Daigo Taguchi

Design strategies for scenario-based hypermedia: description of its structure, dynamics, and style

This paper describes design strategies for scenariobased hypermedia, which presents media composite nodes according to timed scripts. In order to translate an author’s story into timed scripts within a hypermedia framework, we present a design model with four different levels of scenario specifications. In these levels an author specifies details of 1) global structure described as the hierarchy of composite nodes with sequencing relationship between them, 2) detailed structure of a composite node described as a set of subnodes and navigation flow between them, 3) content specification of multimedia data, and 4) time and spatial presentation style of media data included in each node. Design strategies based on the model were applied to the authoring of a CD-ROM based English listening course for Japanese students. The design work was accomplished as a joint project with English teachers, and our scenario-based hypermedia system, Videobook, was used as the authoriug platform. This paper reports the details of the design strategies in each level and discusses how they made the authoring efficient while promoting the quality of the course.

A rule-based RFID tag system using ubiquitous chips

Because of the recent development of radio frequency identification (RFID) technologies, various systems for RFID tags have been proposed. Since RFID tags only have a simple function, i.e., sending data, they can be available for various purposes. Accordingly, by customizing RFID tag systems, we can expand their applications. However, previous systems have been usually proposed for one special purpose only. In this paper, we propose a rule-based RFID tag system using ubiquitous chips. Our previously proposed ubiquitous chips are rule-based I/O control devices. By applying rule-based principles, we can easily customize the RFID tag system and can construct flexible, scalable, and easy exploitable systems.

A Wireless Dual-Link System for Sensor Network Applications

A reduced-power-consumption wireless ad-hoc multi-hop network system, the dual-link system,is been developed, using the following two technologies: Dual-link communication, which handles two different frequency bands, achieves low-power data transmission through independent optimum settings of both operation periods and communication distances for each band. The selection of frequency bands and operation settings depends on both the data sizes and communication intervals defined for individual applications. This dual-link communication is applicable to various kinds of intermittent communications. A vine-tree network topology that offers low addressing-bit counts and results in low packet-error rates even in low transmission-power communications. Since the topology does not require a routing table for individual nodes, hardware complexity can be kept to a minimum.