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Computers and Digital Techniques, IEE Journal on

Issue 6 • Date December 1979

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Displaying Results 1 - 9 of 9
  • Adaptive-channel-capacity store-and-forward buffers

    Page(s): 233 - 236
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (413 KB)  

    A store-and-forward message-switching system is considered, in which the capacity of a channel can be changed dynamically in response to the number of messages awaiting transmission. Three different control strategies are considered. In one, the channel capacity is decided at fixed intervals of time; in the second, the interdecision intervals are random but conform to a fixed distribution; in the third, the decision is made on the arrival and departure of each message. The three strategies are analysed and compared. View full abstract»

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  • Modular networks for direct processing of delta-modulated signals

    Page(s): 237 - 243
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (722 KB)  

    Modular networks for arithmetic signal processing are described for operation with delta-modulated input and output signals. It is shown that designs based on the concept of the digital delta-modulation encoder provides a flexible approach to implementation of arithmetic units using full adders and flip-flops encompassing both serial and parallel forms. Schemes for the elementary operations of addition and multiplication by a constant coefficient are presented and maximum quantisation error is determined. The effect of input errors when the elementary unit is embedded in a larger network is also discussed including idling sequences introduced at the inputs as approximations to zero. Networks for signal mixing and digital filtering are developed by combining elementary units and the complexity and maximum quantisation error of each are determined. It is shown that in most cases greater economies in hardware and/or less quantisation error can be achieved in comparison with existing techniques. View full abstract»

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  • Identification of multidimensional time series and its application in computer graphics

    Page(s): 244 - 250
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (668 KB)  

    This paper extends the well-known technique of linear signal analysis by predictive filtering to the case where the signals are multidimensional. The properties of the simplest possible multidimensional filter, with a 2-dimensional input and of first order, are examined in detail. It is shown that such filters generate linearly deformed logarithmic spirals, including conies as a special case. The technique can be used to identify segments of such curves drawn freehand in a computer graphics environment; and a system which incorporates it is described. One of the most useful features of the system is its ability to transform the curve by controlling the amount of spiralling, rotation, scaling and translation, on command from the user; this is easy to do because the geometric properties can be calculated from the predictive filter coefficients. View full abstract»

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  • Segmentation of terrain images using textural and spectral characteristics

    Page(s): 251 - 259
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1556 KB)  

    A method is presented for the segmentation of serial photographs of terrain on the basis of textural as well as spectral characteristics. The method addresses the problems of determining an optimum texture window size, avoiding misclassified areas near region boundaries (owing to the texture window overlapping two or more regions), and coping with textured and untextured regions co-existing in the same scene. The technique is illustrated by an example. View full abstract»

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  • Tabular method for evaluation of incomplete address decoding in microprocessor systems

    Page(s): 260 - 262
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    A tabular method is described which permits immediate evaluation of the consequences of incomplete address decoding in microprocessor systems. The method is easy to apply and aids microprocessor system design in several ways: (a) the minimal address decoding requirements for a given system can be readily determined (b) undesirable simultaneous addressing of more than one device is avoided (c) address ranges which are available for system expansion are immediately apparent (d) if the available ranges are inadequate, the required additional decoding is readily determined. View full abstract»

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  • 5th Symposium on microprocessors and microprogramming

    Page(s): 263 - 264
    Save to Project icon | PDF file iconPDF (330 KB)  
    Freely Available from IEEE
  • 6th annual symposium on computer architecture

    Page(s): 264 - 265
    Save to Project icon | PDF file iconPDF (332 KB)  
    Freely Available from IEEE
  • Ada workshop

    Page(s): 265 - 267
    Save to Project icon | PDF file iconPDF (482 KB)  
    Freely Available from IEEE
  • 4th international conference on software engineering

    Page(s): 267 - 268
    Save to Project icon | PDF file iconPDF (292 KB)  
    Freely Available from IEEE