This paper constitutes a further step in the analysis of distributed-memory MIMD parallel machines used in dataparallel applications. In particular, this analysis considers the problem of managing the software-level interactions among various processing nodes whenever the program cannot be classified as fully data parallel because it requires some processing of data belonging to different parti...

The key concept of autoepistemic logic introduced by Moore is a stable expansion of a set of premises, i.e., a set of beliefs adopted by an agent with perfect introspection capabilities on the basis of the premises. Moore's formal-ization of a stable expansion, however, is non-constructive and produces sets of beliefs which are quite weakly grounded in the premises. A new more constructive defi...

A class of nonhomogeneous Markov systems with hierarchic state space working in diierent scales of time (slow and fast) that are adequate mathematical models at the analysis and modelling of various classes of computing systems and networks of a complex stochastic structure is studied. Models of asymptotic decreasing dimension and enlargement (merging) of state space are considered. Application...

A quasi-structure factor method is used to show how sharp diffraction patterns are produced by aperiodic quasicrystals. Icosahedral symmetry is described for the tensor rank 3 solids with edgesharing unit cells that are pentagonally close packed in hierarchic structures having a geometric reciprocal lattice. The hierarchic symmetry replaces translational symmetry in crystal diffraction. Details...

Hierarchic document clustering has been widely applied to Information Retrieval (IR) on the grounds of its potential improved effectiveness over inverted file search. However, previous research has been inconclusive as to whether clustering does bring improvements. In this paper we take the view that if hierarchic clustering is applied to search results (query-specific clustering), then it has ...

We present a method to identify all compact, contiguous-chain, structural units in a globular protein from x-ray coordinates. These units are then used to describe a complete set of hierarchic folding pathways for the molecule. Our analysis shows that the larger units are combinations of smaller units, giving rise to a structural hierarchy ranging from the whole protein monomer through supersec...