We present new alternative interfaces for zooming out on a mobile device: Bounce Back and Force Zoom. These interfaces are designed to be used with a single hand. They use a pressure-sensitive multitouch technology in which the pressure itself is used to zoom. Bounce Back senses the intensity of pressure while the user is pressing down on the display. When the user releases his or her finger, the view is bounced back to zoom out. Force Zoom also senses the intensity of pressure, and the zoom level is associated with this intensity. When the user presses down on the display, the view is scaled back according to the intensity of the pressure. We conducted a user study to investigate the efficiency and usability of our interfaces by comparing with previous pressure-sensitive zooming interface and Google Maps zooming interface as a baseline. Results showed that Bounce Back and Force Zoom was evaluated as significantly superior to that of previous research; number of operations was significantly lower than default mobile Google Maps interface and previous research.

We present a concept of using a movable background to navigate a caret on small mobile devices. The standard approach to selecting text on mobile devices is to directly touch the location on the text that a user wants to select. This is problematic because the user's finger hides the area to select. Our concept is to use a movable background to navigate the caret. Users place a caret by tapping on the screen and then move the background by touching and dragging. In this method, the caret is fixed on the screen and the user drags the background text to navigate the caret. We compared our technique with the iPhone's default UI and found that even though participants were using our technique for the first time, average task completion time was not different or even faster than Default UI in the case of the small font size and got a significantly higher usability score than Default UI.

We present a practical 3D reconstruction method that guarantees robust visual hull construction in real environments where segmentation errors and occlusion exist. The proposed method consists of foreground extraction and reliability-based shape-from-silhouette, and they are connected by the intra-/inter-silhouette reliabilities. In foreground extraction, all regions are classified into four categories based on their intra-reliabilities. Then the reliability-based shape-from-silhouette technique reconstructs a visual hull by carving a 3D space based on the intra-/inter-silhouette reliabilities. The proposed method provides a reliable visual hull in real environments without much increment of the system complexity compared with conventional systems.

The difficulty in finding the required information in hypermedia is widely recognized. The awareness in the computer mediated communication is also considered to be important for collaborative work. We propose a collaborative browsing system that supplements awareness information and try to resolve the difficulty of information retrieval by inquiring and monitoring other users, which are the actions frequently taken when a user is faced with a problem. In this study, we built and evaluated a prototype to see whether the system is effective. As the result of the evaluation, we found that the environment in which we can get information of WWW browsing awareness enables us to feel the others' presence and to grasp what the others are doing. Additionally, many subjects answered that they could browse the Web pages, which they did not know before. They also answered that they could increase the efficiency of browsing. We make a proposal about this collaboration browsing and present the results of experiments on its availability.