NASA Scientific and Technical Aerospace Reports

20060002115 Iowa Univ., Iowa City, IA, USA
Design and Implementation of Velocity Filters Using Multichannel Array Processing Techniques
Hanna, Magdy T.; Simaan, M.; 1987 IEEE International Symposium on Circuits and Systems, Volume 2; 1987, pp. 641-644;
In English; See also 20060002103; Copyright; Avail.: Other Sources
A general procedure for designing two-dimensional (2D) velocity filters based on array filters derived originally for
multichannel (multiple input single output) processing of the recordings of an array of sensors is presented. These filters can
be implemented in the frequency domain using the 2D Fast Fourier Transform. A specific case of velocity filters based on a
family of multichannel array filters obtained recently for attenuating a coherent interference in the array recordings is worked
out in detail.
Author
Fourier Transformation; Attenuation; Frequencies; Multichannel Communication
20060002116 Saitama Univ., Urawa, Japan
An Approach for Analysis of Chaos in Josephson Autonomous Circuit
Morisue, Mititada; Kasahara, Hideki; Araki, Kiyomichi; 1987 IEEE International Symposium on Circuits and Systems,
Volume 2; 1987, pp. 664-667; In English; See also 20060002103; Copyright; Avail.: Other Sources
A novel approach for analysis of chaos and its associated oscillations produced in Josephson autonomous circuit is
proposed. In the approach the period of free-running periodic oscillations is first determined by computer assisted technique,
and then the solutions for oscillations are plotted in a 3-dimensional plane and in a Poincare section. By using this approach,
what types of oscillations in Josephson autonomous circuit are produced is discussed.
Author
Autonomy; Chaos; Circuits
20060002117 Columbia Univ., New York, NY, USA
Timing-Controlled Switched Analog Filters with Full Digital Programmability
Vallancourt, David; Tsividis, Yannis; 1987 IEEE International Symposium on Circuits and Systems, Volume 2; 1987,
pp. 329-333; In English; See also 20060002103
Contract(s)/Grant(s): ECS-83-10227; Copyright; Avail.: Other Sources
Analog Signa1 Processors (ASPs) offering separate digital programming of each transfer function coefficient are
demonstrated. In these ASPs, each network branch gain is determined by a single digitally-controlled analog transmission gate,
and no selectable capacitor (or resistor) arrays arc required. Some of the ASPs described exhibit programmable topology,
simultaneous multiple-signal, multiple-transfer function capability, and/or freedom from reliance on any capacitor or resistor
ratios. Processors operating on continuous signals as well as those operating on sampled signals are discussed; the latter have
been integrated in 4/micron CMOS technology.
Author
Signal Processing; Digital Systems; Capacitors; Transfer Functions; Switching
20060002119 Stanford Univ., CA, USA
The Original Adaptive Neural Net Broom-Balancer
Widrow, Bernard; 1987 IEEE International Symposium on Circuits and Systems, Volume 2; 1987, pp. 351-357; In English;
See also 20060002103; Copyright; Avail.: Other Sources
This paper reviews work on artificial adaptive neurons done at Stanford University almost 25 years ago. The development
of an adaptive linear threshold element (ADALINE) and several of of its mathematical properties are described. Applications
were made to pattern recognition, speech recognition, classification of EKG waveforms, weather forecasting, and to control
systems. An ADALINE element, a single artificial neuron, was used as a trainable controller to stabilize an inverted pendulum.
This was the original adaptive broom-balancer. The broom-balancer of the future will be a system that can learn to balance
the ‘broom’ by observing the real time control decisions made by the teacher, an expert who knows how to do the control
function. The teacher has access to the critical control state variables. The trainable system, an ADALINE network, observes
the cart and pendulum through visual (photocell array or TV) inputs and must of its own accord obtain the relevant state
information by dynamic scene analysis. With an adequate training sample, the ADALINE net wi11 be able to take over the
control function from the teacher and thus become a trained expert. This research will lead to a new class of trainable expert
systems.
Author
Neurons; Access Control; Controllers; Pattern Recognition; Neural Nets; Information Analysis; Expert Systems
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