Characteristics of Typewriter Noise

IBM Typewriter Innovation

The evolution of the writing machine from early eighteenth-century concepts to the modern electronic typewriter represents a rich history of innovative efforts by many individuals in several countries. This paper briefly highlights several significant early milestones and then draws particular attention to typewriter developments within the IBM Corporation. After entering the typewriter busines...

Slips of the typewriter key

This article presents an analysis of 500 submorphemic slips of the typewriter key that escaped the notice of authors and other proofreaders and thereby made their way into the published records of scientific research. Despite this high selectivity, the corpus is not found to differ in major ways from other collections of keying slips. The main characteristics of this error type include a predom...

Bounds on the reliability of typewriter channels

New lower and upper bounds on the reliability function of typewriter channels are given. Our lower bounds improve upon the (multiletter) expurgated bound of Gallager, furnishing a new and simple counterexample to a conjecture made in 1967 by Shannon, Gallager and Berlekamp on its tightness. The only other known counterexample is due to Katsman, Tsfasman and Vlăduţ who used algebraic-geometric c...

Noise characteristics of surface electrodes

Spectral characteristics of pitot noise

For experimental studies of transition from laminar to turbulent boundary layer flow it is important to know the ambient noise spectrum in the facility. In supersonic wind tunnels this is often assessed by measuring pitot pressure noise. A discussion of such measurements is given, e. g., by Salyer et al. [1], see also Parziale et al. [2]. The question arises as to whether the noise measured by ...