DOI:10.1049/piee.1964.0177

出版商:IEE    

年代:1964

数据来源: IET

DOI:10.1049/piee.1964.0178

出版商:IEE    

年代:1964

数据来源: IET

摘要:

A digital-computer formulation of the delay-line-synthesiser technique is developed, and the need for pre- and postfiltering to avoid aliasing effects is emphasised. This leads naturally to Fourier-series approximation and the least-squares error criterion. Special attention is given to numerical methods of calculating the optimum set of weights for the delay-line synthesiser, ρfactors are proposed for smoothing the approximation in the frequency domain; they appear to have a slight computational advantage, compared with the σfactors of Lanczos. A hybrid-computer method is proposed for solving the finite trigonometric-series expression for the optimum weights. The proposed method almost halves the number of arithmetic operations required by numerical analysis alone.

DOI:10.1049/piee.1964.0180

出版商:IEE    

年代:1964

数据来源: IET

摘要:

Gaseous cavities of two simple geometrical shapes are considered: (a) an elliptic cylindrical cavity with the minor axis of its elliptic cross-section parallel to the field, and (b) an oblate spheroidal cavity with its axis parallel to the field. Circular cylindrical and spherical cavities are treated as special cases.When a cavity of each of these forms is located in an infinite dielectric, which is subjected to an electric stress that is uniform at very large distances from the cavity, the electric stress in the cavity is also uniform, and the relation between the two stresses is well known. When, however, the dielectric is contained between two infinite plane parallel electrodes whose distance apart is not great compared with the dimensions of the cavity, the electric stress in the cavity is no longer uniform, and the problem does not yet appear to have been rigorously studied.In the paper, the electric stresses existing at points on the minor and major axes of the cross-section of the elliptic cylindrical cavity and on the axis and radius of the oblate spheroidal cavity have been calculated, in both alternating- and direct-voltage conditions, in terms of the stress in the solid dielectric, using a technique devised by Rayleigh for solving the Laplace equation. It is shown that the electric stress is greatest in the elliptic cylindrical cavity at the extremities of the major axis and in the oblate spheroidal cavity around its periphery. Formulas for the mean electric stress along the minor axis of the elliptic cylindrical cavity and the axis of the oblate spheroidal cavity are also derived.

DOI:10.1049/piee.1964.0182

出版商:IEE    

年代:1964

数据来源: IET

摘要:

In the preceding paper, electric stresses in elliptic cylindrical and oblate spheroidal gaseous cavities located in a dielectric contained between infinite plane parallel electrodes were calculated, using a technique devised by Rayleigh for solving the Laplace equation. The same methods give the maximum electric stresses at conducting surfaces of similar geometrical shapes located in the field between plane parallel electrodes, only very slight modifications to the equations developed previously being necessary. The formulas that have been derived in the present paper can be applied to calculate, for example, the maximum stress between successive turns of a long conducting helical coil subjected to a uniform voltage gradient and the maximum stress at the surface of the ellipsoid in an ellipsoidal voltmeter.

DOI:10.1049/piee.1964.0183

出版商:IEE    

年代:1964

数据来源: IET

摘要:

The paper describes the application of integrated production control using three computers to the Rotherham works of the Park Gate Iron and Steel Co. Ltd. The system, installed to meet the needs of a considerably expanded steelworks, will come into service early in 1964.Offline production-planning facilities cover operations from the steelmaking plant to the finishing mills, but online production co-ordination is restricted to the primary-mill area through which all products must pass. Process controls are applied as automatic programming of the bloom mill and computer control of the billet flying shear.The production-planning computer receives incoming orders and feedback data from the works. It updates the appropriate magnetic-tape files and issues working schedules to the various departments.Primary-mill instructions are issued as paper-tape input to the co-ordination computer. Here ingots are identified with orders, and processing instructions are relayed to operators on a tabular display system and by direct links to the automatic mill programmer and the shearing computer.The shear-computer system measures ingoing length, predicts outgoing length and directs billet cutting for minimum waste. It also tracks and identifies the cut billets on the cooling bank.

DOI:10.1049/piee.1964.0187

出版商:IEE    

年代:1964

数据来源: IET