We present a theory of object-orientation on the basis of the re-nement calculus. This theory allows for specifying the behaviour of objects and provides a calculus for the proof of relationships between classes such as reenement. Given two similar, but not identical classes, we present an algorithm to construct a common superclass which is reened by both classes, and an algorithm to construct ...

This paper describes how object-oriented software construction principles allow to develop extensible and reusable building blocks for the development of data flow based visual languages. First we’ll present the data flow visual language ProtoHyperflow whose object-oriented realization is discussed in the second part of the paper.

The partial phase behavior of systems composed of lecithin/isopropyl myristate (IPM)/water or ketorolac tromethamine (KT) solutions (2.5, 5, 10 and 50% w/w) at various lecithin/IPM weight ratios (km) have been investigated by the construction of phase diagrams. A commercially available soybean lecithin (namely, Epikuron 200, phosphatidylcholine purity greater than 95%) was used in this study. P...

In this paper we develop two coadjoint orbit constructions for the phase spaces of the generalised Sl(2) and Sl(3) KdV hierachies. This involves the construction of two group actions in terms of Yang Baxter operators, and an Hamiltonian reduction of the coadjoint orbits. The Poisson brackets are reproduced by the Kirillov construction. From this construction we obtain a ‘natural’ gauge fixing p...

This paper presents a set of tools supporting the construction of nearly every compiler phase. Design goals of this tool box have been practical usability, significantly reduced effort for compiler construction, and high quality of the generated compilers. Especially efficiency should be competitive to hand crafting. Currently modules in the target languages C and Modula-2 can be generated. Fir...

Traditionally, database management systems use tree-structured query evaluation plans. They are easy to implement but not expressive enough for some optimizations like eliminating common algebraic subexpressions or magic sets. These require directed acyclic graphs (DAGs), i.e. shared subplans. Existing approaches consider DAGs merely for special cases and not in full generality. We introduce a ...

Acknowledgement Thanks are owed to a number of people, without whose help this project would not have been possible. First, to the members of my examining committee: Dr. Randy R. suggestions, and general support were instrumental in helping to focus and define the scope of the project. Particular thanks go to my committee chair, Dr. Rapp, a faithful reviewer and provider of direction. By any me...

The Beijing Electron-Positron Collider (BEPC) was constructed for both high energy physics and synchrotron radiation researches. As an e, e collider operating in the τ-charm region and the first synchrotron radiation source in China, the machine has been well operated more than 15 years since it was put into operation. As a collider, the peak luminosity of the BEPC has reached its design goal o...

The use of the Maxwell construction, in conjunction with the van der Waals equation of state, to represent the liquefaction of gases is familiar to all students of thermodynamics. The present paper is concerned with the application of the Maxwell construction to Fermi fluids, and in particular with the question as to whether or not they can undergo a liquid-gas phase transition at T= 0. We shal...