The Protg project has come a long way since Mark Musen first built the Protg metatool for knowledge-based systems in 1987. The original tool was a small application, aimed at building knowledge-acquisition tools for a few specialized programs in medical planning. From this initial tool, the Protg system has evolved into a durable, extensible platform for knowledge-based systems development and research. The current version, Protg-2000, can be run on a variety of platforms, supports customized user-interface extensions, incorporates the Open Knowledge Base Connectivity (OKBC) knowledge model, interacts with standard storage formats such as relational databases, XML, and RDF, and has been used by hundreds of individuals and research groups. In this paper, we follow the evolution of the Protg project through 3 distinct re-implementations. We describe our overall methodology, our design decisions, and the lessons we have learned over the duration of the project.. We believe that our success is one of infrastructure: Protg is a flexible, well-supported, and robust development environment. Using Protg, developers and domain experts can easily build effective knowledge-based systems, and researchers can explore ideas in a variety of knowledge-based domains.

. A competency description of a software component seeks to describe what the artefact can and cannot do. We focus on a particular kind of competence, called fitness-for-purpose, which specifies whether running a software component with a supplied set of inputs can satisfy a given goal. In particular, we wish to assess whether a chosen problem solver, together with one or more knowledge bases, can satisfy a given (problem solving) goal. In general, this is an intractable problem. We have therefore introduced an effective, practical, approximation to fitness-for-purpose based on the plausibility of the goal. We believe that constraint (logic) programming provides a natural approach to the implementation of such approximations. We took the Common LISP constraints library SCREAMER and extended its symbolic capabilities to suit our purposes. Additionally, we formulated an example of fitness-for-purpose modelling using this enhanced library. 1 Introduction A competency descrip...

By applying recent advances in the standards for distributed computing, we have developed an architecture for a CORBA implementation of a library of platform-independent, sharable problem-solving methods and knowledge bases. The aim of this library is to allow developers to reuse these components across different tasks and domains. Reuse should be cost effective; therefore, the library will include standard problem-solving methods whose semantics are well understood and are described with a language for stating the requirements and capabilities of a component. In addition, when a developer needs to adapt a component to a new task, the adaptation costs should be minimal. Thus, we advocate the use of separate mediating components that isolate these adaptations from the original component. We demonstrate our approach with an example: an implementation of a problem-solving method, a knowledge-base server, and mediating components that adapt the method to different knowledge bases and tasks.

Needs-driven service bundling in a multi-supplier setting The computational e 3 service approach Sybren de KinderenVRIJE UNIVERSITEIT Needs-driven service bundling in a multi-supplier setting The computational e 3 service approach ACADEMISCH PROEFSCHRIFT ter verkrijging van de graad Doctor aan de Vrije Universiteit Amsterdam, op gezag van de rector magnificus prof.dr. L.M. Bouter, in het openbaar te verdedigen ten overstaan van de promotiecommissie van de faculteit der Exacte Wetenschappen op maandag 25 oktober 2010 om 13.45 uur in de aula van de universiteit,

The discipline of knowledge engineering grew out of the early work on expert systems in the seventies. With the growing popularity of knowledge-based systems (as these were by then called), there arose also a need for a systematic approach for building such systems, similar to methodologies in main-stream software engineering. Over the years, the