By Topic

Electronic Computers, IEEE Transactions on

Issue 6 • Date Dec. 1967

Filter Results

Displaying Results 1 - 25 of 36
  • [Front cover]

    Publication Year: 1967 , Page(s): c1
    Save to Project icon | Request Permissions | PDF file iconPDF (471 KB)  
    Freely Available from IEEE
  • IEEE Computer Group

    Publication Year: 1967 , Page(s): nil1
    Save to Project icon | Request Permissions | PDF file iconPDF (166 KB)  
    Freely Available from IEEE
  • Breaker Page

    Publication Year: 1967 , Page(s): nil1
    Save to Project icon | Request Permissions | PDF file iconPDF (166 KB)  
    Freely Available from IEEE
  • The Use of Hybrid Computing in the Analysis of Steel Rolling

    Publication Year: 1967 , Page(s): 717 - 722
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (767 KB)  

    The equations that govern the behavior of steel under-going reduction are complex differential equations. A method of solving these equations using a hybrid computer is described, and the peculiar problems associated with such a solution are discussed. In the hybrid implementation, differential equations can be solved very fast, and the speed of solution is governed by the number of samples one requires of the trajectory from the analog computer for useful computation in the digital computer. Thus, methods are described whereby the number of samples taken can be reduced and the accuracy of the manipulations performed by the digital computer can still be maintained. The results obtained are both accurate and rapid, and the system has the normal engineering appeal of a purely analog solution. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Device Applications of Charge Rectifiers

    Publication Year: 1967 , Page(s): 723 - 731
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3476 KB)  

    Two circuit models of a semiconductor junction rectifier are presented. For times long compared to the effective minority carrier lifetime, the usual current rectifier concept obtains. For times short compared to the lifetime, a charge rectifier is better able to explain experimental results; reverse recovery is evidence of this. Viewed in this way, semiconductor junctions are suitable for certain types of digital information processing. Voltage gain is limited only by junction breakdown and driver capability but charge (current) gain is inevitably less than one. The amount of charge run-down is shown to depend on the time the information is in the circuit. Scan generators, shift registers, serial memories, and serial converters have been studied as examples of the wide range of applications for which these devices are suitable. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spectrum Analysis of Digital Magnetic Recording Waveforms

    Publication Year: 1967 , Page(s): 732 - 743
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1925 KB)  

    Closed form expressions have been obtained for the power density spectra of signal waveshapes in use for digital magnetic recording. The ``signal'' is the magnetization versus distance profile imposed on the magnetic medium to encode binary ones and zeros. Two general classes of signals are distinguished in terms of neighboring bit-to-bit correlation. Standard recording methods such as saturation NRZ and phase modulation are considered, as well as techniques requiring bias current, such as sinusoidal frequency-shift modulation. The spectra are compared with frequency response curves for the reading head at several recorded bit densities. The more ideal bandwidth characteristics of the newer phase- and frequency-modulation techniques help to explain their improved performance at high bit densities. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Crosstalk (Noise) in Digital Systems

    Publication Year: 1967 , Page(s): 743 - 763
    Cited by:  Papers (46)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6799 KB)  

    As digital system speeds increase and their sizes diminish, it becomes increasingly important to understand the mechanism of signal crosstalk (noise) in interconnections between logic elements. The worst case is when two wires run parallel for a long distance. Past literature has been unsuccessful in explaining crosstalk between parallel wires above a ground plane, because it was assumed that only one signal propagation velocity was involved. This paper proves that a signal introduced at one end of a printed wire above a ground plane in the presence of a second parallel (passive) wire must break up into two signals traveling at different velocities. The serious crosstalk implications are examined. The new terms slow crosstalk (SX), fast crosstalk (FX) and differential crosstalk (DX) are defined. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance Evaluation of Computing Systems with Memory Hierarchies

    Publication Year: 1967 , Page(s): 764 - 773
    Cited by:  Papers (7)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1694 KB)  

