WorldCat Identities

Royal Signals and Radar Establishment, Malvern (GB)

Overview
Works: 92 works in 97 publications in 1 language and 9 library holdings
Genres: Software 
Classifications: TA1695, 510
Publication Timeline
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Most widely held works by Royal Signals and Radar Establishment, Malvern (GB)
The Knuth-Bendix completion algorithm and its specification in Z by A Smith( Book )

1 edition published in 1989 in English and held by 3 WorldCat member libraries worldwide

Proving that something is a consequence of a set of axioms can be very difficult. The Knuth-Bendix completion algorithm attempts to automate this process when the axioms are equations. The algorithm is bound up in the area of term rewriting, and so this memorandum contains an introduction to the theory of term rewriting, followed by an overview of the algorithm. Finally a formal specification of the algorithm is given using the language Z. Great Britain. (rrh)
CO₂ laser frequency doubling using AgGaSe₂ by E. K Gorton( Book )

1 edition published in 1991 in English and held by 1 WorldCat member library worldwide

AgGaSe2 samples are examined using a CO2 laser for the frequency doubling application. The results are compared with a coupled wave equation model which includes absorption. Good agreement between the results and the model is obtained. Best energy conversion efficiency obtained under our experimental conditions was 7% with an antireflection coated 2cm long sample
Tunnelling currents in reverse biased CMT photodiodes by N. T Gordon( Book )

1 edition published in 1988 in English and held by 1 WorldCat member library worldwide

A Z specification of the MaCHO interface editor by A. W Wood( Book )

1 edition published in 1988 in English and held by 1 WorldCat member library worldwide

This document describes the basic editor part of the user interface for the SMITE secure computer architecture using the mathematical notation known as Z. Operations that are available to the user, and their effects on the screen display, are specified in conjunction with descriptions of the auxiliary functions and data structures necessary to support them. This specification will be used to implement a powerful yet trustworthy interface for the initiation and control of security related transactions. Great Britain (RH)
Monte-Carlo simulations of gas discharge systems with some applications of SF6 by P Milson( Book )

1 edition published in 1990 in English and held by 1 WorldCat member library worldwide

Assessment of the Philips USFA BV 7mm Cooling Engine by D. P Laycock( Book )

1 edition published in 1988 in English and held by 1 WorldCat member library worldwide

Philips Usfa B.V. Stirling cycle spli-mode cooling engines, sampled from development, pre-production batches, have been extensively tested at RSRE. Measurement of cryogenic performance at normal and high ambient temperatures in run-stop-run and continual-run regimes have been made. Representative detector encapsulations have been interfaced to provide typical combination heat loads. One pre-production unit has been installed and operated successfully in a Thermal Imaging Common Module (TICM) Class 2 Scanner. Detector microphony-noise measurements were made and compared with those recorded when the same array was cooled with high pressure pure gas liquified by a Hymatic self-regulating mini-cooler. Initial problems of contamination of the helium gas and of the thermal interface with the detector encapsulation have been highlighted and addressed by the manufacturers. A production standard unit has achieved over 5,000 hours intermittent and continuous running during a period of 12 months. Great Britain. (RH)
Calculation of the H-plane aperture distribution and far field pattern for a metal plate loaded horn by A Lettington( Book )

2 editions published in 1988 in English and held by 1 WorldCat member library worldwide

This note describes the results of a mathematical analysis of the aperture distribution of a horn which has been loaded with a conducting plate. The purpose of the plate is to improve the H-plane far field pattern of the horn and hence the angular resolution of a passive millimetre wave imager which uses a horn fed antenna. The calculation is based on the Fresnel-Kirchoff diffraction formula and account is taken of multiple reflections within the horn and from the plate. The resulting H-plane aperture distribution is far from uniform but has a sharp far field pattern. The E-plane distribution remains unchanged by the presence of the plate. Great Britain. (RH)
Performance of a rapid carrier acquisition circuit for satellite ground terminal modems by A. J Baynham( Book )

