| Accurate activity recognition in a home setting | | BIBAK | Full-Text | 1-9 | |
| Tim van Kasteren; Athanasios Noulas; Gwenn Englebienne; Ben Kröse | |||
| A sensor system capable of automatically recognizing activities would allow
many potential ubiquitous applications. In this paper, we present an easy to
install sensor network and an accurate but inexpensive annotation method. A
recorded dataset consisting of 28 days of sensor data and its annotation is
described and made available to the community. Through a number of experiments
we show how the hidden Markov model and conditional random fields perform in
recognizing activities. We achieve a timeslice accuracy of 95.6% and a class
accuracy of 79.4%. Keywords: activity recognition, annotation, dataset, probabilistic models, sensor
networks | |||
| Discovery of activity patterns using topic models | | BIBAK | Full-Text | 10-19 | |
| Tâm Huynh; Mario Fritz; Bernt Schiele | |||
| In this work we propose a novel method to recognize daily routines as a
probabilistic combination of activity patterns. The use of topic models enables
the automatic discovery of such patterns in a user's daily routine. We report
experimental results that show the ability of the approach to model and
recognize daily routines without user annotation. Keywords: activity recognition, wearable computing | |||
| Dealing with sensor displacement in motion-based onbody activity recognition systems | | BIBAK | Full-Text | 20-29 | |
| Kai Kunze; Paul Lukowicz | |||
| We present a set of heuristics that significantly increase the robustness of
motion sensor-based activity recognition with respect to sensor displacement.
In this paper placement refers to the position within a single body part (e.g,
lower arm). We show how, within certain limits and with modest quality
degradation, motion sensor-based activity recognition can be implemented in a
displacement tolerant way. We first describe the physical principles that lead
to our heuristic. We then evaluate them first on a set of synthetic lower arm
motions which are well suited to illustrate the strengths and limits of our
approach, then on an extended modes of locomotion problem (sensors on the upper
leg) and finally on a set of exercises performed on various gym machines
(sensors placed on the lower arm). In this example our heuristic raises the
displaced recognition rate from 24% for a displaced accelerometer, which had
96% recognition when not displaced, to 82%. Keywords: fitness exercises, motion sensors, opportunistic activity recognition,
sensor displacement | |||
| Real world activity recognition with multiple goals | | BIBAK | Full-Text | 30-39 | |
| Derek Hao Hu; Sinno Jialin Pan; Vincent Wenchen Zheng; Nathan Nan Liu; Qiang Yang | |||
| Recognizing and understanding the activities of people from sensor readings
is an important task in ubiquitous computing. Activity recognition is also a
particularly difficult task because of the inherent uncertainty and complexity
of the data collected by the sensors. Many researchers have tackled this
problem in an overly simplistic setting by assuming that users often carry out
single activities one at a time or multiple activities consecutively, one after
another. However, so far there has been no formal exploration on the degree in
which humans perform concurrent or interleaving activities, and no thorough
study on how to detect multiple goals in a real world scenario. In this
article, we ask the fundamental questions of whether users often carry out
multiple concurrent and interleaving activities or single activities in their
daily life, and if so, whether such complex behavior can be detected accurately
using sensors. We define several classes of complexity levels under a goal
taxonomy that describe different granularities of activities, and relate the
recognition accuracy with different complexity levels or granularities. We
present a theoretical framework for recognizing multiple concurrent and
interleaving activities, and evaluate the framework in several real-world
ubiquitous computing environments. Keywords: activity recognition, concurrent activities, conditional random field,
interleaving activities | |||
| Improving the recognition of interleaved activities | | BIBAK | Full-Text | 40-43 | |
| Joseph Modayil; Tongxin Bai; Henry Kautz | |||
| We introduce Interleaved Hidden Markov Models for recognizing multitasked
activities. The model captures both inter-activity and intra-activity dynamics.
