412 research outputs found
Spectral and temporal gating mechanisms enhance the clutter rejection in the echolocating bat, Rhinolophus rouxi
Doppler shift compensation behaviour in horseshoe bats, Rhinolophus rouxi, was used to test the interference of pure tones and narrow band noise with compensation performance. The distortions in Doppler shift compensation to sinusoidally frequency shifted echoes (modulation frequency: 0.1 Hz, maximum frequency shift: 3 kHz) consisted of a reduced compensation amplitude and/or a shift of the emitted frequency to lower frequencies (Fig. 1).
Pure tones at frequencies between 200 and 900 Hz above the bat's resting frequency (RF) disturbed the Doppler shift compensation, with a maximum of intererence between 400 and 550 Hz (Fig. 2). Minimum duration of pure tones for interference was 20 ms and durations above 40 ms were most effective (Fig. 3). Interfering pure tones arriving later than about 10 ms after the onset of the echolocation call showed markedly reduced interference (Fig. 4). Doppler shift compensation was affected by pure tones at the optimum interfering frequency with sound pressure levels down to –48 dB rel the intensity level of the emitted call (Figs. 5, 6).
Narrow bandwidth noise (bandwidth from ± 100 Hz to ± 800 Hz) disturbed Doppler shift compensation at carrier frequencies between –250 Hz below and 800 Hz above RF with a maximum of interference between 250 and 500 Hz above resting frequency (Fig. 7). The duration and delay of the noise had similar influences on interference with Doppler shift compensation as did pure tones (Figs. 8, 9). Intensity dependence for noise interference was more variable than for pure tones (-32 dB to -45 dB rel emitted sound pressure level, Fig. 10).
The temporal and spectral gating in Doppler shift compensation behaviour is discussed as an effective mechanism for clutter rejection by improving the processing of frequency and amplitude transients in the echoes of horseshoe bats
The Language of Negotiation in Management Training
In this paper teaching Negotiation in a foreign language is seen as teaching 'the language of Negotiation' rather than teaching Negotiation techniques. One teaching project in a Norwegian firm is described. Method and content in the course are based on research using Negotiation data and on an 'on-line' needs analysis. Two teaching units are focused on: questions and 'meta-labels'
Measuring Progress in Discourse Production. A genre-based approach
The aim of this paper is to find criteria for the evaluation of oral business discourse produced in the language laboratory by students of business German. I felt the lack of an instrument that measures more precisely, not only linguistic criteria like lexis and grammar, but also the pragmatic background and the functions that discourse types within ‘language for specific purposes’ (LSP) have to fulfil. By evaluation I mean the asses-sment of individual progress, but indirectly I evaluate a teaching concept. A good teaching programme should facilitate progress.I am going to describe a teaching concept called Übertragung ‘text transfer’, focusing on the project that provided the data material for the present study. I will then present the model I have chosen as a basis for the study. In the study itself I concentrate on ‘text organisation’ and ‘content structure’
Translating inheritance nets to default logic
We give a translation of inheritance nets to normal default
theories. To avoid discussions about sceptical and credulous
reasoning we only regard unambiguous nets but allow explicit
exception links restricting the validity of direct links.
Contrary to former translations every link will be translated
to a "hard" fact of the corresponding default theory while the
defaults only repesent the implicit assumptions made when
computing the extension of the net. The translation is sound and
complete if we restrict the deduction mechanism of default logic
appropriately
Spin Seebeck and Spin Nernst Effects of Magnons in Noncollinear Antiferromagnetic Insulators
Our joint theoretical and computer experimental study of heat-to-spin
conversion reveals that noncollinear antiferromagnetic insulators are promising
materials for generating magnon spin currents upon application of a temperature
gradient: they exhibit spin Seebeck and spin Nernst effects. Using Kubo theory
and spin dynamics simulations, we explicitly evaluate these effects in a single
kagome sheet of potassium iron jarosite, KFe(OH)(SO), and
predict a spin Seebeck conversion factor of at a
temperature of .Comment: 6 pages, 3 figure
Zur Bewertung von Niederdeutsch und lokalem Substandard in Hamburg
Based on the results of a quantitative study it is to be shown how Low German and forms of the Substandard of Hamburg are estimated within the population. The study was conducted within the context of the project Einstellungen gegenüber regionalen Sprachformen in der Großstadt: Niederdeutsch in Hamburg (NiH) (Attitudes towards regional languages in the city: Low German in Hamburg). The article takes a closer look at the connection between evaluation and social parameters such as age, language skills, origin and education. Finally, the potential differences in the evaluation between Low German and the vernacular Hamburg speech will be examined
The semantics of rational contractions
This paper is concerned with the revision of beliefs in the face
of new and possibly contradicting information. In the Logic of
Theory Change developed by Alchourron, Gärdenfors and Makinson
this nonmonotonic process consists of a contraction and an
expansion of a set of formulas. to achieve minimal change they
formulated widely accepted postulates that rational contractions
have to fulfill.
