Suchergebnisse

The current dramatic evolution in information technology is bringing major modifications in the way scientists work and communicate. The concept of electronic information handling -and thus of electronic publishing -encompasses the diverse types of information, the different media, as well as the various communication methodologies and technologies. The structure itself of information has become different by the introduction ofhypertextual links. Fluid information is becoming a common concept. While publication is considered here as a public announcement (no implicit assumption being made as to the medium used), it is obvious that electronic publishing will have to diverge from an electronic version of contributions on paper and will become part of a more general diversified publishing policy. The procedures for validating published material and for evaluating scientific activities will have to be adjusted too. Provision of electronic refereed informa¬ tion independently from commercial publishers is now feasible and even maybe highly recommended in view of strict copyright policies tentatively applied by some publishers to the electronic material. In other terms, scientists and scientific institutions have now the possibility to run an efficient information server with validated (refereed) material without the help of a commercial publisher.

A comparative study is made between the following methods : Newton-Raphson method, Davidon-Fletcher-Powell method and modified Gauss-Newton method. These were applied to the maximization of a likelihood function of very general use in astronomy. Our analysis shows that the most satisfactory method is the last quoted.