Jo Ann Lockett

Dynamic Programming and Ill-Conditioned Linear Systems-II.

Abstract : The aim of this memorandum was to show how an illconditioned linear system Ax = y, can be solved. Realizing that there exists a certain degree of smoothness in the solution, and attempt was made to determine x by minimizing, for appropriate values of lambda, the form (ax-y, ax-y) + lambda D sub N (x). This was done in a sequential fashion, using dynamic programming, so that no matrix inversions were required.

Computer performance analysis in mixed on-line/batch workloads

Analysts may measure and analyze a mixed-workload system for a variety of reasons. As a first example, it may be necessary to cut costs by reducing equipment. Before arbitrarily removing some piece of equipment, management should determine how the on-line and batch systems will be affected. If problem areas can be identified prior to equipment removal, action can be taken to reduce any negative impact. The next decision may then involve the selection of equipment to remove. This decision could best be made if comparative data on the performance of the various configurations were obtainable.

A simple technique for controlled on-line system stimulation

Most performance analysis tools are developed with the objective of providing data in a general way, using flexible techniques, with confidence that analysts will subsequently employ them in cost/effective procedures. The inadequacy of this approach is reflected by the frequency of questions about which data to collect and how to use them. The problem is the initial emphasis on tools as an end in themselves rather than on analysis techniques.