This paper describes a knowledge representation and reasoning system that performs a limited but interesting class of inferences over a restricted class of first-order sentences with optimal eticiency. The proposed system can answer yes-no as well as w/z-queries in time that is only proportional to the Zength of the shortest derivation of the query and is independent of the size of the knowledg...

Increasingly, knowledge is recognized as a critical asset, where a firm or an individual’s competitive advantage flows from a unique knowledge base. The subsequent degree to which knowledge is then recognized and valued as a resource, has been the theme of many papers on competitive advantage (Prahalad and Hamel, 1990; Barney, 1991; D’Aveni, 1994; Teece and Pisano, 1994; Spender, 1996; Nonaka a...

The usage of computer applications in the construction industry has steadily increased over the years, as has the complexity of many applications. However, project managers, who are usually responsible for making decisions, are not necessarily familiar with these ever-increasingly complex applications. As a result, a question answering system is needed for efficiently managing construction proj...

Research currently in progress at the University of Bielefeld is concerned with conceptualizing a methodological framework which allows large-scale knowledge bases to be constructed, utilized and maintained in a modular fashion. Challenges to be met span from the modular conception of domain knowledge in a given application area on the one hand to the adaption of principles for modular system d...

My research so far has been focused on integrating and developing methodologies, techniques, tools and resources to support a precise manual knowledge representation, sharing and retrieval (KRSS). The resulting models, notations and normalization techniques for representing, indexing, querying, evaluating and integrating knowledge are however also important to follow for precision-oriented (sem...

In Rough Set Theory, dependency in the knowledge base is an important aspect when drawing inferences about the world. Rough set (inexact set) is defined by using a fixed binary relation (equivalence relation, tolerance relation, similarity relation, etc) to analyze vague, imprecise, inexact problems, which satisfy many interesting properties. The neighborhood based rough set theory is an extens...

A most crucial problem in knowledge representation is the revision of knowledge when new, possibly contradictory, information is obtained (belief revision). In this report, we address this problem when the knowledge base is a set of expressions in propositional logic. We introduce a new representation of propositional expressions using 2-dimensional matrices and provide the theoretical underpin...

In this paper, we present an original knowledge representation approach dedicated to ITS. It combines a strict ontological representation for authoring purposes and an ontology-based knowledge base used in domainindependent problem-solving. This approach benefits from recent developments in ontology engineering to propose an alternative to established formalisms. We explain the advantages of us...

Lexical, ontological, as well as encyclopedic knowledge is increasingly being encoded in machine-readable form. This paper deals with knowledge representation in multilingual settings. It begins by proposing a generic graph-based knowledge base framework, and then, in three case studies, explains how preexisting knowledge can be cast into this framework. The first case study involves enriching ...

In this paper I examine the utilisation of knowledge representation in Computer-Aided Learning (CAL) with the aim of establishing knowledge-based CAL techniques that are best suited to current technology. Most existing knowledge-based CAL systems attempt to generate the entire instructional sequence directly from a domain knowledge base. Such systems suffer from several limitations. These limit...