Electrical Engineers, Proceedings of the Institution of

Issue 3.4 • March-April 1971

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Displaying Results 1 - 25 of 40
  • Simple estimators for error probability in simulation studies of digital communication systems

    Publication Year: 1971, Page(s):397 - 400
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (445 KB)

    The paper describes the application of some statistical estimation techniques to the problem of evaluating the probability of error of (digital) communication systems. The usefulness of an estimator is governed by the variance of the estimate, which, in this case, is the measured probability of error. It is shown that, for the low values of probability of error considered to be practically useful,... View full abstract»

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  • Subjective evaluation of unsuppressed echo in simulated long-delay telephone communications

    Publication Year: 1971, Page(s):401 - 408
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1040 KB)

    The paper describes an experiment to measure the subjective effect of unsuppressed echo to determine the improvement in echo return loss required of echo cancellers in long-delay telephone communications. Using a simulated long-delay telephone connection of 16.5 dB nominal overall reference equivalent, tests were carried out over a range of conditions in which the 1-way delay varied between 50ms a... View full abstract»

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  • Limitations of error-detection coding at high error rates

    Publication Year: 1971, Page(s):409 - 416
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1239 KB)

    The paper seeks to justify the contention that the efficiency of error-detection-coding techniques is frequently overestimated owing to insufficient appreciation of the interaction between the characteristics of the code and those of the signalling channel itself. The redundancy of an error-detection code (e.d.c.) requires an increase in modulation rate, and this causes an increase in element erro... View full abstract»

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  • Correlation-recovered adaptive majority multiplexing

    Publication Year: 1971, Page(s):417 - 422
    Cited by:  Papers (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (714 KB)

    A novel method of multiplexing based on a pattern-recognition technique is described, in which binary data are combined for transmission over a common medium by modulation onto binary codewords. A majority-logic gate forms the transmitted (binary) signal from the modulated codewords. Demodulation is effected by a correlation process using digital matched filters. The system exhibits an adaptive pr... View full abstract»

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  • Loudness ratings of telephone speech paths

    Publication Year: 1971, Page(s):423 - 436
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (2094 KB)

    Telephone engineers rely a great deal on loudness ratings of speech paths for the framing of national transmission plans and for international recommendations to secure proper co-ordination between national networks. Loudness ratings for such use are, by convention, based on subjective loudness comparisons against a specified high-quality reference system (NOSFER), and the measurements are difficu... View full abstract»

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  • Application of fourier techniques to computer-aided design of electronic systems

    Publication Year: 1971, Page(s):437 - 446
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1424 KB)

    At an early stage in the design of electronic systems, decisions have to be made concerning the function and performance of certain vital elements in the main signal path of the system, such as modulators and crucial filters. WASP (waveform and spectral-analysis program) is a computer program which allows the user to analyse a proposed system of cascaded modules and to extract the waveform and spe... View full abstract»

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  • IEE Scottish Electronics & Control Section: Chairman's address. Public telecommunication in Britain

    Publication Year: 1971
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (144 KB)

    First Page of the Article
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  • Automatic compensation in colour television cameras for changes in scene illuminant

    Publication Year: 1971, Page(s):449 - 459
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1408 KB)

    Prototype equipment is described which automatically corrects the colour balance of a colour television camera for changes in the scene illuminant. The performance of this equipment, which is assessed over a wide range of illuminants, shows that a satisfactory degree of automatic control may be obtained in practice. View full abstract»

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  • Electronic field-store standards convertor

    Publication Year: 1971, Page(s):460 - 468
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1337 KB)

    An electronic field-store standards convertor is described which converts colour-television signals on the American 525-line standard to signals on the European 625-line standard. The convertor was first introduced into service by the BBC to give coverage of the Mexico City Olympic Games. View full abstract»

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  • Design of complex microstrip circuits by measurement and computer modelling

    Publication Year: 1971, Page(s):469 - 474
    Cited by:  Papers (11)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (794 KB)

    Measurement techniques have been developed which allow the complex admittance existing at a nominal microstrip open circuit to be accurately characterised. This information, together with the line loss and wavelength, has enabled the electrical defining plane of a shunt stub to be determined. By using a circuit-design technique based on computer modelling it is possible to allow for all these fact... View full abstract»

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  • Use of tests at elevated temperatures to accelerate the life of an m.o.s. integrated circuit

    Publication Year: 1971, Page(s):475 - 485
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1546 KB)

    Assurances of a long service life will often be demanded of m.o.s. integrated circuits used in telecommunication equipment. An attempt has accordingly been made to identify failure risks and devise life-prediction procedures by accelerated testing, ambient temperature being the primary stress variable. The test vehicle, manufactured on a volume production line, had a simple circuit configuration p... View full abstract»

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  • Analogue recursive computer

    Publication Year: 1971, Page(s):486 - 492
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (937 KB)

    A control computer is described which uses a serial digital program to control an arithmetic unit and storage system working entirely in the analogue mode. Storage is capacitive, using field-effect-transistor switches for data selection. Using conventional techniques, speeds of 20μs per arithmetic operation are readily obtainable. The first application of this computer is to aircraft-gas-t... View full abstract»

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  • Design of large high-speed floating-point-arithmetic units

    Publication Year: 1971, Page(s):493 - 498
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (858 KB)