Contractions as defined by Alchourron, Gärdenfors and Makinson
only operate on deductively closed sets of Formulas. Therefore
they cannot be used in practical applications, eg. knowledge
representation, where only finitely representable sets can be
handled.
We present a semantical characterization of rational finite
contractions (the class of rational contractions maintaining
finite representability) which provides an insight into the true
nature of these operations. This characterization shows all
possibilities to define concrete functions possessing these
properties.
When regarding concrete contractions known from literature in the
light of our characterization we have found that they are all
defined according to the same semantical strategy of minimal
semantical change. As this strategy does not correspond to the
goal of keeping as many important fotmulas as possible in the
contracted set, we suggest a finite contraction defined according
to the new strategy of maximal maintenance
Spectral and temporal gating mechanisms enhance the clutter rejection in the echolocating bat, Rhinolophus rouxi
Doppler shift compensation behaviour in horseshoe bats, Rhinolophus rouxi, was used to test the interference of pure tones and narrow band noise with compensation performance. The distortions in Doppler shift compensation to sinusoidally frequency shifted echoes (modulation frequency: 0.1 Hz, maximum frequency shift: 3 kHz) consisted of a reduced compensation amplitude and/or a shift of the emitted frequency to lower frequencies (Fig. 1).
Pure tones at frequencies between 200 and 900 Hz above the bat's resting frequency (RF) disturbed the Doppler shift compensation, with a maximum of intererence between 400 and 550 Hz (Fig. 2). Minimum duration of pure tones for interference was 20 ms and durations above 40 ms were most effective (Fig. 3). Interfering pure tones arriving later than about 10 ms after the onset of the echolocation call showed markedly reduced interference (Fig. 4). Doppler shift compensation was affected by pure tones at the optimum interfering frequency with sound pressure levels down to –48 dB rel the intensity level of the emitted call (Figs. 5, 6).
Narrow bandwidth noise (bandwidth from ± 100 Hz to ± 800 Hz) disturbed Doppler shift compensation at carrier frequencies between –250 Hz below and 800 Hz above RF with a maximum of interference between 250 and 500 Hz above resting frequency (Fig. 7). The duration and delay of the noise had similar influences on interference with Doppler shift compensation as did pure tones (Figs. 8, 9). Intensity dependence for noise interference was more variable than for pure tones (-32 dB to -45 dB rel emitted sound pressure level, Fig. 10).
The temporal and spectral gating in Doppler shift compensation behaviour is discussed as an effective mechanism for clutter rejection by improving the processing of frequency and amplitude transients in the echoes of horseshoe bats
Les parlers acadiens : un continuum discontinu
Nous partons de l'hypothèse que les variétés du français acadien, éloignées les unes des autres en Amérique du Nord depuis longtemps, constitueraient un continuum interlinguistique par l'espace structurel qui les sépare. En plus, toutes les variétés de l'acadien font preuve d'un haut degré de variabilité interne. À partir d'une analyse des restructurations dans quelques sous-systèmes grammaticaux (les propositions conditionnelles, les formes verbales non finies) et de quelques discontinuités par rapport à la présence ou l'absence de certains traits caractéristiques de l'acadien, nous tirons la conclusion que l'espace variationnel acadien se présente comme un exemple complexe de continuités et de discontinuités auquel le modèle scalaire ne peut être appliqué que partiellement.We adopt the hypothesis that the varieties of Acadian French, geographically distant from one another in North America for quite some time, constitute an interlinguistic continuum based on the structural space which separates them. Furthermore, all varieties of Acadian French show a high degree of internal variability. Based on an analysis of the restructuring of a number of grammatical sub-systems (conditional clauses, non-finite verb forms) and of a number of discontinuities concerning the presence or absence of certain features typical of Acadian French, we conclude that the variational space of Acadian French is a complex example of continuities and discontinuities to which the scalar model can only partially be applied
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