2,030 research outputs found
Phase synchronization of instrumental music signals
Signal analysis is one of the finest scientific techniques in communication
theory. Some quantitative and qualitative measures describe the pattern of a
music signal, vary from one to another. Same musical recital, when played by
different instrumentalists, generates different types of music patterns. The
reason behind various patterns is the psychoacoustic measures - Dynamics,
Timber, Tonality and Rhythm, varies in each time. However, the psycho-acoustic
study of the music signals does not reveal any idea about the similarity
between the signals. For such cases, study of synchronization of long-term
nonlinear dynamics may provide effective results. In this context, phase
synchronization (PS) is one of the measures to show synchronization between two
non-identical signals. In fact, it is very critical to investigate any other
kind of synchronization for experimental condition, because those are
completely non identical signals. Also, there exists equivalence between the
phases and the distances of the diagonal line in Recurrence plot (RP) of the
signals, which is quantifiable by the recurrence quantification measure
tau-recurrence rate. This paper considers two nonlinear music signals based on
same raga played by two eminent sitar instrumentalists as two non-identical
sources. The psycho-acoustic study shows how the Dynamics, Timber, Tonality and
Rhythm vary for the two music signals. Then, long term analysis in the form of
phase space reconstruction is performed, which reveals the chaotic phase spaces
for both the signals. From the RP of both the phase spaces, tau-recurrence rate
is calculated. Finally by the correlation of normalized tau-recurrence rate of
their 3D phase spaces and the PS of the two music signals has been established.
The numerical results well support the analysis
Excited state dynamics of Michler's ketone: a laser flash photolysis study
Steady state absorption and fluorescence as well as the time resolved absorption studies in the pico and subpicosecond time domain have been performed to characterize the excited singlet and triplet states of Michler's ketone (MK). The nature of the lowest excited singlet (S1) and triplet (T1) states depends on the polarity of the solvent - in nonpolar solvents they have either pure nπ∗ character or mixed character of π ∗ and π π ∗ states but in more polar solvents the states have CT character. Concentration dependence of the shapes of the fluorescence as well the excited singlet and triplet absorption spectra provide the evidence for the association of the MK molecules in the ground state
Effects of organised media on the excited-state proton transfer in 2-(2'-pyridyl)benzimidazole
Absorption and fluorescence characteristics of 2-(2'-pyridyl)benzimidazole (2-PBI) are studied in the presence of α- and β-cyclodextrins (CD) in aqueous solution at two different pHs. Steady-state and time-resolved fluorescence measurements are used for the investigation of the effect of organised media on the excited-state proton transfer reaction in 2-PBI. Semi-empirical CI calculation for the geometry of the molecule reveals that the 2-PBI molecule may be involved in host–guest complex formation with α-CD and β-CD in different configurations. NMR measurements corroborate this, providing information about the orientation of the 2-PBI molecule inside the cavity of the CDs. No complex formation was evident in γ-CD owing to its larger cavity dimension compared to the size of the 2-PBI molecule
Investigation of complete and incomplete fusion in Li+Sn reaction around Coulomb barrier energies
The complete and incomplete fusion cross sections for Li+Sn
reaction were measured using online and offline characteristic -ray
detection techniques. The complete fusion (CF) cross sections at energies above
the Coulomb barrier were found to be suppressed by 26 \% compared to the
coupled channel calculations. This suppression observed in complete fusion
cross sections is found to be commensurate with the measured total incomplete
fusion (ICF) cross sections. There is a distinct feature observed in the ICF
cross sections, i.e., -capture is found to be dominant than
-capture at all the measured energies. A simultaneous explanation of
complete, incomplete and total fusion (TF) data was also obtained from the
calculations based on Continuum Discretized Coupled Channel method with short
range imaginary potentials. The cross section ratios of CF/TF and ICF/TF
obtained from the data as well as the calculations showed the dominance of ICF
at below barrier energies and CF at above barrier energies.Comment: 9 pages, 8 figure
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