Computing Applications
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An undergraduate program in computer science—preliminary recommendations
The Curriculum Committee on Computer Science (C3S) of the Association for Computing Machinery has been considering curriculum problems for approximately three years. During the early part of this period, a number of informal sessions were held with computer people at various national meetings. In the latter part of this three-year period, the Committee has been formally organized and has made a definite effort to arrive at a concrete suggestions for a curriculum.
Applications of differential equations in general problem solving
A large class of problems leading to digital computer processing can be formulated in terms of the numerical solution of systems of ordinary differential equations. Powerful methods are in existence for the solution of such systems. A good general purpose routine for the solution of such systems furnishes a powerful tool for processing many problems. This is true from the point of view of ease of programming, ease of debugging, and minimization of computer time. A number of examples are discussed in detail.
On reversible subroutines and computers that run backwards
A computer design is described which permits subroutines to be executed backward as well as forward, either with their instructions unchanged or replaced with conjugate instructions. It is shown that using this concept a number of new subroutine types can be developed with rather unusual properties. Since these properties are analogous to certain matrix operations, a arallel nomenclature is suggested for their classification.
ACM proposes to republish contents of Communications Algorithms section is useable looseleaf format, with bimonthly updating service, provided there is sufficient demand. For details, see News item on page 583.
UPLIFTS—University of Pittsburgh linear file tandem system
A series of computer programs has been developed and is now operational for processing the National Aeronautics and Space Administration linear file system on an IBM 1401-7090 combined data processing system. The programs are noteworthy in that they create fixed length logical records and fixed length blocks from variable length source data, and format the output for optimization of processing on the IBM 7090 system. The programs are completely self-checking and test for both validity and accuracy of the input materials as provided by the National Aeronautics and Space Administration.
A computer center simulation project
Today's computation centers are based on rapidly changing technologies of hardware and software systems. It is difficult, therefore, to base decisions on experience; in most instances, the benefits of comparable experience for a given problem situation are not available. In this paper, a mathematical model of the Lockheed Central Computer Center is formulated that describes the operation of a computation center in terms of information nets, decision processes, and control functions. Experiments performed with this model, the results of the experiments, and the application of the results are discussed.
Negative and zero subscripts in Fortran II programming for the IBM 1620
The requirement that subscripts be unsigned integers creates some inconvenience in FORTRAN programming for summarization of completed questionnaires in which the responses may be scaled beginning at zero.
Some experiments in algebraic manipulation by computer
A set of subroutines to allow algebraic manipulations on the IBM 7094 computer has been written using a List Processor, SLIP.
A series of four problems of increasing difficulty were solved using these routines.
A method for storing strings is described which uses blocks of indefinite size, and is therefore completely dynamic. Its relation to similar schemes is discussed.
Remarks on simulation of Boolean functions
Recently M. Morris Mano presented a method for performing Boolean OR, AND and NOT operations by means of arithmetic and conditional transfer operations in a decimal computer lacking builtin logical instructions [1]. When A, B, C are variables whose defined value is 0 or 1 and a, b, c are the corresponding integer variables with values 0 or 1, his Boolean OR was defined by:
“The result of an OR operation of Boolean variables is the same as the arithmetic addition of the a, b, c integer variables after which the following test is made: (a) If the sum is equal to zero, the result is correct; (b) If the sum is larger than zero, the answer is 1.”
Symbolic derivatives without list processing, subroutines, or recursion
A routine has been developed which computes and prints out the symbolic derivative of an absolutely continuous elementary function of one or several variables. No use is made of list processing languages. The chain rule is applied and the result is edited to produce results as elegant and efficient as those obtained by hand computation. A subset may be imbedded in a formula translator to introduce a differentiation operator into an “algebraic” programming language.
Simulation of computer logic by Fortran arithmetic
During the preliminary logical design of the NEBULA computer for the Oregon State University Department of Mathematics, it was decided to simulate the logic equations on one of the computers available on campus. Thus most of the logic could be debugged prior to backwiring.
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