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Optimizing the signal-to-noise ratio in a television camera preamplifier. An exercise in c.a.d.
Comput. Struct., Vol 2 (1972), pp 3 1 - 4 5 . The author briefly describes shell t h e o r y and equations and then surveys the t y p e s o f shell problem that are i m p o r t a n t to the structural designer. He outlines the main approaches to the shell problem and then deals with the i m p o r t a n t effect of the c o m p u t e r on shell analysis. The paper covers stress and deflection analysis, buckling, vibration a n d the transient response: also, the m e t h o d s of shell analysis include both the analytical and the numerical. The principal impact of the c o m p u t e r is a n e w ability to obtain solutions for very general shell configurations. while incorporating structural details that occur in practical design. Ungurearu, N and lonescu, I. 'A numerical m e t h o d for designing beams and slabs supported on an elastic, homogeneous isotropic m e d i u m . ' Bull. Inst. Politeb lasi, Vol 17, No 21 (1971) No 3--4 pp 25--32 (in French).
Van Oosurom, J. a n d Sherbourne, A. N. 'Plastic analysis of castellated beams. 1 - Interaction of m o m e n t , shear and axial force. 2 - Analysis and tests'. Comput. Struct., Vol 2 (1972), pp 1 1 1 - 1 4 0 . The paper reviews the stress-resultant and non-local theories of shear and m o m e n t interaction at fully plastic sections. Lowerb o u n d relationships are derived for shear, m o m e n t and axial-force interaction of plastic, rectangular and T sections. In Part 2, the results are used to develop an incremental c o m p u t e r procedure for analysing castellated beams in the elastic and plastic domains. The analysis treats the beam as a Vihrendell truss chord, and vertical elem e n t s obey m o m e n t , shear and axial force relationships developed earlier. Initially, the elastic analysis idealizes the beam as being c o m p o s e d of discrete elements and determines the behaviour using a flexibility app roach.
A system called DESIGN PAD consists of a small computer-graphic display connected to a time-sharing computer. The system accepts problems - in a wide variety of applications - in the form of labelled block diagrams. The article discusses input and output, m a n / m a c h i n e interface and data structure. Baugh, C R. and Outndersakaran, C S. 'Optimal networks o f N O R - O R gates for functions of three variables.' Inst. Elect. Electron. Eng. Trans. Comput., Vol G21 (2rid February 1972) pp 1 5 3 - 1 6 0 . Lotte, K. M., Smethurst, B., and Thompson, K. Computer-aided design - t h e need for sophisticated data handling'. Proc. Inst. Cir. Eng., Vol 51 (January 1972), p.107. The authors outline the conclusions of a particular s t u d y o f c o m p u t e r s in engineering design, particularly civil engineering design. Storing information and passing it from one application or analysis to the n e x t is an important part of the civil engineer's work. The authors consider h o w to develop effective s y s t e m s to allow engineers to make use of computers. Suitable software and cheap reliable terminals, to which STD lines a n d m o d e m s are the short-term equivalents, could lead to a 5% reduction in the material c o n t e n t of m a n u f a c t u r e d goods. Savings of this order are now being quoted for advanced use of computers. Desmarais, R. N. and Bennett, R. M. ' C o m p u t e r programs for plotting curves with various dashed-line sequences.' National
Aeronautics and Space Administration, Wasbington DC, U.S.A.
Electrical and electronics engineering Abbas, G. and Nichols, K.
Electron. Lett., Vol 8, No 7 (6th April Sawko, F. 'A note on the c o m p u t e r analysis of foundation rafts resting on plastic soils'. Struct. Eng., Vol 50, No 4 (April 1972). The author puts forward an alternative m e t h o d of analysing the foundations of a concrete raft; his m e t h o d assumes an elastic sub-grade c o m p o s e d of very soft springs which give prominence to raft stiffness and ensure u n i f o r m distribution of upthrust. The m e t h o d automatically satisfies both the local and the overall equilibrium. The paper analyses two approaches to a raft which the author made for the consulting engineers in a practical case. The predictions of the two m e t h o d s are compared. The new m e t h o d can be used in conjunction with the present c o m p u t e r programs capable of analysing grillages resting on an elastic foundation. No new programming or development is required.
