Kent Larson

Activity Recognition in the Home Using Simple and Ubiquitous Sensors

In this work, a system for recognizing activities in the home setting using a set of small and simple state-change sensors is introduced. The sensors are designed to be “tape on and forget” devices that can be quickly and ubiquitously installed in home environments. The proposed sensing system presents an alternative to sensors that are sometimes perceived as invasive, such as cameras and microphones. Unlike prior work, the system has been deployed in multiple residential environments with non-researcher occupants. Preliminary results on a small dataset show that it is possible to recognize activities of interest to medical professionals such as toileting, bathing, and grooming with detection accuracies ranging from 25% to 89% depending on the evaluation criteria used.

Real-Time Recognition of Physical Activities and Their Intensities Using Wireless Accelerometers and a Heart Rate Monitor

In this paper, we present a real-time algorithm for automatic recognition of not only physical activities, but also, in some cases, their intensities, using five triaxial wireless accelerometers and a wireless heart rate monitor. The algorithm has been evaluated using datasets consisting of 30 physical gymnasium activities collected from a total of 21 people at two different labs. On these activities, we have obtained a recognition accuracy performance of 94.6% using subject-dependent training and 56.3% using subject-independent training. The addition of heart rate data improves subject-dependent recognition accuracy only by 1.2% and subject-independent recognition only by 2.1%. When recognizing activity type without differentiating intensity levels, we obtain a subject-independent performance of 80.6%. We discuss why heart rate data has such little discriminatory power.

Using a live-in laboratory for ubiquitous computing research

Ubiquitous computing researchers are increasingly turning to sensor-enabled “living laboratories” for the study of people and technologies in settings more natural than a typical laboratory. We describe the design and operation of the PlaceLab, a new live-in laboratory for the study of ubiquitous technologies in home settings. Volunteer research participants individually live in the PlaceLab for days or weeks at a time, treating it as a temporary home. Meanwhile, sensing devices integrated into the fabric of the architecture record a detailed description of their activities. The facility generates sensor and observational datasets that can be used for research in ubiquitous computing and other fields where domestic contexts impact behavior. We describe some of our experiences constructing and operating the living laboratory, and we detail a recently generated sample dataset, available online to researchers.

Adding GPS-Control to Traditional Thermostats: An Exploration of Potential Energy Savings and Design Challenges

Although manual and programmable home thermostats can save energy when used properly, studies have shown that over 40% of U.S. homes may not use energy-saving temperature setbacks when homes are unoccupied. We propose a system for augmenting these thermostats using just-in-time heating and cooling based on travel-to-home distance obtained from location-aware mobile phones. Analyzing GPS travel data from 8 participants (8-12 weeks each) and heating and cooling characteristics from 5 homes, we report results of running computer simulations estimating potential energy savings from such a device. Using a GPS-enabled thermostat might lead to savings of as much as 7% for some households that do not regularly use the temperature setback afforded by manual and programmable thermostats. Significantly, these savings could be obtained without requiring any change in occupant behavior or comfort level, and the technology could be implemented affordably by exploiting the ubiquity of mobile phones. Additional savings may be possible with modest context-sensitive prompting. We report on design considerations identified during a pilot test of a fully-functional implementation of the system.

Tools for Studying Behavior and Technology in Natural Settings

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.

The design of a portable kit of wireless sensors for naturalistic data collection

In this paper, we introduce MITes, a flexible kit of wireless sensing devices for pervasive computing research in natural settings. The sensors have been optimized for ease of use, ease of installation, affordability, and robustness to environmental conditions in complex spaces such as homes. The kit includes six environmental sensors: movement, movement tuned for object-usage-detection, light, temperature, proximity, and current sensing in electric appliances. The kit also includes five wearable sensors: onbody acceleration, heart rate, ultra-violet radiation exposure, RFID reader wristband, and location beacons. The sensors can be used simultaneously with a single receiver in the same environment. This paper describes our design goals and results of the evaluation of some of the sensors and their performance characteristics. Also described is how the kit is being used for acquisition of data in non-laboratory settings where real-time multi-modal sensor information is acquired simultaneously from several sensors worn on the body and up to several hundred sensors distributed in an environment.

