Immersive telepresence, when a user views the video stream of a 360° camera in a remote environment using a Head Mounted Display (HMD), has great potential to improve the sense of being in a remote environment. In most cases of immersive robotic telepresence, the camera is mounted on a mobile robot which increases the portion of the environment that the remote user can explore. However, robot motions can induce unpleasant symptoms associated with Virtual Reality (VR) sickness, degrading the overall user experience. Previous research has shown that unwinding the rotations of the robot, that is, decoupling the rotations that the camera undergoes due to robot motions from what is seen by the user, can increase user comfort and reduce VR sickness. However, that work considered a virtual environment and a simulated robot. In this work, to test whether the same hypotheses hold when the video stream from a real camera is used, we carried out a user study ($n=36$) in which the unwinding rotations method was compared against coupled rotations in a task completed through a panoramic camera mounted on a robotic arm. Furthermore, within an inspection task which involved translations and rotations in three dimensions, we tested whether unwinding the robot rotations impacted the performance of users. The results show that the users found the unwinding rotations method to be more comfortable and preferable, and that a reduced level of VR sickness can be achieved without a significant impact on task performance.

According to previous research, humans are generally poor at adapting to earth-discrepant gravity, especially in Virtual Reality (VR), which cannot simulate the effects of gravity on the physical body. Most of the previous VR research on gravity adaptation has used perceptual or interception tasks, although adaptation to these tasks seems to be especially challenging compared to tasks with a more pronounced motor component. This article describes the results of two between-subjects studies ( n = 60 and n = 42) that investigated adaptation to increased gravity simulated by an interactive VR experience. The experimental procedure was identical in both studies: In the adaptation phase, one group was trained to throw a ball at a target using Valve Index motion controllers in gravity that was simulated at five times of earth’s gravity (hypergravity group), whereas another group threw at a longer-distance target under normal gravity (normal gravity group) so both groups had to exert the same amount of force when throwing (approximated manually in Study 1 and mathematically in Study 2). Then, in the measurement phase, both groups repeatedly threw a virtual ball at targets in normal gravity. In this phase, the trajectory of the ball was hidden at the moment of release so that the participants had to rely on their internal model of gravity to hit the targets rather than on visual feedback. Target distances were placed within the same range for both groups in the measurement phase. According to our preregistered hypotheses, we predicted that the hypergravity group would display worse overall throwing accuracy and would specifically overshoot the target more often than the normal gravity group. Our experimental data supported both hypotheses in both studies. The findings indicate that training an interactive task in higher simulated gravity led participants in both studies to update their internal gravity models, and therefore, some adaptation to higher gravity did indeed occur. However, our exploratory analysis also indicates that the participants in the hypergravity group began to gradually regain their throwing accuracy throughout the course of the measurement phase.

In this paper, we show that Virtual Reality (VR) sickness is associated with a reduction in attention, which was detected with the P3b Event-Related Potential (ERP) component from electroencephalography (EEG) measurements collected in a dual-task paradigm. We hypothesized that sickness symptoms such as nausea, eyestrain, and fatigue would reduce the users' capacity to pay attention to tasks completed in a virtual environment, and that this reduction in attention would be dynamically reflected in a decrease of the P3b amplitude while VR sickness was experienced. In a user study, participants were taken on a tour through a museum in VR along paths with varying amounts of rotation, shown previously to cause different levels of VR sickness. While paying attention to the virtual museum (the primary task), participants were asked to silently count tones of a different frequency (the secondary task). Control measurements for comparison against the VR sickness conditions were taken when the users were not wearing the Head-Mounted Display (HMD) and while they were immersed in VR but not moving through the environment. This exploratory study shows, across multiple analyses, that the effect mean amplitude of the P3b collected during the task is associated with both sickness severity measured after the task with a questionnaire (SSQ) and with the number of counting errors on the secondary task. Thus, VR sickness may impair attention and task performance, and these changes in attention can be tracked with ERP measures as they happen, without asking participants to assess their sickness symptoms in the moment.

We propose unwinding the rotations experienced by the user of an immersive telepresence robot to improve comfort and reduce VR sickness of the user. By immersive telepresence we refer to a situation where a 360° camera on top of a mobile robot is streaming video and audio into a head-mounted display worn by a remote user possibly far away. Thus, it enables the user to be present at the robot's location, look around by turning the head and communicate with people near the robot. By unwinding the rotations of the camera frame, the user's viewpoint is not changed when the robot rotates. The user can change her viewpoint only by physically rotating in her local setting; as visual rotation without the corresponding vestibular stimulation is a major source of VR sickness, physical rotation by the user is expected to reduce VR sickness. We implemented unwinding the rotations for a simulated robot traversing a virtual environment and ran a user study (N=34) comparing unwinding rotations to user's viewpoint turning when the robot turns. Our results show that the users found unwound rotations more preferable and comfortable and that it reduced their level of VR sickness. We also present further results about the users' path integration capabilities, viewing directions, and subjective observations of the robot's speed and distances to simulated people and objects.

