Speed Dating BIBAKFull-Text 429-446
  Scott Davidoff; Min Kyung Lee; Anind K. Dey; John Zimmerman
While the user-centered design methods we bring from human-computer interaction to ubicomp help sketch ideas and refine prototypes, few tools or techniques help explore divergent design concepts, reflect on their merits, and come to a new understanding of design opportunities and ways to address them. We present Speed Dating, a design method for rapidly exploring application concepts and their interactions and contextual dimensions without requiring any technology implementation. Situated between sketching and prototyping, Speed Dating structures comparison of concepts, helping identify and understand contextual risk factors and develop approaches to address them. We illustrate how to use Speed Dating by applying it to our research on the smart home and dual-income families, and highlight our findings from using this method.
Keywords: Design methods; need validation; user enactments; Speed Dating Matrix; future breaching experiments; sketching; prototyping; reflection
Addressing Mobile Phone Diversity in Ubicomp Experience Development BIBAFull-Text 447-464
  Chris Greenhalgh; Steve Benford; Adam Drozd; Martin Flintham; Alastair Hampshire; Leif Oppermann; Keir Smith; Christoph von Tycowicz
Mobile phones are a widely-available class of device with supporting communications infrastructure which can be appropriated and exploited to support ubicomp experiences. However mobile phones vary hugely in their capabilities. We explore how a single dimension of phone application type embodies the critical trade-off between capability and availability, i.e. between what can be done and the fraction of potential participants' phones that can do this. We describe four different mobile phone ubicomp experiences that illustrate different points along this continuum (SMS, WAP/Web, and J2ME, Python and native applications) and the common software platform/toolkit, EQUIP2, that has been co-developed to support them. From this we propose four development strategies for addressing mobile phone diversity: prioritise support for server development (including web integration), migrate functionality between server(s) and handset(s), support flexible communication options, and use a loosely coupled (data-driven and component-based) software approach.
Sensor Networks or Smart Artifacts? An Exploration of Organizational Issues of an Industrial Health and Safety Monitoring System BIBAKFull-Text 465-482
  Gerd Kortuem; David Alford; Linden Ball; Jerry Busby; Nigel Davies; Christos Efstratiou; Joe Finney; Marian Iszatt White; Katharina Kinder
Industrial health and safety is an important yet largely unexplored application area of ubiquitous computing. In this paper we investigate the relationship between technology and organization in the context of a concrete industrial health and safety system. The system is designed to reduce the number of incidents of "vibration white finger" (VWF) at construction sites and uses wireless sensor nodes for monitoring workers' exposure to vibrations and testing of compliance with legal health and safety regulations. In particular we investigate the impact of this ubiquitous technology on the relationship between management and operatives, the formulation of health and safety rules and the risk perception and risk behavior of operatives. In addition, we contrast sensor-network inspired and smart artifact inspired compliance systems, and make the case that these technology models have a strong influence on the linkage between technology and organization.
Keywords: ubiquitous computing; sensor network; smart artifact; workplace support; occupational health and safety; safety culture; risk management; compliance architecture; organizational fit; privacy

Activity Sensing

A Long-Term Evaluation of Sensing Modalities for Activity Recognition BIBAFull-Text 483-500
  Beth Logan; Jennifer Healey; Matthai Philipose; Emmanuel Munguia Tapia; Stephen Intille
We study activity recognition using 104 hours of annotated data collected from a person living in an instrumented home. The home contained over 900 sensor inputs, including wired reed switches, current and water flow inputs, object and person motion detectors, and RFID tags. Our aim was to compare different sensor modalities on data that approached "real world" conditions, where the subject and annotator were unaffiliated with the authors. We found that 10 infra-red motion detectors outperformed the other sensors on many of the activities studied, especially those that were typically performed in the same location. However, several activities, in particular "eating" and "reading" were difficult to detect, and we lacked data to study many fine-grained activities. We characterize a number of issues important for designing activity detection systems that may not have been as evident in prior work when data was collected under more controlled conditions.
Cooperative Augmentation of Smart Objects with Projector-Camera Systems BIBAKFull-Text 501-518
  David Molyneaux; Hans Gellersen; Gerd Kortuem; Bernt Schiele
In this paper we present a new approach for cooperation between mobile smart objects and projector-camera systems to enable augmentation of the surface of objects with interactive projected displays. We investigate how a smart object's capability for self description and sensing can be used in cooperation with the vision capability of projector-camera systems to help locate, track and display information onto object surfaces in an unconstrained environment. Finally, we develop a framework that can be applied to distributed projector-camera systems, cope with varying levels of description knowledge and different sensors embedded in an object.
Keywords: Cooperative Augmentation; Smart Objects; Projector-Camera Systems