Indoor asset tracking is an essential task in many areas of industry such as shipping and warehousing. Widely-used asset tracking technologies typically require supporting infrastructure (signal transponders) to communicate with active tags on the assets. Continuous asset tracking in large indoor spaces like warehouses can be costly, and reliable reference points are needed to calculate asset positions accurately. In this paper, we describe an indoor asset tracking technique for augmented reality (AR) that combines the use of (passive) fiducial markers together with flexible spatial anchors. Our approach, called SABIAT, continuously tracks the approximate location of an asset using spatial anchors and, when needed, the precise location of that asset using fiducial markers. We have applied our SABIAT technique to build a demonstrator system, AR-IPS, to show how assets can be tracked and located inside of a large, multi-level building.

Live coding is an artistic performance practice where computer music and graphics are created, displayed and manipulated in front of a live audience together with projections of the (predominantly text based) computer code. Although the pressures of such performance practices are considerable, until now only familiar programming aids (for example syntax highlighting and textual overlays) have been used to assist live coders. In this paper we integrate an intelligent agent into a live coding system and examine how that agent performed in two contrasting modes of operation-as a recommender, where on request the the agent would generate (but not execute) domain-appropriate code transformations in the performer's text editor, and as a disruptor, where the agent generated and immediately executed changes to the code and the streaming music being performed. A within-subjects study of six live coders suggested that participants of the study preferred the agent's disruptive mode as a mechanism for enhancing the creativity of their live coding performances.

We present details of two imitation-learning, game-playing agents - "SVMBot" and "PETBot" - that feature probabilistic modelling of some low-level combat behaviours. Both bots used a support-vector-machine approach for aiming and a novel, probabilistic model for jumping behaviours. PET-Bot also used a probability-estimation-tree (PET) technique for combat movement. The bots were developed for the FPS game Unreal Tournament 2004 and one of each was submitted to the qualification round (SVMBot) and the final round (PETBot) of the 2009 2K BotPrize competition where they obtained good results. They were then compared with each other as independent variables in a human-computer-interaction (HCI) between-subjects experiment.

Virtual worlds are increasingly being developed to provide a navigable space for museum collections. The Virtual Sydney Rocks (VSR) [3] is one such virtual world that has been constructed as an authentic representation of the area of first European settlement in Australia 230 years ago - from a time just before its settlement until the present day. We constructed two versions of a game for children in order to motivate interaction with, and learning of, the historical content of the VSR. One of these game versions contained a number of fantasy design elements with the idea that their inclusion would motivate children to engage with VSR content in a pleasurable way. A preliminary study with a small number of school-aged children was not able to show that the inclusion of fantasy elements affected either the comprehension of historical facts or the quality of moral judgements made by the children. This study did, however, provide some evidence that interactivity with the relevant parts of the virtual world may have affected the retention of historical facts.

We present the results of two controlled studies of free-improvised ensemble music-making on touch-screens. In our system, updates to an interface of harmonically-selected pitches are broadcast to every touch-screen in response to either a performer pressing a GUI button, or to interventions from an intelligent agent. In our first study, analysis of survey results and performance data indicated significant effects of the button on performer preference, but of the agent on performance length. In the second follow-up study, a mixed-initiative interface, where the presence of the button was interlaced with agent interventions, was developed to leverage both approaches. Comparison of this mixed-initiative interface with the always-on button-plus-agent condition of the first study demonstrated significant preferences for the former. The different approaches were found to shape the creative interactions that take place. Overall, this research offers evidence that an intelligent agent and a networked GUI both improve aspects of improvised ensemble music-making.

We gathered ethnographic evidence from surgeons about the concept of gesture-based control over the display of their patients’ radiographic scan data during surgery. This would give the surgeons direct access to their patients’ scan data without compromising their sterile working field and without needing to rely on other clinicians to interpret display instructions. Our approach involved interviewing surgeons and observing them in the operating theatre. We included evidence from earlier publications in this field and we used a grounded theory approach to analyse our data. Our findings address diversity across the surgical specialties, preoperative versus intraoperative use of the data, preferences for simple natural gestures, the role of another person controlling the display, broad system constraints and the willingness of surgeons to collaborate with their time and effort in this research.

Percussionists are unique among western classical instrumentalists in that their artistic practice is defined by an approach to interaction rather than their instruments. While percussionists are accustomed to exploring non-traditional objects to create music, these objects have yet to encompass touch-screen computing devices to any great extent. The proliferation and popularity of these devices now presents an opportunity to explore their use in combining computer-generated sound together with percussive interaction in a musical ensemble.

Livecoding is an artistic programming practice in which an artist's low-level interaction can be observed with sufficiently high fidelity to allow for transcription and analysis. This paper presents the first reported "coding" of livecoding videos. From an identified corpus of videos available on the web, we coded performances of two different livecoding artists, recording both the (textual) programming edit events and the musical effect of these edits. Our analysis includes a novel, transition-matrix visualisation of the textual and musical dimensions of this data to create a "performer fingerprint". We show how detailed transcriptions of livecoding videos can be made which, we hope, will provide a foundation for further research into describing and understanding livecoding.