This paper considers the problem of enabling the user to modify the path of a telepresence robot. The robot is capable of autonomously navigating to a goal predefined by the user, but the user might still want to modify the path, for example, to go further away from other people, or to go closer to landmarks she wants to see on the way. We propose Human-Influenced Dynamic Window Approach (HI-DWA), a shared control method aimed for telepresence robots based on Dynamic Window Approach (DWA) that allows the user to influence the control input given to the robot. To verify the proposed method, we performed a user study (N=32) in Virtual Reality (VR) to compare HI-DWA with switching between autonomous navigation and manual control for controlling a simulated telepresence robot moving in a virtual environment. Results showed that users reached their goal faster using HI-DWA controller and found it easier to use. Preference between the two methods was split equally. Qualitative analysis revealed that a major reason for the participants that preferred switching between two modes was the feeling of control. We also analyzed the effect of different input methods, joystick and gesture, on the preference and perceived workload.

In this paper, we present an implementation of a leaning-based control of a differential drive telepresence robot and a user study in simulation, with the goal of bringing the same functionality to a real telepresence robot. The participants used a balance board to control the robot and viewed the virtual environment through a head-mounted display. The main motivation for using a balance board as the control device stems from Virtual Reality (VR) sickness; even small movements of your own body matching the motions seen on the screen decrease the sensory conflict between vision and vestibular organs, which lies at the heart of most theories regarding the onset of VR sickness. To test the hypothesis that the balance board as a control method would be less sickening than using joysticks, we designed a user study (N=32, 15 women) in which the participants drove a simulated differential drive robot in a virtual environment with either a Nintendo Wii Balance Board or joysticks. However, our pre-registered main hypotheses were not supported; the joystick did not cause any more VR sickness on the participants than the balance board, and the board proved to be statistically significantly more difficult to use, both subjectively and objectively. Analyzing the open-ended questions revealed these results to be likely connected, meaning that the difficulty of use seemed to affect sickness; even unlimited training time before the test did not make the use as easy as the familiar joystick. Thus, making the board easier to use is a key to enable its potential; we present a few possibilities towards this goal.

This paper identifies a new phenomenon: when users interact with simulated objects in a virtual environment where the user is much smaller than usual, there is a mismatch between the object physics that they expect and the object physics that would be correct at that scale. We report the findings of our study investigating the relationship between perceived realism and a physically accurate approximation of reality in a virtual reality experience in which the user has been scaled down by a factor of ten. We conducted a within-subjects experiment in which 44 subjects performed a simple interaction task with objects under two different physics simulation conditions. In one condition, the objects, when dropped and thrown, behaved accurately according to the physics that would be correct at that reduced scale in the real world, our true physics condition. In the other condition, the movie physics condition, the objects behaved in a similar manner as they would if no scaling of the user had occurred. We found that a significant majority of the users considered the latter condition to be the more realistic one. We argue that our findings have implications for many virtual reality and telepresence applications involving operation with simulated or physical objects in small scales.

Realistic 3D virtual environments, such as existing city models, have the potential to be used in pervasive games as a passageway between physical and virtual. Smooth attention displacement and transitions between these two realities are largely unexplored in the context of pervasive gameplay. We conducted two field trials using a pervasive live action role playing game to study the effect moving between the virtual and the physical has on co-presence and memorability. Although differences in co-presence during gameplay were small, they highlight the subtleties in the social structuring of pervasive gameplay. Spatial similarity between the physical and virtual environments made the 3D virtual environments more memorable. We identify two important issues to consider in embedding virtual environments into pervasive games: structuring of social interactions and the spatial realism of the VEs.

Living labs are environments for acquiring user feedback on new products and services. Virtual environments can complement living labs by providing dynamic immersive setup for depicting change. This paper describes implementation of Virtual and Augmented Reality clients as an extension to a user involvement tool for an existing living lab. We conducted a user experience study with 14 participants to compare the clients. According to our study, the virtual reality client was experienced as innovative, easy to use, entertaining and fun. Whereas the augmented reality client was perceived playful and empowering.

In this video paper we report on our experiences of deploying a VR point at a public library for the purpose of educating library patrons on VR technology. The primary application offered at the VR point is called Virtual Library, a VR application developed specifically for the Oulu City Library. The Virtual Library application provides an immersive virtual interface into selected library services, as well as allows library patrons to browse literature recommendations inside genre-specific fantasy realms. Based on the observations of the first week weeks of deployment, the VR point and the Virtual Library are successful approaches for technology education in a public library.

In this demo paper we describe the development process and technical implementation of an interactive Virtual Reality (VR) application dubbed Virtual Library. The application utilizes consumer VR hardware and Unreal Engine to provide an immersive virtual interface to a physical library and its selected services, as well as browsing of literature content in aesthetic fantasy realms. The prototype is publicly available at the Oulu City Library.

We present an immersive VR interface for a public library where a mirror-world like virtual copy of the physical library is blended with imaginary virtual fantasy layers into a hybrid space for library content. The design of the system was guided by multi-stakeholder Participatory Design process involving library staff, library customers and researchers. The findings of the qualitative user evaluation of the prototype suggest that this kind of a VR interface is an exciting extension to a physical library, indicating the unlimited possibilities offered by the VR's ability to send the user into imaginary places.

