Since the so-called Hopf-type amplifier has become an established element in the modeling of the mammalian hearing organ, it also gets attention in the design of nonlinear amplifiers for technical applications. Due to its pure sinusoidal response to a sinusoidal input signal, the amplifier based on the normal form of the Andronov-Hopf bifurcation is a peculiar exception of nonlinear amplifiers. This feature allows an exact mathematical formulation of the input-output characteristic and thus deeper insights of the nonlinear behavior. Aside from the Hopf-type amplifier we investigate an extension of the Hopf system with focus on ambiguities, especially the separation of solution sets, and double hysteresis behavior in the input-output characteristic. Our results are validated by a DSP implementation.

The main purpose of this paper is to reconstruct the approach to ambiguity presented in Tadeusz Pawłowski’s work Tworzenie pojęć w naukach humanistycznych („Creating concepts in the humanities”) (1986), to systematize and analyze this conception. Due to the fact that Pawłowski was a student of Tadeusz Kotarbiński and Janina Kotarbińska, and that he dealt with methodological issues concerning the language of science (and scientific philosophy), the background of my considerations is the tradition of the Lvov‑Warsaw School. In the article I also formulate some remarks on Pawłowski’s conception, as well as some other observations on ambiguity.

The aim of this article is to present the fantastic literature of J.-P. Bours, one of the least known representatives of the Belgian uncanny. His oeuvre is remarkably rich: Bours practices all the sub-genres of the fantastic and remains a master of the short form. In this article, I analyze the distinct characteristic of this fantastic literature: ambiguity. In order to produce this effect, the writer uses a vast array of techniques (like the unsaid and ellipsis), as shown in La Mort du juste.

The article considers information technology for the realization of human communication using residual human capabilities, obtained by organizing text entry using mobile and auxiliary devices. The components of the proposed technology are described in detail: the method for entering text information to realize the possibility of introducing a limited number of controls and the method of predicting words that are most often encountered after words already entered in the sentence. A generalized representation of the process of entering text is described with the aid of an ambiguous virtual keyboard and the representation of control signals for the selection of control elements. The approaches to finding the optimal distribution of the set of alphabet characters for different numbers of control signals are given. The method of word prediction is generalized and improved, the statistical language model with "back-off" is used, and the approach to the formation of the training corpus of the spoken Ukrainian language is proposed.