LightSense: enabling spatially aware handheld interaction devices

devices. The outside-in approach tracks the light source and streams the data to the phone over Bluetooth. a) A wall-mounted map with embedded light sensors provides hotspot tracking. b) A table-top setup tracks the phone with a camera through a diffused glass surface. c) The spatially aware device augments a physical map with a detailed interactive road map of the area of interest. The vision of spatially aware handheld interaction devices has been hard to realize. The difficulties in solving the general tracking problem for small devices have been addressed by several research groups and examples of issues are performance, hardware availability and platform independency. We present Light-Sense, an approach that employs commercially available components to achieve robust tracking of cell phone LEDs, without any modifications to the device. Cell phones can thus be promoted to interaction and display devices in ubiquitous installations of systems such as the ones we present here. This could enable a new generation of spatially aware handheld interaction devices that would unobtrusively empower and assist us in our everyday tasks. CR Categories: H.5.1 [Multimedia Information Systems]: Artificial, augmented, and virtual realities; H.5.2. [User Interfaces]: Graphical user interfaces, Input devices and strategies; I.3.6 [Methodology and Techniques]: Interaction techniques

Designable Visual Markers for Mobile Human-Computer Interaction

Visual markers are graphic symbols designed to be easily recognised by machines. They are traditionally used to track goods, but there is increasing interest in their application to mobile human-computer interaction (HCI). By scanning a visual marker through a camera phone, users can retrieve localised information and access mobile services. In particular the dissertation examines the application of visual markers to physical tagging: practices of association of digital information with physical items. One missed opportunity in current visual marker systems is that the markers themselves cannot be visually designed; they are not expressive to humans, and thus fail to convey information before being scanned. To address this limitation, this dissertation introduces the idea of designable markers, visual markers that are both machine-readable and visually communicative to humans, and presents an investigation of the ways in which they can support mobile human-computer interaction. The application of designable visual markers to the creation of mobile interfaces is explored through a variety of methods: through formal usability experiments, through the creation and analysis of example designs, as well as through the qualitative analysis of two field trials. All three approaches were enabled by the engineering and development of d-touch, an actual recognition system that supports designable visual markers and by its integration in a variety of applications and experimental probes. D-touch is based on image topology, and its markers are defined in terms of constraints on the nesting of dark and light regions. The constraints imposed by d-touch are flexible enough to allow novice users to create markers which are visually expressive and at the same time machine readable. A user study demonstrates how such system enables people to design their own functional visual markers, determining their aesthetic qualities and what they visually communicate to others. A desktop application to support users in the creation of valid markers, the d-touch analyser, is presented and its usefulness is demonstrated through the same study. A formal usability experiment comparing five variations of marker-based interfaces on keypad and touch-screen phones shows that all of them allow users to reliably select targets within, on average, less than 4 seconds. Participants of the experiment reported a strong preference for interfaces that involve only marker scanning, compared to those that require a combination of marker scanning and key-presses or touch selections. Example designs of mobile interface generated by the author as well as others are presented to expose how the d-touch recognition system can be integrated in mobile applications. The examples illustrate a variety of ways in which markers can be used to augment printed materials such as cards, books and product packages, adding to them interactive capabilities. The examples show also different approaches to marker design, ranging from simple and recognisable iconic design, to symbols that integrate cues about the interactive functionality, to making them invisible by hiding them in existing graphics. Finally, the dissertation reports and analyses two field trials conducted to study what practices of physical tagging can emerge from, and be supported by, the use of markers. The trials were centred around the use of uWiki, a functional prototype based on d-touch, that allows users to associate digital content to markers printed on physical tags that can be affixed to objects or buildings. Observations show that a variety of practices emerge around the use of this technology, indicating that they provide a rich medium that has potential to attract the interest of real users. Though the results of this work are preliminary, they serve to demonstrate the range of potential for the future of such systems

CIRCADIAN COMPUTING: SENSING AND STABILIZING BIOLOGICAL RHYTHMS

This dissertation lays the groundwork for Circadian Computing with a novel and broad vision of technologies that support and adapt to our innate biological rhythms. Similar to most terrestrial organisms, human physiology and behavior are shaped by a 24-hour periodicity known as circadian rhythm. Indeed, almost every neurobehavioral process including our sleep, metabolism, cognitive performance, and mood reflects circadian rhythms. These rhythms ensure synchronization across different processes and as such, are crucial for our health and well-being. Persistent circadian disruption increases risk for cancer, obesity, and cardiovascular diseases. It has been associated with occupational accidents and serious loss of productivity in the workplace as well. Recent findings have also started identifying links between circadian disruption and mental illnesses including bipolar disorder and schizophrenia. However, in our modern world, circadian disruption is becoming increasingly widespread. The invention of artificial light fundamentally changed our ancestral sleep and wakeup patterns. Since then, we have gradually moved towards a 24-hour society. The recent development in entertainment and communication technologies has also resulted in an “always-on” ethos. The resulting trend is worrisome. Sleep pathologies are reaching an epidemic level with 70\% of the population suffering from significant circadian disruptions. As a result, recently there has been an increased focus on monitoring and identifying disruptions in circadian rhythms. However, these methods and findings are often limited to controlled lab environments. As a result, they are not adequate for granular monitoring of circadian disruptions in the wild over a longitudinal period of time. As such, there is a need for novel pervasive technologies for tracking, monitoring, and modeling circadian disruptions and its impact in the real world. There is also an opportunity for developing intervention tools for maintaining circadian stability. This dissertation is a leading step towards the broad vision of circadian-aware technologies for sensing, adapting to, and stabilizing our innate biological rhythms. In my PhD work, I have shown the feasibility of bringing a circadian-aware perspective across different application domains. Specifically, I have developed and evaluated methods for unobtrusively assessing circadian disruptions. I have also showed that behavioral and contextual data can be used for modeling and predicting alertness — a circadian process integral to our cognitive performance. I have also developed, deployed, and evaluated a data driven tool focusing on identifying circadian anomalies in patients with bipolar disorder. With this groundwork in place, I believe that there is an exciting opportunity lying ahead for Circadian Computing. In particular, circadian-aware technologies can potentially reshape a number of application domains including education and learning, optimized scheduling, mental health care, and chronotherapy. I hope this dissertation motivates a circadian perspective in future technology development and contributes to the shared effort of improving our productivity, health, and well-being