In this study we compare two conditions of visual detail - modern graphics and detail reduction through cel-shading - in experiencing Cybersickness during virtual movement along a preprogrammed path within a scene depicting a real-world outdoor museum viewed with Oculus CV1. The Cybersickness experience was quantified with the Fast-Motion-Sickness (FMS) scale and the Simulator Sickness Questionnaire (SSQ). We found weak evidence for realistic graphics being more sickness-inducing. Also, FMS scores peaked whenever a participant was entering a building.

In this paper we explore immersive street-level integration of social media content into collaborative virtual 3D city environments on two levels: i) public, where the virtual environment is populated with relevant social media content (e.g. Twitter and Facebook feeds of shops, non-governmetal organizations, the City organization); and ii) personal, where the virtual user, through his/her avatar, is able to access his/her personal social media feeds while immersed in the virtual city. We conducted a qualitative anticipated user experience study with 14 participants in four focus groups, who were asked to create designs of how they imagined social networking services could be integrated into virtual city environments. Further, participants were asked to comment on two visual concepts created by researchers. Results show that people appreciate the concept of having virtual cities populated with up-to-date content from social media services, but linking their own social media accounts is a more complex issue.

Energy efficiency is a powerful measure for promoting sustainability in technological evolution and ensuring feasible battery life of mobile end-user devices. Peer-to-peer technology provides decentralized and self-organizing, but also energy-inefficient technology for distributing content between devices in networks that scale up almost infinitely. The dissertation [1] summarized in this paper makes four contributions towards enabling energy-aware peer-to-peer networking in mobile environments: 1) an empirical study for understanding the energy consumption characteristics of radio interfaces and typical composition of traffic in peer-to-peer networks, 2) a model for estimating the energy consumption of a mobile device with different traffic profiles, 3) a model for energy-aware load monitoring of mobile peer nodes, and 4) a mobile agent based virtual peers concept for energy-aware sharing of peer responsibilities between peer nodes in a subnet. The results give valuable insight into implementing energy-efficient peer-to-peer systems in mobile environments.

We present a mixed-methods study aimed at assessing artists' experiences of a digital art exhibition service, called StreetGallery, on a network of interactive displays situated in public urban locations. We ground our analysis using survey responses and in-depth interviews of artists who have exhibited their art in StreetGallery over the years. Findings from these studies indicate that the artists highly value StreetGallery's open and egalitarian access to art, and its contribution towards fusing novel digital technologies and art in public urban spaces. We conclude that platforms such as StreetGallery have the potential to challenge traditional paradigms of art gallery practices and public urban spaces as a stage for consumption and commerce.

We describe an interactive digital art application deployed at a university campus with the goal of investigating participants' initial experiences of bridging two realities through 3D artwork in a hybrid reality space. The underlying purpose of the installation is to bring liveliness and increased social interaction to both the virtual and the physical world. We used the HTC Vive and a 3D painting program (Google Tilt Brush) for the creation of the artwork. After creation, the artworks were transferred to an immersive virtual mirror world, in our case a version of our university campus, using an export tool. Results from an initial user study with 32 participants suggest that people found our system attractive, and there was only slight difference in how much they enjoyed seeing their work in the Tilt Brush view versus the virtual campus gallery view.

Here we propose an interactive system to augment creative design thinking using networks of concepts in a virtual reality environment. We discuss how to augment the human capacity to be creative through dynamic suggestions providing new and original ideas, based on specific semantic network characteristics. We outline directions to explore the structures of the concept network and their connection to creative concept generation. It is expected that augmented creative thinking will allow the user to have more original ideas and thus be more innovative.

This paper presents the current status of work-in-progress in developing Ghost Hunters that is targeted to explore the possibilities of incorporating gesture control and ambient lighting in a mobile augmented reality game played with smart glasses. We present the design and implementation of the current prototype, together with a small feasibility evaluation of battery consumption and gesture control.

In this paper we present early results from our investigation in whether the utilization of 3D objects brings added value in public transportation visualization systems. We describe the implementation of our easily generalizable WebGL based system titled "Virtual Bus", and the results of a preliminary evaluation. The evaluation consists of a small user study where the Virtual Bus system was compared to visualization capabilities of a commercial PTS information system. The results of the evaluation imply potential in 3D visualizations.

We introduce evaluation probes for conducting emic, experiential evaluation of urban technologies "in the wild" without direct researcher presence. We commence with a thorough discussion and analysis of the original cultural probes, used by Gaver, Dunne and Pacenti to gain design inspiration, and their subsequent variations. We develop the concept of evaluation probes through careful re-conceptualization and application of the cultural probes in three successive studies conducted in the wild. We recount and reflect on our use of evaluation probes and discuss their merits and limitations in experiential emic evaluation.

