In this paper we present a new parallel clustering algorithm based on the extended star clustering method. This algorithm can be used for example to cluster massive data sets of documents on distributed memory multiprocessors. The algorithm exploits the inherent data-parallelism in the extended star clustering algorithm. We implemented our algorithm on a cluster of personal computers connected ...

ABSTRACT We present a revised and extended version of the analytical model for cosmic star formation originally given by Hernquist Springel in 2003. The key assumption this formalism is that proceeds from cold gas, at rate limited an internal consumption time-scale early times, or generation gas via cooling late times. These processes are analysed as function mass dark matter haloes integrated ...

We summarize results of our HST imaging survey of protoplanetary nebula (PPN) candidates, in which we discovered two types of axisymmetric reflection nebulosities. The Star-Obvious Low-level-Elongated (SOLE) nebulae show a bright central star embedded in a smooth, faint extended nebulosity, whereas the DUst-Prominent Longitudinally-EXtended (DUPLEX) nebulae have remarkable bipolar structure wit...

star identification is one of the most important stages in attitude determination with star trackers. this can be performed using matching algorithms between observed stars and a master star catalogue. the main challenge in this approach is to provide a fast and reliable identification algorithm that is sufficiently robust in different pointing views of the star tracker optical system in the sp...