    Data transfers in computing systems with memory hierarchies usually prolong computing time and, consequently, cause degradation of system performance. A method to determine data processing rates and the relative utilization of memories for various system configurations under a variety of program loads is presented. According to this method, a program-independent ultimate data processing rate is derived from characteristics of the processor and the fastest random access memory of the system, and degradation factors are determined by combining statistics of the data flow of actual programs and hardware parameters of the processor and all memories. The statistics of data flow in the memory hierarchy are obtained by analyzing a number of recorded address traces of executed programs. The method presented permits quick evaluation of system performance for arbitrary time periods and for maximum and minimum concurrence of operation of processors and memories. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • ``Intergraphic,'' A Microprogrammed Graphical-Interface Computer

    Publication Year: 1967 , Page(s): 773 - 784
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2194 KB)  

    The paper describes a proposed microprogrammed interface computer, ``Intergraphic,'' which will link many (initially 13; potentially more than 50) general-purpose graphical terminals to a central processor. Intergraphic will generate new images once only, at high speed (10-MHz incremental plotting rates) on one of several small, electrostatically deflected, precision CRT's. The images will be generated on a 1024 by 1024 grid in incremental and random-point display modes by fast microcode sequences which interpret display lists from the central processor. The centrally generated images will be scan converted to standard television video signals and recorded on a multitrack video disk(s), each track refreshing a low-cost standard television terminal. User feedback will be via raster coordinates, determined by a light-pen (``raster-pen'') and simple counting circuits at each terminal. The paper concentrates on the digital interface structure which is versatile and fast (3-5 ns integrated circuits and 100-ns cycle-time READ-only memory). The description centers on display generation, although the structure is largely general purpose. The proposed operating system is outlined only since it is in an early stage of development. Also, the order-code accompanying data from the central processor is incomplete. However, new orders can be readily interpreted by adding microprograms to the READ-only memory (i.e., ``firmware,'' not hardware extensions); thus, the interface will also be a useful medium for experimentation in graphical structures and communication. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Algorithm for the Solution of the Two-Dimensional ``Hidden-Line'' Problem

    Publication Year: 1967 , Page(s): 784 - 790
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1184 KB)  

    The two-dimensional ``hidden-line'' problem is the problem of determining, by means of a computer algorithm, which edges or parts of edges of an arbitrary, nonintersecting polygon are visible from a specified vantage point in the plane of the polygon. The problem is an important one in the field of computer graphics, and is encountered, for example, in using a computer to determine the portion of an island's coastline visible from a ship offshore. Some propositions are introduced that facilitate the solution of this problem. A general algorithm for the solution is described, and illustrative examples are given of hidden-line problems solved with a digital computer. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Dynamic Programming Approach to Sequential Pattern Recognition

    Publication Year: 1967 , Page(s): 790 - 803
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2029 KB)  

    This paper presents the dynamic programming approach to the design of optimal pattern recognition systems when the costs of feature measurements describing the pattern samples are of considerable importance. A multistage or sequential pattern classifier which requires, on the average, a substantially smaller number of feature measurements than that required by an equally reliable nonsequential classifier is defined and constructed through the method of recursive optimization. Two methods of reducing the dimensionality in computation are presented for the cases where the observed feature measurements are 1) statistically independent, and 2) Markov dependent. Both models, in general, provide a ready solution to the optimal sequential classification problem. A generalization in the design of optimal classifiers capable of selecting a best sequence of feature measurements is also discussed. Computer simulated experiments in character recognition are shown to illustrate the feasibility of this approach. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Identification of Symmetry, Redundancy and Equivalence of Boolean Functions

    Publication Year: 1967 , Page(s): 804 - 817
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2450 KB)  

    Functionally packaged logic can only be effectively utilized if the totality of switching functions that each package is capable of providing is recognized. Theorems concerning, and algorithms operating on, multiple output switching functions (possibly with don't care conditions) in cubical array notation are presented that 1) detect partial symmetry and redundancy sets of input varibles, 2) determine the function generated by a package with some of its inputs tied to logical 1 or 0 or tied together, and 3) rapidly show equivalence between two functions using symmetry information. While manual execution of the algorithms is possible, they are computer oriented. Results from actual computer experimentation show their efficiency. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Threshold Logic Network for Shape Invariance

