Data integrity constraints are fundamental in various applications, such as data management, integration, cleaning, and schema extraction. In this paper, we address the problem of finding inclusion dependencies on the Web. The problem is important because (1) applications of inclusion dependencies, such as data quality management, are beneficial in the Web context, and (2) such dependencies are not explicitly given in general. In our approach, we enumerate pairs of HTML/XML elements that possibly represent inclusion dependencies and then rank the results for verification. First, we propose a bit-based signature scheme to efficiently select candidates (element pairs) in the enumeration process. The signature scheme is unique in that it supports Jaccard containment to deal with the incomplete nature of data on the Web, and preserves the semiorder inclusion relationship among sets of words. Second, we propose a ranking scheme to support a user in checking whether each enumerated pair actually suggests inclusion dependencies. The ranking scheme sorts the enumerated pairs so that we can examine a small number of pairs for simultaneously verifying many pairs.

This paper addresses the problem of finding new locations of moved Web pages. We discuss why the content-based approach has a limitation in solving the problem and why it is important to exploit the knowledge on where to search for the pages.

PageChaser is a system that monitors links between Web pages and searches for the new locations of moved Web pages when it finds broken links. The problem of searching for moved pages is different from typical information retrieval problems. First, it is impossible to identify the final destination until the page is actually moved, so the index-server approach is not necessarily effective. Secondly, there is a large bias about where the new address is likely to be and crawler-based solutions can be effectively implemented, avoiding the need to search the entire Web. PageChaser incorporates a comprehensive set of heuristics, some of which are novel, in a single unified framework. This paper explains the underlying ideas behind the design and development of PageChaser.

We have developed a content construction system for collaborative learning based on a Wiki, a Web- based collaborative document authoring system. Requirements for such a tool are explained in three aspects (usability, content construction, easy and secure operation) and implemented accordingly. Experiment on usability of the system interface suggested improvement from a common Wiki.

The multimedia knowledge-based system (MMKS) is a knowledge-based system which provides a uniform environment for flexible human-machine communication using multiple media. MMKS has a knowledge representation method called predicate logic based on objects (PLOB) and an object-base defined based on a relational data model. PLOB is a first-order predicate logic in which every individual is regarded as an object, e.g. an integer, a string, and an image. The object-base is a collection of relations, and a relation is a set of tuples of objects. The management function of the object-base is defined based on SQL. The authors present the definition of MMKS and MMKS systems implemented on workstations.>

A Knowledge-based System with Audio-Visual Aids (KS/AV) is presented. KS/AV is a knowledge-based system that has multiple types of knowledge represented not only in symbols but in audio-visual (AV) images, and it provides an environment for humanmachine communication through AV media. We define a predicate logic based on objects for knowledge representation in KS/AV. It is a first order predicate logic in which every individual is regarded as an object. All of the individuals including AV images are regarded as objects. Their definitions are based on the class concepts of Smalltalk-80. AV image objects presented in this paper include not only simple video and graphic images, but also composite images that consist of several component images. This paper presents the KS/AV system developed on a small computer system with various AV equipment. As a case study, we developed a reading advisory system for children on KS/AV, which communicates with children through AV images and gives their favourite picture books.