Koji Yatani I am a Ph.D. candidate working with Prof. Khai N. Truong at Dynamic Graphics Project, University of Toronto. My research interests include Human-Computer Interaction (HCI) and ubiquitous computing, mainly developing novel user interaction techniques for various devices and user contexts. More specifically, I am interested in developing interaction techniques for mobile devices; understanding user practices and uncovering problems in difficult interaction contexts; building systems and tools to support user tasks in difficult interaction contexts; and developing novel hardware to support user interactions in mobile/ubiquitous computing environments.
		Contact Office: Bahen Center, 40 St. George St. Rm. 5170, Toronto, Ontario, M5S 2E4, CANADA e-mail: [my_first_name]@dgp.toronto.edu

SemFeel is a tactile feedback system which informs the user about the presence of an object where she touches on the screen and can offer additional semantic information about that item. Through multiple vibration motors that we attached to the back side of a mobile touch-screen device, SemFeel can generate different patterns of vibration, such as ones that flow from right to left or from top to bottom, to help the user interact a mobile device.

We investigate how and why Ubuntu contributors use diagrams in their work. Our study shows that diagrams are not actively used in many scenarios where they commonly would in co-located software development. We found differences in the use and practices of diagramming, their possible reasons, and developed design considerations for potential systems aimed at better supporting diagram use in OSS development.

Many mobile devices have touch-sensitive screens that people interact with using fingers or thumbs. However, such interaction is difficult because targets become occluded, and because fingers and thumbs have low input resolution. Recent research has addressed occlusion through visual techniques. However, the poor resolution of finger and thumb selection still limits selection speed. We address the selection speed problem through a new target selection technique called Escape. In Escape, targets are selected by gestures cued by icon position and appearance.

Although text entry in a mobile device has been heavily explored, most of the existing techniques have been studied only in a stationary scenario. Furthermore, we observed that the thumb of the non-dominant hand is available for the secondary input while a user is holding a device. Based on this observation, we designed a two-handed software keyboard with the stylus and the thumb. We compared four different stylus-based text entry techniques, including ours, in one stationary scenario and two mobile scenarios.

ARHunter is a computer-enhanced multi-player whack-a-mole game. It realizes an immersive entertainment environment combined with gestural input and location recognition technologies, which aims at increasing the level of players' engagement and excitement.

Toss-It provides intuitive information transfer techniques for mobile devices, by fully utilizing their mobility. With Toss-It, a user can send information from the user's PDA to other electronic devices with a “toss” or “swing” action, as the user would toss a ball or deals cards to others.

Musex supports children in learning and exploring collaboratively in a museum with PDAs (Personal Digital Assistant). Musex provides quizzes about exhibitions that are less interactive, such as explanatory panels and VTRs. Then, children pay their attention to these exhibitions natually. Through using Musex, children interact with exhibitions more actively and solve quizzes collaboratively.

Pi_book provides scaffolding contents about exhibitions in a museum with PDAs. Scaffolding contents in PDAs are interactive in order to attract children's attention to exhibitions and PDAs. Children can learn difficult scientific phenomina through interacting exhibitions and PDAs.