This paper describes a 10-month trial of a mobile learning organiser, developed for use by university students. Implemented on a wireless-enabled Pocket PC hand-held computer, the organiser makes use of existing mobile applications as well as tools designed specifically for students to manage their learning. The trial set out to identify the most-used tools for such a learning device and their patterns and problems of usage. The primary uses of the organiser were communication, time-management and access to content. No single application took precedence. The results from an analysis of questionnaire surveys and focus groups indicate that there was a demand for institutional support of mobile learning, in particular to provide course content and timetabling information. Wireless connectivity was crucial to the usefulness of the organiser. Usability issues relating to the hardware and software had considerable impact on the students' usage and satisfaction with the system.

For a client-server based view-dependent rendering system, the overhead of view-dependent rendering and the network latency are major obstacles in achieving interactivity. In this paper, we first present a multiresolution hierarchy traversal management strategy to control the overhead of view-dependent rendering for low-capacity clients. Then we propose a predictive parallel strategy to overcome the network latency for client-server based view-dependent multiresolution rendering systems. Our solution is to make the client process and the server process run in parallel, using the rendering time to cover the network latency. For networks with long round-trip times, we manage to overlap the network latency for one frame with the rendering time for multiple frames. View-parameters prediction is incorporated to make the parallelism of the client and the server feasible. In order to maintain an acceptable view-dependent rendering quality in the network environment, we develop a synchronization mechanism and a dynamic adjustment mechanism to handle the transient network slowdowns and the changes of the network condition. Our experimental results, in comparison with the sequential method, show that our predictive parallel approach can achieve an interactive frame rate while keeping an acceptable rendering quality for large triangle models over networks with relatively long round-trip times.

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