We present a location based mixed reality game called Street Art Gangs that we have developed to explore the playful appropriation of the hybrid reality comprising of a city center and its detailed virtual replica represented as a 3D virtual model. In the real streets SAG is played with a mobile phone app that allows tagging predefined locations around the city to claim their ownership and busting nearby players of competing gangs. The virtual game world is viewed with a PC app that allows observing the current owners of taggable locations, the locations of other players, and the locations of patrolling virtual policemen busting players. We have developed two incremental versions of SAG that have been evaluated with tournaments in the wild. We conceptualize the findings of the tournaments with de Souza e Silva's theoretical framework for hybrid reality games. Our findings suggest that players preferred to play the game on real city streets while the added value of the virtual game world remained marginal. The size of the game both in terms of area and the number of taggable locations turned out to have a major impact on gameplay.

The interaction process with interactive public displays can be viewed as a set of interaction phases. In this paper we report a wizard-of-Oz study that explores the last two phases: 1) subtle interaction, where users can interact with the display through gestures or movement, and 2) direct interaction, when users interact with the display by directly manipulating it through e.g. a touch-screen interface. We investigate the effect of these two interaction phases on at-glance information acquisition, and demonstrate that the presentation of such at-glance information items can help shorten interaction times during the direct interaction phase.

We propose a novel way to approach the research and design of urban ICT, namely, climate sensitive urban computing. This approach considers the climatic patterns, weather conditions and people's adaptations to them on the level of everyday practices. Our theoretical and methodological foundations lay in the fields of cultural anthropology, architecture, and HCI. First, we present a multidisciplinary discussion of prior works relating to technology, weather and climate conditions. Secondly, through two empirical, mostly qualitative data sets, we demonstrate the vast impact weather and climate have on young adults' ICT use at our research site located in Northern Finland. Thirdly, based on the theoretical discussion and findings from the real-world studies, we argue that climate sensitive thinking should be part of the design of urban ICT, and outline some central design challenges.

In this paper, we propose a novel architecture, called ADHT, that allows the participation of wireless and constrained-capacity M2M devices in a P2P overlay without compromising their battery life. The approach makes P2P-based networking feasible in scenarios where dedicated super-peer nodes are not available or not feasible to use, e.g. when all the participating nodes in a subnet are constrained devices. The concept is based on sharing the peer responsibilities among the nodes within the same subnet using mobile agent-based virtual peers. The mobile agent-based approach enables on-the-fly configurations to further reduce energy consumption in the subnet nodes during runtime. The presented mobile agent composition is both programming language- and platform-independent. Therefore it inherently enables heterogeneous platforms, from the low-power resource-constrained embedded networked devices to the cloud platforms, to operate as the P2P peer. We analyze the power consumption characteristics of the mobile agent-based approach by comparing it with alternative architectures with a numerical analysis.

In this paper we study traffic patterns in a large municipal WiFi network and in particular those of the most bandwidth hungry application, viz. YouTube, for which we provide a detailed analysis of demand in different geographical areas and over time. We consider the possibilities to reduce network traffic and increase Quality of Experience (QoE) by serving repeated requests for YouTube videos from caches placed either at the network head end, at the wireless access points, or in the user devices. Our data confirms that a significant part of the YouTube traffic can be served by such devices and that there exists a potential to optimize caching performance by exploiting the content demand locality. We also discover a previously unknown pattern of periodicity in content demand and present a simple example of how to exploit this in cache design.

We report a pre-study and a three-week in-the-wild deployment of a non-moderated interactive public display prototype designed as a communication extension for an established community. A pre-study was conducted to map existing practices in order to ground the design. We explore the adoption process of the display prototype as well as rhythms of usage. We discuss findings related to extensions of presence within the community, the impact of the display on the community's activities, as well as aspects of appropriation and co-design. We illustrate how the display was used to extend one's presence within the community in addition to existing means of communication. This opens up new design possibilities when social dynamics are carefully negotiated.

Most studies take for granted the critical first steps that prelude interaction with a public display: awareness of the interactive affordances of the display, and enticement to interact. In this paper we investigate mechanisms for enticing interaction on public displays, and study the effectiveness of visual signals in overcoming the 'first click' problem. We combined 3 atomic visual elements (color/greyscale, animation/static, and icon/text) to form 8 visual signals that were deployed on 8 interactive public displays on a university campus for 8 days. Our findings show that text is more effective in enticing interaction than icons, color more than greyscale, and static signals are more effective than animated. Further, we identify gender differences in the effectiveness of these signals. Finally, we identify a behavior termed "display avoidance" that people exhibit with interactive public displays.

The Internet of Things presents the user with a novel means of communicating with the Web world through ubiquitous object-enabled networks. Cloud Computing enables a convenient, on demand and scalable network access to a shared pool of configurable computing resources. This paper mainly focuses on a common approach to integrate the Internet of Things (IoT) and Cloud Computing under the name of CloudThings architecture. We review the state of the art for integrating Cloud Computing and the Internet of Things. We examine an IoT-enabled smart home scenario to analyze the IoT application requirements. We also propose the CloudThings architecture, a Cloud-based Internet of Things platform which accommodates CloudThings IaaS, PaaS, and SaaS for accelerating IoT application, development, and management. Moreover, we present our progress in developing the CloudThings architecture, followed by a conclusion.

