Subsumption between queries to object-oriented databases

Most work on query optimization in relational and object-oriented databases has concentrated on tuning algebraic expressions and the physical access to the database contents. The attention to semantic query optimization, however, has been restricted due to its inherent complexity. We take a second look at semantic query optimization in object-oriented databases and find that reasoning techniques for concept languages developed in Artificial Intelligence apply to this problem because concept languages have been tailored for efficiency and their semantics is compatible with class and query definitions in object-oriented databases. We propose a query optimizer that recognizes subset relationships between a query and a view (a simpler query whose answer is stored) in polynomial time

Verbmobil : translation of face-to-face dialogs

Verbmobil is a long-term project on the translation of spontaneous language in negotiation dialogs. We describe the goals of the project, the chosen discourse domains and the initial project schedule. We discuss some of the distinguishing features of Verbmobil and introduce the notion of translation on demand and variable depth of processing in speech translation. Finally, the role of anytime modules for efficient dialog translation in close to real time is described

Theoretical consideration of goal recognition aspects for understanding information in business letters

Businesses are drowning in information - paper forms, e-mail, phone-calls and other media do struggle the speed of managers in handling and processing information. Traditional computer systems do not support business flow because of their inflexibility and their lack in understanding information. A sophisticated understanding of the meaning of a business letter requires an understanding of why the sender wrote it. This paper describes some ideas to use goal recognition techniques as one possibility, or method to initiate information understanding. It brings together two areas of cognition: goal recognition and document understanding. To do so, it gives an overview of the application of goal recognition techniques to the discovery of the overall purpose of a letter and a coherent explanation of how the individual sentences are meant to achieve that purpose

Corporate agents

The logic of belief and intention in situations with multiple agents is increasingly well understood, but current formal approaches appear to face problems in applications where the number of agents greatly exceeds two. We provide an informal development of Corporate Agents, an intensional approximation of individual and group states which treats groups symmetrically with autonomous agents. Corporate Charters, constraints derived from typical patterns of information flow, replace detailed reasoning about the propagation of attitudes in most contexts. The approximation to an ideal logical formulation is not tight, but the model appears to function well in information-poor environments and fails in ways related to characteristic human errors. It may therefore be particularly appropriate to application in the area of natural language discourse

Using integrated knowledge acquisition to prepare sophisticated expert plans for their re-use in novel situations

Plans which were constructed by human experts and have been repeatedly executed to the complete satisfaction of some customer in a complex real world domain contain very valuable planning knowledge. In order to make this compiled knowledge re-usable for novel situations, a specific integrated knowledge acquisition method has been developed: First, a domain theory is established from documentation materials or texts, which is then used as the foundation for explaining how the plan achieves the planning goal. Secondly, hierarchically structured problem class definitions are obtained from the practitioners\u27 highlevel problem conceptualizations. The descriptions of these problem classes also provide operationality criteria for the various levels in the hierarchy. A skeletal plan is then constructed for each problem class with an explanation-based learning procedure. These skeletal plans consist of a sequence of general plan elements, so that each plan element can be independently refined. The skeletal plan thus accounts for the interactions between the various concrete operations of the plan at a general level. The complexity of the planning problem is thereby factored in a domain-specific way and the compiled knowledge of sophisticated expert plans can be re-used in novel situations

Konzeption einer deklarativen Wissensbasis über recyclingrelevante Materialien

Das Recycling von Produkten und Produktionsreststoffen erlangt als Einflußfaktor für wirtschaftliche Entscheidungsprozesse eine immer größere Bedeutung. Die Integration von recyclingrelevanten Daten in betriebliche Informationsstrukturen sollte in Zukunft durch wissensbasierte Methoden unterstützt werden. Wir stellen Ansätze für eine Wissensbasis zur recyclinggerechten Produkt- und Produktionsplanung vor, und gehen dann genauer auf das grundlegende Modul über Materialien ein. Es wird untersucht, welche Evolutionstechniken sich zur Pflege derartiger Wissensbestände eignen, z.B. zur Validierung vorhandener und Exploration neuer Materialien im Hinblick auf ihre Recycelbarkeit

The refitting of plans by a human expert

During the course of the development of a Case-Oriented Expert System for situated applications additional cases were needed. The required cases were obtained by having a human expert refit old solutions to new problems and the structural relations between source and target cases were analyzed: A higher degree of reuse of the old cases was found when the expert could apply derivational reasoning and a uniform design rationale (i.e. the solution of the source was generated by the expert himself) than when the expert could only analyze structural relationships (i.e. the source solution was constructed by some one else). Except with very obvious cases, it was also found, that different experts perceive different cases as the most similar source to a given target problem. The results also indicate for user-situated applications of expert systems

Hierarchical skeletal plan refinement : task- and inference structures

This paper presents the task- and inference structure for skeletal plan refinement which was developed for lathe production planning, the application domain of the ARC-TEC project. Two inference structures are discussed: a global inference structure which was developed in the first phase of knowledge acquisition and a more detailed inference structure which builds on the hierarchical organization of the skeletal plans. The described models are evaluated with respect to their cognitive adequacy and their scope of application. The benefits and limitations of the KADS knowledge acquisition methodology are discussed with respect to the development of the two models

Akquisition und Repräsentation von technischem Wissen für Planungsaufgaben im Bereich der Fertigungstechnik

Im Bereich der Fertigungstechnik kann eine Fülle von Planungsaufgaben identifiziert werden, die für eine Bearbeitung mit Methoden der KI geeignet erscheinen. Das Projekt ARC-TEC am DFKI wendet die KADS-Methode zur systematischen Entwicklung von Expertensystemen an und erstellt Tools für alle Phasen dieser Entwicklung. Die Brauchbarkeit der entwickelten Methoden und Tools wird am Beispiel der Erstellung von Arbeitsplänen für die Drehbearbeitung demonstriert. Besonderes Augenmerk gilt dabei der expliziten Repräsentation des konkreten Expertenwissens und der Bearbeitung des gegebenen Problems in einer der Vorgehensweise des Experten möglichst naheliegenden Weise.In the area of production engineering many planning tasks can be found which seem well-suited to be tackled using AI-methodologies. The ARC-TEC project of the DFKI uses the model based KADS approach for a systematic development of expert systems and provides tools to support the different phases of this development. The generation of work plans for manufacturing by turning is used as an example to demonstrate the applicability of the different tools and methodologies. Special focus is upon the explicit representation of the concrete experts knowledge and the problem solving strategy which closely follows the way an expert solves the problem