A model for disk accesses based on published measurements is developed. The model is used to show that under highly probable conditions, FCFS seek scheduling is superior to SSTF scheduling in the sense of having a lower mean queue length. A simple example of an arrival sequence illustrating this anomaly is presented.
The performance of a disk system is often measured in terms of the length of the waiting line or queue of requests for each of the system's spindles. Thus it is natural to formulate and analyze queueing models of disk systems. While most disk systems have certain characteristics, such as channel interference and concurrent seeks, in common, previous… (More)
It is unclear whether malocclusion characterized by jaw discrepancy is caused by variations in mandibular position, mandibular size, or a combination of the two. To clarify the situation, the mandibular outlines of 124 10-year-old boys, equally divided among the Angle classes, were generated from cephalograms with a computer plotting technique. The mean… (More)