One challenging problem in Machine-to-Machine (M2M) applications is to efficiently discover the resources provided by a huge number of heterogeneous devices. This paper proposes distributed resource discovery architecture (DRD) for M2M applications. The DRD supports heterogeneous devices in resource description registration and discovery of resource value. It achieves interoperability among heterogeneous devices in disparate networks and enables resource access from the Internet. In the DRD, a resource registration component is designed for storing resource descriptions, a resource discovery component is designed to retrieve resource values on behalf of clients after getting address information by looking up resource descriptions. The DRD utilizes a peer-to-peer overlay to distribute workload and avoid single point of failure. A real-world prototype is implemented and verified with a simple demo. Preliminary evaluation on response time of resource discovery is provided.

This paper summarizes the 2nd UBI Challenge that invited the global R&D community to design, implement, deploy and evaluate novel applications and services in real world setting atop the open urban computing testbed in Oulu, Finland. The paper first recaps the 1st UBI Challenge and then provides a procedural description of the 2nd UBI Challenge. The paper concludes with a discussion on issues related to participation in the UBI Challenge.

We demonstrate interoperable mobile agents for language- and platform-independent wireless sensor network programming, with low-power resource-constrained embedded devices as static nodes and Android-based smartphones as mobile nodes, over disparate networks: 6LoWPAN and Wi-Fi. Representational state transfer architectural principles are applied in agent composition, control and migration and exposing the system resources to the Web: the devices, agents, sensor data, tasks and data processing results. The adaptable agent composition includes the task code in any programming language, the agent migrates according to a resource list and the state, i.e. the intermediate task result, represents the agent as a system resource. Mobile agents are then utilized in two tasks: first to collect light sensor data cooperatively in location, saving the mobile node battery whenever possible, and secondly the magnetometer sensor data with the scanned Wi-Fi access points' signal strength is used to detect groups of mobile nodes moving in the same direction in real-time.

We demonstrate interoperable mobile agents to integrate Internet of Things and wireless sensor networks with resource-constrained low-power embedded networked devices. We introduce adaptable composition for the mobile agent, complying with the Representational State Transfer principles, which are then used for agent migration, controlling the agent and exposing the data, system resources, tasks and services, to the Web. We gather requirements for the system and heterogeneous networked devices and present an application programming interface to enable mobile agents in these systems. The agents are demonstrated in a real-world prototype with smartphones and embedded networked devices, where we utilize a proxy component to expose system resources to the Web for human-machine interactions. Spanning over disparate networks and protocols, the proxy translates messages including the agent composition, between HTTP and Constrained Application Protocol. Lastly, we suggest an evaluation method for the agent communication and migration costs, considering the different types of system resources and utilization.

Machine-to-Machine (M2M) communications emerge to achieve ubiquitous communications among all the networked devices. One challenging problem in M2M applications is to discover the resources provided by the devices efficiently. This challenge arises from two perspectives: (1) a large number of heterogeneous devices co-exist and most of them are constrained devices (e.g., limited processing capability), (2) different communication protocols are utilized to get access to different types of resources provided by the devices (e.g., humidity information provided by a sensor). This paper proposes distributed resource directory architecture for M2M applications, referred to as DRD4M. The DRD4M supports heterogeneous devices using HTTP and CoAP protocols for resource registration and lookup. This enables the interoperability among heterogeneous devices and resource access to constrained devices from disparate network including the Internet. The DRD4M introduces two components: a resource registration component for registering resources and a resource lookup component with caching functionality for handling resource lookup with filtering. A peer-to-peer (P2P) overlay is introduced in DRD4M to connect resource peers to avoid single point of failure. A real-world prototype is implemented and is verified with a demo application. Preliminary performance evaluation in terms of response time of resource lookup is provided.

Open mobile platforms such as Android currently suffer from the existence of multiple versions, each with its own peculiarities. This makes the comprehensive testing of interactive applications challenging. In this paper we present Testdroid, an online platform for conducting scripted user interface tests on a variety of physical Android handsets. Testdroid allows developers and researchers to record test scripts, which along with their application are automatically executed on a variety of handsets in parallel. The platform reports the outcome of these tests, enabling developers and researchers to quickly identify platforms where their systems may crash or fail. At the same time the platform allows us to identify more broadly the various problems associated with each handset, as well as frequent programming mistakes.

We report two one-month-long field trials where Bluetooth access points deployed around Oulu, Finland, were employed to attempt to push unsolicited multimedia marketing messages to bypassing mobile devices that had their Bluetooth on and visible. The logs involving ~65000 unique discovered devices of real users show that only 0.12% of the ~650000 transmission attempts were successful. On average, 1.1% of the devices received the message and 3.3% of the owners of these devices signed up to the marketing campaign. These statistics characterize the efficiency of 'carpet bombing' type of proximity marketing realized with the current Bluetooth technology without any support mechanisms.

