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Communications of the ACM

Table of Contents


ACM president's letter: “what's yours?”


A note on storage fragmentation and program segmentation


Recovery of reentrant list structures in SLIP


Prevention of system deadlocks


Generation of test matrices having certain sign patterns and prescribed positive spectra


Polynomial and spline approximation by quadratic programming

The problem of approximation to a given function, or of fitting a given set of data, where the approximating function is required to have certain of its derivatives of specified sign over the whole range of approximation, is …

Generating pseudorandom numbers on a two's complement machine such as the IBM 360

The familiar multiplicative congruential generator is examined in the context of the type of two's complement arithmetic used in the IBM 360 series. Different sequences of residues are considered and relationships established …

Accelerating LP algorithms

It is shown how a novel method for computing (related) inner products can accelerate the pricing phase of LP algorithms. Other LP applications are indicated.

Automatic contour map

Some methods for contour mapping by means of a digital plotter are dicussed, and a new method is presented that is simple enough to be implemented by programs with a rather small number of instructions (about 120 FORTRAN IV instructions …

Some techniques for using pseudorandom numbers in computer simulation

An alogorithm is described by which uniform pseudorandom integers may be used to construct binary “numbers” in which the probability that each bit in the word is a 1-bit and can assume any desired parameter value. Techniques  …

Block structures, indirect addressing, and garbage collection

Programming languages have included explicit or implicit block structures to provide a naming convenience for the programmer. However, when indirect addressing is used, as in SNOBOL, naming constraints may be introduced. Two  …

Algorithm 352: characteristic values and associated solutions of Mathieu's differential equation [S22]


Remark on algorithm 268 [R2]: ALGOL 60 reference language editor


Remark on algorithm 274 [F1]: generation of Hilbert derived test matrix


Remark on algorithm 333 [H]: minit algorithm for linear programming


On obtaining correct input: a new approach


On the expected lengths of sequences generated in sorting by replacement selecting

In the replacement-selecting technique of sorting, one is interested in the ratio Lj of the expected length of the jth sequence generated by the technique to the number of memory cells used. Using complex-variable theory, itj …

Letters to the editor: an implementation of the Tausworthe generator


Letters to the editor: a scheme for specifying running titles