tocauthor: Hammerla_N* : Human-Computer Interaction Bibliography Search

Expressy: Using a Wrist-worn Inertial Measurement Unit to Add Expressiveness to Touch-based Interactions Touch Interaction / Wilkinson, Gerard / Kharrufa, Ahmed / Hook, Jonathan / Pursglove, Bradley / Wood, Gavin / Haeuser, Hendrik / Hammerla, Nils Y. / Hodges, Steve / Olivier, Patrick Proceedings of the ACM CHI'16 Conference on Human Factors in Computing Systems 2016-05-07 v.1 p.2832-2844

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Summary: Expressiveness, which we define as the extent to which rich and complex intent can be conveyed through action, is a vital aspect of many human interactions. For instance, paint on canvas is said to be an expressive medium, because it affords the artist the ability to convey multifaceted emotional intent through intricate manipulations of a brush. To date, touch devices have failed to offer users a level of expressiveness in their interactions that rivals that experienced by the painter and those completing other skilled physical tasks. We investigate how data about hand movement -- provided by a motion sensor, similar to those found in many smart watches or fitness trackers -- can be used to expand the expressiveness of touch interactions. We begin by introducing a conceptual model that formalizes a design space of possible expressive touch interactions. We then describe and evaluate Expressy, an approach that uses a wrist-worn inertial measurement unit to detect and classify qualities of touch interaction that extend beyond those offered by today's typical sensing hardware. We conclude by describing a number of sample applications, which demonstrate the enhanced, expressive interaction capabilities made possible by Expressy.

Video Showcase: Using Expressy to Showcase Expressiveness in Touch-based Interactions Video Showcase Presentations / Wilkinson, Gerard / Green, David Philip / Wood, Gavin / Kharrufa, Ahmed / Hook, Jonathan / Pursglove, Bradley / Haeuser, Hendrik / Hammerla, Nils Y. / Hodges, Steve / Olivier, Patrick Extended Abstracts of the ACM CHI'16 Conference on Human Factors in Computing Systems 2016-05-07 v.2 p.11

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Summary: We present a video demonstration of how information about hand movements, generated from a wrist-worn IMU (inertial measurement unit), can be used to provide expressiveness to touch-based interactions. The IMU identifies features that were not previously accessible, such as instantaneous force, wrist roll and pitch. We demonstrate a range of applications that have been extended using Expressy, a system we describe in more detail in the full paper [1]. Tap force allows users to express their intent behind an interaction before touch. Wrist roll and pitch enriches the touch during the interaction. Flick force and wrist roll allows users to follow-up their touch interaction.

Interactivity: Using Expressy to Demonstrate Expressiveness in Touch-based Interactions Interactivity Demos / Wilkinson, Gerard / Wood, Gavin / Hook, Jonathan / Nappey, Tom / Kharrufa, Ahmed / Pursglove, Bradley / Haeuser, Hendrik / Hammerla, Nils Y. / Hodges, Steve / Olivier, Patrick Extended Abstracts of the ACM CHI'16 Conference on Human Factors in Computing Systems 2016-05-07 v.2 p.3800-3803

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Summary: We present an interactivity demonstration of Expressy. A system that augments existing touchscreen devices with a variety of continuous expressive interaction capabilities, using movement data from a wrist-worn IMU. Our demonstration comprises a set of applications that show how the expressive touch interaction capabilities, offered by Expressy, can enable intuitive and meaningful interactions, in contexts including productivity, entertainment and lifestyle apps. This demo submission accompanies a full paper, describing a conceptual model of expressive touch interaction and the implementation and evaluation of Expressy.

Diri -- the actuated helium balloon: a study of autonomous behaviour in interfaces Interacting with animals and flying robots / Nowacka, Diana / Hammerla, Nils Y. / Elsden, Chris / Plötz, Thomas / Kirk, David Proceedings of the 2015 International Conference on Ubiquitous Computing 2015-09-07 p.349-360

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Summary: Research on actuated interfaces has shown that people respond in certain socialized ways to interfaces that exhibit autonomous behaviours. We wished to explore the elements of design that drive people to regard an autonomous, interactive system as a social agent. To explore perceptions of autonomous behaviour in interfaces we created Diri -- an autonomous helium balloon, used to document activity in spaces. We implemented two different technological sophistications of Diri, to compare the outcomes of our design decisions. We present our design process, technical details and evaluation workshops, concluding with implications for designing for autonomous behaviour in interfaces.

