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Apr 1 1965

Numerical integration of a differential-difference equation with a decreasing time-lag

Systems in which variable time-lags are present are of common occurrence in biology. Variable flow rates are a common cause of these variable lags. At present no extensive body of knowledge exists concerning the effects which these variable lags can cause. Shown here is a method of reducing some differential-difference equations to ordinary differential equations which can then be studied numerically with ease. Subsequent study will deal with situations in which multiple-lags and lags dependent on the solution itself are present.
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Apr 1 1965

Transparent-mode control procedures for data communication, using the American standard code for information interchange—a tutorial

This paper gives the considerations of Task Group X3.3.4 in the area of transparent-mode data communication control philosophy. The appearance of this paper was forecast (under the name of “second-level control”) in the earlier tutorial paper, “Control Procedures for Data Communications,” Task Group document X3.3.4.44, dated May 1964. The present paper elaborates upon solutions to the problems of transparency to the basic ASCII communication control characters, as outlined in the previous paper mentioned above. Moreover, it goes on to cover the additional control problems of handling material such as offline encrypted data or non-ASCII codes by means of systems providing complete character transparency. It does not cover concepts of transparency in which the normal character structure or modulation rate of a system may be abandoned. In conjunction with the earlier tutorial paper, this paper is expected to lead to a proposal for standardization of data communication control procedures using the American Standard Code for Information Interchange.
Architecture and Hardware
Apr 1 1965

Wengert’s numerical method for partial derivatives, orbit determination and quasilinearization

In a recent article in the Communications of the ACM, R. Wengert suggested a technique for machine evaluation of the partial derivatives of a function given in analytical form. In solving nonlinear boundary-value problems using quasilinearization many partial derivatives must be formed analytically and then evaluated numerically. Wengert's method appears very attractive from the programming viewpoint and permits the treatment of large systems of differential equations which might not otherwise be undertaken.
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Apr 1 1965

Still another use for FORTRAN II chaining

This is to report a further use of the FORTRAN II Chain System. We, at Sandia, have modified the Chain subroutine to allow for picking up chains from the disk instead of a chain tape. The major change was the addition of a job identification to each chain system, thus allowing for different chain jobs with the same chain number to be available from the disk at any time.
Computing Applications
Apr 1 1965

The use of COBOL subroutines in FORTRAN main programs

If a problem requires both complicated calculations and edited output printing, then the computing part can be efficiently handled in FORTRAN and the editing part, e.g. punctuation, check protect and floating dollar sign, can be conveniently done in COBOL, in particular by the PICTURE clause. The following programs illustrate the simple technique of combining FORTRAN and COBOL. The main program is written in FORTRAN and the subroutine in COBOL. The programs were run on IBM 7090.
Computing Applications
Apr 1 1965

Expanding the editing function in language data processing

In automatic abstracting, citation indexing, mechanical translation and other such procedures, editing is required whenever the automatic method leaves something to be desired. This paper discusses the economy of editing as a function of the amount of condensation of text in language processing operations, and then contends that editing can be regarded as an opportunity rather than as an unwelcome necessity. “Heavy editing,” which goes beyond mere correction and improvement of computer output, is exemplified by the use of a concordance in preparing a survey article or lecture. Other opportunities for heavy editing are described, chief among them being interpretation and expansion of computer output in such processes as factor analysis. Applications are described, such as the quick, unbiased evaluation of a large volume of incoming mail or telegrams, yielding summary reports not possible for either humans or computers to produce alone.
Computing Applications
Apr 1 1965

Data input by question and answer

A data input scheme for a time-sharing computer is described in this paper. Instead of using format statements to determine the input, the computer asks the user for the required values one at a time. The computer converses with the user during the input process, checks for errors, provides standard data, and allows editing of values input.
Computing Applications
Apr 1 1965

The use of FORTRAN in subroutines with COBOL main programs

By using the proper COBOL coding techniques and accounting for differences in storage allocation and library routines between the two languages, it is possible to write FORTRAN IV subroutines that may be called from COBOL main programs. Such a technique enables the programmer to take advantage of the most useful properties of each language while minimizing their respective disadvantages.
Computing Applications

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