Although the state space is intractably large, we describe an approximation
that is both effective and efficient. This method significantly reduces the
error rate when compared with previously proposed methods. The algorithm is
suitable for mobile platforms where computational resources may be limited. Keywords: activity recognition, hidden Markov model, interleaved activities | |||
| Lifelogging memory appliance for people with episodic memory impairment | | BIBAK | Full-Text | 44-53 | |
| Matthew L. Lee; Anind K. Dey | |||
| Lifelogging technologies have the potential to provide memory cues for
people who struggle with episodic memory impairment (EMI). These memory cues
enable the recollection of significant experiences, which is important for
people with EMI to regain a sense of normalcy in their lives. However,
lifelogging technologies often collect an overwhelmingly large amount of data
to review. The best memory cues need to be extracted and presented in a way
that best supports episodic recollection. We describe the design of a new
lifelogging system that captures photos, ambient audio, and location
information and leverages both automated content/context analysis and the
expertise of family caregivers to facilitate the extraction and annotation of a
salient summary consisting of good cues from the lifelog. The system presents
the selected cues for review in a way that maximizes the opportunities for the
person with EMI to think deeply about these cues to trigger memory recollection
on his own without burdening the caregiver. We compare our system with another
review system that requires the caregiver to repeatedly guide the review
process. Our self-guided system resulted in better memory retention and imposed
a smaller burden on the caregiver whereas the caregiver-guided approach
provided more opportunities for caregiver interaction. Keywords: Alzheimer's disease, caregiver burden, information overload, lifelogging,
memory impairment | |||
| Flowers or a robot army?: encouraging awareness & activity with personal, mobile displays | | BIBAK | Full-Text | 54-63 | |
| Sunny Consolvo; Predrag Klasnja; David W. McDonald; Daniel Avrahami; Jon Froehlich; Louis LeGrand; Ryan Libby; Keith Mosher; James A. Landay | |||
| Personal, mobile displays, such as those on mobile phones, are ubiquitous,
yet for the most part, underutilized. We present results from a field
experiment that investigated the effectiveness of these displays as a means for
improving awareness of daily life (in our case, self-monitoring of physical
activity). Twenty-eight participants in three experimental conditions used our
UbiFit system for a period of three months in their day-to-day lives over the
winter holiday season. Our results show, for example, that participants who had
an awareness display were able to maintain their physical activity level (even
during the holidays), while the level of physical activity for participants who
did not have an awareness display dropped significantly. We discuss our results
and their general implications for the use of everyday mobile devices as
awareness displays. Keywords: ambient display, awareness, calm technology, field experiment, fitness,
glanceable display, mobile phone, personal mobile display, persuasive
technology, physical activity | |||
| Online everywhere: evolving mobile instant messaging practices | | BIBAK | Full-Text | 64-73 | |
| Donald J. Patterson; Christopher Baker; Xianghua Ding; Samuel J. Kaufman; Kah Liu; Andrew Zaldivar | |||
| In this paper we report on the results of a large scale user survey
investigating the status setting and interruption management behavior of mobile
instant messaging (IM) users with existing systems. The motivation for this
study was to inform the design of interface tools that support users by setting
contextually appropriate awareness messages. Our results demonstrate that many
desktop IM practices have been appropriated by mobile laptop users, but in the
face of increasingly situated computer usage and an "always online" culture,
several frictions are emerging between desktop and mobile practices. We find
that common assumptions about IM users and the established awareness cues are
failing and users are frequently embarrassed and interrupted with negative and
sometimes threatening consequences. Keywords: IM, awareness, instant messaging, location disclosure, mobile computing,
online status, presence, privacy | |||
| A quantitative investigation of inertial power harvesting for human-powered devices | | BIBAK | Full-Text | 74-83 | |
| Jaeseok Yun; Shwetak Patel; Matt Reynolds; Gregory Abowd | |||
| We present an empirical study of the long-term practicality of using human
motion to generate operating power for body-mounted consumer electronics and
health sensors. We have collected a large continuous acceleration dataset from
eight experimental subjects going about their normal daily routine for 3 days
each. Each subject is instrumented with a data collection apparatus that
simultaneously logs 3-axis, 80Hz acceleration data from six body locations. We
use this dataset to optimize a first-principles physical model of the commonly
used velocity damped resonant generator (VDRG) by selecting physical parameters
such as resonant frequency and damping coefficient to maximize harvested power.
Our results show that with reasonable assumptions on size, mass, placement, and
efficiency of VDRG harvesters, most body-mounted wireless sensors and even some
consumer electronics devices, may be powered continuously and indefinitely from
everyday motion. Keywords: human-powered devices, inertial power harvesting | |||
| It's in your eyes: towards context-awareness and mobile HCI using wearable EOG goggles | | BIBAK | Full-Text | 84-93 | |
| Andreas Bulling; Daniel Roggen; Gerhard Tröster | |||
| In this work we describe the design, implementation and evaluation of a
novel eye tracker for context-awareness and mobile HCI applications. In
contrast to common systems using video cameras, this compact device relies on
Electrooculography (EOG). It consists of goggles with dry electrodes integrated
into the frame and a small pocket-worn component with a DSP for real-time EOG
signal processing. The device is intended for wearable and standalone use: It
can store data locally for long-term recordings or stream processed EOG signals
to a remote device over Bluetooth. We describe how eye gestures can be
efficiently recognised from EOG signals for HCI purposes. In an experiment
conducted with 11 subjects playing a computer game we show that 8 eye gestures
of varying complexity can be continuously recognised with equal performance to
a state-of-the-art video-based system. Physical activity leads to artefacts in
the EOG signal. We describe how these artefacts can be removed using an
adaptive filtering scheme and characterise this approach on a 5-subject
dataset. In addition to explicit eye movements for HCI, we discuss how the
analysis of unconscious eye movements may eventually allow to deduce
information on user activity and context not available with current sensing
modalities. Keywords: context-awareness, electrooculography (EOG), eye gestures, eye tracking,
human-computer interaction (HCI), wearable computing | |||
| Wideband powerline positioning for indoor localization | | BIBAK | Full-Text | 94-103 | |
| Erich P. Stuntebeck; Shwetak N. Patel; Thomas Robertson; Matthew S. Reynolds; Gregory D. Abowd | |||
| Fingerprinting techniques for indoor localization have been widely explored.
