David W. Jensen

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As parallel systems expand in size and complexity, the absence of performance tools for these parallel systems exacerbates the already diicult problems of application program and system software performance tuning. Moreover, given the pace of technological change, we can no longer aaord to develop ad hoc, one-of-a-kind performance instrumentation software;(More)
The National Center for Supercomputing Applications (NCSA) at the University of Illinois typifies current, high-performance computing centers that support a diverse user base of both academic and industrial accounts. The data requirements of this user community, coupled with resource constraints, mandate the use of an archival file system. This paper(More)
To minimize energy consumption by voltage scaling in design of heterogeneous real-time embedded systems, it is necessary to perform two distinct tasks: task scheduling (TS) and voltage selection (VS). Techniques proposed to date either are fast but yield inefficient results, or output efficient solutions after many slow iterations. As a core problem to(More)
Head and eye movements in the yaw plane were recorded during and after optokinetic stimulation in squirrel monkeys. 1) Phasic or tonic head deviations to the side of the ocular quick phase occurred in 94% of total recordings (n = 50) during the perstimulus period, and in 75% of recordings (n = 49) during the poststimulus period. Magnitude of mean head(More)
We use linear mixed models to predict winter steelhead (Oncorhynchus mykiss) redd density from geology, land use, and climate variables in the Willamette River basin, Oregon. Landscape variables included in the set of best models were alluvium, hillslope < 6%, landslide-derived geology, young (<40 years) forest, shrub vegetation, agricultural land use, and(More)
Cerebellar lesion experiments have led to the concept that the medial longitudinal zone controls postural tone while the intermediate zone controls discrete movement. This study is a test of the hypothesis that, of the two zones, the medial zone is more closely linked to the resting discharge of vestibular afferent fibers, a prime source of neural tonus(More)