Showing papers by "Kenneth Steiglitz published in 1978"
TL;DR: It appears that local search algorithms are ineffective when applied to symmetric traveling salesman problems, because there are many local optima with arbitrarily high cost.
Abstract: We construct instances of the symmetric traveling salesman problem with n = 8k cities that have the following property: There is exactly one optimal tour with cost n, and there are 2k-1k-1! tours that are next-best, have arbitrarily large cost, and cannot be improved by changing fewer than 3k edges. Thus, there are many local optima with arbitrarily high cost. It appears that local search algorithms are ineffective when applied to these problems. Even more catastrophic examples are available in the non-symmetric case.
74 citations
TL;DR: Computational results are presented which show that N. Zadeh's pathological examples for the simplex algorithm apparently take a number of pivots approximately proportional to the number of columns in the tableau when its column order is randomized.
Abstract: Computational results are presented which show that N. Zadeh's pathological examples for the simplex algorithm apparently take a number of pivots approximately proportional to the number of columns in the tableau when its column order is randomized.
4 citations
TL;DR: This work defines classes of signals, called H-synchronous signals, which, after sampling, can be "de-aliased" with a fixed digital filter depending on H, and the McClellan-Parks-Rabiner algorithm is used to find FIR designs for such de-aliasing filters for the important special cases of piecewise-constant and piecewise
Abstract: In simulating a continuous-time system being driven by a continuous-time signal f(t), we may wish to generate a discrete-time signal whose spectrum agrees with that of f(t) for frequencies up to the Nyquist frequency One important example is provided by the simulation of the vocal tract driven by a triangularly shaped glottal pulse, although a similar problem arises whenever we simulate a known continuous-time input to a system We define classes of signals, called H-synchronous signals, which, after sampling, can be "de-aliased" with a fixed digital filter depending on H The McClellan-Parks-Rabiner algorithm is used to find FIR designs for such de-aliasing filters for the important special cases of piecewise-constant and piecewise-linear signals
4 citations
01 Apr 1978
TL;DR: An apparently new synthesis method is described, windowed synthesis, which circumvents the problem of choosing initial conditions in synthesis using a filter model, and is also applicable to cepstral vocoding.
Abstract: We describe the implementation of a practical system for pole-zero analysis-synthesis which produces synthesized speech that sounds qualitatively different from linear prediction at points of mouth closure. We also describe an apparently new synthesis method, windowed synthesis, which circumvents the problem of choosing initial conditions in synthesis using a filter model, and is also applicable to cepstral vocoding.