James B. Armstrong

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A tutorial overview of how selected computer-vision-related algorithms can be mapped onto reconfigurable parallel-processing systems is presented. The reconfigurable parallel-processing system assumed for the discussions is a multiprocessor system capable of mixed-mode parallelism; that is, it can operate in either the SIMD or MIMD modes of parallelism and(More)
A method to migrate a task dynamically from a virtual SPMD machine to a virtual SIMD machine is proposed. It is assumed that the SIMD and SPMD virtual machine models only differ to support the different modes of parallelism, and that the program was coded in a mode-independent programming language. The migration pro­ cedure does not require the SPMD PEs to(More)
Beginning at mid-neurulation, a wave of somite segmentation passes down the axolotl body axis in a cephalocaudal direction. At 20 degrees C a somite forms every 2.57 hr. Fate-mapping of the presomitic mesoderm indicates that the primordia for the next few somites occupy nearly the same space that they will after segmentation, but that the remaining somites(More)
The mechanosensory lateral-line system offers a unique opportunity to study a wide variety of developmental phenomena, including cell migration, the origin of polarity, and pattern formation. In this study, we use a series of transplantation experiments to examine some of the factors affecting the origin of the lateral-line placodes, the establishment of(More)
Performance of a parallel algorithm on a parallel machine depends not only on the time complexity of the algorithm, but also on how the underlying machine supports the fundamental operations used by the algorithm. This study analyzes various mappings of image correlation algorithms in SIMD, MIMD, and mixed-mode environments. Experiments were conducted on(More)
Performance of a parallel algorithm on a parallel machine depends not only on the time complexityof the algorithm, but also on how the underlying machine supports the fundamental operations used by the algorithm. This study analyzes various mappings of image correlation algorithms in SIMD, MIMD, and mixed-mode environments. Experiments were conducted on the(More)
A mixed-mode parallel machine's processing elements are capable of operating in and switching between the SIMD and MIMD modes of parallelism. This paper analyzes various mappings of image correlation algorithms onto a mixed-mode parallel processing system. The trade-offs that exist between the SIMD and MIMD modes are the primary basis employed in comparing(More)