Computing Blasgen, M. W., Evangelisti, C. J. a n d Tennison, R. D. 'A c o m p u t e r graphics system for block diagram problems'. IBM Syst. J., Vol 10 (1971), No 2, p 143.
Volume 4 N u m b e r 5 October 1972
1972) p 170. The letter describes an algorithm for tolerancing of c o m p o n e n t s in a c o m p a c t nonlinear transient-analysis program. A finitedifference representation of the network differential equations in nodal-admittancematrix form is employed. An appreciable saving in c o m p u t e r time is m a d e by the algorithm not needing to re-tun the whole program for each set of c o m p o n e n t values. Atkinson, M. P. a n d Lang, S. R. Technical applications: a comparison of some inverse Laplace transform techniques for use in circuit design.' Comput. J., Vol 15, No 2, pp 1 3 8 - 1 3 9 . The paper describes a search for a m e t h o d of reliably obtaining the time response of a circuit when the frequency response is available.
¢~uang, S. C and Slapak, C. T. 'Program package for linear-system order reduction.' Electron. Lett., Vol 8, No 7, (6th April 1972) pp.172--173. This letter describes a package for order reduction of linear systems that can be described by a scalar transfer function. The program uses Chen's m e t h o d , which is based on a type of continued-fraction expansion. The package, called LIMOSI,
consists of four programs and calculates a second-order model of a system transfer function.
Hills, M. T., Constantine, H. and Chung, P. 'Telecommunications oriented programming language for switching systems'. Proc. Inst. Elect. Eng., Vol 119, No 4 (April 1972), pp 4 0 9 - 4 1 5 . The paper describes TPL1, a telecommunication-oriented programming language which has been i m p l e m e n t e d to show t h e kind of language which the a u t h o r s t h i n k desirable. The language is high level, real time and has been used for telephone exchanges and similar applications. It contains run-time subroutines as separate entities for performing linked-list processing; NEW R E C O R D is one example. These concepts do provide some restrictions and make some assumptions in the programming. Nevertheless the authors suggest that the gain from a debugged and real-time data handling subroutines far outweighs the need for complete flexibility. Kjelkerud, E. A c o m p u t e r program for the synthesis of switching circuits by decomposition. Inst.
Elect. Electron. Eng. Trang Comput., Vol C-21, No.6 (June 1972) p p . 5 6 8 - 5 7 3 . The paper describes a c o m p u t e r program for the synthesis of single-output combinational switching circuits. The program input requirements are up to ten variables for t h e Boolean expression and a functionally complete set of switching functions. The program uses a new proof for a generalized version o f a t h e o r e m first stated by A s h e n h u r s t a n d the paper shows the usefulness of implementing a modified form of the decomposition chart technique. Marquerlnck, J. K. 'Optimizing t h e signal-to-noise ratio in a television camera preamplifier. An exercise in c.a.d.' Pbilips Electron. Applic. Bull., Vol 31, No 2 (1972) pp 7 4 - 1 3 2 .
