Masters Theses

Date of Award

8-1993

Degree Type

Thesis

Degree Name

Master of Science

Major

Computer Science

Major Professor

Michael W. Berry

Committee Members

Jack Dongarra, Bob Gardner

Abstract

In landscape ecology, computer modeling is used to assess habitat fragmentation and its ecological implications. Specifically, maps (2-D grids) of habitat clusters are analyzed to determine numbers, sizes, and geometry of clusters. Previous ecological models have relied upon sequential Fortran-77 programs which have limited the size and density of maps that can be analyzed. To efficiently analyze relatively large maps, we present parallel map analysis software implemented on the CM-5. For algorithm development, random maps of different sizes and densities were generated and analyzed. Initially, the Fortran-77 program was rewritten in C, and the sequential cluster identification algorithm was improved and implemented as a recursive or nonrecursive algorithm. The major focus of parallelization was on cluster geometry using C with CMMD message passing routines. Several different parallel models were implemented: host/node, hostless, and host/node with vector units (VUs). All models obtained some speed improvements when compared against several RISC-based workstations. The host/node model with VUs proved to be the most efficient and flexible with speed improvements for a 512 x 512 map of 187, 95, and 20 over the Sun Sparc 2, HP 9000-750, and IBM RS/6000-350, respectively. When tested on an actual map produced through remote imagery and used in ecological studies this same model obtained a speed improvement of 119 over the Sun Sparc 2.

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