Network connectivity offers the potential for a group of musicians to play together over the network. This paper describes a trans-Atlantic networked musical livecoding performance between Andrew Sorensen in Germany (at the Schloss Daghstuhl conference on Collaboration and Learning through Live Coding) and Ben Swift in San Jose (at YL/HCC) in September 2013. In this paper we describe the infrastructure developed to enable this performance.

This paper proposes that online HCI studies (such as web-surveys and remotely monitored usability tests) can benefit from statistical data analysis using modern statistical learning methods such as classification and regression trees (CARTs). Applying CARTs to the often large amount of data yielded by online studies can easily provide clarity concerning the most important effects underlying experimental data in situations where myriad possible factors are under consideration. The feedback provided by such an analysis can also provide valuable reflection on the experimental methodology. We discuss these matters with reference to a study of 1300 participants in a structured experiment concerned with head-interaction techniques for first-person-shooter games.

A pilot case-study of the ICT systems of two self-managed Aboriginal councils in the Australian state of New South Wales has been undertaken in order to assess the nature and potential of software interventions. Our study indicates that the development of task-driven software interfaces could significantly support the processes and activities of Aboriginal council management and could contribute to alleviating the stress associated with current systems. Our vision is to develop these interfaces together with networking support for peer-to-peer collaboration between councils, compliance agencies and trusted advisers. The workflows themselves would be built and refined in a collaborative fashion between users together with some automated support.

With the increasing use of commodity RGB-D cameras for computer vision, robotics, mixed and augmented reality and other areas, it is of significant practical interest to calibrate the relative pose between a depth (D) camera and an RGB camera in these types of setups. In this paper, we propose a new single-shot, correspondence-free method to extrinsically calibrate a generically configured RGB-D camera rig. We formulate the extrinsic calibration problem as one of geometric 2D-3D registration which exploits scene constraints to achieve single-shot extrinsic calibration. Our method first reconstructs sparse point clouds from a single-view 2D image. These sparse point clouds are then registered with dense point clouds from the depth camera. Finally, we directly optimize the warping quality by evaluating scene constraints in 3D point clouds. Our single-shot extrinsic calibration method does not require correspondences across multiple color images or across different modalities and it is more flexible than existing methods. The scene constraints can be very simple and we demonstrate that a scene containing three sheets of paper is sufficient to obtain reliable calibration and with a lower geometric error than existing methods.

Increasingly, the sophistication of modern computer-gaming systems is becoming comparable to that of immersive, virtual reality (VR) environments, and the popular VR research topic of “presence” is now being explored in the context of computer games. The explosion of popularity of networked gameplay and the movement of computing infrastructure on to the Internet and the cloud mean that technical anomalies such as network latency, dropouts, and so on, may increasingly disrupt players' experience of presence. In this article, a study of these “Breaks in Presence” (BIPs), which examines a networked, first-person-shooter game in an immersive virtual environment, is presented. Our study investigates how participants react to BIPs in terms of their impact on participants' levels of presence and in terms of the time needed for participants to recover from BIPs. Four distinct BIP types, which were selected because of their practical significance and because of their relevance to an established model for presence, were tested. The effects of two contrasting game modes (a low-involvement “navigation game” and a high-involvement “combat game”) on the perceptions of these BIPs are analyzed. As part of our experimental procedure a new video-cued-recall slider technique is introduced. Our study shows that participants experience different levels of impact and recovery from BIPs and that the perceptions of impact of BIPs depend on the overall sense of presence as well as being task dependent. The article shows that recovery time seems to be a well-defined concept and that an overall measure of recovery time exhibits believable correlations with overall presence, with the overall number of BIPs (including “spontaneous” BIPs) and with user characteristics. The article also shows that the slider data for recovery time from BIPs provide evidence for a smooth variation of presence during an immersive experience. It is found that perceptions of impact and recovery time behave differently and that, intriguingly, recovery time appears to be much more independent of game mode than impact is. Evidence is found of strong carry-over effects in participants' recollections of the impact of BIPs from one game experience to the next is found. Results from our slider technique appear to show general agreement with results from a postexperiment questionnaire, and our study motivates the usefulness of our slider technique for future experiments.

The act of computer programming is generally considered to be temporally removed from a computer program's execution. In this paper we discuss the idea of programming as an activity that takes place within the temporal bounds of a real-time computational process and its interactions with the physical world. We ground these ideas within the con- text of livecoding -- a live audiovisual performance practice. We then describe how the development of the programming environment "Impromptu" has addressed our ideas of programming with time and the notion of the programmer as an agent in a cyber-physical system.

A previous paper [Schou and Gardner 2007] has described a project to port a games engine into a two-walled Immersive Projection Theatre (IPT) and to interact with that environment using the Nintendo "Wii" Remote[Nintendo 2008]. In the present work, we update this project to describe how Wii controllers have now been demonstrated to work with a custom-built, multiple "Sensor Bar" array to achieve a greater coverage of the IPT.