Use Of Multipliers Research Articles

Quantum-barrier-varactor diodes for high-efficiency millimetre-wave multipliers

A new device, the quantum-barrier-varactor diode (QBV diode), is proposed for use in multipliers for millimetre waves. Since the capacitance/voltage characteristic is symmetric, only odd harmonics are obtained. Hence there is no idler circuit to consider for the tripler and only one for the quintupler. It is shown that for triplers and quintuplers, the theoretical efficiency using QBVs is comparable or possibly larger than using Schottky varactor diodes.

High-speed architectures for digital image processing

This paper introduces the problem of and presents some state-of-the-art approaches for high-speed digital image processing. An architecture based on distributed arithmetic, which eliminates the use of multipliers, is described. A minimum-cycle-time filter architecture, which features a high degree of parallelism and pipelining, is shown to have a throughput rate that is independent of the filter order. Furthermore, a new multiprocessing-element architecture is proposed. This leads to a filter structure which can be implemented using identical building blocks. A modular VLSI architecture based on the decomposition of the kernel matrix of a two-dimensional (2-D) transfer function is also presented. In this approach, a general 2-D transfer function is expanded in terms of low-order 2-D polynomials. Each one of these 2-D polynomials is then implemented by a VLSI chip using a bit-sliced technique. In addition, a class of nonlinear 2-D filters based on the extension of one-dimensional (1-D) quadratic digital filters is introduced. It is shown that with the use of matrix decomposition, these 2-D quadratic filters can be implemented using linear filters with some extra operations. Finally, comparisons are made among the different approaches in terms of cycle time, latency, hardware complexity, and modularity.

Langage naturel et expertise psychiatrique. Les marques de quantité dans la description des sujets expertisés : précision ou exactitude ?

One of the most important pitfalls of the activity of an expert is that he has to communicate a technical knowledge in a natural language. Compared with the technical, the natural language comprises several ambiguous informations. The aim of the present study, focussed on the use of multipliers, was to assess the degree of vagueness in the descriptions of personality made by experts in forensic psychiatry. A systematic analysis of the combinations multipliers adjectives used in descriptions of delinquents and murderers' personality leds to the increase in the exactness of the descriptive statements but rather was used for pejorative emphasis. These results were discussed in terms of the expectancies of the court room in relation to the experts.

Off-axis multivariable circle stability criterion

In 1968, the scalar circle stability criterion was extended by Cho and Narendra to the off-axis case by the use of multipliers Q, Q−1 which have an RL or RC realise structure, so that the product of the linear portion of the feedback system and the multiplier was positive-real. Fabl, Freedman and Zames produced a multivariable on-axis circle criterion for systems whose linear part is normal for all frequencies. As yet the off-axis circle criterion has not yet been established for the multivariable case, although Cook (1976) has shown that a criterion of this type does provide the conditions for the absence of limit cycles. Utilising the loop transformation theorem and the passivity theorem, an off-axis multivariable circle stability criterion is established via the method of multipliers for nonlinear feedback systems with a normal linear operator. The criterion is shown to have a simple graphical interpretation based on the Nyquist plots of the eigenvalues of the system.

Generalized Lagrange Multipliers in Integer Programming

This paper combines the theory of generalized Lagrange multipliers with a reformulation of the integer-programming problem due to group theory. The use of multipliers enhances the algorithmic efficiency of group theory in a variety of ways. One particular application is the approximation of generalized Lagrange multipliers by generalized linear programming as suggested by Brooks and Geoffrion. This procedure is shown to be closely related to the cutting-plane method of Gomory.