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Issue No.01 - January (1990 vol.39)

pp: 99-110

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/12.46284

ABSTRACT

<p>A distributed computing system and cooperating tasks can be represented by a processor graph G/sub p/=(V/sub p/, E/sub p/) and a task graph G/sub T/=(V/sub T/, E/sub T/), respectively. An edge between a pair of nodes in G/sub T/ represents the existence of direct communications between the two corresponding tasks. The maximal number of hops between two processors in G/sub p/ to which two adjacent tasks in G/sub T/ are assigned is called dilation of that assignment. Characterization and use of the number of acceptable assignments for given G/sub T/ and G/sub P/ are treated. Assignments with the dilation less than or equal to one are considered. This dilation constraint represents a special case in which two adjacent tasks in G/sub T/ must be assigned to either a single processor or two adjacent processors in G/sub p/. For the case where N(G/sub T/, G/sub P/) denotes the numbers of acceptable assignments under this constraint, N(G/sub T/, G/sub P/) are derived for arbitrary G/sub T/ and G/sub P/, and a recursive expression is formulated for N(G/sub T/, G/sub P/) when G/sub T/ is a tree. For some restricted cases, either closed-form or recursive-form expressions of N(G/sub T/, G/sub P/) are derived. The results on N(G/sub T/, G/sub P/) are extended to the completely general case, assignments with dilations greater than one, where two adjacent tasks in G/sub T/ can be assigned to any two processors in G/sub P/ which are not necessarily adjacent to each other.</p>

INDEX TERMS

acceptable task assignments; distributed computing systems; cooperating tasks; processor graph; hops; dilation; distributed processing; graph theory.

CITATION

K.G. Shin, "On the Number of Acceptable Task Assignments in Distributed Computing Systems",

*IEEE Transactions on Computers*, vol.39, no. 1, pp. 99-110, January 1990, doi:10.1109/12.46284