Port~rman, J. G. and Hogg, B. W. ' C o m p u t e r m e t h o d s for design of electricitysupply networks'. Proc. Inst. Elect. Eng., Vol 119, No 7 (July 1972), pp 8 5 1 - 8 5 6 . The paper presents a mathematical model derived from t h e engineering of a supply network operating at a single voltage and neglecting losses. From this, t h e authors have constructed an interactive design system whose unusual feature is that it allows the c o m p u t e r to contribute as a simulated designer. Several different outline designs are available and can be examined for load flows: the final design is analysed by formal statistical sampling o f substation groups. The s y s t e m is likely to suit networks operating at 35 kV to 275 kV a n d with 40 or more substations, in a reasonable c o m p u t : ing time. The different solutions developed from different original designs closely resemble one another, which suggests that they are near the o p t i m u m . Vandorp, D. and Borel, J. et al 'An accurate two-dimensional run-analysis of the MOS transistor.' Solid St Electron, Vol 15, No 5 (May 1972) pp.547--557. V'mter, IL B. and Fallside, F. 'Generalized and Neustadt algorithm for m i n i m u m time control of linear system with
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Van Oosurom, J. a n d Sherbourne, A. N. 'Plastic analysis of castellated beams. 1 - Interaction of m o m e n t , shear and axial force. 2 - Analysis and tests'. Comput. Struct., Vol 2 (1972), pp 1 1 1 - 1 4 0 . The paper reviews the stress-resultant and non-local theories of shear and m o m e n t interaction at fully plastic sections. Lowerb o u n d relationships are derived for shear, m o m e n t and axial-force interaction of plastic, rectangular and T sections. In Part 2, the results are used to develop an incremental c o m p u t e r procedure for analysing castellated beams in the elastic and plastic domains. The analysis treats the beam as a Vihrendell truss chord, and vertical elem e n t s obey m o m e n t , shear and axial force relationships developed earlier. Initially, the elastic analysis idealizes the beam as being c o m p o s e d of discrete elements and determines the behaviour using a flexibility app roach.
A system called DESIGN PAD consists of a small computer-graphic display connected to a time-sharing computer. The system accepts problems - in a wide variety of applications - in the form of labelled block diagrams. The article discusses input and output, m a n / m a c h i n e interface and data structure. Baugh, C R. and Outndersakaran, C S. 'Optimal networks o f N O R - O R gates for functions of three variables.' Inst. Elect. Electron. Eng. Trans. Comput., Vol G21 (2rid February 1972) pp 1 5 3 - 1 6 0 . Lotte, K. M., Smethurst, B., and Thompson, K. Computer-aided design - t h e need for sophisticated data handling'. Proc. Inst. Cir. Eng., Vol 51 (January 1972), p.107. The authors outline the conclusions of a particular s t u d y o f c o m p u t e r s in engineering design, particularly civil engineering design. Storing information and passing it from one application or analysis to the n e x t is an important part of the civil engineer's work. The authors consider h o w to develop effective s y s t e m s to allow engineers to make use of computers. Suitable software and cheap reliable terminals, to which STD lines a n d m o d e m s are the short-term equivalents, could lead to a 5% reduction in the material c o n t e n t of m a n u f a c t u r e d goods. Savings of this order are now being quoted for advanced use of computers. Desmarais, R. N. and Bennett, R. M. ' C o m p u t e r programs for plotting curves with various dashed-line sequences.' National
Aeronautics and Space Administration, Wasbington DC, U.S.A.
Electrical and electronics engineering Abbas, G. and Nichols, K.
Electron. Lett., Vol 8, No 7 (6th April Sawko, F. 'A note on the c o m p u t e r analysis of foundation rafts resting on plastic soils'. Struct. Eng., Vol 50, No 4 (April 1972). The author puts forward an alternative m e t h o d of analysing the foundations of a concrete raft; his m e t h o d assumes an elastic sub-grade c o m p o s e d of very soft springs which give prominence to raft stiffness and ensure u n i f o r m distribution of upthrust. The m e t h o d automatically satisfies both the local and the overall equilibrium. The paper analyses two approaches to a raft which the author made for the consulting engineers in a practical case. The predictions of the two m e t h o d s are compared. The new m e t h o d can be used in conjunction with the present c o m p u t e r programs capable of analysing grillages resting on an elastic foundation. No new programming or development is required.
Computing Blasgen, M. W., Evangelisti, C. J. a n d Tennison, R. D. 'A c o m p u t e r graphics system for block diagram problems'. IBM Syst. J., Vol 10 (1971), No 2, p 143.
