Herbert Stoyan

Programming Styles in Artificial Intelligence

In this paper we discuss a class of methods which have been used in some of the most influential work in AI: The invention of new execution models (abstract computers), their implementation and their usage for exploring new ways of programming.

EPK-fix: Methods and Tools for Engineering Electronic Product Catalogues

An electronic product catalogue (EPC) is a computer controlled information system with multimedia product presentations and navigation facilities. The paper presents the results of the EPK-fix project for the systematic construction of EPCs. These include a software engineering process model, a high level specification language for EPCs, and an integrated set of tools supporting the entire EPC development process. The EPK-fix process model supports the classical development phases: requirements analysis, specification and design, implementation, and test. In each of the phases emphasis is put on the particular multimedia aspects, human machine interaction, production of prototypes, and the quality of the produced documents.

The WebConsultant - a Flexible Framework for Dynamic Web Applications

Web-based consultancy and e-commerce are important services in the rapidly growing internet market. The engineering of Web-based consultancy applications is like the engineering of Web applications in general not yet supported by a methodical approach and adequate process models. This article presents a process model for Web software engineering and an appropriate execution model for Web consultancy. The models have been used in the specification and prototypic implementation of the WebConsultant, a tool that collects customer data in a client-server architecture in order to decide on the subsequent course of the interview. The XML-application ISDL is used to define the structure and flow of interviews. The content of an ISDL-document determines the course of an interview dependent on the customers input. As a result, consultancy Web pages that display relevant extracts of a database are produced.

Lisp 50 years ago

I acknowledge the help of David Elsweiler to get this paper more readable.

A Hybrid Approach to Product Information Extraction on the Web

In this paper we present a hybrid approach to product information extraction on the web that combines the main advantages of different web-scale algorithms. Like redundancy-based systems, it utilizes the redundancy of the web and uses a search engine to autonomously search for relevant web pages. Additionally it extracts whole product specifications instead of simple facts or binary relations. Like structure-based systems, it employs heuristic assumptions about the general structure of lists and tables, but similarly to ontology-based systems uses domain-specific knowledge to guide the search and the extraction. The difference to those is that our ontology is a feature template that is much simpler to generate and maintain. Also, experimental results are provided to demonstrate the effectivity of our approach.

Evolution of Agent Coordination in an Asynchronous Version of the Predator-Prey Pursuit Game

In this paper, we introduce an asynchronous version of the well-known pursuit game. The validity of past results on the synchronous version of the pursuit game is verified in this new setting by considering five kinds of prey: Still prey, randomly moving prey, avoiding prey, linear prey, and linear prey with switching behavior. Genetic programming is used to evolve teams of predators whose capture rates are compared to that of a greedy strategy. Task assignment is used as an explicit means of coordination in the evolved teams of predators. We conclude that evolved teams with explicit coordination outperform greedy non-cooperative strategies when more competent prey is faced.

Nachrichtenverarbeitung -Objekt-orientierte Programmierung (1)

Fur den Menschen erscheint - zumindest was die wissenschaftliche Welterkenntnis betrifft - eine Gliederung der Welt in Objekte, die sich mit der Zeit andern konnen, naturlich1. Dieser bisher einigermasen erfolgreichen Weltsicht ist noch keine andere gleich leistungsfahige gegenuberstellt worden, obwohl die Probleme der geschilderten Sicht unubersehbar sind.

LISP compilation viewed as provable semantics preserving program transformation

This paper is based on the view that the main stage of compilation, the code generation phase, has very much in common with the simplification of algebraic expressions. The compiler is seen as symbolic program manipulator, the so-called intermediary language as data-structure (a combination of tree structures and symbol table) to store programs which is convenient for executing simplification, decomposition and optimization steps. The main aspect of code generation is decomposition leading to a program which is still using constructs of the source language but without any composed parts. It is based on a few operations on the internal data-structure-representation of the source program.

Laufend weiter konzipieren

Neuere Konzepte der Informatik sollten in die Modelle der Erforschung von Textproduktionsprozessen integriert werden. In diesem Beitrag wird gezeigt, wie Dokumente reprasentiert sein mussen, damit sie samtliche Informationen behalten, die beim Schreiben eingeflossen sind. Das erweitert nicht nur im konkreten Fall die Moglichkeiten von Textkonzeption und -reproduktion, sondern ist Teil eines Informationsmanagements, das die Wissenschaftlerinnen bei ihrer Arbeit langfristig unterstutzt. Ausgehend von der wissenschaftlichen Textproduktion (1) werden existierende Forschungsansatze zur optimierten Textproduktion am Computer diskutiert (2). Basierend auf den Anforderungen an das Arbeitsmedium wird ein integratives Rahmenmodell entwickelt (3). Anhand der Rolle von Strukturen bei der Produktion von Texten wird dieses konkretisiert und ein darauf aufbauendes Werkzeug kurz illustriert (4). Eine Diskussion und ein Ausblick schliesen den Beitrag ab (5).

An agent-based approach to correctness in databases

When defining the schema of a relational database, integrity constraints are included to describe simple syntactic constraints of correctness that can easily be tested in a centralized way when tuples are inserted, deleted or updated. Complex dependencies may exist between different tuples of a relation. The description of them can be difficult with current formalisms. An example for such an inconsistency is the problem of duplicates, the existence of different tuples describing the same real world entity. Duplicates can occur when one makes typographic or other errors while transferring the representation of a real-world entity to the database. In this paper, we describe a new method to detect dependencies of that kind using continuously active agents that check consistency of a database and propose steps to improve the content of the database.