A particular approach by Patel et al. suggested leveraging of the residential
powerline as the signaling mechanism for a domestic location capability. In
this paper, we critically examine that initial work, called powerline
positioning (PLP). We find the proposed technique lacking in temporal
stability, requiring frequent and undesired recalibration in some environments.
We also determine that there is no a priori method to determine a pair of
signaling frequencies that will reliably work in any space. We propose a
wideband approach to PLP (WPLP) that injects up to 44 different frequencies
into the powerline. We show that this WPLP approach improves upon overall
positioning accuracy, demonstrates greatly improved temporal stability and has
the added advantage of working in commercial indoor spaces. Keywords: context awareness, fingerprinting, localization, location tracking | |||
| CILoS: a CDMA indoor localization system | | BIBAK | Full-Text | 104-113 | |
| Waqas ur Rehman; Eyal de Lara; Stefan Saroiu | |||
| CILoS is an indoor localization system based on CDMA mobile phone signal
fingerprinting. CDMA networks vary their transmission power to accommodate
fluctuations in network load. This affects signal intensity and therefore
limits the practicality of traditional fingerprinting approaches based on
receiver signal strength (RSSI) measurements. Instead, CILoS uses fingerprints
of signal delay that are robust to cell resizing. We demonstrate that CILoS
achieves a median accuracy of 5 meters, and compares favourably to RSSI
fingerprinting systems. We highlight the significance of wide fingerprints,
constructed through scanning multiple channels, for achieving high localization
accuracy. We also show that our system can accurately differentiate between
floors of a multifloor building. Keywords: localization system, location, radio fingerprinting | |||
| Pedestrian localisation for indoor environments | | BIBAK | Full-Text | 114-123 | |
| Oliver Woodman; Robert Harle | |||
| Location information is an important source of context for ubiquitous
computing systems. This paper looks at how a foot-mounted inertial unit, a
detailed building model, and a particle filter can be combined to provide
absolute positioning, despite the presence of drift in the inertial unit and
without knowledge of the user's initial location. We show how to handle
multiple floors and stairways, how to handle symmetry in the environment, and
how to initialise the localisation algorithm using WiFi signal strength to
reduce initial complexity.
We evaluate the entire system experimentally, using an independent tracking system for ground truth. Our results show that we can track a user throughout a 8725 m{sup:2} building spanning three floors to within 0.5m 75% of the time, and to within 0.73 m 95% of the time. Keywords: inertial tracking, localisation, particle filters | |||
| Localization in mobile ad hoc networks using cumulative route information | | BIBAK | Full-Text | 124-133 | |
| Jahyoung Koo; Jiyoung Yi; Hojung Cha | |||
| Discovering the location of the mobile nodes carried by people is important
issue for many sensor applications. Several localization techniques have been
proposed, but human mobility patterns and collaboration between mobile nodes
have been seldom considered. In this paper, we propose a mobile node
localization system based on collaboration and route information that
characterizes human mobility. To validate the feasibility of our approach, the
proposed system is implemented and experiments are conducted on real routes and
to evaluate various scenarios, simulation experiment was also conducted. Keywords: collaboration, mobile node localization, wireless sensor networks | |||
| Interactionist AI and the promise of ubicomp, or, how to put your box in the world without putting the world in your box | | BIBAK | Full-Text | 134-143 | |
| Lucian Leahu; Phoebe Sengers; Michael Mateas | |||
| In many ways, the central problem of ubiquitous computing -- how
computational systems can make sense of and respond sensibly to a complex,
dynamic environment laden with human meaning -- is identical to that of
Artificial Intelligence (AI). Indeed, some of the central challenges that
ubicomp currently faces in moving from prototypes that work in restricted
environments to the complexity of real-world environments -- e.g. difficulties
in scalability, integration, and fully formalizing context -- echo some of the
major issues that have challenged AI researchers over the history of their
field. In this paper, we explore a key moment in AI's history where researchers
grappled directly with these issues, resulting in a variety of novel technical
solutions within AI. We critically reflect on six strategies from this history
to suggest technical solutions for how to approach the challenge of building
real-world, usable solutions in ubicomp today. Keywords: AI-completeness, interactionist AI, reflective HCI | |||
| On using existing time-use study data for ubiquitous computing applications | | BIBAK | Full-Text | 144-153 | |
| Kurt Partridge; Philippe Golle | |||
| Governments and commercial institutions have conducted detailed time-use
studies for several decades. In these studies, participants give a detailed
record of their activities, locations, and other data over a day, week, or
longer period. These studies are particularly valuable for the ubicomp
community because of the large number of participants (often the tens of
thousands), and because of their public availability. In this paper, we show
how to use the data from these studies to provide validated and cheap (although
noisy) classifiers, baseline metrics, and other benefits for activity inference
applications. Keywords: activity inference, diary studies, evaluation methodologies, mobile
computing, time-use studies, ubiquitous computing | |||
| Using wearable sensors and real time inference to understand human recall of routine activities | | BIBAK | Full-Text | 154-163 | |
| Predrag Klasnja; Beverly L. Harrison; Louis LeGrand; Anthony LaMarca; Jon Froehlich; Scott E. Hudson | |||
| Users' ability to accurately recall frequent, habitual activities is
fundamental to a number of disciplines, from health sciences to machine
learning. However, few, if any, studies exist that have assessed optimal
sampling strategies for in situ self-reports. In addition, few technologies
exist that facilitate benchmarking self-report accuracy for routine activities.
