Showing papers by "Kenneth Steiglitz published in 1970"

Computer-aided design of recursive digital filters

Abstract: A practical method is described for designing recursive digital filters with arbitrary, prescribed magnitude characteristics. The method uses the Fletcher-Powell optimization algorithm to minimize a square-error criterion in the frequency domain. A strategy is described whereby stability and minimum-phase constraints are observed, while still using the unconstrained optimization algorithm. The cascade canonic form is used, so that the resultant filters can be realized accurately and simply. Design examples are given of low-pass, wide-band differentiator, linear discriminator, and vowel formant filters.

Optimal Design of Offshore Natural-Gas Pipeline Systems

Abstract: The exploitation of offshore natural gas reserves involves several phases, including production from reservoirs, separation of byproducts, and transportation to markets. The gas, which may originate as far as 100 miles from land, must be transported through pipelines to onshore delivery points. This paper develops techniques for solving the following problems: (1) selection of pipe diameters in a specified pipeline network to minimize the sum of investment and operation costs; (2) selection of minimum-cost network structures, given gas-field location and flow requirements; (3) optimal expansion of existing pipeline networks to include newly discovered gas fields. The techniques incorporate procedures for globally optimizing pipeline diameters for fixed tree structures and heuristic procedures for generating low-cost structures.

The design of wide-band recursive and nonrecursive digital differentiators

Abstract: Designs for recursive and nonrecursive wide-band differentiators are presented. The coefficients for the recursive differentiators were optimally chosen to minimize a square-error criterion based on the magnitude of the frequency response. The coefficients for the nonrecursive differentiators were chosen using a frequency sampling technique. One or more of the coefficients were optimally selected to minimize the peak absolute error between the obtained frequency response and the response of an ideal differentiator. The frequency response characteristics of the recursive differentiators had small magnitude errors but significant phase errors. The nonrecursive differentiators required on the order of 16 to 32 terms for the magnitude error of the frequency response to be as small as the magnitude errors for the recursive differentiators; however, there were no phase errors for the nonrecursive case. The delay of the recursive differentiators was small compared to the delay of the nonrecursive differentiators.

Input Generators for Digital Sound Synthesis

Abstract: A fast method is described for generating a periodic discrete‐time signal with harmonics of equal amplitude and a fundamental frequency which is not necessarily an integral fraction of the sampling frequency (as with ordinary pulse generators) Such a signal can be used as input to digital filters for the synthesis of speech and music

On system identification from noise-obscured input and output measurements†

Abstract: This paper deals with maximum-likelihood system identification when both the input and the output signals are corrupted by Gaussian observation noise. A derivation of exact maximum-likelihood estimation for this problem is included, but the difficulty of implementing it numerically precludes its practical evaluation at this time. A new approximate method is introduced, called the ‘output reference’ method, in which the input noise is referred to the output, and an iterative gradient search method used. This technique requires no a priori knowledge of the noise covariance matrix. The method of Koopmans—Levin, which does require knowledge of the noise covariance matrix, is then reviewed in detail, and experimental results are presented for the white noise case which indicate that the output reference method is more accurate.

A new planarity test based on 3-connectivity

Abstract: In this paper we give a new algorithm for determining if a graph is planar. The algorithm is based on Tutte's theory of 3-connected graphs, and provides a structural decomposition of the graph. Results are presented in the algorithmic form, and a computer program is described.