Published papers

In this research, we propose a software model for the dynamic distribution of software components across a wide-area network, and we provide a software environment to realize the proposed model. In the dynamic distributed software model, software modules can autonomously migrate among computers. This feature allows dynamic distributed software to have the advantage of dynamic load balancing, fault tolerance, scalability, optimization of computing environment, and the processing support for small-size portable devices. Moreover, we designed and implemented a dynamic distributed software toolkit named "Meta Space".

This paper presents the design and implementation of information browsing support system transparent in devices and services, tranService. It translates the types of media in consideration of characteristic of devices and services. When a request for information is received from the client, it is altered to suit the format of the service. The information received from the service, in turn is altered to suit the user's request, and the information of the surrounding environment. Thus, the users can browse various information without any additional application, and service providers can provide information without consideration on users and devices.

This paper presents the design and implementation of information browsing support system transparent in devices and services, tranService. It translates the types of media in consideration of characteristic of devices and services. When a request for information is received from the client, it is altered to suit the format of the service. The information received from the service, in turn is altered to suit the user's request, and the information of the surrounding environment / Thus, the users can browse various information without any additional application, and service providers can provide information without consideration on users and devices.

© Copyright is held by the owner/author(s). In this research, we propose a system that allows one to find a hidden spot that is scenic, yet unpopulated, with the intention of improving the satisfaction of one's trip. These hidden spots are not yet noted in the existing tourism services, however can provide a new place for the tourists to discover. We developed an application as a prototype to analyze and pinpoint hidden spots by using venue data from Foursquare [1]. We acquired 19,705 data around Tokyo and calculated the relative hiding spot degree. Thus, we made it possible to provide users with hidden spot information from smartphone application.

© 2018 Elsevier B.V. Human attention has bottlenecked today's ubiquitous computing environment where users are consuming increasing amounts of information from numerous applications and services. Since the system-to-user provision of information is becoming more proactive, mainly via push notifications that often cause interruption at the users’ side, attention management is becoming very important. Despite the many existing studies concerned with detecting opportune moments to present such push information to the users (in a way that preserves the user's attention and lowers their cognitive load and frustration), there is little evaluation of such systems in the real-world production environments. Overlooked areas of study also include the examination of real users and notification contents. In this paper, we present various results from the first extensive evaluation on user's interruptibility and engagement in the real-world environment with a market-leading smartphone application that boasts a large number of users, including real notification content on the application. Following our previous mobile-sensing and machine learning-based interruptibility estimation approach, which was an effective study in its own right (Okoshi et al., 2015 [18,19]), we embedded a logic with the same approach in the “Yahoo! JAPAN” Android app (one of the most popular applications on the national market). The results from our large-scale in-the-wild user study (that included more than 680,000 users and spanned three weeks) indicate that, in most cases, delaying the notification delivery until an interruptible moment is detected is beneficial to users. The practice results in significant reduction of user response time (49.7%) when compared to delivering the notifications immediately. We observed a higher number of notifications opened in our system and constant improvement in user engagement levels throughout the entire study period. We also observed differences in click rates among different days and time among users with different attributes (e.g., age, gender, and occupation). Additional evaluation of our revised system, which can train and distribute different models for weekdays and weekends, improved the click rates during weekends. This negated the performance degradation previously observed during weekends.

© 2018 Copyright held by the owner/author(s). Publication rights licensed to ACM. In the advancing ubiquitous computing, users are increasingly confronted with a tremendous amount of information proactively provided via notifications from versatile applications and services, through multiple devices and screens in their environment. The human's attention is becoming a new significant bottleneck. Further, the latest computing trends with emerging new devices including versatile IoT devices, and contexts, such as smart cities and vehicles, are even accelerating this situation. In such situations, “attention management”, including attention representation, sensing, prediction, analysis, and adaptive behavior in the computer systems, are needed in our computing system. Following last years' successful UbiTtention 2016 and UbiTtention 2017 workshops with up to 50 participants, the UbiTtention 2018 workshop brings together researchers and practitioners from academy and industry to explore the management of human attention and notifications with versatile devices and smart situations to overcome information overload and overchoice.

In the advancing ubiquitous computing where users have been having an increasing amount of push-style information provision from lots of intelligent proactive services, detecting the users' current attentional status and/or in-terruptibility has been a significant issue. In our previous study[7] on interruptibility detection in "Yahoo! JAPAN" real world product for 21 days with more than 680,000 users, the result showed significant lower user response time in exchange for notification delivery delay for about 4 minutes on average. In this paper, we further analyze the features in the interruptibility detection model trained and updated during this study in nightly basis for 21 days and report the results. Copyright held by the owner/author(s).

© 2016 IEEE. This paper proposes ''SmileWave, a system for revealing smile-based emotional contagion, propagation effect of the similar emotion through smiley facial expression, on the social network where users interact each other through web-based user interface rather than in-person interaction. SmileWave is a picture-based networking service and detects the change of smile degree when the user looks at posted smile images of others. Our extensive user study with 50 participants for 30 days confirmed the emotional contagion effect on SmileWave. Users' smile degree improved by 27% when the user looked at posted smile images. The result also proved that there is a stronger effect on smile-based emotional contagion when the examinee and the person in the image are in close relationship.

© 2017 Copyright held by the owner/author(s). We propose "SmileWave", the first selfie social networking service to reveal the existence of emotional cognation through smiling selfies on the social network. We conducted multiple rounds of in-the-wild user studies with 86 cumulative total users for total duration of 5 weeks. Throughout the entire study, we confirmed the occurrence of smile-based emotional contagion over social network, not only in the momentary duration but in longer term period.