Let's (not) stick together: pairwise similarity biases cross-validation in activity recognition Sensing and recognition / Hammerla, Nils Y. / Plötz, Thomas Proceedings of the 2015 International Conference on Ubiquitous Computing 2015-09-07 p.1041-1051

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Summary: The ability to generalise towards either new users or unforeseen behaviours is a key requirement for activity recognition systems in ubiquitous computing. Differences in recognition performance for the two application cases can be significant, and user-dependent performance is typically assumed to be an upper bound on performance. We demonstrate that this assumption does not hold for the widely used cross-validation evaluation scheme that is typically employed both during system bootstrapping and for reporting results. We describe how the characteristics of segmented time-series data render random cross-validation a poor fit, as adjacent segments are not statistically independent. We develop an alternative approach -- meta-segmented cross validation -- that explicitly circumvents this issue and evaluate it on two data-sets. Results indicate a significant drop in performance across a variety of feature extraction and classification methods if this bias is removed, and that prolonged, repetitive activities are particularly affected.

CueS: cueing for upper limb rehabilitation in stroke Ageing, health and wellbeing / Holden, Amey / McNaney, Róisín / Balaam, Madeline / Thompson, Robin / Hammerla, Nils / Ploetz, Thomas / Jackson, Dan / Price, Christopher / Brkic, Lianne / Olivier, Patrick Proceedings of the 2015 British Human Computer Interaction Conference 2015-07-13 p.18-25

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Summary: Upper limb weakness is one of the most distressing, long-term consequences of stroke and can be difficult to rehabilitate due to an overreliance on the opposing limb in everyday life. Previous studies have shown potential for cueing to improve upper limb rehabilitation, although these have been conducted in clinical settings. In this paper we describe CueS, a wrist worn cueing device which prompts the wearer to move their upper limb more frequently in their day to day lives. We conducted two, week-long 'in the wild' deployments of CueS with seven participants to obtain reflections and experiences around using the device. All participants reported increased general activity levels from wearing CueS and objective data showed increased levels of activity following cue provision. We reflect upon the potential of wearable cueing devices for upper limb rehabilitation after stroke.

ClimbAX: skill assessment for climbing enthusiasts Sport and fitness / Ladha, Cassim / Hammerla, Nils Y. / Olivier, Patrick / Plötz, Thomas Proceedings of the 2013 International Joint Conference on Pervasive and Ubiquitous Computing 2013-09-08 v.1 p.235-244

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Summary: In recent years the sport of climbing has seen consistent increase in popularity. Climbing requires a complex skill set for successful and safe exercising. While elite climbers receive intensive expert coaching to refine this skill set, this progression approach is not viable for the amateur population. We have developed ClimbAX -- a climbing performance analysis system that aims for replicating expert assessments and thus represents a first step towards an automatic coaching system for climbing enthusiasts. Through an accelerometer based wearable sensing platform, climber's movements are captured. An automatic analysis procedure detects climbing sessions and moves, which form the basis for subsequent performance assessment. The assessment parameters are derived from sports science literature and include: power, control, stability, speed. ClimbAX was evaluated in a large case study with 53 climbers under competition settings. We report a strong correlation between predicted scores and official competition results, which demonstrate the effectiveness of our automatic skill assessment system.

Dog's life: wearable activity recognition for dogs Domestic computing / Ladha, Cassim / Hammerla, Nils / Hughes, Emma / Olivier, Patrick / Ploetz, Thomas Proceedings of the 2013 International Joint Conference on Pervasive and Ubiquitous Computing 2013-09-08 v.1 p.415-418

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Summary: Health and well-being of dogs, either domesticated pets or service animals, are major concerns that are taken seriously for ethical, emotional, and financial reasons. Welfare assessments in dogs rely on objective observations of both frequency and variability of individual behaviour traits, which is often difficult to obtain in a dog's everyday life. In this paper we have identified a set of activities, which are linked to behaviour traits that are relevant for a dog's wellbeing. We developed a collar-worn accelerometry platform that records dog behaviours in naturalistic environments. A statistical classification framework is used for recognising dog activities. In an experimental evaluation we analysed the naturalistic behaviour of 18 dogs and were able to recognise a total of 17 different activities with approximately 70% classification accuracy. The presented system is the first of its kind that allows for robust and detailed analysis of dog activities in naturalistic environments.

