Current image database metadata schemas require users to adopt a specific text-based vocabulary. Text-based metadata is good for searching but not for browsing. Existing image-based search facilities, on the other hand, are highly specialised and so suffer similar problems. Wexelblat's semantic dimensional spatial visualisation schemas go some way towards addressing this problem by making both searching and browsing more accessible to the user in a single interface. But the question of how and what initial metadata to enter a database remains. Different people see different things in an image and will organise a collection in equally diverse ways. However, we can find some similarity across groups of users regardless of their reasoning. For example, a search on Amazon.com returns other products also, based on an averaging of how users navigate the database. In this paper, we report on applying this concept to a set of images for which we have visualised them using traditional methods and the Amazon.com method. We report on the findings of this comparative investigation in a case study setting involving a group of randomly selected participants. We conclude with the recommendation that in combination, the traditional and averaging methods would provide an enhancement to current database visualisation, searching, and browsing facilities

Information systems ontology is intended to facilitate interoperability among the many applications which are now becoming available on the Internet. In particular, it is intended to facilitate the development of intelligent agents which can automate a large part of the task of a user achieving some end employing multiple autonomous applications. A large number of ontologies exist supporting specific kinds of interoperation among selected, generally mutually aware, applications. The intent of the upper ontology movement is to develop an abstract description of what there is in the world, in an application-independent form, which can be used both to help build specific ontologies and to help in finding common ground among them. This paper argues that, for the purposes of information systems interoperation and the semantic web, application-independent upper ontologies are unlikely to be successful because of semantic heterogeneity. However, the paper argues for a distinction in upper ontologies between formal and material ontologies, based on analogies with concepts in Kant's synthetic a priori, and that formal ontologies whose focus is on how we see the world are more likely to be successfully developed in the absence of applications than are material ontologies, which attempt to catalog the world a priori. Categories and Descriptors: C.2.4 [Distributed Systems] Distributed Applications, Distributed Databases D.2.12 [Software Engineering] Interoperability—Data Mapping; H.3.5 [Information Storage and Retrieval] Online Information Services—Data Sharing and Web-based Services; H.2.1 [Database Management] Systems.

By integrating the many different technologies and approaches involved in electronic education and commerce, we can effectively support advanced applications in these areas. This paper describes an architecture which can be used to facilitate the specification, execution, and distribution of incremental trade documents among heterogeneous interchanges. We argue that the conventional, top-down, centralized approach to workflow, in its current state, is not suitable to support the undetermined nature of an advanced trade application. What this approach lacks is a unified object-oriented model which can be used to design interoperable trading systems with a single set of well-defined abstractions. This paper, in an attempt to overcome the limitations imposed by the conventional approach, presents an overview of principles relating to object interoperability, semantic heterogeneity, and the document-centric paradigm associated with trade documents. A view object model and its relevant components are also discussed.

The difficult problems in the design of systems which facilitate interoperation and mediation among information sources and their consumers arise from the presence of semantic heterogeneity among the schemas and ontologies supporting the different services. The purpose of this paper is to develop a taxonomy of semantic heterogeneity, and to describe, taking the perspective of text databases, the conditions under which autonomy-respecting interoperation of different kinds are likely to be feasible. The main conclusion is that interoperation can be based on structured database technology only if the participating organizations communicate among themselves, otherwise the considerations underlying text databases dominate the technology used.

The core of this article is a proof that stratified Horn clause propositional systems are equivalent to and can be efficiently transformed into decision tables by a process closely related to assumption-based truth maintenance. the transformed systems execute much faster and in a bounded time, leading to the possibility of executing real-time expert systems in microseconds on fine-grained parallel computers. One consequence is to simplify the consistency and completeness analysis for such systems, in particular the problem of ambiguity. A deeper consequence is that it makes sense to view these systems as stochastic processes. This, and an analysis of the problem of maintenance of these systems, leads to the conclusion that by and large rule induction approaches are better than rule construction approaches for building them. © 1995 John Wiley & Sons, Inc.

Knowledge bases contain specific and general knowledge. In relational database systems, specific knowledge is often represented as a set of relations. The conventional methodologies for centralized database design can be applied to develop a normalized, redundancy-free global schema. Distributed database design involves redundancy removal as well as the distribution design which allows replicated data segments. Thus, distribution design can be viewed as a process on a normalized global schema which produces a collection of fragments of relations from a global database. Clearly, not every fragment of data can be permitted as a relation. In this paper, we clarify and formally discuss three kinds of fragmentations of relational databases, and characterize their features as valid designs, and we introduce a hybrid knowledge fragmentation as the general case. For completeness of presentation, we first show an algorithm for the validity test of vertical fragmentations of normalized relations, and then extend it to the more general case of unbiased fragmentations.

Abstract As Prolog becomes more widely used, it becomes important to provide clear and consistent implementations of the assert and retract primitives. This paper introduces a bit‐map indexing system with a consistent semantics. It also considers the implementation of the interface between Prolog and an external source of clauses, concentrating on the storage of clauses on secondary storage, but considering also the presentation of data to Prolog programs by non‐Prolog processes.