Inseok Hwang

MobyDick: an interactive multi-swimmer exergame

The unique aquatic nature of swimming makes it very difficult to use social or technical strategies to mitigate the tediousness of monotonous exercises. In this study, we propose MobyDick, a smartphone-based multi-player exergame designed to be used while swimming, in which a team of swimmers collaborate to hunt down a virtual monster. In this paper, we present a novel, holistic game design that takes into account both human factors and technical challenges. Firstly, we perform a comparative analysis of a variety of wireless networking technologies in the aquatic environment and identify various technical constraints on wireless networking. Secondly, we develop a single phone-based inertial and barometric stroke activity recognition system to enable precise, real-time game inputs. Thirdly, we carefully devise a multi-player interaction mode viable in the underwater environment highly limiting the abilities of human communication. Finally, we prototype MobyDick on waterproof off-the-shelf Android phones, and deploy it to real swimming pool environments (n = 8). Our qualitative analysis of user interview data reveals certain unique aspects of multi-player swimming games.

High5: promoting interpersonal hand-to-hand touch for vibrant workplace with electrodermal sensor watches

Interpersonal touch is our most primitive social language strongly governing our emotional well-being. Despite the positive implications of touch in many facets of our daily social interactions, we find wide-spread caution and taboo limiting touch-based interactions in workplace relationships that constitute a significant part of our daily social life. In this paper, we explore new opportunities for ubicomp technology to promote a new meme of casual and cheerful interpersonal touch such as high-fives towards facilitating vibrant workplace culture. Specifically, we propose High5, a mobile service with a smartwatch-style system to promote high-fives in everyday workplace interactions. We first present initial user motivation from semi-structured interviews regarding the potentially controversial idea of High5. We then present our smartwatch-style prototype to detect high-fives based on sensing electric skin potential levels. We demonstrate its key technical observation and performance evaluation.

SymmetriSense: Enabling Near-Surface Interactivity on Glossy Surfaces using a Single Commodity Smartphone

Driven to create intuitive computing interfaces throughout our everyday space, various state-of-the-art technologies have been proposed for near-surface localization of a users finger input such as hover or touch. However, these works require specialized hardware not commonly available, limiting the adoption of such technologies. We present SymmetriSense, a technology enabling near-surface 3-dimensional fingertip localization above arbitrary glossy surfaces using a single commodity camera device such as a smartphone. SymmetriSense addresses the localization challenges in using a single regular camera by a novel technique utilizing the principle of reflection symmetry and the fingertips natural reflection casted upon surfaces like mirrors, granite countertops, or televisions. SymmetriSense achieves typical accuracies at sub-centimeter levels in our localization tests with dozens of volunteers and remains accurate under various environmental conditions. We hope SymmetriSense provides a technical foundation on which various everyday near-surface interactivity can be designed.

My Being to Your Place, Your Being to My Place: Co-present Robotic Avatars Create Illusion of Living Together

People in work-separated families have been heavily relying on cutting-edge face-to-face communication services. Despite their ease of use and ubiquitous availability, experiences in living together are still far incomparable to those through remote face-to-face communication. We envision that enabling a remote person to be spatially superposed in ones living space would be a breakthrough to catalyze pseudo living-together interactivity. We propose HomeMeld, a zero-hassle self-mobile robotic system serving as a co-present avatar to create a persistent illusion of living together for those who are involuntarily living apart. The key challenges are 1) continuous spatial mapping between two heterogeneous floor plans and 2) navigating the robotic avatar to reflect the others presence in real time under the limited maneuverability of the robot. We devise a notion of functionally equivalent location and orientation to translate a persons presence into another in a heterogeneous floor plan. We also develop predictive path warping to seamlessly synchronize the presence of the other. We conducted extensive experiments and deployment studies with real participants.

Demo: Card-stunt as a Service: Empowering a Massively Packed Crowd for Instant Collective Expressiveness

Imagine a densely packed crowd that gathers to convey a common message, such as people in a candlelight vigil or a protest. We envision an innovation through mobile computing technologies to empower such a crowd by enabling them simply to hold their phones up and create a massive collective visualization on top of them. We propose Card-stunt as a Service (CaaS). CaaS is a service enabling a densely packed crowd to instantly visualize symbols using their mobile devices and a server-side service. The key challenge toward realizing an instant collective visualization is how to achieve instant, infrastructure-free, decimeter-level localization of individuals in a massively packed crowd, while maintaining low latency. CaaS addresses the challenges by mobile visible-light angle-of-arrival (AoA) sensing and scalable constrained optimization. It reconstructs relative locations of all individuals and dispatches individualized timed pixels to each one so that they can do their part in the overall visualization. We evaluate CaaS with extensive experiments under diverse reality settings as well as under synthetic workloads scaling up to tens of thousands of people. We deploy CaaS to 49 participants so that they successfully perform a collective visualization cheering up MobiSys.