1 edition published in 1987 in English and held by 0 WorldCat member libraries worldwide

The performance of a Rapid Carrier Acquisition circuit for low data rate satellite communications equipment is described. The results achieved for carrier acquisition at signal to noise ratios of 30 dBHz show that acquisition can be achieved in 300 milliseconds, giving two orders of magnitude improvement over currently implemented equipment. Details of performance with various modulation schemes and operation at signal to noise ratios as low as 25 dBHz are given
Beamforming pre-processors for high discrimination algorithms by J. L Mather( Book )

1 edition published in 1989 in English and held by 0 WorldCat member libraries worldwide

High discrimination algorithms based on numerical techniques such as eigen analysis are currently being considered for use in future antenna array systems. In addition to being computationally expensive, such algorithms are only able to achieve significantly enhanced within-beam resolution at high signal to noise ratios. However, if the detected signals are found only within a limited frequency range of region of space, or if the data is oversampled, a pre-processing transform may be applied to the data. This leads to a reduction in the size of the data matrix, enables subsequent processing to be accelerated, and lowers the threshold signal to noise ratio required for within-beam resolution. In the spatial domain, the pre-processor is a beamformer. A previous memo has shown how this may be designed using singular vectors of the array calibration matrix. In the current document it is demonstrated by Monte Carlo trials that similar results may be obtained using a conventional beamformer. Great Britain
Psychophysical considerations in measuring MRTD with staring arrays by K. J Murphy( Book )

1 edition published in 1987 in English and held by 0 WorldCat member libraries worldwide

Matching ground images to map data on MIL-DAP by B. C Merrifield( Book )

1 edition published in 1988 in English and held by 0 WorldCat member libraries worldwide

Counting paths in computer programs by B. D Bramson( Book )

1 edition published in 1988 in English and held by 0 WorldCat member libraries worldwide

An algebraic method is presented for assessing the numbers of paths through loop-free portions of computer programs, thus providing a useful measure of complexity. The underlying program model is that of a directed graph, though this does not exclude recursion. The algebraic structure is that of a path algebra but with one axiom relaxed. The theory has been implemented within the Malvern Program Analysis Suite (MALPAS). Experience has shown it to be of particular value in guiding the analysis of large programs. Keywords: Radar, Computer program Verification, Semantics, Great Britain. (kr)
Multi-microprocessor control of a precision pan and tilt head by E. C. E Charlwood( Book )

1 edition published in 1989 in English and held by 0 WorldCat member libraries worldwide

This Memorandum describes further work undertaken on the microprocessor system used to control a heavy duty precision pan and tilt head previously reported in RSRE Memorandum 3996. A multiprocessor architecture was used to provide interactive control of the head and a capability to gather and track targets automatically with a thermal imager as the tracking sensor. The time taken to gather the target and establish a stable track was demonstrated to be of the order of 0.25s against a variety of aircraft targets with crossing rates up to 100mR/s. Keywords: Radar, Great Britain. (KR)
A theoretical and experimental investigation of linear and nonlinear focussing chirped optical diffraction gratings by M. F Lewis( Book )

1 edition published in 1988 in English and held by 0 WorldCat member libraries worldwide

In the past the focussing properties of chirped grating structures have been investigated in various disciplines including optics, acousto-optics and acoustics. In this paper we present the results of a detailed theoretical and experimental study of one such structure, namely the chirped optical diffraction grating, although many of the conclusions are of more general validity. We derive some useful fundamental properties of such focussing gratings, and show that to first order their behaviour is similar to that of various other classical components such as focussing lenses, grating spectrometers, and matched filters for chirped waveforms. However we also describe a fascinating range of second-order differences in behaviour, for example concerning the physical locations of the multiple foci, and the sidelobe structures within and perpendicular to the focal plane. For devices of large numerical aperture we demonstrate the advantages of using a non-linear chirp grating structure, e.g. for sidelobe suppression in the focal plane, and point out that surface acoustic wave (SAW) techniques can be used to generate the non-linear chirp waveforms necessary to implement such gratings in acousto-optic devices. Great Britain. (rh)
Software fault tolerance by L. N Simcox( Book )