Embedding behavior modification strategies into a consumer electronic device: a case study

Ubiquitous computing technologies create new opportunities for preventive healthcare researchers to deploy behavior modification strategies outside of clinical settings. In this paper, we describe how strategies for motivating behavior change might be embedded within usage patterns of a typical electronic device. This interaction model differs substantially from prior approaches to behavioral modification such as CD-ROMs: sensor-enabled technology can drive interventions that are timelier, tailored, subtle, and even fun. To explore these ideas, we developed a prototype system namedViTo. On one level, ViTo functions as a universal remote control for a home entertainment system. The interface of this device, however, is designed in such a way that it may unobtrusively promote a reduction in the users television viewing while encouraging an increase in the frequency and quantity of non-sedentary activities. The design of ViTo demonstrates how a variety of behavioral science strategies for motivating behavior change can be carefully woven into the operation of a common consumer electronic device. Results of an exploratory evaluation of a single participant using the system in an instrumented home facility are presented.

User-adaptive Reminders for Home-based Medical Tasks - A Case Study

OBJECTIVES We present a prototype adaptive reminder system for home-based medical tasks. The system consists of a mobile device for reminder presentation and ambient sensors to determine opportune moments for reminder delivery. Our objective was to study interaction with the prototype under naturalistic living conditions and gain insight into factors affecting the long-term acceptability of context-sensitive reminder systems for the home setting. METHODS A volunteer participant used the prototype in a residential research facility while adhering to a regimen of simulated medical tasks for ten days. Some reminders were scheduled at fixed times during the day and some were automatically time-shifted based on sensor data. We made a complete video and sensor record of the stay. Finally, the participant commented about his experiences with the system in a debriefing interview. RESULTS Based on this case study, including direct observation of individual alert-action sequences, we make four recommendations for designers of context-sensitive adaptive reminder systems. Captured metrics suggest that adaptive reminders led to faster reaction times and were perceived by the participant as being more useful. CONCLUSIONS The evaluation of context-sensitive systems that overlap into domestic lives is challenging. We believe that the ideal experiment is to deploy such systems in real homes and assess performance longitudinally. This case study in an instrumented live-in facility is a step toward that long-term goal.

Persuasive Cities for Sustainable Wellbeing: Quantified Communities

Can you imagine a city that feels, understands, and cares about your wellbeing? Future cities will reshape human behavior in countless ways. New strategies and models are required for future urban spaces to properly respond to human activity, environmental conditions, and market dynamics. Persuasive urban systems will play an important role in making cities more livable and resource-efficient by addressing current environmental challenges and enabling healthier routines. Persuasive cities research aims at improving wellbeing across societies through applications of socio-psychological theories and their integration with conceptually new urban designs. This research presents an ecosystem of future cities, describes three generic groups of people depending on their susceptibility to persuasive technology, explains the process of defining behavior change, and provides tools for social engineering of persuasive cities. Advancing this research is important as it scaffolds scientific knowledge on how to design persuasive cities and refines guidelines for practical applications in achieving their emergence.

Finding Places: HCI Platform for Public Participation in Refugees’ Accommodation Process

Abstract This paper describes the conception, development and deployment of a novel HCI system for public participation and decision-making. This system was applied for the process of allocating refugee accommodation in the City of Hamburg within the FindingPlaces project (FP) in 2016. The CityScope (CS) – a rapid prototyping platform for urban planning and decision-making – offered a technical solution which was complemented by a workshop process to facilitate effective interaction of multiple participants and stakeholder groups. This paper presents the origins of CS and the evolution of the tangible user interface approach to urban planning and public participation. It further outlines technical features of the system, including custom hardware and software in use, utilization in real-time as well as technical constraints and limitations. Special focus is on the adaptation of the CS technology to the specific demands of Hamburg´s FP project, whose procedures, processes, and results are reflected. The final section analyzes success factors as well as shortcomings of the approach, and indicates further R&D as well as application scenarios for the CS.