 # Communications of the ACM

#### A fast procedure for generating normal random variables

A technique for generating normally distributed random numbers is described. It is faster than those currently in general use and is readily applicable to both binary and decimal computers.

#### Floating-point arithmetic with 84-bit numbers

A classic and straightforward technique is presented which is not limited to the size or type of number representation used or multiple precision arithmetic.

#### A note on multiplying boolean matrices II

In a note by Baker , a method is given for getting the limiting connectivity matrix, B, of a matrix whose entries are Boolean 0's and 1's. Harary  suggests determining An-1 since An-1 = An = ··· , wheren is the order of …

#### An example in “significant-digit” arithmetic

Different methods of handling the summing process for the geometric series are shown to give results indicating widely differing significances when carried out in a machine incorporating “significant-digit” arithmetic.

#### On the numerical solution of boundary value problems for linear ordinary differential equations

A numerical method is presented for the solution of boundary value problems involving linear ordinary differential equations. The method described is noniterative and makes use of any one-step numerical integration scheme to  …

#### An efficient composite formula for multidimensional quadrature

A (2s+1)-point, second-degree quadrature formula for integration over an s-dimensional hyper-rectangle is presented. All but one of the points lie on the surface with weights of opposite sign attached to points on opposite faces …

#### GIT—a heuristic program for testing pairs of directed line graphs for isomorphism

Given a pair of directed line graphs, the problem of ascertaining whether or not they are isomorphic is one for which no efficient algorithmic solution is known. Since a straightforward enumerative algorithm might require 40partially …

#### Digital computer determination of alpha source activity

A technique is described for determining the activity and homogeneity of an alpha source. It is believed that the technique, using a digital computer, has many uses and applications in the field of nuclear physics. The technique …

#### Analysis of decay-type data

A comparative study has been made of a variety of numerical techniques for fitting experimental data of the decay type by forms involving the sums of exponentials. Statistical errors of the fitted parameters are also calculated … Previous Issue Next Issue