CoMon+: A Cooperative Context Monitoring System for Multi-Device Personal Sensing Environments

Continuous mobile sensing applications are emerging. Despite their usefulness, their real-world adoption has been slow. Many users are turned away by the drastic battery drain caused by continuous sensing and processing. In this paper, we propose CoMon+, a novel cooperative context monitoring system, which addresses the energy problem through opportunistic cooperation among nearby users. For effective cooperation, we develop a benefit-aware negotiation method to maximize the energy benefit of context sharing. CoMon+ employs heuristics to detect cooperators who are likely to remain in the vicinity for a long period of time, and the negotiation method automatically devises a cooperation plan that provides mutual benefit to cooperators, while considering running applications, available devices, and user policies. Especially, CoMon+ improves the negotiation method proposed in our earlier work, CoMon [30], to exploit multiple processing plans enabled by various personal sensing devices; each plan can be alternatively used for cooperation, which in turn will maximize overall power saving. We implement a CoMon+ prototype and show that it provides significant benefit for mobile sensing applications, e.g., saving 27-71 percent of smartphone power consumption depending on cooperation cases. Also, our deployment study shows that CoMon+ saves an average 19.7 percent of battery under daily use of a prototype application compared to the case without CoMon+ running.

Designing Interactive Multiswimmer Exergames: A Case Study

The unique aquatic nature of swimming makes it difficult to use social or technical strategies to mitigate the tediousness of monotonous exercises. In this study, we propose the use of a smartphone-based multiplayer exergame named MobyDick. MobyDick is designed to be played while swimming, where a team of swimmers collaborate to hunt down a virtual monster. To this end, we take into account both human factors and technical challenges under swimming contexts. First, we perform a comparative analysis of a variety of wireless networking technologies in the aquatic environment and identify various technical constraints on wireless networking. Second, we develop a swimming activity recognition system to enable precise and real-time game inputs. Third, we devise a multiplayer game design by employing the unique interaction mode viable in an underwater environment, where the abilities of human communication are highly limited. Finally, we prototype MobyDick on waterproof off-the-shelf Android phones, and we deploy it in real swimming pool environments (n = 8). Our qualitative analysis of user interview data reveals certain unique aspects of multiplayer swimming games.

HomeMeld: Co-present Robotic Avatar System for Illusion of Living Together

Real-time remote interaction in work-separated families has become easier and richer by recent advances in mobile computing, yet it is still far from achieving a sense of living together. Imagine family members living apart are mutually co-present in each other’s home with their avatars that all the activities and movements are intelligently mirrored in the other’s living space. Such co-presence brings many pseudo living-together experiences, which are incomparable to those of today’s remote face-to-face communication. We develop an initial prototype, HomeMeld, a device-free self-mobile robotic system serving as a real-time, co-present avatar to create an illusion of living together. HomeMeld is built on top of a commercial telepresence robot hardware [1] and a CNN-based computer vision technique, letting a person be device-free at all times as like as she is at home. In this demo, we present the motivation behind our work, the end-to-end operation of HomeMeld, and the vision of giving a sense of living together to the family living apart.

Demo: Mobile Platform for Interactive Applications on Everyday Surfaces using a Single Commodity Smartphone

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4th ACM international workshop on mobile systems for computational social science

Smartphones and IoT devices are opening unprecedented opportunities to conduct social science studies in large-scale and longitudinal fashions. They enable unobtrusive collection of rich behavioral dataset such as physical sensory readings and on-line application use patterns. Also, smartphones can be used as 24/7 gateways for real-time intervention and feedback. Such powerful capabilities can facilitate larger-scale and timely social studies in a cost-effective way beyond traditional study methods such as self-reports, interviews, surveys, and observations under laboratory settings, etc. Many exploratory works have proven that mobile phones are a promising computational platform upon which we plan, develop, and conduct various experimental studies related to social science disciplines.