We report on a study investigating the effect of sampling frequency of
self-reports of two routine activities (sitting and walking) on recall accuracy
and annoyance. We used a novel wearable sensor platform that runs a real time
activity inference engine to collect in situ ground truth. Our results suggest
that a sampling frequency of five to eight times per day may yield an optimal
balance of recall and annoyance. Additionally, requesting self-reports at
regular, predetermined times increases accuracy while minimizing perceived
annoyance since it allows participants to anticipate these requests. We discuss
our results and their implications for future studies. Keywords: ESM, empirical evaluation, experience sampling method, recall accuracy,
self-reports, survey frequency, user study | |||
| Using visualizations to increase compliance in experience sampling | | BIBAK | Full-Text | 164-167 | |
| Gary Hsieh; Ian Li; Anind Dey; Jodi Forlizzi; Scott E. Hudson | |||
| Experience sampling method (or ESM) is a common data collection method to
understand user behavior and to evaluate ubiquitous computing technologies.
However, ESM studies often demand too much time and commitment from
participants, which leads to attrition and low compliance among participants.
We introduce a new approach called experience sampling with feedback or
ES+feedback that improves compliance by giving feedback to participants through
various visualizations. Providing feedback to users makes the information
personally relevant and increases the value of the study to participants, which
increases their compliance. Our exploratory study shows that ES+feedback
increases the compliance rate by 23%. Keywords: empirical studies, experience sampling, visualizations | |||
| Towards the automated social analysis of situated speech data | | BIBAK | Full-Text | 168-171 | |
| Danny Wyatt; Jeff Bilmes; Tanzeem Choudhury; James A. Kitts | |||
| We present an automated approach for studying fine-grained details of social
interaction and relationships. Specifically, we analyze the conversational
characteristics of a group of 24 individuals over a six-month period, explore
the relationship between conversational dynamics and network position, and
identify behavioral correlates of tie strengths within a network. The ability
to study conversational dynamics and social networks over long time scales, and
to investigate their interplay with rigor, objectivity, and transparency will
complement the traditional methods for scientific inquiry into social dynamics.
They may also enable socially aware ubiquitous computing systems that are
cognizant of and responsive to the user's engagement with her social
environment. Keywords: machine learning, social network analysis, wearable computing | |||
| Design and implementation of a secure wireless mote-based medical sensor network | | BIBAK | Full-Text | 172-181 | |
| Kriangsiri Malasri; Lan Wang | |||
| A medical sensor network can wirelessly monitor vital signs of humans,
making it useful for long-term health care without sacrificing patient comfort
and mobility. For such a network to be viable, its design must protect data
privacy and authenticity given that medical data are highly sensitive. We
identify the unique security challenges facing such a sensor network and
propose a set of resource-efficient mechanisms to address these challenges. Our
solution includes (1) a novel two-tier scheme for verifying the authenticity of
patient data; (2) an ECC-based secure key exchange protocol to set up shared
keys between sensor nodes and base stations; and (3) symmetric
encryption/decryption for protecting data confidentiality and integrity. We
have implemented the proposed mechanisms on a wireless mote platform and our
results confirm their feasibility. Keywords: authenticity, health monitoring, privacy, sensor network | |||
| An empirical investigation of concerns of everyday tracking and recording technologies | | BIBAK | Full-Text | 182-191 | |
| David H. Nguyen; Alfred Kobsa; Gillian R. Hayes | |||
| This paper presents an exploration and analysis of attitudes towards
everyday tracking and recording technologies (e. g., credit cards, store
loyalty cards, store video cameras). Interview participants reported being
highly concerned with information privacy. At the same time, however, they also
reported being significantly less concerned regarding the use of everyday
technologies that have the capabilities to collect, process, and disseminate
personal information. We present results from this study that both identify and
begin to explain this discrepancy. Keywords: everyday technologies, privacy, recording, retail, tracking, user study | |||
| Reflecting on the invisible: understanding end-user perceptions of ubiquitous computing | | BIBAK | Full-Text | 192-201 | |
| Erika Shehan Poole; Christopher A. Le Dantec; James R. Eagan; W. Keith Edwards | |||
| How can designers of ubiquitous computing technologies ensure that they
understand the non-functional needs, values, and expectations of end-users? In
this paper, we use a qualitative method from public policy to elicit reflective
feedback from end-users about technologies that they may not yet have used nor
fully comprehend. Our study uncovers information about end-user perceptions of
RFID, including a range of "folk theories" held by the public about this
technology, and their associations of it with certain social groups and values.
