Artificial Intelligence and Machine Learning
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Time sharing in a traffic control program
The Toronto traffic-signal control system consists of a variety of logically distinct computer programs, all competing for machine time. To satisfy these demands, a time-sharing program has been written whose purpose is to execute, in the order of a predefined priority, the various subprograms within the real-time system. In this paper the more interesting aspects of the time-sharing program are outlined.
A technique for reading gapless tapes makes electrocardiograph analysis feasible on the IBM 7090
To study arrhythmias and higher frequency components of the electrocardiogram, long series of patient heart cycles must be examined before valid comparison of different heart beats can be made. A technique is presented for the automatic analysis of long series heart cycles via a digital computer.
Estimation of heart parameters using skin potential measurements
A fundamental problem of vectorcardiography is the estimation of the state of the heart on the basis of skin potential measurements.
A mathematical model relating ventricular dipoles to surface potentials is sketched. Then it is shown that the inverse problem—that of determining electrical heart parameters on the basis of skin potential measurements—may be viewed as a nonlinear multipoint boundary value problem.
A feasible solution, employing quasilinearization and high-speed digital computers, is given.
A rapid method for digital filtering
Since much of the computer time spent in time-series analysis is used for multiplications, a minimum multiplication method was devised for digital filtering, with the expectation that it would be useful in the online, real-time analysis of biological data. The filters are constructed from a succession of readily analyzable components in a manner that facilitates cascading. The repertoire of frequency response curves includes relatively good low-pass and band-pass designs. Programs are available for implementing both the synthesis of these filters, and their application on computers whose assemblers allow the definition of recursive macros.
Scheduling meetings with a computer
Computer scheduling of papers as it was developed for the 1960 meeting of the Federation of American Societies for Experimental Biology (FASEB) is described. The FASEB meeting is the largest scientific meeting held in the United States each year. The technique developed for FASEB can be applied to schedule any meeting with parallel sessions.
Machine controls for analysis of variance
A major problem in using the analysis of variance, as the number of factors increases, is the exponential rise in the number of interactions. Even though the experimenter may not be interested in these interactions it is impossible to ignore them in most experimental designs because of the problem of getting error terms.
It is natural therefore to look to the computer to handle the bulk of work involved in computing the interactions. A program device to get the computer to do this is described.
A method for scheduling final examinations to yield a minimal number of student conflicts is described. The “minimization” is achieved by repetitively evaluating a nonlinear set of equations. Imbedded in the process is a random or Monte Carlo selection of assignments. As in such heuristic techniques, the solution may not be optimum and many solutions may be found which yield locally minimal results. Computer programs are described and empirical results given.
To increase reliability of transmission between magnetic tape and core storage on an IBM 7090/7094, blocks or records of data are often assigned a word called a logical checksum. This is a number derived from the block by some simple algorithm and as unique to it as possible. The method most commonly used to form a checksum is to add together every datum in the block by the ACL (add and carry logical) instruction.
Techniques for the simulation of computer logic
A special operator calculus developed by Hartley in 1956 together with a new mapping scheme has been found to be efficient in programming analysis of variance for multifactor experiments. The operator calculus and the mapping scheme are described in detail.
Talk—a high-level source language debugging technique with real-time data extraction: 26
TALK, meaning Take A LooK, is a debugging technique which aids substantially in debugging complex real-time programming systems by interrupting the users program at desired points to extract previously specified data. The extracted data is later edited, listing the associated data with its high-level source language identification.
A method for comparing the internal operating speeds of computers
First, a table of frequencies of various types of operations is prepared based on experience in similar applications or, perhaps, on actual counts if these are available. Table 1 shows such a frequency table. Next, the total weighted execution time for a given operation type is obtained by multiplying the time required for the operation by the frequency count. Finally, an “average” operation time is calculated by summing overall operation types and dividing by the sum of the frequency counts. Table 2 shows the computation for the IBM 7090.
Table 3 shows a comparison of average and relative speeds for several current computers for the particular application using the IBM 7090 as a reference base.
A proposal for input-output conventions in ALGOL 60
The ALGOL 60 language as first defined made no explicit reference to input and output processes. Such processes appeared to be quite dependent on the computer used, and so it was difficult to obtain agreement on those matters. As time has passed, a great many ALGOL compilers have come into use, and each compiler has incorporated some input-output facilities. Experience has shown that such facilities can be introduced in a manner which is compatible and consistent with the ALGOL language, and which (more importantly) is almost completely machine-independent. However, the existing implementations have taken many different approaches to the subject, and this has hampered the interchange of programs between installations. The ACM ALGOL committee has carefully studied the various proposals in an attempt to define a set of conventions for doing input and output which would be suitable for use on most computers. The present report constitutes the recommendations of that committee.
Picture generation with a standard line printer
A method is described for producing gray-toned pictures on a line printer by utilizing the different degrees of blackness of standard print characters. Gray scales with 17, 32 and 64 levels have been devised. Scanned images of blood cells are used to display the technique.
Computer-usage accounting for generalized time-sharing systems
The current development of general time-sharing systems requires a revision of accounting procedures for computer usage. Since time-sharing system users operate concurrently, it is necessary to be more precise as to the amount of computer time and storage space that a user actually utilizes. The various cost factors which should be considered for computer usage accounting in generalized time-sharing systems are discussed.
The FORTRAN II CHAIN feature on the 7090 can be used to save card-to-tape time, loading time, and to provide a convenient method for storing and transporting producting programs. The method is simply to load the desired program as a CHAIN and save the tape on which it is stored. A trivial program can then be used to recall the major program.
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