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A note on multiple precision arithmetic
Since computers have means to detect overflow on addition or subtraction, this can be used in a multiple precision addition-subtraction subroutine to obviate a sign analysis. Consider all integers in the computer to be expressed “radix t”, that is, in the form a = a0 + a1t + ··· + antn where ai are of like sign and have magnitudes less than t. t is a positive integer determined by the word length of the computer. Consider the expression c = a ± b = (a0 ± b0) + (a1 ± b1)t + ··· + (an ± bn)tn. Here ai ± bi may exceed the storage capacity of one word or may have a sign different from c.
Glossaries for computing and data processing
At the present time, there is considerable interest and activity in the preparation of a comprehensive glossary of computing and data processing terms. This interest is generated by members of the various national and international professional associations, the computer manufacturers, and the American Standards Association.
An experimental computer program for hypothesis selection
An algorithm for finding the characterization of a class of objects on the basis of a randomly ordered sequence of labeled individual objects—some members of the class, some not—is described. The class is characterized as a disjunction of terms, each term being a conjunction of attributes. “All red, round objects or all square, small objects” is an example. Mechanisms based on this algorithm are described in terms of such properties as the amount of storage available for recording instances and the number of instances which had to be examined until the class was first guessed.
Manned simulation research in complex control systems
Two purposes guide the studies currently in progress in the RAND Logistics Systems Laboratory: one is to aid the Air Force in a substantive management or control problem, such as operations-support control of the ICBM force, or control and allocation of resources to perform the short-term job of procuring, repairing and distributing the Air Force's supply assets; and the second is to improve the RAND use of abstract (primarily, manned computer-assisted) simulations in designing and evaluating alternative, complex control systems.
An algorithm for equivalence declarations
Many algebraic translators provide the programmer with a limited ability to allocate storage. Of course one of the most desirable features of these translators is the extent to which they remove the burden of storage allocation from the programmer. Nevertheless, there are situations in which one wishes to make certain vectors and arrays contiguous, coincident, or overlapping. This is made possible in FORTRAN by the use of COMMON and EQUIVALENCE statements, in MAD by the use of PROGRAM COMMON, ERASABLE, and EQUIVALENCE statements, etc.
Operational compatability of systems—conventions
This project is engaged in (a) a program of research into the application of the concepts and techniques of modern data processing to the design of mechanical parts, and (b) the further development of automatic programming systems for numerically controlled machine tools. The project is a cooperative venture between the Computer Applications Group of the Electronic Systems Laboratory and the Design and Graphics Division of the Mechanical Engineering Department, and is sponsored by the Manufacturing Methods Division of the USAF Air Material Command through Contract AF-33(600)-40604.
On a class of iteration formulas and some historical notes
The class of iteration formulas obtainable by rational approximations of “Euler's formula” is derived with the corresponding error estimates. Some historical notes on iterative procedures are followed by a derivation of Euler's formula with the associated error estimate in a new notation which simplifies the error estimate and suggests generalizations. The final section considers the Padé approximants to the “Euler polynomial” and shows how a number of known formulas may be derived from this unified approach. There is a short discussion of the “best” formula.
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