We present a multi-stakeholder study of the value propositions that various actors associate with an open community testbed of interactive public displays. Our short-term objective is to enhance the current business model that generates revenue for covering the operational expenses of the tested. Our long-term objective is to establish an economically sustainable lifecycle model for the testbed that is based on successful value co-creation by multiple stakeholders. The five-pronged study includes a questionnaire study of local citizens using the displays, an online survey to the members of a local business coalition, and interviews of municipality representatives, commercial customers and content providers. Our study shows that different actors associate a wide range of economic, functional, emotional and symbolic values with the testbed. Our findings also emphasize the importance of communication in creating and nurturing these perceived value propositions.

This paper introduces the UBI Challenge that challenged the global R&D community to design, implement, deploy and evaluate novel applications and services in real world setting atop an open urban computing testbed. The paper first provides a procedural description of the UBI Challenge and then discusses the outcome so far with a special focus on the various issues introduced by the real world setting.

We report a novel deployment of so-called UBI-hotspots in a city center to establish an ecosystem infrastructure for conducting diverse urban computing research and business in authentic urban setting. We focus on the value network of the hotspots where the commercial use of the hotspots generates revenue for covering their operational expenses. The value network has been validated by a 12-month long operation, during which the hotspots and their services have been available to the general public on 24/7 basis.

In this paper, we suggest utilizing modern social networking services for building versatile applications for interactive public displays. We demonstrate the functionality and potential of this approach by presenting a set of services deployed on top of a network of public displays, utilized in a longitudinal study in an authentic city setting. We further propose utilizing users' personal online profiles for building personalized and appealing public social services, and suggest that this may enhance the attractiveness of interactive public displays. Results of this study indicate that using interactive public displays is inherently a social event, and that services supporting group use and sociality succeed in urban smart spaces.

In this paper we present a web-based framework for spatiotemporal screen real estate management of interactive public displays. The framework facilitates dynamic partitioning of the screen real estate into virtual screens assigned for multiple concurrent web applications. The framework is utilized in the implementation of so-called UBI-hotspot, which provides various information services via different interaction modalities including mobile. The framework facilitates seamless integration of third party web applications residing anywhere in the public Internet into the UBI-hotspot, thus catering for a scalable and open architecture. We report the deployment of a network of indoor and outdoor UBI-hotspots at downtown Oulu, Finland. The quantitative data on the usage of the UBI-hotspots implicitly speaks in favor of the practical applicability of the framework.

In this paper we suggest a conceptual architecture for music systems, designed to shift the control over a shared urban space to the users themselves, and also to encourage social interaction between co-located friends and strangers alike. We present UbiRockMachine, a prototype application designed to bring the communities of local, un-signed music producers and music consumers together. The application provides a two-way communications channel where the music producers make their creative content available to the people occupying a shared social space. These people democratically choose the music played in the shared public space and provide valuable feedback to the musicians by downloading and rating their content.

IP networks allow constructing versatile device configurations for multimedia streaming. However, the stochastic nature of the packet-switched data transmission may complicate IP-based implementations of some conventional applications such as analog wired transmission of synchronized multi-channel audio. This paper introduces a multimedia streaming system based on the synchronization of multiple playback clients as a dasiaswarmpsila. The proposed dasiaswarm synchronizationpsila mechanism is based on precise clock synchronization with the PTP protocol and adjusting the client-specific sampling rates according to the true playback rates of other clients. A streamlined version of the RTP protocol is employed to minimize playout delay. The proposed system is empirically evaluated in wired Ethernet LAN and in wireless IEEE 802.11g LAN. The experimental results show that in the Ethernet network the proposed streaming system is able to achieve very precise synchronization.

We introduce BlueInfo, an open architecture for deploying Web services in WPAN hotspots for cost-free context-aware mobile access over Bluetooth. A BlueInfo hotspot either pushes subscribed services at desired intervals to registered devices (BlueInfo Push) or alternatively the user invokes a particular service by sending a simple keyword query to the hotspot (BlueInfo Pull). The BlueInfo hotspot requests the service from the origin server in the Internet and relays the response to the mobile device, possibly after adaptation for mobile viewing. The usability of BlueInfo Pull in comparison to a mobile phone browser is demonstrated with an empirical user evaluation conducted in a laboratory setting.

In this paper we suggest a conceptual architecture for music systems, designed to shift the control over a shared urban space to the users themselves, and also to encourage social interaction between co-located friends and strangers alike. We present UbiRockMachine, a prototype application designed to bring the communities of local, un-signed music producers and music consumers together. The application provides a two-way communications channel where the music producers make their creative content available to people occupying a shared social space. These people then democratically choose the music played in the shared public space and provide valuable feedback to the musicians by downloading and rating their content. We present findings from empirical user testing carried out in three separate locations, and outline directions for future work and further experiments.

This paper presents MobiToss, a novel application for creating and sharing mobile multimedia art with an off-the-shelf mobile phone equipped with built-in accelerometer sensors allowing gesture control. The user first takes a photo or captures a video with the phone and then using a 'throwing' gesture transfers the clip onto a large public display for instant viewing and manipulation by tilting the phone in different directions. The system augments the user-created clip with other items such as music or brand labels and the encoded clip is automatically sent back to the phone as a personal artefact of the event. The clip is also uploaded to a dedicated community website for sharing the created multimedia art with others. MobiToss could be deployed e.g. in clubs, pubs and concerts as a participatory VJ-tool. In addition to the design the paper presents the results of a preliminary user evaluation, which highlight the novel art experience provided by MobiToss.

