Temat: CW FM - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Strain-dependent damping of Ti-10V-2Fe-3Al at room temperature
Autorzy:: Göken, J.
Fayed, S.
Skubisz, P.
Powiązania:: https://bibliotekanauki.pl/articles/1058185.pdf
Data publikacji:: 2016-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.72.Hh
43.40.Cw
43.58.Fm
Opis:: The Ti-10V-2Fe-3Al alloy is advantageous over other titanium grades due to its high tensile strength and its high resistance against creep, cracking, and corrosion. The investigated alloy was hammer-forged inducing high strain rates in the material at a temperature of 800°C and underwent different cooling procedures. Three in that way thermomechanically treated specimens were prepared for subsequent study of the vibration behaviour of the material with the help of non-destructive, contact-free acoustic measurements. Resulting time-dependent decaying acoustic signals were analysed to investigate the dependence of the material damping behaviour on the individual downstream thermal treatment procedure and, ultimately, on the microstructural changes.
Źródło:: Acta Physica Polonica A; 2016, 130, 6; 1352-1357
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Analysis of distance measurement errors in CW FM sonar with MLS code modulation
Autorzy:: Jedel, A.
Marszal, J.
Salamon, R.
Powiązania:: https://bibliotekanauki.pl/articles/331626.pdf
Data publikacji:: 2017
Wydawca:: Polskie Towarzystwo Akustyczne
Tematy:: CW FM sonar
pseudorandom sequence
Doppler effect
sonar parameters
Opis:: Although used in the classic silent sonar, the CW FM sounding signal has a major flaw which is its inaccuracy in determining the distance to a target. The authors of the article have developed a concept of silent sonar using frequency modulation signals switched by pseudorandom codes, already discussed in their previous work. This article presents a detailed analysis of errors in CW FM sonar with pseudo-random sequence code modulation confronted with errors which occur in similar sonar without code modulation.
Źródło:: Hydroacoustics; 2017, 20; 75-84
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Continuous wave sonar with hyperbolic frequency modulation keyed by pseudo-random sequence
Autorzy:: Jedel, A.
Marszal, J.
Salamon, R.
Powiązania:: https://bibliotekanauki.pl/articles/331999.pdf
Data publikacji:: 2016
Wydawca:: Polskie Towarzystwo Akustyczne
Tematy:: CW FM
pseudorandom sequence
Doppler effect
matched filtering
Opis:: A CW FM type sounding signal is used in the classical solution of silent sonar. While the signal provides a relatively simple implementation of digital signal processing, and ensures good detection conditions, unfortunately, in the presence of the Doppler effect, distance measurement results tend to be wrong. This is due to the fact that the received signal’s instantaneous frequency value is dependent both on the distance to the object, and its speed. Sounding signal, as patented by the authors, is a combination of Pseudo-Random Sequences (PRS), and elementary signals of Hyperbolic Frequency Modulation (HFM) type. The structure of this signal is aimed at minimizing measurement error. The article presents the idea of a sounding signal of HFM+PRS type, and the results of computer simulations.
Źródło:: Hydroacoustics; 2016, 19; 185-196
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

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