We argue that these perceptions can limit technological adoption, and conclude
with a discussion of challenges for the design and deployment of ubiquitous
computing systems. Keywords: evaluation techniques, folk theories, qualitative methods, social
implications, technology adoption | |||
| Protecting your daily in-home activity information from a wireless snooping attack | | BIBAK | Full-Text | 202-211 | |
| Vijay Srinivasan; John Stankovic; Kamin Whitehouse | |||
| In this paper, we first present a new privacy leak in residential wireless
ubiquitous computing systems, and then we propose guidelines for designing
future systems to prevent this problem. We show that we can observe private
activities in the home such as cooking, showering, toileting, and sleeping by
eavesdropping on the wireless transmissions of sensors in a home, even when all
of the transmissions are encrypted. We call this the Fingerprint and
Timing-based Snooping (FATS) attack. This attack can already be carried out on
millions of homes today, and may become more important as ubiquitous computing
environments such as smart homes and assisted living facilities become more
prevalent. In this paper, we demonstrate and evaluate the FATS attack on eight
different homes containing wireless sensors. We also propose and evaluate a set
of privacy preserving design guidelines for future wireless ubiquitous systems
and show how these guidelines can be used in a hybrid fashion to prevent
against the FATS attack with low implementation costs. Keywords: activity monitoring, side channel privacy attacks, wireless fingerprinting | |||
| MobiRate: making mobile raters stick to their word | | BIBAK | Full-Text | 212-221 | |
| Daniele Quercia; Stephen Hailes; Licia Capra | |||
| To share services, portable devices may need to locate reputable in-range
providers and, to do so, they may exchange ratings with each other. However,
providers may well tweak ratings to their own advantage. That is why we have
designed a new decentralized mechanism (dubbed MobiRate) with which portable
devices store ratings in (local) tamper-evident tables and check the integrity
of those tables through a gossiping protocol. We evaluate the extent to which
MobiRate reduces the impact of tampered ratings and consequently locates
reputable service providers. We do so using real mobility and social network
data. We also assess computational and communication costs of MobiRate on
mobile phones. Keywords: distributed reputation (trust) systems, mobile systems | |||
| The heterogeneous home | | BIBAK | Full-Text | 222-231 | |
| Ryan Aipperspach; Ben Hooker; Allison Woodruff | |||
| Due to several recent trends, the domestic environment has become more
homogeneous and undifferentiated. Drawing on concepts from environmental
psychology, we critique these trends. We propose heterogeneity as a new
framework for domestic design, and we present design sketches that illustrate
how ubiquitous computing technologies can interact with the domestic
environment to create a more varied and restorative environment. This work
speaks to a number of core issues in ubiquitous computing, such as how the
increased presence of devices impacts quality of life, the desirability or
undesirability of ubiquitous temporal and spatial availability of devices, and
the advantages and disadvantages of device convergence ("all-in-one" devices)
versus device proliferation (single application devices). Keywords: architecture, domestic technology, interaction design | |||
| Plastic: a metaphor for integrated technologies | | BIBAK | Full-Text | 232-241 | |
| Tye Rattenbury; Dawn Nafus; Ken Anderson | |||
| Ubiquitous computing research has recently focused on 'busyness' in American
households. While these projects have generated important insights into
coordination and communication, we think they overlook the more spontaneous and
opportunistic activities that surround and support the scheduled ones. Using
data from our mixed-methods study of notebook and ultra-mobile PC use, we argue
for a different perspective based on a metaphor of 'plastic'. 'Plastic'
captures the way technologies, specifically computers, have integrated into the
heterogeneous rhythms of daily life. Plastic technologies harmonize with and
support daily life by filling opportunistic gaps, shrinking and expanding until
interrupted, not demanding conscious coordination, supporting multitasking, and
by deferring to external contingencies. Keywords: attention, busyness, personal computers, plastic, temporality | |||
| Getting to green: understanding resource consumption in the home | | BIBAK | Full-Text | 242-251 | |
| Marshini Chetty; David Tran; Rebecca E. Grinter | |||
| Rising global energy demands, increasing costs and limited natural resources
mean that householders are more conscious about managing their domestic
resource consumption. Yet, the question of what tools Ubicomp researchers can
create for residential resource management remains open. To begin to address
this omission, we present a qualitative study of 15 households and their
current management practices around the water, electricity and natural gas
systems in the home. We find that in-the-moment resource consumption is mostly
invisible to householders and that they desire more real-time information to
help them save money, keep their homes comfortable and be environmentally
friendly. Designing for domestic sustainability therefore turns on improving
the visibility of resource production and consumption costs as well as
supporting both individuals and collectives in behavior change. Domestic
sustainability also highlights the caveat of potentially creating a green
divide by making resource management available only to those who can afford the
technologies to support being green. Finally, we suggest that the Ubicomp
community can contribute to the domestic and broader sustainability agenda by
incorporating green values in designs and highlight the challenge of collecting
data on being green. Keywords: domestic conservation, residential resource consumption, sustainability | |||
| Designing sociable IT for public use | | BIBAK | Full-Text | 252-261 | |
| Steinar Kristoffersen; Ingunn Bratteberg | |||
| Service providers increasingly use self-service systems, such as kiosk and
automata that offer faster and more flexible service. Most of us are familiar
with appliances for buying and validating tickets, purchasing soft drinks or
getting the newspaper. We book tables in restaurants and hire cars using hotel
lobby kiosks. Unfortunately, many such systems confuse and annoy their users.
