Gait parameters have been established as a health biomarker for physical and cognitive health for older adults. Extracting these parameters however requires specialist equipment such as on-body sensors or video-based systems. Identifying low-cost techniques to capture gait parameters can open the opportunity for in-home monitoring of gait related biomarkers. In this study, we demonstrate that gait can be analysed in in-door at-home settings using only the sound of footsteps. To establish a comparative baseline, we use inertial measurement units (IMUs) and video footages as reference systems alongside our proposed acoustics-based approach. Gait parameters, specifically cadence, step time, and stride time, were extracted from audio, video, and IMU data streams recorded from 10 community-dwelling older adults. Bland Altman Analysis was performed to assess the agreement between the parameter values from the three different systems. We found that the gait parameters derived from our acoustics-only system exhibit relative standard errors of 0.71% and 0.58% against IMU and video-based systems, respectively.

Location-aware mobile guides are a popular technology for enhancing the experience of heritage walks in historical outdoor sites. Smartphones, as typical mediums for such systems, have been criticised for limiting users’ opportunities for embodied engagement with the environment. In this work, we investigate how display technologies beyond the traditional personal mobile screen can facilitate embodied experiences during outdoor heritage walks. To do this, we revisit the use of portable projected displays as a medium that allows us to explore the effects of overt and blended displays in this context. We conducted a study with 42 participants on an outdoor heritage walk, using two display modalities: smartphone and projected display. We discovered that besides the display modality, users’ attitude toward technology, their embodied relationship with the device, and incorporation of spatial aspects in interaction play a key role in generating engagement and shaping the experience of heritage walks.

Performers acutely need but lack tools to remotely rehearse and create live theatre, particularly due to global restrictions on social interactions during the Covid-19 pandemic. No studies, however, have heretofore examined how remote video-collaboration affects performance. This paper presents the findings of a field study with 16 domain experts over six weeks investigating how tele-immersion affects the rehearsal and performance of improvisational theatre. To conduct the study, an original media server was developed for co-locating remote performers into shared virtual 3D environments which were accessed through popular video conferencing software. The results of this qualitative study indicate that tele-immersive environments uniquely provide performers with a strong sense of co- presence, feelings of physical connection, and an increased ability to enter the social-flow states required for improvisational theatre. Based on our observations, we put forward design recommendations for video collaboration tools tailored to the unique demands of live performance.

Typical approaches in detecting social interactions consider the use of co-location as a proxy for real-world interactions. Such approaches can under-perform in challenging situations where multiple social interactions can occur in close proximity to each other. In this paper, we present a novel approach to detect co-located social interactions using smartphones. Next2Me relies on the use of WiFi signals and audio signals to accurately distinguish social groups interacting within a few meters from each other. Through a range of real-world experiments, we demonstrate a technique that utilises WiFi fingerprinting, along with sound fingerprinting to identify social groups. Experimental results show that Next2Me can achieve a precision of 88% within noisy environments, including smartphones that are placed in users' pockets, whilst maintaining a very low energy footprint (<3% of battery capacity per day).

In many work environments, serendipitous interactions between members of different groups may lead to enhanced productivity, collaboration and knowledge dissemination. Two factors that may have an influence on such interactions are cultural differences between individuals in highly multicultural workplaces, and the layout and physical spaces of the workplace itself. In this work, we investigate how these two factors may facilitate or hinder inter-group interactions in the workplace. We analyze traces collected using wearable electronic badges to capture face-to-face interactions and mobility patterns of employees in a research laboratory in the UK. We observe that those who interact with people of different roles tend to come from collectivist cultures that value relationships and where people tend to be comfortable with social hierarchies, and that some locations in particular are more likely to host serendipitous interactions, knowledge that could be used by organizations to enhance communication and productivity.

The layouts of the buildings we live in shape our everyday lives. In office environments, building spaces affect employees' communication, which is crucial for productivity and innovation. However, accurate measurement of how spatial layouts affect interactions is a major challenge and traditional techniques may not give an objective view.

