摘要:

The paper describes a system for capturing and compressing video data in real time. It has principally been used for recording activity on the screen of computer workstations. Its main application has been in evaluating the useability of computer based products from a human factors point of view, as it allows the replay of screen displays with the same high fidelity as the original computer system. The displays are captured in digital form, and owing to the capacity and speed of digital storage media, it is necessary to apply significant data compression during the recording phase. The paper examines the degree of data compression necessary to be able to handle typical computer workstations. Some of the known techniques of data reduction are outlined, and a practical data compression system described.

DOI:10.1049/ip-e.1990.0041

出版商:IEE    

年代:1990

数据来源: IET

摘要:

In the paper the author develops a unified bidirectional linear systolic array for performing model reduction of a feedback control system using continued fractions. The array is capable of computing the 1st, 2nd and 3rd Cauer forms of the fraction and their associated inverses as well as the Routh stability criterion. Timing graphs are presented to indicate the speed-up obtained on five transputers for common problem ranges.

DOI:10.1049/ip-e.1990.0042

出版商:IEE    

年代:1990

数据来源: IET

摘要:

A spectral approach to the synthesis of a tributary switching network (TRIB), that is the irredundant Maitra cascade, is presented. The properties of Boolean functions which are TRIB-realisable are defined in the Rademacher-Walsh spectral domain. An algorithm for realising a TRIB based on these properties is given. The procedure is quite efficient for hand computation and computer operation. The method is demonstrated by numerical examples.

DOI:10.1049/ip-e.1990.0043

出版商:IEE    

年代:1990

数据来源: IET

摘要:

An intelligent sensor home automation network based on TMS7000 family of single-chip microcomputers is presented. This network could be applied to energy management, security or control of domestic equipment in individual houses. The intelligent sensors are connected to a central station by means of central heating pipes which play the role of energy supply and information transmission lines, hence offering the advantage of eliminating the expensive operation of installing specific conductors and the physical realisation of interconnections. The central station and the intelligent sensors are described and we show that the use of microcomputers permits the reduction of system complexity and the energy consumption. Finally, the experiments realised in a real site are presented.

DOI:10.1049/ip-e.1990.0044

出版商:IEE    

年代:1990

数据来源: IET

摘要:

The paper presents a new method for computing all 2ncanonical Reed-Muller forms (RMC forms) of a Boolean function. The method constructs the coefficients directly and no matrix-multiplication is needed. It is also usable for incompletely specified functions and for calculating a single RMC form. The method exhibits a high degree of parallelism.

DOI:10.1049/ip-e.1990.0045

出版商:IEE    

年代:1990

数据来源: IET

摘要:

An intelligent natural language interface to a signal processing system is described. Users type commands to the interface in a form of english orientated towards mathematical operations. The interface will interpret them, and if the commands are known to the interface, it will execute them. If any commands are unknown to the interface, a dialogue will be initialised whereby the system will seek clarification of the unknown ones. Such commands may be re-expressed either in terms of previously encountered synonymous commands, or as functions of simpler commands. The newly defined command is saved for future use. Nonprogrammers are thus able to define ‘programs’ and tailor the signal processing system for their own purposes. Although natural language interfaces are not new, this system is novel in its learning capabilities.

DOI:10.1049/ip-e.1990.0046

出版商:IEE    

年代:1990

数据来源: IET

摘要:

The representation of quaternary switching functions by means of Reed-Muller algebraic expansions described over the Galois field GF(4) is discussed. An evaluation of the cost, in terms of basic field operations, is given for performing the fundamental transforms and for searching for the optimum fixed polarity expansion. The existence of a very large number of consistent mixed polarity canonical forms is demonstrated and their basis vectors are listed.

DOI:10.1049/ip-e.1990.0047

出版商:IEE    

年代:1990

数据来源: IET

摘要:

The paper applies the information theoretic approach we have developed for the construction of efficient decision trees to the two-level switching function minimisation problem.

DOI:10.1049/ip-e.1990.0048

出版商:IEE    

年代:1990

数据来源: IET

摘要:

A scheme for maintaining a balanced search tree on a distributed memory parallel architecture is described. A general 2P−2– 2P(for integerP≥ 3) search tree is introduced with a linear array of up to [log2N/(P−2)] + 1 processors being used to implement such a search tree. As many as ([log2N/(P−2)] + 1)/2 operations can execute concurrently. Insertion and deletion transformations are described and several search trees are demonstrated on an array of transputer processors. Variations in both the number of processors allocated to the array and the value ofPallow the optimal search structure for a given architecture to be determined.

DOI:10.1049/ip-e.1990.0049

出版商:IEE    

年代:1990

数据来源: IET

摘要:

Fibre distributed data interface (FDDI) is a local-area network that supports data transmission at 100 Mbit/s using token passing. It supports synchronous and asynchronous data transmissions and allows each station to have multiple classes of asynchronous data. The performance of a homogeneous FDDI network is considered for multiple classes of traffic. The model presented can be used to evaluate the throughput of FDDI networks for different priority threshold values. The model can also be used to determine the control parameters of the priority scheme to meet the throughput requirements of different classes of traffic. The throughput characteristics derived using the above model are verified using computer simulations. Performance characteristics of FDDI networks, obtained via simulations, are also presented.

DOI:10.1049/ip-e.1990.0050

出版商:IEE    

年代:1990

数据来源: IET