The contraction model of Field and Colgate for proto-galaxies, first proposed to describe the observed properties of quasars, is generalized and used to investigate the evolution of galaxies. The LEDA data base for elliptical, spiral, compact and diffuse galaxies is employed and it is shown that the above model is consistent with observational evidences regarding their dynamical evolution, star...

In this paper we present an environment for the development of special purpose heterogeneous analysis and veriication tools, which is unique in 1) constituting a framework for the development of application speciic heterogeneous tools and 2) providing facilities for the automation of the synthesis process. Based on a speciication language that uniformly combines taxonomic component speciication...

1. INTRODUCTION Keyword search, which is extensively used for searches over flat HTML documents on the web, is a simple and effective paradigm for information discovery. have studied how to effectively apply this useful paradigm to searches over XML documents. XML Keyword search makes it possible for users to obtain relevant information without having to know complex query syntaxes (

Jag beskriver här i korthet datoröversättningssystemet Distributed Language Translation (DLT) och tar i samband med detta upp Nordens språk. DLT är ett omfattande forskningsoch utvecklingsprojekt som bedrivs av det nederländska softwareföretaget Buro voor Systeemontwikkeling (BSO/Research i Utrecht) med anslag från Nederländernas Ekonomidepanement. Projektet är inne på en än så länge icke-komme...

In this paper, we propose an XML data placement scheme by optimally partitioning XML data among multiple broadcast channels in such a way that it minimizes the average response time of mobile clients in processing of different XML queries. By performing several experiments, we have shown that our proposed XML data placement scheme improves the performance of XML query processing of mobile clien...

We consider the problem of fairly dividing a two dimensional heterogeneous good among multiple players. Applications include division of land as well as ad space in print and electronic media. Classical cake cutting protocols primarily consider a one-dimensional resource, or allocate each player multiple infinitesimally small “pieces”. In practice, however, the two dimensional shape of the allo...

A program checker verifies that a particular program execution is correct. We give simple and efficient program checkers for some basic geometric tasks. We report about our experiences with program checking in the context of the LEDA system. We discuss program checking for data structures that have to rely on user-provided functions.

Using well-defined selection criteria applied to the LEDA galaxy catalogue we have constructed a sample of elliptical galaxies that can be taken to lie in the field. Such criteria can easily be applied to theoretical simulations for direct comparison with observations. The variation of the number of ‘isolated’ ellipticals with selection criteria is also investigated. A preliminary study of the ...

XML data can be represented by a tree or graph structure and XML query processing requires the information of structural relationships among nodes. The basic structural relationships are parent-child and ancestor-descendant, and finding all occurrences of these basic structural relationships in an XML data is clearly a core operation in XML query processing. Several node labeling schemes have b...