    Publication Year: 1967 , Page(s): 818 - 828
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2047 KB)  

    A property filter is developed that is suitable for recognizing translation-rotation-dilation classes of two-dimensional images. Invariant outputs corresponding to such classes are obtained by employing two successive sampled spatial harmonic transforms. The required analyses are equivalent to taking inner products of pairs of vectors only one of which is variable in each case. Subsequently, the necessary network may be realized with fixed threshold logic, independent of the character classes to be recognized. The effectiveness of the property filter has been confirmed with printed and handwritten numerals by coupling it to a standard adaptive categorizer of a type assuming linear separability. There is further evidence to show that performance is improved by coupling a categorizer that does not assume linear separability. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Realization Procedure for Multithreshold Threshold Elements

    Publication Year: 1967 , Page(s): 828 - 835
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1472 KB)  

    A synthesis procedure is introduced for obtaining multithreshold threshold-element realizations of arbitrary Boolean functions (including functions with don't cares). Through transforms of multithreshold threshold-element realizations, the procedure is also applicable to threshold-element-network realizations of functions. The procedure is useful for hand calculations for functions with a small number of variables, and has been programmed on a computer for functions having up to 11 variables¿the number of variables is presently limited by storage allocation. The function to be realized is first completely decomposed about its variables to form a tree. The functions resulting at the tips of the tree branches from the complete decomposition have simple ``value functions'' (which specify a set of multithreshold realizations) that are uniquely determined by the weight chosen for the final variable in the decomposition. After choosing this weight, the given function is systematically reconstructed from the tree by choosing the weight of one variable at a time through the combined use of a theorem that specifies the allowable weights of the new variable and an analysis of the minimum possible number of thresholds required as a result of a given allowable weight. Experimental results of hand and computer calculations show the procedure to be fast in producing realizations with a small number of thresholds and a small sum of weight magnitudes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimization of Reduced Dependencies for Synchronous Sequential Machines

    Publication Year: 1967 , Page(s): 835 - 847
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2658 KB)  

    The purpose of this paper is to describe an algorithmic ``solution'' to the assignment problem of synchronous sequential machines. The figure of merit used provides a mathematical evaluation of the reduced dependencies that may exist in the set of logic equations. If desired, the algorithm can assign the input, state, and output symbols of a given machine so as to ``minimize'' the total logic, i.e., reduced dependencies of both the state and output logic on state and input variables are optimized. The method is nonenumerative in the sense that the first assignmnent found is optimal. A restricted version of the algorithm has been programmed for an IBM 7094 computer. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the Connection Assignment Problem of Diagnosable Systems

    Publication Year: 1967 , Page(s): 848 - 854
    Cited by:  Papers (427)  |  Patents (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1326 KB)  

    This paper treats the problem of automatic fault diagnosis for systems with multiple faults. The system is decomposed into n units u1, u2, . . . , un, where a unit is a well-identifiable portion of the system which cannot be further decomposed for the purpose of diagnosis. By means of a given arrangement of testing links (connection assignment) each unit of the system tests a subset of units, and a proper diagnosis can be arrived at for any diagnosable fault pattern. Methods for optimal assignments are given for instantaneous and sequential diagnosis procedures. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modified Pseudorandom Number Generators

    Publication Year: 1967 , Page(s): 854 - 856
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (698 KB)  

    Pseudorandom number generator programs can be modified by a simple procedure which has particular advantages for the shorter word binary computers. The method combines the result of any conventional arithmetic generator with the current state of counters by means of a logic instruction. A variety of statistical tests have indicated that good results are realized. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On-Line Computer Classification of Handprinted Chinese Characters as a Translation Aid

    Publication Year: 1967 , Page(s): 856 - 860
    Cited by:  Papers (9)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2854 KB)  