Automatic correction of annotation boundaries in activity datasets by class separation maximization Workshop: international workshop on human activity sensing corpus and its application (HASCA2013) / Kirkham, Reuben / Khan, Aftab / Bhattacharya, Sourav / Hammerla, Nils / Mellor, Sebastian / Roggen, Daniel / Ploetz, Thomas Adjunct Proceedings of the 2013 International Joint Conference on Pervasive and Ubiquitous Computing 2013-09-08 v.2 p.673-678

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Summary: t is challenging to precisely identify the boundary of activities in order to annotate the activity datasets required to train activity recognition systems. This is the case for experts, as well as non-experts who may be recruited for crowd-sourcing paradigms to reduce the annotation effort or speed up the process by distributing the task over multiple annotators. We present a method to automatically adjust annotation boundaries, presuming a correct annotation label, but imprecise boundaries, otherwise known as "label jitter". The approach maximizes the Fukunaga Class-Separability, applied to time series. Evaluations on a standard benchmark dataset showed statistically significant improvements from the initial jittery annotations.

On preserving statistical characteristics of accelerometry data using their empirical cumulative distribution Context and awareness / Hammerla, Nils Y. / Kirkham, Reuben / Andras, Peter / Ploetz, Thomas Proceedings of the 2013 International Symposium on Wearable Computers 2013-09-08 p.65-68

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Summary: The majority of activity recognition systems in wearable computing rely on a set of statistical measures, such as means and moments, extracted from short frames of continuous sensor measurements to perform recognition. These features implicitly quantify the distribution of data observed in each frame. However, feature selection remains challenging and labour intensive, rendering a more generic method to quantify distributions in accelerometer data much desired. In this paper we present the ECDF representation, a novel approach to preserve characteristics of arbitrary distributions for feature extraction, which is particularly suitable for embedded applications. In extensive experiments on six publicly available datasets we demonstrate that it outperforms common approaches to feature extraction across a wide variety of tasks.

Touchbugs: actuated tangibles on multi-touch tables Papers: tables and floors / Nowacka, Diana / Ladha, Karim / Hammerla, Nils Y. / Jackson, Daniel / Ladha, Cassim / Rukzio, Enrico / Olivier, Patrick Proceedings of ACM CHI 2013 Conference on Human Factors in Computing Systems 2013-04-27 v.1 p.759-762

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Summary: We present a novel approach to graspable interfaces using Touchbugs, actuated physical objects for interacting with interactive surface computing applications. Touchbugs are active tangibles that are able to move across surfaces by employing vibrating motors and can communicate with camera based multi-touch surfaces using infrared LEDs. Touchbug's embedded inertial sensors and computational capabilities open a new interaction space by providing autonomous capabilities for tangibles that allow goal directed behavior.

Automatic assessment of problem behavior in individuals with developmental disabilities Pediatric informatics / Plötz, Thomas / Hammerla, Nils Y. / Rozga, Agata / Reavis, Andrea / Call, Nathan / Abowd, Gregory D. Proceedings of the 2012 International Conference on Ubiquitous Computing 2012-09-05 p.391-400

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Summary: Severe behavior problems of children with developmental disabilities often require intervention by specialists. These specialists rely on direct observation of the behavior, usually in a controlled clinical environment. In this paper, we present a technique for using on-body accelerometers to assist in automated classification of problem behavior during such direct observation. Using simulated data of episodes of severe behavior acted out by trained specialists, we demonstrate how machine learning techniques can be used to segment relevant behavioral episodes from a continuous sensor stream and to classify them into distinct categories of severe behavior (aggression, disruption, and self-injury). We further validate our approach by demonstrating it produces no false positives when applied to a publicly accessible dataset of activities of daily living. Finally, we show promising classification results when our sensing and analysis system is applied to data from a real assessment session conducted with a child exhibiting problem behaviors.

Cueing for drooling in Parkinson's disease Health 3: online communities & social interaction / McNaney, Roisin / Lindsay, Stephen / Ladha, Karim / Ladha, Cassim / Schofield, Guy / Ploetz, Thomas / Hammerla, Nils / Jackson, Daniel / Walker, Richard / Miller, Nick / Olivier, Patrick Proceedings of ACM CHI 2011 Conference on Human Factors in Computing Systems 2011-05-07 v.1 p.619-622

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Summary: We present the development of a socially acceptable cueing device for drooling in Parkinson's disease (PD). Sialorrhea, or drooling, is a significant problem associated with PD and has a strong negative emotional impact on those who experience it. Previous studies have shown the potential for managing drooling by using a cueing device. However, the devices used in these studies were deemed unacceptable by their users due to factors such as hearing impairment and social embarrassment. We conducted exploratory scoping work and high fidelity iterative prototyping with people with PD to get their input on the design of a cueing aid and this has given us an insight into challenges that confront users with PD and limit device usability and acceptability. The key finding from working with people with PD was the need for the device to be socially acceptable.