We introduce panOULU Luotsi, a multi-device location-based information mash-up provided for the users of a large municipal wireless network. XML content in various forms, such as RSS/ATOM feeds from several content providers are automatically merged into a database using a flexible XML aggregator. It allows mapping different heterogeneous information feeds into the database without any changes to the application source code. The location of the user is estimated by identifying the WiFi access point to which the user's wireless device is currently connected. The information relevant to the user's current location is imposed on a map for a location-based browsing view, which allows the user to learn about nearby services, sites and events of interest.

This paper studies the design rationale and evaluation of an urban storytelling game called Story Mashup. In the game ubiquitous computing infrastructure is utilized to facilitate real-time interaction between mobile and web users. Textual stories written in the web by certain people are illustrated by other people taking matching photos with camera phones. Complete stories are then displayed on a large public display and on the web. To carry out a thorough empirical evaluation of the game design in a real world setting, the game was played in New York in September 2006 with 180 players and by people in the internet around the world. The results show that the adopted iterative design process succeeded in achieving the goals set for usability, user experience and game stimulation.

Interactive experiments on video retrieval systems need to address the problem of internal validity, i.e. how much the test users' experience affects the retrieval effectiveness. This paper compares the semantic retrieval performance of novice users and expert system developers. The test system utilizes cluster-temporal browsing, which combines chronological video structure and computation of similarities into single interface. Interactive experiments with eight test users were carried out in a database of ~80 hours of multilingual news video from TRECVID 2005 benchmark. A cluster-temporal browser was found to improve the retrieval effectiveness by 12% with novice system users. Expert users were able to achieve 18% better performance than the novice users. Additionally, manual search experiments demonstrated that search performance can be improved by 19-25% when a plain text search is supplemented with content-based features

In this paper, we test statistically the effect of content-based browsing in generic video retrieval. Using TRECVID 2004 and 2005 experiments, we demonstrate that content-based browsing improves retrieval over sequential queries and relevance feedback. Two user groups, novices and system developers have been used in the experiments on large and multilingual video collections. Novice users were found to achieve improvement in search effectiveness with cluster-temporal browsing by statistically significant amount. System developers did not have statistically significant difference between the different system configurations.

This paper studies the performance sensitivity of the variations in different factors on SNoW and SVM based face detection techniques. These factors include combinations of training set, pixel transitions in sliding window, pre-processing methods (rotation, scaling, light correction, masking filter), and bootstrapping in negative training patterns. It was found that performance of the two detection methods is significantly sensitive to these factors.

This paper presents a novel cross-layer design for providing service oriented architecture (SOA) in a mobile ad hoc network (MANET). In the design SOA service discovery is integrated into the ad hoc routing protocol underlying the MANET. We present a prototype implementation based on the optimized link state routing (OLSR) protocol, and its empirical evaluation.

This paper introduces a novel and creative approach for coupling multimedia art with a non-conventional distributed human-computer interface for multi-user interactive entertainment. The proposed MobiLenin system allows a group of people to interact simultaneously with a multi-track music video shown on a large public display using their personal mobile phones, effectively empowering the group with the joint authorship of the video. The system is realized with a client-server architecture which includes server-driven real-time control of the client UI to guarantee ease of use and a lottery mechanism as an incentive for interaction. Our analysis of the findings of an empirical user evaluation conducted in a true environment of use shows that the MobiLenin system is successful, addressing many of the challenges identified in the literature. The proposed system offers a new form of interactive entertainment for pubs and other public places, and the underlying architecture provides a framework for realizing similar installations with different types of multimedia content.

Mobility, context-awareness and payment combined provide a customer with a completely new setting of consuming services at any time and any place. We introduce SmartRestaurant service, which allows customers to use mobile devices for ordering and paying lunches from a nearby campus restaurant beforehand. Further, SmartRestaurant provides the restaurant with means of adjusting the sales with production capacity and prior knowledge of upcoming orders. We present a user evaluation of the system in form of a field trial in the real environment of use.

The paper describes cluster-temporal browsing of news video databases. Cluster-temporal browsing combines content similarities and temporal adjacency into a single representation. Visual, conceptual and lexical features are used to organize and view similar shot content. Interactive experiments with eight test users have been carried out using a database of roughly 60 hours of news video. Results indicate improvements in browsing efficiency when automatic speech recognition transcripts are incorporated into browsing by visual similarity. The cluster-temporal browsing application received positive comments from the test users and performed well in overall comparison with interactive video retrieval systems in TRECVID 2003 evaluation.

Advertising on mobile devices has large potential due to the very personal and intimate nature of the devices and high targeting possibilities. We introduce a novel B-MAD system for delivering permission-based location-aware mobile advertisements to mobile phones using Bluetooth positioning and Wireless Application Protocol (WAP) Push. We present a thorough quantitative evaluation of the system in a laboratory environment and qualitative user evaluation in form of a field trial in the real environment of use. Experimental results show that the system provides a viable solution for realizing permission-based mobile advertising.