    This paper describes a method for using sequential positional information to recognize handprinted Chinese characters, and a computer program which uses this method to provide a translation aid. The method is based on the fact that Chinese characters are drawn as a definite sequence of a few types of strokes. The program, which provides a direct man-computer communication via a RAND Tablet and a CRT display, simplifies using a Chinese dictionary by reducing the number of steps and the time required. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Experimental Investigation of a Nonsupervised Adaptive Algorithm

    Publication Year: 1967 , Page(s): 860 - 864
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1195 KB)  

    An unsupervised or nonsupervised adaptive algorithm for linear decision boundaries is applied to two pattern recognition problems: the classification of spoken words, and the classification of hand-printed characters. The term unsupervised indicates that the class identification of the input patterns is not continuously available to the adaptive system. The algorithm discussed offers two advantages for pattern recognition applications. First, the number of patterns which must be labeled with class identification is reduced. Second, the adaptive system can follow changes in the class distributions over time, due to data fluctuation or hardware degradation. These advantages are demonstrated for each of the two applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of Mean Shift for a Binary Multiplier Using 2, 3, or 4 Bits at a Time

    Publication Year: 1967 , Page(s): 864 - 866
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (579 KB)  

    Binary multiplication can be speeded up by taking two or more bits of the multiplier at a time. This note describes an exact method, based on the use of a discrete-time, finite-state system model, for calculating the gain in multiplication speed resulting from such a scheme. It is shown that the gain in speed is less than what had previously been obtained using an approximation formula. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Adaptive Coding for Self-Clocking Recording

    Publication Year: 1967 , Page(s): 866 - 868
    Cited by:  Papers (10)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (683 KB)  

    Self-clocking of binary information involves a coding constraint whereby the maximum length of zero strings is limited to a predetermined number. For reasons of operational stability it is desirable to keep this number low. The price of such constraint is a degradation in code density. The class of serial recording which includes the well-known frequency modulation and phase encoding represents one extreme where every other symbol is mandatory, making the code density one bit for every two symbols. This paper describes a coding method which improves code efficiency while maintaining the constraint on the length of zero strings. It will be shown that adaptive coding, which is an extension of the block code concept known from information theory, offers a significant improvement. The concept is illustrated by describing a practical application in which the code density is improved from two symbols per bit to three symbols per bit pair, while keeping the maximum length of zero strings to one. It is shown that while this technique represents an improvement by one third over phase encoding, it approaches the theoretical limit for this class of codes to within 4 percent. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Testing and Realization of Threshold Functions with Don't Cares

    Publication Year: 1967 , Page(s): 868 - 870
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (721 KB)  

    In this note the successive-higher-ordering method for testing and realization of threshold functions is applied to the realization of a threshold function F, such that it will contain a given function F1, which may or may not be a threshold function, and such that it will be contained in F1+F¿, where F¿ is the function representing the don't care vertices. Before the application of the successive-higher-ordering method, the given functions F1 and F¿ = (F1+F¿) are first changed into unate functions by the successive positivizing of the functions with respect to the variables, one at a time. Some theorems relating to this formation of unate functions are presented. A systematic procedure for testing and realization is developed. An example is given for illustration. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Rapid Method for the Identification of the Type of a Four-Variable Boolean Functin

    Publication Year: 1967 , Page(s): 870 - 871
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (383 KB)  

    The hyperoctahedral group on the set of N-variable Boolean functions is defined. The problem of determining, given an arbitrary function, its equivalence class membership (type) is posed and, for the special case of four-variable functions, solved by a method that in use proved to be four times as rapid as computation of the conventional Golomb-Ninomiya[1],[2] invariants. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Random Noise Generation by Hybrid Computer

    Publication Year: 1967 , Page(s): 872 - 873
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1087 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contributors

    Publication Year: 1967 , Page(s): 873 - 876
    Save to Project icon | Request Permissions | PDF file iconPDF (4037 KB)  
    Freely Available from IEEE

Aims & Scope

This Transactions ceased publication in 1967. The current retitled publication is 

IEEE Transactions on Computers.

Full Aims & Scope