The steady-state visual evoked potential (SSVEP) detection technology is more suitable for real-time brain-computer interface (BCI) systems due to its easy feature recognition, short response time, ...and high stability. Classic algorithms for SSVEP recognition such as the CCA and FBCCA methods require the construction of EEG templates and the spatial filtering of multi-electrode EEG data, which cannot obtain a satisfactory performance of SSVEP-EEG detection technology. To address this issue, we compared several stochastic resonance (SR) models in terms of potential functions and phase plane structures and utilized these models to enhance the amplitude and the energy of feature frequencies, thereby improving the recognition accuracy in SSVEP tasks. In our study, the SSVEP experiment recruited 34 subjects to evaluate and compare the validity of several SR models. Experimental results showed that SR-based methods can achieve higher detection accuracy and faster calculation speed compared with other traditional methods. Meanwhile, among these SR models, the underdamped second-order SR and FitzHugh–Nagumo SR have more outstanding characteristics for SSVEP-based BCIs.
It is commonplace to recount the history of quantum physics on the basis of phenomena that have found no satisfactory explanation in the context of so‐called classical physics. This is the case of, ...for example, blackbody radiation, the photoelectric effect, specific heats, and series of spectral lines. This story goes in another direction: new knowledge about quantum physics not only emerged from the need to explain new phenomena that conflicted with old theoretical structures, but also from the attempts to provide a quantum explanation of phenomena, like optical dispersion, which for a long time had found a very convincing explanation in old physical models, such as the resonance model. The boundary between classical and quantum domains of knowledge was not fixed a priori, but historically negotiated in the context of specific problems, including the problem of optical dispersion.
The establishment of boundaries between classical and quantum physics is not a self‐evident fact, but the result of an historical process. A relevant historical episode is analyzed from this viewpoint: the challenging problem of understanding optical dispersion in the context of Niels Bohr's quantum model of the atom, published in 1913, and its role in the quantum revolution.
The results from various dijet distributions in proton–proton collisions at a centre-of-mass energy of 7 TeV, with 2010 and 2011 data from the CMS experiment, are presented. The measurements of the ...dijet mass spectra, centrality ratio, azimuthal decorrelation and angular distribution are shown. Sensitivity of the phenomenological parameters used to model different event generators is also investigated. Prospects for observing evidence for new physics in these distributions are presented.
Lexical-decision studies with experienced English and French readers have shown that visual-word identification is not only affected by pronunciation inconsistency of a word (i.e., multiple ways to ...pronounce a spelling body), but also by spelling inconsistency (i.e., multiple ways to spell a pronunciation rime). The aim of this study was to compare the reading behavior of young Dutch readers with dyslexia to the behavior of readers without dyslexia. All students participated in a lexical-decision task in which we presented pronunciation-consistent words and pseudowords. Half of the pronunciation-consistent stimuli were spelling consistent and the other half were spelling inconsistent. All three reader groups, that is, students with dyslexia, age-match students, and reading-match students, read spelling-consistent words faster than spelling-inconsistent words. Overall reading speed of students with dyslexia was similar to that of reading-match students, and was substantially slower than that of age-match students. The results suggest that reading in students with or without dyslexia is similarly affected by spelling inconsistency. Subtle qualitative differences emerged, however, with respect to pseudoword identification. The conclusion was that the findings were best interpreted in terms of a recurrent-feedback model.
In this study, piezoelectric acoustic absorbers employing two receivers and one transmitter with a feedback controller were evaluated. Based on the target and resonance frequencies of the system, ...resonance and non-resonance models were designed and fabricated. With a lateral size less than half the wavelength, the model had stacked structures of lossy acoustic windows, polyvinylidene difluoride, and lead zirconate titanate-5A. The structures of both models were identical, except that the resonance model had steel backing material to adjust the center frequency. Both models were analyzed in the frequency and time domains, and the effectiveness of the absorbers was compared at the target and off-target frequencies. Both models were fabricated and acoustically and electrically characterized. Their reflection reduction ratios were evaluated in the quasi-continuous-wave and time-transient modes.
•A spherical phononic crystal model with ultra-wide low frequency bandgap is designed.•The bandgap opening and merging behavior of hybrid phononic crystals model is analyzed.•An effective torsional ...vibration equivalent model and frequency calculating formula are proposed.
A self-contained theoretical analysis of the bandgap opening and merging behavior for the designed phononic crystal model which is composed of three-component coated ball and four short connecting plates is reported in this study by finite element numerical simulations. The results show that there are multiple bandgaps of the designed model in the middle and low frequency range simultaneously. The structure symmetry is reduced to open a new bandgap via the separation of resonance modes, and an ultra-wide bandgap obtained. Especially, the equivalent spring mass model is constructed and the corresponding calculation formula of torsional resonance frequency is presented. In addition, the influence of the structural parameters on the band structure is investigated.
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