Thus, information technology design for the public space poses distinct
challenges. Yet, it is relatively unmapped within our field. Based on an
ethnographic study of the purchase and validation of ticketless travel for an
airport train, this paper shows how such systems need an extended framework of
usability principles, which goes beyond well-known interaction design
guidelines. Keywords: design guidelines, ethnography, public IT, usability | |||
| Mixed-initiative conflict resolution for context-aware applications | | BIBAK | Full-Text | 262-271 | |
| Choonsung Shin; Anind K. Dey; Woontack Woo | |||
| A number of technologies have contributed to automatically resolving
resource conflicts between multiple users in a smart space. However, such
systems eliminate the users' ability to perform this conflict resolution by
themselves, which they actually prefer to do in certain circumstances. Since
both resolution approaches have their merits, we propose a mixed-initiative
conflict resolution system, which combines automatic conflict resolution with
mediated, or user-driven, resolution by exploiting contextual information in
context-aware applications. An evaluation of our system found that users prefer
to use a mediated resolution approach when their preferences about outcome are
very different from others', but have no preferred method when their
preferences about outcome are similar to others'. Keywords: conflict resolution, context-aware computing, mixed-initiative, smart space | |||
| A context-aware patient safety system for the operating room | | BIBAK | Full-Text | 272-281 | |
| Jakob E. Bardram; Niels Nørskov | |||
| Most context-aware systems have been designed for non-safety-critical
environments such as offices, museums, and university campuses. This paper
argues that context-awareness can be used for safety-critical systems too. But
since the consequences of errors or failures in safety-critical systems are
potentially severe, we should have a high degree of confidence in these
systems. We present the design, implementation, and evaluation of a
context-aware patient safety and information system (CAPSIS) designed for use
during surgery. Specifically, our study indicates that CAPSIS could improve
patient safety in the operating room. More generally, the paper suggests that
context-aware technologies offer a promising step forward in the design of
safety-critical systems. Keywords: CAPSIS, context-aware computing, operating room, pervasive healthcare,
safety-critical systems | |||
| Deploy spontaneously: supporting end-users in building and enhancing a smart home | | BIBAK | Full-Text | 282-291 | |
| Fahim Kawsar; Tatsuo Nakajima; Kaori Fujinami | |||
| This paper explores system issues for involving end users in constructing
and enhancing a smart home. In support of this involvement we present an
infrastructure and a tangible deployment tool. Active participation of users is
essential in a domestic environment as it offers simplicity, greater
user-centric control, lower deployment costs and better support for
personalization. Our proposed infrastructure provides the foundation for end
user deployment utilizing a loosely coupled framework to represent an artefact
and its augmented functionalities. Pervasive applications are built
independently and are expressed as a collection of functional tasks. A runtime
component, FedNet maps these tasks to corresponding service provider artefacts.
The tangible deployment tool uses FedNet and allows end users to deploy and
control artefacts and applications only by manipulating RFID cards. Primary
advantages of our approach are two-fold. Firstly, it allows end users to deploy
ubicomp systems easily in a Do-it-Yourself fashion. Secondly, it allows
developers to write applications and to build augmented artefacts in a generic
way regardless of the constraints of the target environment. We describe an
implemented prototype and illustrate its feasibility in a real life deployment
session by the end users. Our study shows that the end users might be involved
in deploying future ubicomp systems if appropriate tools and supporting
infrastructure are provided. Keywords: augmented artefact, end user deployment, pervasive application, system
infrastructure | |||
| Schema matching for context-aware computing | | BIBAK | Full-Text | 292-301 | |
| Wenwei Xue; Hungkeng Pung; Paulito P. Palmes; Tao Gu | |||
| Context-aware computing is a key paradigm of ubiquitous computing in which
applications automatically adapt their operations to dynamic context data from
multiple sources. Managing a number of distributed sources, a middleware that
facilitates the development of context-aware applications must provide a
uniform view of all these sources to the applications. Local schemas of context
data from individual sources need to be matched into a set of global schemas in
the middleware, upon which applications can issue context queries to acquire
data. In this paper, we study this problem of schema matching for context-aware
computing. We propose a multi-criteria algorithm to determine candidate
attribute matches between two schemas. The algorithm adaptively adjusts the
priorities of different criteria based on previous matching results to improve
the efficiency and accuracy of succeeding operations. We further develop an
algorithm to categorize a new local schema into one of the global schemas
whenever possible via a shared attribute dictionary. Our results based on
schemas from real-world websites demonstrate the good matching accuracy
achieved by our algorithms. Keywords: context attributes, context awareness, context schemas, middleware, schema
matching, ubiquitous computing | |||
| The potential for location-aware power management | | BIBAK | Full-Text | 302-311 | |
| R. K. Harle; A. Hopper | |||
| This paper explores the use of location-awareness to dynamically optimise
the energy consumption of an office. It makes use of high-accuracy location
data collected over 60 days randomly selected from a year in a commercial
environment to evaluate the potential for energy savings and to motivate
techniques that might be used.