The advanced smartphones entering the mass market are capable of playing audio and video files back, which paves the way for new types of rich mobile multimedia services. However, these services impose high data rate requirements on the wireless link, which can not necessarily be satisfied with the current mobile phone networks. This can be compensated with a wireless personal area network based for example on Bluetooth connectivity, or with a wireless local area network. This paper presents a case study demonstrating complementary distribution of static and dynamic multimedia content with Bluetooth equipped WPAN service points, a wireless local area network and mobile phone networks. The empirical evaluation conducted in the real environment of use shows that the proposed service is meaningful with commercial potential.

Presents a theoretically very simple, yet efficient, multiresolution approach to gray-scale and rotation invariant texture classification based on local binary patterns and nonparametric discrimination of sample and prototype distributions. The method is based on recognizing that certain local binary patterns, termed "uniform," are fundamental properties of local image texture and their occurrence histogram is proven to be a very powerful texture feature. We derive a generalized gray-scale and rotation invariant operator presentation that allows for detecting the "uniform" patterns for any quantization of the angular space and for any spatial resolution and presents a method for combining multiple operators for multiresolution analysis. The proposed approach is very robust in terms of gray-scale variations since the operator is, by definition, invariant against any monotonic transformation of the gray scale. Another advantage is computational simplicity as the operator can be realized with a few operations in a small neighborhood and a lookup table. Experimental results demonstrate that good discrimination can be achieved with the occurrence statistics of simple rotation invariant local binary patterns.

Recently, a nonparametric approach to texture analysis has been developed, in which the distributions of simple texture measures based on local binary patterns (LBP) are used for texture description. The basic LBP encodes 256 simple feature detectors in a single 3/spl times/3 operator. This paper shows that a properly selected subset of patterns encoded in LBP forms an efficient and robust texture description which can achieve better classification rates in comparison with the whole LBP histogram. Experiments on classification of textures from the Columbia-Utrecht (CURET) database demonstrate the robustness of the approach.

This paper benchmarks the simple local binary pattern (LBP) approach in the supervised texture segmentation problems of the recent comparative study of Randen and Husoy (1999). A multi-predicate version of LBP is proposed, making our approach even more powerful for images containing textures at multiple scales.

This paper presents a new approach to provide computer telephony integration for mobile users and distribute services over the hybrid network domain. A new multimedia processing paradigm is presented in the form of a distributed, agent-based architecture, called 'Distributed Agent Network', DAN, together with example services. The proposed architecture is designed to support user and data mobility, media integration, and universal multimedia messaging. We provide a consistent distributed service platform and dedicated media processing algorithms for mobile multimedia conferencing, mobile messaging and related services. New agent-based techniques are introduced to deal with the abstraction of roles, embedding of media and to overcome the current obstacles in one-to-one and multiparty conferences. Techniques for novel software mobility are presented. The main benefits include scalability of services over different media types, and the ability to use agent intelligence in distributed communications for carrying out dedicated missions. The proposed architecture is demonstrated with a case study of an Internet video call center.

A multichannel approach to texture description is proposed by approximating joint occurrences of multiple features with marginal distributions, as 1D histograms, and combining similarity scores for 1D histograms into an aggregate similarity score. A stepwise feature selection algorithm is used to choose the best feature combination in a particular dimension. In classification experiments with Brodatz textures and MeasTex test suites the proposed method performs favorably compared to GLCM, Gabor and GMRF features.

This paper considers a pattern recognition approach to accurate camera-based color measurements. The performances of Swain and Ballard's color indexing method based on 3-dimensional histograms and of a simplified version based on three 1-dimensional histograms are evaluated using three common color spaces and two sets of test images.

Texture analysis has many areas of potential application in industry. The problem of determining composition of grain mixtures by texture analysis was recently studied by Kjell. He obtained promising results when using all nine Laws' 3 × 3 features simultaneously and an ordinary feature vector classifier. In this paper the performance of texture classification based on feature distributions in this problem is evaluated. The results obtained are compared to those obtained with a feature vector classifier. The use of distributions of gray level differences as texture measures is also considered.

This paper evaluates the performance both of some texture measures which have been successfully used in various applications and of some new promising approaches. For classification a method based on Kullback discrimination of sample and prototype distributions is used. The classification results for single features with one-dimensional feature value distributions and for pairs of complementary features with two-dimensional distributions are presented.

Pietikainen and Rosenfeld (1982) introduced a class of texture measures based on first-order statistics derived from edges in an image. the objective of this paper is to evaluate the performance of these measures and some new edge-based texture measures using two different types of data sets: images taken from the Brodatz album and images from a practical wood surface inspection problem. The results obtained for edge-based measures are compared to those obtained by popular second-order texture measures and tonal features. The role of the classifier on the performance is also studied by comparing the results obtained for three parametric classifiers and for a nonparametric k-nearest neighbor classifier. The results indicate that edge-based approaches are very promising for surface inspection problems, because they are relatively simple to compute and have performed very well in experiments.>