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A method for scheduling final examinations to yield a minimal number of student conflicts is described. The “minimization” is achieved by repetitively evaluating a nonlinear set of equations. Imbedded in the process is a random or Monte Carlo selection of assignments. As in such heuristic techniques, the solution may not be optimum and many solutions may be found which yield locally minimal results. Computer programs are described and empirical results given.
A simple automatic derivative evaluation program
A procedure for automatic evaluation of total/partial derivatives of arbitrary algebraic functions is presented. The technique permits computation of numerical values of derivatives without developing analytical expressions for the derivatives. The key to the method is the decomposition of the given function, by introduction of intermediate variables, into a series of elementary functional steps. A library of elementary function subroutines is provided for the automatic evaluation and differentiation of these new variables. The final step in this process produces the desired function's derivative.
The main feature of this approach is its simplicity. It can be used as a quick-reaction tool where the derivation of analytical derivatives is laborious and also as a debugging tool for programs which contain derivatives.
Investigation of a new analytical method for numerical derivative evaluation
A recently proposed analytical approach to numerical derivative evaluation is discussed. The technique is shown to be both accurate and easy to apply, though certain indicated modifications are required. Its use should greatly facilitate the writing and debugging of programs requiring derivatives of highly complex functions.
An automated data system analysis technique is described. The technique is designed to alleviate some of the principal problems that beset current analysis—large data workloads, long span of time between project inception and system operational date, the lack of explicit directions for conducting data system analysis and using the results, and the lack of a technique to control data system changes throughout its lifetime. The analysis is geared to determining workload, relationships and storage characteristics of documents in the information network automatically.
A method for comparing the internal operating speeds of computers
First, a table of frequencies of various types of operations is prepared based on experience in similar applications or, perhaps, on actual counts if these are available. Table 1 shows such a frequency table. Next, the total weighted execution time for a given operation type is obtained by multiplying the time required for the operation by the frequency count. Finally, an “average” operation time is calculated by summing overall operation types and dividing by the sum of the frequency counts. Table 2 shows the computation for the IBM 7090.
Table 3 shows a comparison of average and relative speeds for several current computers for the particular application using the IBM 7090 as a reference base.
Picture generation with a standard line printer
A method is described for producing gray-toned pictures on a line printer by utilizing the different degrees of blackness of standard print characters. Gray scales with 17, 32 and 64 levels have been devised. Scanned images of blood cells are used to display the technique.
Computer-usage accounting for generalized time-sharing systems
The current development of general time-sharing systems requires a revision of accounting procedures for computer usage. Since time-sharing system users operate concurrently, it is necessary to be more precise as to the amount of computer time and storage space that a user actually utilizes. The various cost factors which should be considered for computer usage accounting in generalized time-sharing systems are discussed.
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