Studies of automotive traffic have shown that on average 30% of traffic in congested urban areas is due to cruising drivers looking for parking. While we have witnessed a push towards sensing technologies to monitor real-time parking availability, instrumenting on-street parking throughout a city is a considerable investment. In this paper, we present ParkSense, a smartphone based sensing system that detects if a driver has vacated a parking spot. ParkSense leverages the ubiquitous Wi-Fi beacons in urban areas for sensing unparking events. It utilizes a robust Wi-Fi signature matching approach to detect driver's return to the parked vehicle. Moreover, it uses a novel approach based on the rate of change of Wi-Fi beacons to sense if the user has started driving. We show that the rate of change of the observed beacons is highly correlated with actual user speed and is a good indicator of whether a user is in a vehicle. Through empirical evaluation, we demonstrate that our approach has a significantly smaller energy footprint than traditional location sensors like GPS and Wi-Fi based positioning while still maintaining sufficient accuracy.

Mobile phones play a pivotal role in supporting ubiquitous and unobtrusive sensing of human activities. However, maintaining a highly accurate record of a user's behavior throughout the day imposes significant energy demands on the phone's battery. In this paper, we present the design, implementation, and evaluation of METIS: an adaptive mobile sensing platform that efficiently supports social sensing applications. The platform implements a novel sensor task distribution scheme that dynamically decides whether to perform sensing on the phone or in the infrastructure, considering the energy consumption, accuracy, and mobility patterns of the user. By comparing the sensing distribution scheme with sensing performed solely on the phone or exclusively on the fixed remote sensors, we show, through benchmarks using real traces, that the opportunistic sensing distribution achieves over 60% and 40% energy savings, respectively. This is confirmed through a real world deployment in an office environment for over a month: we developed a social application over our frameworks, that is able to infer the collaborations and meetings of the users. In this setting the system preserves over 35% more battery life over pure phone sensing.

In this paper we reflect on our long-term experiences of developing, deploying and supporting an experimental digital signage system. Existing public display systems almost always feature a single point of control that is responsible for scheduling content for presentation on the network and provide sophisticated mechanisms for controlling play-out timing and relative ordering. Our experiences suggest that such complex feature-sets are unnecessary in many cases and may be counter productive in signage systems. We describe an alternative, simpler paradigm for encouraging widespread use of signage systems based on shared 'content channels' between content providers and display owners. Our system has been in continuous use for approximately 3 years. We reflect and draw lessons from how our user community has adopted and used the resulting public display network. We believe that these reflections will be of benefit to future developers of ubiquitous display networks.

An increasing number of sensor networks have been deployed to monitor a variety of conditions and situations. At the same time, more and more applications are starting to rely on the data from sensor networks to provide users with (near) real-time information and conditions. This increasing demand of users for accurate information about natural and surrounding phoenomena is creating a business case for application providers.

The NEMO project is exploring the use of mobile sensor nodes toaugment physical work artefacts in order to ensure compliance with health and safety regulations. In this paper we present our experiences of designing and deploying the NEMO Hand Arm Vibration (HAV) monitoring system. Long term exposure to hand arm vibration can lead to serious health conditions and the NEMO HAV monitoring system offers an integrated architecture for capturing HAV exposure data in the field, providing feedback about exposure levels both in the field and as input to a back-end database. Our design allows health and safety regulations specified at the enterprise level to be embedded within the wireless sensor nodes allowing them to operate without any infrastructural support. The system has been the subject of a two week field trial that took place with the collaboration of a British construction and maintenance company. During the field trial, the NEMO HAV system was deployed to a roa dmaintenance patching gang and data were collected on HAV exposure caused by hydraulic drills. The paper reports on the results of the field trial and the lessons learned through the real deployment of the system.

In this paper, we describe our experiences of developing and evaluating GUIDE, an intelligent electronic tourist guide. The GUIDE system has been built to overcome many of the limitations of the traditional information and navigation tools available to city visitors. For example, group-based tours are inherently inflexible with fixed starting times and fixed durations and (like most guidebooks) are constrained by the need to satisfy the interests of the majority rather than the specific interests of individuals. Following a period of requirements capture, involving experts in the field of tourism, we developed and installed a system for use by visitors to Lancaster. The system combines mobile computing technologies with a wireless infrastructure to present city visitors with information tailored to both their personal and environmental contexts. In this paper we present an evaluation of GUIDE, focusing on the quality of the visitor's experience when using the system.