1 edition published in 1988 in English and held by 0 WorldCat member libraries worldwide

The main principles of software fault tolerance are presented and various schemes for achieving it are described, with emphasis being placed on the N-version programming and the recovery blocks schemes. The areas of research discussed include reliability modeling, version independence, and system simulation. A brief description of the use of software fault tolerance in aerospace applications is given and the important subject of cost-effectiveness is addressed. The potential benefits to Air Traffic Control systems are identified together with areas where further study and research are desirable. (rh)
The integration of structured and formal methods by G. P Randell( Book )

1 edition published in 1989 in English and held by 0 WorldCat member libraries worldwide

A growing emphasis is being put on a formal, in the sense of mathematically rigorous, approach to the development of software-based systems. However, current formal 'methods' tend to be just notations. This memorandum looks at several structured methods and considers the possibilities each offers for integration with a formal notation to produce a usable formal method combining the best of both formal and structured approaches. Proposals for further work are discussed. Great Britain
Experimental measurements of scattering from simple wavelength sized phase objects by D. L Jordan( Book )

1 edition published in 1988 in English and held by 0 WorldCat member libraries worldwide

Experimental results are presented for the angular distribution of radiation scattered from single deep grooves etched in silicon. Both visible and infrared radiation is used. Whereas the grooves are wide compared to the wavelength of the visible radiation, they span a range of sizes from approximately twice down to half the infrared wavelength. Great Britain. (RH)
Language modelling for automatic speech recognition : a review by L Dodd( Book )

1 edition published in 1987 in English and held by 0 WorldCat member libraries worldwide

This memorandum reviews recent studies and developments in methods of language modelling which are specifically relevant to automatic speech recognition (ASR). An introduction is given to the general area of language models and the ways of formalising linguistic knowledge. Various techniques for applying phonological, syntactic and semantic constraints to ASR are discussed. The review covers papers written as early as the 1970's but the emphasis is on the more recent developments and techniques which are now being used in speech research. The formal methods of applying linguistic constraints are discussed and criticised according to their suitability for the speech research work carried out at RSRE
PerqFlex firmware by I. F Currie( Book )

1 edition published in 1985 in English and held by 0 WorldCat member libraries worldwide

This report describes the firmware architecture of the Flex computing system as implemented on the ICL Perq. This implementation is very similar to that described in RSRE Report 81009, (Flex Firmware by Currie, Edwards and Foster) generally referred to as the Logica implementation. This is rather a misnomer, since although Logica built the hardware (to an RSRE design) on which it was implemented, Logica had nothing to do with the micro-coding or software construction of the Flex architecture. The differences between the Perq and Logica implementation arise mainly from the properties of the underlying hardware. In the Logica Flex, for example, each byte in main-store was in fact nine bits long rather than eight; the extra bits (the tag bits) were used to distinguish between pointers and non-pointers ie between capabilities and scalar data. On Perq, however, there are no bits to spare like this. In order to distinguish between pointers and non-pointers in Perq, it was necessary to steel a bit from each 32-bit word to act as a tag bit. (Great Britain)
Hardware proofs using LCF-LSM and ELLA by W. J Cullyer( Book )

1 edition published in 1985 in English and held by 0 WorldCat member libraries worldwide

A method is described for writing the formal specifications for a digital system, a high level of design which satisfies this requirement and then a gate level realisation, using the languages LCF -LSM and ELLA. Given these formal descriptions, this papers shows how to carry out mathematical proofs to establish that the high level design respects the specification and the gate level design agrees with precisely with the high level design. By this means, a chain of correspondence proof is created from the specification to the ultimate realisation, as required during the development of safety critical and security critical hardware. There methods have been used to develop formal proofs for the VIPER microprocessor and this paper forms an essential tutorial for those studying the validation of this new 32 - bit processor. (Great Britain)
 
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English (21)