The results suggest that the energy expended on lighting and fast-response systems could have been cut by 50%; that 75.8% of the average user's working day was spent in their office; and that around 140Wh per PC per day could have been saved, compared to a policy that had machines on for the entirety of the working day. We also find inconsistent office usage that would make optimising slow response systems much harder. Keywords: context-aware, energy efficiency, location-aware, power management | |||
| Understanding mobility based on GPS data | | BIBAK | Full-Text | 312-321 | |
| Yu Zheng; Quannan Li; Yukun Chen; Xing Xie; Wei-Ying Ma | |||
| Both recognizing human behavior and understanding a user's mobility from
sensor data are critical issues in ubiquitous computing systems. As a kind of
user behavior, the transportation modes, such as walking, driving, etc., that a
user takes, can enrich the user's mobility with informative knowledge and
provide pervasive computing systems with more context information. In this
paper, we propose an approach based on supervised learning to infer people's
motion modes from their GPS logs. The contribution of this work lies in the
following two aspects. On one hand, we identify a set of sophisticated
features, which are more robust to traffic condition than those other
researchers ever used. On the other hand, we propose a graph-based
post-processing algorithm to further improve the inference performance. This
algorithm considers both the commonsense constraint of real world and typical
user behavior based on location in a probabilistic manner. Using the GPS logs
collected by 65 people over a period of 10 months, we evaluated our approach
via a set of experiments. As a result, based on the change point-based
segmentation method and Decision Tree-based inference model, the new features
brought an eight percent improvement in inference accuracy over previous
result, and the graph-based post-processing achieve a further four percent
enhancement. Keywords: GPS, GeoLife, infer transportation mode, machine learning, recognize human
behavior | |||
| Navigate like a cabbie: probabilistic reasoning from observed context-aware behavior | | BIBAK | Full-Text | 322-331 | |
| Brian D. Ziebart; Andrew L. Maas; Anind K. Dey; J. Andrew Bagnell | |||
| We present PROCAB, an efficient method for Probabilistically Reasoning from
Observed Context-Aware Behavior. It models the context-dependent utilities and
underlying reasons that people take different actions. The model generalizes to
unseen situations and scales to incorporate rich contextual information. We
train our model using the route preferences of 25 taxi drivers demonstrated in
over 100,000 miles of collected data, and demonstrate the performance of our
model by inferring: (1) decision at next intersection, (2) route to known
destination, and (3) destination given partially traveled route. Keywords: decision modeling, route prediction, vehicle navigation | |||
| Accessible contextual information for urban orientation | | BIBAK | Full-Text | 332-335 | |
| Jason Stewart; Sara Bauman; Michelle Escobar; Jakob Hilden; Kumud Bihani; Mark W. Newman | |||
| We present Talking Points, an urban orientation system based on the idea
that an individual's walking journey can be enhanced by providing contextual
information about points of interest (POIs) along their route. Our formative
research revealed numerous ways to provide serendipitous and task-critical
information for both sighted and visually impaired users as they navigate
through an urban environment on foot. Based on this, we developed a prototype
system comprised of the following: an unobtrusive mobile device to present the
user with contextual information; a socially maintained online database
containing information about POIs; software that is accessible via both a
graphical and a speech user interface; and location "tags" to be detected by
the unobtrusive device. This socially maintained urban orientation and
contextual information system offers relevant, dynamic, and up-to-date
information, a combination which may not otherwise be accessible. Keywords: accessibility, blind, contextual information system, mobile computing, urban
orientation | |||
| Enhanced shopping: a dynamic map in a retail store | | BIBAK | Full-Text | 336-339 | |
| Alexander Meschtscherjakov; Wolfgang Reitberger; Michael Lankes; Manfred Tscheligi | |||
| This article investigates the prototypical implementation of a dynamic map
of a retail store and the results of an empirical study in the shopping
environment. Due to the distinct characteristics of the context of shopping
(e.g. openness to the public, preexisting technologies), this context is
particularly fruitful for UbiComp technologies. The prototype consists of a
display showing an enhanced store map, which combines the dynamic visualization
of customer activity (e.g. hot-spots, sales ranks) with conventional map
elements (e.g. product locations, promotions). The results of our three-day
in-situ study indicate the relevance and the usefulness of UbiComp technologies
for shopping environments. Keywords: ambient display, dynamic map, field study, retail store, shopping
environment, ubiquitous computing | |||
| Spyn: augmenting knitting to support storytelling and reflection | | BIBAK | Full-Text | 340-349 | |
| Daniela K. Rosner; Kimiko Ryokai | |||
| Ubicomp research has spurred the exploration of more "natural" or
"invisible" interfaces that can be seamlessly embedded into their environment.