    An investigation of the design philosophy of large floating-point -arithmetic units has been undertaken, with a view to establishing the principles for constructing such a unit for a large high-speed computing system. The main consideration applied was maximum speed for a reasonable cost in a machine handling numbers 30-64 bits in length. Consideration of compatibility with other systems was speci... View full abstract»

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  • Design of large high-speed binary multiplier units

    Publication Year: 1971, Page(s):499 - 505
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (786 KB)

    An attempt has been made to review the methods of multiplication available for use in a large high-speed computing machine. Number lengths of 50 to 60 bits and multiplicatiion times of less than 0.5 μs were the design aims. Suitable multiplier units will make use of carry-save adders to reduce the time for each addition cycle, and will decode several multiplier bits in each cycle to reduce... View full abstract»

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  • Theory of cylindrical antennas in conducting media

    Publication Year: 1971, Page(s):507 - 510
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (442 KB)

    A method is presented for analysing isolated symmetrical dipoles and two such parallel nonstaggered dipoles immersed in a homogeneous conducting medium. The results obtained by the present theory are in good agreement with experimental results. The theory is restricted to relatively thin dipoles, and the lengths of the dipoles should not considerably exceed the operating wavelength measured in the... View full abstract»

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  • Simple method of antenna analysis leading to the mode-theory results

    Publication Year: 1971, Page(s):511 - 514
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (445 KB)

    A method of antenna analysis is presented which gives the current distribution and input impedance of finite conical antennas. The results for the impedance are identical with those obtained from the 'mode theory', but the results for the current have the advantage that they are found in closed form. In addition, the method is much more easily applied. A very general method of obtaining the charac... View full abstract»

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  • Ground-interference pattern of 16kHz radio waves during summer days

    Publication Year: 1971, Page(s):515 - 518
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (391 KB)

    Results are presented from measurements of the signal strength made in an aircraft flying northwards from the 16kHz transmitter GBR, Rugby, England, on four days in June 1969, near the epoch of maximum, solar activity. The interference pattern due to the combination of ground and sky waves is found to change significantly with local time, whereas the change between different days at the same local... View full abstract»

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  • High-power radar for meteorological stuides in clear air

    Publication Year: 1971, Page(s):519 - 528
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1733 KB)

    A very high-sensitivity S band radar capable of detecting targets with radar cross-section of 5 × 10-10 m2 of reflectivities of 2 × 10-15 m-1 at a range of 10km has recently been brought into operation for meteorological studies of the clear atmosphere. The paper outlines the constraints set by the meterological requirements, and describes the ... View full abstract»

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  • Airgap winding for large turbogenerators

    Publication Year: 1971, Page(s):529 - 535
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1069 KB)

    Modern turbogenerators have large airgaps for system stability. This airgap space can be used to accommodate the a.c. windings of the machine, instead of placing them in slots. In the paper, the disadvantages of windings in slots are discussed, together with problems that will result from putting the winding in the airgap. Using a published design for a conventional 750 MW machine and converting t... View full abstract»

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  • IEE North Staffordshire Sub-Centre: Chairman's address. L.V. motor-control centres; their development and some design aspects

    Publication Year: 1971
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (133 KB)

    First Page of the Article
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  • Induction-motor speed-control schemes employing stator-voltage variation and pole-change windings

    Publication Year: 1971, Page(s):537 - 542
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (656 KB)

    The paper considers the advantages which may be obtained by introducing pole-change windings into squirrel-cage induction-motor speed-control schemes employing stator-voltage variation. It is concluded that, in certain specified cases, a significant increase in the range of operation may be obtained for a given dissipation of rotor power. View full abstract»

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  • Effect of skewing slots on flux distribution in induction machines

    Publication Year: 1971, Page(s):543 - 549
    Cited by:  Papers (16)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (974 KB)

    Although skewing is practically the rule for all but the largest induction motors, its effect on the flux distribution has received little attention. It is shown by experiment that the effect of skewing can be very significant and results in a poorer performance. Some of the advantages which are commonly believed to accrue from the use of skew are fictitious if a proper choice of slot combination ... View full abstract»

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  • Novel method for reversal of single-phase squirrel-cage induction machines

    Publication Year: 1971, Page(s):550 - 554
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (554 KB)

    Several systems have been devised for the reversal of single-phase induction motors, the majority of which utilise quadrature, or approximately quadrature, stator windings. However, if the windings are constructed so that their axes are at an angle considerably less than 90° electrical, an alternative method of reversal can be obtained. Auxiliary-winding design criteria are developed for this nov... View full abstract»

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  • Rating of conductors for short-duration currents

    Publication Year: 1971, Page(s):555 - 570
    Cited by:  Papers (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1726 KB)

    The heat equation for the mean temperature of a conductor carrying a short-duration current is solved for adiabatic conditions at the surface and for all the relevant thermophysical properties varying quadratically with temperature. A simplified approximation to the solution is also given. Curves showing the variation of temperature with energy input and with the time integral of the square of the... View full abstract»

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  • Erratum: Economic comparisons in planning for electricity supply

    Publication Year: 1971
    IEEE is not the copyright holder of this material | PDF file iconPDF (119 KB)
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Aims & Scope

The Proceedings of the Institution of Electrical Engineers was published by the IET between 1963 and 1979.

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