Volume 4 N u m b e r 5 October 1972
1972) p 170. The letter describes an algorithm for tolerancing of c o m p o n e n t s in a c o m p a c t nonlinear transient-analysis program. A finitedifference representation of the network differential equations in nodal-admittancematrix form is employed. An appreciable saving in c o m p u t e r time is m a d e by the algorithm not needing to re-tun the whole program for each set of c o m p o n e n t values. Atkinson, M. P. a n d Lang, S. R. Technical applications: a comparison of some inverse Laplace transform techniques for use in circuit design.' Comput. J., Vol 15, No 2, pp 1 3 8 - 1 3 9 . The paper describes a search for a m e t h o d of reliably obtaining the time response of a circuit when the frequency response is available.
¢~uang, S. C and Slapak, C. T. 'Program package for linear-system order reduction.' Electron. Lett., Vol 8, No 7, (6th April 1972) pp.172--173. This letter describes a package for order reduction of linear systems that can be described by a scalar transfer function. The program uses Chen's m e t h o d , which is based on a type of continued-fraction expansion. The package, called LIMOSI,
consists of four programs and calculates a second-order model of a system transfer function.
Hills, M. T., Constantine, H. and Chung, P. 'Telecommunications oriented programming language for switching systems'. Proc. Inst. Elect. Eng., Vol 119, No 4 (April 1972), pp 4 0 9 - 4 1 5 . The paper describes TPL1, a telecommunication-oriented programming language which has been i m p l e m e n t e d to show t h e kind of language which the a u t h o r s t h i n k desirable. The language is high level, real time and has been used for telephone exchanges and similar applications. It contains run-time subroutines as separate entities for performing linked-list processing; NEW R E C O R D is one example. These concepts do provide some restrictions and make some assumptions in the programming. Nevertheless the authors suggest that the gain from a debugged and real-time data handling subroutines far outweighs the need for complete flexibility. Kjelkerud, E. A c o m p u t e r program for the synthesis of switching circuits by decomposition. Inst.
Elect. Electron. Eng. Trang Comput., Vol C-21, No.6 (June 1972) p p . 5 6 8 - 5 7 3 . The paper describes a c o m p u t e r program for the synthesis of single-output combinational switching circuits. The program input requirements are up to ten variables for t h e Boolean expression and a functionally complete set of switching functions. The program uses a new proof for a generalized version o f a t h e o r e m first stated by A s h e n h u r s t a n d the paper shows the usefulness of implementing a modified form of the decomposition chart technique. Marquerlnck, J. K. 'Optimizing t h e signal-to-noise ratio in a television camera preamplifier. An exercise in c.a.d.' Pbilips Electron. Applic. Bull., Vol 31, No 2 (1972) pp 7 4 - 1 3 2 .
Port~rman, J. G. and Hogg, B. W. ' C o m p u t e r m e t h o d s for design of electricitysupply networks'. Proc. Inst. Elect. Eng., Vol 119, No 7 (July 1972), pp 8 5 1 - 8 5 6 . The paper presents a mathematical model derived from t h e engineering of a supply network operating at a single voltage and neglecting losses. From this, t h e authors have constructed an interactive design system whose unusual feature is that it allows the c o m p u t e r to contribute as a simulated designer. Several different outline designs are available and can be examined for load flows: the final design is analysed by formal statistical sampling o f substation groups. The s y s t e m is likely to suit networks operating at 35 kV to 275 kV a n d with 40 or more substations, in a reasonable c o m p u t : ing time. The different solutions developed from different original designs closely resemble one another, which suggests that they are near the o p t i m u m . Vandorp, D. and Borel, J. et al 'An accurate two-dimensional run-analysis of the MOS transistor.' Solid St Electron, Vol 15, No 5 (May 1972) pp.547--557. V'mter, IL B. and Fallside, F. 'Generalized and Neustadt algorithm for m i n i m u m time control of linear system with
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