In this paper, we discuss the role such technology can play in augmenting
existing creative practice to enhance the sharing of the handcraft process. We
present the design and implementation of Spyn, a system for knitters to record,
playback, and share information involved in the creation of their hand-knit
artifacts. Guided by a formative study of knitting practices, we designed Spyn
to capture information while a person knits and allow for the subsequent
retrieval of the information using the knit artifact. Spyn uses computer vision
techniques in combination with patterns of infrared ink printed on yarn to
correlate locations in knit fabric with messages recorded during the knitting
process. Rather than seeking to improve the speed or accuracy of the knitter,
we designed Spyn to enrich the knitter's craft while preserving the look and
feel of the knit artifact. Keywords: annotation, calm technology, communication, craft, handmade, process,
tangible | |||
| Picture this!: film assembly using toy gestures | | BIBAK | Full-Text | 350-359 | |
| Cati Vaucelle; Hiroshi Ishii | |||
| We present Picture This! a new input device embedded in children's toys for
video composition. It consists of a new form of interaction for children's
capturing of storytelling with physical artifacts. It functions as a video and
storytelling performance system in that children craft videos with and about
character toys as the system analyzes their gestures and play patterns.
Children's favorite props alternate between characters and cameramen in a film.
As they play with the toys to act out a story, they conduct film assembly. We
position our work as ubiquitous computing that supports children's tangible
interaction with digital materials. During user testing, we observed children
ages 4 to 10 playing with Picture This!. We assess to what extent gesture
interaction with objects for video editing allows children to explore visual
perspectives in storytelling. A new genre of Gesture Object Interfaces as
exemplified by Picture This relies on the analysis of gestures coupled with
objects to represent bits. Keywords: children, gesture object interfaces, play, storytelling, video | |||
| Bookisheet: bendable device for browsing content using the metaphor of leafing through the pages | | BIBAK | Full-Text | 360-369 | |
| Jun-ichiro Watanabe; Arito Mochizuki; Youichi Horry | |||
| We have developed an interface for browsing content that uses the metaphor
of turning the pages of a book. Using our "Bookisheet" interface, which
consists of two thin plastic sheets and bend sensors, a user can easily scroll
digital content such as photos by bending one side of the sheet or the other.
This action provides the tangible and pleasant sense of turning pages in a
book. Bookisheet can be used not only as an interface for conventional
information terminals but also as one for flexible displays. Keywords: book metaphor, content browsing, flexible display, navigation, tangible user
interface | |||
| Living with tableau machine: a longitudinal investigation of a curious domestic intelligence | | BIBAK | Full-Text | 370-379 | |
| Zachary Pousman; Mario Romero; Adam Smith; Michael Mateas | |||
| We present a longitudinal investigation of Tableau Machine, an intelligent
entity that interprets and reflects the lives of occupants in the home. We
created Tableau Machine (TM) to explore the parts of home life that are
unrelated to accomplishing tasks. Task support for "smart homes" has inspired
many researchers in the community. We consider design for experience, an
orthogonal dimension to task-centric home life. TM produces abstract
visualizations on a large LCD every few minutes, driven by a set of four
overhead cameras that capture a sense of the social life of a domestic space.
The openness and ambiguity of TM allow for a cycle of co-interpretation with
householders. We report on three longitudinal deployments of TM for a period of
six weeks. Participant families engaged with TM at the outset to understand how
their behaviors were influencing the machine, and, while TM remained puzzling,
householders interacted richly with TM and its images. We extract some key
design implications for an experience-focused smart home. Keywords: activity characterization, ambient intelligence, casual information
visualization, evaluation techniques, information visualization, interactive
art, sensors | |||
| Who will be the customer?: a social robot that anticipates people's behavior from their trajectories | | BIBAK | Full-Text | 380-389 | |
| Takayuki Kanda; Dylan F. Glas; Masahiro Shiomi; Hiroshi Ishiguro; Norihiro Hagita | |||
| For a robot providing services to people in a public space such as a train
station or a shopping mall, it is important to distinguish potential customers,
such as window-shoppers, from other people, such as busy commuters. In this
paper, we present a series of techniques for anticipating people's behavior in
a public space, mainly based on the analysis of accumulated trajectories, and
we demonstrate the use of these techniques in a social robot. We placed a
ubiquitous sensor network consisting of six laser range finders in a shopping
arcade. The system tracks people's positions as well as their local behaviors
such as fast walking, idle walking, or stopping. We accumulated people's
trajectories for a week, applying a clustering technique to the accumulated
trajectories to extract information about the use of space and people's typical
global behaviors. This information enables the robot to target its services to
people who are walking idly or stopping. The robot anticipates both the areas
in which people are likely to perform these behaviors, and also the probable
local behaviors of individuals a few seconds in the future. In a field
experiment we demonstrate that this system enables the robot to serve people
efficiently. Keywords: behavior anticipation, human-robot interaction | |||